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Biomedical subjects

F McClure

Publications and source records attributed to F McClure.

12 recordsLinked to original sources

Measuring cognitive insight in middle-aged and older patients with psychotic disorders.

The study examined the psychometric properties, factor structure and validity of a recently developed measure of insight, the Beck Cognitive Insight Scale (BCIS) and tested the relationship between the BCIS and psychiatric symptoms in a sample of middle-aged and older patients with schizophrenia or schizoaffective disorder. The BCIS measures the ability of respondents to observe and question their cognitive processes, whereas other insight scales focus primarily on knowledge about the presence of an illness and need for treatment. Participants were 164 middle-aged and older outpatients with schizophrenia or schizoaffective disorder who completed a battery of measures assessing insight, symptoms of schizophrenia and symptoms of depression. The results of a confirmatory factor analysis (CFA) supported the two-factor structure previously reported for the BCIS, with one factor labeled self-reflectiveness and the other labeled self-certainty. The BCIS showed adequate reliability and a moderate correlation with the Birchwood Insight Scale (IS). The BCIS correlated with some PANSS subscales measuring symptoms of schizophrenia, but did not correlate at a significant level with symptoms of depression. The findings suggest that middle-aged and older outpatients with schizophrenia or schizoaffective disorder respond on the BCIS in a manner similar to a younger inpatient population. This instrument is a promising tool for measuring the role of cognitive change in a broad range of patients experiencing psychosis.

Adult↗

Case-control study of non-carious cervical lesions.

An exploratory case-control study of non-carious cervical lesions was undertaken to examine the effects of a variety of risk factors. Candidate exposure variables were related to erosion, abrasion, and tooth flexure, the three principal putative causal mechanisms for cervical lesions. Because previous studies have tended to focus on specific causal mechanisms, evidence for a multifactorial etiology is inconclusive. Data describing exposure factors were obtained through clinical examination, dietary and behavioral questionnaires, and analysis of study casts from 264 subjects (137 cases, 127 control). Salivary data were also obtained for a subset of these subjects. Patient and tooth-level logistic regression models were constructed for the full subject group, and the subset with salivary data. For the two patient-level models, only exposures related to brushing entered. For tooth-level models, multiple exposures representing all three causal mechanisms were included in both models. The results suggest that non-carious cervical lesions do have a multifactorial etiology, and that multiple causal mechanisms may operate in the initiation and progression of individual lesions.

Adult↗

How dentists classified and treated non-carious cervical lesions.

All North Carolina general dentists were shown color photographs of three non-carious cervical lesions. A fourth picture showed cervical caries. Respondents were asked how they defined each lesion, its cause, treatment and frequency of appearance in practice. Cervical caries was identified and treated by almost all responding dentists, but they applied more varied terms, causes and treatments to non-carious defects.

Clinical Competence↗

Construction of an ecotropic retroviral vector expressing human insulin-like growth factor-I.

There is increasing evidence that IGF-I plays an autocrine role in a wide range of human tumours, including, in particular, adenomas of the thyroid epithelium. To investigate this further, we set out to generate a retrovirus vector which would permit experimental manipulation of the expression of IGF-I in normal and neoplastic epithelial cells. We describe here the construction and validation of a high-titre ecotropic vector which transduces stable expression and secretion of human IGF-IA, as shown by analysis of mRNA and conditioned medium from rodent epithelial target cells. This vector should be a useful tool for assessing the contribution of abnormal IGF-I expression to the neoplastic phenotype.

3T3 Cells↗

Impact of caffeine and psychological stress on blood pressure in black and white men.

The purpose of this study was to examine the effects of caffeine and psychological stress on systolic blood pressure (SBP) and heart rate (HR) in 40 healthy Black and White male regular coffee drinkers. Half the subjects had a positive family history of hypertension (FH+), and half did not. The effects of 250 mg of caffeine versus placebo (3 mg) in decaffeinated coffee were compared in a within-subject, double-blind, cross-over design. SBP and HR were measured at rest, after caffeine ingestion, during mental arithmetic stress, and during recovery. Results confirmed previous findings with White men that a moderate dose of caffeine produced significant increases in SBP and little effect on HR and that the pressor effects of caffeine and stress combined additively. Contrary to expectations, no overall race or family history differences in SBP levels or in SBP reactivity were observed. FH+ Blacks, however, evidenced slower SBP recovery than Whites. Whites evidenced higher overall HR levels than blacks, but this difference was not specific to caffeine or to mental stress. Mechanisms of racial differences in reactivity underlying differential risk for hypertension are discussed, as well as the utility of caffeine as a pharmacologic probe for such differences.

Adolescent↗

Extraction and separation of staphylococcal enterotoxin in foods: collaborative study.

