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.

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.

Case report: renal excretion of gastrografin following rectal administration

Renal excretion of water soluble iodinated contrast media following oral administration has often been described but no reports describing renal excretion following rectal administration of such contrast have previously been described. We describe a case of renal excretion of diatrizoate methylglucamine (Gastrografin, Schering) following a diagnostic 'gastrografin enema' in a woman with caecal carcinoma.

Allogeneic bone-marrow transplantation without protective isolation in adults with malignant disease

Bone-marrow transplant (BMT) patients are severely immunocompromised immediately after the procedure and they are commonly nursed in strict protective isolation to reduce the risk of both infection and graft-versus-host disease (GvHD). We have studied a consecutive series of patients to see whether protective isolation is of benefit as prophylaxis against infectious complications of BMT. 50 consecutive patients who had malignant disease and received their first BMT from siblings or unrelated donors were nursed in standard single rooms with visitors instructed to wash their hands. A subset of 20 patients living locally spent a median of 25 days in hospital after BMT; they also spent some time at home on a median of 8 days before engraftment and 3 patients went home on more than 90% of their hospital days. 16 patients (32%) had positive bacterial cultures and/or focal infection. Gram-positive bacteraemia was found in 12 subjects (24%) but there were no gram-negative or deep fungal infections. Grade II or III acute GvHD developed in 17 patients (34%). There were no deaths from infection or acute GvHD. Transplant-related mortality was 6% in the first 100 days and 18% overall with a median follow-up of 22 months. Our mortality data compare favourably with those from institutions with strict isolation procedures. We conclude that BMT may be safely completed in some institutions without either protective isolation or the need to confine patients continuously in hospital.