Search PubMed⌕ Search

Biomedical subjects

J R Davis

Publications and source records attributed to J R Davis.

At least 253 records · Page 14Linked to original sources
PubMed1983

Rapid method for identification and susceptibility testing of Escherichia coli bacteriuria.

This report describes a rapid method for the identification and susceptibility testing of Escherichia coli bacteriuria by use of the Autobac urine screen (AUS), a 5-h indole test, and the AutoMicrobic system E. coli Susceptibility Card (AMS-ECSC). All specimens that were AUS negative at 3 and 5 h were reported as negative. All specimens that were AUS positive at 3 or 5 h were removed from the refrigerator and streaked to a MacConkey-blood agar biplate with a 0.001-ml calibrated loop and incubated at 35 degrees C. The standard method for identification and susceptibility testing consisted of inoculating isolated colonies into the AutoMicrobic system Enterobacteriaceae-Plus Biochemical Card and the AutoMicrobic system General Susceptibility Card. Of 915 specimens, 212 (23.2%) were AUS positive at 3 h, of which 112 (52.8%) were indole positive when tryptophan broth was tested at 5 h. The sensitivity and specificity of this screening method for E. coli bacteriuria were 78.8 and 72.2%, respectively. If contaminated cultures were excluded, specificity was 94.4%. When the indole test was positive, 10 microliters of growth from tryptophan broth was used as inoculum for the AMS-ECSC. AMS-ECSC results were final at 12 h. The sensitivity and specificity of the AMS-ECSC for identification of E. coli were 90.4 and 55.0%, respectively. If contaminated cultures were excluded, specificity was 100%. AMS-ECSC susceptibility results demonstrated an overall agreement of 94.3% with the standard method, with 0.5% very major, 3.4% major, and 1.8% minor discrepancies. The biplate was examined after overnight incubation, and when colonies compatible in morphology with E. coli were present in significant numbers, AMS-ECSC results were reported. When discrepancies were found between biplate and AMS-ECSC results, the biplate was processed in the conventional manner. A rapid method for identifying and performing susceptibility tests for approximately 70% of the specimens with E. coli bacteriuria is described.

Anti-Bacterial Agents↗
PubMed1983

Immunohistochemical demonstration of keratins in human ovarian neoplasms. A comparison of methods.

A comparison of five immunohistochemical methods for the demonstration of keratins in human ovarian neoplasms using affinity-purified polyclonal rabbit antibody was made. The use of indirect immunofluorescence on frozen sections briefly fixed in acetone was found to be the most sensitive method and demonstrated keratin in all 14 primary and 1 metastatic ovarian epithelial neoplasms studied. Protein A-peroxidase, peroxidase--antiperoxidase (PAP), indirect peroxidase, or the avidin--biotinylated peroxidase complex (ABC) methods applied to formalin-fixed tissues were less sensitive and led to false negative results in 9 of 15, 1 of 15, 8 of 15, and 6 of 15 cases, respectively. A single case of dysgerminoma failed to reveal keratin by any method.

Female↗
PubMed1982

Balanced translocation karyotypes in patients with repetitive abortion. Case study and literature review.

Cytogenetic studies were conducted upon 100 consecutive couples with abortions. Eight balanced carrier translocation karyotypes were discovered (8%): three cases of Robertsonian translocations and five reciprocal translocations. Two structural variant karyotypes and a poly-X mosaic were also found. A review of the literature on repetitive abortion revealed 82 balanced translocations in 1,331 couples, a rate of 6.2%. Cytogenetic studied should be routine for patients with repetitive abortion. In the pooled series, 3.7% of couples with translocation had wastage, including some with normal offspring; 9.2% had malformed offspring; 62% of the carrier couples lacked the malformation history. Seventy-four percent of the translocations were reciprocal; risk rates for imbalanced progeny were undefined for 90% of the carrier couples. Only 11 imbalanced conceptuses were demonstrated cytogenetically in 262 pregnancies of the carrier group.

Abortion, Habitual↗
PubMed1982

Evaluation of topically applied trans-retinoic acid in the treatment of cervical intraepithelial lesions.

