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Biomedical subjects

K Watkins

Publications and source records attributed to K Watkins.

35 records · Page 2Linked to original sources
PubMed1994

Comparative study of infectious complications of different types of chronic central venous access devices.

BACKGROUND: Various devices for central venous access are widely used in patients with cancer. The authors studied the incidence of infectious complications affecting these different devices. METHODS: A retrospective study of 111 central venous access devices (VAD) placed in 1992 was conducted. RESULTS: Subcutaneous ports were placed in 42 patients, single lumen Groshong catheters in 45, single lumen Hickman catheters in 15, double lumen Hickman catheters in 5, and double lumen Groshong catheters in 4. Prognostic factors analysis was performed with the log rank test and Cox's multivariate analysis. Different VAD types were compared with the likelihood ratio test. There was no significant difference in the risk of VAD-related infection between Hickman and Groshong catheters. Double lumen catheters were slightly more likely to cause infectious complications than single lumen catheters, although the difference was not statistically significant (P = 0.072 and 0.083 for bacteremia and site infection, respectively). No significant difference was observed in the risk of infection between subcutaneous ports and external catheters. Multivariate analysis using Cox's proportional hazards model demonstrated age younger than 50 years as the only significant risk factor, thus younger patients should be monitored more closely. CONCLUSIONS: No significant difference was observed in the risk of infection between subcutaneous ports and external catheters. There was a slightly higher risk of infection in double lumen catheters than single lumen catheters, although the difference did not reach statistical significance. Considering the small sample size, the results should be confirmed in larger prospective studies.

Adult↗
PubMed1994

Collagen mRNA content and distribution in the lungs of rats exposed to ozone.

cDNAs, synthesized by the polymerase chain reaction (PCR) technique, were used to quantify mRNA concentrations for the alpha 1 (I) and alpha 1 (III) chains of collagen types I and III and for beta-actin in the lungs of rats exposed to either filtered air or to 1.2 ppm of ozone. The alpha 1 (I) procollagen mRNA concentration was increased by about 30% in the lungs of rats exposed to ozone, while the concentrations of the mRNAs for alpha 1 (III) procollagen and for beta-actin were the same in the lungs of control and ozone-exposed animals. The lungs from the rats exposed to 1.2 ppm of ozone preferentially synthesized type I collagen as compared with controls. Sites of increased expression of the alpha 1 (I) procollagen mRNA were detected by in situ hybridization in lung sections embedded in paraffin prepared from rats exposed either to filtered air or to ozone. The lungs from rats treated with ozone focally expressed increased amounts of alpha 1 (I) procollagen mRNA in the lung parenchyma at the septal tips and the bronchiole-alveolar duct junctions. They also showed an apparent diffuse increase in alpha 1 (III) procollagen mRNA expression. We conclude that exposure of rats to high concentrations of ozone causes a specific increase in the lung content of mRNA for the major chain of type I collagen.

Actins↗
PubMed1993

Peripheral blood stem cells harvested during marrow recovery from disease-specific chemotherapy shorten duration of neutropenia in patients undergoing autologous bone marrow transplantation.

A total of 41 patients who underwent autologous bone marrow transplantation without the use of granulocyte-macrophage colony-stimulating factor were retrospectively evaluated to determine whether the infusion of peripheral blood stem cells collected during the period of recovery of bone marrow from previous disease-specific chemotherapy could shorten the time to bone marrow engraftment after transplantation. Of the 41 patients, 24 patients received bone marrow only (group 1), 8 patients received bone marrow plus steady-state peripheral blood stem cells (group 2) and 9 patients received bone marrow plus rebound peripheral blood stem cells collected during the period of recovery from disease-specific chemotherapy (group 3). Infusion of rebound peripheral blood stem cells (group 3) accelerated recovery of white blood cells and neutrophils and resulted in a white blood cell count of > 10(9)/L by day 15 compared with day 25 in group 1 (P < 0.001), and a neutrophil count of > 0.5 x 10(9)/L by day 16 versus day 26 in group 1 (P = 0.0034). Addition of steady-state peripheral blood stem cells (group 2) did not hasten myeloid engraftment, and recovery of platelets was not improved in either group given peripheral blood stem cells. Compared with patients in group 1, patients in group 3 required 7 fewer days of parenteral antibiotics (25 days versus 18 days, respectively; P = 0.0072) and were discharged about 3 weeks earlier than patients in group 1 (day + 41 verus day +21; P = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Mortality among workers exposed to polychlorinated biphenyls.

