Metabolism of the putative antifertility agents 3-(36)chloro-1-hydroxypropanone and its dimethyl ketal in the male rat

3-(36)Chloro-1-hydroxypropanone (CHOP), a specific inhibitor of sperm glycolysis in vitro, is rapidly metabolized by the male rat to alpha-chlorohydrin, 3-chlorolactate and the inhibitory sperm metabolite, 3-chlorolactaldehyde, presumably all being of the (S)-configuration. The dimethyl ketal of (36)Cl-CHOP [3-(36)Cl-dimethyl-CHOP] is rapidly metabolized producing identical metabolites and excreted radioactivity in urine at a similar rate. As neither compound produced diuresis, glucosuria or induced the formation of spermatocoeles, conditions associated with related male antifertility and antiglycolytic agents, they could represent an alternative means of producing (S)-3-chlorolactaldehyde within spermatozoa in vivo.

Functional discovery via a compendium of expression profiles

Ascertaining the impact of uncharacterized perturbations on the cell is a fundamental problem in biology. Here, we describe how a single assay can be used to monitor hundreds of different cellular functions simultaneously. We constructed a reference database or "compendium" of expression profiles corresponding to 300 diverse mutations and chemical treatments in S. cerevisiae, and we show that the cellular pathways affected can be determined by pattern matching, even among very subtle profiles. The utility of this approach is validated by examining profiles caused by deletions of uncharacterized genes: we identify and experimentally confirm that eight uncharacterized open reading frames encode proteins required for sterol metabolism, cell wall function, mitochondrial respiration, or protein synthesis. We also show that the compendium can be used to characterize pharmacological perturbations by identifying a novel target of the commonly used drug dyclonine.

Widespread aneuploidy revealed by DNA microarray expression profiling

Expression profiling using DNA microarrays holds great promise for a variety of research applications, including the systematic characterization of genes discovered by sequencing projects. To demonstrate the general usefulness of this approach, we recently obtained expression profiles for nearly 300 Saccharomyces cerevisiae deletion mutants. Approximately 8% of the mutants profiled exhibited chromosome-wide expression biases, leading to spurious correlations among profiles. Competitive hybridization of genomic DNA from the mutant strains and their isogenic parental wild-type strains showed they were aneuploid for whole chromosomes or chromosomal segments. Expression profile data published by several other laboratories also suggest the use of aneuploid strains. In five separate cases, the extra chromosome harboured a close homologue of the deleted gene; in two cases, a clear growth advantage for cells acquiring the extra chromosome was demonstrated. Our results have implications for interpreting whole-genome expression data, particularly from cells known to suffer genomic instability, such as malignant or immortalized cells.

Early outcomes after allogeneic stem cell transplantation for leukemia and myelodysplasia without protective isolation: a 10-year experience

Although it is common practice to use some form of isolation to protect allogeneic stem cell transplant patients from infection, the necessity for these practices in all environments has not been demonstrated. The current study evaluated patterns of infection and 100-day transplant-related mortality in 288 patients with myelodysplasia and leukemia transplanted without isolation. Patients were allowed out of hospital at any time within constraints of the medication schedule. Fever, foci of infection, and positive cultures within 28 days and death within 100 days because of the transplant procedure were recorded. Fever occurred in 57% of patients, and 10% had a clinical or radiographic focus of infection. Most infections were apparently endogenous; blood cultures from 24% of recipients grew organisms, 87% of which were gram-positive bacteria. Four patients (1%) died with aspergillus infection in circumstances indicating that isolation would not have been helpful. Twenty percent of patients remained without evidence of infection throughout. Transplant-related mortality at 100 days was 1% for 108 patients with early leukemia receiving transplants from matched siblings. For patients at higher risk, by virtue of donor and/or disease status, mortality was 21%. These figures compare favorably with those reported to the International Bone Marrow Transplant Registry, the majority of patients having been subjected to some form of isolation. We conclude that allogeneic stem cell transplantation can be safely performed in some environments without confining patients continuously to the hospital.

Substrates for endogenous metabolism by mature boar spermatozoa

Washed boar spermatozoa incubated in the absence of exogenous substrates maintained a high energy charge potential (ECP) for at least 10 h. Addition of bromopyruvate, an inhibitor of stage 2 of the glycolytic pathway, at any time during the incubation caused an immediate decrease in the ECP, indicating that the mobilization of endogenous compounds requires this section of the pathway for the production of lactate, the major mitochondrial substrate for ATP production. Some of the sources of the metabolic substrates have been identified, by NMR and metabolic studies, as di- or triglycerides, to produce glycerol, and membrane phospholipids for the production of glycerol 3-phosphate. Acetylcarnitine contributes acetyl groups early in the incubation; glycerylphosphorylcholine is degraded to glycerol 3-phosphate and choline after about 5 h, and acetate also accumulates after about 5 h. The presence of phosphorylcholine and phosphorylethanolamine later in the incubation indicates that phospholipids are also degraded to glycerol.

