Physical aspects of total-body irradiation at the Middlesex Hospital (UCL group of hospitals), London 1988-1993: II. In vivo planning and dosimetry

Part II of this paper gives the results of applying the TBI methods described in part I, to in vivo patient planning and dosimetry. Patients are planned on nine CT based body slices, five of which pass through the lungs. Planned doses are verified with ten silicon diodes applied bi-laterally to five body sites, at each treatment. LiF TLDs are applied to seven other body sites at the first treatment only. For 84 patients and at least 1016 measurements per body site with the diodes, the mean measured total doses agreed with planned doses within at most 2% except at lung levels, where the mean measured dose was 3% too low. Standard deviations of the measurements about the mean were between 2.4 and 3.1%. For the LiF TLDs, the mean measured doses for all seven body sites were with in +/- 5% of planned doses. A separate assessment of measured entrance and transmitted doses showed that the former agreed well with planned doses, but that the latter tended to be low, especially over the lungs, and that they had a wider dispersion. Possible reasons for this are discussed. These results show measurement uncertainties similar to those for non-TBI treatments of Nilsson et al, Leunens et al and Essers et al. An analysis of the treatment plans showed a mean dose inhomogeneity in the body (75 patients, nine slices) of 19 +/- 6.0% (1 s.d.) and in the lungs (40 patients, five slices) of 9.2 +/- 2.85% (1 s.d.). The conclusions are that, overall, the methods are reasonably satisfactory but that, with an extra effort, even closer agreement between measured and planned doses and a further limited reduction in the body dose inhomogeneity could be obtained. However, if it were thought desirable to make a substantial reduction in the dose inhomogeneity in the body and lungs, this could only be achieved with the available equipment by changing from lateral to anterior-posterior irradiation and any potential advantages of this change would have to be balanced against a likely deterioration in patient comfort and an increase in treatment set-up times.

Structural features of the extracellular portion of membrane-anchoring peptides on membrane-bound immunoglobulins

Membrane-bound immunoglobulins, mIgs, are displayed as transmembrane proteins on the surface of B cells, where they serve as antigen receptors. The mIgs are anchored to the membrane through a carboxy-terminal extension of the immunoglobulin heavy chain. Three distinct structural regions of these membrane-anchor peptides, of mouse and human mIgs, have been delineated: (1) a central conserved stretch of 25 hydrophobic, unchanged amino acid residues, which spans the membrane lipid bilayer; (2) a C-terminal hydrophilic region of 3-28 amino acids, which is intracytoplasmic; and (3) an N-terminal extracellular hydrophilic region of 13-67 amino acids, which is isotype-specific. Here we report predicted secondary and tertiary structures of the third structural region of the membrane anchoring peptide along with corroborating experimental evidence. The predictions of secondary and tertiary structure indicate that most of these regions can assume an chi-helical conformation. Circular dichroism spectroscopy of corresponding synthetic peptide confirms this essential feature. The choice of solvent and pH have dramatic effects on peptide helicity; solvent conditions consistent with a membrane-proximal environment promote helicity. Additional studies suggest that the two adjacent extracellular peptides may be stabilized through coiled-coil interactions similar to those described for some other transmembrane proteins.

Management of scales and other insect debris: occupational health hazard in a lepidopterous rearing facility

Scales and other body parts of Lepidoptera are known allergens and pose a serious health hazard for workers in rearing programs. Researchers of the Crop Science Research Laboratory (USDA-ARS), located at Mississippi State, MS, have reared lepidopterous insects since the late 1960s. Efforts have been made by them to continuously improve management of the moth scale problem and reduce allergic reactions suffered by workers. We developed strategy that requires a separate facility for housing the moth colonies, oviposition cages that facilitate exit of scales and other debris, an improved air filtration system, and sanitation procedures. The strategy used currently (coined ALERT for Advanced Lepidoptera Environmental Rearing Technology) for scale management efficiently minimizes this serious occupational hazard.

