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Houston Community College System

UniversityHouston, Texas, United States

Research output, citation impact, and the most-cited recent papers from Houston Community College System (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
570
Citations
6.1K
h-index
34
i10-index
149
Also known as
Houston Community CollegeHouston Community College System

Top-cited papers from Houston Community College System

Community Health Workers: Part Of The Solution
E. Lee Rosenthal, J. Nell Brownstein, Carl H. Rush, Gail Hirsch +4 more
2010· Health Affairs336doi:10.1377/hlthaff.2010.0081

Community health workers are recognized in the Patient Protection and Affordable Care Act as important members of the health care workforce. The evidence shows that they can help improve health care access and outcomes; strengthen health care teams; and enhance quality of life for people in poor, underserved, and diverse communities. We trace how two states, Massachusetts and Minnesota, initiated comprehensive policies to foster far more utilization of community health workers and, in the case of Minnesota, to make their services reimbursable under Medicaid. We recommend that other states follow the lead of these states, further developing the workforce of community health workers, devising appropriate regulations and credentialing, and allowing the services of these workers to be reimbursed.

The Effects of Referential Questions on ESL Classroom Discourse
Cynthia A. Brock
1986· TESOL Quarterly258doi:10.2307/3586388

In their examination of ESL teachers' questions in the classroom, Long and Sato (1983) found that teachers ask significantly more display questions, which request information already known by the questioner, than referential questions. The main purpose of the study reported in this article was to determine if higher frequencies of referential questions have an effect on adult ESL classroom discourse. Four experienced ESL teachers and 24 non-native speakers (NNSs) participated. Two of the teachers were provided with training in incorporating referential questions into classroom activity; the other 2 were not provided with training. Each of the 4 teachers taught the same reading and vocabulary lesson to a group of 6 NNSs. The treatment-group teachers asked significantly more referential questions than did the control-group teachers. Student responses in the treatment-group classes were significantly longer and more syntactically complex and contained greater numbers of connective.

Exploring the offshore wind energy potential of Turkey based on multi-criteria site selection
Mehmet Argin, Volkan Yerci, Nuh Erdoğan, Sadik Kucuksari +1 more
2018· Energy Strategy Reviews122doi:10.1016/j.esr.2018.12.005

Wind energy is the leading form of non-hydro renewable energy source in terms of installed capacity in Turkey. It is among the most promising option for Turkey to decrease the energy dependence of external primary energy resources such as national gas and oil that diversifies the domestic share of energy sources in the national energy mix. However, offshore wind energy deployment has not gained satisfactory attention even though the country is surrounded by seas on three of its sides. Exploring Turkey's offshore wind power potential becomes an important task to serve this energy policy. This study presents a methodological framework for finding the most suitable offshore wind farm locations, meeting various multi-layer site selection criteria. The offshore wind energy resource is first assessed using the wind energy potential for 55 coastal regions where the nearshore meteorological stations are available in Turkey. Following on this analysis, a multi-criteria site selection work is carried out to identify the most suitable areas for offshore wind development. Wind Atlas Analysis and Application Program (WAsP) is then used to conduct statistical analysis to identify the most promising offshore wind farm locations. According to the pre-processing step of the framework, Bozcaada, Bandirma, Gokceada, Inebolu, and Samandag coastlines are found to be the most suitable locations for offshore wind farm development. Finally, the offshore wind energy potential of Turkey is estimated by using the micro-sitting configuration of wind turbines, considering sea depth, main wind direction, and distance to shore for the most feasible project locations. It is found that total estimated offshore wind power capacity at the specified sites is 1,629 MW.

One college’s use of an open psychology textbook
John Hilton, Carol Laman
2012· Open Learning The Journal of Open Distance and e-Learning116doi:10.1080/02680513.2012.716657

The high cost of textbooks is of concern not only to college students but also to society as a whole. Open textbooks promise the same educational benefits as traditional textbooks; however, their efficacy remains largely untested. We report on a case study about one community college’s adoption of a free online psychology textbook. During the fall semester 2011, 690 students used this book. Compared with students using a traditional text in the spring of 2011, students who used the free online textbook scored higher on departmental final examinations, had higher grade point averages in the class and had higher retention rates.

