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Biomedical subjects

R L Trelstad

Publications and source records attributed to R L Trelstad.

At least 73 records · Page 4Linked to original sources
PubMed1980

Differences in healing of skin wounds caused by burn and freeze injuries.

Circular, full-thickness dermal burn- and freeze-produced wounds were produced in rats to compare the difference in healing between the two types of thermal injuries. Contraction did not occur in wounds (n = 30) caused by freezing, while burn wounds (n = 30) contracted to less than one-third of original size by 21 days after injury. If the centers of the freeze-produced wounds (n = 12) were excised, contraction would then occur and proceed at the same rate as an open wound. Histologically, the degree of initial tissue destruction by the two types of injuries was similar. The burn wound contained only half the amount of collagen found in the freeze-produced wound. There was a greater and more rapid replacement of collagen in the burn wounds. With both injuries, the highest concentration of collagen was found on the fifteenth day and returned to normal by the twenty-eighth day. The burn wound contained three times the amount of collagen in normal skin, while the freeze-produced wound contained only 1 3/4 times the amount in normal skin. Contraction does not seem to occur in the healing of the freeze-injured skin because the slow removal and replacement of the residual matrix prevents contraction.

Animals↗
PubMed1979

Thorotrast-associated sarcoma of bone: A case report and review of the literature.

An osteosarcoma developed near the right lesser trochanter of a 55-year-old woman. The neoplasm fulfilled the generally accepted criteria for a Thorotrast related malignancy. Strengthening this relationship was the occurrence of the tumor in an unusual location and uncommon age group. Thorium was confirmed both in the tumor and in bone marrow histiocytes by its characteristic x-ray spectrum. Including this case only twelve Thorotrast-associated neoplasms of bone have been reported. The mean latency period after Thorotrast administration was 26 years. Regression analysis revealed that latency period and Thorotrast dose are inversely related. All tumors were reported to be sarcomas. Six osteosarcomas, one fibrosarcoma, one chondrosarcoma, and one undifferentiated sarcoma were proven histologically. All patients, for whom follow-up was given, had died of the tumor. The reasons behind the low frequency of reported Thorotrast-associated bone malignancies may be the low concentration of 232Th and radioactive daughters in bone, long latency period or the general lack of knowledge concerning the possible relationship between Thorotrast and bone tumors. Statistical association between Thorotrast injection and bone sarcoma is shown. The criteria for the diagnosis of Thorotrastosis are discussed as well as the long term deleterious effects. The distribution of Thorotrast within the body is discussed as well as the associated radiographic changes.

Adult↗
PubMed1979

The early limb deformity caused by acetazolamide.

Histologic sections were made of the forelimbs of day 10 to 12.5 embryos removed 3, 16, 30, 36, 42, 45, 63 and 75 hours after the intraperitoneal injection of acetazolamide into C57Bl/6J pregnant females. A postaxial deformity was first visible in the right forelimb of day 10.9 embryos 36 hours after the second dose of acetazolamide 1,000 mg/kg on day 9 of gestation. The deformity was a postaxial deficiency of mesenchyme tissue without any evidence of cell necrosis. The deformity was present before aggregation of mesenchyme cells occurs as the first step in chrondrogenesis. The pattern of cell orientation in the adjacent mesenchyme aggregate of a deformed day 12.5 forelimb was normal. This means that the primary effect of acetazolamide is not on the formation of precartilage aggregates in the postaxial region, but involves other aspects of early limb development.

Acetazolamide↗
PubMed1979

Epithelioid cell cultures from rat small intestine. Characterization by morphologic and immunologic criteria.

Rat small intestinal epithelial cell lines have been established in vitro and subcultured serially for periods up to 6 mo. These cells have an epithelioid morphology, grow as monolayers of closely opposed polygonal cells, and during the logarithmic phase of growth have a population doubling time of 19--22 h. Ultrastructural studies revealed the presence of microvilli, tight junctions, an extensive Golgi complex, and the presence of extracellular amorphous material similar in appearance to isolated basement membrane. These cells exhibit a number of features characteristic of normal cells in culture; namely, a normal rat diploid karyotype, strong density inhibition of growth, lack of growth in soft agar, and a low plating efficiency when seeded at low density. They did not produce tumors when injected in syngeneic animals. Immunochemical studies were performed to determine their origin using antisera prepared against rat small intestinal crypt cell plasma membrane, brush border membrane of villus cells and isolated sucrase-isomaltase complex. Antigenic determinants specific for small intestinal epithelial (crypt and villus) cells were demonstrated on the surface of the epithelioid cells, but they lacked immunological determinants specific for differentiated villus cells. An antiserum specifically staining extracellular material surrounding the cells cultured in vitro demonstrated cross-reactivity to basement membrane in rat intestinal frozen sections. It is concluded that the cultured epithelioid cells have features of undifferentiated small intestinal crypt cells.

