The chloride-activated peroxidation of catechol as a mechanistic probe of chloroperoxidase reactions. Competitive activation as evidence for a catalytic chloride binding site on compound I.

Chloride ion (Cl-) effects on chloroperoxidase (CPO)-catalyzed peroxidation of catechol were used to probe the involvement of Cl- in CPO reactions. High concentrations of Cl- inhibit catechol peroxidation by competing with hydrogen peroxide (KI = 370 mM). However, at lower concentrations, Cl- is a linear competitive activator versus catechol (KDC = 35 mM).

Disruption of the cytokeratin filament network in the preimplantation mouse embryo.

The distribution of the cytokeratin network in the intact preimplantation mouse embryo and the role of cytokeratin filaments in trophectoderm differentiation were investigated by means of whole-mount indirect immunofluorescence microscopy and microinjection of anti-cytokeratin antibody. Assembled cytokeratin filaments were detected in some blastomeres as early as the compacted 8-cell stage. The incidence and organization of cytokeratin filaments increased during the morula stage, although individual blastomeres varied in their content of assembled filaments.

B.F. Skinner's position on aversive treatment.

In September 1987, an edited videotaped interview with B. F. Skinner was shown at the second annual Symposium on the Advancement of Nonaversive Behavioral Technology.

Preoperative whole body disinfection--a controlled clinical study.

Preoperative whole body washing with chlorhexidine scrub was compared with soap for its effect on prevention of wound infection in clean surgery. Two thousand and fifteen patients were studied using chlorhexidine scrub, placebo or plain soap. The overall infection rate in the control and placebo groups was 12.

A placebo-controlled trial of the effect of two preoperative baths or showers with chlorhexidine detergent on postoperative wound infection rates.

The effect of preoperative whole-body washing with chlorhexidine detergent on the incidence of postoperative wound infection was assessed in a placebo-controlled trial of 1989 patients. Patients bathed or showered with chlorhexidine, placebo, or conventional bar soap, on two occasions in the 24 h before operation. The overall infection rate for patients treated with chlorhexidine was 9%, against 12.

Epidemiologic aspects of a St. Louis encephalitis outbreak in Mesa County, Colorado.

An epidemic of St. Louis encephalitis in 1985 in Mesa County, Colorado, led to 17 cases, including one fatality. Risk was associated with advanced age and residence in Grand Junction, the county's principal city.

The three-decision problem in medical decision making.

Medical researchers and policy makers face decisions that require a choice from among two or more alternatives. Whereas traditional hypothesis tests cannot always serve the needs of the practitioner who needs to make a decision, a problem formulation that assigns losses to various incorrect decisions offers several advantages. With three possible decisions this approach offers a precise representation of the pragmatic and explanatory views of decision making.

Epizootic vesicular stomatitis in Colorado, 1982: infection in occupational risk groups.

In 1982-1983, an epizootic of vesicular stomatitis occurred in the western United States. Veterinarians, research workers, and regulatory personnel who were exposed to vesicular stomatitis virus were examined for patterns of human infection and prevalence of vesicular stomatitis New Jersey serotype neutralizing antibody. Insight into the mechanism of transmission was sought by comparing activities of antibody-positive and antibody-negative persons.

Rapid and specific serodiagnosis of western equine encephalitis virus infection in horses.

Paired sera from 28 nonvaccinated horses with serologically confirmed western equine encephalitis (WEE) virus infections were evaluated for immunoglobulin (Ig)M and IgG directed against WEE virus, by use of enzyme immunoassay. Twenty-one of the horses developed greater than or equal to 4-fold increases or decreases in serum IgM titers in paired serum samples, confirming the diagnosis of WEE in these horses. Of the remaining 7 horses, 1 had stable IgM titers, 1 had a 2-fold increase in IgM titer between paired sera, 2 had 2-fold decreases in IgM titer, and for 3 horses adequate volumes were not available for both sera of the pair.

Histologic observations following the placement of tricalcium phosphate implants in human intrabony defects.

