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Biomedical subjects

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↗
PubMed1990

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↗
PubMed1978

Fibrocystic breast disease in oral-contraceptive users. A histopathological evaluation of epithelial atypia.

Epidemiological studies show a lower frequency of fibrocystic breast disease among long-term users of oral contraceptives than among women who have never used them. Fibrocystic disease may be a precursor of breast cancer; yet the incidence of breast cancer does not appear to differ between pill-takers and nontakers. To resolve this conflict, we examined the problem from a histologic standpoint in 205 premenopausal women, and found that this decreased frequency applied only to fibrocystic disease in which epithelial atypia was minimal or absent. In women with marked atypia there was no significant difference in frequency among long-term users as compared to women who have never used oral contraceptives. These findings suggest that a spectrum of cystic disease exists and that the long-term use of oral contraceptives protects against the forms of fibrocystic disease that are not firmly associated with an increased risk of breast cancer, but not against the premalignant forms.

Adult↗
PubMed1978

Systems releasing action therapy with alcoholics: an experimental evaluation.

Described Systems Releasing Action Therapy (SRAT) and a controlled study that evaluated its effectiveness. The therapy combines physical and fantasy exercises and has its roots in the Bioenergetic and Gestalt traditions. To evaluate its effectiveness, 56 patients who were receiving treatment for alcoholism were assigned randomly to therapy and control groups. On 3-week follow-up, the therapy sample showed significantly more improvement than the controls on measures of blood pressure, physical symptoms, anxiety, hysteroid tendencies, disturbed feelings and self-image. Suggestive differences (interactions significant only at the .20 level) in favor of the therapy group also appeared on measures of vital capacity withdrawal, excessive drinking, anhedonia and four neurosis-oriented MMPI scales. However, 6-month follow-up data were relatively unimpressive. The results suggest this type of therapy is an effective one, at least for the short term.

Adult↗
PubMed1978

Interferon-associated, dsRNA-dependent enzyme activities in a mutant 3T6 cell engaged in the semiconstitutive synthesis of interferon.

Cytoplasmic extracts of untreated cultures of a virus-resistant mutant of mouse 3T6 cells, designated 3T6-VrB2, contain two double-stranded, RNA-activated enzyme activities associated with interferon action. These are the synthesis of a low molecular weight oligonucleotide inhibitor of cell-free protein synthesis from ATP, and the phosphorylation of a 67,000 dalton polypeptide by transfer of the gamma phosphate of ATP. Basal levels of both enzyme activities are detectable in extracts of untreated parental 3T6 cells, and are greatly enhanced upon interferon pretreatment. A procedure was developed, using a nonionic detergent to effect cell lysis, which allowed the analysis of the protein kinase activity from as few as 2 x 10(7) cells. Using this procedure, direct proportionalities were demonstrated between the concentration of interferon to which 3T6 cells were exposed, and both the level of protein kinase activity and the magnitude of the antiviral state were established in these cells. Furthermore, untreated cultures of 3T6-VrB2 exhibited both an antiviral state and an intracellular protein kinase activity equal to that of cultures of the parental 3T6 cells pretreated with a single concentration of mouse interferon.

Cell Line↗