Characteristics of HIV-positive patients treated in a psychiatric emergency department.

OBJECTIVE: Knowledge about the characteristics of patients using psychiatric emergency services is expanding. However, the prevalence of HIV infection among patients treated at psychiatric emergency departments is not known, and neither are the characteristics of HIV-positive patients seen in this setting. METHODS: To estimate the prevalence and demographic and clinical correlates of HIV infection among patients utilizing psychiatric emergency services in a level 1 trauma center, the authors analyzed data from a series of 58,301 consecutive visits (28,817 unique patients). RESULTS: Of the total psychiatric emergency visits, 2.0% were by HIV-positive patients, who were more likely to be male, homeless, or African American. These patients were also more likely to show dementia or to be suicidal, abusing substances, or coping with borderline personality disorder. CONCLUSIONS: More precise description of HIV-positive patients visiting psychiatric emergency departments may help elucidate the needs of this population and help plan for improvements in care in this setting.

Gamma-hydroxybutyric acid (GHB) withdrawal: a case report.

GHB is an increasingly popular drug of abuse that can be associated in select cases with growing dependence and a severe withdrawal syndrome. While benzodiazepines are recommended for treatment of the withdrawal syndrome, some cases have been described as benzodiazepine-resistant. The authors describe treatment of such a case, which was unsuccessfully treated initially with benzodiazepines, then successfully treated with adjuvant atypical neuroleptics, and offer a possible neurochemical explanation for why such agents may be theoretically more effective than benzodiazepines in treating GHB withdrawal.

Perivascular cells in a skin graft are rapidly repopulated by host cells.

Survival of grafted tissues is dependent upon revascularisation. This study investigated revascularisation in a murine skin graft model, using two methods. The first involved 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI) labelling of the wound bed, prior to replacing the skin graft, to allow tracking of host cells into the grafts. At time points between day 3 and day 14 post-surgery, DiI-labelled cells which had tracked into the grafts, were found to co-localise with CD31 positive endothelial cells and patent perfused vessels (fluorescein isothiocyanate (FITC)-dextran perfusion), to show possible association with the vasculature. To further differentiate between graft and host-derived cells, C57BL/6 wild-type grafts were placed on enhanced-green fluorescent protein (e-GFP) transgenic mouse hosts, and at set times post-grafting examined using confocal microscopy. Patent vessels were found at all depths of the graft by day 3. Host (DiI- or GFP-positive) cells were predominantly co-localised with graft vessels in grafts from day 3 onwards, with a similar morphology to control skin. Significantly more GFP labelled host cells were visualised in the superficial dermis at day 5 compared to day 3. Initial restoration of circulation appears to be due to linkage between existing graft and bed vessels, followed by an influx of host cells with a definite perivascular distribution. These findings have implications for skin autografts and tissue engineered skin substitutes.

Disclosure of HIV status and sexual orientation independently predicts increased absolute CD4 cell counts over time for psychiatric patients.

OBJECTIVE: The objective of this study was to replicate the relationship between disclosure of sexual orientation and immune functioning in HIV-positive persons and to extend those findings to a different type of disclosure (HIV status) and a different population (psychiatric outpatients in a publicly funded HIV/AIDS clinic). METHODS: A sample of psychiatric outpatients (N = 373) from a large, urban HIV clinic was assessed for level of sexual orientation and HIV status disclosure as well as absolute CD4 cell counts over time. Mixed-effects random regression analysis was used to build a predictor model that included biobehavioral covariates. RESULTS: Consistent disclosure of both sexual orientation and HIV status independently predicted increased CD4 cell counts over time controlling for important biobehavioral covariates. The only other significant effects in the model were baseline CD4 cell count and number of days between assessment of disclosure and assessment of CD4 cell count. CONCLUSIONS: Relieving potential psychological distress by disclosing sexual orientation and HIV status has a positive impact on CD4 cell counts over time even among outpatients stressed by psychiatric illness and economic disadvantage. Additional research is needed to understand whether and under what conditions disclosure should be part of HIV disease management.

Radio frequency hearing: electrostrictive detection and bone conduction.

A hearing aid patented by C. R. Schafer and supposedly based on detection of an amplitude-modulated carrier wave in the auditory cortex was re-examined. It is shown here that the hearing aid actually works by bone conduction of sound. It is concluded that detection of the modulation signal occurs by electrical nonlinearities and electrostriction in the bones of the face and skull.

Reproductive and teratologic effects of electromagnetic fields.

