Heritage Medical Research Clinic

BACKGROUND: Chronic hepatitis C virus (HCV) infection in patients with cirrhosis is difficult to treat. In patients with chronic hepatitis C but without cirrhosis, once-weekly administration of interferon modified by the attachment of a 40-kd branched-chain polyethylene glycol moiety (peginterferon alfa-2a) is more efficacious than a regimen of unmodified interferon. We examined the efficacy and safety of peginterferon alfa-2a in patients with HCV-related cirrhosis or bridging fibrosis. METHODS: We randomly assigned 271 patients with cirrhosis or bridging fibrosis to receive subcutaneous treatment with 3 million units of interferon alfa-2a three times weekly (88 patients), 90 microg of peginterferon alfa-2a once weekly (96), or 180 microg of peginterferon alfa-2a once weekly (87). Treatment lasted 48 weeks and was followed by a 24-week follow-up period. We assessed efficacy by measuring HCV RNA and alanine aminotransferase and by evaluating liver-biopsy specimens. A histologic response was defined as a decrease of at least 2 points on the 22-point Histological Activity Index. RESULTS: In an intention-to-treat analysis, HCV RNA was undetectable at week 72 in 8 percent, 15 percent, and 30 percent of the patients treated with interferon alfa-2a and with 90 microg and 180 microg of peginterferon alfa-2a, respectively (P=0.001 for the comparison between 180 microg of peginterferon alfa-2a and interferon alfa-2a). At week 72, alanine aminotransferase concentrations had normalized in 15 percent, 20 percent, and 34 percent of patients, respectively (P=0.004 for the comparison between 180 microg of peginterferon alfa-2a and interferon alfa-2a). In the subgroup of 184 patients with paired liver-biopsy specimens, the rates of histologic response at week 72 were 31 percent, 44 percent, and 54 percent, respectively (P=0.02 for the comparison between 180 microg of peginterferon alfa-2a and interferon alfa-2a). All three treatments were similarly tolerated. CONCLUSIONS: In patients with chronic hepatitis C and cirrhosis or bridging fibrosis, 180 microg of peginterferon alfa-2a administered once weekly is significantly more effective than 3 million units of standard interferon alfa-2a administered three times weekly.

1. We have investigated whether the myocardium and isolated cardiac myocytes can express a Ca(2+)-independent NO synthase after treatment with endotoxin or cytokines. Nitric oxide synthesis was measured in cytosols from the left ventricular wall from rats treated with endotoxin, or from freshly isolated myocytes from adult rats treated in vitro with cytokines. 2. Cytosols from the ventricle of saline-treated control animals showed only Ca(2+)-dependent NO synthesis. After treatment with endotoxin, the expression of an inducible, Ca(2+)-independent NO synthase was observed. The activity of this enzyme was maximal at 6 h and returned towards control levels by 18 h; no alterations occurred in the Ca(2+)-dependent NO synthase activity. Parallel to this enzyme induction there was an increase in myocardial guanosine 3':5'-cyclic monophosphate (cyclic GMP) and plasma nitrite and nitrate (NOx-). All these changes were prevented by pretreatment of the rats with dexamethasone. 3. Myocytes possessed Ca(2+)-dependent NO synthase activity and expressed, after treatment with tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta), a Ca(2+)-independent NO synthase, the induction of which was prevented by dexamethasone and cycloheximide. 4. Since increases in cyclic GMP levels in the heart are associated with reduced myocardial contractility, it is possible that the enhanced production of NO by a Ca(2+)-independent enzyme accounts, at least in part, for the depression of myocardial contractility seen in septic shock, cardiomyopathies, allograft rejection, burn trauma, as well as during anti-tumour therapy with cytokines.

