Aids education in schools.
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Acquired Immunodeficiency Syndrome↗
Biomedical subjects
C White
Publications and source records attributed to C White.
Phospholipase A2 is a major component of the salt-extractable pool of matrix proteins in adult human articular cartilage.
Adult human articular cartilage contains a component with an apparent molecular weight of 16 kd, which is extractable with high ionic strength buffers. This protein, which, in addition to lysozyme, is one of the most prominent components in salt extracts of adult cartilage, is not detectable in cartilage from newborns. We performed N-terminal sequence analysis to identify the protein. The amino acid sequence obtained for the first 20 residues was identical to that reported for phospholipase A2 (PLA2) from human placenta and human synovial cells. The extractable PLA2 was found to be active. The lack of PLA2 in salt extracts from newborn cartilage observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis was confirmed by the very low levels of PLA2 activity detectable in these preparations. PLA2 was clearly present in cartilage extracts from an 18-year-old subject and a 19-year-old subject, suggesting that its accumulation begins at some stage during the adolescent growth period. The enzyme does not appear to be released from cartilage matrix under normal physiologic conditions, and it is possible that the accumulation of PLA2 in maturing cartilage is a result of the decreased matrix turnover associated with the termination of skeletal growth. Whether PLA2 is active in the cartilage matrix, its precise localization, and its effects on the resident chondrocytes remain to be determined.
Adolescent↗
Stomatococcus mucilaginosus catheter-related infection in an adolescent with osteosarcoma.
Ours is apparently the first reported pediatric case of Stomatococcus mucilaginosus bacteremia. It is the second reported case of S mucilaginosus catheter-associated infection, but the first case successfully treated without removing the central venous catheter. This unusual organism should be added to the list of opportunistic pathogens that can be isolated from immunocompromised pediatric patients.
Adolescent↗
Podophyllotoxin--is it user friendly?
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Condylomata Acuminata↗
Is a test of cure necessary following treatment for cervical infection with Chlamydia trachomatis?
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Chlamydia Infections↗
Day-night and individual differences in response to constant-rate ranitidine infusion.
Twelve ulcer patients with inactive disease received constant-rate infusions of ranitidine, in doses of 6.25 and 10.0 mg/hr, during separate 24-h spans. Gastric pH and serum ranitidine concentrations were monitored. Serum ranitidine concentrations did not vary significantly after attainment of steady-state. For the group, gastric acidity was controlled above pH 4 during the day; however, at night, when gastric acid secretion was greatest under placebo conditions, ranitidine less effectively controlled gastric pH. There was individual variation in response to ranitidine. Patients (8/12) evidencing control of gastric acidity (pH greater than or equal to 4) for at least 16 h when infused with ranitidine (6.25 mg/h) were considered responders. Those (4/12) not so well controlled were designated poor responders. With parenteral infusion of 6.25, as well as 10.0 mg/h ranitidine, responders evidenced a relatively high 24-h mean pH and only minor day-night variation in gastric acidity. In contrast, poor responders were characterized by a low 24-h mean pH and high-amplitude circadian variation in gastric acidity. Poor responders evidenced statistically significant (p less than 0.05) lower gastric pH responses to parenteral infusions than did responders. A similar, significant difference between the two groups was observed when the percentage of time that gastric pH was maintained below 4 was considered. Differences between responders and poor responders to ranitidine infusion are unknown. Since Zollinger-Ellison syndrome patients were not included in the study, observed differences in drug response cannot be ascribed to hypersecretion of gastric acid.
Adult↗
Analysis and predictors of pulmonary vascular resistance after cardiac transplantation.
Elevated pulmonary vascular resistance is a known risk factor for early death from acute right ventricular failure after orthotopic cardiac transplantation. Patients in whom the elevated pulmonary vascular resistance is due primarily to increased left atrial pressure ("reactive") frequently have normalization of resistance after transplantation, but few studies have detailed the time course and magnitude of these changes. To analyze the response of pulmonary vascular resistance to cardiac transplantation, we analyzed data from 4353 right heart catheterizations on all 182 patients undergoing cardiac transplantation between 1981 and Jan. 1, 1990. Before transplantation 18% of patients had a pulmonary vascular resistance greater than 4 WU, 16% had a pulmonary artery systolic pressure greater than 60 mm Hg, and 16% had a transpulmonary gradient greater than 14 mm Hg. In the overall group of patients, pulmonary vascular resistance (mean value 2.63 WU), transpulmonary gradient (mean value 9.9 mm Hg), and pulmonary artery systolic pressure (mean value 48.0 mm Hg) were normalized within 1 week of cardiac transplantation. In patients with a high preoperative pulmonary vascular resistance (greater than or equal to 4 WU), the resistance fell promptly within 1 week of transplantation but continued to be slightly elevated throughout the period of follow-up. By multiple regression analysis, pulmonary vascular resistance at 1 week and 1 year after transplantation was significantly correlated with the pretransplantation resistance. Pulmonary vascular resistance anytime after transplantation was related to preoperative resistance, body surface area, and pulmonary artery diastolic pressure. Inferences: (1) As a group, cardiac transplant recipients have a normal pulmonary vascular resistance, transpulmonary gradient, and pulmonary artery systolic pressure within 1 week after transplantation with little change thereafter for at least several years. (2) Patients with reversible elevation of pulmonary vascular resistance before cardiac transplantation typically have a reactive and a fixed component. Cardiac transplantation relieves the reactive but not the fixed component. As a result, pulmonary vascular resistance early (within 1 week) and late after transplantation will have fallen but not completely normalized.
