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Biomedical subjects

C Lowe

Publications and source records attributed to C Lowe.

66 records · Page 4Linked to original sources
PubMed1980

Effect of purification steps on the immunogenicity of Mycobacterium leprae.

In studies aimed at the development of an antileprosy vaccine for use in man, Mycobacterium leprae suspensions were prepared from livers of experimentally infected armadillos. The 2 methods of purification in chief use, carried out after irradiation of the tissue with 2.5 megarads of gamma irradiation from 60Co, involved treatment with 0.1N NaOH for 2 h at room temperature, trypsin and chymotrypsin digestion for 24h at 37 degrees, and separation in a 2-phase liquid polymer (dextran:polyethylene glycol) system. All vaccines were autoclaved and injected intradermally in mice. Earlier studies have shown that heat inactivation does not interfere with the immunogenicity of M. leprae. Immunogenicity was measured by foot-pad enlargement (FPE) after challenge with heat-killed M. leprae suspensions or by protection against infectious foot-pad challenge. The results indicated that the irradiation and 2-phase separation did not decrease immunogenicity but the NaOH treatment and enzyme digestion did.

Animals↗
PubMed1979

Plasmapheresis and lymphoplasmapheresis in the management of rheumatoid arthritis.

We have demonstrated the efficacy of therapeutic pheresis in a number of rheumatic diseases, especially rheumatoid arthritis (RA). Ten of 12 patients with RA went into remissions averaging 4 months. These patients were pheresed 20 times over 11 weeks in a tapering fashion on a Haemonetics Model 30 Blood Processor. Clinical remissions were sustained even though serologies, immunoglobulins, immune functions, sedimentation rates, and circulating immune complexes returned to their pre-pheresis baseline by pheresis number 20. All these patients were taking gold or D-penicillamine concurrently, but neither of the 2 patients who failed to respond was on these agents. Plasmapheresis was just as effective as lymphoplasmapheresis. It is theorized that removal of a plasma factor that modulates lymphocyte or neutrophil function produces remissions in RA and that long-acting drugs (e.g., gold or penicillamine) are able to prevent its continued production and produce a sustained remission.

Adult↗
PubMed1979

Liquid ventilation: cardiovascular adjustments with secondary hyperlactatemia and acidosis.

Cardiovascular adjustments during liquid ventilation were investigated in seven cats. Cardiac output (CO) and regional blood flow were measured with radioactive microspheres during both spontaneous air breathing (control) and ventilation with fluorocarbon liquid, FC-80. CO was found to decrease 48% (P less than 0.05) during liquid breathing as compared to control. This decrease largely reflected a reduced stroke volume. Despite the decreased CO, mean arterial pressure remained unchanged, indicating a 48% increase (P less than 0.002) in total peripheral resistance (TPR). Secondary to the reduced CO and increased TPR, extensive redistribution of blood flow occurred during liquid ventilation. The arterial lactate concentration and lactate-to-pyruvate ratio (L/P) were significantly increased (P less than 0.02). Furthermore, the increase in L/P correlated with the decrease in CO (r = 0.70; P less than 0.01). In turn, the significant decrease in pH during liquid breathing was found to correlate with the increase in L/P (r = 0.85; P less than 0.001). These data clearly demonstrate signficant alterations in cardiovascular dynamics during liquid ventilation with secondary hyperlactatemia and acidosis.

Animals↗
PubMedDate not supplied

Long-term plateletpheresis in the management of primary thrombocytosis.

We attempted to control the platelet count of a patient with primary thrombocytosis utilizing long-term plateletpheresis therapy. The patient previously could not be controlled with chemotherapy, because of rapid development of leukopenia. Although intensive pheresis at the rate of four to five procedures per week produced rapid lowering of the patient's platelet count, continued therapy at the rate of two to three procedures a week failed to maintain these counts, and platelets gradually rose to pretreatment levels. We conclude that while plateletpheresis can produce acute lowering of elevated platelet counts, the rate of platelet production in primary thrombocytosis may be too rapid to allow for long-term control by pheresis alone, utilizing an acceptable treatment schedule of one of three procedures per week.

Blood Transfusion↗
PubMedDate not supplied

Use of long-term leukapheresis in the treatment of chronic lymphocytic leukemia.