Patient perspectives on how physicians communicate diagnostic uncertainty: An experimental vignette study†
Viraj Bhise, Ashley N. D. Meyer, Shailaja Menon, Geeta Singhal +3 more
2017· International Journal for Quality in Health Care100doi:10.1093/intqhc/mzx170

OBJECTIVE: We evaluated the effects of three different strategies for communicating diagnostic uncertainty on patient perceptions of physician competence and visit satisfaction. DESIGN/SETTING: Experimental vignette-based study design involving pediatric cases presented to a convenience sample of parents living in a large US city. PARTICIPANTS/INTERVENTION(S): Three vignettes were developed, each describing one of three different ways physicians communicated diagnostic uncertainty to parents-(i) explicit expression of uncertainty ('not sure' about diagnosis), (ii) implicit expression of uncertainty using broad differential diagnoses and (iii) implicit expression of uncertainty using 'most likely' diagnoses. Participants were randomly assigned to one of the three vignettes and then answered a 37-item web-based questionnaire. MAIN OUTCOME MEASURE(S): Outcome variables included parent-perceived technical competence of physician, trust and confidence, visit satisfaction and adherence to physician instructions. Differences between the three groups were compared using analysis of variance, followed by individual post hoc analyses with Bonferroni correction. RESULTS: Seventy-one participants completed the vignette questions. Demographic characteristics and scores on activation (parent activation measure [PAM]) and intolerance to uncertainty were similar across the three groups. Explicit expression of uncertainty was associated with lower perceived technical competence, less trust and confidence, and lower patient adherence as compared to the two groups with implicit communication. These latter two groups had comparable outcomes. CONCLUSION: Parents may react less negatively in terms of perceived competence, physician confidence and trust, and intention to adhere when diagnostic uncertainty is communicated using implicit strategies, such as using broad differential diagnoses or most likely diagnoses. Evidence-based strategies to communicate diagnostic uncertainty to patients need further development.

Learning From Patients’ Experiences Related To Diagnostic Errors Is Essential For Progress In Patient Safety
Traber Davis Giardina, Helen Haskell, Shailaja Menon, Julia Hallisy +4 more
2018· Health Affairs96doi:10.1377/hlthaff.2018.0698

Diagnostic error research has largely focused on individual clinicians' decision making and system design, while overlooking information from patients. We analyzed a unique new data source of patient- and family-reported error narratives to explore factors that contribute to diagnostic errors. From reports of adverse medical events submitted in the period January 2010-February 2016, we identified 184 unique patient narratives of diagnostic error. Problems related to patient-physician interactions emerged as major contributors. Our analysis identified 224 instances of behavioral and interpersonal factors that reflected unprofessional clinician behavior, including ignoring patients' knowledge, disrespecting patients, failing to communicate, and manipulation or deception. Patients' perspectives can lead to a more comprehensive understanding of why diagnostic errors occur and help develop strategies for mitigation. Health systems should develop and implement formal programs to collect patients' experiences with the diagnostic process and use these data to promote an organizational culture that strives to reduce harm from diagnostic error.

Accelerated hydrolytic degradation of ester-containing biobased epoxy resins
Minjie Shen, Rawan Almallahi, Zeshan Rizvi, Eliud Gonzalez-Martinez +2 more
2019· Polymer Chemistry79doi:10.1039/c9py00240e

Biobased epoxy resins, derived from lignin, phenolic acids, and vegetable oils, exhibited rapid degradation through hydrolysis in basic solution.

A review of wearable technology in healthcare: Monitoring patient health and enhancing outcomes
Ehizogie Paul Adeghe, Chioma Anthonia Okolo, Olumuyiwa Tolulope Ojeyinka
2024· Open Access Research Journal of Multidisciplinary Studies78doi:10.53022/oarjms.2024.7.1.0019

Wearable technology has emerged as a transformative force in the healthcare landscape, reshaping the way patient health is monitored and healthcare outcomes are enhanced. The paper delves into various types of wearables, including fitness trackers, smartwatches, and medical wearables, elucidating their functionalities and applications in the healthcare domain. The review emphasizes the profound influence of wearable technology on patient monitoring, encompassing continuous health tracking, remote patient monitoring, and chronic disease management. Through real-time data collection and analysis, wearables enable early detection of health abnormalities and empower healthcare providers to offer timely interventions, thereby reducing hospital readmissions. The role of wearables in chronic disease management is examined, showcasing their potential in tailoring personalized treatment plans and facilitating proactive health management. Furthermore, the paper explores the broader implications of wearable technology in enhancing healthcare outcomes. Wearables contribute to improved patient engagement by providing individuals with access to their health data, fostering a sense of empowerment and accountability. The review underscores the shift towards personalized healthcare, where wearables play a pivotal role in tailoring treatment plans based on individual health data and leveraging predictive analytics for disease prevention. Despite the promising advancements, challenges such as data security, privacy concerns, and integration with existing healthcare systems are discussed. Strategies to address these challenges and enhance user adoption and adherence to wearable technology are explored, recognizing the importance of a holistic approach in realizing the full potential of wearables in healthcare. This review serves as a comprehensive guide for researchers, healthcare providers, and policymakers, offering insights into the evolving landscape of wearable technology and its profound impact on monitoring patient health and improving healthcare outcomes.

