Automated venous occlusion plethysmograph.
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Humans↗
Biomedical subjects
F M Davis
Publications and source records attributed to F M Davis.
Immunological evidence for the relation between low MR secreted form of human B cell growth factor and an intracellular 60K protein.
Homogeneously purified intracellular high-Mr BCGF (IC-BCGF) has been used as an immunogen for the development of heterotypic anti-IC-BCGF antibodies. Anti-IC-BCGF immunoglobulin has been purified by affinity chromatography and used for constructing an immunoaffinity matrix. This matrix was shown to recognize specifically IC-BCGF and the extracellular low-Mr secreted form of human BCGF (EC-BCGF). In the cytosolic extracts of lectin activated human PBLs two other proteins of 50K and 30K were also recognized by these antibodies. Immuno dot blot and western blot analysis also demonstrated that anti-IC-BCGF antibodies recognized EC-BCGF. These antibodies weakly interacted with human interferons (alpha, gamma). Immunoaffinity-purified IC-BCGF was shown to have a molecular weight of 60K, and it exhibited BCGF activity in long-term BCGF-dependent B cell lines. The Mr of one-step affinity-purified EC-BCGF was found to be 14K by SDS-PAGE analysis. This material demonstrated BCGF activity in both long-term BCGF-dependent B cell lines and anti-IgM-activated GoB cells, yet it did not exhibit IL-1 and IL-2 activities. We conclude that EC-BCGF is immunologically related to IC-BCGF through common structural epitopes.
Antibody Specificity↗
Effects of transcutaneous scopolamine and depth on diver performance.
Transdermal scopolamine is an effective anti-motion-sickness medication that has less CNS side effects at normal ambient pressure than orally ingested agents. To see whether it has an effect on performance at depth, 24 healthy sport divers were exposed to depths equivalent to 5 m (1.5 ATA) and 36 m (4.8 ATA) in a dry recompression chamber, breathing air and wearing a skin patch containing either scopolamine or inactive placebo. Patches and dive depths were presented in a counterbalanced, double-blind experimental design. Tests of sentence comprehension, simple arithmetic, and manual dexterity were used to evaluate psychometric and cognitive performance. Drug side effects were recorded. The Bennett Hand Tool Dexterity Test was evaluated for its suitability for repeated measures testing, and found to be robust. Manual dexterity and sentence comprehension were significantly impaired at depth whereas arithmetic skills were not. No significant effects on diver performance from transdermal scopolamine were seen. Certain side effects such as blurred vision were more common with scopolamine than with placebo. The use of transdermal scopolamine as an antiemetic during diving operations deserves field evaluation.
Administration, Cutaneous↗
Protein phosphorylation and dynamics of cytoskeletal structures associated with basal bodies in Paramecium.
The presence of phosphorylated proteins associated with microtubule organizing centers in tissue culture cells during mitosis has been demonstrated by the use of monoclonal antibodies raised against mitotic HeLa cells [Vandre et al., Proc. Natl. Acad. Sci. U.S.A. 81:4439-4443, 1984]. We report here that in Paramecium two of the mitosis specific antibodies, MPM-1 and MPM-2, decorate throughout the cell cycle all the microtubule organizing centers (MTOCs) located in the cortex and in the oral apparatus (gullet). Immuno-electron microscopy showed that these antibodies labeled the electron-dense material surrounding basal bodies from which several microtubule networks as well as kinetodesmal fibers originate. During mitosis, these antibodies also stained other cortical cytoskeletal structures, the kinetodesmal fibers (MPM-1 and MPM-2) and the epiplasm (MPM-1). Among the different polypeptides recognized by the antibodies on immunoblots, three major ones of 60, 63, and 116 kDa were found to be common to the cortex (where several thousand ciliary basal bodies are anchored) and the oral apparatus (which comprises several hundred basal bodies around which various arrays of cytoplasmic microtubules are organized). Alkaline phosphatase treatment abolished the immunoreactivity of the polypeptides and the labeling observed by immunofluorescence. These results demonstrate that phosphorylated proteins are associated with all the known active microtubule organizing centers present in the cortex throughout the cell cycle of Paramecium. Furthermore they indicate that in Paramecium phosphorylation of proteins could also be involved in the cell cycle dependent dynamics of cortical cytoskeletal structures other than microtubules.
