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Biomedical subjects

C L Olson

Publications and source records attributed to C L Olson.

At least 37 records · Page 2Linked to original sources
PubMed1987

Naloxone in renal ischemia: a functional and microanatomical study.

Naloxone HCl (Nx) improves cardiopulmonary performance, reverses cellular hypoxia, and stabilizes lysosomal membranes in shock states. However, no detailed study has yet explored its potential role in renal ischemia, which is inevitable in transplantation and surgical and nonsurgical conditions associated with hypotension and shock. This functional and microanatomical study was carried out on dogs subjected to renal warm ischemia with contralateral nephrectomy. Group I (control; N = 4) had bilateral renal dissection and right nephrectomy. Groups II-IV had their kidney pedicles cross-clamped for 60 min and then reperfused. Group II (N = 9) ischemic kidneys received no treatment. Group III (N = 6) kidneys were flushed with pure Nx HCl (2 mg/kg) during ischemia. Group IV (N = 6) dogs received one iv Nx bolus (2 mg/kg) before clamping and another dose before declamping. Biopsies for adenine nucleotides, histology, and ultrastructure were obtained before ischemia, before reflow, and 15 min and 7 days after reflow. Serum creatinine and blood urea nitrogen were measured daily. Ischemia induced significant renal dysfunction, which was reversed by systemic Nx. Nx offered a remarkable protection against postischemic structural damage. Seventy percent of Group II cortical sections showed grade 4 acute tubular necrosis (ATN), and severe residual damage after a week. Eighty-three percent of Group IV sections showed grade 1 ATN and no residual damage after a week. One week survival was 33% in Group II and 100% in Group IV. Nx can be useful in prevention of acute renal failure in clinical situations with arterial hypotension and shock.

Acute Kidney Injury↗
PubMed1985

Activation of rat B lymphocytes by Actinobacillus actinomycetemcomitans.

We examined the lymphoproliferative responses of cervical lymphocytes and splenocytes of homozygous (rnu/rnu) congenitally athymic nude and normal heterozygous (rnu/+) Rowett rats to whole cells of Actinobacillus actinomycetemcomitans, a suspected periodontal disease pathogen. Previously sensitized cells from immunized only, infected only, or immunized and infected, normal rats demonstrated proliferation in response to formalinized A. actinomycetemcomitans, but cells from nude rats did not proliferate. The maximum antigenic response was observed at day 5 of culture. A. actinomycetemcomitans caused cervical lymphocytes and splenocytes from untreated naive normal and nude rats to undergo increased DNA synthesis at day 2 of culture. Highly enriched nonsensitized spleen T cells prepared on a nylon wool column did not respond to A. actinomycetemcomitans, whereas enriched nonsensitized B cells proliferated. Differences in response were probably not attributable to contributions from macrophages in the T- or B-cell populations, since macrophage percentages were approximately the same in both preparations. T-cell reconstitution of nude rats with neonatal thymus cells from rnu/+rats resulted in partial recovery of T-cell function but had no effect on the mitogenic response to A. actinomycetemcomitans. It is suggested that the antigenic responses to A. actinomycetemcomitans are dependent on T cells and that A. actinomycetemcomitans cells have mitogenic activity for B cells. The potential importance of these findings in periodontal disease is discussed.

Actinobacillus↗
PubMed1985

Periodontal bone loss and immune characteristics of congenitally athymic and thymus cell-reconstituted athymic rats.

We investigated the ability to reconstitute the T-cell deficiency in congenitally athymic (nude; rnu/rnu) Rowett rats by intravenous injection of 10(7) heterozygous normal (rnu/+) rat thymus cells. The thymus cell-reconstituted animals showed essentially normal lymphocyte proliferation to phytohemagglutinin P and concanavalin A, normal spleen and lymph node T-lymphocyte distribution, and normal serum immunoglobulin G levels. These rats were used to study the effect of T-cell deficiency on periodontal disease. Animals with minimal oral flora were divided into three groups: nude, thymus cell-reconstituted nude, and normal rats. Immune response, gingival inflammation, and periodontal bone loss were examined in these animals. Less than 40% of the T cells recovered from the normal rat gingiva could be recovered from the nude rat gingiva. In contrast to the situation in normal or thymus cell-reconstituted rat gingiva, B cells were vastly predominant in the nude rat gingiva, with approximately four B cells for each T cell. There was increased periodontal bone loss in the nude rats compared with that in the normal rats. Thymus cell reconstitution of the nude rats was associated with decreased bone destruction. It is suggested that T cells have a regulatory function in relation to the potentially excessive B-cell response to abundant antigen and polyclonal activators in the oral cavity.