Animals↗
PubMed1979

Type IV and type "A-B" collagens do not elicit platelet aggregation or the serotonin release reaction.

Human collagens were isolated from kidney, lung, skin, aorta, cartilage, and placenta. Five different types were obtained, including two new molecular species, one characteristic of basement membranes, or type IV collagen, and the other the recently described "A-B" collagen derived from fetal membranes. All the collagens were purified and separated by combination of heat-gelation fractionation and salt fractionation. In neutral solution at 37 degrees neither type IV nor type "A-B" collagen elicited platelet aggregation or 14C-serotonin release. Preincubation of platelets with both types IV and "A-B" collagen did not inhibit aggregation upon subsequent addition of collagen types I, II, or III.

Aorta↗
PubMed1978

Protective effects of adenosine triphosphate administration in burns.

The effects of intramuscular adenosine triphosphate (ATP) administration after thermal skin injury on the ATP content and morphology of the liver and heart were studied in male Sprague-Dawley rats. The results showed that exogenous ATP injected during the early post-burn period could restore the ATP content of the liver and heart to near normal values and modify the burn-related morphological alterations in the liver.

Adenosine Triphosphatases↗
PubMed1978

Fibrous histiocytoma of the trachea.

The light and electron microscopic features of a fibrous histiocytoma of the trachea that occurred in a 15-year-old Caucasian girl are presented. Emphasis is placed on the aggresive behavior and the importance of early recognition of the lesion in an unusual location.

Adolescent↗
PubMed1978

The use of microscopy as a guide to primary excision of high-tension electrical burns.

High-tension electrical burns sustained by 44 patients were of two types: one is caused by the intense heat of contact with an electric arc, and in the other flow of current against resistance of the deep tissues between arc wounds of entrance and exit produces deep thermal destruction. Microscopic studies in nine patients support the conclusions that such high-tension burns are thermal injuries, that the tissue destruction is not uniform, and that the slow evolution of unexcised wound reflects the admixture of areas of varying tissue viability which may become infected. An aggressive surgical approach designed to minimize tissue loss, avoid infection, and close wounds as early as possible was guided by intraoperative and later microscopic determinations of tissue viability. Despite a high amputation rate in our patients, it was avoided in the upper extremity in three patients, and maximal length of extremities was preserved in seven others. The use of microscopic analysis is recommended to determine the viability of tissues in thermal burns.

Adult↗
PubMed1978

The special state of the fibril end: site of growth, point of cell surface attachment and possible site for platelet interaction.

The end of the collagen fibril is an important and unique morphological site. Growth of fibrils in vitro and in vivo appears to occur by addition of ordered subassemblies of collagen aggregates at the fibril end. In tissues the fibril end appears closely related to the cell surface in both mesenchymal cells and epithelia. In the latter cell type there is an apparent relationship between the basement membrane and fibril end. Platelets do not aggregate upon exposure to basement membranes or collagens derived therefrom. We suggest that the end of the fibril which is embedded in the outer face of the basement membrane may be involved in interaction with the platelet.

Animals↗
PubMed1978

Gastric mucosal lesions after burn injury: relationship to H+ back-diffusion and the microcirculation.

Rats were subjected to a 30% body surface area full-thickness burn. Two hours after injury, 93% of animals had gastric mucosal erosions. At 5 hours this increased to 100%, but at 24 and 72 hours, lesions were fewer and less severe. Histologic study suggested that lesions noted at 24 and 72 hours represented erosions formed earlier. No mucosal abnormalities were noted in control rats. A causal relationship between mucosal ischemia and the development of erosions is suggested by the presence of A-V shunts at 2 and 5 hours only. Significant increases in H+ back-diffusion and protein leakage into the gastric lumen at 2 and 5 hours also implicated changed mucosal permeability in the etiology of erosions. The return of H+ back-diffusion to control values at 24 and 72 hours, when lesions were still present, appears to contradict the theory that permeability changes are secondary to erosion formation.

Animals↗