Primary care intervention and management for adults with early HIV infection.

Recent clinical drug trials have demonstrated that early intervention with zidovudine will delay disease progression in asymptomatic or minimally symptomatic HIV-infected individuals. These trials will encourage larger numbers of seropositive persons to seek access to primary care, overloading specialized clinics for AIDS and HIV care. The care of early HIV-infected individuals will need to be delivered by mainstream primary care providers. This article discusses the initiation and management of zidovudine, and chemoprophylaxis against Pneumocystis carinii pneumonia in early HIV infection.     

Object recognition by artificial cortical maps.

Object recognition is one of the most important functions of the human visual system, yet one of the least understood, this despite the fact that vision is certainly the most studied function of the brain. We understand relatively well how several processes in the cortical visual areas that support recognition capabilities take place, such as orientation discrimination and color constancy. This paper proposes a model of the development of object recognition capability, based on two main theoretical principles. The first is that recognition does not imply any sort of geometrical reconstruction, it is instead fully driven by the two dimensional view captured by the retina. The second assumption is that all the processing functions involved in recognition are not genetically determined or hardwired in neural circuits, but are the result of interactions between epigenetic influences and basic neural plasticity mechanisms. The model is organized in modules roughly related to the main visual biological areas, and is implemented mainly using the LISSOM architecture, a recent neural self-organizing map model that simulates the effects of intercortical lateral connections. This paper shows how recognition capabilities, similar to those found in brain ventral visual areas, can develop spontaneously by exposure to natural images in an artificial cortical model.     

The simultaneous occurrence of renal artery stenosis and an aldosteronoma in a patient with hypertension

The simultaneous occurrence of renovascular hypertension and an adrenocortical adenoma is a rare entity. The case of a 64-year-old woman who underwent an aortorenal bypass graft for renovascular hypertension requiring a multidrug antihypertensive regimen is presented. Persistently elevated blood pressures in the postoperative period prompted further workup for other causes of hypertension. Laboratory evaluation showed hyperaldosteronism and hyporeninemia despite enalapril administration. Abdominal computerized tomography (CT) revealed a left adrenal mass which, on surgical removal, was found to be a cortical adenoma. Subsequently, her antihypertensive therapy has been reduced to a single agent. Previous authors have described only four patients with malignant hypertension who had the rare clinical combination of renal artery stenosis and an aldosteronoma. This case reemphasizes the critical need for a thorough search for other surgically correctable lesions in those patients who remain severely hypertensive after the "definitive" operation.     

Psychoactive drug use among practicing physicians and medical students

We surveyed random samples of 500 practicing physicians and 504 medical students in a New England state during 1984-1985; 70 percent of the physicians and 79 percent of the students responded. Fifty-nine percent of the physicians and 78 percent of the students reported that they had used psychoactive drugs at some time in their lives. In both groups, recreational use most often involved marijuana and cocaine, and self-treatment most often involved tranquilizers and opiates. In the previous year, 25 percent of the physicians had treated themselves with a psychoactive drug, and 10 percent had used one recreationally. Although most of the use was experimental or infrequent, 10 percent of the physicians reported current regular drug use (once a month or more often) and 3 percent had histories of drug dependence. More physicians and medical students had used psychoactive drugs at some time than had comparable samples of pharmacists and pharmacy students. The results suggest a need for renewed professional education about the risks of drug misuse.     

Motor responses evoked by microstimulation of restiform body in the cat

Motor effects produced by microstimulation of restiform body (RB) were studied in acute unanesthetized cats, using tungsten electrodes for stimulating the peduncle and bipolar steel electrodes for recording muscular activity (EMG). The main results were the following. 1. Threshold microstimulation (18.24 microA +/- 8.77 S.D.) of effective foci within RB elicited single muscle contractions of ipsilateral limbs, primarily of forelimb; overthreshold activation (32.83 microA +/- 9.25S.D.) of the same points produced complex movements in 61.54% of cases that involved muscles of shoulder, neck, and trunk. 2. Single muscle contractions exhibited a mean latency (20.09 msec +/- 2.04 S.D.) which was significantly longer than that shown by complex movements (10.00 msec +/- 3.10 S.D.). Furthermore, a decrease in frequency of stimulating train below 300 Hz and a reduction in duration below 30 msec caused a steep rise of threshold for single muscle responses that was not observed when studying complex movements. 3. Acute RB interruption between stimulating electrode and cerebellum abolished single muscle contractions; conversely, complex movements remained unmodified even when the RB was lesioned in cats chronically submitted to interruption of brachium conjunctivum (BC). 4. The pathway involved in promoting RB induced single muscle activation includes interpositus nucleus, BC and rubrospinal tract. Possible modalities of RB afferent participation to the motor control are briefly discussed.     

Healthcare Workers’ (HCWs) attitudes towards mandatory influenza vaccination: A systematic review and meta-analysis

Influenza is a disease responsible for thousands of deaths every year. Although healthcare workers (HCWs) represent a way of contagion for patients, vaccination coverage among them is low. Mandatory vaccination has been proposed, but controversies remain. This systematic review and meta-analysis aimed to assess the acceptance of mandatory vaccination by HCWs, and to investigate associated characteristics. MEDLINE, Scopus, Embase, PsycInfo, CINAHL and Web of Science were used to search for studies assessing the topic. PRISMA statements were followed. Of the 13,457 univocal records found, 52 studies were included in the systematic review and 40 in the meta-analysis. The pooled proportion of HCWs accepting the policy was of 61% (95% CI: 53%- 68%) but with great heterogeneity between continents (from 54% in Europe to 69% in Asia) and in different professionals (from 40% in nurses to 80% in students). Vaccinated HCWs agreed more frequently with mandatory vaccination than non-vaccinated ones. More studies that consider mandatory vaccination acceptance as the main outcome are needed, but the results of this study confirm that in some settings the majority of HCWs favour mandatory vaccination. This, combined with effects that a flu epidemic could have if overlapped to pandemics with similar symptoms, requires renewed considerations on mandatory vaccination.     