The prevention and/or suppression of preneoplastic foci in animals has been convincingly demonstrated with the use of a variety of compounds, including retinoids. We report here a phase I/II trial of beta-trans-retinoic acid delivered via a collagen sponge/diaphragm insert for neoplasia of the cervix. Eighteen patients with biopsy-proved grades 2 and 3 cervical intraepithelial neoplasia underwent four consecutive daily applications of trans-retinoic aicd to the cervix. Conization of the cervix was performed 4 weeks later. Significant vaginal toxicity in 10 of 18 (55%) patients was unrelated to the concentration or carrying media of the drug. A reduction in size of the intraepithelial lesion was noted by colposcopy in six of 18 (33%) patients with complete resolution of disease at conization in two patients. A new delivery system designed to avoid vaginal toxicity while defining the optimal concentration and dosing schedule for these patients is currently under investigation.

Administration, Topical↗
PubMed1982

Concurrent sickle-cell anemia and alpha-thalassemia: effect on severity of anemia.

We studied 47 patients with sickle-cell anemia to determine the effect of alpha-thalassemia on the severity of their hemolytic anemia. We diagnosed alpha-thalassemia objectively by using alpha-globin-gene mapping to detect alpha-globin-gene deletions, studying 25 subjects with the normal four alpha-globin-genes, 18 with three, and four with two. The mean hemoglobin, hematocrit, and absolute reticulocyte levels (+/- S.D.) were 7.9 +/- 0.9 g per deciliter (4.9 +/- 0.6 mmol per liter), 22.9 +/- 2.9 per cent, and 501,000 +/- 126,000 per cubic millimeter, respectively, in the non-thalassemic group; 9.8 +/- 1.6 g per deciliter (6.1 +/- 1.0 mmol per liter), 29.0 +/- 5.0 per cent, and 361,000 +/- 51,000 per cubic millimeter in the group with three alpha-globin genes; and 9.2 +/- 1.0 g per deciliter (5.7 +/- 0.6 mmol per liter), 27.5 +/- 3.0 per cent, and 100,000 +/- 15,000 per cubic millimeter in the group with two alpha-globin genes. Deletion of alpha-globin genes was also accompanied by a decreased mean corpuscular hemoglobin concentration (MCHC) in post-reticulocyte erythrocytes and by increased hemoglobin F levels. The decreased intraerythrocytic hemoglobin S concentration and elevated hemoglobin F levels associated with alpha-thalassemia appear to diminish the degree of hemolytic anemia found in sickle-cell disease.

Adolescent↗
PubMed1982

Effects of early cold adaptation on food efficiency and dietary-induced thermogenesis in the adult rat.

The food intakes of male and female rats (Harvard strain) adapted to cold (5 degrees C) starting at weaning were studied in the cold and during reacclimation to 25 degrees C. Following 24 hr food deprivation, the male rats regained the weight they had lost without making up for the food they had missed (increased food efficiency), while the female rats ate 75% more food than they had missed in regaining their body weights (decreased food efficiency), independent of the temperature at which the animals were housed. On a high fat diet, both cold groups gained less weight than did the two control groups. However, each female group gained significantly less weight than its same temperature male group. Dietary-induced thermogenesis was significantly enhanced in male cold adapted rats 3 months after reacclimation to the zone of thermal neutrality but not in cold adapted female rats. Sex and strain differences are discussed. These data indicate that early chronic cold exposure results in both immediate and long-term changes in food efficiency and metabolism in adult rats, but the effects vary with the sex of the animal.

Acclimatization↗
PubMed1982

Reduced training duration effects on aerobic power, endurance, and cardiac growth.

Thirteen subjects participated in an exercise program of bicycling and running 40 min/day, 6 days/wk. After 10 wk they continued to train either 26 of 13 min/day for an additional 15 wk. Intensity and frequency for the additional 15 wk remained the same as the last 3 wk of training. This study was undertaken to gain further insights into whether the increases in maximum uptake (VO2 max), endurance, and cardiac size can be maintained with reduced training durations. The average increases in VO2 max in response to 10 wk training were between 10 and 20% during the bicycle and treadmill testing. After reduced training, VO2 max continued to remain at the training levels in both groups. Short-term endurance (approx 5 min) was also maintained by both groups. Long-term endurance (2 h or more) remained the same in the 26-min group but decreased significantly (10%, 139-123 min) in the 13-min group. Calculated left ventricular mass increased 15-20% after training and remained elevated after reduced training in both groups. We conclude that it is possible to maintain almost all of the performance increases with up to a two-thirds reduction of training duration. Nevertheless, the data provide initial evidence that all aspects of the endurance-trained state may not be regulated uniformly in reduced training, particularly since VO2 max and short-term endurance were maintained, but long-term endurance decreased in the 13-min group.