The (-) enantiomer of 3'-thiacytidine (lamivudine) has been found to be a potent inhibitor of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) replication. Mutation of methionine to valine or isoleucine at the YMDD (tyrosine, methionine, aspartate, aspartate) motif of the HIV reverse transcriptase has been shown to be responsible for lamivudine resistance in HIV. The hepadnaviruses also have the YMDD motif in their DNA polymerase. Therefore, it is possible that hepadnaviruses could develop lamivudine resistance by a similar mutation at this motif. We analyzed the HBV from a liver transplantation patient who developed recurrent HBV viremia during lamivudine treatment. The polymerase gene was amplified by polymerase chain reaction (PCR), and the region coding for the YMDD motif was sequenced. The pretreatment HBV sequence coded for YMDD, while the lamivudine-resistant mutant HBV coded for YIDD (tyrosine, isoleucine, aspartate, aspartate). With the documented changes in the YMDD motif of lamivudine-resistant HIV, it is likely that the methionine-to-isoleucine mutation in the YMDD motif of the HBV polymerase contributes significantly to the lamivudine-resistance of HBV isolated from this patient.

Electrical stimulation promotes the speed and accuracy of motor axonal regeneration. The positive effects of stimulation are mediated at the cell body. Here we characterize the effect of electrical stimulation on motoneuronal expression of BDNF and its receptor, trkB, two genes whose expression levels in motoneurons correlate with regeneration and are regulated by electrical activity in a variety of neurons. We used semiquantitative in situ hybridization to measure expression of mRNA encoding BDNF and the full-length trkB receptor at intervals of 8 h, 2 days and 7 days after unilateral femoral nerve cut, suture, and stimulation. Expression in regenerating motoneurons was compared to that of contralateral intact motoneurons. BDNF and trkB signals were not significantly upregulated 8 h and 2 days after femoral nerve suture and sham stimulation. By 7 days, there was a 2-fold increase in both BDNF and trkB mRNA expression. In contrast, stimulation of cut and repaired nerves for only 1 h led to rapid upregulation of BDNF and trkB mRNA by 3-fold and 2-fold, respectively, within the first 8 h. The stimulation effect peaked at 2 days with 6-fold and 4-fold increases in the signals, respectively. Thereafter, the levels of BDNF and trkB mRNA expression declined to equal the 2-fold increase seen at 7 days after nerve repair and sham-stimulation. We conclude that brief electrical stimulation stimulates BDNF and trkB expression in regenerating motoneurons. Because electrical stimulation is known to accelerate axonal regeneration, we suggest that changes in the expression of BDNF and trkB correlate with acceleration of axonal regeneration.

BACKGROUND: Few studies have prospectively and systematically explored the factors that acutely precipitate exacerbation of congestive heart failure (CHF) in patients with left ventricular dysfunction. Knowledge of such factors is important in designing measures to prevent deterioration of clinical status. The objective of this study was to prospectively describe the precipitants associated with exacerbation of CHF status in patients enrolled in the Randomized Evaluation of Strategies for Left Ventricular Dysfunction Pilot Study. METHODS: We conducted a 2-stage, multicenter, randomized trial in 768 patients with CHF who had an ejection fraction of less than 40%. Patients were randomly assigned to receive enalapril maleate, candesartan cilexetil, or both for 17 weeks, followed by randomization to receive metoprolol succinate or placebo for 26 weeks. Investigators systematically documented information on clinical presentation, management, and factors associated with the exacerbation for any episode of acute CHF during follow-up. RESULTS: A total of 323 episodes of worsening of CHF occurred in 180 patients during 43 weeks of follow-up; 143 patients required hospitalization, and 5 died. Factors implicated in worsening of CHF status included noncompliance with salt restriction (22%); other noncardiac causes (20%), notably pulmonary infectious processes; study medications (15%); use of antiarrhythmic agents in the past 48 hours (15%); arrhythmias (13%); calcium channel blockers (13%); and inappropriate reductions in CHF therapy (10%). CONCLUSIONS: A variety of factors, many of which are avoidable, are associated with exacerbation of CHF. Attention to these factors and patient education are important in the prevention of CHF deterioration.

