The contribution of selected anthropometric and physiological variables to 10K performance of wheelchair racers: a preliminary study.

The purpose of this study was to determine the relationship between selected anthropometric and physiological variables and 10K time. Eleven male wheelchair athletes with spinal cord injuries in training for national competition performed continuous progressive exercise tests on a wheelchair ergometer to determine maximal metabolic and cardiorespiratory values. Anthropometric data were also collected. The laboratory data were analyzed for correlation with the best 10K time of each subject during the test period. The subjects averaged 27 min 30 sec for their 10K races, 2.49 L.min-1 for VO2max and 35 percent for maximal gross mechanical efficiency during submaximal exercise. Speed at peak oxygen consumption (r = -0.66), gross mechanical efficiency (r = -0.56), and body density (r = -0.57) was found to be significantly (p less than 0.10) correlated with 10K time. The results show very little correlation between VO2max and 10K time (r = 0.02). Further study is indicated for the relationship between gross mechanical efficiency, speed at maximal oxygen consumption, body density, and 10K time; these variables may be useful in evaluating training programs for improving race performance.     

Use of a new videolaryngoscope (GlideScope®) in the management of a difficult airway

PURPOSE: To describe the clinical use of a new videolaryngoscope in a patient who had repeatedly been difficult or impossible to intubate by conventional direct laryngoscopy. This device provided excellent glottic visualization and permitted easy endotracheal intubation. CLINICAL FEATURES: A 74-yr-old male presenting for repeat elective surgery had a history of failed intubations by direct laryngoscopy and pulmonary aspiration with a laryngeal mask airway. He refused awake flexible fibreoptic intubation. After the induction of general anesthesia, laryngoscopy was performed using a GlideScope. This provided complete glottic exposure and easy endotracheal intubation. CONCLUSION: This new videolaryngoscope provided excellent laryngeal exposure in a patient whom multiple experienced anesthesiologists had repeatedly found to be difficult or impossible to intubate using direct laryngoscopy. The clinical role of this device awaits confirmation in a large series of difficult airways.     

Brief chemotherapy, involved field radiation therapy, and central nervous system prophylaxis for paranasal sinus lymphoma.

Lymphoma of the paranasal sinus is a rare tumor characterized by bulky local disease, early systemic dissemination, and a propensity for central nervous system (CNS) spread. Treatment with radiation alone generally has been disappointing. Based on previous encouraging reports of initial brief chemotherapy followed by involved field radiation therapy (IFRT) for localized large cell lymphoma, four consecutive patients with paranasal sinus lymphoma were treated with 6 weeks of chemotherapy followed by IFRT and CNS prophylaxis. All patients had bulky localized disease and diffuse large cell lymphoma. Complete response was seen in all patients, and none have had a relapse (minimum follow-up, 25 months; range, 25 to 32 months). Chemotherapy and radiation therapy were well tolerated. One patient developed an osteogenic sarcoma in the radiation field 32 months after completion of therapy. Administration of early frequent chemotherapy followed by IFRT and CNS prophylaxis appears to be an effective treatment strategy for patients with localized large cell lymphoma of the paranasal sinuses.     

Reticular cells in peripheral lymphoid tissues express the phosphatidylinositol-linked BP-3 antigen.

The murine BP-3 antigen was initially described as a variably glycosylated cell surface protein of Mr 38,000 to 48,000 on lymphoid and myeloid cells. In the present experiments we found that this antigen is released from the surface of pre-B cells and macrophages by treatment with phosphatidylinositol-specific phospholipase C (PI-PLC), suggesting a glycosyl-phosphatidylinositol (GPI) linkage with the plasma membrane. When the tissue distribution of the BP-3-reactive cells was examined by immunohistology, high levels of the antigen were observed on brush borders of the intestinal epithelial cells, within collecting tubules of the kidney and on a subpopulation of reticular cells located on lymph nodes. Peyer's patches and the white pulp areas of the spleen. In contrast, reticular cells located in the thymus, bone marrow and splenic red pulp did not express the BP-3 antigen. Ontogenic studies revealed that BP-3 was expressed by the reticular cells in peripheral lymphoid tissues in the neonatal period near the time of lymphocyte immigration into these organs. BP-3+ reticular cells were observed in the collapsed periarterial lymphatic sheaths of adult mice depleted of T and B cells by cyclophosphamide treatment and in mice with severe combined immunodeficiency (scid), indicating that development of this reticular network is lymphocyte independent. The BP-3 antigen on the splenic reticular cells was also GPI anchored but its glycosylation pattern differed from that of the BP-3 molecules on pre-B cells. A specific subpopulation of reticular cells is thus marked by the BP-3 antigen, and the distribution and biochemical properties of the molecule make it an attractive candidate for a role in lymphocyte-stromal interactions in the peripheral lymphoid tissues.     