Cardiac Catheterization↗
Experience with ciprofloxacin.
The authors report results of a multicenter study of 65 patients treated with ciprofloxacin. Twenty infections were microbiologically proven; eradication of the pathogen was achieved in 80%.
Bacterial Infections↗
How easy is it to contact the duty medical doctor responsible for acute admissions?
OBJECTIVE: To ascertain ease or difficulty of contacting duty junior doctors responsible for acute medical admissions by telephone. DESIGN: Telephone survey of hospitals in six health regions in England and Wales. SETTING: 70 Randomly selected hospitals, 15 of which were excluded because of non-acceptance of acute medical admissions. PARTICIPANTS: 71 Duty doctors (duty house physicians, senior house officers, or registrars responsible for acute medical admissions) in 48 hospitals; seven duty doctors in seven hospitals were excluded (four declined to participate and three required a written explanation of the survey). 67 Doctors gave full information to all questions. MAIN OUTCOME MEASURES: Time taken for hospital switchboards and duty doctors to reply to telephone call, diagnoses of patients recently admitted, and on call rotas and hours of sleep of duty doctors. RESULTS: Hospital switchboards responded within 30 seconds in 87 (74%) calls, and in 76 calls (64%) the duty doctor requested was contacted within a further two minutes. Chest pain, possibly due to myocardial infarction, was the most common reason for acute medical admissions. Nearly half (48%) of the duty doctors in larger hospitals reported having 4-5 hours sleep or less on their nights on call. Most (30) were on a one in three rota; two were on a one in two rota. CONCLUSIONS: Despite impressions to the contrary contacting the duty medical team by telephone seemed fairly easy. Although most junior doctors were on a rota of one in three or better, insufficient recognition may be given to their deprivation of sleep during nights on duty.
Communication↗
Biosorption of radionuclides by fungal biomass.
Four kinds of bioreactor were evaluated for thorium removal by fungal biomass. Static-bed or stirred-bed bioreactors did not give satisfactory thorium removal probably because of poor mixing. An air-lift bioreactor removed approximately 90-95% of the thorium supplied over extended time periods and exhibited a well-defined breakthrough point after biosorbent saturation. The air-lift bioreactor promoted efficient circulation and effective contact between the thorium solution and the mycelial pellets. Of several fungal species tested, Rhizopus arrhizus and Aspergillus niger were the most effective biosorbents with loading capacities of 0.5 and 0.6 mmol g-1 respectively (116 and 138 mg g-1) at an inflow thorium concentration of 3 mmol dm-3. The efficiency of thorium biosorption by A. niger was markedly reduced in the presence of other inorganic solutes while thorium biosorption by R. arrhizus was relatively unaffected. Air-lift bioreactors containing R. arrhizus biomass could effectively remove thorium from acidic solution (1 mol dm-3 HNO3) over a wide range of initial thorium concentrations (0.1-3 mmol dm-3). The biotechnological application and significance of these results are discussed in the wider context of fungal biosorption of radionuclides.
Absorption↗
Nuclear binding of the estrogen receptor: a potential predictor for hormone response in metastatic breast cancer.
We have previously described an in vitro immunohistochemical test employing anti-receptor antibodies, for demonstrating the nuclear binding characteristics of estrogen receptors (ER) in breast carcinomas. Based on a retrospective analysis of twenty-five patients with estrogen receptor-positive (ER+) breast cancer who were treated with hormone therapy and whose clinical responses were evaluable, we were able to demonstrate that this test may be valuable to predict which, among the ER+ tumors (whether or not they are progesterone receptor positive, PR+), are likely to respond to hormone therapy and which may fail. While tumors in which ER exhibited abnormalities in nuclear binding behavior (ligand-independent nuclear binding or no nuclear binding) failed hormone therapy (16 out of 19 patients), those in which nuclear binding of ER appeared normal (ligand-dependent) in the in vitro test, responded to hormone therapy (5/6 patients). While our previous report dealt with the procedural details, specificity of the reagents, and the design of the study, this report addresses the clinical aspects of this study and response correlation.
Biomarkers, Tumor↗
Operation Desert Shield.
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Group Practice↗
Gastrointestinal complications after cardiac transplantation. Potential benefit of early diagnoses and prompt surgical intervention.
