Biomedical subjects
Publications and source records attributed to B Rosen.
Non-isotopic whole-mount in situ hybridization of mRNA is a novel technique that has greatly facilitated the precise three-dimensional localization of transcripts from genes whose expression is important during development. This methodology has recently been applied to the study of the mouse embryo and offers particular advantages over conventional procedures.
Intrastriatal injection of malonate, a reversible inhibitor of succinate dehydrogenase (SDH), produced age-dependent striatal lesions, which were significantly greater in 4- and 12-month-old animals than in 1-month-old animals. Both histologic and neurochemical studies showed that the lesions were significantly attenuated by administration of the noncompetitive NMDA receptor antagonist MK-801. Water-suppressed chemical shift magnetic resonance imaging showed that malonate produces increased striatal lactate concentrations and striatal lesions on T2-weighted scans that were attenuated by MK-801. Neurochemical characterization of the lesions showed significant decreases in markers of medium-sized spiny neurons (GABA and substance P), whereas a marker of medium-sized aspiny neurons (somatostatin) was not different from control values, consistent with an NMDA receptor-mediated mechanism. The effects of intrastriatal injections of malonate on ATP concentrations were compared with those of the irreversible SDH inhibitor 3-nitropropionic acid (3-NP). The ATP depletions following an equimolar injection of malonate were less marked and more transient than those of 3-NP. These results show that the competitive SDH inhibitor malonate produces more transient and milder bioenergetic defects than 3-NP, which are associated with selective activation of NMDA receptors. The results strengthen the possibility that a subtle impairment of energy metabolism may play a role in the pathogenesis of Huntington's disease.
Clinical observations have long suggested that skin perfusion (SP), among other factors, depends on thyroid status. However, quantitative data concerning this relationship are rather sparse. This study characterizes SP by means of laser Doppler flowmetry (LDF) in various thyroid dysfunctional states. The data reveal that mean capillary flow velocity, capillary pulse wave amplitude, and capillary flow oscillation amplitude, but not capillary flow oscillation frequency, are increased in hyperthyroid patients and decreased in hypothyroid patients. Regaining the euthyroid state is accompanied by normalization of LDF parameters only in hyperthyroid patients. It is concluded that LDF is useful in monitoring the thyroid effect on SP. However, it may not be used as a biological marker for the thyroid status of a given individual.
The association of menstrual dysfunction of athletes with changes in body composition has been controversial, because most estimations of body fatness have been indirect. Using magnetic resonance imaging, we quantified the sc and internal fat over a specific volume from the fifth thoracic vertebra to femoral fat in the upper thigh and at 4 other anatomical landmarks of 17 athletes (13 oarswomen and 4 runners) compared to that in 11 nonathletic controls. The magnetic resonance imaging data were also analyzed for the athletes and controls in relation to ovulatory status, which was determined by assay of urinary pregnanediol glucuronide, and in relation to the extent of 2-hydroxylation of estradiol to a nonpotent metabolite, 2-hydroxyestrone, which was evaluated by radiometric analysis. We found that 1) the relative and absolute body fat values of the athletes were significantly less (P < 0.05) than those of the controls overall and at each of the six regional sites, although the body weights of the rowers were significantly heavier than those of the controls, and the runners did not differ from the controls; 2) the ratio of sc fat to internal fat was 80%:20% among both athletes and controls, even though the athletes had significantly less fat; 3) the extent of estradiol 2-hydroxylation was significantly (P = 0.005) inversely related to total fat as a percentage of the total volume and to sc fat as a percentage of the total volume (P = 0.004) overall and at each of the regional fat depots; 4) athletes with menstrual disorders had significantly decreased sc and internal fat overall and at all regional sites compared to controls; and 5) a subgroup of ovulatory rowers had an apparent increase or lack of decrease in internal fat at the level of vertebrae lumbar 4, sacral 1, and sacral 4, compared to controls, whereas their sc fat was decreased at these sites compared to that in controls. Changes in regional fat deposits of both sc and internal fat may be involved in the menstrual dysfunction of the athletes in addition to their decreased overall fatness. The body weight and body mass index of well trained athletes can be a misleading index of body composition.
The latest wave of immigration, mostly from the former Soviet Union, has brought with it a large number of physicians. They are required to go through various stages of a licensing process in order to practice medicine in Israel. This overview describes the process, from arrival in Israel to the issuing of the license to practice medicine. From September 1989 to December 1991 some 9,800 of arriving immigrants identified themselves as physicians to Ministry of Absorption officials. However, only about 7,000 submitted requests for a medical license to the Ministry of Health. Physicians with at least 20 years of experience need not take an examination, but are required to work under supervision for 6 months in order to receive a license. Of those requesting a license, 1/3 had 20 years or more of professional experience, while the others had to take licensing examinations. By the end of December 1991, some 2,900 physicians had received licenses to practice medicine. This indicates that many immigrant physicians have yet to complete the licensing process.
