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Biomedical subjects

J R Davis

Publications and source records attributed to J R Davis.

At least 235 records · Page 13Linked to original sources
PubMed1985

Use of glutaraldehyde for disinfection in dialysis.

We compared Cidex HD Disinfecting Solution (CHD), a brand of glutaraldehyde disinfectant, alone and with bleach (B) to formaldehyde (F) with bleach for disinfection and cleaning of hemodialysis equipment. Two Drake-Willock central delivery systems (CDS) with 15 accompanying bedside stations and one Drake-Willock 4216 single patient delivery system (SPS) were used. The CDS designated #1, delivered dialysate to bedside stations 1 through 9, while CDS#2 supplied bedside stations 10 through 16. The study was conducted in three stages. Stage I used F six nights per week and B cleaning Wednesday (CDS#1/SPS) versus F Monday, Wednesday, and Friday with B on Wednesday (CDS#2) for four weeks. Stage II compared CHD six nights/week versus CHD Monday, Wednesday, and Friday for eight weeks. Stage III compared CDH six nights/week with B cleaning on Wednesday versus CHD on Monday, Wednesday, and Friday with B cleaning on Wednesday for four weeks. Samples of pretreated water were collected aseptically on Mondays, Wednesdays, and Fridays each week from the following sites: pre/CDS, inflow Hansen-bedside stations #5, #13, and SPS and pre-blood detector on BS #5, #13, and the SPS. During the study, 763 samples were cultured. Microbiological test results were reported as colony forming units per ml (CFU/ml). The CFU/ml were obtained by filtrating a 10 ml aliquot through a 0.45 mu filter, the filter transferred to a petri dish containing standard plate count agar and counted.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehydes↗
PubMed1984

Sex assignment in gestational trophoblastic neoplasia.

A retrospective survey was performed in 205 cases of gestational trophoblastic neoplasia with the use of routine tissue sections and quinacrine stain after hydrolysis and pronase pretreatment. The method allows scoring of nuclei simultaneously for either Y chromatin or X chromatin (Barr body) and has proved to be a valid test for sex assignment in tissue sections. Y-chromatin positivity (indicating gamete heterozygosity) was found in 16 of 182 cases (9%) of hydatidiform mole, two of four cases (50%) of invasive mole, and 14 of 19 cases (74%) of choriocarcinoma. The cytogenetic literature of 173 cases of complete hydatidiform mole indicates 8.1% have been 46,XY. Our unexpectedly high incidence of Y chromatin in malignant gestational trophoblastic neoplasia would suggest that homozygosity for a recessive mutant oncogene is not an important factor in pathogenesis of choriocarcinoma. The partial allograft theory of pathogenesis after nonmolar antecedents with attendant diminished host immunoreactivity remains a plausible consideration.

Choriocarcinoma↗
PubMed1984

Dietary obesity and exercise in young rats.

Food intake, body weight, body composition, resting metabolic rate (RMR) and the thermic effect of food (TEF) were measured in young rats, some of which were fed a high energy (HE) diet and some of which were forced to swim daily. In general, high energy feeding as compared to chow feeding, resulted in higher food intake, higher body weight, higher body fat, and a slightly lower TEF. In many cases, however, the specific effects varied with the age and sex of the animals. Animals forced to swim weighed less; were leaner; and had higher RMR and TEF than sedentary animals. The effects of exercise on energy balance were greatest in males, while the effects of the high energy diet on energy balance were greatest in females. All HE-fed rats were switched to lab chow at 104 days of age. Body weights of sedentary HE-fed rats returned to control levels but those of exercised HE-fed rats did not. Both HE-fed groups remained fatter than chow-fed controls, even two months after the diet switch.

Adipose Tissue↗
PubMed1984

Sex ratio in ectopic gestations.

Sex assignment was determined in 80 cases of ectopic pregnancy. Tissue sections of chorionic villi were stained with quinacrine for demonstration of either X or Y chromatin. Forty-one (51.2%) were X-chromatin (Barr body)-positive; 38 (47.5%) were Y-chromatin-positive, and 1 (1.3%) was Barr- and Y-positive in the same nuclei. The sex ratio of ectopic gestations in this study was 0.92 male to 1 female. Based on these data, there appears to be no predilection for ectopic implantation by either sex.

Chorionic Villi↗
PubMed1984

Clinical laboratory evaluation of a bacteriuria detection device for urine screening.