Acute gastrointestinal (GI) illnesses are unusual but potentially fatal complications following cardiac transplantation. A retrospective study was performed to analyze the frequency, etiology, and severity of GI complications and the potential impact of early diagnosis and prompt surgical intervention when appropriate. Between 1981 and July 1, 1988, 31 GI complications (pancreatic, 6; colonic, 6; gastroduodenal, 6; biliary, 5; esophageal, 3; appendiceal, 2; hernia, 2; and splenic, 1) occurred in 26 patients undergoing 32 cardiac transplants. Complications were most common (14 of 31 patients, 45%) within the first 30 days after transplantation. Seventeen GI complications were treated medically (2 deaths), 2 with elective surgery and 12 with emergent operations (3 deaths). The overall mortality rate was 16%. All patients who underwent emergent operations within 3 days of onset of symptoms survived; the mean interval of onset between symptoms and operation in the nonsurvivors was 10 +/- 3.8 days. We infer that among patients requiring urgent surgical intervention, successful outcome is enhanced by intense surveillance for early symptoms, prompt diagnostic evaluation, and early surgical intervention.
Acute Disease↗
Biodistribution and clearance of contrast-carrying MREV liposomes.
Contrast-carrying liposomes (CCLs) have been shown to increase the attenuation coefficient of the liver and spleen during computed tomographic (CT) imaging. A modification of the reverse-phase evaporation preparative technique ("MREV") led to production of CCLs that entrap contrast media efficiently. After intravenous injection, MREVs are phagocytized by the Kupffer cells of the liver and the macrophages of the spleen. The biodistribution and clearance of MREVs were studied to evaluate their potential for clinical use, MREVs carrying iodine-125-iotrolan were administered intravenously to 12 rats at doses of 400 mg lipid (containing 400 mg iodine) per kilogram body weight. Pairs of rats were anesthetized and scanned at 3 hours, and 1, 7, 14, 27 and 48 days; CT attenuation values of liver, spleen, blood, kidneys and bladder were measured. Immediately following CT, the rats were killed and tissue specimens were radioassayed. Maximum iodine content in liver and spleen was reached at one day and sustained at high levels for seven days. Biologic removal half-time of the agent in both the liver and spleen was six days. Maximum CT enhancements over baseline were observed at 24 hours and reached 210 delta HU in the liver and 880 delta HU in the spleen per gram iodine injected per kilogram body weight. It is concluded that MREVs have appropriate imaging characteristics, biodistribution, and clearance to be effective CT contrast agents.
Animals↗
High-frequency ventilation and extracorporeal membrane oxygenation.
Dramatic improvement in morbidity and mortality associated with neonatal respiratory failure has evolved over the last 30 years. Favorable survival statistics can be directly related to the institution and refinement of assisted ventilation techniques. Short- and long-term pulmonary complications continue to be of major concern. New ways to support the neonate in respiratory failure are being investigated. Concentrated efforts are being undertaken to find ways to safely and effectively treat these infants while decreasing the morbidity associated with therapy. Two such therapies, both experimental and controversial, which are gaining widespread recognition, are high-frequency ventilation (HFV) and extracorporeal membrane oxygenation (ECMO).
Extracorporeal Membrane Oxygenation↗
Application of DNA fingerprints for cell-line individualization.
DNA fingerprints of 46 human cell lines were derived using minisatellite probes for hypervariable genetic loci. The incidence of 121 HaeIII DNA fragments among 33 cell lines derived from unrelated individuals was used to estimate allelic and genotypic frequencies for each fragment and for composite individual DNA fingerprints. We present a quantitative estimate of the extent of genetic difference between individuals, an estimate based on the percentage of restriction fragments at which they differ. The average percent difference (APD) among pairwise combinations from the population of 33 unrelated cell lines was 76.9%, compared with the APD in band sharing among cell lines derived from the same individual (less than or equal to 1.2%). Included in this survey were nine additional cell lines previously implicated as HeLa cell derivatives, and these lines were clearly confirmed as such by DNA fingerprints (APD less than or equal to 0.6%). On the basis of fragment frequencies in the tested cell line population, a simple genetic model was developed to estimate the frequencies of each DNA fingerprint in the population. The median incidence was 2.9 X 10(-17), and the range was 2.4 X 10(-21) to 6.6 X 10(-15). This value approximates the probability that a second cell line selected at random from unrelated individuals will match a given DNA fingerprint. Related calculations address the chance that any two DNA fingerprints would be identical among a large group of cell lines. This estimate is still very slight; for example, the chance of two or more common DNA fingerprints among 1 million distinct individuals is less than .001. The procedure provides a straightforward, easily interpreted, and statistically robust method for identification and individualization of human cells.
Alleles↗
A review of brainstem strokes.
Stroke is the fifth leading cause of death and a common serious neurological problem. The location of a presumed ischemic lesion can be inferred by relating the observed signs and symptoms to the functional anatomy of the cerebral vessels. It is essential to be able to determine whether a lesion lies in the distribution of either the carotid or the vertebrobasilar arterial systems. The focus of this paper will be limited to a discussion of strokes occurring within the distribution of the vertebrobasilar system. Although nursing does not make medical diagnoses, a clear understanding of the clinical presentation and potential problems will enhance the nurse's ability to develop a comprehensive plan of care for the patient.
Brain Stem↗