Substrates for endogenous metabolism by mature boar spermatozoa

Washed boar spermatozoa incubated in the absence of exogenous substrates maintained a high energy charge potential (ECP) for at least 10 h. Addition of bromopyruvate, an inhibitor of stage 2 of the glycolytic pathway, at any time during the incubation caused an immediate decrease in the ECP, indicating that the mobilization of endogenous compounds requires this section of the pathway for the production of lactate, the major mitochondrial substrate for ATP production. Some of the sources of the metabolic substrates have been identified, by NMR and metabolic studies, as di- or triglycerides, to produce glycerol, and membrane phospholipids for the production of glycerol 3-phosphate. Acetylcarnitine contributes acetyl groups early in the incubation; glycerylphosphorylcholine is degraded to glycerol 3-phosphate and choline after about 5 h, and acetate also accumulates after about 5 h. The presence of phosphorylcholine and phosphorylethanolamine later in the incubation indicates that phospholipids are also degraded to glycerol.

Chemical interference with sperm metabolic pathways

During the 1960s, the quest for a simple non-steroidal chemical possessing male antifertility activity culminated with the discovery of the activity of alpha-chlorohydrin in 1970. Investigations into the mechanism of action of this compound revealed that it was affecting the glycolytic pathway within mature spermatozoa through its conversion to an inhibitory metabolite. Use of these and other simple chemical inhibitors has subsequently led to a clearer understanding of the metabolic pathways involved in the generation of ATP, which is necessary for sperm motility. Mature boar spermatozoa from the cauda epididymidis are almost totally reliant on the glycolytic pathway, not necessarily for the immediate generation of ATP, but for the ultimate production of lactate, which appears to be the sole substrate used for the mitochondrial production of ATP. The only exogenous substrates that support lactate production in vitro are fructose, glucose, glycerol and glycerol 3-phosphate and when these substrates are plentiful, there is evidence that compounds can be retained as such or as intermediates of the glycolytic pathway. When exogenous substrates are limited, the cells have the capability to mobilize endogenous compounds and to maintain the continuous synthesis of ATP.

Allogeneic blood stem cell and bone marrow transplantation for acute myelogenous leukemia and myelodysplasia: influence of stem cell source on outcome

We have compared the outcomes of 87 patients with acute myelogenous leukemia (AML) and myelodysplasia (MDS) receiving matched sibling transplants with stem cells from peripheral blood (blood cell transplant, BCT) or bone marrow (BMT). In good risk patients (AML in CR1) granulocytes recovered to 0.5 x 10(9)/l a median of 14 days after BCT compared with 19 days after BMT (P < 0.0001). For patients with poor risk disease (AML beyond CR1 and MDS) corresponding figures were 16 vs 26 days (P < 0.0001). Platelet recovery to 20 x 10(9)/l was also faster after BCT (good risk 12 vs 20 days, P < 0.0001; poor risk 17 vs 22 days, P = 0.04). Red cell transfusions were unaffected by cell source, but BCT recipients required less platelet transfusions (good risk 1 vs 5, P = 0.002; poor risk 5 vs 11, P = 0.004). Blood cell transplants resulted in more chronic GVHD (86% vs 48%, P = 0.005) and a significantly higher proportion of recipients with KPS of 80% or less (48% vs 5%, P = 0.004). Disease-free survival at 4 years was 23% for both groups of poor risk patients but outcome in good risk patients was better after BCT (93% vs 62%, P = 0.047) related mainly to less relapse. While disease-free survival may be better after BCT than BMT for AML in CR1, quality of life may be relatively impaired.

A re-appraisal of the post-testicular action and toxicity of chlorinated antifertility compounds

Some 30 years ago, alpha-chlorohydrin and some analogues were considered as close to the ideal contraceptive which acted rapidly and reversibly on the post-testicular maturation of spermatozoa. Despite their early promise, research funding was withdrawn only 5 years later because of what were considered to be unacceptable side-effects in primates. The literature on the toxic effects of these contraceptive agents was reviewed and was found to be wanting in respect to the rigour of scientific methods applied (impure compounds were used, inappropriate target populations were studied, excessive doses were employed, abstracts were cited from which no full publications subsequently arose). These compounds remain the closest approach yet to non-hormonal contraceptives for males and have led to the synthesis of related compounds which have a similar antifertility action but with much diminished toxicity. If toxicity remains a problem, a range of other compounds now known to have a similar antifertility action, should be investigated.