The BAC-T-SCREEN (BTS) (Marion Laboratories, Inc., Kansas City, MO) is a 2 1/2-minute urine screen designed to detect culture-negative specimens. A total of 1,609 urine specimens were tested by the BTS, and results were compared with quantitative culture methods. One hundred and forty-eight (9.2%) specimens were not screened successfully by the BTS because they contained interfering pigments or clogged the test filters. A total of 1,461 specimens were tested successfully. The sensitivity, specificity, positive predictive value, and negative predictive value for specimens containing greater than or equal to 10(5) CFU/mL were 98.0, 72.2, 57.3, and 99.0%, respectively. These values for specimens containing greater than or equal to 10(4) CFU/mL were 93.2, 77.2, 69.2, and 95.5%, respectively.

Bacteria↗
PubMed1984

Effects of Monsel's solution in uterine cervix.

Monsel's solution applied to biopsy sites causes tissue necrosis that can persist for two weeks and impede reepithelialization. Granulation tissue in the healing phase contains iron pigment residue from the agent. The pigment encrusts upon collagen and is present in siderophages for up to three months. Occasionally pigment or necrotic residues incite a foreign body giant cell reaction. Awareness is recommended in order to avoid confusion. The agent's potential effect upon the basic disease is discussed.

Cervix Uteri↗
PubMed1984

Oral contraceptive agents do not affect serum prolactin in normal women.

A total of 230 healthy women attending family planning clinics took part in a cross-sectional study, comparing contraceptive histories and serum prolactin levels. It was found that the distribution histogram of serum prolactin was markedly skewed to the right in all main groups, but that the distribution profile was not affected by use of oestrogen-containing contraceptives. Neither the dose of oestrogens nor duration of their use affected prolactin levels. We have thus found that currently available combined oral contraceptive agents have no effect on serum prolactin. Analysis of the skewed raw data yields a 'normal' range of 110-700 mU/l, higher than that usually accepted.

Adolescent↗
PubMed1984

Investigation of binding sites for follicle-stimulating hormone and chorionic gonadotropin in human ovarian cancers.

The binding of FSH and hCG to ovarian tumor biopsies from 31 women was analyzed to determine whether ovarian cancers contain receptors for gonadotropic hormones. For comparative purposes, gonadotropin binding to receptor-positive control tissues was also assessed. Specific binding was defined as [125I]hFSH and [125I]hCG binding prevented by coincubation of tissue samples with an excess of unlabeled gonadotropin. Various types of epithelium-derived tumors (serous, mucinous, endometrioid, and undifferentiated; n = 29) had low levels of specific FSH and hCG binding (less than 15% of receptor-positive control tissues) which were not dependent on tissue concentration and not saturable. A germ cell tumor had similar binding characteristics. In contrast, specific FSH binding to a granulosa cell-theca cell (GC-TC) tumor was directly proportional to tissue concentration, and binding was maximal in the presence of 100 ng/ml [125I]FSH. Scatchard analyses of FSH binding yielded a linear plot. Although the FSH-binding capacity of the GC-TC tumor (6.3 fmol/mg) exceeded that of control tissues, their binding affinities (Kd = 1.4 X 10(-9)M) were similar. Specific hCG binding to the GC-TC tumor was low and not dependent on tissue concentration. We conclude that the specific binding of FSH to the GC-TC tumor was characteristic of the interaction of gonadotropin with receptors in target tissues. However, the low level of FSH and hCG binding to tumors of epithelial origin did not represent gonadotropin-receptor binding. Thus, the common ovarian tumors of epithelial origin may not respond directly to gonadotropin, but malignancies of sex cord-stromal origin, such as GC-TC tumors, could be modulated by FSH.

Animals↗
PubMed1984

Accuracy of aspiration cytology in detecting breast cancer.

To evaluate the role of needle placement in determining accuracy and to establish criteria for clinical decision making, we used aspiration cytology to diagnose 49 palpable breast masses in patients undergoing excisional biopsy. Closed cytology, obtained by percutaneous aspiration, and open cytology, obtained by aspiration of the excised mass, were compared with histology. Nineteen (39%) of the breast masses were carcinoma. Unsatisfactory cytologic findings were frequent after both closed (37%) and open (24%) aspiration. Most of these aspirates were from mammary dysplasia, suggesting that acellularity rather than needle placement was responsible. Closed aspiration was falsely negative in one patient and falsely suggestive of cancer in five. If atypical, suspicious or malignant cytologic findings were considered to be carcinoma; closed cytology had high sensitivity (94%), low specificity (64%), and a false positive fraction of 36%. The positive predictive value was 76% and the negative predictive value 90%. Accuracy was 81%. If only suspicious or malignant results were considered positive, specificity and positive predictive value increased at the expense of sensitivity and negative predictive value but accuracy did not change. Even with optimal needle placement (open aspiration), accuracy of aspiration cytology was less than 90%.