Combining ability in maize for fall armyworm and southwestern corn borer resistance based on a laboratory bioassay for larval growth

The fall armyworm, Spodoptera frugiperda (J. E. Smith), and southwestern corn borer, Diatraea grandiosella Dyar, are major insect pests of maize, Zea mays L., in the southern USA. Both insects feed extensively on leaves of plants in the whorl stage of growth. A diallel cross of seven inbred lines with different levels of susceptibility to leaf feeding damage in the field was evaluated in a laboratory bioassay for fall armyworm and southwestern corn borer larval growth. Diets were prepared from lyophilized leaf tissue of field-grown plants of the inbred lines and their 21 F1 hybrids. One inbred line, Tx601, exhibited heavy leaf damage in field tests but showed moderate resistance in the laboratory bioassay. Both general and specific combining ability were highly significant sources of variation in the inheritance of fall armyworm and south-western corn borer larval growth in the laboratory bioassay. Tx601 showed excellent general combining ability for reduced larval growth of both species.

Wheat germ hemicellulose is an absolute requirement for growth and development of the southwestern corn borer

The southwestern corn borer, Diatraea grandiosella Dyar, is a major pest of corn, Zea mays L., in the southern United States. To search for plant allelochemicals, chemically defined insect diets are commonly used, but southwestern corn borer larvae did not grow and develop unless a subnutritional amount of wheat germ was incorporated in the amino acid diet. Fractionation led to identification of hemicellulose as the active component which was then characterized. The hemicellulose permitted insect growth on a protein-free amino acid diet. Microfloral involvement was ruled out because larvae grew and developed free of intestinal microbes. Therefore, this insect has an absolute requirement for hemicellulose that has evidently not been demonstrated with other invertebrates or vertebrates. This finding is of general interest because hitherto, the contributions of hemicellulose to nutrition have generally been considered to be associated chiefly with microfloral conversion to assimilable carbohydrates. Investigations should be conducted to determine whether hemicelluloses are also important or essential for growth of vertebrates including mammals by mechanisms that may not have been considered.

In-office computerized fabrication of custom foot supports. The AMFIT System

This article familiarizes the podiatric physician with computer-aided design and manufacturing of custom orthoses in an office setting using the AMFIT System. Topics discussed include machine specifications and descriptions, data acquisition, and finishing.

Can anti-IgE be used to treat allergy?

A summary of the properties of CGP 51901 is shown in Table 3. On the basis of its binding to IgE and IgE-secreting cells and its activity in vitro and in vivo, CGP 51901 is expected to be able to decrease serum IgE by direct clearance of IgE and by reduction of the numbers and productivity of IgE-secreting cells. The end result of reduction of IgE in the circulation and on mast cells is expected to be the attenuation of IgE-mediated reactions and the improvement in allergy symptoms. The effective serum concentration of CGP 51901 is expected to be in the range 1-10 micrograms/ml. Because CGP 51901 is an antibody specific for IgE, it is expected to be highly selective in its activity. Because IgE does not appear to be essential and because CGP 51901 has been rigorously tested to confirm its non-anaphylactic nature, this treatment is not expected to have any adverse effects. Therefore, CGP 51901 is expected to be safe and to have a good probability of being effective when it is tested in human clinical trials.

MPM-12: a monoclonal antibody that predominantly stains mitotic cells and recognizes a protein kinase

The monoclonal antibody MPM-12, raised by using partially purified extract of mitotic HeLa cells as the immunogen, preferentially stains the cytoplasm of mitotic cells by indirect immunofluorescence without exhibiting any species specificity. On immunoblots, MPM-12 recognizes three bands, of 155, 88, and 68 kDa, in mitotic HeLa cell extract but only the 68-kDa band in interphase cell extract. The 68-kDa band seems to be associated with chromatin while the other two are not. All three MPM-12 reactive peptides are phosphorylated, and the phosphorylation seems to be required for MPM-12 reactivity. The MPM-12 immunocomplexes exhibit autophosphorylating and histone H1 kinase activity.

