PubMed Health⌕ Search

Biomedical subjects

R Levin

Publications and source records attributed to R Levin.

At least 37 records · Page 2Linked to original sources

Neonatal outcome of preimplantation genetic diagnosis by polar body removal: the first 109 infants.

CONTEXT: Our center developed the technique of preimplantation genetic diagnosis (PGD) by sequential polar body removal (PBR) for the diagnosis of Mendelian disorders and aneuploidies. This study examines the obstetric and neonatal outcome of the first 109 live births after PGD by PBR. OBJECTIVE: To determine if there were any observable effects of PGD by PBR on perinatal morbidity and mortality, birth defects, and growth parameters. DESIGN: Data on perinatal outcome were gathered for the first 109 infants by parental reporting and confirmed by telephone interview and chart review when indicated. In infants >6 months old, a follow-up telephone interview was performed establishing the developmental milestones attained by the child. SETTING: A research center conducting an institutional review board-approved research protocol in PGD. PATIENTS: All patients who had PGD by PBR who had clinical pregnancies. MAIN OUTCOME MEASURES: Gestational age, mode of delivery, perinatal mortality, birth weight, birth length, the presence of birth defects, and developmental milestones. RESULTS: There was no significant decrease in birth length or weight, or the frequency of small for gestational age infants. No specific pattern of birth defects was observed. CONCLUSION: Thus far, there are no observable detrimental effects of PGD by PBR on children born after the procedure.

Aneuploidy↗

Hemoglobin/O2 systems: using short-lived intermediates for mechanistic discrimination.

The kinetics of the reaction of hemoglobin with molecular oxygen, in which rapid mixing is followed by a very fast temperature jump, is numerically simulated. Four different mechanisms are considered. In two of them, oxygen reacts with the alpha-chains first, in the other two with the beta-chains first. Furthermore, either the third or the fourth measured (Adair) dissociation constant is composed of the product of a local dissociation constant and an allosteric interconversion constant. We explore whether these alternative mechanisms may be distinguished experimentally. We show that reaction steps not resolvable by rapid mixing can be resolved by chemical relaxation at appropriate points in time. Discrimination under experimental conditions is possible at higher oxygen concentrations (above 100 microM), but high resolution in time and concentration amplitude are required.

Animals↗

Dreams of personality disordered subjects.

Dreams provide access to underlying personality structure, defensive and adaptive functions, and they elucidate the psychological forces that lead to overt symptomatic behavior. Two hundred three dreams of 39 personality disordered patients were factor analyzed and compared with Hall and Van de Castle's normative data (Hall C, Van de Castle RI [1966] The content analysis of dreams. New York: Appleton-Century-Crofts). Results included a five-factor solution that sheds light on some core issues of the dreamers. Comparisons between the groups resulted in the personality-disordered group demonstrating more estrangement in their dreams, fewer interactions, and more emotionality. In their interactions, they demonstrated a lower ratio of aggressive interactions yet a higher tendency to view themselves as the aggressor. Results are related to theoretical literature on personality and defensive styles, mostly from a psychodynamic perspective.

Aggression↗

Review of recent placebo-controlled trials utilizing phytotherapeutic agents for treatment of BPH.

BACKGROUND: In order to assess the efficacy of phytotherapeutic agents for the treatment of benign prostatic hyperplasia (BPH), a review of recently published double-blind placebo-controlled trials was undertaken. METHODS: Only those studies reviewed by the Other Medical Therapies Committee of the Fourth International Consultation on BPH were included. RESULTS: These studies suggest a possible benefit for the use of phytotherapeutic preparations in the treatment of BPH. CONCLUSIONS: These studies need to be confirmed in larger long-term placebo-controlled studies in order to ascertain the true efficacy of these agents.

Anti-Bacterial Agents↗

Apolipoprotein E epsilon 4 allele in association with global cognitive performance and CSF markers in Alzheimer's disease.