Promutagenic methylation damage in bladder DNA from patients with bladder cancer associated with schistosomiasis and from normal individuals.

Radioimmunoassays (RIAs) have been used to detect the promutagenic lesion O6-methyldeoxyguanosine (O6-MedG) in DNA isolated from the bladder tissues of Egyptian patients presenting with bladder carcinoma and concomitant schistosomiasis (bilharziasis), a parasitic disease known to be associated with the presence of N-nitrosamines in the urine. Alkylation damage was present in the DNA of the majority of the samples (44/46, 96%); 38 samples were of tumour tissue and 8 from uninvolved bladder mucosa. Levels of O6-MedG ranged from undetectable (ND; i.e. less than 0.01 mumol O6-MedG/mol dG) to 0.485 mumol/mol dG with an overall mean of 0.134 +/- 0.10 mumol/mol dG, including the two samples that were below the limit of detection. In contrast, methylation damage was detected in only 4/12 (33%) of the DNA samples from normal bladder tissue of European origin. In these samples levels of O6-MedG ranged from ND to 0.225 mumol/mol dG with an overall mean of 0.046 +/- 0.082 mumol O6-MedG/mol dG. These results confirm that alkylation events can be detected in the DNA of schistosome-infected human bladder tissue. The methylation of uninvolved and tumour tissue DNA to similar extents suggests that the alkylating intermediate may have been present in the urine. These results indicate the need for further investigation to determine whether relationships exist between levels of DNA damage and the prevalence of schistosome infection and/or the extent and type of bacterial infection that frequently accompanies this disease.     

Mutated recombinant human heavy-chain ferritins and myelosuppression in vitro and in vivo: a link between ferritin ferroxidase activity and biological function.

Human heavy-chain (H-) ferritin muteins obtained by oligonucleotide site-directed mutagenesis, together with wild-type recombinant human H- and light-chain (L-) ferritins, were evaluated for in vitro effects on the suppression of human bone marrow myeloid progenitor cells and for in vivo effects on marrow and splenic myelopoiesis in C3H/HeJ mice. The 10 H-ferritin muteins exhibited alterations of various regions of the molecule, including ones exposed on the outer surface, on the inner cavity, and on the hydrophilic and hydrophobic channels and of the four-alpha-helix bundle forming the subunit structure. They were stable and were electrophoretically analogous to wild-type H-ferritin. The muteins showed in vitro and in vivo myelosuppressive activity analogous to wild type, except for mutein 222, which was totally inactive and which lacked ferroxidase activity. Recombinant human L-ferritin, devoid of ferroxidase activity, was also inactive as a suppressor. The results demonstrate that H-ferritin myelosuppressive and ferroxidase activities are linked. One possibility is that ferroxidase activity may interfere with the cellular uptake of transferrin iron that is needed for cell proliferation, an interpretation consistent with the presently described ability of hemin to overcome H-ferritin suppressive effects.     

Influence of murine mast cell growth factor (c-kit ligand) on colony formation by mouse marrow hematopoietic progenitor cells.

Purified natural and recombinant murine mast cell growth factor (MGF, a c-kit ligand) were evaluated alone and in combination with other cytokines for effects in vitro on colony formation by multipotential (CFU-GEMM), erythroid (BFU-E) and granulocyte-macrophage (CFU-GM) progenitor cells from BDF1 mouse bone marrow. Both preparations stimulated Epo-dependent CFU-GEMM and enhanced Epo-dependent BFU-E colony numbers and size. MGF had some stimulating activity for CFU-GM. When used in combination with plateau concentrations of pokeweed mitogen mouse spleen cell conditioned medium or granulocyte-macrophage colony stimulating factor (CSF), MGF enhanced in greater than additive fashion colony formation by CFU-GM. MGF also enhanced the size of colonies formed, an enhancement greatest for colonies containing granulocytes and macrophages. MGF did not enhance Macrophage-CSF stimulated colony numbers or size. MGF seems to be an early acting cytokine with preferential effects on the growth of more immature hematopoietic progenitor cells.     

A retrospective analysis of the efficacy and safety of metformin in the African-American patient.

A retrospective analysis was conducted to determine the effects of metformin on glycosylated hemoglobin (HbA1c), body weight, and adverse events in an African-American population. Thirty-six patients who were receiving combination therapy with metformin and either a sulfonylurea or insulin were identified from a hospital pharmacy database. Nineteen patients met the criteria for efficacy analysis. The combination of metformin with either a sulfonylurea or insulin resulted in a decrease of the average HbA1c from a baseline of 10.07% to 7.92% (delta = 2.15%). The effect of combination therapy on weight was variable; however, twice as many patients lost weight compared with those who gained weight. Metformin appeared to be well-tolerated, with gastrointestinal symptoms being the most commonly reported adverse events.