On the basis of evidence from animal studies, polychlorinated biphenyls (PCBs) are considered potentially carcinogenic to humans. However, the results of studies in human populations exposed to PCBs have been inconsistent. The authors conducted a retrospective cohort analysis (1957-1986) comparing the mortality of 3,588 electrical capacitor manufacturing workers with known exposure to PCBs with age-, sex-, and calendar time-specific mortality rates for all whites in the United States. Proportional hazards modeling was also performed to examine the association between cumulative PCB exposure and site-specific cancer mortality. All-cause mortality (192 deaths observed, 283.3 expected) and total cancer mortality (54 deaths observed, 63.7 expected) were lower than expected. More deaths were observed than expected for malignant melanoma (8 observed, less than 2.0 expected) and cancer of the brain and nervous system (5 observed, 2.8 expected). The average estimated cumulative dose for the cases of brain cancer (22.9 units) was greater than for other workers (12.9 units), but the 95% confidence intervals around this difference were broad. The risk of malignant melanoma was not related to cumulative PCB exposure. These results provide some evidence of an association between employment at this plant and malignant melanoma and cancer of the brain. The possibility that the results are due to chance, bias, or confounding cannot be excluded.

Brain Neoplasms↗
PubMed1991

The World Health Organisation goals for oral health: a progress report.

Global oral health goals for the year 2000 were adopted in 1981 by the World Health Organisation. A literature review and collation of available data relating to progress towards these goals have been carried out. Their appropriateness and value as measures of oral health and disease trends are discussed. The general conclusions of the study were that the concept of global goals was valuable but that the lack of standardised data collection and publication made it difficult to evaluate progress towards attainment of the goals.

Adolescent↗
PubMed1990

General practice theophylline audit in the Exeter Health District.

The serum theophylline concentration was determined in 150 asthmatic patients who received treatment from General Practitioners in the Exeter Health District. The serum theophylline concentration was below the therapeutic range in 75% of the patients evaluated. There was no correlation between serum concentration and daily dose, even when the latter was calculated with respect to bodyweight or body surface area. It was concluded that a theophylline Therapeutic Drug Monitoring (TDM) service should be available for general practice patients.

Asthma↗
PubMed1990

Hemolytic anemia in a cancer patient treated with recombinant interferon-gamma.

Currently, three classes of interferon are used in the treatment of malignancies. Interferon-gamma is the best studied. Bone marrow suppression as well as immune hemolytic anemia have been described. Heretofore, only bone marrow suppression has been attributed to interferon-gamma (IFN gamma). In this report, we describe a woman with lung cancer being treated with IFN gamma in whom acute hemolytic anemia occurred. Immune hemolysis did not appear to be the cause. We concluded that in addition to bone marrow suppression, hemolysis should be considered in a patient receiving IFN gamma in whom an unexplained drop in hematocrit occurs.

Adenocarcinoma↗
PubMed1990

Phase I study of combination recombinant interleukin-2 and interferon gamma in patients with advanced malignancies.

A phase I trial of interleukin-2 and interferon gamma combination treatment in patients with advanced malignancies was performed based on preclinical in vitro and in vivo data which demonstrated synergistic antitumor effect. The toxicities, immune parameters, and tumor responses are described. The clinical and biologic maximal tolerated doses were extrapolated from these data.

Adolescent↗
PubMed1989

Single-stranded DNA gaps, tails and loops are repaired in Escherichia coli.

Uniformly methylated heteroduplex plasmids which contained 6 mismatched regions, including loops of 24, 30, 248 and 283 nucleotides, as well as single-stranded gaps and free ends were introduced into a recombination-deficient strain of bacteria, and the products of repair were analyzed. The results indicate that these cells are capable of repairing all of these structures, although with different efficiencies. Repair of single-stranded gaps and free ends, which occurs most efficiently, is always associated with acquisition of information from the uncut strand (unidirectional repair). Regions containing single loops or twin loops were repaired at similar efficiencies. In these cases each of the two strands was capable of acting as the template for repair (bidirectional repair). At sites containing twin or substitution loops, the larger of the loops was removed twice as efficiently as the smaller loop. DNA sequencing of the repaired regions indicated that the repair is precise. The data also suggest that markers separated by only 58 nucleotides do not always segregate together indicating that repair tracts may be relatively short.

Base Composition↗
PubMed1985

Determination of organic acids in seven wheat varieties by capillary gas chromatography.

Fresh wheat tops were extracted with acidic 90% ethanol, and the ethanol was evaporated and a portion of the aqueous residue loaded onto DEAE-Sephadex. Organic acids were eluted with pyridinium formate and then lyophilized and the dried residue was derivatized with 1% trimethylchlorosilane in bis(trimethylsilyl)trifluoroacetamide. The acids were then quantitatively determined using capillary gas chromatography and identified using capillary gas chromatography-mass spectrometry. The acidic ethanol extraction of fresh plant tissue was quantitative for all acids except citric while losses in the remaining procedures were controlled by using an internal standard. The ion exchange chromatography made the greatest contribution to experimental error, imposing a minimum loading requirement of 0.1 mumol of each acid for adequate precision. Organic acid profiles were determined for seven wheat cultivars (Triticum aestivum cv Carazinho, Teal, Lance, Warigal, Isis, Maringa, and BH1146) grown on gravel in solution culture for 30 days. Profiles were simple, consisting of only malic, aconitic, and citric acids, with levels of each acid for all varieties falling within the range 2-5 mumol/g fresh tissue. Storage of samples led to a large increase in sampling error and increased the amount of extractable citric acid.