Adult↗
PubMed1982

Utility of thyroid aspiration biopsy.

The utility of fine-needle aspiration biopsy to detect carcinoma in thyroid nodules was evaluated by a decision-analysis approach in 102 patients. The procedure caused no morbidity. Cytologic diagnoses were categorized as unsatisfactory (4), no abnormality detected (61), atypical (13), suspicious for malignancy (14), malignancy (2), and inflammation (8). The duration of follow-up averaged 13 months. Of 21 thyroidectomy patients, 10 (48%) had carcinoma. Half of the ten patients operated upon for suspicious cytologic findings were found to have malignancy. Assuming criterion I, that atypical, suspicious, or malignancy results indicated cancer, sensitivity was 90%, specificity 77%, false positive fraction 23%, positive predictive value 31%, negative predictive value 99%, and accuracy 79%. Assuming criterion II, that only suspicious or malignancy cytologic findings represented carcinoma, sensitivity was 70%, specificity 90%, false positive fraction 10%, positive predictive value 44%, negative predictive value 96%, and accuracy 88%. We conclude that sensitivity and specificity of fine-needle aspiration biopsy vary depending upon the use of criterion I or II. Accuracy is highest if atypical results are not considered to represent carcinoma. Positive predictive values remain low and negative predictive values are high in either case. The utility of fine-needle aspiration biopsy when interpreted in relation to clinical criteria is supported by these results.

Adolescent↗
PubMed1981

Improved fluorescence method for identifying sex chromatin in formalin-fixed tissue.

An improved fluorescence method for demonstrating sex chromatin in formalin-fixed tissue is described. Deparaffinized sections are pretreated with pronase, then acid hydrolysis, before staining with quinacrine dihydrochloride and mounting in buffered Gelvatol. Optimized fluorescence of nuclei allows recognition of either Y chromatin or Barr body in interphase nuclei. The method is a useful tool in sexing early conceptuses and teratomata using an extensive paraffin-block storage resource.

Formaldehyde↗
PubMed1981

Clinical laboratory evaluation of the automicrobic system Enterobacteriaceae biochemical card.

The AutoMicrobic System Enterobacteriaceae Biochemical Card (AMS-EBC; Vitek Systems, Inc.) was evaluated in two clinical microbiology laboratories. A total of 502 consecutive clinical isolates representing members of the family Enterobacteriaceae were tested in parallel with the AMS-EBC, API 20E, and Enterotube II systems. Discrepancies between systems were resolved with the conventional methods of Edwards and Ewing (P. R. Edwards and W. H. Ewing [ed.], Identification of Enterobacteriaceae, 1972) and Ewing and Martin (W. H. Ewing and W. J. Martin, in Manual of Clinical Microbiology, 1974) AMS-EBC correctly identified 96.6% and incorrectly identified 3.4% of the isolates. When 12 or more isolates of a species were evaluated, Serratia marcescens, Proteus mirabilis, and Enterobacter cloacae posed the greatest challenge to the systems, with 92.6, 95.2, and 95.3%, respectively, being correctly identified. To confirm the accuracy of identification when all systems agreed, 93 randomly selected isolates were identified by conventional methods. The percent agreement was 100%. The reproducibility of triplicate determinations on 93 randomly selected isolates with the AMS-EBC was 99.6%. The AMS-EBC was found to be an easy, rapid, and accurate method for identification of Enterobacteriaceae.

Bacteriological Techniques↗
PubMed1981

Partial prevention of glucocorticoid-induced muscle atrophy by endurance training.