Substance Use and Intimate Partner Violence Victimization Among White, African American, and Latina Women
Kathryn M. Nowotny, Jennifer L. Graves
2013· Journal of Interpersonal Violence78doi:10.1177/0886260513496903

The existing literature on intimate partner violence (IPV) does not paint a consistent portrait of the impact of race/ethnicity. In addition, although research has clearly demonstrated that there is a relationship between substance use and IPV, the temporal ordering of these variables is not clearly established. This article seeks to examine the temporal ordering of IPV victimization and drug use using longitudinal data with a nationally representative racially and ethnically diverse sample. Data from Wave III (2001-2002) and Wave IV (2007-2008) of the National Longitudinal Study of Adolescent Health (Add Health) will serve as Time 1 and Time 2, respectively, to answer three research questions. First, does substance use during early young adulthood (Time 1) predict IPV victimization during young adulthood (Time 2) among women? Second, does IPV victimization during early young adulthood predict substance use during young adulthood for women? Finally, do these bidirectional relationships vary by race/ethnicity (i.e., White, African American, and Latina)? Four different forms of IPV (minor violence, major violence, rape/sexual coercion, and injury) are investigated along with binge drinking, marijuana use, and other drug use. Understanding not only the temporal relationship between substance use, trauma, and IPV but also the racial and ethnic differences in these relationships is critical to developing and refining culturally sensitive trauma-informed prevention and treatment services for women.

A review of emerging trends in telemedicine: Healthcare delivery transformations
Ehizogie Paul Adeghe, Chioma Anthonia Okolo, Olumuyiwa Tolulope Ojeyinka
2024· International Journal of Life Science Research Archive68doi:10.53771/ijlsra.2024.6.1.0040

Telemedicine, characterized by the remote delivery of healthcare services using technology, has undergone remarkable transformations in recent years. This review explores the emerging trends in telemedicine and their profound impact on healthcare delivery. The paper begins by providing a background on telemedicine, tracing its evolution, and emphasizing its growing significance in the healthcare landscape. The primary objective is to shed light on the current state of telemedicine, identify key trends, and analyze their transformative effects on healthcare delivery. The technological landscape of telemedicine is examined, focusing on innovations in video conferencing, virtual consultations, and the integration of electronic health records. Furthermore, the role of artificial intelligence (AI) is explored, encompassing diagnostic assistance through medical imaging algorithms and the integration of chatbots and virtual health assistants. Specialized areas of telemedicine, such as mental health services and chronic disease management, are discussed in detail to highlight specific transformations in these domains. The critical aspect of patient and healthcare provider adoption is scrutinized, emphasizing patient engagement, overcoming technological barriers, and addressing the challenges faced by healthcare professionals in virtual settings. Anticipating the future of telemedicine, the review outlines upcoming innovations such as virtual reality applications and the impact of 5G technology. Simultaneously, it addresses persisting challenges, including health inequalities, ensuring quality of care, and ethical considerations. This review synthesizes the current state of telemedicine, identifies transformative trends, and provides insights into the future of healthcare delivery. It calls for continued research, policy development, and strategic implementation to maximize the potential of telemedicine in creating a more accessible, efficient, and patient-centric healthcare system.