Superior autologous blood stem cell mobilization from dose-intensive cyclophosphamide, etoposide, cisplatin plus G-CSF than from less intensive chemotherapy regimens

The study purpose was to determine if G-CSF plus dose-intensive cyclophosphamide 5.25 g/m2, etoposide 1.05 g/m2 and cisplatin 105 mg/m2 (DICEP) results in superior autologous blood stem cell mobilization (BSCM) than less intensive chemotherapy. From January 1993 until May 1997, 152 consecutive patients with non-Hodgkin's lymphoma (n = 55), breast cancer (n = 47), Hodgkin's disease (n = 14), multiple myeloma (n = 9), AML (n = 9), or other cancers (n = 18) initially underwent BSCM by one of three methods: Group 1: G-CSF alone x 4 days (n = 30). Group 2: disease-oriented chemotherapy, dosed to avoid blood transfusions, followed by G-CSF starting day 7 or 8, and apheresis day 13 or 14 (n = 82). Group 3: DICEP days 1-3, G-CSF starting day 14, and apheresis planned day 19, 20 or 21 (n = 40). A multivariate analysis was performed to determine which factors independently predicted BSCM. The median peripheral blood CD34+ (PB CD34+) cell count the morning of apheresis linearly correlated with the number of CD34+ cells removed per litre of apheresis that day. The median PB CD34+ cell count and median CD34+ cells x 10(6) removed per litre of apheresis were highest for Group 3, intermediate for Group 2, and lowest for Group 1. By multivariate analysis, mobilization group (3 > 2 > 1), disease other than AML, no prior melphalan or mitomycin-C, and less than two prior chemotherapy regimens predicted better BSCM. Out of 15 Group 3 patients who had infiltrated marrows, 11 had no detectable cancer in marrow and apheresis products after DICEP. These data suggest that DICEP results in superior BSCM than less intensive chemotherapy regimens.

Stimulant use in sports

The authors provide an overview of the topic of stimulant use in psychiatric sports medicine. They address the following areas: 1) the history of stimulant use in sports; 2) recent events related to the use of stimulants in sports, including a new stimulant used at the 1996 Olympic competition in Atlanta, GA; 3) ergogenic or ergolytic (i.e., performance-impairing) potential of several major categories of stimulants, including amphetamines, beta2 agonists, caffeine, and cocaine; 4) review of how the brain reward circuit is affected by stimulants; 5) individual factors that induce athletes to utilize stimulants; and 6) sports organizational factors that induce athletes to use stimulants.

Guidelines for organisation and management of external quality assessment using proficiency testing. Expert Panel on Cytometry of the International Council for Standardization in Haematology

This document is intended to assist towards the WHO objective that external quality assessment (EQA) schemes be established at national and/or regional levels world-wide. Quality assurance is defined as all steps taken by the director of a laboratory to ensure reliability of laboratory results and to increase accuracy, reproducibility and between-laboratory comparability. This includes the use of internal quality control procedures and participation in external quality assessment. Internal quality control provides the means for evaluation of analytic test results at the time of testing in order to decide whether they are reliable enough to be released to the requesting clinicians. EQA, on the other hand, refers to a system of retrospective and objective comparison of results from different laboratories by means of proficiency testing (PT) organised by an external agency. The main purpose is to establish between-laboratory and between-method (including between-instrument) comparability, and agreement with a reference standard where one exists. Internal quality control and EQA complement each other and must never be considered as alternatives.

Triosephosphate metabolism by mature boar spermatozoa

Boar sperm rapidly interconverted dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, produced fructose-1,6-bisphosphate, approximately equilibrium concentrations of fructose 6-phosphate and glucose 6-phosphate but not glycerol or glycerol 3-phosphate. In the presence of 3-chloro-1-hydroxypropanone, an inhibitor of stage 2 of the glycolytic pathway, the triosephosphates were metabolized faster, produced less fructose-1,6-bisphosphate, fructose 6-phosphate and glucose 6-phosphate, but not glycerol or glycerol 3-phosphate. This suggests that these cells may have the capacity to convert glycolytic intermediates into a storage metabolite to conserve carbon atoms for the eventual synthesis of lactate.

Metabolic activity of hypotonically treated mature boar spermatozoa

Treatment of washed boar sperm with hypotonic phosphate buffer removed the acrosome, disrupted the cytoplasmic membrane and almost completely separated the heads from the mid piece-tail segment. As assessed by oxygen uptake studies and their ability to oxidize 14C-labelled substrates to 14CO2, hypotonically-treated cells exhibit low glycolytic activity yet mitochondrial activity remains high. Both lactate and glycerol 3-phosphate underwent oxidation and these substrates continued to be metabolized by this preparation which had been stored for up to 10 days at 4 degrees C. Such preparations may be of assistance in the investigation of the biochemistry of boar sperm mitochondria.

Single-agent high-dose melphalan salvage therapy for Hodgkin's disease: cost, safety, and long-term efficacy

BACKGROUND

Few data are available on the cost, safety, and long-term efficacy of single-agent high-dose melphalan (HDM) followed by autologous bone marrow (ABMT) or blood stem cell (ABSCT) transplantation in the salvage therapy of Hodgkin's disease (HD).