Lidocaine for the prevention of pain due to injection of propofol

Propofol has a high incidence of pain with injection, particularly into small veins. We sought to determine whether concomitant administration of lidocaine could prevent this pain. In a randomized double-blind trial, 368 women were allocated to one of four groups to receive 19 mL of propofol mixed with either 1 mL of 0.9% saline, 1 mL of 0.5% (5 mg) lidocaine, 1 mL of 1% (10 mg) lidocaine, or 1 mL of 2% (20 mg) lidocaine. The pain of injection was scored as none, mild, moderate, or severe. There was a significant reduction in the overall incidence of pain from 73% with saline to 32% with 20 mg lidocaine. A highly significant negative dose-response relationship between the dose of lidocaine and the severity of pain was demonstrable, both at induction of anesthesia and as recalled in the recovery room (P less than 0.001 for both). Lidocaine (20 mg IV) will significantly reduce the incidence and severity of pain with propofol injection, but about 6% of patients will still suffer unpleasant pain if the dorsum of the hand is used.

A new isoform of human membrane-bound IgE

The epsilon-chain of membrane-bound IgE on the surface of B lymphocytes is known to contain a membrane-anchoring peptide segment that is encoded by two membrane exons, me.1 and me.2. In analyzing pertinent segments in mRNA from human IgE-expressing B cells by using PCR methods and Northern blotting analyses, we have identified three species of mRNA of epsilon-chain with variations in the splicing of the membrane exons. The conventional species (m/s) contains the predicted me.1 and me.2; species m/1 harbors 156 extra nucleotides 5' of me.1 with unaltered reading frame; species s/t lacks me.1 and hence the segment encoding the hydrophobic transmembrane stretch and contains a shifted me.2 reading frame. Rabbit antibodies, which were prepared by immunization using a peptide of 36 amino acid residues representing an encoded segment unique to mRNA species m/l, could specifically bind to human IgE-expressing B cell lines and react with an epsilon-chain on Western immunoblots. These results indicate that there exists a previously unidentified isoform of human membrane-bound IgE.

A new isoform of human membrane-bound IgE

The epsilon-chain of membrane-bound IgE on the surface of B lymphocytes is known to contain a membrane-anchoring peptide segment that is encoded by two membrane exons, me.1 and me.2. In analyzing pertinent segments in mRNA from human IgE-expressing B cells by using PCR methods and Northern blotting analyses, we have identified three species of mRNA of epsilon-chain with variations in the splicing of the membrane exons. The conventional species (m/s) contains the predicted me.1 and me.2; species m/1 harbors 156 extra nucleotides 5' of me.1 with unaltered reading frame; species s/t lacks me.1 and hence the segment encoding the hydrophobic transmembrane stretch and contains a shifted me.2 reading frame. Rabbit antibodies, which were prepared by immunization using a peptide of 36 amino acid residues representing an encoded segment unique to mRNA species m/l, could specifically bind to human IgE-expressing B cell lines and react with an epsilon-chain on Western immunoblots. These results indicate that there exists a previously unidentified isoform of human membrane-bound IgE.

An epitope on membrane-bound but not secreted IgE: implications in isotype-specific regulation

Immunoglobulins (Igs) on the surface of B lymphocytes are isotype-specific immunological markers of the B-cell subsets expressing them. Since these membrane-bound Igs (mIgs) are antigen receptors, their interaction with antibodies could be explored for modulating the activity of specific B-cell subsets. Targeting mIgs by antibodies in vivo, however, has not been feasible because of the presence of Igs in the circulation and the frequent association of Igs with various cell types via Fc receptors. To circumvent these problems, we proposed that the extracellular portions of the membrane-anchoring segments of the heavy chains of mIgs, referred to as "mIg isotype-specific" or "migis" peptides, may provide the antigenic sites for the isotype-specific targeting of B cells in vivo. Here we describe the exemplary development of monoclonal antibodies (mAbs) recognizing this unique epitope of mIgE.

Delayed hyperbaric oxygen therapy for carbon monoxide intoxication--two case reports

The severity of signs and symptoms following carbon monoxide intoxication often does not relate to admission carboxyhaemoglobin levels. Two cases are presented with severe neurological impairment despite carboxyhaemoglobin levels of 2% and 1.7% on admission to hospital, who responded well to hyperbaric oxygen therapy. In one case, symptoms recurred several days later, but responded to further hyperbaric oxygen therapy. The role of and possible mechanism of action of late hyperbaric oxygen treatment in carbon monoxide intoxication are discussed.