Biopsy, Needle↗
PubMed1983

Variations of dietary-induced thermogenesis and body fatness with aerobic capacity.

Resting metabolic rate (RMR), dietary thermogenesis (DIT), aerobic capacity (VO2 max), and percent body fat were measured in a group of sixteen women and ten men. DIT was significantly positively correlated with aerobic capacity (r = 0.658). Percent body fat was significantly negatively correlated with VO2 max (r = -0.727). RMR was independent of VO2 max, or body fatness, but women had a significantly higher average RMR than men. Three men and three women participated in an endurance training program which significantly increased VO2 max. DIT was increased in proportion to the increase in aerobic capacity (rs - 0.924), RMR was unchanged, and body fat decreased in males but not females. The controversy surrounding "luxuskonsumption" may stem in part from not taking into account individual differences in aerobic capacity when measuring DIT.

Adipose Tissue↗
PubMed1983

Characterization of a new human endometrial carcinoma (RL95-2) established in tissue culture.

A new human endometrial cell line, RL95-2, derived from a Grade 2 moderately differentiated adenosquamous carcinoma of the endometrium has been passaged successfully in cell culture for more than 2 yr. The cells are characteristically epithelioid with well-defined junctional complexes, tonofilaments, filopodialike extensions, and surface microvilli. Nuclei are large, irregular, and invaginated frequently with multiple, prominent, lamellar nucleoli. The cells have a log phase doubling time of 22 to 34 h followed by continued growth at a reduced rate with no apparent plateau phase. They exhibit a strong tendency for piling up as well as for the formation of glandlike dome structures. Karyotypically the line is trisomic 8 (47,XX,+8) and has an 8% frequency of polyploidization. Both cytoplasmic and nuclear estrogen receptors are present. Antihuman alpha-keratin characterizes the cell line as epithelial, nonstromal. The RL95-2 cell line may provide a useful in vitro system for the investigation of the endocrine regulation of endometrial neoplasia.

Adenocarcinoma↗
PubMed1983

Effects of diet and exercise training on thermogenesis in adult female rats.

The effects of a cafeteria diet on body weight gain, food intake, resting metabolic rate (RMR) and the thermic effect of food (TEF) were compared in female Charles River albino rats that were either sedentary or exercise-trained. The food intakes of the exercise-trained rats on the cafeteria diet were increased to the same degree as those of the sedentary rats, however, they gained less body weight and body fat than sedentary controls. The exercise training increased RMR independent of diet, but differentially increased TEF in rats given the cafeteria diet. Conversely, sedentary rats on the cafeteria diet had significantly lower RMR, but their TEF were not different from control animals on lab chow. Thus, in addition to the direct cost of the exercise, training increased thermogenesis (RMR and TEF) which also helped prevent the dietary obesity which normally occurs with cafeteria diets.

Animals↗
PubMed1983

The effects of long-term malathion or diazinon ingestion on the activity of hepatic synthesized clotting factors.

Female Sprague-Dawley rats were placed on a drinking solution of 1 ppm Diazinon or malathion dissolved in water for 6 months. At the conclusion of the experiment liver tissue and plasma were examined. Clotting studies included the prothrombin time (PT), partial thromboplastin time (APTT), fibrinogen, and factors II, V, VII, X, plus the platelet count. Hepatic morphology, basically hepatocyte degeneration, was altered by malathion while diazinon had no notable effect. Likewise, malathion prolonged both the PT and APTT, the only changes in clotting activity.

Animals↗
PubMed1983

Cytogenetic analysis of leukaemic colonies from acute and chronic myelogenous leukaemia.

We have utilized the blast cell assay of Buick et al. (1977) to grow and subsequently cytogenetically analyze cultured colony forming cells (CFUs) from patients with acute and chronic myelogenous leukaemia (AML, CML). Cytogenetic analysis of CFUs was successful in 30/36 cases (83%), a success rate similar to direct harvesting techniques. Identical clonal chromosomal abnormalities demonstrated by direct techniques were also observed in CFUs from AML and CML. Removal of T-precursor cells by E-rosetting prior to plating did not eliminate growth of karyotypically normal cells. The combination of morphologic and cytogenetic studies performed clearly established that the assay system supports the growth of leukaemic progenitors. Although both karyotypically normal and abnormal leukaemic colonies grew in this assay, growth of leukaemic colonies was much more likely if the plated cells were karyotypically abnormal (P = 0.010). Leukaemic colony growth was also more frequent if the tritiated thymidine labelling index (LI%) of plated cells was greater than or equal to 5% (P = 0.018). Leukaemic colonies were most likely (P = 0.018) to have been derived from plated cells with both abnormal karyotype and high LI% (greater than or equal to 5%). Cytogenetic analyses from cultured cells revealed only those karyotypic features found in the uncultured cells (i.e., no additional abnormal sublines were found). However, in most cases, the greatly enhanced number and quality of mitotic figures allowed for more detailed banding analysis.