Animals↗
PubMed1984

Host response in experimental periodontal disease.

Experiments were performed to determine the role of the immune response in rat periodontal disease. Germ-free rats were fed defined antigen-free liquid diets or a diet containing ovalbumin(OVA) as a prototype antigen. The OVA-fed rats demonstrated increased gingival lymphocytes (mainly T at early times), OVA-sensitized spleen cells, and increased periodontal bone loss. In further studies, rats pre-sensitized with OVA, and receiving OVA in the diet, showed elevated IgG antibody, sensitized spleen cells, and elevated periodontal bone loss scores. The concept that bone loss was due to mixed hypersensitivity reaction is consistent with the periodontal pathology. The effects of pre-immunization with A. actinomycetemcomitans (Aa) on periodontal bone loss in Actinobacillus (Aa) - infected rats was examined. Delayed hypersensitivity (DTH) was present in immunized rats throughout the experimental period. Sham-immunized rats showed DTH after 30 days of infection. In addition, immunized rats showed elevated bone loss scores. These experiments support the contention that a combination of hypersensitivity reactions (i.e., mixed hypersensitivity to Aa) could give rise to the periodontal pathology observed. Congenitally athymic rats (nude) were shown to have more periodontal bone loss than did normal littermates. However, bone loss in thymus-cell reconstituted nude rats was not different from that in control rats. Normal rats receiving Aa-sensitized T lymphocytes prior to infection with Aa demonstrated increased DTH and periodontal bone loss. These studies support the concept that T-cell functions and thymic regulation of immune responses can exert protective and/or destructive effects in periodontal disease. In order to modify disease, it will be necessary to enhance the protective aspects of the immune response and to minimize the detrimental aspects.

Actinobacillus↗
PubMed1982

Development of a multichannel electrochemical centrifugal analyzer.

A new instrument has been developed that is similar in design and concept to the GeMSAEC centrifugal analyzer (Oak Ridge National Laboratory) except that electrochemical detection is used rather than optical detection. The present version has eight channels, each with its own detector. Problems of speed control and sampling synchronization are greatly minimized from those of a multichannel centrifugal analyzer having a single detector system. All eight sample compartments and polarographic cells are contained in a single Teflon rotor, 7.7 cm in diameter. The working electrodes are planar carbon electrodes. The initial application of the analyzer is in kinetic methods involving the rates of enzyme-catalyzed reactions. The initial system chosen was the glucose oxidase system. When the rotor is spun, the solution moves into the sample cell and up against the planar working electrode. The reaction starts and current is measured as a function of time at a constant applied voltage. The current output from each polarographic circuit is connected to a separate channel of a multiplexed analog-to-digital converter. The analyzer is controlled by a dedicated microcomputer system, which sets the polarographic cell voltages, collects the current-time data, and calculates the results.

Autoanalysis↗
PubMed1976

Sarcoidosis with optic nerve and retinal involvement.

A patient with the typical funduscopic changes of sarcoidosis died following an accident. The histopathological findings in one eye were correlated with the ophthalmoscopic observations made several days prior to death. Gross and histopathological examination revealed that the characteristic whitish-yellow focal retinal exudates, the perivascular exudates with an appearance like candle wax drippings, the preretinal and intravitreal nodules, and the localized tumefactions on the inner surface of the retina and optic nerve head noted ophthalmoscopically were a result of the nodular proliferation of epithelioid cells. These cells appeared to be derived primarily from blood vessels in the retina and optic nerve head. Although subpigment epithelial granulomas were found, there were no granulomas present within the choroid or elsewhere within the uvea.

Adult↗