Biopsies of soft tissue with visible ceramic particles were removed from the coronal part of grafted sites during reentry surgery. After 1 year there was evidence of osteoid forming alongside and within many of the ceramic particles. Viable fragments of mature bone were also observed separate from the ceramic material.

Histologic evaluation of new attachment in humans. A preliminary report.

This study was designed to evaluate the potential for regeneration of a new attachment (alveolar bone, cementum and a functional periodontal ligament) in patients whose attachment apparatus had been destroyed by periodontal disease. In each of the three parts of the investigation, the most apical level of calculus on the root served as a histologic reference point to measure regeneration. In Part I, attempts were made to initiate the formation of a new attachment by surgical debridement, crown removal (coronectomy) and submersion of the vital root below the mucosa.

The statistical content of published medical research: some implications for biomedical education.

Medical students and doctors need training in biostatistics. The use of analytic statistics in a leading general medical journal is reported. Of 760 consecutive research and review articles, 42% use statistical methods beyond elementary descriptive statistics.

A note on the Wilcoxon-Mann-Whitney test for 2 X kappa ordered tables.

Biological and medical investigations often use ordered categorical data. When two groups are to be compared and the data for the groups fall in three or more ordered categories, the Wilcoxon-Mann-Whitney (WMW) test uses information in the ordering to give a test that is usually powerful against shift alternatives. However, such applications of WMW often involve distributions for which extensive ties play an important role.

Analyzing data from ordered categories.

Clinical investigations often involve data in the form of ordered categories--e.g., "worse," "unchanged," "improved," "much improved.

Reporting clinical trials in general surgical journals.

Readers need information about the design and analysis of a clinical trial to evaluate and interpret its findings. We reviewed 84 therapeutic trials appearing in six general surgical journals from July 1981 through June 1982 and assessed the reporting of 11 important aspects of design and analysis. Overall, 59% of the 11 items were clearly reported, 5% were ambiguously discussed, and 36% were not reported.

Calcium control of glycogen synthase activities in mouse diaphragms, rat adipocytes and rat hepatocytes.

The following article provides evidence that cellular calcium controls the activity of glycogen synthase in all three major glycogen storage tissues; muscle, fat, and liver. Depletion of cellular calcium resulted in a moderate increase of glycogen synthase %I activities in intact mouse diaphragms, in isolated rat adipocytes, and in rat hepatocytes. The increase in %I activity of glycogen synthase was more pronounced when the uridine di-phosphoglucose concentration in the glycogen synthase assay was lowered from 4.

Measurement of glycosylated hemoglobins using boronate affinity chromatography.

A boronate affinity column method for the measurement of glycosylated hemoglobins was evaluated. In the procedure the glycosylated hemoglobins were bound by immobilized boronic acid to separate them from nonglycosylated hemoglobins. Elution of bound glycosylated hemoglobins was carried out with sorbitol buffer, and the absorbance was read at 414 nm.

Use of statistical analysis in the New England Journal of Medicine.

A sorting of the statistical methods used by authors of the 760 research and review articles in Volumes 298 to 301 of The New England Journal of Medicine indicates that a reader who is conversant with descriptive statistics (percentages, means, and standard deviations) has statistical access to 58 per cent of the articles. Understanding t-tests increases this access to 67 per cent. The addition of contingency tables gives statistical access to 73 per cent of the articles.

Serodiagnosis of western equine encephalitis virus infections: relationships of antibody titer and test to observed onset of clinical illness.

Sera from horses and human beings with clinically diagnosed western equine encephalitis (WEE) virus infections were tested for hemagglutination-inhibition (HI), complement-fixation (CF), and neutralizing (N) antibody to WEE virus. These tests confirmed infection in 43.8% (HI), 56.

Lactate dehydrogenase isoenzyme-1: changes during the first day after acute myocardial infarction.

We studied the time course of change of lactate dehydrogenase isoenzyme-1 (LD-1) in serum of patients suspected of having had an acute myocardial infarction. LD-1 was measured at intervals of 4-8 h during the first and second hospital days, by an immunochemical method. Of the 65 patients in this study, 26 had acute myocardial infarctions by traditional criteria.