BACKGROUND: Despite clear evidence for the efficacy of lowering cholesterol levels, there is a deficiency in its real-world application. There is a need to explore alternative strategies to address this important public health problem. This study aimed to determine the effect of a program of community pharmacist intervention on the process of cholesterol risk management in patients at high risk for cardiovascular events. METHODS: A randomized controlled trial conducted in 54 community pharmacies (1998-2000) included patients at high risk for cardiovascular events (with atherosclerotic disease or diabetes mellitus with another risk factor). Patients randomized to pharmacist intervention received education and a brochure on risk factors, point-of-care cholesterol measurement, referral to their physician, and regular follow-up for 16 weeks. Pharmacists faxed a simple form to the primary care physician identifying risk factors and any suggestions. Usual care patients received the same brochure and general advice only, with minimal follow-up. The primary end point was a composite of performance of a fasting cholesterol panel by the physician or addition or increase in dose of cholesterol-lowering medication. RESULTS: The external monitoring committee recommended early study termination owing to benefit. Of the 675 patients enrolled, approximately 40% were women, and the average age was 64 years. The primary end point was reached in 57% of intervention patients vs 31% in usual care (odds ratio, 3.0; 95% confidence interval, 2.2-4.1; P<.001). CONCLUSIONS: A community-based intervention program improved the process of cholesterol management in high-risk patients. This program demonstrates the value of community pharmacists working in collaboration with patients and physicians.

Matrix metalloproteinase (MMP)-2 belongs to a family of zinc-dependent proteases which are best known for their ability to proteolyse extracellular matrix proteins throughout the body, including the cardiovascular system. Increased MMP-2 activity has been demonstrated in myocardial ischaemia and reperfusion injury and the progression to congestive heart failure, with most evidence to date for its role in cardiac remodelling. Recent evidence, however, shows that MMP-2 also co-localizes with and proteolyses specific protein targets within the cardiomyocyte to cause acute, reversible contractile dysfunction, challenging the conventional wisdom on the 'extracellular matrix only' actions of this enzyme. In this review, we discuss the recent upsurge in MMP-2 research with regards to its activation by non-proteolytic pathways in the setting of enhanced oxidative stress in the heart. We will focus on the consequences of intracellular actions of MMP-2 within the cardiomyocyte and its regulation at several levels including its expression, post-translational modifications, and regulation by endogenous tissue inhibitors of metalloproteinases, caveolin, and small molecule MMP inhibitors. MMP-2 is emerging as an important signalling protease implicated in the proteolytic regulation of various intracellular proteins in myocardial oxidative stress injury.

Assays for two distinct phosphatidate phosphohydrolase activities were established based upon a differential inhibition by N-ethylmaleimide (NEM). The activity that is insensitive to this reagent in rat liver is predominantly in the plasma membrane fraction, whereas the NEM-sensitive activity is in the cytosolic and microsomal fractions. The NEM-insensitive activity is further distinguished from the NEM-sensitive phosphohydrolase by: (a) being relatively stable to heat; (b) not being inhibited by phenylglyoxal, butane-2,3-dione, cyclohexane-1,2-dione, 2,4-dinitrofluorobenzene, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole, and diethyl pyrocarbonate; (c) being inhibited by NaF and phosphatidylcholine; and (d) not being stimulated by Mg2+. The NEM-insensitive activity was specific for phosphatidate. Both phosphohydrolase activities could be inhibited by chlorpromazine, propranolol, sphingosine, and spermine. The NEM-sensitive phosphatidate phosphohydrolase activity was increased by incubating hepatocytes for 12 h with glucagon and dexamethasone, and this effect was antagonized by insulin. The NEM-sensitive phosphohydrolase is concluded to be involved in glycerolipid synthesis. The activity of the NEM-insensitive phosphohydrolase was not altered by preincubation of rat hepatocytes in the short or long term with vasopressin, glucagon, insulin, triiodothyronine, or dexamethasone, but it might be modulated indirectly by sphingosine. The NEM-insensitive enzyme of the plasma membranes could be involved in signal transduction via the agonist-stimulated degradation of phosphatidylcholine through the phospholipase D pathway.

The XVI-th Banff Meeting for Allograft Pathology was held at Banff, Alberta, Canada, from 19th to 23rd September 2022, as a joint meeting with the Canadian Society of Transplantation. To mark the 30th anniversary of the first Banff Classification, premeeting discussions were held on the past, present, and future of the Banff Classification. This report is a summary of the meeting highlights that were most important in terms of their effect on the Classification, including discussions around microvascular inflammation and biopsy-based transcript analysis for diagnosis. In a postmeeting survey, agreement was reached on the delineation of the following phenotypes: (1) "Probable antibody-mediated rejection (AMR)," which represents donor-specific antibodies (DSA)-positive cases with some histologic features of AMR but below current thresholds for a definitive AMR diagnosis; and (2) "Microvascular inflammation, DSA-negative and C4d-negative," a phenotype of unclear cause requiring further study, which represents cases with microvascular inflammation not explained by DSA. Although biopsy-based transcript diagnostics are considered promising and remain an integral part of the Banff Classification (limited to diagnosis of AMR), further work needs to be done to agree on the exact classifiers, thresholds, and clinical context of use.

