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Biomedical subjects

J D Phillips

Publications and source records attributed to J D Phillips.

At least 73 records · Page 4Linked to original sources
PubMed1990

Pharmacokinetics of lithium in patients treated with controlled release lithium formulations.

There has long been discussion as to the relative merits of the lithium formulations available in the UK. Two of these have been shown to exhibit similar pharmacokinetics in normal volunteers and both are now marketed as controlled release formulations. In this study the serum lithium profiles of these formulations were compared in patients at two centres during the first 4 h after the dose, and at 24 h. We were unable to show any significant difference between the formulations in respect of maximum serum lithium concentrations or the concentration at each time point.

Adult↗
PubMed1989

Financial analysis of an inner-city helicopter service: charges versus collections for patients transferred from another acute care facility.

Emergency helicopter services provided by trauma centers are now being perceived as contributing to the financial burden of the hospital because of recent changes in trauma reimbursement under the Medicare Prospective Payment System (PPS) and because of the general perception that collection rates are lower among trauma patients. The use of helicopters to transfer patients from one acute care facility to another may also be concentrating the patients with low collection rates at the receiving hospital. We examined retrospectively the demographic and clinical factors associated with the collection experience in a series of 288 trauma patients transferred by helicopter from another acute care facility to an inner-city hospital. Factors affecting payment at 180 and 360 days included patient age, insurance class, discharge status, and size of the hospital charge. As long as reimbursement continues to be cost-based for nonMedicare patients, collection rates remain an important consideration in determining the financial viability of using helicopters to transfer patients.

Accounting↗
PubMed1989

Financial analysis of an inner-city helicopter service: charges versus collections.

Trauma centers are now being perceived as financial burdens because of recent changes in trauma reimbursement for the Medicare Prospective Payment System population and the perception that collection rates are lower among trauma patients. We examined the demographic and clinical factors associated with the collection experience in a series of 114 trauma patients transferred by helicopter from the accident site to an inner-city trauma center. Factors affecting payment at 30, 60, 90, and 180 days included patient age, insurance class, and discharge status. While not as high as the collection rate for the facility as a whole, we found an average 71.2% collection rate for trauma patients at 180 days. As long as trauma reimbursement continues to be cost based for nonMedicare patients, collection rates remain an important consideration in determining the financial viability of trauma centers.

Accounting↗
PubMed1987

Clonal heterogeneity of anti-AKR/gross leukemia virus cytotoxic T lymphocytes. Evidence for two distinct antigen systems.

AKR/Gross leukemia virus-induced tumor reactive cytotoxic T lymphocyte (CTL) clones were derived from C57BL/6 spleen cells. Analysis of their specificity pattern was performed by using a panel of target cells such as E male G2 and AKR.H-2bSL1 (susceptible tumors to polyclonal anti-AKR/Gross virus CTL), and cl. 18-5 and cl. 18-12 (insusceptible variant sublines derived from AKR.H-2bSL1). Several of these CTL clones were selected for further study. Lysis of Gross cell surface antigen-positive tumor cells by these clones was restricted by the H-2Kb molecule. The cell surface phenotype of these clones was Thy-1.2+, Lyt-2.2+, L3T4-, a phenotype consistent with that of polyclonal anti-AKR/Gross CTL, suggesting that they were of conventional CTL origin. According to their fine specificity pattern, the CTL clones were divided into two major groups (A and B) which were further subdivided into five and three subgroups, respectively. The specificity of group A clones was essentially the same as that of the standard polyclonal CTL population except for a variable level of natural killer-like activity by some of the CTL clones. That is, group A clones did not efficiently lyse the insusceptible variant tumors nor any of Friend-Moloney-Rauscher-positive tumors tested, but they showed strong lytic activity to susceptible tumors and iododeoxyuridine-treated insusceptible variants. Thus, their CTL activity appeared to be strictly directed to Gross cell surface antigen-positive tumors that are susceptible to polyclonal anti-AKR/Gross virus CTL. In contrast, group B clones could lyse both susceptible and insusceptible variant tumors and also a Friend virus-induced tumor (FBL3). Therefore, as defined by these CTL clones, at least two distinct antigenic systems (A and B), each with several antigenic determinants, appeared to be present. Because recent findings suggested that most of the polyclonal anti-AKR/Gross virus CTL activity appeared to be directed to N-ecotropic proviral determinants, we further investigated the nature of these two antigenic systems by use of additional target cells including lipopolysaccharide (LPS)-stimulated spleen cell blasts from AKXL recombinant inbred strains and retrovirus-infected fibroblasts. Group A clones could lyse all LPS blasts derived from AKXL recombinant inbred strains containing the AKV-1 proviral genome, but lysed only very insufficiently or did not lyse AKV-1-negative blasts containing the AKV-3 and/or AKV-4 provirus.(ABSTRACT TRUNCATED AT 400 WORDS)