Transfectomas expressing both secreted and membrane-bound forms of chimeric IgE with anti-viral specificity

Because of the lack of a cell line expressing on surface and secreting human IgE of known Ag specificity, the construction of a transfectoma line possessing such properties would be useful for studying the roles of surface IgE and the effects of anti-IgE antibodies on IgE-producing B cells. Toward this goal, the human genomic DNA segment encompassing the two exons encoding the membrane anchor peptide of epsilon-chain and their flanking regions was sequenced. Hybrid epsilon and kappa genomic DNA comprising the C regions of human epsilon- and kappa-chains and the H and L chain V regions of the murine mAb BAT123, which reacts with the gp120 envelope protein of HIV-1, were constructed. Mammalian expression vectors containing these fusion genes were used to transfect murine myeloma Sp2/0 cells, and transfectants stably expressing on surface and secreting into culture medium chimeric IgE were obtained. The chimeric IgE showed identical Ag-binding properties as the murine mAb BAT123. Acting in concert with the specific peptide Ag polyvalently coupled to a protein carrier, the chimeric antibody could induce histamine release from human blood basophils. These results demonstrate the potential utility of the transfectoma cells and the chimeric IgE in studying the roles of membrane-bound IgE and effects of anti-IgE antibodies on IgE-producing B cells.

Transfectomas expressing both secreted and membrane-bound forms of chimeric IgE with anti-viral specificity

Because of the lack of a cell line expressing on surface and secreting human IgE of known Ag specificity, the construction of a transfectoma line possessing such properties would be useful for studying the roles of surface IgE and the effects of anti-IgE antibodies on IgE-producing B cells. Toward this goal, the human genomic DNA segment encompassing the two exons encoding the membrane anchor peptide of epsilon-chain and their flanking regions was sequenced. Hybrid epsilon and kappa genomic DNA comprising the C regions of human epsilon- and kappa-chains and the H and L chain V regions of the murine mAb BAT123, which reacts with the gp120 envelope protein of HIV-1, were constructed. Mammalian expression vectors containing these fusion genes were used to transfect murine myeloma Sp2/0 cells, and transfectants stably expressing on surface and secreting into culture medium chimeric IgE were obtained. The chimeric IgE showed identical Ag-binding properties as the murine mAb BAT123. Acting in concert with the specific peptide Ag polyvalently coupled to a protein carrier, the chimeric antibody could induce histamine release from human blood basophils. These results demonstrate the potential utility of the transfectoma cells and the chimeric IgE in studying the roles of membrane-bound IgE and effects of anti-IgE antibodies on IgE-producing B cells.

Monoclonal antibodies specific for human IgE-producing B cells: a potential therapeutic for IgE-mediated allergic diseases

Monoclonal antibodies (MAbs) specific for surface antigens of lymphocytes are being used to target and deplete tumorous or normal lymphocytes in vivo. Here, we report evidence for the existence of antigenic epitopes on IgE that are accessible on IgE-secreting B cells but not on other cells bearing IgE. Among 42 murine MAbs specific for human IgE, two were shown by fluorescence flow cytometric analyses to bind to IgE-secreting cell lines but not to IgE bound to high-affinity IgE.Fc receptors (Fc epsilon RI) on basophils or low-affinity IgE receptors (Fc epsilon RII) on other cell types. Neither could they induce histamine release from basophils of various donors even under very permissive conditions. These antibodies may be useful for targeting IgE-secreting B cells in patients suffering from IgE-mediated allergies.

Preoperative transdermal hyoscine for the prevention of postoperative nausea and vomiting

In a randomised, double-blind study, a transdermal patch containing either hyoscine or placebo was applied post-auricularly in 190 adult patients under 65 year old, seven to twelve hours prior to their undergoing minor orthopaedic or plastic surgery under thiopentone/nitrous oxide/halothane general anaesthesia. In the first 24 hours after surgery 34% of patients vomited. The incidence of nausea (31% vs 54%; P less than 0.01) and the number of episodes of vomiting (66 vs 125; P less than 0.05) during the first 24 hours were significantly less with hyoscine than with placebo. The hyoscine group required fewer doses of antiemetic than the placebo group (12 vs 27; P less than 0.05). Side-effects were mild, the only difference between the two groups being the frequency of dry mouth immediately preoperatively. No differences were seen in the second 24 hours after surgery. We conclude that transdermal hyoscine is moderately effective in reducing the occurrence of postoperative nausea and vomiting following minor surgery.

