Nitric oxide synthase and background adaptation in Xenopus laevis

Adaptation of the skin colour to the background light condition in the amphibian Xenopus laevis is achieved by migration of pigment granules in the skin melanophores, a process regulated by α-MSH secretion from melanotrope cells in the pituitary pars intermedia (PI). α-MSH secretion in turn, is regulated by various stimulatory and inhibitory messengers synthesized in brain nuclei, especially the hypothalamic suprachiasmatic and magnocellular nuclei and the locus coeruleus in the hindbrain.In the present study, the roles in background adaptation of nitric oxide (NO) and NO synthase (NOS) enzyme activity were evaluated. In situ, using both immunohistochemistry with anti-human brain NOS (bNOS) serum in paraffin-embedded material and using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry in cryo-sections, we showed NOS in neurons in the optic tectum and in the locus coeruleus. NADPH-d reactivity was also found in neurons in the lateral amygdala, the ventral hypothalamic nucleus and in fibers in the median eminence. Using a Western blot stained with an anti-human bNOS serum, we demonstrated a 150 kDa band in Xenopus hindbrain lysates, which is similar to the NOS protein present in the rat anterior pituitary, but which was not detectable in the lysates from both the neurointermediate and distal lobes in Xenopus. No differences in histochemical staining pattern or on Western blotting were observed between animals adapted to a black or a white background.Paraffin sections of the endocrine PI and pars distalis did not reveal bNOS-like immunoreactivity. NADPH-d reactivity was observed in the endothelia of this gland. However, using a new procedure of thin cryo-sections of pituitary neurointermediate lobes, we observed bNOS-immunoreactive fibers as well as cyclic 3′,5′ guanosine monophosphate (cGMP)-accumulating fibers in the PI.The PI may be regulated by NOergic neurons from higher brain centers. The possibility that NOergic neurons in the locus coeruleus are involved in the innervation of the PI needs further investigation. The latter neurons are probably not noradrenergic because double labeling studies show no co-localization of NADPH-d reactivity and tyrosine hydroxylase immunoreactivity in locus coeruleus neurons.     

Effect of voice rehabilitation on oral communication of Parkinson's disease patients

Voice and speech disorders are common in Parkinson's disease patients and may lead to social isolation. We employed routine clinical voice therapy measures to evaluate the effect of voice rehabilitation. Twenty patients with a stable drug regimen participated in this study. The patients were assessed before and after a program of voice rehabilitation consisting of 13 group therapy sessions during 1 month, with emphasis on the increase in laryngeal sphincteric activity. Voice rehabilitation produced an increase in maximal phonation times, decrease in the values of s/z ratio and air flow, increase in vocal intensity, decrease in the complaints of weak and strained-strangled voice and monotonous and unintelligible speech and elimination of complaints of swallowing alterations. These data indicate a greater glottic efficiency after voice rehabilitation reflecting a more functional oral communication.     

Population-based prevention of influenza in Dutch general practice.

BACKGROUND: Although the effectiveness of influenza vaccination in high-risk groups has been proven, vaccine coverage continues to be less than 50% in The Netherlands. To improve vaccination rates, data on the organizational factors, which should be targeted in population-based prevention of influenza, is essential. AIM: To assess the organizational factors in Dutch general practice, which were associated with the influenza vaccination rate in 1994. METHOD: A retrospective questionnaire study was undertaken in 1586 of the 4758 Dutch general practices, which were randomly selected. A total of 1251 (79%) practices returned a questionnaire. The items verified were practice profile, urbanization, delegation index, use of computer-based patient records, influenza vaccination characteristics and influenza vaccination rate. RESULTS: No differences were found with regard to the percentage of single-handed practices (65%), practices situated in urban area (38%), practices with a pharmacy (12%), patients insured by the National Health Service (59%) and use of computer-based patient records (57%) when compared with national statistics. The mean overall influenza vaccination rate was 9.0% (SD 4.0%). Using a logistic regression analysis, a high vaccination rate (> or = 9%) was associated with the use of personal reminders (odds ratio (OR) 1.7, 1.3-2.2), monitoring patient compliance (OR 1.8, 1.3-2.4), marking risk patients in computer-based patient records (OR 1.3, 1.0-1.6), a small number of patients per full-time practice assistant (OR 1.5, 1.1-1.9), urban areas (OR 1.6, 1.3-2.1) and single-handed practices (OR 1.5, 1.1-1.9). CONCLUSION: Improvement of vaccination rates in high-risk patients may be achievable by promoting the use of personal reminders and computer-based patient records, as well as monitoring patient compliance. In addition, the role of practice assistants with regard to preventive activities should be developed further. Practices situated in rural areas and group practices may need more support with a population-based approach for the prevention of influenza.     