AKR murine leukemia virus↗
PubMed1987

A note on the use of the Catalasemetre in assessing the quality of milk.

The Catalasemetre, for assessing the quality of raw and pasteurized milk, has been studied. No correlation was found between catalase activity and bacterial counts for farm bulk tank milks within the range 5.2 X 10(2)-5.4 X 10(5) cfu/ml. Similarly, no relation was observed between catalase activity and somatic cell counts of milk (range of counts from 0.08 to 3.5). However, the catalase activity and bacterial count of pasteurized milks which had been pre-incubated at 21 degrees C for 25 h in the presence of crystal violet-penicillin-nisin to inhibit Gram-positive bacterial growth were significantly related. Thus, the use of this pre-incubation procedure coupled with the Catalasemetre to estimate bacterial growth, has potential in assessing the keeping quality of pasteurized milk samples within 25.5 h of production. Results on the thermostability of native milk catalase are also presented.

Animals↗
PubMed1986

Differential induction of H-2K vs H-2D class I major histocompatibility complex antigen expression by murine recombinant interferon-gamma.

The results presented here indicate that recombinant murine interferon-gamma can cause a dramatic differential induction of two distinct class I MHC molecules. Thus, IFN-gamma treatment of the murine leukemia virus (MuLV)-induced AKR SL3 tumor, a cell line that normally expresses moderate levels of class I MHC antigens, resulted in a large increase in H-2Dk expression, but no change or a slight decrease in H-2Kk expression as measured by cytofluorography. Explanations of the selective enhancement of Dk expression based on increased Fc receptor display or differential kinetics of induction were ruled out. The phenomenon was observed over a wide range of doses of IFN-gamma and with two different monoclonal antibodies to Kk, the latter finding making it unlikely that an altered form of the Kk molecule was induced. The same differential induction of the Dk antigen was observed for the LBRM.5A4 tumor cell line. Because LBRM.5A4 is also MuLV+ but of congenic B10.BR (H-2k) origin, these results were consistent with the possibility that such differential induction was associated with the H-2k haplotype and/or MuLV. The implications of these results, as a possible mechanism of tumor cell escape from an immune surveillance system monitored by class I MHC-restricted T cells and as a useful model system to dissect the mechanism of IFN-gamma induction of class I MHC antigens, are discussed.

AKR murine leukemia virus↗
PubMed1986

Estimation of gram-negative bacteria in milk: a comparison of inhibitor systems for preventing gram-positive bacterial growth.

A number of inhibitor systems which have been reported to allow selection of Gram-negative bacteria were tested against Gram-positive and Gram-negative isolates of dairy origin. No one system worked perfectly. A mixture of crystal violet-penicillin-nisin or monensin had least inhibitory effect on Gram-negative isolates whereas Selectocult (a commercially available mixture of Benzalkon A 50% and crystal violet) and sodium deoxycholate were the most effective inhibitors of Gram-positive bacteria. Cetrimide-fucidin-cephaloridine solutions, which have been reported as allowing selective growth of pseudomonads, were not so specific when applied to milk systems.

Animals↗
PubMed1986

Factors contributing to the seasonal variation of Bacillus spp. in pasteurized dairy products.

The seasonal variation in the spoilage of pasteurized products, especially double cream, by spore-forming bacteria was due to a number of factors. By far the most important was the seasonal variation in the types of organisms isolated from raw milks. Psychrotrophic spore-formers predominated in the summer-autumn months and these strains were able to germinate rapidly and grow in refrigerated dairy products. There was evidence that the concentration of one or more factors which promoted germination of psychrotrophic strains of Bacillus spp. in milk was higher during the summer than in the winter. This again may contribute to seasonal differences in spoilage by spore-forming bacteria. Post-heat treatment contamination by spores of Bacillus spp. may also be more prevalent in the summer-autumn period and evidence was obtained that spores associated with post-pasteurization contamination could germinate and grow more rapidly than those introduced into the product from the raw material. Thus, the increased spoilage of pasteurized products by Bacillus spp. observed in the June to October period may be due to a combination of factors. The relative contribution that each makes is not easily resolved.

