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Biomedical subjects

J M Thompson

Publications and source records attributed to J M Thompson.

At least 199 records · Page 11Linked to original sources
PubMed1985

Interaction of anticonvulsants and oral contraceptives in epileptic adolescents.

Oral contraceptives are in widespread use, and are commonly prescribed for contraception in patients taking other medications. An example of this is the concomitant use of oral contraceptives and anticonvulsants in epileptic patients. This combination creates a potential for drug interactions which may alter the efficacy of both medications. An apparent interaction between oral contraceptives and anticonvulsants was observed in this study of epileptic adolescent females. This interaction was evidenced by menstrual irregularities which occurred in 65% (7 of 11) of adolescents on both medications concomitantly. The frequency of irregularity was significantly higher in these adolescents when compared to adolescents on either medication alone. Irregularities appeared to be alleviated by increasing the strength of the oral contraceptive, and although a concern, the increased dosage did not affect seizure control.

Adolescent↗
PubMed1985

A longitudinal study of the detection of otitis media in the first two years of life.

A number (210) of children were followed longitudinally through the first two years of life with pneumatic otoscopy and electroacoustic immitance, tympanometry, at every physician encounter. Tympanometry proved to have a high predictive value (86%) for detecting normal ears but relatively poor predictive value (58%) for detecting abnormal ears when utilized as a routine screening procedure with every clinic visit. In part the tympanometrically abnormal ears which appeared normal in otoscopic exam were temporally related to recent episodes of otitis and concurrent upper respiratory congestion, but many were unrelated to detectable middle ear pathology. These observations detract from the utility of tympanometry as a screening tool for middle ear pathology.

Acoustic Impedance Tests↗
PubMed1985

Biochemical and physiochemical characteristics of a pre-B cell stimulating factor produced by the plasmacytoma cell line LICR LON HMY2.

We have characterized the pre-B cell colony stimulating activity (pre-B cell CSA) from LICR LON HMY2 conditioned medium (CM) by a variety of biochemical techniques. Pre-B cell CSA was found to be associated with a heat stable glycoprotein which has an isoelectric point of 8.3 and a mol. wt, as determined by polyacrylamide gel electrophoresis, of 28-32 kD. The relationship of this activity to previously described factors acting on cells of the B cell lineage is discussed.

B-Lymphocytes↗
PubMed1985

Human B cell colony growth from pre-B cells in vitro.

We describe a simple one-step technique for the growth of human B cell colonies in semi-solid agar in vitro. This method used conditioned medium from the human plasmacytoma cell line LICR-LON-H My 2 as a source of stimulating activity. A linear relationship exists between the number of B cells seeded and the number of colonies formed (r = 0.95). Most colony forming cells, approximately 1 in 500 of B cells seeded, lack surface immunoglobulin, possess Fc receptors and mark with the Leu 12 monoclonal antibody. Cells within developing colonies are found to have cytoplasmic IgM, IgA and IgG depending on the length of time in culture.

B-Lymphocytes↗
PubMed1985

Detection and partial characterization of human B cell colony stimulating activity in synovial fluids of patients with rheumatoid arthritis.

The joint fluids of 37 patients with rheumatoid arthritis, eight patients with traumatic injuries to their joints, two patients with Reiter's syndrome and three patients with psoriatic arthritis were tested for the presence of B cell colony stimulating activity (B cell CSA). B cell CSA was found in all of the joint fluids from the patients with rheumatoid arthritis but in none of the joint fluids from patients with traumatic injuries to their joints or in the joint fluids from the patients with Reiter's syndrome. A trace of B cell CSA was found in the joint fluid of one of the three patients with psoriatic arthritis. There was a positive correlation (r = 0.796) between the amount of rheumatoid factor present in the joint fluids and the titre of B cell CSA. This correlation was highly significant (P less than 0.001). The B cell CSA was localized to component(s) with molecular weight ranges 115-129 kD and 64-72 kD and an isoelectric point of 6.8. Its activity was sensitive to reduction with 2-mercaptoethanol and to the oxidising action of potassium periodate.

Adult↗
PubMed1984

Age-related decrease in apomorphine modulation of acetylcholine release from rat striatal slices.

Release of [3H]acetylcholine ( [3H]ACh) was assessed in striatal slices from mature, middle-aged and senescent Wistar rats 8, 12 and 24 months of age, respectively. There was an age-related decline in basal release of [3H]ACh as a function of age which was correlated with a decline in accumulation of [3H]ACh. However, the most striking finding was the failure of apomorphine to inhibit KCl-induced [3H]ACh release in the senescent (24 months) animals. Striatal dopaminergic receptor losses in senescence apparently produce several subsequent changes in striatal function which ultimately result in the decline of motor-behavioral function.

Acetylcholine↗
PubMed1984

Blockers of calcium permeability inhibit neurite extension and formation of neuromuscular synapses in cell culture.

