Central adiposity and hemodynamic functioning at rest and during stress in adolescents

OBJECTIVE: To examine the impact of central adiposity upon hemodynamic functioning at rest and during stress in adolescents. DESIGN: Cross-sectional, correlational study. SUBJECTS: 46 White and 49 Black normotensive adolescents with family histories of essential hypertension. MEASUREMENTS: Systolic and diastolic blood pressure (SBP, DBP), cardiac output and total peripheral resistance responses were assessed at rest, during postural change, video game challenge and forehead cold stimulation. Specific lower and higher waist-to-hip ratio (WHR) tertiles were created for each gender and then integrated for analyses. This resulted in a lower WHR tertile of 11 Whites and 21 Blacks and an upper WHR tertile of 15 Whites and 17 Blacks. RESULTS: No differences in age, gender or ethnicity proportions were found between tertile groups (all P > 0.21). The upper WHR group showed greater body weight, waist and hip circumferences, body mass index (BMI), triceps skinfold and body surface area (all P < 0.001). Controlling for peripheral (that is, triceps skinfold) and overall (that is, BMI) adiposity, the upper WHR group exhibited greater SBP (that is, peak response minus mean pre-stressor level) to all three stressors and greater DBP reactivity to postural change and cold pressor (all P < 0.05). CONCLUSION: Central adiposity appears to adversely influence hemodynamic functioning during adolescence. Underlying mechanisms responsible for these associations require exploration.     

Clinical outcome of patients infected with hepatitis C virus infection on survival after primary liver transplantation under tacrolimus

In 1994, as a result of both programme evaluations which identified students' fears and apprehensions about their practical ability, and a review of the literature on skill acquisition, experiential skills teaching was resumed within the faculty. Having invested considerable finance into the reconstruction of a skills centre to teach skills, it is now imperative that its use be formally evaluated. Part of the evaluative process includes a review of the empirical literature on the acquisition of psychomotor skills in nursing. This paper summarizes this review.     

Differential acetylcholine and GABA release from cultured chick retina cells

In the present work we investigated the mechanisms controlling the release of acetylcholine (ACh) and of gamma-aminobutyric acid (GABA) from cultures of amacrine-like neurons, containing a subpopulation of cells which are simultaneously GABAergic and cholinergic. We found that 81.2 +/- 2.8% of the cells present in the culture were stained immunocytochemically with an antibody against choline acetyltransferase, and 38.5 +/- 4.8% of the cells were stained with an antibody against GABA. Most of the cells containing GABA (87.0 +/- 2.9%) were cholinergic. The release of acetylcholine and GABA was mostly Ca2+-dependent, although a significant release of [3H]GABA occurred by reversal of its transporter. Potassium evoked the Ca2+-dependent release of [3H]GABA and [3H]acetylcholine, with EC50 of 31.0 +/- 1.0 mm and 21.6 +/- 1.1 mm, respectively. The Ca2+-dependent release of [3H]acetylcholine was significantly inhibited by 1 micrometer tetrodotoxin and by low (30 nm) omega-conotoxin GVIA (omega-CgTx GVIA) concentrations, or by high (300 nm) nitrendipine (Nit) concentrations. On the contrary, the release of [14C]GABA was reduced by 30 nm nitrendipine, or by 500 nm omega-CgTx GVIA, but not by this toxin at 30 nm. The release of either transmitters was unaffected by 200 nm omega-Agatoxin IVA (omega-Aga IVA), a toxin that blocks P/Q-type voltage-sensitive Ca2+ channels (VSCC). The results show that Ca2+-influx through omega-CgTx GVIA-sensitive N-type VSCC and through Nit-sensitive L-type VSCC induce the release of ACh and GABA. However, the significant differences observed regarding the Ca2+ channels involved in the release of each neurotransmitter suggest that in amacrine-like neurons containing simultaneously GABA and acetylcholine the two neurotransmitters may be released in distinct regions of the cells, endowed with different populations of VSCC.     

Structure discovery in medical databases: a conceptual clustering approach

Clustering is an important data analysis tool for discovering structure in data sets. Although research on conceptual clustering has produced algorithms showing significant advantages over earlier numerical ones, existing methods still present some limitations regarding applicability to biomedical domains. In this paper we describe ADAGIO, a conceptual clustering algorithm combining a low-cost preordering process with a breadth-first incremental control strategy that incorporates merging and splitting operators. Experimental evaluation indicated that the algorithm achieves a good balance between structure discovery performance and computational efficiency, and demonstrated the comparative effectiveness of its missing information handling process. ADAGIO is able to handle qualitative, quantitative and mixed-type data. An application example to a cancer domain is given, where the algorithm was able to suggest interesting epidemiological interpretations.     