Matrix metalloproteinases (MMPs) are traditionally known for their role in extracellular matrix remodeling. Increasing evidence reveals several alternative substrates and novel biological roles for these proteases. Recent evidence showed the intracellular localization of MMP-2 within cardiac myocytes, colocalized with troponin I within myofilaments. Here we investigated the presence of MMP-2 in the nucleus of cardiac myocytes using both immunogold electron microscopy and biochemical assays with nuclear extracts. The gelatinase activity found in both human heart and rat liver nuclear extracts was blocked with MMP inhibitors. In addition, the ability of MMP-2 to cleave poly (ADP-ribose) polymerase (PARP) as a substrate was examined as a possible role for MMP-2 in the nucleus. PARP is a nuclear matrix enzyme involved in the repair of DNA strand breaks, which is known to be inactivated by proteolytic cleavage. PARP was susceptible to cleavage by MMP-2 in vitro in a concentration-dependent manner, yielding novel degradation products of ~66 and <45 kDa. The cleavage of PARP by MMP-2 was also blocked by MMP inhibitors. This is the first characterization of MMP-2 within the nucleus and we hereby suggest its possible role in PARP degradation.

Despite the high expression of 5'AMP activated protein kinase (AMPK) in heart, the activity and function of this enzyme in heart muscle has not been characterized. We demonstrate that rat hearts have a high AMPK activity, comparable to that found in liver, which could be stimulated up to 3-fold by 5'AMP. Cardiac AMPK is also under phosphorylation control, since in vitro incubation of cardiac AMPK with protein phosphatase 2A completely abolished activity, while incubation with ATP/Mg(2+) resulted in over a 2-fold increase in activity. To investigate the function of AMPK in heart muscle, isolated working rat hearts were subjected to 30 min of global no-flow ischemia, followed by 60 min of aerobic reperfusion. AMPK activity was increased in heart at the end of reperfusion compared to aerobic controls (379 +/- 53 (n=5) vs. 139 +/- 19 (n=5) pmol x min(-1) x mg protein(-1), P<0.05, respectively). Treatment of AMPK in vitro with protein phosphatase 2A reversed this activation. Since AMPK can phosphorylate and inactivate acetyl-CoA carboxylase (ACC) in other tissues, and heart ACC has an important role in regulating fatty acid oxidation, we measured ACC activity in hearts reperfused post-ischemia. ACC activity was decreased at the end of reperfusion compared to aerobic controls (3.64 +/- 0.36 (n=9) vs. 10.93 +/- 0.60 (n=11) nmol x min(-1) x mg protein(-1), respectively, P<0.05). A significant negative correlation (r= -0.78) was observed between AMPK activity and ACC activity measured in aerobic and reperfused ischemic hearts. Low ACC activity could be reversed if ACC was extracted from hearts in the absence of phosphatase inhibitors, suggesting that phosphorylation of ACC decreased enzyme activity. This suggests that following ischemia AMPK is phosphorylated and activated (possibly by an AMPK kinase). AMPK then phosphorylates and inactivates ACC. The resultant decrease in malonyl-CoA levels could explain the acceleration of fatty acid oxidation that is observed during reperfusion of ischemic hearts.