PATIENTS AND METHODS

From February 1981 to September 1996, 23 patients with relapsed (n = 15) or refractory (n = 8) HD received salvage therapy with HDM 140-200 mg/m2 followed by non-cryopreserved ABMT (n = 18) or cryopreserved ABSCT (n = 5). The cost of HDM/ABSCT in 1996, from initial consultation until transfer back to referring physician, was determined and compared to the estimate costs of two multi-agent regimens commonly used for HD.

RESULTS

HDM was well tolerated with no early transplant-related mortality. The five-year overall and progression-free survival rates were 52% and 50%, respectively. The average total cost in Canadian funds of HDM/ABSCT in 1996 was $34,400/patient. This cost was estimated to be $4,700-6,800 cheaper per patient than the multi-agent high-dose regimens.

CONCLUSION

These data suggest that HDM is safe, feasible, active, and reasonably inexpensive salvage therapy for patients with relapsed/refractory HD.

Endogenous energy production by mature boar spermatozoa

When incubated in the absence of exogenous substrates, washed boar spermatozoa maintained a high energy charge potential (ECP) for at least 5 h. Addition of 3-chloro-1-hydroxypropanone, an inhibitor of triosephosphate isomerase and glyceraldehyde 3-phosphate dehydrogenase, at any time caused the ECP to decline and fructose-1,6-bisphosphate, dihydroxyacetone phosphate and glycerol to accumulate. There appear to be two endogenous substrates that are degraded ultimately to produce the triosephosphates which allow the cells to produce lactate for the mitochondrial synthesis of ATP. One substrate generates minor amounts of glycerol 3-phosphate whereas the other substrate degrades to glycerol and may be di-glycerides, or tri-glycerides, or both.

The impact of pre-clerking clinics on surgical operation cancellations: a prospective audit

Pre-clerking of all patients undergoing elective general surgical operations was introduced at our hospital in an attempt to reduce an unacceptably high operation cancellation rate. A prospective audit has been performed on the effect of this policy on the cancellation rate. Before the introduction of pre-clerking there was a marked seasonal variation in the number of patients who failed to attend for surgery, which could be explained by absence on holiday. This seasonal variation disappeared after the start of pre-clerking clinics, but there has been no reduction in the number of cancellations for medical reasons.

Metabolism of 36Cl-ornidazole after oral application to the male rat in relation to its antifertility activity

1. The antimycotic ornidazole (a male antifertility agent in rats) was synthesized incorporating 36Cl in the chloropropyl sidechain and its metabolism was investigated in the male rat after oral ingestion. 2. Blood levels of radioactivity were low over the first 24 h and there was no tissue accumulation of radioactivity over 48 h. 3. Most of the excreted radioactivity (20% of the ingested dose) appeared in the urine within the first 24 h. 4. Three major compounds were detected in 0-24-h urine samples and were characterized as ornidazole (13% of total radioactivity), Cl- (22%) and 3-chlorolactate (30%), the oxidation product of 3-chlorolactaldehyde. 5. No polyuria or glucosuria was observed following the oral administration of ornidazole, suggesting that any (R)-3-chlorolactate produced was insufficient to affect renal metabolism. 6. Conversion of ornidazole initially to (R, S)-alpha-chlorohydrin or ultimately to the glycolytic inhibitor (S)-3-chlorolactaldehyde could explain its antifertility action in the male rat.

Metabolism of lactate by mature boar spermatozoa

Boar sperm oxidatively metabolized fructose, glucose, glycerol, glycerol 3-phosphate and lactate to CO2 but pyruvate produced only small amounts of CO2 and this was almost completely prevented when endogenous glycolytic metabolism was inhibited. Lactate was the preferred substrate over fructose, glycerol and glycerol 3-phosphate and when lactate was offered in the presence of pyruvate, lactate was preferentially oxidized to CO2. The rate of oxidation of fructose, glycerol and glycerol 3-phosphate was approximately halved in the presence of equi-molar concentrations of lactate and the metabolism of lactate was progressively decreased in the presence of increasing concentrations of mersalyl, an inhibitor of lactate transport. Sperm maintained a high energy charge potential when incubated with lactate as substrate in the presence or absence of bromopyruvate, an inhibitor of endogenous glycolytic metabolism. This evidence confirms that it is lactate, rather than pyruvate, that enters the mitochondria thereby constituting a lactate-pyruvate transport system in these cells for regenerating cytoplasmic nicotinamide adenine dinucleotide (NAD+). Electrophoretic examination of the lactate dehydrogenase isozymes from sperm and several other tissues of the boar showed that sperm contained almost entirely an isozyme which was not present in the other tissues.