The reproductive risks of electromagnetic fields (EMF) were evaluated based on an extensive review of the scientific literature pertaining to human epidemiologic studies, secular trend data, in vivo animal studies and in vitro studies, and biologic plausibility. The epidemiologic studies involving the reproductive effects of EMF exposures to human populations have included populations exposed to: (1) video display terminals (VDTs), and (2) power lines and household appliances. The clinical use of diagnostic MRI (magnetic resonance imaging) has been increasing, but there are few reports or studies of pregnant women or individuals of reproductive age who have been exposed to MRI, and whose reproductive performance has been evaluated. The population that has been studied most frequently are women exposed to VDTs, but their EMF exposures are extremely low and frequently are at the level of the ambient EMF in a house or office. The results of epidemiologic studies involving VDTs are generally negative for the reproductive effects that have been studied. Based on the number of studies, the exposure levels, and the fairly consistent results, it can be argued that VDT epidemiologic studies should no longer be given priority. There have been fewer studies concerned with the reproductive risks of power lines, electric substations, and home appliances. In some publications, positive findings for reproductive risks were reported, but the more consistent findings indicate that EMF, even at these higher exposures, do not generate a measurable increase in reproductive failures in the human population. When compared to other fields of human epidemiology, it is obvious that these studies have many difficulties. Exposures are rarely determined. Studies frequently involve small sample sizes and the investigators rarely have a combined expertise in EMF physics, engineering, and reproductive biology. Because of the allegation that there may be particular windows of frequency, wave shape, and intensity that may be deleterious, it is impossible to disregard low frequency EMF exposures as having no deleterious reproductive effects. Yet the epidemiologic data that are available would point in that direction. Secular trend data analysis of birth defect incidence data indicate that increasing generation of electric power during this century is not associated with a concomitant rise in the incidence of birth defects. There are over 70 EMF research projects dealing with animal and in vitro studies that are concerned with some aspect of reproduction and growth. Unfortunately, a large proportion of the embryology studies utilized the chick embryo and evaluated the presence or absence of teratogenesis after 48 to 52 hours of development.(ABSTRACT TRUNCATED AT 400 WORDS)

Activation of the complement system by recombinant tissue plasminogen activator.

Recent trials have shown that recombinant tissue plasminogen activator (rt-PA) is an effective thrombolytic agent in patients with acute myocardial infarction. Because rt-PA converts plasminogen to plasmin, which is known to activate complement in vitro, we tested the hypothesis that rt-PA can induce in vivo activation of complement. Studies were performed in 12 patients with acute myocardial infarction. Six control patients had patent coronary arteries and did not receive rt-PA; these patients had normal values of the components of the complement system C4a (409 +/- 111 ng/ml) and C5a (8.8 +/- 1.8 ng/ml) with a slight elevation of C3a (204 +/- 6.6 ng/ml) in samples collected before coronary arteriography (253 +/- 25 minutes after onset of pain). After coronary arteriography, there was a slight decrease in the values of C4a (224 +/- 37 ng/ml), C5a (7.3 +/- 1.3 ng/ml) and C3a (164 +/- 35 ng/ml). The remaining six patients had complete coronary occlusion and received rt-PA (80 to 150 mg intravenously). In this treated group, before coronary arteriography the values of C4a (406 +/- 51.6 ng/ml) and C5a (8.1 +/- 1.9 ng/ml) were normal, and those of C3a were slightly elevated (250 +/- 76 ng/ml). All complement values obtained before rt-PA were similar to those in the untreated group. However, after administration of rt-PA (but before any angiographically detectable reperfusion), there was a striking increase in C4a (2,265 +/- 480 ng/ml; p less than 0.01), C3a (600 +/- 89 ng/ml; p less than 0.05) and C5a (30.0 +/- 4.5 ng/ml; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Rhabdomyolysis in thyroid storm.

This is the first reported case of thyroid storm complicated by rhabdomyolysis with acute reversible renal failure. The only possible causes for the rhabdomyolysis were inherent features of thyroid storm. Although hyperthyroid patients characteristically have normal or low serum levels of muscle enzymes, this case report demonstrates that rhabdomyolysis with elevated serum levels of muscle enzymes can occur with hyperthyroidism. An appreciation of the potential for rhabdomyolysis in hyperthyroidism should facilitate prompt initiation of aggressive therapy for myoglobinuria and thereby limit the severity of acute renal failure in these already very sick patients.

Design considerations in power spectra measurements by diffraction of coherent light.

The estimation of the spectral density of a spatial random process by diffraction requires that the parameters of the diffraction system be compatible with the statistical properties of the process. Otherwise, the estimate of the spectrum can be unstable or unduly biased. The relation between the second-order statistics of the process and the parameters of a basic diffraction system that are required for reasonable spectral estimates is investigated. Such parameters include aperture dimensions, wavelength, focal length of the lens, and scanning slit size. With the typical diffraction system, it is difficult to estimate the power spectrum because of the presence of the zero-order aperture-diffracted light. A technique is furnished in this paper for spectral estimation at dc. Experimental results are furnished for film grain and total film noise. It is shown that the residual phase noise of film at dc even under so-called matched conditions is large enough to prevent the accurate estimation of the dc value of grain noise.

Real-time electrooptical signal processors with coherent detection.

In conventional real-time electrooptical signal processors, the variation of the output intensity with time is directly detected with a photodetector. As a result of this, any information carried in the phase of the light is lost. However, if the light is detected coherently, i.e., it is heterodyned with another coherent local oscillator light source on the detector surface, the phase associated with the amplitude of the light may be preserved. This paper presents the results of a theoretical and experimental study of the properties of real-time electrooptical spectrum analyzers with coherent detection. Basic equations of operation are presented and discussed, and confirmed by experiment, and it is concluded that the construction of such devices is feasible.