Animals↗
Monoclonal antibody with specificity to mitotic chromosomes of primates.
Fusion of a cell in mitosis with a cell in interphase results in the condensation of chromatin in the interphase nucleus into chromosomes. Premature chromosome condensation is caused by certain proteins, called mitotic factors, that are present in the mitotic cell and are localized on chromosomes. Extracts from mitotic cells were used to immunize mice to produce monoclonal antibodies specific for cells in mitosis. Among the antibodies obtained, the MPM-4 antibody defines a 125-kD polypeptide antigen located on mitotic chromosomes by indirect immunofluorescence. Although the polypeptide antigen is present in approximately equal concentrations in extracts of interphase cells and mitotic cells, as revealed by immunoblots, it cannot be detected cytologically in the former. Cell fractionation experiments showed that the 125-kD antigen is found in the cytoplasm of interphase cells and metaphase cells, but is concentrated in fractions containing metaphase chromosomes, although not detectable in interphase nuclei. Even though the antigen is apparently primate-specific, it binds to mitotic chromosomes and prematurely condensed chromosomes in human-rodent cell hybrids without regard to the species of origin of the mitotic inducer. The presence of the antigen in the cytoplasm of interphase cells and the chromosomes of mitotic cells suggests a relationship between the presence of the antigen on chromosomes and the process of chromosome condensation and decondensation.
Animals↗
Influence of spinal and general anaesthesia on haemostasis during total hip arthroplasty.
One hundred and one patients with osteoarthritis were randomly allocated to undergo total hip arthroplasty under either spinal (subarachnoid) or general anaesthesia. Venous blood was sampled before, during and after surgery and on the 5th day after operation to study the haemostatic mechanism. There were no preoperative differences between the two anaesthetic groups. Although there was pronounced individual variability, similar patterns of change in coagulation, platelets and fibrinolysis were seen in both groups. However, there were significant differences between the two groups in platelet count, thrombin production, and Factor VIIIRAg in the intra- and immediate postoperative periods. Also, compared with general anaesthesia, there was less intraoperative activation of fibrinolysis, as measured by the euglobulin clot lysis time, with spinal anaesthesia. These differences suggest slight modification of the haemostatic response to surgery with spinal anaesthesia, which could be consistent with a neuroendocrine mechanism. By the 5th day both groups exhibited a very similar "hypercoagulable" postoperative state.
Aged↗
Metabolic response to total hip arthroplasty under hypobaric subarachnoid or general anaesthesia.
Whole blood glucose concentration was estimated in 93 patients undergoing total hip arthroplasty under either subarachnoid or general anaesthesia. In 77, plasma cortisol concentration was also estimated before and after surgery. There were no preoperative differences between the two groups. Blood glucose concentration increased slightly following induction in both groups, but with spinal anaesthesia it decreased again, whereas with general anaesthesia it continued to increase (P less than 0.0001). Plasma cortisol concentration with spinal anaesthesia was 291 (SD 145) nmol litre-1 before, and 279 (253) nmol litre-1 30 min after operation. With general anaesthesia there was a three-fold increase from 301 (159) nmol litre-1 (preoperative) to 987 (474) nmol litre-1 30 min after operation (P less than 0.0001). Low spinal anaesthesia with a predominantly unilateral block appears sufficient to suppress the neuroendocrine response to hip surgery.
Aged↗
Prospective, multi-centre trial of mortality following general or spinal anaesthesia for hip fracture surgery in the elderly.
In a prospective randomized multi-centre study, the mortality following internal fixation surgery for fracture of the upper femur was investigated in 538 elderly patients allocated to receive subarachnoid blockade or general (narcotic-relaxant) anaesthesia. The 28-day mortality was 6.6% with subarachnoid, and 5.9% with general, anaesthesia. The difference was not significant (95% confidence limits: -3.5 to +4.8). At 1 year following surgery, the mortality was 20.4%. Increasing age, ischaemic heart disease, cardiac failure, preoperative arrhythmias and poor ASA status were all associated with increases in early and long term mortality. A delay to surgery of more than 24 h from admission was also associated with an increased 28-day mortality. Senile dementia and admission other than from the patient's own home, were factors associated with a poorer long term outcome. From the point of view of mortality, subarachnoid anaesthesia did not appear to confer any advantages over general anaesthesia in non-prosthetic surgery for hip fracture in the elderly.