Diurnal change of blood count analytes in normal subjects

Short-term, within one 24-hour day (diurnal period) within-person changes of the principal blood count analytes in healthy subjects were studied at three major institutions. The results from each test site were indistinguishable and were therefore combined to make a database of 96 healthy subjects. Analytical imprecision of each analyte was subtracted from the total observed variation to give true diurnal change. Each analyte showed characteristic changes. As would be expected, cellular properties of erythrocytes, such as MCV (mean cell volume) and MCH (mean cell hemoglobin) showed negligible change. The red cell count, hematocrit, and hemoglobin showed changes that were consistent with fluid balance change. Total white cell count and some differential count components showed major changes that raised questions of the confidence limits of clinical decision levels and the validity of commonly used reference intervals. Platelet count changes were typically less than analytic imprecision, suggesting the need for improvement in this aspect of analyzer performance.

GLD-1, a cytoplasmic protein essential for oocyte differentiation, shows stage- and sex-specific expression during Caenorhabditis elegans germline development

GLD-1, a putative RNA binding protein, is essential for oocyte development in Caenorhabditis elegans. A gld-1 null mutation abolishes hermaphrodite oogenesis and confers a tumorous germline phenotype in which presumptive female germ cells exit the meiotic pathway and return to the mitotic cell cycle. Here we demonstrate that gld-1(null) germ lines express female-specific, but not male-specific, molecular markers, indicating that gld-1 acts downstream of sexual fate specification to regulate oocyte differentiation. Immunolocalization studies identify GLD-1 as a cytoplasmic germline protein that displays differential accumulation during germline development. First, germ cells that are in the mitotic cell cycle contain low levels of GLD-1 that likely reflect a nonessential gld-1 function (negative regulation of proliferation in the mitotic germ line) revealed in previous genetic studies. Second, entry of presumptive oocytes into the meiotic pathway is accompanied by a strong increase in GLD-1 expression/accumulation. GLD-1 levels are high through the pachytene stage but fall to background as germ cells exit pachytene and complete oogenesis. The meiotic prophase accumulation pattern is consistent with GLD-1's essential role in oocyte differentiation, which may be to repress the translation of a subset of maternal RNAs synthesized during early oogenesis until late oogenesis when GLD-1 is absent.

Glycerol 3-phosphate dehydrogenase of boar spermatozoa: inhibition by alpha-bromohydrin phosphate

Boar spermatozoa incubated with glycerol 3-phosphate as substrate produced CO2 and an accumulation of dihydroxyacetone phosphate and fructose-1,6-bisphosphate. The rate of oxidation of glycerol 3-phosphate was decreased, as was the production of CO2 and the two glycolytic intermediates, in the presence of (R,S)-alpha-bromohydrin phosphate. In the presence of inhibitors of stage two of the glycolytic pathway, CO2 production was prevented, there was a marked increase in the concentration of the glycolytic intermediates but the rate of metabolism of the substrate was unaffected. Oxygen consumption by spermatoza incubated with glycerol 3-phosphate was unaffected in the presence of rotenone, whereas it was decreased when lactate was offered as the substrate. The results reported here confirm that in boar spermatozoa glycerol 3-phosphate dehydrogenase is an FAD-linked enzyme that is inhibited by (R,S)-alpha-bromohydrin phosphate in, possibly, a competitive manner.

Metabolism of glycerol 3-phosphate by mature boar spermatozoa

Under anaerobic conditions boar spermatozoa metabolized fructose and glucose to lactate but did not produce ATP to the extent of that produced under aerobic conditions; the ketogenic amino acids leucine, tryptophan, phenylalanine and tyrosine were not oxidatively metabolized. Glycerol 3-phosphate was metabolized rapidly in the presence or absence of the glycolytic inhibitor, 3-chloro-1-hydroxypropanone (CHOP). In the absence of CHOP, glycerol 3-phosphate was converted to CO2, lactate, glucose 6-phosphate and fructose 6-phosphate, and ATP was produced. In the presence of CHOP, glycerol 3-phosphate did not produce CO2, lactate or ATP, but formed fructose 1,6-bisphosphate and dihydroxyacetone phosphate. With dihydroxyacetone phosphate as substrate, fructose 1,6-bisphosphate, lactate, glucose 6-phosphate, fructose 6-phosphate and ATP were produced. Accumulation of glucose 6-phosphate and fructose 6-phosphate from glycerol 3-phosphate appeared to depend on the production of ATP; if ATP was not produced, dihydroxyacetone phosphate and fructose 1,6-bisphosphate accumulated. The conversion of glycerol 3-phosphate to glycolytic intermediates appeared to be a mechanism for the conversion of substrates for the ultimate production of lactate.