BACKGROUND: This is an update of a Cochrane Review first published in 1999. Corticosteroids are widely used in inflammatory conditions as an immunosuppressive agent. Bone loss is a serious side effect of this therapy. Several studies have examined the use of bisphosphonates in the prevention and treatment of glucocorticosteroid-induced osteoporosis (GIOP) and have reported varying magnitudes of effect. OBJECTIVES: To assess the benefits and harms of bisphosphonates for the prevention and treatment of GIOP in adults. SEARCH METHODS: We searched CENTRAL, MEDLINE and Embase up to April 2016 and International Pharmaceutical Abstracts (IPA) via OVID up to January 2012 for relevant articles and conference proceedings with no language restrictions. We searched two clinical trial registries for ongoing and recently completed studies (ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal). We also reviewed reference lists of relevant review articles. SELECTION CRITERIA: We included randomised controlled trials (RCTs) satisfying the following criteria: 1) prevention or treatment of GIOP; 2) adults taking a mean steroid dose of 5.0 mg/day or more; 3) active treatment including bisphosphonates of any type alone or in combination with calcium or vitamin D; 4) comparator treatment including a control of calcium or vitamin D, or both, alone or with placebo; and 4) reporting relevant outcomes. We excluded trials that included people with transplant-associated steroid use. DATA COLLECTION AND ANALYSIS: At least two review authors independently selected trials for inclusion, extracted data, performed 'risk of bias' assessment and evaluated the certainty of evidence using the GRADE approach. Major outcomes of interest were the incidence of vertebral and nonvertebral fractures after 12 to 24 months; the change in bone mineral density (BMD) at the lumbar spine and femoral neck after 12 months; serious adverse events; withdrawals due to adverse events; and quality of life. We used standard Cochrane methodological procedures. MAIN RESULTS: We included a total of 27 RCTs with 3075 participants in the review. Pooled analysis for incident vertebral fractures included 12 trials (1343 participants) with high-certainty evidence and low risk of bias. In this analysis 46/597 (or 77 per 1000) people experienced new vertebral fractures in the control group compared with 31/746 (or 44 per 1000; range 27 to 70) in the bisphosphonate group; relative improvement of 43% (9% to 65% better) with bisphosphonates; absolute increased benefit of 2% fewer people sustaining fractures with bisphosphonates (5% fewer to 1% more); number needed to treat for an additional beneficial outcome (NNTB) was 31 (20 to 145) meaning that approximately 31 people would need to be treated with bisphosphonates to prevent new vertebral fractures in one person.Pooled analysis for incident nonvertebral fractures included nine trials with 1245 participants with low-certainty evidence (downgraded for imprecision and serious risk of bias as a patient-reported outcome). In this analysis 30/546 (or 55 per 1000) people experienced new nonvertebral fracture in the control group compared with 29/699 (or 42 per 1000; range 25 to 69) in the bisphosphonate group; relative improvement of 21% with bisphosphonates (33% worse to 53% better); absolute increased benefit of 1% fewer people with fractures with bisphosphonates (4% fewer to 1% more).Pooled analysis on BMD change at the lumbar spine after 12 months included 23 trials with 2042 patients. Eighteen trials with 1665 participants were included in the pooled analysis on BMD at the femoral neck after 12 months. Evidence for both outcomes was moderate-certainty (downgraded for indirectness as a surrogate marker for osteoporosis) with low risk of bias. Overall, the bisphosphonate groups reported stabilisation or increase in BMD, while the control groups showed decreased BMD over the study period. At the lumbar spine, there was an absolute increase in BMD of 3.5% with bisphosphonates (2.90% to 4.10% higher) with a relative improvement of 1.10% with bisphosphonates (0.91% to 1.29%); NNTB 3 (2 to 3). At the femoral neck, the absolute difference in BMD was 2.06% higher in the bisphosphonate group compared to the control group (1.45% to 2.68% higher) with a relative improvement of 1.29% (0.91% to 1.69%); NNTB 5 (4 to 7).Pooled analysis on serious adverse events included 15 trials (1703 participants) with low-certainty evidence (downgraded for imprecision and risk of bias). In this analysis 131/811 (or 162 per 1000) people experienced serious adverse events in the control group compared to 136/892 (or 147 per 1000; range 120 to 181) in the bisphosphonate group; absolute increased harm of 0% more serious adverse events (2% fewer to 2% more); a relative per cent change with 9% improvement (12% worse to 26% better).Pooled analysis for withdrawals due to adverse events included 15 trials (1790 patients) with low-certainty evidence (downgraded for imprecision and risk of bias). In this analysis 63/866 (or 73 per 1000) people withdrew in the control group compared to 76/924 (or 77 per 1000; range 56 to 107) in the bisphosphonate group; an absolute increased harm of 1% more withdrawals with bisphosphonates (95% CI 1% fewer to 3% more); a relative per cent change 6% worse (95% CI 47% worse to 23% better).Quality of life was not assessed in any of the trials. AUTHORS' CONCLUSIONS: There was high-certainty evidence that bisphosphonates are beneficial in reducing the risk of vertebral fractures with data extending to 24 months of use. There was low-certainty evidence that bisphosphonates may make little or no difference in preventing nonvertebral fractures. There was moderate-certainty evidence that bisphosphonates are beneficial in preventing and treating corticosteroid-induced bone loss at both the lumbar spine and femoral neck. Regarding harm, there was low-certainty evidence that bisphosphonates may make little or no difference in the occurrence of serious adverse events or withdrawals due to adverse events. We are cautious in interpreting these data as markers for harm and tolerability due to the potential for bias.Overall, our review supports the use of bisphosphonates to reduce the risk of vertebral fractures and the prevention and treatment of steroid-induced bone loss.