To better define the influence of apolipoprotein E (ApoE) epsilon 4 genotype on the cognitive and biochemical features of Alzheimer's disease (AD), cross-sectional analysis of global cognitive measures and cerebrospinal fluid studies gathered on AD subjects at a tertiary care facility between 1986 and 1997 was carried out. The 112 AD patients examined included 62 women and 50 men with a mean (SD) age of 64.2 (9.2) years. Patient demographics; illness onset age and duration, education level and global cognitive measures were recorded systematically. Genetic analysis for ApoE allele type and biochemical characterization of CSF, including total tau concentration, was performed. Descriptive statistics of demographics, cognitive and CSF measures were performed by chi-square, ANOVA and Tukey's tests. Overrepresentation of the epsilon 4 allele was found, with 45.5% of AD patients heterozygous and 20.5% homozygous for ApoE epsilon 4. Overall, ApoE epsilon 4 status had no effect on mean onset age of AD (F = 1.56; p = 0.214), but an earlier mean onset age of AD (F = 4.10; p = 0.02) was seen in the late-onset subjects. No differences were found with regard to ApoE epsilon 4 status and measures of disease, duration of illness or global cognitive performance. Although CSF tau was elevated in our sample (575.4 +/- 290.3 pg/ml), ApoE epsilon 4 status did not influence total CSF tau or neurotransmitter metabolite levels. ApoE epsilon 4 genotype had no impact on a variety of illness severity, cognitive and CSF examinations in the largest cross-sectional analysis of AD subjects yet reported.

Aged↗

Minimally invasive surgical treatment of female stress urinary incontinence.

The purpose of this study was to evaluate the safety and efficacy of a new minimally invasive surgical procedure for the treatment of female stress urinary incontinence (SUI). Four miniature bone anchors, each attached to a suture, are inserted transvaginally into the retropubic bone using an inserter on each side of the urethra without opening the vaginal mucosa. Tying the suture on each ipsilateral side creates colposuspension, as is the aim of previously described procedures such as the Marshall-Marchetti-Krantz. Sixty-one women (mean age 52+/-SD 9.9 years) with a mean follow-up of more than 12 months (range 12-30 months) were treated for SUI. Fifty patients (82%) are dry, 7 (14%) reported great improvement and 4 are considered surgical failures. The data presented suggest that our new minimally invasive procedure provides an effective treatment for female SUI. Its main advantages over other procedures are the transvaginal approach and short operating time.

Female↗

An experimental model of diabetes and cancer in rats.

The aim of this study was to develop an experimental model for the study of cancer associated with diabetes. For diabetes induction, Sprague-Dawley rats were given streptozotocin (STZ, 90 mg/kg body weight (BW), by intraperitoneal injection on the second day of life. For mammary tumour induction, rats were injected with 50 mg/kg BW of N-nitroso-N-methylurea (NMU) at 50, 80 and 110 days old. The neoplastic process and the effect of tamoxifen treatment was examined in non-diabetic and diabetic rats. The latency period, NMU-induced tumour incidence and the number of tumours per rat in diabetic rats versus controls were 117 +/- 7 days versus 79 +/- 9 days (P < 0.001); 93% versus 95% (NS); and 5.2 +/- 1.6 versus 2.7 +/- 0.5 (P < 0.02). A more benign histological pattern for tumours in diabetic animals was observed. Mammary tumours in diabetic rats grew more slowly than in controls. Tamoxifen (1 mg/kg/day) treated diabetic rats showed tumour regression in 67% of NMU-induced mammary tumours versus 53% in controls (NS). Our results show that tumour progression seems to be affected by diabetes in this experimental model. We suggest this is the result of changes to insulin-like growth factors and their receptors, which occur in diabetics, and our future research will examine this hypothesis.

Animals↗

Nightmares and schizotypy.