A study was performed by 15 collaborators on a method for the extraction and chromatographic separation of Staphylococcus aureus enterotoxins from foods. Enterotoxin types A--E were added to crabmeat, milk, ground beef, and potato. Evaluation of the method was based on solubility of food eluates after extraction and separation of the enterotoxin; efficiency of recovery of enterotoxins A--E from foods; and serological categorizing of foods, as determined by the presence or absence of enterotoxins in the 8 food samples studied. The collaborative results on sample solubility, detection and identification of enterotoxin in foods, and differentiation of toxic from nontoxic samples showed overall positive rates of 94.79, 72.69, and 99.23%, respectively. The method, which has been substantiated by statistical evaluation, appears to be effective for the separation of staphylococcal enterotoxins from foods. The Association has adopted the method as official first action and no adverse comments have been received.

Animals↗

Collaborative study of the serological identification of staphylococcal enterotoxins by the microslide gel double diffusion test.

A collaborative study was conducted, using the microslide gel double diffusion test for enterotoxin detection by determining the staphylococcal enterotoxigenicity of 7 strains of Staphylococcus aureus. Two strains produced staphylococcal enterotoxin A (SEA), 2 strains produced staphylococcal enterotoxin B (SEB), one strain produced both SEA and SEB, and 2 strains produced neither SEA nor SEB. To ascertain the effectiveness of this method for the detection of enterotoxins, strains of enterotoxigenic staphylococci which produced small or relatively large amounts of toxin were used in the study. The cultures were grown on semi-solid brain-heart infusion agar and the culture fluids were assayed serologically for SEA and SEB. The qualitative results of this study by 16 collaborators indicated that this technique, in general, demonstrated a high degree of specificity as well as simplicity and reproducibility in the identification of the enterotoxins. Of the 16 participating laboratories, 14 reported the correct diagnoses for the 7 staphylococcal strains studied and 2 laboratories determined 6 of the 7 strains correctly. Based on these results, this method has been adopted as official first action.

Culture Media↗

Recovery and sporicidal resistance of various B. subtilis spore preparations on porcelain penicylinders compared with results from AOAC test methods.

Sporicidal test results obtained from carriers inoculated with 4 types of defined Bacillus subtilis spore preparations were compared with the standard AOAC sporicidal test using soil extract nutrient broth (SENB) B. subtilis 19659 spores. Recoveries of spores inoculated on penicylinders from B. subtilis clean spores (washed and suspended in water) and B. subtilis 19659 spores inoculated from culture filtrates according to the AOAC method were compared. Spores were exposed to 6 concentrations (0.5-3.0% w/v) of glutaraldehyde in phosphate buffer (pH 7.5) for 10 h. Concentrations were established by titrimetry and liquid chromatography. Recoveries of surviving spores were determined for 3 types of clean B. subtilis var. niger preparations, one clean B. subtilis 19659 preparation, and the SENB B. subtilis 19659 filtrates. Spore carriers, inoculated by the standard AOAC protocol, resulted in as much as a 2-log number difference in runs 1-12, but not more than 0.5 log number for each clean spore preparation. The SENB spores varied most in resistance to glutaraldehyde, with no growth in recovery media from 3 different batches of 1, 1.5, and 2% glutaraldehyde. Separate batches of SENB preparations of B. subtilis 19659 were resistant and destroyed by 1.0% glutaraldehyde, with 3.98 and 6.0 log numbers of spores on penicylinders, respectively. Clean spore preparations of B. subtilis 19659 on porcelain penicylinders were more resistant to glutaraldehyde than were SENB spores. Nutrient agar/Mg/Ca and nutrient agar/Mg spore preparations of B. subtilis var. niger showed the most uniform resistance to glutaraldehyde. Spores with calcium added showed increased resistance to glutaraldehyde. B. subtilis 19659 spores from the Columbia broth spore preparation were the most resistant and were recovered after exposure to 3.0% glutaraldehyde.

Bacillus subtilis↗

Visual screening with enzyme immunoassay for staphylococcal enterotoxins in foods: collaborative study.

Selected foods containing 4-10 ng each of a mixture of Staphylococcus aureus enterotoxin serotypes A-E were tested by 15 collaborators. An enzyme-linked immunosorbent assay (EIA) was used with polyvalent antisera to these serotypes in a polyclonal antibody double "sandwich" configuration. Controls were free of toxin. Foods (25 g test samples) were homogenized with Tris (0.25 M, pH 8.0) and centrifuged. The food extract was filtered through cotton and mixed with sample additive. For the EIA, 200 microL aliquots of the treated extracts were added to previously washed microtiter wells coated with antibody to staphylococcal enterotoxin serotypes A-E. Wells were washed and treated with the polyvalent antisera (A-E)-enzyme conjugate, and then washed again. Substrate was added, and wells were incubated. After incubation, stop solution was added. Results were determined visually and by measuring absorbance using a microtiter plate reader. In foods containing enterotoxin, bluish-green color was developed (positive result). Test solutions with absorbances > 0.200 were considered positive; those with absorbances < or = 0.200 were negative. The method is sensitive and specific, and allows the rapid assay of staphylococcal enterotoxins in foods without differentiating their serotypes. The method has been adopted first action by AOAC INTERNATIONAL.

Color↗