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C White

Publications and source records attributed to C White.

At least 19 recordsLinked to original sources
PubMed1992

Structure of calcium 2,6-difluorobenzoate dihydrate.

Ca2+.2C7H3O2F2-.2H2O, M(r) = 390.3, monoclinic, C2/c, a = 17.584 (4), b = 10.771 (3), c = 7.887 (2) A, beta = 91.28 (2) degrees, V = 1493 A3, Z = 4, Dm = 1.75, Dx = 1.74 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 4.92 cm-1, F(000) = 792, T = 293 K, final R = 0.037 for 2415 unique observed reflections. The eight-coordinate Ca2+ ion is linked to six carboxylate O atoms from four different 2,6-difluorobenzoate ions and two water molecules. Each 2,6-difluorobenzoate ion chelates one Ca2+ ion and forms unidentate bridging linkages to two other Ca2+ ions leading to a polymeric structure. Unlike the situation in calcium 2-fluorobenzoate, the two F atoms in this structure are not involved in significant C-F...H-O hydrogen bonding.

Benzoates↗
PubMed1992

Another pound of cure.

Explore the source record for details and available documents.

Health Services Accessibility↗
PubMed1992

Effects of a nursing education intervention on parents' knowledge of hydrocephalus and shunts.

The purpose of this nursing intervention study, which used a pre- and posttest design, was to determine the effect of an education program on parents' knowledge of hydrocephalus and shunt dynamics in a sample of parents of children with hydrocephalus. Study participants were parents of hydrocephalic children treated with an initial shunt or a shunt revision. The convenience sample of 41 subjects was divided into two groups (A or B). Group A participants were parents whose child received an initial shunt. Group B participants were parents whose child was admitted for a shunt revision. The shunt education intervention had three components: a shunt handbook, a preoperative teaching session with the clinical nurse specialist and a subsequent reinforcement teaching session. The pre- and posttest were the same seven multiple choice questions on hydrocephalus and shunts. In both groups, the pretest was given before the shunt education intervention. The posttest was given 2-3 weeks after the patient's surgery. There was a statistically significant change in the scores from the pre- and posttests for Group A (p = 0.0092). The nursing education appeared to have a positive effect upon this group's knowledge of hydrocephalus and shunts.

Adolescent↗
PubMed1992

Randomized trial of thrombolysis versus heparin in unstable angina.

BACKGROUND: The clinical usefulness of intravenous thrombolytic therapy in unstable angina is currently unknown, despite the pathogenetic similarity of this entity to acute myocardial infarction, for which thrombolysis has enjoyed great success. To compare the clinical benefit of intravenous urokinase with that of conventional antithrombotic therapy in preventing the progression of unstable angina to new myocardial infarction, intractable angina, or death within the first 96 hours after hospitalization, 149 patients with unstable angina were randomized to one of two intravenous thrombolytic strategies. METHODS AND RESULTS: Forty-nine patients received 3 million units urokinase i.v. over 90 minutes plus intravenous heparin (group A); 47 patients received unblinded 3 million units urokinase i.v. plus 325 mg aspirin p.o. daily (group B); and 53 patients received placebo thrombolytic infusion plus full-dose heparin (group C). The primary end point of this trial was 96-hour clinical status. There were no significant differences in the baseline characteristics (age, sex, previous myocardial infarction, hypertension prevalence, diabetes, tobacco use, or previous revascularization) among the three groups. Despite an excess of minor untoward reactions for the urokinase groups (chills, 26.5% and 23.4% for groups A and B versus 0% for group C; p < 0.01), there was no significant difference with respect to major bleeds (two, none, and two for groups A, B, and C, respectively; p = NS). At 96 hours after presentation, no significant difference emerged in the incidence of new cardiac events: new myocardial infarctions developed in 10.2% of group A, 6.4% of group B, and 3.8% of group C (p = NS); intractable angina occurred in 6.1% of group A, 10.6% of group B, and 9.4% of group C (p = NS). There were no deaths. All three groups encountered a similar incidence of overall cardiac events: 16.3%, 17.0%, and 13.2% for groups A, B, and C, respectively (p = NS). Although trial enrollment was to extend to 600 patients, interim analysis led to early cessation of enrollment due to a negative trend in respect to outcome after thrombolysis. CONCLUSIONS: High-dose intravenous urokinase followed by either heparin or aspirin can be safely administered to a broad, unselected group of patients with unstable angina. However, this study suggests that no clinical advantage is conferred by urokinase, with either adjunctive antithrombotic therapy over standard heparin therapy alone, when given relatively late (mean, 8.7 hours) after admission for unstable angina. A possible detrimental effect cannot be excluded.

Angina, Unstable↗
PubMed1992

No evidence for female-to-female HIV transmission among 960,000 female blood donors. The HIV Blood Donor Study Group.

The frequency of female-to-female HIV transmission was assessed among 960,000 female blood donors at 20 large U.S. blood centers during 1990. Of 144 HIV-seropositive women identified, 106 were interviewed. None of the interviewed women reported sex exclusively with women since 1978. Three seropositive women reported sex contact with women as well as with either bisexual men or men who had used i.v. drugs. In this large population, we identified no woman who was infected with HIV from sexual contact with another woman.

Adolescent↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1990

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↗