Male rats were either sham-operated (N) or castrated (C) at 65 days of age. They were further subdivided into sedentary or exercise groups that were trained by treadmill running 5 days/wk for 12 wk. During the last 10 days of training, the animals received daily subcutaneous injections of cortisone acetate (CA) (100 mg/kg) or 1% carboxymethylcellulose. Body weight decreased approximately 25% in all groups that received CA. The fast-twitch plantaris and gastrocnemius muscle weights were approximately 35% lower in CA-treated versus cortisone-free N and C sedentary animals. Exercise prevented from one-fourth to one-half of the muscle weight loss in N and C runners when compared to their respective pair weight controls. Muscle weights of the CA-treated freely eating N controls were significantly less than that of N runners that received CA. In plantaris muscles of both N and C animals that received CA, total protein concentration and citrate synthase activity, a mitochondrial marker, remained constant, but their amounts per muscle decreased in proportion to the atrophy. However, myoglobin concentration increased in plantaris muscles of CA-treated animals, although total myoglobin per muscle was reduced slightly. Myoglobin levels were increased in plantaris muscles both as a result of training and CA, but citrate synthase activity was increased only as a result of the exercise. These results show that exercise can retard the glucocorticoid-induced muscle atrophy.

Animals↗
PubMed1981

Expression of silver-stained nucleolar organizing regions (Ag-NORs) in human cancer.

Five cases of ovarian adenocarcinoma, three cases of endometrial adenocarcinoma, and one case of transitional cell carcinoma of the bladder have been studied for expression of silver-stained nucleolar organizing regions (Ag-NORs). The modal chromosome number of these tumors varied from 37 to 72, with a wide range of chromosome numbers (13 to 150). The modal number of Ag-NORs in this sample varied from 3 to 7. Regression analysis among and between tumors demonstrated a proportionate increase in the number of Ag-NORs with increasing number of total chromosomes and increasing number of acrocentric chromosomes (r = 0.64 and 0.75, respectively). Modal assessment of Ag-NORs in both peripheral blood lymphocytes (PBLs) and cultured tumor cells in one patient revealed identical modes in normal and malignant cells. Also, no difference in the expression of Ag-NORs was observed between tumor cells obtained at biopsy and placed for 48 h in agar culture and tumor cells established in finite monolayer culture. Our study provides further evidence for a proportionate increase in Ag-NORs with increasing numbers of acrocentric chromosomes and total chromosomes.

Adenocarcinoma↗
PubMed1981

Particle clearance from the respiratory tract as a test of toxicity: effect of ozone on short and long term clearance.

The ability of the lung to mechanically remove inhaled deposited particles is an important mammalian defense mechanism that can be evaluated in the laboratory. Experiments that measure clearance kinetics have been performed by various investigators using human as well as large and small laboratory animals as subjects. Several agents have been shown to significantly alter clearance phenomena in the lung. This paper describes quantitative clearance experiments that used radioactive tracer particles to assess lung damages after exposure of rats to ozone, a photochemical air-pollutant gas. Radioactively labeled tracer microspheres were inhaled by groups of 30 rats prior to exposure to ozone. Ozone levels studied were 0.4, 0.8, and 1.0 ppm and all exposures were 4 hr in length. These exposures caused a delay in the early (0-50 hr postdeposition) clearance and an acceleration in the late (50-300 hr postdeposition) clearance rate of the tracer particles. Dose response curves show that clearance was affected more by the higher concentrations of ozone.

Aerosols↗
PubMed1981

H-Y antigen in XO/X,iso(X) mosaic Turner syndrome.

Androgen excess, found occasionally in gonadal dysgenesis, may be associated with hilus cell hyperplasia within the gonadal streaks. This report describes a phenotypic female with Turner syndrome, clitoromegaly, hilus cell hyperplasia, and a gonadal-to-peripheral venous step-down gradient for testosterone, androstenedione, and estradiol. Cytogenetic analysis of cells from peripheral blood and both streak gonads revealed a mosaic karyotype, 45,X/46,X,iso(X). The isochromosome was a nonfused dicentric type (pter leads to q2105 leads to pter). Despite absence of the Y chromosome, serologic analysis revealed the presence of H-Y antigen, thereby suggesting occult Y chromosomal function in the patient's gonads.

Adolescent↗