Transcutaneous electric nerve stimulation (TENS) during distension shoulder arthrography: a controlled trial

Transcutaneous electric nerve stimulation (TENS) is a safe and simple form of analgesia but is little used as an adjunct to local anaesthesia during routine procedures. This trial investigates the use of TENS in the radiology department using distension shoulder arthrography for 'frozen shoulder', a moderately painful procedure, as a model. Sixty patients with a clinical diagnosis of 'frozen shoulder' were randomised to receive high-intensity TENS, low-intensity TENS or to act as controls. A standard procedure was then performed. Following the procedure patients completed a visual analogue pain scale. Mean recorded pain levels were lower in the TENS groups with a 50% difference between the high-intensity group and a 38% difference between the low-intensity group as compared to control (difference statistically significant P < 0.01 and P < 0.05, respectively). TENS was well tolerated by patients. The 50% reduction in mean pain levels supports the use of TENS for routine painful procedures.

Renal and spermatozoal toxicity of alpha-bromohydrin, 3-bromolactate and 3-bromopyruvate

(R,S)- and (R)-3-Bromopropan-1,2-diol (alpha-bromohydrin) produced diuresis and glucosuria when administered to male rats but had no effect on the metabolic activity of rat kidney tubules in vitro. The oxidation products (R,S)-3-bromolactate and 3-bromopyruvate produced brief phases of diuresis but not glucosuria, and severely inhibited the metabolic activity of rat kidney tubules in vitro. alpha-Bromohydrin had no effect on the metabolic activity of boar spermatozoa whereas the oxidation products severely affected mitochondrial metabolism. 3-Bromopyruvate also inhibited boar spermatozoal glyceraldehyde 3-phosphate dehydrogenase.

The anti-glycolytic activity of 3-bromopyruvate on mature boar spermatozoa in vitro

Mature epididymal boar spermatozoa converted fructose, glycerol and glycerol-3-phosphate to carbon dioxide, but in the presence of 0.5 mM 3-bromopyruvate, these oxidations were inhibited while that of lactate was unaffected. Inhibition of the oxidation of these substrates results in a decrease in the content of ATP and the accumulation of dihydroxyacetone phosphate and fructose-1,6-bisphosphate. Examination of the activities of the enzymes within stage two of the glycolytic pathway showed that glyceraldehyde-3-phosphate dehydrogenase and 3-phosphoglycerate kinase were immediately inhibited by 3-bromopyruvate in a competitive manner. We now report the action of 3-bromopyruvate on the metabolic activity of boar spermatozoa. At a concentration of 0.5 mM, this compound selectively inhibits stage two of the glycolytic pathway and becomes yet another specific inhibitor of spermatozoal metabolism.

Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

To help resolve uncertainties as to the most appropriate weighting factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 +/- 0.5 to 1.3 +/- 0.3. A best estimate of the RBE for this experiment was about 1.2 +/- 0.3. A wR value of 1 would thus appear to be more appropriate than a wR of 2 for tritium beta rays.

Microvessel endothelial cells and pericytes increase proliferation and repress osteoblast phenotypic markers in rat calvarial bone cell cultures

To investigate the influence of microvessel cells on osteoblasts, we exposed osteoblast-enriched cultures of rat calvarial cells to cultured endothelial cells and pericytes using feeder-layer co-cultures, co-culture dish inserts, and conditioned media experiments. When co-cultured with growth-arrested feeder-layers of endothelial cells or pericytes for 10 days, bone cell cultures showed an increase in cell number and reduction in alkaline phosphatase activity. The response of bone cells to endothelial cells was nearly twice their response to pericytes. A similar response was demonstrated by exposure to microvessel cells in co-culture dish inserts and by exposure to media conditioned by microvessel cells. In long-term cultures of bone cells, the levels of osteocalcin and the number of mineralized nodules both were reduced by exposure to media conditioned by the microvessel cells. Transient exposure to conditioned media from the microvessel cell cultures for 3 days, during the period from initial plating to cell confluence, produced nearly the same effect on the cultures of bone cells as did continuous exposure to these conditioned media. The influence of isolated microvessel cells on osteoblast-enriched calvarial cells was found to be primarily mitogenic, mediated by soluble factors, independent of cell contact, and a cause of prolonged reduction in the expression of early and late markers of the osteoblast phenotype.

Mutations in gld-1, a female germ cell-specific tumor suppressor gene in Caenorhabditis elegans, affect a conserved domain also found in Src-associated protein Sam68

The gld-1 gene of Caenorhabditis elegans is a germ-line-specific tumor suppressor gene that is essential for oogenesis. We have cloned the gld-1 gene and find that it encodes two proteins that differ by 3 amino acids. The predicted proteins contain a approximately 170-amino-acid region that we term the GSG domain (GRP33/Sam68/GLD-1), on the basis of significant similarity between GLD-1, GRP33 from shrimp, and the Src-associated protein Sam68 from mouse (also described as GAPap62 from humans). A conserved structural motif called the KH domain is found within the larger GSG domain, suggesting a biochemical function for GLD-1 protein in binding RNA. The importance of the GSG domain to the function of gld-1 in vivo is revealed by mutations that affect 5 different conserved GSG domain residues. These include missense mutations in an absolutely conserved residue of the KH domain that eliminate the tumor suppressor function of gld-1.

