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Biomedical subjects

J Weiner

Publications and source records attributed to J Weiner.

At least 19 recordsLinked to original sources
PubMed1998

Cyclic nucleotide-gated channels on the flagellum control Ca2+ entry into sperm.

Cyclic nucleotide-gated (CNG) channels are key elements of cGMP- and cAMP-signaling pathways in vertebrate photoreceptor cells and in olfactory sensory neurons, respectively. These channels form heterooligomeric complexes composed of at least two distinct subunits (alpha and beta). The alpha subunit of cone photoreceptors is also present in mammalian sperm. Here we identify one short and several long less abundant transcripts of beta subunits in testis. The alpha and beta subunits are expressed in a characteristic temporal and spatial pattern in sperm and precursor cells. In mature sperm, the alpha subunit is observed along the entire flagellum, whereas the short beta subunit is restricted to the principal piece of the flagellum. These findings suggest that different forms of CNG channels coexist in the flagellum. Confocal microscopy in conjunction with the Ca2+ indicator Fluo-3 shows that the CNG channels serve as a Ca2+ entry pathway that responds more sensitively to cGMP than to cAMP. Assuming that CNG channel subtypes differ in their Ca2+ permeability, dissimilar localization of alpha and beta subunits may give rise to a pattern of Ca2+ microdomains along the flagellum, thereby providing the structural basis for control of flagellar bending waves.

Amino Acid Sequence↗
PubMed1998

Intensive day program for psychiatrically disturbed truant adolescents.

Results of a day treatment program tailored to psychiatrically disturbed truant adolescents were compared to those of traditional outpatient treatment for effects on truancy, psychiatric symptoms, global improvement, and global functioning. Significantly greater reductions of truancy were found in the day treatment program, along with significantly greater improvement in the other factors measured.

Absenteeism↗
PubMed1998

Physician financial incentives and feedback: failure to increase cancer screening in Medicaid managed care.

OBJECTIVES: A randomized controlled trial evaluated the impact of feedback and financial incentives on physician compliance with cancer screening guidelines for women 50 years of age and older in a Medicaid health maintenance organization (HMO). METHODS: Half of 52 primary care sites received the intervention, which included written feedback and a financial bonus. Mammography, breast exam, colorectal screening, and Pap testing compliance rates were evaluated. RESULTS: From 1993 to 1995, screening rates doubled overall (from 24% to 50%), with no significant differences between intervention and control group sites. CONCLUSIONS: Financial incentives and feedback did not improve physician compliance with cancer screening guidelines in a Medicaid HMO.

Aged↗
PubMed1997

Confidentiality and health insurance fraud.

BACKGROUND: Health insurance fraud committed by patients may be an increasing problem given the number of underinsured and uninsured people in the United States. Physicians recognizing acts of health insurance fraud perpetrated by patients face an ethical dilemma: should they disclose the incident to the insurance company, or protect patient confidentiality? OBJECTIVE: To explore physicians' attitudes toward the reporting of patient-initiated health insurance fraud. METHODS: Three hundred seven physician members of the American College of Physicians returned a mailed questionnaire that presented 6 case vignettes (3 variables) of patients who used a relative's insurance to obtain health care in the past. For each vignette, respondents were asked whether the treating physician should report insurance fraud to the health insurance carrier. RESULTS: Sixty-three respondents (20.7%) indicated that physicians should report all the patients presented in the vignettes, while 45 (14.8%) indicated none should be reported; the rest indicated that the decisions to-report should be based on the characteristics presented, with acute vs terminal illness (P < .001), history of fraud (P < .001), and wealth of the patient (P < .001) all causing physicians to be more likely to report the patient to the health insurance carrier. Multivariate analysis demonstrated that type of practice (P = .04) and respondents' experiences with insurance fraud (P = .03) had significant effects on the willingness to report patients. CONCLUSIONS: Physicians are divided about whether to report patients who have committed insurance fraud. Their decisions to report insurance fraud are influenced by their attitudes and demographic features, as well as by patient factors.

Attitude of Health Personnel↗
PubMed1996

Telling patients about the diagnosis of HIV infection.

This study used a questionnaire to examine how patients in the HIV/AIDS Clinic at a Department of Veterans Affairs hospital were told of their diagnosis, by whom, and to what degree they were given emotional and educational support. Nearly 17% of patients were informed by someone not in the health professions (often military personnel), and 27% of patients were notified in a nonprivate setting. Forty-seven percent indicated they received little or no educational support at the time of diagnosis, while 39% received little or no emotional support. Educational and emotional support for patients at the time of HIV diagnosis may be lacking.

Adult↗
PubMed1996

Individual differences and the reliability of 2F1-F2 distortion-product otoacoustic emissions: effects of time-of-day, stimulus variables, and gender.