BACKGROUND: Human immunodeficiency virus type 1(HIV-1) infects and activates innate immune cells in the brain resulting in inflammation and neuronal death with accompanying neurological deficits. Induction of inflammasomes causes cleavage and release of IL-1β and IL-18, representing pathogenic processes that underlie inflammatory diseases although their contribution HIV-associated brain disease is unknown. RESULTS: Investigation of inflammasome-associated genes revealed that IL-1β, IL-18 and caspase-1 were induced in brains of HIV-infected persons and detected in brain microglial cells. HIV-1 infection induced pro-IL-1β in human microglia at 4 hr post-infection with peak IL-1β release at 24 hr, which was accompanied by intracellular ASC translocation and caspase-1 activation. HIV-dependent release of IL-1β from a human macrophage cell line, THP-1, was inhibited by NLRP3 deficiency and high extracellular [K+]. Exposure of microglia to HIV-1 gp120 caused IL-1β production and similarly, HIV-1 envelope pseudotyped viral particles induced IL-1β release, unlike VSV-G pseudotyped particles. Infection of cultured feline macrophages by the related lentivirus, feline immunodeficiency virus (FIV), also resulted in the prompt induction of IL-1β. In vivo FIV infection activated multiple inflammasome-associated genes in microglia, which was accompanied by neuronal loss in cerebral cortex and neurological deficits. Multivariate analyses of data from FIV-infected and uninfected animals disclosed that IL-1β, NLRP3 and caspase-1 expression in cerebral cortex represented key molecular determinants of neurological deficits. CONCLUSIONS: NLRP3 inflammasome activation was an early and integral aspect of lentivirus infection of microglia, which was associated with lentivirus-induced brain disease. Inflammasome activation in the brain might represent a potential target for therapeutic interventions in HIV/AIDS.

High-throughput technologies have led to advances in the recognition of disease pathways and their underlying mechanisms. To investigate the impact of micro-RNAs on the disease process in multiple sclerosis, a prototypic inflammatory neurological disorder, we examined cerebral white matter from patients with or without the disease by micro-RNA profiling, together with confirmatory reverse transcription-polymerase chain reaction analysis, immunoblotting and gas chromatography-mass spectrometry. These observations were verified using the in vivo multiple sclerosis model, experimental autoimmune encephalomyelitis. Brains of patients with or without multiple sclerosis demonstrated differential expression of multiple micro-RNAs, but expression of three neurosteroid synthesis enzyme-specific micro-RNAs (miR-338, miR-155 and miR-491) showed a bias towards induction in patients with multiple sclerosis (P < 0.05). Analysis of the neurosteroidogenic pathways targeted by micro-RNAs revealed suppression of enzyme transcript and protein levels in the white matter of patients with multiple sclerosis (P < 0.05). This was confirmed by firefly/Renilla luciferase micro-RNA target knockdown experiments (P < 0.05) and detection of specific micro-RNAs by in situ hybridization in the brains of patients with or without multiple sclerosis. Levels of important neurosteroids, including allopregnanolone, were suppressed in the white matter of patients with multiple sclerosis (P < 0.05). Induction of the murine micro-RNAs, miR-338 and miR-155, accompanied by diminished expression of neurosteroidogenic enzymes and allopregnanolone, was also observed in the brains of mice with experimental autoimmune encephalomyelitis (P < 0.05). Allopregnanolone treatment of the experimental autoimmune encephalomyelitis mouse model limited the associated neuropathology, including neuroinflammation, myelin and axonal injury and reduced neurobehavioral deficits (P < 0.05). These multi-platform studies point to impaired neurosteroidogenesis in both multiple sclerosis and experimental autoimmune encephalomyelitis. The findings also indicate that allopregnanolone and perhaps other neurosteroid-like compounds might represent potential biomarkers or therapies for multiple sclerosis.