Adolescent↗
PubMed1983

Lack of effect of ethanol on plasma cortisol in man.

The effects of acute administration of ethanol were studied in a total of 18 normal male subjects. Sixteen men were given oral ethanol (2.5 ml/kg vodka or gin) and four received intravenous infusions of ethanol (1 ml/kg), at two times of day, 0900 h and 1800 h. Neither intravenous nor oral ethanol caused a specific rise in plasma cortisol, in contrast to previously reported work. There was no evidence for circadian variation in response. Since ethanol does not release plasma cortisol in normal individuals, the pathogenesis of 'alcohol-induced pseudo-Cushing's syndrome' should be re-considered.

Administration, Oral↗
PubMed1983

Rapid method for detection, identification, and susceptibility testing of enteric pathogens.

Three hundred and seven colonies believed to be enteric pathogens were selected from primary plates of MacConkey, xylose desoxycholate, or salmonella-shigella agar for inoculation to lactose-sucrose broth, urea-41 motility medium, modified Andrade glucose broth with inverted Durham tube, pregrowth broth, triple sugar iron agar, lysine iron agar (LIA), and Christensen urea agar. The rapid screen consisted of interpreting the lactose-sucrose, urea-41 motility, and modified Andrade glucose broth gas reactions after 4 to 6 h at 35 degrees C. These rapid screening biochemicals plus LIA were incubated for 24 h if further interpretation was required. Reference biochemicals (triple sugar iron, LIA, and Christensen urea agars) were interpreted at 24 h. Of 307 isolates, 49 (16%) were reported as negative for enteric pathogens after 4 to 6 h because their biochemical profiles were not compatible with those for enteric pathogens. A total of 87 (28.3%) isolates produced biochemical profiles at 4 to 6 h that were presumptive for enteric pathogens. The 87 presumptive pathogens were inoculated into the AutoMicrobic system Gram-Negative General Susceptibility Card and the AutoMicrobic system Enterobacteriaceae-Plus Biochemical Card (AMS-EBC+) after 4 to 6 h of growth in pregrowth broth. Of these isolates, 63 were confirmed to be enteric pathogens, of which 61 (96.8%) were correctly identified by the AMS-EBC+. One isolate was identified as Shigella dysenteriae by AMS-EBC+ but confirmed as Shigella flexneri biotype 6 by a reference laboratory. The other isolate was identified as Arizona hinshawii by AMS-EBC+ but was confirmed as Salmonella enteritidis. Of the 307 isolates, 166 (54.1%) required further interpretation of the rapid screening biochemicals plus LIA at 24 h; 5 of these were detected as enteric pathogens. The same 68 enteric pathogens were detected by both the rapid method and the reference method. The results from the general susceptibility card agreed with agar diffusion results at 99.2%. One Salmonella enteritidis and four Shigella spp. showed minor discrepancies with tetracycline. No very major or major discrepancies were observed.

Bacteriological Techniques↗
PubMed1983

4-h Identification of Pseudomonas aeruginosa with 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan.

A total of 361 gram-negative bacilli were evaluated for their ability to grow in the presence of 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan. The minimum time required for the production of visual turbidity in brain heart infusion broth was determined to be 4 h in shake cultures at 35 degrees C. The minimal inhibitory concentration (MIC) of 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan in brain heart infusion broth was determined for 174 isolates. The MICs for all 40 Pseudomonas aeruginosa isolates tested were greater than 50 micrograms/ml. The MICs for the other 53 pseudomonads tested were less than or equal to 5 micrograms/ml. Among 81 other gram-negative bacilli tested, the MICs for 4 were 15 micrograms/ml, the MICs for 15 were 10 micrograms/ml, the MICs for 21 were 5 micrograms/ml, and the MICs for 41 were less than or equal to 1 micrograms/ml. Based on these data, 361 gram-negative bacilli were inoculated into brain heart infusion broth containing 15 micrograms of 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan per ml and incubated on a shaker for 4 h. The only bacteria that produced visual turbidity were identified as P. aeruginosa (170 of 170 isolates).

Acridines↗