Absolute versus proportional differential leucocyte counts

Comparison of absolute (cells x 10(9)/l) leucocyte differential counts with proportional (percentage) counts from the same stained films demonstrates significant disparities between these two methods of reporting results. Within reference intervals the disparities are modest but become significant in specimens with distributional abnormalities. Although neither method of reporting is formally espoused in this communication, it is suggested that use of the absolute count is more likely to provide diagnostic support.

Inhibition of glycolysis in boar spermatozoa by 1,6-dichloro-1,6-dideoxy-D-fructose

The dichloro-analogue of D-fructose 1,6-bisphosphate, 1,6-dichloro-1,6-dideoxy-D-fructose, is a weak substrate for boar sperm aldolase which converts it to (S)-3-chlorolactaldehyde and 3-chloro-1-hydroxypropanone in vitro. Production of these chloro-trioses leads to the strong inhibition of glyceraldehyde-3-phosphate dehydrogenase, the weak inhibition of triosephosphate isomerase and the transient inhibition of aldolase.

Lupus anticoagulant and HELLP syndrome complicated by placental abruption, hepatic, dermal and adrenal infarction

Pregnancy complicated by the HELLP syndrome and antiphospholipid antibodies has not previously been documented. The patient suffered a significant placental abruption, hepatic, adrenal and cutaneous infarctions, and ongoing adrenal insufficiency. Attention is drawn to the serious clinical potential of this association.

The aetiology and distinguishing features of solitary spinal hot spots on planar bone scans

PURPOSE

To determine the aetiology of solitary spinal hot spots on planar bone scans and to determine which radiographic and scintigraphic features aid in distinguishing benign from malignant lesions.

MATERIALS AND METHODS

81 bone scans showing a solitary hot spot in the spine were identified. Aetiology was determined in 73 based on imaging and clinical findings, including clinical follow-up. The location of the hot spot was classified as paravertebral (related to the lateral spinal margin), panvertebral (diffuse uptake confined within a vertebra), hemivertebral (uptake confined between the midline and lateral spinal margin) or complex (all others).

RESULTS

The aetiology of the spinal hot spot was benign in 55 patients and malignant in 18. The latter all belonged to the subgroup of 42 patients with a known malignancy. Only eight of the 18 malignant cases had suggestive plain radiographic findings. There was no significant relationship between aetiology and age. The spinal level of the hot spot was cervical in three (all benign), thoracic in 16 (eight benign) and lumbar in 54 (44 benign). The hot spot was paravertebral in 21 (all benign), panvertebral in 24 (20 benign), hemivertebral in 13 (10 benign) and complex in 15 (only four benign).

CONCLUSIONS

Most (75%) solitary spinal hot spots are benign, and even in patients with known malignancy just over half (57%) are benign. Malignant lesions are often (56%) radiographically occult. Thoracic or complex hot spots are more likely to be malignant while paravertebral hot spots are characteristically benign. These features may be helpful in distinguishing benign and malignant lesions in patients with a known malignancy and unremarkable radiographs. Other scintigraphic features are unhelpful in distinguishing benign from malignant lesions.

Inhibition of glyceraldehyde 3-phosphate dehydrogenase in boar spermatozoa by bromohydroxypropanone

In the presence of 3-bromo-1-hydroxypropanone (BOP), cauda epididymal sperm obtained from mature boars produced a carbonyl compound which is assumed to be (S)-3-bromolactaldehyde. Glyceraldehyde 3-phosphate dehydrogenase was rapidly inhibited which resulted in the accumulation of dihydroxyacetone phosphate and fructose-1,6-bisphosphate, and no accumulation of lactate when fructose was the substrate. The energy charge potential of the cells declined in the presence of BOP when either fructose or glycerol were substrates. It is suggested that BOP is transformed into (S)-3-bromolactaldehyde, which is the actual inhibitor of glyceraldehyde 3-phosphate dehydrogenase, thus demonstrating BOP to be the first brominated chemical to have an anti-glycolytic action on mature sperm in vitro.

Mycobacterium avium complex (MAC) osteomyelitis and septic arthritis in an immunocompetent host

We describe a case of Mycobacterium avium complex (MAC) osteomyelitis and septic arthritis in an immunocompetent man. Infection was derived from a chainsaw injury sustained on the lateral aspect of the ankle 13 years earlier, and had spread through the bone, joint and soft tissue emerging at the medial aspect. This was successfully treated with surgical debridement, drainage, arthrodesis and 18 months of chemotherapy consisting of clarithromycin, rifampicin, ethambutol, and ciprofloxacin with an initial 2 weeks of amikacin. Infections with this organisms are generally associated with immunocompromised states, particularly advanced AIDS. However, our patient illustrates that atypical mycobacterial infections must also be considered in immunocompetent patients who have a prolonged clinical course and an appropriate potential source of infection.

