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Biomedical subjects

D Phillips

Publications and source records attributed to D Phillips.

At least 145 records · Page 8Linked to original sources
PubMed1989

Diurnal variation in vision after radial keratotomy.

We tested eight patients who had undergone radial keratotomy with regard to refraction, keratometry, corneal thickness, and intraocular pressure one to two weeks after surgery. Patients were examined immediately after eye-lid opening at 7:30 A.M. and again at 4:00 P.M. The contralateral eye was used as a control. The treated eye was 1.48 +/- 0.24 diopters (mean +/- S.E.M.) more hyperopic at the morning examination compared to the afternoon visit, whereas the control eye had an insignificant shift (0.16 +/- 0.06 diopters). The treated eye was significantly flatter (1.37 +/- 0.19 diopters) in the morning than in the afternoon when compared to the control eyes, which were only 0.11 +/- 0.09 diopter flatter. The intraocular pressure changed insignificantly in both the treated and control eyes (-0.5 +/- 0.53 mm Hg and -0.5 +/- 0.84 mm Hg, respectively). The mean morning corneal thickness was significantly greater (5.7%) than the afternoon thickness when compared to the controls (1.7% morning increase in thickness). These data suggest that diurnal variation in corneal thickness after radial keratotomy plays a role in diurnal variation of vision in the early postoperative period.

Adult↗
PubMed1989

What are the ideal photoproperties for a sensitizer?

For effective photosensitization of malignant tumours, a sensitizer should exhibit appreciable absorption at red to near-infrared wavelengths and generate cytotoxic species via oxygen-dependent photochemical reactions. These photosensitization mechanisms rely on the excitation of the sensitizer from its electronic ground state to the fluorescent singlet state, which is in turn transformed into the longer-lived triplet state. Efficient formation of this metastable state is required because it is the interaction of the triplet state with tissue components that generates cytotoxic species such as singlet oxygen. Measurement of fluorescence provides a useful means of probing the sensitizer, particularly because detection sensitivities for both the triplet state and the cytotoxic singlet oxygen are much lower. With the development of chemically well-defined sensitizers, in vivo fluorescence detection has the potential to provide quantitative assessment of photoactive sensitizer distributions. The reactive properties of sensitizer triplet states and species such as singlet oxygen can result in significant sensitizer photodegradation, which may appear undesirable but can be exploited in vivo under certain conditions.

Photochemistry↗
PubMed1989

Outbreak of nosocomial Flavobacterium meningosepticum respiratory infections associated with use of aerosolized polymyxin B.

Flavobacterium meningosepticum is an uncommon cause of adult nosocomial infection. On a medical/surgical intensive care unit we recently encountered an adult outbreak of respiratory colonization and infection caused by this organism, which was associated with the prophylactic use of aerosolized polymyxin B that had been used in an attempt to abort an outbreak of infection caused by highly resistant strains of Pseudomonas aeruginosa. Twenty isolates (95% from respiratory secretions) of F. meningosepticum from nine persons were identified during a 2 1/2-month period. No environmental source has been identified to date. Pneumonia developed in five patients, and two deaths associated with this organism occurred. All isolates were sensitive to ciprofloxacin; none were sensitive to other antibiotics tested, including third-generation cephalosporins, aminoglycosides, erythromycin, trimethoprim-sulfamethoxazole, antipseudomonal penicillins, aztreonam, and imipenem/cilastatin. Two patients with nosocomial pneumonia were successfully treated with oral ciprofloxacin. F. meningosepticum may emerge as an important pathogen if prophylactic use of polymyxin B becomes more widespread. Ciprofloxacin may become the agent of choice for treatment of this organism.

Administration, Inhalation↗
PubMed1989

Federal programs affecting rural perinatal health care.

Access to perinatal health care in rural communities often depends on such factors as the availability, cost, and acceptability of services. The federal government has been providing rural perinatal health care both directly and indirectly, through grants for service delivery or research and through direct payment for service. The various federal programs supporting perinatal health care in rural communities are described, and what may need to be done in the future is discussed.

Female↗
PubMed1989

Use of charge coupled device camera for imaging of intracellular phthalocyanines.

A highly sensitive charge-coupled device (CCD) camera, linked to a computerized image processor, has been used to obtain fluorescence images of chloro-aluminum sulfonated phthalocyanine (ClAlSPc), and its mono- to tetra-sulfonated constituents, in cells recovered from the peritoneal cavity of dye-treated mice. Immunofluorescence and cytochemistry showed that cells which preferentially took up ClAlSPc and its sulfonated species were predominantly of the monocyte-macrophage series. While this technique may be of use in determining the nature of those cells capable of taking up light sensitive dyes and, perhaps, the intracellular location of such agents, the possibility that photoinactivation by dye aggregation could reduce the sensitivity of this procedure is discussed.

Animals↗
PubMed1989

Erythroderma from systemic contact dermatitis: a complication of systemic gentamicin in a patient with contact allergy to neomycin.