Language specificity in the relation of maternal education to bilingual children’s vocabulary growth.
Erika Hoff, Andrea Burridge, Krystal M. Ribot, David Giguere
2017· Developmental Psychology68doi:10.1037/dev0000492

The robust relation between maternal education and child language that is observed in monolingual populations has not been reliably replicated among bilingual children from immigrant families in the United States. We hypothesized that a variable that operates in immigrant populations-the language in which mothers achieved their highest level of education, is relevant to the benefits of maternal education to children's language growth. The participants were 92 U.S.-born bilingually developing children (47 boys, 45 girls) with native Spanish-speaking immigrant mothers. The mothers varied both in their level of education and in the language (English or Spanish) in which they had achieved their highest level of education. The children's expressive vocabulary in English and Spanish was assessed at 6-month intervals between 30 and 60 months. Four sets of multilevel models, which included estimates of children's relative amount of input in each language and mothers' age of arrival, found that maternal level of education in English was significantly related to children's English skill, but not their Spanish skill, and that maternal level of education in Spanish was related to children's Spanish skill, but not their English skill. These language specific relations between mothers' levels of education and their children's language development potentially explain previous findings in immigrant populations. These findings further argue that maternal education benefits children's language because education changes mothers' use of the language in which that education was achieved. There was no evidence of a language general benefit of education, as might arise from increased knowledge of child development. (PsycINFO Database Record

Influence of dietary lipid upon ultraviolet‐light carcinogenesis
Homer S. Black, Wanda Lenger, A. Warner Phelps, John I. Thornby
1983· Nutrition and Cancer60doi:10.1080/01635588309513780

Dietary fats are known to influence the rate of formation of certain types of chemically-induced and spontaneous tumors. An earlier report indicated dietary fat also plays an important role in predisposition to ultraviolet light (UV)-carcinogenesis. Thus, an examination of the effects of dietary lipid level, degree of saturation, and antioxidant supplements on UV-carcinogenesis was undertaken. Twelve groups of 42 animals each received a restricted, semipurified, isocaloric diet containing 4%, 12%, or 12% (60% hydrogenated) corn oil with or without antioxidants (2%, w/w). A regimen of escalating UV irradiation was employed until an accumulative dose of 142 J/cm2 had been delivered. Animals were evaluated weekly for actinic lesions and biweekly for body weights, hematocrits, and serum triglyceride levels. A cumulative distribution function of time to tumor formation was estimated for all irradiated groups from which tumor development time in 50% (TDT50) of the population was derived. Although there were no significant differences in TDT50's between animals receiving low and high unsaturated lipid dietary regimens, animals receiving hydrogenated corn oil demonstrated a significantly (P less than 0.01) greater TDT50. Further, animals receiving hydrogenated 12% corn oil demonstrated fewer tumors per animal than those receiving either level of unsaturated corn oil. Antioxidants had no effect on TDT50's within any of the dietary groups. However, in regard to number of tumors per animal, greater tumor multiplicity was observed in groups receiving unsaturated lipid and antioxidants. These data demonstrate that the degree of dietary lipid saturation modifies the carcinogenic response to UV and, in conjunction with an earlier report, suggest that dietary lipid may modify the previously reported inhibitory effect of antioxidants on UV carcinogenesis. It may be concluded that adherence to dietary standards is as important as other experimental parameters when comparisons of UV effects are involved.

Resonant energy transfer enhances solar thermal desalination
Alessandro Alabastri, Pratiksha D. Dongare, Oara Neumann, Jordin Metz +3 more
2020· Energy & Environmental Science55doi:10.1039/c9ee03256h

Water production from solar thermal desalination is limited by the energy consumption of phase change. Resonant heat exchange between matched saline feed and purified distillate flow rates enables optimized recovery of vaporization energy.

The relationship between attitudes toward science and science achievement
Linda J. Hough, Martha K. Piper
1982· Journal of Research in Science Teaching54doi:10.1002/tea.3660190105

Abstract This study investigated the relationship between elementary pupils' attitudes toward science and their science achievement. Residualized gain scores were used to analyze the data. By using residualized gain scores, the effects of individual differences can be minimized. In addition to controlling for these differences, residualized gain scores do not possess the measurement errors that are normally associated with simple change scores. The subjects of this study were 583 intermediate elementary pupils. The average class size was 21. A pretest‐posttest design was used. To insure consistency in the teaching of the lesson, each teacher was given an identical detailed science lesson that included all the instructions and materials needed for the activity. The pupils were pre‐ and posttested. The pupils' science achievement was assessed by a test, the “Hough Pupil Process Test.” It consisted of multiple choice and fill‐in questions. The attitude instrument, the “Hough Attitude Inventory,” was given to the elementary pupils involved in this study. It was field tested and found to discern attitudes. The instrument consisted of six statements to which the subjects responded by circling either yes, I don't know, or no. The analysis revealed that there was a significant relationship between the pupils' residualized gain scores on the “Hough Pupil Process Test” and their residualized gain scores on the “Hough Attitude Inventory” (r = 0.45).