Distortion product otoacoustic emissions (DPOAEs) measured from the ear canal can be a sensitive tool to detect changes in cochlear function over time. However, if multiple-measurement procedures are to be useful clinically, testing needs to be reliable and sources of variability within individuals should be known. Herein, the influence of time-of-day (TOD), stimulus frequency, stimulus sound pressure level (SPL), and gender were evaluated on 2f1-f2 DPOAE amplitude in 16 adult volunteers with normal hearing. The effects of oral temperature and resting-pulse rate were also assessed. This study demonstrated a TOD main effect, with a period approximating one cycle-per-day. The magnitude of this effect averaged less than one dB and was not dependent on stimulus (frequency or SPL) or participant variables (gender, oral temperature, or resting-pulse rate), nor was it synchronized to a particular point-in-time. Stimulus level and gender effects on DPOAEs across frequency were also observed. Using generalizability theory (GT), DP iso-level/frequency profiles (DPILFPs) were found to be reliable measures within-subjects over a contiguous 24-hour time period. Significant and reliable between-subject differences were also documented. This study demonstrates the influence of stimulus and participant variables, quantifies the within-subject reliability over a 24-hour time period, and confirms that significant and reliable between-subject differences exist on DPOAEs across frequency, SPL, and gender.

Acoustic Stimulation↗
PubMed1996

Patients' perceptions of food-induced asthma.

BACKGROUND: The influence of diet in asthma control remains unclear. However, there is likely to be a wide gap between patient perceptions and the probable actual role. Some 20-60% of people with asthma report food as a trigger factor while approximately 2.5% react to double-blind placebo-controlled challenges. The aim of this study was to determine: the frequency, type and sources of dietary advice being offered to patients, the prevalence of dietary modification, whether dietary changes were perceived to be of benefit and the type and sources of food/beverage reactions that people perceive they have experienced. METHOD: A self-administered 'food and asthma' questionnaire was developed and mailed to 156 consecutive Alfred Hospital Asthma and Allergy Clinic patients registered on a computer database. RESULTS: The completed questionnaire response rate was 86.5%. Dietary advice had been offered to 47% of respondents while 61% had tried to modify their diet. Dietary restriction was the most common dietary modification. Where dietary restriction had occurred 79% of respondents perceived that this had improved their asthma control. A doctor was the most common source of dietary advice. Seventy-three per cent reported that food induced asthma. CONCLUSION: We confirmed that patients with asthma perceived diet to be important in their asthma control and that dietary modification is common despite its lack of objective basis. The influence of diet and asthma requires more research, evaluation and clinical attention.

Adult↗
PubMed1995

Clinical staffing in staff- and group-model HMOs.

Analysts frequently have used health maintenance organization (HMO) staffing patterns as a yardstick for estimating national clinical workforce requirements. Based on a nationwide survey of fifty-four staff- and group-model HMOs, the largest sample yet used in an analysis of this type, this DataWatch examines physician-to-member ratios, the use of nonphysician providers, and HMOs' methods of estimating clinical staffing needs. Overall physician staffing ratios and primary care physician staffing ratios closely resemble those reported in previous studies, but they exhibit wide variability and are strongly correlated with HMO size. Although caution should be exercised when using HMO staffing ratios in projections of physician workforce requirements, the ratios described here support projections of a specialty physician surplus.

Data Collection↗
PubMed1994

Cloning and functional expression of a cyclic-nucleotide-gated channel from mammalian sperm.

Cyclic nucleotide-gated (CNG) channels serve as downstream targets of signalling pathways in vertebrate photoreceptor cells and olfactory sensory neurons (see ref. 1 for review). Ca2+ ions that enter through CNG channels intimately control these signalling pathways by regulating synthesis or hydrolysis of cyclic nucleotides, and by decreasing ligand sensitivity of CNG channels. Several lines of evidence suggest that cyclic nucleotides and Ca2+ play important roles in chemotaxis of invertebrate sperm and fertilization (see ref. 9 for review), whereas their mechanisms of action in vertebrate sperm are largely unknown. Here we report the cloning and functional expression of a novel CNG channel from bovine testis. The channel polypeptide was functionally localized in sperm, but is also specifically expressed in cone photoreceptor cells. These channels might be involved in chemotaxis of sperm by controlling Ca2+ entry through a cyclic-nucleotide signalling pathway.

Amino Acid Sequence↗
PubMed1994

Development of the Leeds Dependence Questionnaire (LDQ): a questionnaire to measure alcohol and opiate dependence in the context of a treatment evaluation package.

The Leeds Dependence Questionnaire (LDQ) has been developed as part of a treatment evaluation package. The LDQ is a 10-item, self completion questionnaire designed to measure dependence upon a variety of substances; it has been shown to be understood by users of alcohol and opiates. The questionnaire was designed to be sensitive to change over time and to be sensitive through the range from mild to severe dependence; the follow-up data are insufficient to demonstrate change over time, but are encouraging. It is expected that both clinicians and researchers will find it useful to have a single measure relating to substance use, but not limited by specific substances. All items are scored 0-1-2-3; there are no normative data. The procedure for establishing content validity is described and estimates of concurrent, discriminant and convergent validities are reported; these validities are thought to be satisfactory. A principal components analysis produced a single factor accounting for 64% of the variance. Cronbach's alpha was 0.94. Test-retest reliability was found to be 0.95.

Adult↗