Search PubMed⌕ Search

Biomedical subjects

J W Patterson

Publications and source records attributed to J W Patterson.

14 recordsLinked to original sources
PubMed1992

D600 increases the resistance associated with the equatorial potassium current of the lens.

The effects of D600, the methoxy analog of verapamil, on a pCMPS system were studied. A major effect of D600 is to increase the resistance associated with the equatorial potassium current of the lens. The increase in resistance is statistically significant at concentrations above 200 microM. At concentrations of 25-50 microM, D600 counteracts the decrease in resistance produced by binding sulfhydryl groups with 1 microM pCMPS. This effect is similar to that produced by quinine and by a calcium-free medium, and is attributed to the prevention of an increase in the calcium-dependent conductance produced by pCMPS.

4-Chloromercuribenzenesulfonate↗
PubMed1992

Ultrastructural changes in acquired perforating dermatosis.

We performed ultrastructural studies of skin lesions in seven adults with acquired perforating dermatosis. Three of the patients had diabetes mellitus and two were undergoing hemodialysis. Lesions in an early stage showed exocytosis of inflammatory cells and alteration of elastic fibers. Lesions in an intermediate stage featured discontinuities of the basement membrane and aggregates of electron-dense material lateral to the perforated focus, together with dermal edema, scattered macrophages, and densely aggregated collagen fibers that focally filled the papillary dermis. Later-stage lesions showed fibroblasts in the dermis and degenerated elastic fibers within transepidermal channels. In most cases there was a single large epidermal channel lined by flattened epithelial cells, and containing a variety of cellular and extracellular materials. Small "secondary" channels without abnormal keratinization were also observed within the epidermis. The findings suggest that altered keratinization is limited to the immediate vicinity of well-formed transepidermal channels, and that exocytosis of inflammatory cells and alterations of elastica are early and possibly key changes in lesion development. The unexpected discovery of hair fragments in one case suggests that curled hairs may play a role in the pathogenesis of some cases of acquired perforating dermatosis.

Adult↗
PubMed1979

Localized tick bite reaction.

A woman presented with a localized tick bite reaction. The tick (Amblyomma americanum, the "lone star" tick) was still attached to the erythematous, indurated skin of the upper back. After several unsuccessful attempts at removal, a punch biopsy was performed, and the resultant histologic sections incorporated both tick and involved skin. The various systemic and localized tick bite reactions are discussed, as are the diagnostic dilemmas which may arise when the organism is no longer present. Punch biopsy is suggested as an effective means of removing the organism.

Aged↗
PubMed1977

Pterygium inversum unguis-like changes in scleroderma. Report of four cases.

During an 18-month period, four patients with scleroderma were found to have nail findings suggestive or pterygium inversum unguis, a recently described condition. In the same time period, two other examples of the disorder were seen. Pterygium inversum unguis-like change may represent an additional nail sign in scleroderma. There are possible mechanisms for its development in patients with Raynaud's phenomenon, connective tissue diseases, or peripheral vascular disease.

Adult↗
PubMed1976

The effect of tonicity on lens volume.

Rat lenses incubated in hypotonic medium adapted to the medium by first undergoing osmotic swelling and then returning after 1 to 2 days to their originial volume. Two processes--osmotic swelling and volume regulation--appear to be working simultaneously. The former is indicated by a decrease in the concentration of cell potassium to the expected level and the latter by a limitation of lens volume associated with a decrease in the potassium content of the lens. These findings are consistent with those observed in other types of cells and may be of significance in understanding the etiology of cataracts.

Animals↗
PubMed1975

A comparison of Rhodnius prolixus, Triatoma infestans and Panstrongylus megistus in the xenodiagnosis of a chronic Trypanosoma (schizotrypanum) cruzi infection in a rhesus monkey (Macaca mullatta).

Fifth instar Rhodnius prolixus, Triatoma infestans and Panstrongylus megistus were fed on a rhesus monkey (Macaca mullatta) with a chronic infection of Peru strain Trypanosoma cruzi and examined 30 days later for the presence of trypanosomes in the rectum. No correlation could be demonstrated between either blood meal size or sex and the subsequent development of a rectal infection with T. cruzi. As T. infestans and P. megistus were more highly infected than R. prolixus in terms of both percentage infected and degree of infection, the two former species can be regarded as more suitable for the xenodiagnosis of this particular strain of T. cruzi in M. Mullatta.

Animals↗
PubMedDate not supplied

Disposition of flunisolide in the rat, mouse, dog, rhesus monkey, and cynomolgus monkey.

Flunisolide (6 alpha-fluoro-11 beta, 16 alpha, 17 alpha, 21-tetrahydroxypregna-1,4-diene-3,20-dione 16,17-acetonide) administered as a single iv or oral dose to rats, mice, dogs, rhesus monkeys, and cynomolgus monkeys had a plasma t 1/2 of 1-3.5 hr and was eliminated mainly via the bile. After iv administration of 14C-labeled flunisolide, radioactivity was widely distributed into tissues and organs. The apparent volume of distribution of flunisolide in these five species was 3.0-8.0 liters/kg. A major metabolite isolated from rhesus monkey urine was shown to be 6 beta, 11 beta, 16 alpha, 17 alpha, 21-pentahydroxypregna-1,4-diene-3,20-dione 16,17-acetonide (6 beta-OH metabolite). Free 6 beta-OH metabolite was a major radioactive entity detected in urine of all species given radiolabeled flunisolide, whereas flunisolide conjugated with glucuronic acid and/or sulfate was a major metabolite detected in the bile of rats, dogs, and cynomolgus monkeys. Following the oral administration of radiolabeled flunisolide, radioactivity was rapidly and efficiently absorbed in all species, but in the rhesus and cynomolgus monkeys most of the plasma radioactivity was due to the 6 beta-OH metabolite and to water-soluble conjugates, suggesting extensive first-pass metabolism of flunisolide.

Animals↗