Aged↗
Conditional absence of mitosis-specific antigens in a temperature-sensitive embryonic-arrest mutant of Caenorhabditis elegans.
A monoclonal antibody, specific to phosphoproteins in mitotic HeLa cells was found to crossreact with a similar set of proteins in embryos of the nematode, Caenorhabditis elegans. In C. elegans, as in mammalian cells, the highly conserved antigenic epitope is associated with a family of high molecular weight polypeptides. The antigenic reactivity of these multiple proteins also depends on their phosphorylation, since antibody binding is reduced after alkaline phosphatase treatment. The antigens are detected at the centrosomes, and in the nuclear region and surrounding cytoplasm of mitotic cells. The significance of these antigens is emphasized by their absence at restrictive temperature in embryos of the temperature-sensitive embryonic-arrest mutant, emb-29V. Furthermore, temperature shift-down experiments suggest that the emb-29 mutation defines a cell division cycle function that affects an essential activity required for progression into M phase.
Animals↗
Carbon dioxide response and breath-hold times in underwater hockey players.
Competitive underwater hockey play demands frequent and prolonged breath-hold dives. To see whether participants were physiologically adapted to breath-hold diving we studied the ventilatory response to carbon dioxide (CO2) and the breath-hold times of 34 male, underwater hockey players (divers) and compared them to 28 male, dry-land sportsmen (athletes). The divers showed an increased tolerance to CO2, the mean (+/- SD) slope of the CO2 response curve being 1.08 (+/- 0.55) liter.min-1.mmHg CO2(-1) when measured by the rebreathing method. This was significantly less (P less than 0.005) then that of the athletes 1.68 (+/- 0.72) liter.min-1.mmHg CO2(-1). The breath-hold times measured at 2 lung volumes did not differ significantly between the 2 groups. A subgroup of 8 international underwater hockey players exhibited prolonged breath-hold times but were otherwise similar to the rest of the divers in the other measured parameters.
Adult↗
Hyperbaric oxygen therapy in the management of Clostridium perfringens infections.
Patients with Clostridium perfringens infections treated in Christchurch over a 14 year period to 1984 were reviewed retrospectively. Of the 46 documented cases, 21 died. Twenty-nine patients were treated with hyperbaric oxygen (HBO) therapy. Of these, nine died, whilst 12 of 17 other patients who did not receive HBO died, including five in whom the diagnosis was only made at postmortem. The clinical features and predisposing factors for clostridial infections are discussed. The importance of early vigorous treatment with a combination of surgical debridement, antibiotics and HBO to reduce the morbidity and mortality of this lethal infection is emphasised.
Adult↗
Management of severe ARDS with low frequency positive pressure ventilation and extracorporeal CO2 removal.
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Adult↗
Double immunoenzymatic labeling of lymphomatous tissues for both immunologic phenotype and a malignancy-associated nucleolar antigen.
Defining cell lineage in the non-Hodgkin's lymphomas (NHL) is challenging for the immunopathologist. Cell surface marker techniques have made a major contribution to the understanding of the biology and classification of lymphoproliferative disorders by permitting the determination of the lymphoid (B- or T-cell) or monocytic lineage of the tumors. Because lymphoma cells often simulate the morphologic features and cell surface phenotype of their normal lymphocytic counterparts, it is difficult to discriminate normal from neoplastic lymphocytes. The authors have used representative monoclonal antibodies (MAb) to cell surface antigens to assess tumor cell surface antigens associated with various lymphoreticular cell lineages. Heteroantisera to the human malignancy-associated nucleolar antigen (HMNA) was utilized as a marker for neoplastic lymphoid cells as previously described. The use of double immunoenzymatic staining with both peroxidase and alkaline phosphatase allow us simultaneously to determine lymphoid lineage and malignancy on human lymphoma cells. In 101 cases of various cell types of NHL, the anti-HMNA antiserum reacted with nucleoli in the morphologically neoplastic lymphoma cells, but not with normal-appearing lymphoid and other cell types present in the lesions. Control specimens from normal and hyperplastic lymphoid tissue also failed to react with anti-HMNA antibodies.