In order to explore the proposed relationship between nightmare occurrence and schizotypy, 30 frequent-nightmare subjects (at least one occurrence per week) and 30 low-nightmare controls, all of whom were female college students, were compared on several converging measures of schizotypal signs and behaviors. Consistent with previous research, frequent nightmare subjects demonstrated greater deviance on psychometric scales of schizotypy, and reported significantly greater schizotypal symptomatology on a structured clinical interview, than controls did. In addition, nightmare subjects produced similar electrodermal habituation patterns to auditory orienting stimuli as those that have been documented in schizophrenia-spectrum disorders. The results suggest that nightmare experience may be a useful conjoint behavioral indicator for the early detection of schizophrenia-spectrum psychopathology.

Acoustic Stimulation↗

Nightmares and psychotic decompensation: a case study.

There have been numerous reports in the literature on the descriptive similarities between a severe nightmare and an acute psychotic episode. Nightmares may be a prelude to psychotic decompensation, and it has been suggested that frequent lifelong nightmares may even be diagnostic of an underlying vulnerability to psychosis. In this report, we present a case study of a 40-year old female experiencing chronic paranoid schizophrenia, whose two witnessed psychotic relapses in the hospital were immediately preceded by intense and vivid nightmare attacks. Significantly, the content of these nocturnal dreams was thematically consistent with her waking hallucinations, suggesting a direct continuity between these experiences. We propose that further systematic study of the dreams and nightmares of individuals diagnosed with schizophrenia may be particularly useful in understanding their phenomenological experience.

Adult↗

Organizational, financial, and environmental factors influencing deans' tenure.

At a time when continuity of leadership in medical schools is most crucial, the tenures of deans continue to decrease. In the present study of factors influencing the tenures of 382 U.S. medical school deans from 1985 to 1994, the authors focused on issues that were likely to have had a greater impact on deans' tenures in recent years. They assumed that longer tenures are associated with less complex organizational factors and more stable environmental factors. Conversely, they assumed that deans and their tenures are adversely affected by an institution's declining financial health, a complex organizational structure, and a changing clinical marketplace where there is rapid growth of managed care. The authors compared the relationships between these factors and the length of deans' tenures during the ten-year period studied. Among the most important findings were the fact that schools that were less healthy financially, that had the same owner as the primary teaching hospital, and that had smaller numbers of faculty tended to have shorter dean's tenures and higher turnovers of deans. While the reason for shorter tenures of deans at schools that are less financially healthy is understandable, the effect of common ownership of the school and teaching hospital is less obvious, but perhaps the greater preoccupation of deans with the clinical enterprise in that circumstance is a significant constraint. The authors hope that the insights from their findings will be useful to future candidates for deanships in their negotiations with university officials and will help all parties reach more explicit agreements on such issues as expectations for financial performance of the medical school and the roles and relationships of the dean and the teaching hospital director.

Career Mobility↗

Patient noncompliance in the managed care setting. The case of medical therapy for glaucoma.

OBJECTIVES: The authors identify demographic and clinical characteristics associated with noncompliance in patients beginning medical therapy for the treatment of glaucoma in a managed care setting. METHODS: The authors describe a retrospective cohort study in a group-model health maintenance organization in Massachusetts. Patients were members of the health maintenance organization who were newly initiated on topical drug therapy to treat open-angle glaucoma during the period January 1, 1987 through December 31, 1990, who met eligibility requirements, and who had evidence of health services utilization for a 12-month follow-up period. For all study subjects, we determined the number of days without available therapy for glaucoma during the 12-month period. Study subjects who did not fill prescriptions adequate to provide medication to cover at least 80% of days during the study period were considered noncompliant. Logistic regression analysis was used to assess demographic and clinical factors independently associated with noncompliance among patients initiated on medical therapy for the treatment of glaucoma. RESULTS: Of 616 subjects who met inclusion criteria, 152 (24.7%; 95% confidence interval, 21.3%-28.1%) met the study definition for noncompliance. These patients had an average number of days without therapy during the 12-month study period of 103.9 +/- 70.0 days compared with 6.8 +/- 19.5 days for those categorized as compliant. Of a variety of selected demographic and clinical characteristics, having fewer visits with an ophthalmologist during the study period (< 2) was most strongly related to noncompliance (odds ratio 2.99; 95% confidence interval 2.03, 4.40). There were no differences in average intraocular pressure between the compliant and noncompliant groups during the study period. CONCLUSIONS: Noncompliance with prescribed medical therapy for glaucoma was found to be common in a managed care setting characterized by essentially unrestricted access to health care and medications. It remains difficult to identify noncompliant patients based on demographic and clinical characteristics. The use of automated prescription data to identify noncompliant patients is feasible in large managed health care insurance programs where such data are collected routinely for administrative purposes.