Animals↗
PubMed1985

Effect of calf weaning age and cow supplementation on cow productivity.

Five years of data were collected on 124 Brangus-type cows to evaluate weaning calves at 8.5 or 10.5 mo of age and winter supplementation of the brood cow with 2.25 kg of molasses daily. Cows with calves weaned at 10.5 mg of age gained 14 kg less weight (P less than .01) during the late nursing period than did cows from which calves were earlier weaned. Age of calf at weaning had no effect on cow reproduction, but calves weaned at 10.5 mo were 2 to 3 d younger (P less than .06) and 5.3 kg lighter (P less than .05) at 8.5 mo of age. During the last 2 mo of nursing, calves weaned at 10.5 mo of age gained 37.2 kg and had a 31.9-kg heavier weaning weight than calves weaned at 8.5 mo of age. Molasses supplementation resulted in differences (P less than .01) in cow weight changes. Cows fed molasses had calving percentages 5 to 7 units higher (P less than .30) than cows not fed molasses. Feeding cows molasses for 145 d throughout the calving and breeding season increased calf weaning weight 7.7 (P less than .02) and 11.2 (P less than .03) kg, respectively, at 8.5 and 10.5 mo of age over the nonsupplemented controls.

Age Factors↗
PubMed1984

Detection of post-pasteurization contamination of cream by impedimetric methods.

Impedimetric methods for evaluating post-pasteurization contamination and shelf-life of cream were assessed. Over 94% of the samples tested were in agreement, using selected cut-offs of 20 h for detection time measured at 21 degrees C with creams containing inhibitors for the growth of Gram positive bacteria on standard plate count agar as growth media, and 3.2 X 10(7) cfu/g for plate counts obtained on cream which had been pre-incubated in the presence of inhibitors for the growth of Gram positive organisms, and on cream stored at 6 degrees C for 7 d. Agreement between the impedimetric method and plate count was not as good if either Brain Heart Infusion or Milk Agar was used in place of Plate Count Agar in the former technique. A poor correlation was obtained between plate count methods for enumerating post-pasteurization contamination and keeping quality with impedimetric measurements on cream alone. It was possible, with a reasonable degree of certainty, to determine if cream had suffered post-pasteurization contamination within 20 h of production.

Bacteria↗
PubMed1984

Use of a personal microcomputer for orthoptic therapy.

Personal microcomputers have become almost commonplace in the last few years. Their great flexibility and ability to present graphic images on demand would seem to make them ideal tools for use in a visual training program. We have written such a program for doing fusional vergence therapy that interacts with the patient and stores the results of the training sessions. The features of the program are described and the results from two patients are summarized.

Accommodation, Ocular↗
PubMed1980

Laboratory evaluation of heparin therapy.

Plasma heparin levels measured using several different methods showed a wide variation in results. In particular an anti-factor Xa clotting technique gave very much higher results than thrombin clotting time and partial thromboplastin time techniques. This was less marked when a synthetic chromogenic substrate assay was used. Possible reasons for these observations and their relevance in the selection of therapeutic ranges are discussed.

Adult↗
PubMed1978

Studies of louping-ill virus (Flavivirus group) in wild red grouse (Lagopus lagopus scoticus).

Studies were made to find evidence of louping-ill virus infection in free-living red grouse and relate this to their breeding success. In areas where ticks were abundant 61 (84%) adult grouse had antibody to the virus compared with 1 (10%) in areas where ticks were relatively scarce. Of 162 chicks tested 25 were shown to be viraemic. Infected chicks were of significantly less weight than comparably aged uninfected birds and the probability that they died was much greater than that of uninfected birds. It is concluded that the relatively poor breeding success in areas of high tick numbers was principally due to infection with louping-ill virus. The susceptibility of the red grouse to infection is discussed.

Animal Population Groups↗