A patient who was sensitive to potassium dichromate and neomycin showed a universal exfoliative erythroderma following intravenous gentamicin therapy. When his ear canals were later treated with a neomycin-containing topical medication, he reacted so severely that the skin of his ears was temporarily depigmented. Withdrawal of aminoglycoside antibiotics along with use of a topical steroid preparation under occlusion brought the eruption under control. Since approximately half of the persons with contact allergy to neomycin will also react to gentamicin, it seems unwise to treat such patients with other intravenous aminoglycosides that are closely related chemically. In our patient, multiple patch tests to other aminoglycosides caused positive reactions to all reagents containing a deoxystreptamine ring, but there was no reaction to streptomycin, which lacks that structure.

Aged↗
PubMed1989

Anabolic steroid legislation Act 249 of 1989.

Health care professionals are urged to be alert to the potential for adverse effects common to the use of anabolic steroids by athletes and others, including high school and college students active in varsity sports or body lifting. The Department of Health, Division of Pharmacy Services and Drug Control asks for cooperation and assistance in helping combat the illegal diversion by physicians and pharmacies of these hazardous drugs and to ensure that these drugs are available to patients only through legitimate channels. Act 249 of 1989 was enacted to prevent the distribution and use of illegal anabolic steroids and growth hormones and for purposes of defining and setting penalties for the illegal use.

Anabolic Agents↗
PubMed1989

Factors influencing changes in obstetric care provided by family physicians: a national study.

In an effort to determine the factors underlying changes in obstetric practice by family physicians, a random sample of 505 residency-trained family physicians was surveyed by mailed questionnaire. Of the 329 who responded, 65% had at some time practiced obstetrics, but only 45% were practicing obstetrics at the time of the survey. Rising malpractice insurance premiums and fear of lawsuit were factors most likely to influence a family physician's decision to cease obstetric practice. Lifestyle concerns and the number of obstetricians practicing in the area were also important factors for all family physicians. Important differences were found between family physicians who never delivered babies and those who had at some time practiced obstetrics. Family physicians who have given up obstetric practice were found to feel well trained and competent in this practice. Since changes in obstetric practice patterns have had an adverse effect on the obstetric care of women in rural areas and for the medically indigent, these findings have important public health implications.

Attitude of Health Personnel↗
PubMed1989

Highly sensitive assays of autoantibodies to thyroglobulin and to thyroid peroxidase.

These highly sensitive assays are based on the interaction between thyroid autoantibodies and 125I-labeled autoantigens. Serum samples are incubated with labeled thyroid peroxidase (TPO) or thyroglobulin (Tg) to allow the formation of antibody-labeled antigen complexes. The complexes are then precipitated by addition of solid-phase Protein A. In the presence of high concentrations of TPO antibody or Tg antibody, more than 50% of the respective labeled antigen was precipitated, whereas only 1-2% was precipitated in the absence of autoantibody. Interassay CVs were 3.2% and 5.7%, respectively, for the anti-TPO and anti-Tg assays. There was no cross-reactivity between Tg antibody and TPO antibody. Results correlated highly significantly with results from other assay systems based on antigen-coated cells or plastic supports, but the assays described here were considerably more sensitive. Scatchard analysis of the assay data provided information on the affinity and serum concentration of TPO autoantibodies (ka approximately 10(9) L/mol and concentrations up to 1 g/L) and Tg autoantibodies (ka approximately 4 x 10(10) L/mol and concentrations up to 1 g/L). Overall, these assays provide a sensitive, precise, and convenient system for measuring and investigating the properties of thyroid autoantibodies.

Antibody Specificity↗
PubMed1988

An unusual cause of hip pain in a child.

In this perplexing case, a child with signs of apparent hip pain was treated for a sewing needle embedded in the sole of the foot. The diagnosis of foreign body easily could have been missed, because the external signs were minimal and the clinical findings indicated hip disease. However, the child's extreme distress seemed inconsistent with the initial normal findings. Only reexamination and looking beyond the obvious led to the diagnosis.

Child, Preschool↗
PubMed1988

Chlamydia screening.

Explore the source record for details and available documents.

Chlamydia Infections↗
PubMed1988

Chromosomal localization of the genes for the vitronectin and fibronectin receptors alpha subunits and for platelet glycoproteins IIb and IIIa.

The integrins, a family of related membrane receptors involved in cell-cell and cell-matrix interactions, are heterodimeric complexes of alpha and beta subunits. To begin to understand the evolution of these complexes, we studied the genomic organization of several alpha and beta integrin subunits. Using both somatic cell hybrids and an in situ hybridization technique, we have determined the chromosomal location of the genes for the alpha subunits of the vitronectin receptor (VNR alpha), the fibronectin receptor (FNR alpha), and for the alpha subunit of the platelet glycoprotein IIb/IIIa complex, GPIIb. In addition, we have determined the chromosomal location of the gene for the beta subunit of the GPIIb/IIIa heterodimer, GPIIIa. Our studies indicate that the alpha subunits do not localize to a single locus, but that each is found on a different chromosome. The gene for VNR alpha is located on chromosome 2, the gene for FNR alpha is on chromosome 12q11----13, and the gene for GPIIb is on chromosome 17q21----23. In contrast to the chromosomal dispersion of the alpha subunits, the genes for GPIIb and GPIIIa are physically close, with the gene for GPIIIa also located on chromosome 17q21----23. These studies indicate that the genes for the alpha subunits of the integrin family have been dispersed during evolution while GPIIb and GPIIIa are in close physical proximity. This physical proximity of GPIIb and GPIIIa may be involved in the concurrent expression of these proteins by megakaryocytes, and may result in linkage disequilibrium between these two genes, which would limit the use of restriction length polymorphisms in linkage studies of GPIIb/IIIa abnormalities in small kindreds.