Hospitals in sub-Saharan Africa: why we need more of what does not work as it should

This paper analyses the origins of today's crisis in the hospital sector in sub-Saharan Africa. Present trends in availability of hospital services are extrapolated to the future in order to provide a low-end estimate of the need for expansion of first referral level hospitals. This will not be possible without giving due priority to this sector, a commitment to considerable investments and reorientation of resources from tertiary to first referral level hospitals. It is to be feared that if this is not done, the backlog will increase, and, given the time lag before investments translate into operational services, there will be a major shortage of hospital services in sub-Saharan Africa within a decade.     

Enlarged adenomectomy for enclosed prolactinomas: A preliminary study of 26 cases

Summary Preliminary results obtained from 26 cases of prolactinomas less than 20 mm in diameter after treatment by enlarged adenomectomy are described.The operation consisted in removal of the adenoma, a layer of normal pituitary at the outer edge of the tumour and the pituitary capsule in contact with the sellar meninges. 24 women and 2 men were involved whose prolactin levels (PRL) were less than 200 ng/ ml. All presented abnormal PRL responses to Thyrotropin releasing hormone (TRH) and Metoclopramide (MCP) tests and an absence of a nocturnal rise in the sleep cycle study. Postoperatively, three patients developed transitory diabetes insipidus and five transitory adrenal insufficiency. Gonadotropin reserve was always found normal. All 24 women resumed normal menstrual cycles and two became pregnant within one year. From a serological viewpoint, after surgery 100% of patients were found to be normal for levels of prolactin but only 85% turned to normal dynamic tests. The results of this small series of enlarged adenomectomies seem better than those obtained using selective adenomectomy, but must be confirmed with time.     

Effects of postoperative pain on lung volume in patients undergoing aortic surgery

To evaluate the potential advantages of the administration of extradural morphine to control postoperative pain and its effects on respiratory function, 39 patients were randomly assigned to one of two groups before aortic surgery. The first group (20 patients) received intravenous analgesia as required (control group). The second group (19 patients) received extradural morphine in a programmed fashion. During the immediate postoperative period the following parameters were measured in both groups: respiratory rate, vital capacity, peak expiratory volume in the first second, PaO2, PaCO2, arterial pH, heart rate, and systolic and diastolic blood pressure. In the group treated with morphine the postoperative increase in heart and respiratory rate was significantly smaller than in the control group (p less than 0.01). Postoperative forced pulmonary volumes were higher in the morphine group (p less than 0.01). However, there were no differences in time of hospitalization between both groups. There were more complications in the control group, but the difference did not reach statistical significance.     

Bioequivalence of two pharmaceutical forms of diltiazem

Diltiazem, a calcium-channel blocking agent, has been shown to be a potent coronary vasodilator used in the treatment of ischaemic heart disease. The present study was conducted to compare the bioavailability of regular 60 mg tablets administered every 6 h with sustained release capsules of 120 mg administered every 12 h. High-performance liquid chromatographic analysis was carried out for determination of diltiazem and one of its metabolites desacetyldiltiazem in six male patients. The relative bioavailability of this sustained-release pharmaceutical form did not show any significant difference with that of tablets.