Inhibition of glycolysis in boar spermatozoa by alpha-chlorohydrin phosphate appears to be mediated by phosphatase activity

(R,S)-alpha-chlorohydrin-1-phosphate, previously shown to have no anti-glycolytic activity on mature boar sperm in vitro, is a substrate for acid and/or neutral phosphatase(s) that are associated with washed sperm. The high phosphatase activity hydrolyses the ester to alpha-chlorohydrin which undergoes oxidation to (S)-3-chlorolactaldehyde, a specific inhibitor of sperm glyceraldehyde-3-phosphate dehydrogenase and triosephosphate isomerase, thereby exhibiting an anti-glycolytic action.

Primary peristalsis is the major acid clearance mechanism in reflux patients

This study examined the clearance of gastric acid from the oesophagus in ambulant patients with gastro-oesophageal reflux. Eighteen patients with proved reflux disease were studied, nine with (group 1) and nine without (group 2) endoscopic oesophagitis. Oesophageal pressure and pH were recorded over 24 hours. Pressures were measured by a probe with five sensors: a 5 cm long sensor in the lower oesophageal sphincter, three sensors in the body of the oesophagus, and one at the pharynx to detect swallowing. Oesophageal pH was monitored 5 cm above the lower oesophageal sphincter. Manometric activities were classified as either peristaltic or ineffective. The latter included simultaneous, non-transmitted, and low amplitude peristaltic contractions. A reflux episode was defined as starting when pH fell to less than 4 and ending when the pH rose to 5. When the rise to pH 5 took place in three or more discrete steps after motor responses to gastro-oesophageal reflux, the pH steps were labelled as initial change (I), middle changes (M), and last change (L). A total of 595 episodes of gastro-oesophageal reflux and 1626 associated motor events were analysed. Of these, 1331 (81.9%) were classed as primary peristaltic activity, 174 (10.7%) as primary ineffective activity, 46 (2.8%) as secondary peristaltic activity, and 75 (4.6%) as secondary ineffective activity. There were no significant differences in initial change (p > 0.05), middle changes (p > 0.05), and last change (p > 0.05) between group 1 and group 2. In all patients, the successive changes of pH in response to motor activity were significantly different (p = 0.0001) between initial, middle, and last changes. Last change was significantly higher when compared with initial (p=0.001) and middle changes (p<0.001). Primary oesophageal peristalsis was the most frequent motor response to gastro-oesophageal reflux. The last motor activity during reflux showed the greatest change in pH.

Addition of low-dose folinic acid to a methotrexate/cyclosporin A regimen for prevention of acute graft-versus-host disease

A study was performed to determine whether the addition of folinic acid to a combination of methotrexate (MTX) and cyclosporin A (CsA) after allogeneic bone marrow transplantation (BMT) could improve tolerance to the regimen without inhibiting its ability to prevent graft-versus-host disease (GVHD). Sixty-nine adult BMT patients received CsA plus MTX 15 mg/m2 on day 1 and 10 mg/m2 on days +3, +6 and +11. Folinic acid 5 mg was started 24 h after each MTX dose and continued 6 hourly until 12 h before the next dose of MTX. The median age of the group was 37 years and 13 patients (19%) received bone marrow from mismatched and/or unrelated donors. No MTX doses were omitted or modified. Grade II-IV acute GVHD occurred in 18 patients (29%) and chronic GVHD in 35 of 56 (64%) patients at risk. There were no cases of grade > or = III stomatitis. Transplant-related mortality was 7% before 100 days and 20% overall (9% for low risk leukaemia) with a median follow-up of 41 months (range 24-88 months). This regimen of folinic acid rescue may contribute to a well tolerated GVHD prophylaxis protocol with reasonably low BMT-related mortality. Our results suggest that the ability of MTX to prevent acute GVHD is not abrogated by folinic acid given in this way.

Case report: thromboembolism during transfemoral arteriography--radiographic demonstration with histopathological correlation

Thromboembolism is a well described complication of transfemoral arteriography. Its origin and course is rarely demonstrated. We describe a case of thromboembolism with histopathological correlation demonstrating the origin and course during contrast injection.

A deep lateral femoral notch as a sign of acutely torn anterior cruciate ligament

Anterior cruciate ligament (ACL) tears are frequently associated with abnormalities of the lateral femoral condyle as shown by magnetic resonance imaging. The mechanism of injury has been described as due to bone compression during knee trauma. This may lead to compression of the lateral condylopatellar notch (sulcus). It has been suggested that detection of a deep notch on the plain lateral radiograph is a useful indirect sign of ACL tear. Depth of this notch was measured in 34 consecutive prospective patients assessed as having acute ACL tear clinically and proven at arthroscopy. In no patient was the notch deep, suggesting that this is not a useful sign in acute tears of the anterior cruciate ligament.