Leg blood flow during total hip replacement under spinal or general anaesthesia

Calf blood flow was studied using venous occlusion impedance plethysmography during 122 total hip arthroplasties. Patients were randomly allocated to receive spinal or general anaesthesia. Blood flow was measured nine times perioperatively. In the non-surgical leg, mean blood flow rose by over 50% in both groups following anaesthetic induction, remaining significantly elevated with spinal but falling back gradually to baseline with general anaesthesia. In the surgical leg, surgical manipulations produced marked falls in flow in many patients, particularly with femoral component insertion. If this occurred, hyperaemia was commonly seen with spinal anaesthesia but rarely with general anaesthesia once the joint was relocated. Venous outflow resistance rose slightly during anaesthesia in both groups, more so with general anaesthesia. In the surgical leg, marked rises occurred with surgical manipulations, but resistance fell abruptly once the joint was relocated. No clear relationship between these observations and the occurrence of deep vein thrombosis postoperatively was established.

Mitosis-specific monoclonal antibodies block cleavage in amphibian embryos

By microinjecting monoclonal antibodies that bind specifically to mitotic and meiotic cells of a variety of species, we studied the biological activity of antigens recognized by these antibodies. The antibodies recognize a family of phosphoprotein antigens that are found throughout the cytoplasm of mitotic cells and particularly at microtubule organizing centers, including centrosomes and kinetochores. Their binding is dependent on phosphorylation of the polypeptides. Immunoglobulins were introduced into Xenopus laevis and Rana pipiens oocytes or cleaving embryos using glass micropipettes. The ability of the antibody-injected oocytes to undergo mitosis or meiosis was compared with those injected with control mouse immunoglobulins. The antibodies failed to block chromosome condensation and germinal vesicle breakdown in progesterone-treated oocytes. However, functional mitotic spindles were not assembled in cleavage stage frog embryos injected with antibodies. In vitro, the binding of the antibodies to the antigens inhibited the dephosphorylation of the antigens by alkaline phosphatase. The antibody binding to the activated microtubule organizing centers (MTOC) seems to block not only the nucleation of microtubules and the organization of the mitotic spindle, but also the dephosphorylation of proteins associated with the MTOC that normally occurs at the mitosis-G1 transition.

Deep vein thrombosis after total hip replacement. A comparison between spinal and general anaesthesia

The effect of hypobaric spinal anaesthesia or narcotic-halothane-relaxant general anaesthesia on the incidence of postoperative deep vein thrombosis was studied in 140 elective total hip replacements in a prospective randomised manner. Deep vein thrombosis was diagnosed using impedance plethysmography and the 125I fibrinogen uptake test, combined, in selected cases, with ascending contrast venography. The overall incidence of deep vein thrombosis was 20%. Nine patients (13%) developed deep vein thrombosis in the spinal group and nineteen (27%) in the general anaesthetic group (p less than 0.05). The incidences of proximal thrombosis and of bilateral thrombi were also less with spinal anaesthesia than with general anaesthesia. It is concluded that spinal anaesthesia reduces the risks of postoperative thromboembolism in hip replacement surgery. The presence of varicose veins, being a non-smoker and having a low body mass index were associated with an increased incidence of deep vein thrombosis.

Retrieval of loose peritoneal shunts by laparoscopy. Technical note

Disconnected shunt catheters free in the peritoneal cavity can be easily removed by laparoscopy with minimal opening of the peritoneum. Experience with five such cases is summarized.