Impact of Androgen Deprivation Therapy on Racial/Ethnic Disparities in the Survival of Older Men Treated for Locoregional Prostate Cancer
Laurens Holmes, Wenyaw Chan, Zhi‐Dong Jiang, Doriel Ward +2 more
2009· Cancer Control48doi:10.1177/107327480901600210

BACKGROUND: Racial disparities persist in prostate cancer (CaP) treatment and survival, but disparities in androgen deprivation therapy (ADT) and the degree to which it affects racial differences in survival remains to be fully assessed. METHODS: Using the Surveillance, Epidemiology and End Results-Medicare linked data, we examined a large cohort of men (N = 64,475) diagnosed with locoregional CaP during 1992 to 1999 and followed through 2003. The effects of ADT and race on survival were analyzed using a Cox proportional hazards model. RESULTS: The receipt of ADT was significantly lower in African Americans (24%) relative to Caucasians (27%), Asians (34%), and Hispanics (28.7%) (P < .05). Compared with Caucasian race, African American race was associated with a statistically significant increased mortality (HR = 1.26, 95% CI = 1.21-1.32), which remained significant after adjusting for ADT but was substantially decreased after controlling for primary therapies such as radical prostatectomy, radiation, and watchful waiting (HR = 1.06, 95% CI = 1.01-1.10) and was no longer statistically significant after controlling for comorbidities (HR = 0.98, 95% CI = 0.94-1.03). CONCLUSIONS: There were marked racial variations in the receipt of ADT, primary therapies (namely surgery and surgery combined with radiation), and comorbidities. However, racial disparities in survival were not affected by racial variations in ADT but were explained by racial variations in primary therapies and by racial differences in comorbidities.

Predictors of Delayed HIV Diagnosis in a Recently Diagnosed Cohort
Jennifer K. Mayben, Jennifer R. Kramer, Michael A. Kallen, Luisa Franzini +2 more
2007· AIDS Patient Care and STDs46doi:10.1089/apc.2006.0097

Delayed diagnosis of HIV is associated with a worse prognosis despite highly active antiretroviral therapy. Many persons with HIV infection are diagnosed late in the disease process. We conducted a study of 119 persons recently diagnosed with HIV infection to determine the association of health literacy and other factors with delayed diagnosis. Patients were recruited from four publicly funded facilities in Houston, Texas. Health literacy was measured with the Test of Functional Health Literacy in Adults (TOFHLA). Delayed diagnosis was assessed by CD4 cell count at diagnosis. Sixty-five percent of patients had CD4 cell counts 350 cells/mm(3) or less. Twenty-eight percent had inadequate health literacy, but literacy was not associated with CD4 cell count. Thirty-eight percent were tested because they "felt sick." In multivariable analysis, female gender (p = 0.005), reason tested other than "felt sick" (p < 0.001), and marijuana use (p = 0.004) and other illicit drug use (p = 0.01) were predictors of having a higher CD4 cell count at diagnosis. These results confirm that late diagnosis of HIV is common among users of public health care facilities. Expanded routine testing for HIV infection is needed with attention directed to men and persons who may not recognize that they are at risk for contracting HIV infection.

Pancreatic ductal adenocarcinoma: the latest on diagnosis, molecular profiling, and systemic treatments
Doaa Bugazia, Ebtesam Al-Najjar, Abdullah Esmail, Saifudeen Abdelrahim +4 more
2024· Frontiers in Oncology45doi:10.3389/fonc.2024.1386699

Pancreatic ductal adenocarcinoma (PDAC) is currently the fourth leading cause of death in the United States and is expected to be ranked second in the next 10 years due to poor prognosis and a rising incidence. Distant metastatic PDAC is associated with the worst prognosis among the different phases of PDAC. The diagnostic options for PDAC are convenient and available for staging, tumor response evaluation, and management of resectable or borderline resectable PDAC. However, imaging is crucial in PDAC diagnosis, monitoring, resectability appraisal, and response evaluation. The advancement of medical technologies is evolving, hence the use of imaging in PDAC treatment options has grown as well as the utilization of ctDNA as a tumor marker. Treatment options for metastatic PDAC are minimal with the primary goal of therapy limited to symptom relief or palliation, especially in patients with low functional capacity at the point of diagnosis. Molecular profiling has shown promising potential solutions that would push the treatment boundaries for patients with PDAC. In this review, we will discuss the latest updates from evidence-based guidelines regarding diagnosis, therapy response evaluation, prognosis, and surveillance, as well as illustrating novel therapies that have been recently investigated for PDAC, in addition to discussing the molecular profiling advances in PDAC.