OBJECTIVE: To investigate the possible role of position of the intrauterine device (IUD) in accidental pregnancies. METHODS: We examined the location of the IUD in 97 normal women 45-60 days post-insertion, and in 25 pregnant women with the device in situ. RESULTS: A cervically located IUD was identified in seven of 97 women (7.2%) after insertion and in 13 of 25 pregnant women (52%) with the device in situ. The odds ratio for a woman with an intracervical IUD to be pregnant compared with a woman with an IUD in the uterus was 13.93 (95% confidence limits 4.13-48.96). Sonographic follow-up of the pregnant women revealed no change in IUD location during early gestation. CONCLUSIONS: We suggest that cases of failed contraceptive action of the IUD may be secondary to a malpositioned device. A sonographic survey can identify displaced devices. Reinsertion of the IUD in such cases is recommended.
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Clinical observations suggest an age-associated decline in skin perfusion but there are few quantitative in vivo data on skin perfusion at various ages. We studied skin perfusion of the dorsum of the foot by determining the capillary blood flow velocity (CBFV) expressed in millivolts (mV), using laser Doppler flowmetry, in ten young and 12 elderly men. Our data revealed that, at 32 degrees C skin temperature, the CBFV oscillations (vasomotions) are of higher median amplitude in young people than in elderly subjects: 9.4 mV (95% CI, 8.8-10.0 mV) and 4.6 mV (95% CI, 4.1-7.4 mV), respectively (p less than 0.05). The vasomotion frequency was similar in both age groups. At 44 degrees C skin temperature, the median CBFV peak in the young was 163 mV (95% CI, 128-192 mV), as opposed to 102 mV (95% CI, 92-124 mV) in the aged subjects (p less than 0.0005). The median increment in CBFV, driven by every heart beat, was also higher in the young age group: 86 mV (95% CI, 76.4-96.0 mV) compared with the elderly group: 63 mV (95% CI, 50-72 mV, p less than 0.005). Considering the fact that the magnitude but not the pattern of skin perfusion varied between the two groups, we conclude that ageing is associated with loss of capillary plexus functional units, and therefore the skin perfusion is lower in aged people.
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We investigated expression of the adipose-specific serine protease adipsin in genetically obese Zucker rats and whether adrenalectomy modifies expression. Adipsin mRNA levels were determined by slot blot and Northern blot analysis of total RNA samples extracted from epididymal adipose tissue and isolated retroperitoneal adipocytes of obese (fa/fa) and homozygous lean (Fa/Fa) Zucker rats. Both 30-day-old and 4-mo-old animals were analyzed in experiment 1. In experiment 2, 10-wk-old obese and lean rats were either bilaterally adrenalectomized or sham operated, and adipsin mRNA levels were determined on tissue and cell samples 2 wk postsurgery. In both experiments, serum adipsin protein was determined by Western blot analysis and plasma insulin by radioimmunoassay. The data show that both adipsin mRNA and adipsin protein are reduced in obese compared with lean rats and that adrenalectomy restores these values toward normal in obese rats. The data thus suggest that adrenal steroids are involved in modulating adipsin expression in obese Zucker rats and that insulin may be an intermediary factor in such modulation.
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Between June 1984 and February 1988 the role of radiation with concurrent infusional 5-fluorouracil with or without mitomycin C (CT-RT) was examined in 33 patients with vulvar cancer. The median duration of follow-up is 16 months (range 5 to 45 months). Nine received adjuvant postsurgical CT-RT and none has relapsed in the radiation field. Seven are alive disease free. Two have died of distant metastases. Of the 9 receiving definitive primary CT-RT, 6 had initial complete response with subsequent vulvar relapse developing in 3. Seven of the 9 remain disease free after CT-RT alone (in 3) or with the addition of a local excision of residual or recurrent disease (in 6). One patient did not respond to CT-RT and required a radical vulvectomy and groin node dissection. Fifteen received CT-RT for disease recurrence following primary surgery. Disease was present in the vulva only in 11, vulva and inguinal nodes in 1 and nodes only in 3. Eight of the 15 had a complete response and no relapses occurred in the treated sites. Four of the 8 dying of disease developed pulmonary metastases. Serious late complications developed in 2 patients, 1 avascular hip necrosis and 1 proctitis requiring a defunctioning colostomy. CT-RT appears tolerable and may contribute to enhanced locoregional control in recurrent or advanced disease. As initial therapy it may allow lesser surgery with preservation of normal anatomy in selected primary vulvar cancers.
The decisions and actions of health care professionals have a major impact on such health care outcomes as cost, quality and equity. It is widely believed that professional behavior is determined, in part by how and how much they are paid. Professionals can respond to reimbursement incentives at both the individual level (treatment decisions, referral patterns, specialty choice, etc.) and at the level of the professional association. Health care analysts usually identify and discuss three principal reimbursement modes: salary, capitation, and fee-for-service. Mixed systems are proliferating and need to be evaluated. Payment levels are determined by a mix of equity, market, and political considerations. They are believed by many to influence the behavior of providers, who are thought to act so as to preserve target incomes. The target income hypothesis has been tested for the case of physicians operating in a fee-for-service environment. The impact of changes in reimbursement levels on the behavior of other groups of professionals and on the behavior of professionals working in other reimbursement modes remains unclear. Both policy-makers and researchers need to broaden the way in which they think about professional reimbursement. To date, the field has been dominated by economists, inquiry has focused heavily on physicians, and empirical work has emphasized those dimensions of outcome which are most easily measured. Changes in the organization of health services and in society-at-large intensify the need for a broader view.