Distribution of phosphorylated spindle-associated proteins in the diatom Stephanopyxis turris

Mitotic spindles isolated from the diatom Stephanopyxis turris become thiophosphorylated in the presence of ATP gamma S at specific locations within the mitotic apparatus, resulting in a stimulation of ATP-dependent spindle elongation in vitro. Here, using indirect immunofluorescence, we compare the staining pattern of an antibody against thiophosphorylated proteins to that of MPM-2, an antibody against mitosis-specific phosphoproteins, in isolated spindles. Both antibodies label spindle poles, kinetochores, and the midzone. Neither antibody exhibits reduced labeling in salt-extracted spindles, although prior salt extraction inhibits thiophosphorylation in ATP gamma S. Furthermore, both antibodies recognize a 205 kd band on immunoblots of spindle extracts. Microtubule-organizing centers and mitotic spindles label brightly with the MPM-2 antibody in intact cells. These results show that functional mitotic spindles isolated from S. turris are phosphorylated both in vivo and in vitro. We discuss the possible role of phosphorylated cytoskeletal proteins in the control of mitotic spindle function.

Movement and segregation of kinetochores experimentally detached from mammalian chromosomes

The kinetochore is a specialized structure at the centromere of eukaryotic chromosomes that attaches chromosomes to the mitotic spindle. Recently, several lines of evidence have suggested that kinetochores may have more than a passive role in the movement of chromosomes during mitosis and meiosis. Kinetochores seem to attract and 'capture' microtubules that grow from the spindle poles and microtubules may lengthen or shorten by the addition or subtraction of tubulin subunits at their kinetochore-associated ends. An attractive hypothesis is that kinetochores function as 'self-contained engines running on a microtubule track'. Here, we show that kinetochores can be experimentally detached from chromosomes when caffeine is applied to Chinese hamster ovary cells that are arrested in the G1/S phase of the cell cycle. The detached kinetochore fragments can still interact with spindle microtubules and complete all the mitotic movements in the absence of other chromosomal components. As these cells enter mitosis before DNA synthesis is completed, chromosome replication need not be a prerequisite for the pairing, alignment and segregation of kinetochores.

Selective inhibition of human ribosomal gene transcription by the morpholinyl anthracyclines cyanomorpholinyl- and morpholinyldoxorubicin

Upon incubation of cultured mammalian cells with the new anthracycline analogues cyanomorpholinyldoxorubicin and morpholinyldoxorubicin, nucleoli irreversibly segregate into their substructures which form individual portions of the nucleolar mass and characteristic electron-dense components adjacent to the nucleolonema; these changes in nucleolar ultrastructure are similar to those produced by actinomycin D (AMD). In the present study we have examined the effects of anthracycline analogues on RNA synthesis, localization of RNA polymerase I in situ, and activity of RNA polymerases in vitro, and compared these effects with those of the parent compound doxorubicin (DOX) and AMD. The results show that, following treatment with cyanomorpholinyldoxorubicin, morpholinyldoxorubicin, and AMD, but not DOX, RNA polymerase I-containing transcription complexes were reduced, reflecting the transcriptional activity of the rRNA genes. The residual RNA polymerase-containing entities were redistributed into cap-like aggregates at the nucleolar periphery. Within 30 min of exposure to cyanomorpholinyldoxorubicin, morpholinyldoxorubicin, and AMD, but not DOX, a 75-90% inhibition of RNA polymerase I activity in situ and in vitro was observed. At this early time there was no significant inhibition of nucleoplasmic RNA labeling in situ or RNA polymerases II and III activities in vitro. At later times following reincubation in drug-free medium, inhibition of all three polymerases was observed. Impairment of RNA synthesis appeared to result from drug interaction with the DNA template rather than an interaction with RNA polymerase I itself. We conclude that the morpholinyl derivatives of DOX are preferential inhibitors of ribosomal gene transcription and that they may have a mechanism of action similar to that of AMD on rRNA synthesis.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Phosphorylation of nonhistone proteins during premature chromosome condensation in a temperature-sensitive mutant, tsBN2

In tsBN2 cells, a temperature-sensitive (ts) mutant of the BHK21 cell line, with a ts-defect in its regulatory system for chromosome condensation, antigens that react with mitotic specific mouse monoclonal antibody MPM-2 were produced when premature chromosome condensation (PCC) was induced by a temperature shift. The polypeptides of antigens recognized by MPM-2 in tsBN2 cells with PCC were identical to those of antigens in mitotic cells. These antigens appeared concomitantly with chromosome condensation, which suggests that these mitotic-specific antigens may be related to chromosome condensation. As the production of mitotic-specific antigens was inhibited by W-7, a specific and potent antagonist of calmodulin, calmodulin may function in the mitotic phosphorylation of nonhistone protein.

