Hypotension and thirst in rats after isoproterenol treatment

Drinking induced in rats by systemic isoproterenol treatment is markedly attenuated after bilateral nephrectomy. The present experiments demonstrate that the hypotension produced by iso-proterenol treatment was more profound, and lasted much longer, in nephrectomized rats than in intact animals. When arterial blood pressure was partially elevated by central administration of angiotensin II or carbachol (Experiment 1) or by intraarterial infusion of epinephrine (Experiment 2), drinking behavior was restored in the nephrectomized animals and their water intakes approximated the amounts consumed by intact rats given isoproterenol. In general, an inverted U-shaped curve was found to define the relation between blood pressure and water intake in rats after isoproterenol treatment. Drinking was most probable when mean arterial blood pressures were in the range of 70–85 mm Hg, whereas rats were unlikely to drink when blood pressures were much below or above this range. These findings indicate that isoproterenol-induced thirst is not dependent on a renal dipsogen, and suggest instead that the hypersecretion of renin that occurs in intact rats is simply permissive of drinking behavior by modulating the hypotensive effects of the drug treatment.     

Efficacy response of inhaled beclomethasone dipropionate in asthma is proportional to dose and is improved by formulation with a new propellant

BACKGROUND: This study tested the hypothesis that there would be improved asthma control with increasing doses of beclomethasone dipropionate (BDP) formulated in hydrofluoroalkane-134a (HFA-BDP) and the standard chlorofluorocarbon propellants (CFC-BDP). Because HFA-BDP has improved lung deposition compared with CFC-BDP, this study also tested the hypothesis that HFA-BDP would provide more effective control of asthma than CFC-BDP. METHODS: In this multicenter, randomized, parallel-group blinded study, asthmatic subjects who had deterioration in asthma control after discontinuation of inhaled corticosteroids were randomized to receive one of 6 possible treatments: 100 microg/d, 400 microg/d, or 800 microg/d of HFA-BDP or 100 microg/d, 400 microg/d, or 800 microg/d of CFC-BDP for 6 weeks. Changes in spirometry, daytime asthma symptom and nighttime asthma-related sleep disturbance scores, morning and evening peak expiratory flows, and daily use of inhaled beta-agonist for symptom control on diary cards were assessed over 6 weeks of treatment. RESULTS: Three hundred twenty-three patients were randomized to the 6 treatment groups, which had similar demographics and baseline lung function. There were significantly larger changes from baseline at week 6 in FEV(1) percent predicted with increasing doses of both HFA-BDP and CFC-BDP. The FEV(1) percent predicted dose-response curve for HFA-BDP was shifted to the left compared with the dose-response curve for CFC-BDP. By using the Finney bioassay method, it was calculated that 2.6 times as much CFC-BDP would be required to achieve the same improvement in FEV(1) percent predicted as HFA-BDP (95% confidence interval, 1.1-11.6). All treatment groups except the 100 microg/d CFC-BDP group tolerated study drug well. Ten (17%) of 59 patients in this group reported an acute asthma episode, increased asthma symptoms (6 of the 8 reports of increased asthma symptoms were classified as severe), or both, and 8 patients withdrew from the study (3 for adverse events related to asthma). CONCLUSIONS: Increasing doses of inhaled corticosteroids lead to improved lung function and asthma control. Moreover, the reformulation of BDP in HFA enables effective asthma control at much lower doses than CFC-BDP.     

Controls of vasopressin secretion and thirst: similarities and dissimilarities in signals

RATS HAVE TWO PROMINENT RESPONSES TO DEHYDRATION: secretion of the antidiuretic hormone, vasopressin (VP), and thirst. Many signals directly affect both responses. These include two excitatory signals associated with increased plasma osmolality (pOsm) and two inhibitory signals associated with decreased pOsm (one each from cerebral and visceral osmoreceptors). In addition, both VP secretion and thirst during hypovolemia are stimulated by at least two signals, one neural (from cardiac baroreceptors) and one humoral (i.e., angiotensin II). In contrast to these evident similarities, there are definite dissimilarities in the signals for VP secretion and thirst. For example, acute hypervolemia inhibits VP secretion but not thirst, whereas acute hypertension inhibits thirst but not VP secretion. Thirst and VP secretion in rats each are stimulated by acute arterial hypotension, albeit not by the same signals; water intake is mediated by activation of the renin-angiotensin system but not by a neural signal from arterial baroreceptors, whereas the reverse may be true for the stimulation of VP secretion. These dissimilarities indicate that VP secretion and thirst in rats are neither invariably linked nor controlled by the same mechanisms.     

Surgery of labio-maxillo-palatal clefts during humanitarian mission in the Philippines

After describing the Philippines and the Comité de Soutien Enfance Philippines, a humanitarian association with a three-fold objective: to build, to educate and to treat, the authors present the organization and practical conduct of their missions abroad which have enabled them to treat almost 400 patients with cleft lip and palate between the ages of 3 months and 46 years.     

Mental health quality assurance. Development of the American Psychological Association/CHAMPUS program

In this article, quality assurance efforts in the field of mental health are discussed, especially concerning the reviews of outpatient clinical services. The recently established American Psychological Association APA/CHAMPUS program is described in detail, a national program of peer review that is illustrative of the major conceptual and professional issues inherent in the mental health quality assurance process. Throughout the article, comparisons are made between quality assurance in the medicine and mental health fields.     

Treatment of localized prostate cancer using a combination of high dose rate Iridium‐192 brachytherapy and external beam irradiation: Initial Australian experience

Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate‐ and high‐risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate‐specific antigen progression‐free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.     

A nationwide cohort study on Creutzfeldt-Jakob disease among human growth hormone recipients

OBJECTIVE: In 1991, a Dutch patient who had been treated from 1963 to 1969 with human-derived growth hormone died of Creutzfeldt-Jakob disease (CJD). This study was performed to investigate whether among other Dutch human growth hormone recipients there were clinically suspected cases of iatrogenic CJD. METHODS: In a retrospective cohort study, all patients (n = 564) treated with human-derived growth hormone before May 1985 and recorded in the Dutch National Growth Registry were followed up until January 1995 for a clinical diagnosis of CJD. For this purpose, all human growth hormone recipients were linked to a database of the Foundation for Health Care Information comprising hospital discharges with a clinical diagnosis of iatrogenic CJD. Linkage of the two databases was performed on the basis of date of birth and gender. Subsequently, verification of patient's name and initials of the positively matched pairs took place. RESULTS: Linkage provided 37 positively matched pairs concerning 29 individual patients. After verification, no name from the hospital discharge records corresponded to the names of the human growth hormone recipients. CONCLUSIONS The follow-up of 564 Dutch human growth hormone recipients, who had been treated with human growth hormone until 1985 did not establish any clinically suspected case of iatrogenic CJD. Future cases, however, can still emerge due to the potentially long incubation period of prion diseases.