This study examined the relationship between cerebral blood flow (CBF) and end-tidal PCO2 (PETCO2) in humans. We used transcranial Doppler ultrasound to determine middle cerebral artery peak blood velocity responses to 14 levels of PETCO2 in a range of 22 to 50 Torr with a constant end-tidal PO2 (100 Torr) in eight subjects. PETCO2 and end-tidal PO2 were controlled by using the technique of dynamic end-tidal forcing combined with controlled hyperventilation. Two protocols were conducted in which PETCO2 was changed by 2 Torr every 2 min from hypocapnia to hypercapnia (protocol I) and vice-versa (protocol D). Over the range of PETCO2 studied, the sensitivity of peak blood velocity to changes in PETCO2 (CBF-PETCO2 sensitivity) was nonlinear with a greater sensitivity in hypercapnia (4.7 and 4.0%/Torr, protocols I and D, respectively) compared with hypocapnia (2.5 and 2.2%/Torr). Furthermore, there was evidence of hysteresis in the CBF-PETCO2 sensitivity; for a given PETCO2, there was greater sensitivity during protocol I compared with protocol D. In conclusion, CBF-PETCO2 sensitivity varies depending on the level of PETCO2 and the protocol that is used. The mechanisms underlying these responses require further investigation.

OBJECTIVES: [corrected] This analysis estimated the gender-specific associations between work stress, major depression, anxiety disorders and any mental disorder, adjusting for the effects of demographic, socioeconomic, psychological and clinical variables. METHODS: Data from the Canadian national mental health survey were used to examine the gender-specific relationships between work stress dimensions and mental disorders in the working population (n = 24,277). Mental disorders were assessed using a modified version of the World Mental Health - Composite International Diagnostic Interview. RESULTS: In multivariate analysis, male workers who reported high demand and low control in the workplace were more likely to have had major depression (OR 1.74, 95% CI 1.12 to 2.69) and any depressive or anxiety disorders (OR 1.47, 95% CI 1.05 to 2.04) in the past 12 months. In women, high demand and low control was only associated with having any depressive or anxiety disorder (OR 1.39, 95% CI 1.05 to 1.84). Job insecurity was positively associated with major depression in men but not in women. Imbalance between work and family life was the strongest factor associated with having mental disorders, regardless of gender. CONCLUSIONS: Policies improving the work environment may have positive effects on workers' mental health status. Imbalance between work and family life may be a stronger risk factor than work stress for mental disorders. Longitudinal studies incorporating important workplace health research models are needed to delineate causal relationships between work characteristics and mental disorders.

The (-) enantiomer of 3'-thiacytidine (lamivudine) has been found to be a potent inhibitor of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) replication. Mutation of methionine to valine or isoleucine at the YMDD (tyrosine, methionine, aspartate, aspartate) motif of the HIV reverse transcriptase has been shown to be responsible for lamivudine resistance in HIV. The hepadnaviruses also have the YMDD motif in their DNA polymerase. Therefore, it is possible that hepadnaviruses could develop lamivudine resistance by a similar mutation at this motif. We analyzed the HBV from a liver transplantation patient who developed recurrent HBV viremia during lamivudine treatment. The polymerase gene was amplified by polymerase chain reaction (PCR), and the region coding for the YMDD motif was sequenced. The pretreatment HBV sequence coded for YMDD, while the lamivudine-resistant mutant HBV coded for YIDD (tyrosine, isoleucine, aspartate, aspartate). With the documented changes in the YMDD motif of lamivudine-resistant HIV, it is likely that the methionine-to- isoleucine mutation in the YMDD motif of the HBV polymerase contributes significantly to the lamivudine-resistance of HBV isolated from this patient. (Hepatology 1996 Sep;24(3):714-7)