Growth factor-mediated proliferation in B cell non-Hodgkin's lymphomas

The non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of human lymphoid tumors, primarily of B cell lineage, which appear to represent arrested stages in B lymphocyte differentiation. Control of cell proliferation is a fundamentally important but poorly understood area of study in these tumors. We have studied a representative group of B cell NHLs to assess their potential for growth factor-mediated proliferation in vitro. Our results show that purified monoclonal NHL B cells of the small cell (well-differentiated lymphocytic lymphoma, nodular poorly differentiated lymphocytic lymphoma, etc) type, that were positive for the human malignancy-associated nucleolar antigen could be stimulated by human B cell growth factor (BCGF) to proliferate in vitro. Other B cell activators such as insoluble anti-Ig and the mitogen protein A also could stimulate thymidine incorporation in the lymphoma cell populations. In vitro lymphoma cell growth could be maintained in the presence of the growth factor for up to five weeks. The large B cell type NHL, however, appeared to be refractory to in vitro stimulation by BCGF as well as other stimulators of normal B cells. These studies suggest that human B cell lymphoid tumors are not only phenotypically similar to their normal B lymphocyte counterparts, but are also sensitive in some cases, to the same types of immunoregulatory molecules that control normal lymphoid cell growth.

Phosphoproteins are components of mitotic microtubule organizing centers

Protein phosphorylation has been suggested as an important control mechanism for the events leading toward the initiation and completion of mitosis. Using a monoclonal antibody recognizing a class of phosphoproteins abundant in mitotic cells, we demonstrated the localization of a subset of these phosphoproteins to several discrete mitotic structures. Patchy immunofluorescence was present in the interphase nuclei, but a significant increase in nuclear immunofluorescence was apparent at prophase. Subsequent mitotic stages demonstrated that immunoreactive material was particularly apparent at microtubule organizing centers, namely, centrosomes, kinetochores, and midbodies. Intense centrosomal localization occurred at the prophase-prometaphase transition and persisted until the reformation of the nuclear membrane in early G1. The cytoplasm of mitotic cells also contained immunoreactive material in sharp contrast to interphase cells that exhibited no cytoplasmic fluorescent staining. Much of the diffuse immunofluorescent cytoplasmic material was removed by a brief lysis of the cells with 0.15% Triton X-100 prior to fixation. The localization of the remaining immunoreactive material after detergent lysis to mitotic microtubule organizing centers suggests that they contain phosphoprotein structural components important, perhaps, in the mitotic phase-interphase transition.

Identification of human lymphoma cells by antisera to malignancy-associated nucleolar antigens

The non-Hodgkin's lymphomas (NHL) are a diverse group of human lymphoid neoplasms that have long presented pathologists with formidable diagnostic challenges. These tumors of the immune system are thought to represent neoplastic transformations of most of the recognized stages in T and B lymphocyte ontogeny. Lymphoma cells, however, often simulate their normal lymphocytic counterparts both morphologically and cell surface phenotypically, creating difficulties in discriminating normal from neoplastic lymphocytes. We have used heteroantisera to the human malignancy-associated nucleolar antigen (HMNA) to prospectively evaluate its efficacy in identifying the morphologically neoplastic cells in NHL lesions. In 65 cases of T and B cell histopathologic types of NHL, the antisera reacted with nucleoli in the morphologically and cytogenetically 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. Normal activated lymphoid cells in vitro and growth-factor-dependent normal lymphoid cell lines also failed to express the nucleolar antigen(s). These data suggest that the HMNA is a valuable tumor cell marker for neoplastic human lymphoid cell populations and can be used with other types of cell markers for a better definition of the neoplastic cells in NHL.