We used repeated leukapheresis in the long-term management of chronic lymphocytic leukemia. Twelve patients with far-advanced disease that was refractory to standard forms of therapy, were studied. Six patients completed a predefined course of therapy. Although a single patient responded favorably for a period of time, no other patient was benefited by this treatment. While circulating lymphocyte counts in these patients always could be reduced, generally, this was not associated with improvements in pancytopenia, hypogammagobulinemia, adenopathy, organomegaly, or constitutional symptoms of lethargy, fevers and night sweats. Mean survival was only ten months from onset of therapy. We conclude that long-term leukapheresis is ineffective in the management of far-advanced chronic lymphocytic leukemia.

Agammaglobulinemia↗
PubMedDate not supplied

Prevention of adverse reactions to blood transfusion by the administration of saline-washed red blood cells.

We prospectively compared the incidence of complications following saline-washed versus packed red blood cell transfusions, to determine whether routine use of washed red blood cells could reduce significantly the incidence of transfusion reactions. Clinical reports of reactions were evaluated carefully to confirm whether the reaction was caused by transfusion. In 3,799 washed red blood cell transfusions, there were eight confirmed reactions (0.21%). Of 6,359 packed red blood cell transfusions, 31 reactions occurred (0.49%). The difference in incidence of confirmed complications was statistically significant (p less than 0.03). Administration of washed red blood cells to all patients requiring transfusions can thus be seen to reduce significantly the incidence of adverse reactions. This is likely the result of the removal of leukocytes and plasma achieved by the washing process. The increased safety of washed red blood cells must be weighed against their extra expense to determine their cost-effectiveness in transfusion therapy.

Blood Preservation↗
PubMedDate not supplied

Repair of five distal radius fractures with an investigational cancellous bone cement: a preliminary report.

OBJECTIVE: The purpose of the study was to evaluate the feasibility of Norian SRS bone cement injected percutaneously into a distal radius following reduction in both preventing loss of reduction as well as safety. DESIGN: The study was a prospective clinical study with an established protocol. SETTING: The study was conducted at the Massachusetts General Hospital following approval of the institutions Investigational Review Board. All patients were required to read and approve an informed consent document. PATIENTS: While twenty patients' radiographs fulfilled the requirement of a dorsally displaced extraarticular fracture to have occurred within 72 hours of presentation, only five consented to participate fully and one voluntarily withdrew after a six-month follow-up. INTERVENTION: All fractures were reduced under regional or general anesthesia, and the Norian SRS was introduced via a catheter system into the metaphyseal defect of the fracture. A short arm cast was applied and remained in place for six weeks. MAIN OUTCOME MEASUREMENTS: Radiographic parameters of fracture reduction were measured prospectively by an independent radiologist throughout the 12 months of the study. Clinical parameters of hand and wrist function were measured prospectively by an independent occupational therapist. RESULTS: At 12-month follow-up, radial length was a mean 9.9 mm with an average loss of < 1 mm; radial angle maintained at a mean 25.4 degrees; volar angle was within normal range (0-21 degrees) in 4; and 1 patient had a dorsal angle of 7 degrees. Wrist motion improved 50 percent between 6 weeks and 3 months and improved further by 12 months when grip strength reached a mean of 88 percent of the contralateral side. Dorsal and volar extrusion of injected Norian SRS in 4 patients resorbed over time. There were no clinically significant adverse effects or complications. CONCLUSIONS: Norian SRS proved to be clinically safe and effective as a cancellous bone cement to maintain fracture reduction of unstable extraarticular distal radius fractures.

Bone Cements↗
PubMedDate not supplied

Health in Action.

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Alberta↗
PubMedDate not supplied

A study of alleged leprosy bacillus strain HI-75.

Subcultures of strain HI-75 of Skinsnes leprosy bacillus received in Antwerp and London have been studied bacteriologically and compared. Both contained moderately large acid-fast bacilli readily subcultured and maintained on ordinary mycobacteriologic media. These organisms were found to be a variety of Mycobacterium marianum (syn. serofulaceum) and were considered likely to be a laboratory contaminant. The earlier subculture studied also contained numbers of a much smaller mycobacterium (of a similar size to M. leprae) which appeared to be dead and which did not grow on the ordinary media. Skin tests and immunodiffusion analyses performed with extracts of the earlier subculture failed to demonstrate the presence of the specific antigens of leprosy bacilli. Similar studies on other cultures of Skinsnes bacillus must be performed to confirm or refute its identity as M. leprae.

Cell Wall↗