Adult↗

Health care utilization by children with chronic illnesses: a comparison of medicaid and employer-insured managed care.

OBJECTIVES: This study compared utilization of health care services by children with chronic conditions who were insured by either Medicaid or an employer group in 1992 and 1993. Five chronic conditions were selected to illustrate patterns of service use: asthma, attention deficit disorder, diabetes, epilepsy, and sickle cell anemia. METHODOLOGY: Administrative databases were used to develop estimates of health services utilization for children <18 years of age with the five selected conditions, who had been enrolled for at least 6 continuous months. All claims for a child identified with one of these five conditions were included in the analysis, including claims for diagnoses and procedures not directly related to the primary diagnosis. Estimates were derived for eight services (eg, hospital admissions, emergency department (ED), home health). Data were used from two Independent Practice Association model health plans in two states. Differences across the states were controlled by selecting one Medicaid and one employer-insured program from each of the two plans in both states. Regional variation was controlled for because both health plans were located in one geographical region. In each case, physicians were paid on a fee-for-service basis, with generally open access to specialists rather than primary care gatekeeper models of delivery: t tests were used to compare service use rates between Medicaid and employer-insured populations. RESULTS: A total of 8668 children across all health plan groups had at least one of the selected conditions. Because Medicaid enrolled-children tended to be younger, analyses were adjusted for age. In both systems, a greater percentage of Medicaid children had these five study conditions (5%) compared with employer-insured children (3%), suggesting that the Medicaid population was sicker. Mean length of enrollment during the 2-year study was longer for children in employer-insured programs. Children with chronic conditions enrolled in Medicaid managed care generally used services at a higher rate compared with children with similar conditions enrolled in employer-insured managed care. The extent of the increased use varied by condition, by service type, and by plan. Children with any of the chronic conditions studied had from 2 to almost 5 times more ED visits if they were enrolled in Medicaid than if they were enrolled in employer-based managed care, depending on the specific condition. In one of the two plans, Medicaid-enrolled children had more outpatient services, laboratory services, and radiography services than their counterparts in employer-based managed care. The same pattern of use was found for home health services (except for children with diabetes) and for office visits (except for children with sickle cell). The results show higher use of all services by children with asthma and diabetes in Medicaid managed care compared with employer-based managed care. In contrast, the pattern is mixed for children with epilepsy and sickle cell. The sample size of children with these conditions was smaller than with the three other conditions, which may account, in part, for a varied pattern of results. The pattern of use for attention deficit hyperactivity disorder (ADHD) was generally different from the other conditions. Children with ADHD in employer-based managed care had more hospital admissions, hospital days, and office visits than their counterparts in Medicaid managed care. In contrast, Medicaid-enrolled children with ADHD had more ED visits, laboratory services, outpatient hospital visits, and radiography services. Other than ED visits, the differences in service use between Medicaid and employer-insured children with ADHD were minimal. Of note, the pattern for ADHD is the same for most services for Plans A and B (excluding home health visits). This utilization pattern may reflect service use for comorbid conditions. Part of this difference may be explained by differences in Medicaid e

Adolescent↗

Is overhead bad?

Explore the source record for details and available documents.

Capital Expenditures↗