The Relationship between Faculty Diversity and Student Success in Public Community Colleges
James D. Cross, Carol A. Carman
2021· Community College Journal of Research and Practice41doi:10.1080/10668926.2021.1910595

Community colleges serve the most diverse student populations in higher education yet have some of the lowest levels of faculty diversity in higher education. Retaining community college student cohorts through transfer/graduation is a goal, yet attaining this goal has been elusive, particularly for underrepresented minority (URM) community college students. Few studies have explored the impact of faculty diversity on the successful retention of URM community college students. This study used archival data for 120 public community colleges from the Integrated Postsecondary Education Data System (IPEDS) to calculate a Diversity Score for each college and ranked them by their overall level of faculty racial/ethnic variance to quantify the relationship between faculty diversity and student graduation, transfer, and drop-out rates. The findings suggest that there is a significant strong positive relationship between graduation, transfer, and drop-out rates for URM students of all race/ethnic categories when there are increases in faculty diversity. Exposure to a diverse faculty produces different outcomes in URM students.

PERCEPTIONS OF AND RISK FACTORS FOR ANDROPAUSE
R. Tan, P.S. Philip
1999· Archives of Andrology39doi:10.1080/014850199262599

There has been some controversy about whether males undergo an andropause (male equivalent of a menopause). This study seeks to describe how older males perceive and understand this entity and whether there is an association between the age of onset of andropause and risk factors such as ethnic origin, smoking, alcohol, hypertension, and cerebrovascular disease. A nonexperimental, cross-sectional study was conducted at the outpatient clinic at a Veterans Affairs Medical Center. Subjects were interviewed by a single investigator and administered a questionnaire consisting of 22 items, including information on patient demographics, patient understanding of the andropause, patient understanding of possible interventions with hormonal therapy, medical, and drug history, and social habits such as smoking and drinking. Altogether 302 male patients were recruited, 71% of which were above the age of 60 years, and 87% were white, 6% were Hispanic, and 5% were black. The knowledge of patients toward the entity of andropause was lacking, though the majority (70%) expressed an interest in getting further knowledge. The most frequent age of onset of symptoms related to andropause was 51-60 years, and patients reported symptoms such as impotence, weakness, and memory loss. The next most common age reported to he associated with age of onset was 61-70 years. Multivariate regression analysis reveals that smoking more than 10 cigarettes a day was independently associated with an earlier onset of symptoms of andropause, bringing down the age of onset to below 50 years (p = .01, OR = 2.5, CI = 1.2-5.3). We found no association with risk factors such as ethnicity and alcohol. Andropause is experienced by many older males but knowledge of the entity is nonuniform. Older males are at risk for an earlier onset of andropause if they were smokers. This is the first study looking at risk factors for andropause and the results are consistent with studies in females on smoking and menopause.

Expression of the functional cone phototransduction cascade in retinoblastoma.
Richard L. Hurwitz, Emil Bogenmann, R. L. Font, V Holcombe +1 more
1990· Journal of Clinical Investigation38doi:10.1172/jci114648

Retinoblastoma is a malignant intraocular tumor that primarily affects small children. These tumors are primitive neuroectodermal malignancies, however some of them show morphologic evidence of differentiation into photoreceptors. Phototransduction cascades are a series of biochemical reactions that convert a photon of light into a neural impulse in rods and cones. The components of these cascades are uniquely expressed in photoreceptors and, although functionally similar, distinct components of these cascades are expressed in rods and cones. Using HPLC anion exchange chromatography, Western blot analysis, and specific monoclonal and polyclonal antibodies, we found that the cone but not the rod cGMP phosphodiesterase is functionally expressed in all six primary retinoblastomas examined and in three continuous retinoblastoma cell lines. Morphologic evidence of differentiation did not correlate with the expression of the enzyme. Furthermore, GTP analogues could activate the phosphodiesterase activity suggesting that an intact phototransduction cascade is present in the tumors. The presence of the cone phototransduction cascade in retinoblastoma confirms that this tumor has biochemically differentiated along the cone cell lineage.