Growth of neurites from trypsin-dissociated retinal neurons from chick embryos is very sensitive to the extracellular calcium concentration. Blockers of calcium permeability such as Co2+, Mn2+, La3+ and nitrendipine, when added to dissociated neurons, decrease the fraction of cells that extend neurites and the rate of neurite growth without influencing cell-substratum adhesion or survival capacity. Inhibition is concentration dependent, is related to the age of the donor chick embryo and can be prevented by increasing the extracellular calcium concentration. 50% inhibition in 8-day neurons is produced by 120 microM Co2+, 250 microM Mn2+, 50 microM La3+ and 10 microM nitrendipine in medium containing 1.8 mM Ca2+. Inhibition of neurite extension is accompanied by a concentration dependent inhibition of synapse formation between retinal neurons and muscle cells in culture, as determined by intracellular recording. 50% inhibition in the fraction of innervated myotubes is produced by 0.4 mM Co2+ and 4 mM Mn2+. These results suggest that: (1) a voltage-dependent calcium flux is a signal not only for growth cone expansion but also for neurite extension in primary dissociated neurons; and (2) that neurite extension is a prerequisite for synaptogenesis between neurons and muscle cells in culture.

Age Factors↗
PubMed1984

Anaplastic myeloma in systemic lupus erythematosus.

We describe a patient with systemic lupus erythematosus who developed an unusual form of anaplastic myeloma. Possible relationships between the two disease, and the role played by immunosuppressive therapy, are discussed.

Female↗
PubMed1983

Pneumococcal vaccine in normal children. Primary and secondary vaccination.

A pneumococcal polysaccharide vaccine containing 50 micrograms of each of 14 pneumococcal types was administered to 79 children 2 to 5 years of age. In earlier studies, 52 of these children had received pneumococcal vaccine; 27 had received a placebo. Local reactions were significantly greater in the reimmunized group. Antibody response to the vaccine was similar in both groups. Mean fold rises to most vaccine components were at least twofold. The response to specific pneumococcal types was unrelated to the frequency with which each type causes illness. Response to type 6 continued to be poor for children up to age 5 years. A vaccine with improved immunogenicity must be developed before widespread use in normal children is advocated. However, the 14-valent pneumococcal polysaccharide vaccine currently available is moderately immunogenic in children by age 2 years and should be given to patients with increased risk of pneumococcal illness at that time.

Age Factors↗
PubMed1982

Increase in acetylcholine release from chick embryo retina during development.

The release of [3H]acetylcholine (ACh) from 6-, 8-, 10-, 12-, 14- and 16-day chick embryo neural retina layers was determined using a perfusion system to collect the released neurotransmitter. After labeling the tissue with [3H]choline, samples of [3H]ACh released before and after stimulation by 80 mM KCl or 5 mM glutamate were collected and analyzed. The results showed a developmental increase in both basal and stimulated release. The increase was not caused by changes in [3H]choline uptake or total [3H]ACh synthesized which did not increase with developmental age. The developmental increase is correlated with the time of formation and maturation of retinal cholinergic synapses in ovo, but is not correlated with the developmental decrease in cholinergic synapses formed by retina neurons with striated muscles in vitro.

Acetylcholine↗
PubMed1982

Clinical evaluation of moxalactam.

Moxalactam was administered intravenously or intramuscularly or both in doses of 1 to 12 g/day to 45 patients with clinically significant infections (17 soft tissue or bone, 9 pleuropulmonary, 9 septicemic, 6 urinary tract, and 4 intraabdominal infections). Mean 0.5-h postinfusion levels were 105 micrograms/ml for a 4.0-g dose, 44.7 micrograms/ml for a 2.0-g dose, and 18 micrograms/ml for a 1.0-g dose. We identified 28 isolates of Enterobacteriaceae, 10 Pseudomonas aeruginosa isolates, 9 Staphylococcus aureus isolates, and 15 anaerobic bacterial isolates. A total of 15 patients were clinically cured, 8 patients improved, 13 patients improved initially but suffered subsequent relapses or superinfections, and 10 patients failed therapy. Toxicity was generally minimal (reversible eosinophilia, and mild liver function abnormalities, and elevated prothrombin time). The selection or emergence of resistant organisms in 17 patients during treatment (particularly Pseudomonas, enterococci, and Candida) was a disturbing feature of therapy. Our results were generally favorable, considering the complicated underlying medical problems of this group of patients.

Adult↗
PubMed1982

Attachment, survival and neurite extension of chick embryo retinal neurons on various culture substrates.

Chick embryo retina neurons in culture extend neurites and form synapses. Seven different culture substrates were compared to determine which culture surface would produce the best neuronal survival and neurite extension. The order of survival of retina neurons during 7 days of culture is salt-precipitated collagen greater than ammoniated collagen greater than fibronectin greater than air-dried collagen = polylysine greater than tissue culture plastic greater than polyornithine. Similarly, salt-precipitated collagen allowed the greatest number of cells to extend neurites. The amount of neuronal aggregation and nonneuronal cell growth also varied with the substrate. Nonneuronal cell growth promoted neuronal growth and neurite extension on several substrates.

Animals↗