Animals↗
PubMed1988

Failure of gonadotropin therapy secondary to chorionic gonadotropin-induced antibodies.

Seventeen years after first receiving treatment with hCG (at age 8 yr), a man with hypogonadotropic hypogonadism no longer responded to gonadotropin therapy. He had received hCG for 6 months when he was 8 yr old, from age 18-21 yr and from age 21-25 yr, when the resistance developed. Anti-hCG antibodies were found in his serum. Three sequential treatment regimens were tried to obviate the effect of these antibodies. 1) hCG treatment (2000 IU, three times per week) concomitant with weekly plasmapheresis (since the patient's response to an hCG challenge test was improved after a reduction of antibody titer by plasmapheresis) resulted in only a temporary increase in testosterone production. 2) Treatment with human (h) LH (400 IU/week) and hFSH (25 IU/week) was used because of the low cross-reaction of the antibodies with hLH and a response to a hLH-challenge test. This treatment maintained serum testosterone levels within the normal range for long periods, but had to be discontinued when the supply of hLH was exhausted. 3) Pulsatile LHRH administration (25 ng/kg, sc, every 2 h) for 2 months did not induce the release of pituitary gonadotropins. These results indicated that 1) conventional hCG treatment was impaired by antibody-induced changes in the kinetics of hCG after its im administration; 2) hLH was an effective substitute for hCG, and the combined hLH-hFSH administration initiated a moderate amount of spermatogenesis; and 3) the patient differs from most individuals with hypogonadotropin hypogonadism in that he did not have normal responses to repetitive LHRH administration.

Antibodies↗
PubMed1988

Sensitivity of the skin of different mouse strains to the promoting effect of 12-0-tetradecanoyl-phorbol-13-acetate.

The sensitivity of the skin of Swiss DBA/2 and C57B1/6 mice was compared in two-stage carcinogenicity experiments. Groups of 30 mice were treated once with 7,12-dimethylbenz(a)anthracene (DMBA) (50 micrograms/mouse) which was applied to the shaved dorsal skin as initiator and, starting one week later, 12-0-tetradecanoyl-phorbol-13-acetate (TPA) was applied thrice-weekly at doses of either 0.04, 0.16 or 0.64 micrograms/mouse to the areas of initiated skin. Other groups of mice were similarly treated with TPA (0.64 micrograms) alone. The times at which papillomas and carcinomas first appeared were recorded. Overall the results show, in terms of the numbers of animals with tumours, the total numbers of tumours produced and the numbers of malignant tumours formed all in dose-response relationship, that the Swiss mice were the most sensitive and the B57B1/6 mice the least sensitive to the tumour-promoting effects of TPA with the DBA/2 mice occupying and intermediate position. This relationship also held in the control groups that were treated with TPA alone.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Metabolic and thermoregulatory consequences of social behaviors between Microtus townsendii.

1. Townsend voles responded to each other by raising their core temperatures. 2. Increments of temperature increases that accompanied hostile reactions between voles, were proportional to the intensity of the behavioral displays. 3. Amicable behaviors (huddling) were also associated with higher body temperatures that were proportional to group size. 4. Huddling voles conserved metabolic energy expenditure by reducing their metabolic rates and thermal conductances. 5. Such conservation required 1 or more days of amicable behavior to develop, and to be reversed. 6. The degree of metabolic rate reduction that accompanied amicable huddling behavior and the associated reduction of thermal conductance was independent of group size.

Animals↗
PubMed1987

Cellular and protein changes in bronchial lavage fluid after late asthmatic reaction in patients with red cedar asthma.

To investigate the sequence of cellular and protein changes after a late asthmatic reaction (LAR), bronchial lavage was carried out in 44 patients with red cedar asthma at different time intervals after bronchial challenge with plicatic acid. The results were compared to five patients with red cedar asthma who became asymptomatic after removal from exposure to red cedar for more than 2 months and 31 healthy subjects without asthma. The LAR was found to be associated with an increase in eosinophils in the lavage fluid, an increase in sloughing of bronchial epithelial cells, and an increase in degenerated cells consisting mainly of degenerated epithelial cells and alveolar macrophages. There was an increase in vascular permeability as reflected by an increase in albumin in the lavage fluid. Although there was a slight but significant increase in neutrophils 48 hours after bronchial challenge, neutrophil infiltration was not a prominent feature earlier. The potential role of loss of epithelial cells to account for an increase in nonspecific bronchial hyperresponsiveness after an LAR was discussed.

Adult↗