Prevention by morphine of apomorphine- and oxytocin-induced penile erection and yawning: involvement of nitric oxide

The possible involvement of nitric oxide in the prevention by morphine of apomorphine- and oxytocin-induced penile erection and yawning was investigated by measuring the concentration of NO₂- and NO₃- in the dialysate obtained with a vertical microdialysis probe implanted in the paraventricular nucleus of the hypothalamus of male rats. Either apomorphine (80 μg/kgs.c.) or oxytocin (30 ng i.c.v.) increased significantly basal NO₂- and NO₃- concentration in the paraventricular dialysate, penile erection and yawning. Morphine (1, 5 and 10mg/kg i.p.) prevented dose-dependently either apomorphine or oxytocin responses when given 15min before apomorphine or oxytocin. Prevention by morphine of apomorphine and oxytocin responses was abolished by naloxone (3mg/kg i.p.) given 15min before morphine. Morphine prevented apomorphine and oxytocin responses also when given in the lateral ventricles or directly in the paraventricular nucleus. In contrast, the selective agonist of the kappa opioid receptor subtype U-69,593 was found to be ineffective. The present results confirm previous findings showing that morphine acts through μ receptors in the paraventricular nucleus to prevent apomorphine and oxytocin-induced penile erection and yawning and suggest that this morphine effect is mediated by a decreased activity of nitric oxide in the paraventricular nucleus of the hypothalamus. Received: 30 September 1996 / Accepted: 24 January 1997     

Preparation and local anaesthetic activity of benzotriazinone and benzoyltriazole derivatives

Two sets of benzotriazinone and benzoyltriazole derivatives were prepared and tested for local anaesthetic activity in comparison with lidocaine. Several of the prepared compounds exhibited a fairly good activity comparable or superior to that of lidocaine. The presence of a benzotriazinone or a benzoyltriazole moiety as an aromatic system was quite profitable for both the intensity and duration of activity. The acute toxicity in mice of the four most potent compounds of the series was also assessed. Compound 1b, which has an anaesthetic activity comparable to that of lidocaine, was also characterized by a more favourable therapeutic index. All compounds were tested in vitro to evaluate their negative chronotropic action in isolated rat right atria.     

Involvement of adenosine A1 and A2A receptors in the motor effects of caffeine after its acute and chronic administration.

The involvement of adenosine A(1) and A(2A) receptors in the motor effects of caffeine is still a matter of debate. In the present study, counteraction of the motor-depressant effects of the selective A(1) receptor agonist CPA and the A(2A) receptor agonist CGS 21680 by caffeine, the selective A(1) receptor antagonist CPT, and the A(2A) receptor antagonist MSX-3 was compared. CPT and MSX-3 produced motor activation at the same doses that selectively counteracted motor depression induced by CPA and CGS 21680, respectively. Caffeine also counteracted motor depression induced by CPA and CGS 21680 at doses that produced motor activation. However, caffeine was less effective than CPT at counteracting CPA and even less effective than MSX-3 at counteracting CGS 21680. On the other hand, when administered alone in habituated animals, caffeine produced stronger motor activation than CPT or MSX-3. An additive effect on motor activation was obtained when CPT and MSX-3 were coadministered. Altogether, these results suggest that the motor-activating effects of acutely administered caffeine in rats involve the central blockade of both A(1) and A(2A) receptors. Chronic exposure to caffeine in the drinking water (1.0 mg/ml) resulted in tolerance to the motor effects of an acute administration of caffeine, lack of tolerance to amphetamine, apparent tolerance to MSX-3 (shift to the left of its 'bell-shaped' dose-response curve), and true cross-tolerance to CPT. The present results suggest that development of tolerance to the effects of A(1) receptor blockade might be mostly responsible for the tolerance to the motor-activating effects of caffeine and that the residual motor-activating effects of caffeine in tolerant individuals might be mostly because of A(2A) receptor blockade.     

The physical state of a meal affects hormone release and postprandial thermogenesis

There is evidence that food consistency may influence postprandial physiological responses. Recently we found that homogenization of a vegetable-rich meal significantly delayed the gastric emptying rate and was more satiating than the same meal in solid-liquid form. In this present study we investigated whether homogenization also influences endocrine and metabolic responses to the meal. Eight healthy men, aged 21-28 (mean 24.5) years, were given the meal (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, with water 300 ml; total energy 2.6 MJ) in both solid-liquid (SM) and homogenized (HM) form, in random order, at 1-week intervals. Variables assayed were plasma glucose, insulin and glucose-dependent insulinotropic peptide (GIP) levels for 2 h and diet-induced thermogenesis (DIT) for 5 h. Plasma glucose pattern was similar after both meals. However, HM induced significantly greater insulin, GIP and DIT responses than SM. Mean integrated areas under the curves (AUC) were 1.7 (SEM 0.38) v. 1.2 (SEM 0.33) U/l per 120 min (P = 0.005) for insulin, 19.9 (SEM 2.44) v. 16 (SEM 1.92) nmol/l per 120 min (P = 0.042) for GIP, and 237.7 (SEM 16.32) v. 126.4 (SEM 23.48) kJ/300 min (P = 0.0029) for DIT respectively. Differences between GIP-AUC after HM and SM correlated significantly with differences between insulin-AUC after HM and SM (r2 0.62, P = 0.021). These findings demonstrate that homogenization of a meal results in a coordinated series of changes of physiological gastroentero-pancreatic functions and confirm that the physical state of the meal plays an important role in modulating endocrine and metabolic responses to food.