Pancreatic islet transplantation is a viable treatment for type 1 diabetes, but is limited by human donor tissue availability. The combination of epidermal growth factor (EGF) and gastrin induces islet beta-cell neogenesis from pancreatic exocrine duct cells in rodents. In this study we investigated whether EGF and gastrin could expand the beta-cell mass in adult human isolated islets that contain duct as well as endocrine cells. Human islet cells were cultured for 4 wk in serum-free medium (control) or in medium with EGF (0.3 mug/ml), gastrin (1.0 mug/ml), or the combination of EGF and gastrin. beta-Cell numbers were increased in cultures with EGF plus gastrin (+118%) and with EGF (+81%), but not in cultures with gastrin (-3%) or control medium (-62%). After withdrawal of EGF and gastrin and an additional 4 wk in control medium, beta-cell numbers continued to increase only in cultures previously incubated with both EGF and gastrin (+232%). EGF plus gastrin also significantly increased cytokeratin 19-positive duct cells (+678%) in the cultures. Gastrin, alone or in combination with EGF, but not EGF alone, increased the expression of pancreatic and duodenal homeobox factor-1 as well as insulin and C peptide in the cytokeratin 19-positive duct cells. Also, EGF plus gastrin significantly increased beta-cells and insulin content in human islets implanted in immunodeficient nonobese diabetic-severe combined immune deficiency mice as well as insulin secretory responses of the human islet grafts to glucose challenge. In conclusion, combination therapy with EGF and gastrin increases beta-cell mass in adult human pancreatic islets in vitro and in vivo, and this appears to result from the induction of beta-cell neogenesis from pancreatic exocrine duct cells.

BACKGROUND: Cytogenetic abnormalities have been known to be important causes of male infertility for decades. METHODS: Research publications from 1978 to 2008, from PubMed, have been reviewed. RESULTS: These studies have greatly improved our information on somatic chromosomal abnormalities such as translocations, inversions and sex chromosomal anomalies, and their consequences to the cytogenetic make-up of human sperm. Also, we have learned that infertile men with a normal somatic karyotype have an increased risk of chromosomally abnormal sperm and children. New techniques such as single sperm typing and synaptonemal complex analysis have provided valuable insight into the association between meiotic recombination and the production of aneuploid sperm. These meiotic studies have also unveiled errors of chromosome pairing and synapsis, which are more common in infertile men. CONCLUSIONS: These studies allow us to provide more precise information to infertile patients, and further our basic knowledge in the causes of male infertility.

OBJECTIVE: There is an unmet need for reliable assessment of structural progression in the sacroiliac joints (SIJ) of patients with spondyloarthritis (SpA), but radiography is unreliable and lacks responsiveness. We aimed to develop and validate a new scoring method for structural lesions based on magnetic resonance imaging (MRI), the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ Structural Score (SSS). METHODS: The SSS method for assessment of structural lesions is based on T1-weighted spin echo MRI, validated lesion definitions, slice selection according to well-defined anatomical principles, and dichotomous scoring (lesion present/absent) of 5 consecutive slices through the cartilaginous portion of the joint. Scoring ranges are fat metaplasia (0-40), erosion (0-40), backfill (0-20), and ankylosis (0-20). We progressively conducted 3 validation exercises with 2-4 readers on baseline, and either 2-year (exercises 1 and 2) or 1-year (exercise 3) scans from 147 patients with SpA assessed blinded to timepoint. Interobserver reliability was assessed by intraclass correlation coefficient (ICC) and smallest detectable change (SDC). RESULTS: Interobserver reliability for status score was good to excellent for ankylosis (ICC 0.79-0.98), consistently good for fat metaplasia (ICC 0.71-0.78), moderate to good for erosion (ICC 0.58-0.62), and fair to good for backfill (ICC 0.35-0.66). Reliability for change scores was moderate to good for all structural lesions despite the relatively small changes in scores, and was highest for fat metaplasia when both ICC and SDC values were compared. CONCLUSION: The new SPARCC MRI SSS method can detect structural changes in the SIJ with acceptable reliability over a 1-2-year timeframe, and should be further validated in patients with SpA.