Antibodies, Monoclonal↗
Distribution of cytoskeletal proteins sharing a conserved phosphorylated epitope.
A group of antigens related by their reactivity with monoclonal antibodies MPM-1 and MPM-2 appear as cells enter mitosis. These antibodies bind to a phosphorylated epitope on certain proteins, and therefore the antigens are presumed to be a group of phosphoproteins. A subset of these proteins has been shown previously to be components of mitotic microtubule organizing centers in PtK1 cells. We present here evidence that the mitosis-specific appearance of these phosphoproteins is a phenomenon common to all eukaryotic cells. The MPM reactive phosphoproteins were localized to mitotic spindle poles regardless of whether the spindle formed in the cytoplasm after nuclear envelope breakdown (open mitosis) or within the nucleus (closed mitosis). This reactivity was not dependent upon the presence of centrioles at the spindle poles. Proteins that contained the phosphorylated epitope were not, however, restricted to mitotic cells. Cells of neuronal derivation and flagellated cells showed specific localization of MPM antibody to the microtubule network and basal bodies respectively. On immunoblots, the MPM antibody reacted with brain MAP-1 among a number of other phosphoproteins. The identification of microtubule-associated protein (MAP)-1 correlates with the localization of the antibody to microtubules of neuroblastoma cells. These results suggest, that different phosphoprotein molecules detected by the MPM antibody may be specific for different mitotic microtubule organizing centers, basal bodies, and other specialized cytoskeletal structures; and the presence of a related phosphorylated domain on these proteins may be important for their proper function and/or interaction with microtubules.
Animals↗
Partial purification and characterization of mitotic factors from HeLa cells.
Extracts from mitotic HeLa cells, when injected into Xenopus laevis oocytes, exhibit maturation-promoting activity (MPA) as evidenced by the breakdown of the germinal vesicle and the condensation of chromosomes. In this study we have attempted to purify and characterize these mitotic factors. When 0.2 M NaCl-soluble extracts of mitotic HeLa cells were concentrated by ultrafiltration and subjected to affinity chromatography on hydroxylapatite followed by DNA-cellulose, the proteins with MPA eluted as a single peak and their specific activity was increased approx. 200-fold compared with crude extracts. The molecular weight of the mitotic factors was estimated to be 100 kD as determined by chromatography on Sephacryl S-200. SDS-PAGE of the partially-purified mitotic factors indicated the presence of several polypeptides ranging from 40-150 kD with a major band of about 50 kD. The majority of these polypeptides were found to be phosphoproteins as revealed by 32P-labeling and autoradiography. Very little or no phosphorylation was observed at the 50 kD band. Several of these polypeptides were reactive with mitosis-specific monoclonal antibodies, MPM-1 or MPM-2, as shown by immunoblots of these proteins but the major polypeptide band at 50 kD was not. Removal of the immunoreactive polypeptides by precipitation with these antibodies did not destroy the MPA. The MPA of the crude or the partially-purified mitotic factors was destroyed by injection of (but not pretreatment with) alkaline phosphatase within 45 min after injection of mitotic factors. These results are discussed in terms of a possible role of phosphorylation-dephosphorylation of non-histone proteins in the regulation of mitosis and meiosis.
Alkaline Phosphatase↗
Negative pressure drainage after craniotomy.
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Adult↗
Lower limb blood flow during transurethral resection of the prostate under spinal or general anaesthesia.
Using venous occlusion impedance plethysmography, leg blood flow was measured in seventeen men undergoing transurethral prostatectomy under either amethocaine spinal anaesthesia (SAB) or nitrous oxide-halothane general anaesthesia (GA). Mean leg blood flow doubled (206% of pre-operative control value) following induction of SAB, remained elevated throughout surgery (146% of control at the end of operation) and had returned to pre-operative levels (94%) by two hours postoperatively. Under GA, mean blood flow rose gradually during surgery to 136% of control by the end. However, mean blood flow was only 28% of control at one hour postoperatively, rising to 66% of control by two hours. Analysis of variance showed a significant difference in blood flow changes between the two groups (Greenhouse Geisser P = 0.005). The early postoperative fall in leg blood flow in the GA group might be important in the aetiology of postoperative deep vein thrombosis.
Anesthesia, General↗
An adverse reaction to chlormethiazole.
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Aged↗