Moving software to a global platform

The 1990s has already seen enormous change to the computer industry in Brazil. But the greatest change of all is expected in the area of software. By the end of 2000, Brazil is out to capture 1 percent of a US $ 200 billion international software market, according to the federal Govemment's National Program of Software for Export, or Softex 2000. For Brazil, this could mean $2 billion in revenues from sales of application programs, programming tools, and multimedia entertainment and educational systems on CD-ROMs. So far, the local industry has done well. Exports in 1995 reached $100 million, about half going to the United States, again according to Softex. This occurred even though most of the Softex-supported companies still have to make their mark overseas. In 1994, Brazilian companies sold a total of $1.1 billion worth of software, which puts the industry on a par with that of India's far better known software industry, though exports account for about half of India's revenues. Brazil's software industry grew by about 25 percent over the year before. Revenues from information technology hardware, software, and services in 1994 were around 2 percent of Brazil's gross domestic product of about $552 billion     

Three unusual causes of pediatric syncope: a reaffirmation for the screening electrocardiogram

A 74-year-old patient sought treatment for visual obscuration and clinically had signs of Graves orbitopathy. Past medical history was unremarkable except for the use of antihypertensive medication. During the hospital admission, a fluorescent treponemal antibody absorption test was reactive, indicating infection with syphilis at some time in the past. Visual deterioration despite oral corticosteroid therapy prompted orbital decompression. At the time of surgery, she sustained a globe rupture. Presumably, syphilitic scleritis was responsible, in part, for scleral thinning and weakening, predisposing her to this complication. To the authors' knowledge, globe rupture has not been previously reported during orbital decompression.     

Surgical treatment of cyclosporine A- and nifedipine-induced gingival enlargement: gingivectomy versus periodontal flap

The purpose of this study was to compare probing depth resolution achieved by gingivectomy and periodontal flap techniques in the treatment of cyclosporine A- and nifedipine-induced gingival enlargement. Ten kidney transplant patients who were receiving cyclosporine A and nifedipine for at least 6 months participated in the study. Five patients were randomly assigned to the gingivectomy group and 5 patients to the periodontal flap group. Only anterior segments of the oral cavity (canine to canine) were surgically treated. Clinical measurements, including probing depths, plaque index, and gingival sulcus index, were taken at baseline, 6 weeks, 6 months, and 1 year. Results showed that probing depths, while similar for both groups in the first 6 weeks of the study, were significantly shallower for the periodontal flap group when compared to the gingivectomy group at 6 months (2.48 +/- 0.34 mm versus 4.87 +/- 0.79 mm, respectively) and 1 year (322 +/- 0.65 mm versus 6.40 +/- 1.02 mm, respectively). Within its limitations, this study suggests that the pocket reduction achieved by the periodontal flap may be sustained for longer periods of time than by the gingivectomy technique in the treatment of cyclosporine A- and nifedipine-induced gingival enlargement.     

Solid-state multiple-prism grating dye-laser oscillators

Compact solid-state multiple-prism grating dye-laser oscillators are shown to yield in excess of 9% conversion efficiency at Δv ≈ 1.12 GHz and a tuning range of 47 nm.     

Occurrence of transcranial Doppler high-intensity transient signals in patients with potential cardiac sources of embolism. A prospective study

BACKGROUND AND PURPOSE: Cerebral emboli can be recognized by typical "high-intensity transient signals" (HITS) in the transcranial Doppler (TCD) spectral curves. Patients with potential cardiac sources of embolism are at higher risk for stroke. METHODS: We examined the frequency of HITS in the left middle cerebral artery (MCA) with TCD over periods of 30 minutes in 100 patients having potential cardiac sources of embolism, as indicated by transthoracic or transesophageal echocardiography. RESULTS: Thirty-six (36%) of the patients presented with HITS. Sex, age, sufficient anticoagulation level, antiplatelet therapy, neurological symptoms, and a history of thrombosis had no influence on the prevalence and number of HITS. The patients with a single echocardiographic diagnosis were separated into eight echocardiographically defined groups: patients with (1) atrial fibrillation, (2) coronary artery disease plus ejection fraction of more than 30% including at least three wall segments of hypokinesia/akinesia, (3) coronary artery disease with less than 30% ejection fraction, (4) dilated cardiomyopathy, (5) infectious endocarditis, (6) aortic stenosis, (7) mitral stenosis, and (8) patent foramen ovale. A significant difference in HITS occurrence could not be found in any of the defined groups. Only patients with infectious endocarditis showed a tendency for a higher HITS prevalence. CONCLUSIONS: HITS are common phenomena in patients with potential cardiac sources of embolism. The clinical relevance of these HITS remains unclear.