Calibration↗
PubMed1984

Purification to homogeneity and partial characterization of a 56,000-dalton protein phosphatase from rabbit reticulocytes.

A 56,000-Da peptide with inherent protein phosphatase activity was isolated from the postribosomal supernatant fraction of rabbit reticulocytes. The peptide appears to form complexes with other proteins that are present in crude fractions. It exhibits atypical retention on steric exclusion columns during high performance liquid chromatography, an unusual characteristic that facilitated its isolation. The protein phosphatase activity of the 56,000-Da peptide is dependent on Mn2+ ions, but is not activated by either the FA, ATP/Mg2+ protein phosphatase activator system or by proteolysis. The protein phosphatase activity of the peptide is increased 3-fold or more by the antigen peptides described in the accompanying paper (Fullilove, S., Wollny, E., Stearns, G., Chen, S.C., Kramer, G., and Hardesty, B. (1984) J. Biol. Chem. 259, 2493-2500).

Amino Acids↗
PubMedDate not supplied

Cyclo-oxygenase blockade abrogates the endotoxin-induced increase in Na(+)-dependent hepatic amino acid transport.

BACKGROUND: Endotoxemia is characterized by a marked increase in the uptake of amino acids by the liver, but the regulation of this response has not been fully elucidated. In the current study, we investigated the potential role of prostaglandins as mediators of this response. We examined the in vivo effects of the anti-inflammatory agent ketorolac, a cyclo-oxygenase inhibitor that blocks prostaglandin synthesis, on hepatic amino acid transport activity in endotoxin-treated rats. METHODS: We assayed the activities of the Na(+)-dependent transport systems A and N in hepatic plasma membrane vesicles prepared from endotoxemic rats that were pretreated with ketorolac or vehicle. Hepatic plasma membrane vesicles were prepared by differential centrifugation, and the transport of [3H]glutamine (system N) and [3H]2-methylamino-isobutyric acid (system A) was assayed. Hepatic plasma membrane vesicles were also prepared from normal rats that received prostaglandin E2, and glutamine and MeAIB transport were measured. RESULTS: Endotoxin treatment resulted in a twofold to threefold increase in Na(+)-dependent amino acid transport activity in hepatic plasma membrane vesicles secondary to an increase in the transport Vmax, which was consistent with the appearance of increased numbers of corresponding transporter proteins in the hepatocyte plasma membrane. Pretreatment with ketorolac almost completely abrogated the endotoxin-induced increase in hepatic amino acid transport. Administration of prostaglandin E2 to normal rats resulted in a statistically significant increase in glutamine and alanine transport by hepatic plasma membrane vesicles prepared from these animals. CONCLUSIONS: Prostaglandins play a key role in mediating the accelerated hepatic amino acid transport that occurs during endotoxemia.

Alanine↗
PubMedDate not supplied

Evaluation of the efficacy of Eimeria maxima oocyst immunization with different strains of day-old broiler and roaster chickens.

The performances of three different strains of male and female broiler or roaster chickens immunized at 1 day of age with a drug-resistant field isolate of Eimeria maxima were evaluated in battery and floorpen immunization trials. No difference in immunization potential was seen between these strains or sexes of day-old chickens immunized with 2500 oocysts/bird of E. maxima and challenged at 10 days of age with 25,000 oocysts/bird of the same isolate in two separate battery trials. All immunized birds showed significant protection for the parameters of weight gain and midintestinal lesion scores at 7 days post challenge (PC) when compared with nonimmunized challenged controls. In two separate floorpen trials, one broiler bird strain (designated strain 2) immunized by the same procedure and challenged at 21 days of age with the equivalent of 25,000 oocysts/bird of the same isolate showed significant protection for weight gain and lesion scores at 7 days PC when compared with nonimmunized controls. Birds in these same floorpen experiments immunized with E. maxima and then fed three different anticoccidial shuttle diets (narasin and nicarbazin 90 grams/ton (g/t) in starter feed and narasin 72 g/t + roxarsone 45.4 g/t in grower feed; nicarbazin 113 g/t in starter feed and narasin 72 g/t + roxarsone 45.4 g/t in grower feed; and monensin 100 g/t in starter and grower feed) showed no interference with elicited immunity with E. maxima challenge for the same parameters measured. No significant difference was seen between any floorpen immunized bird groups for total weight gain at trial terminations (49 days of age).

Animal Feed↗