Glycoproteins present in human follicular fluid that inhibit the zona- binding capacity of spermatozoa

Previous studies have suggested that human follicular fluid contains factors that reduce the zona-binding capacity of spermatozoa. The present study provides further evidence of the existence of such factors. Using the hemizona binding assay (HZA), we have shown that the inhibitory effect of human follicular fluid on the zona-binding capacity of spermatozoa is concentration-dependent, an inhibitory effect being detected when the concentration of human follicular fluid was > or = 10%. A 1% concentration of human follicular fluid did not possess this inhibitory activity. Heating human follicular fluid at 56 degrees C for 30 min did not affect its inhibitory properties; treatment with proteinase-K abolished such inhibition. Human follicular fluid was fractionated sequentially by concanavalin-A affinity chromatography, Mono Q ion-exchange chromatography and Superose-12 gel filtration. The zona binding inhibitory activity resided in the fraction which bound to the lectin and Mono Q column and contained molecules with native molecular weights of 32 and 192 kDa. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis suggested that the 192 kDa glycoprotein was a tetramer, while the 32 kDa glycoprotein remained as a single molecular species under denaturing conditions. We conclude that two glycoproteins were responsible for the zona binding inhibitory activity of human follicular fluid. The physiological role of these factors remains unclear.      

Diagnosis of adrenal cortical dysfunction by liquid chromatography-tandem mass spectrometry

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to measure 6 metabolic compounds of the adrenocorticosteroid pathway simultaneously on residual specimens from patients who had previously been previously diagnosed, on the basis of immunoassays, as having congenital adrenal hyperplasia (CAH), 11 beta-hydroxylase deficiency, 21-hydroxylase deficiency, or Addison disease (adrenal insufficiency). Two subjects with normal adrenal function had serum cortisol values of 13.6 and 8.9 micrograms/dL and serum cortisone values of 2.1 and 0.6 microgram/dL, but the rest of the compounds were undetectable. Two patients with 11 beta-hydroxylase deficiency had serum 11 beta-deoxycortisol values of 14.9 and 10.0 micrograms/dL and serum 11-deoxycorticosterone values of 3.9 and 1.0 microgram/dL, but their serum levels of cortisol and cortisone were diminished. A patient with 21-hydroxylase deficiency had a highly increased serum 17-hydroxyprogesterone concentration of 28.5 micrograms/dL (or 28,500 ng/dL, the traditional unit to report this assay) and a serum 21-deoxycortisol concentration of 6.9 ug/dL (this is a pathologic marker of 21-hydroxylase deficiency that is nondetectable in sera of healthy subjects). This patient also had diminished concentrations of serum cortisol and cortisone (0.9 and 0.3 microgram/dL, respectively). At 30 and 60 min after corticotropin (ACTH) stimulation, serum cortisol was the only compound that showed a dramatic increase in the normal subjects; the patient with 21-hydroxylase deficiency showed an increase of serum 17-hydroxyprogesterone level, but no increase of serum cortisol level; the patient with Addison disease showed no increase in the levels of serum cortisol or other compounds. Metyprapone, which blocks 11 beta-hydroxylase activity, increased the serum 11-deoxycorticosteroid levels and decreased the serum cortisol level. This pilot study demonstrates that it is feasible to use LC-MS/MS for the laboratory diagnosis of adrenal cortical dysfunction. The authors envision that LC-MS/MS may soon become an ideal analytical technique for the diagnosis of such endocrine diseases.     

A survey of bacterial diversity in ticks,lice and fleas from Australia

We isolated bacteria from ticks, lice and fleas. Partial small subunit rRNA sequences were obtained for each isolate and the closest matches in the FastA database were determined. These bacteria were mostly Gram-positive (Firmicutes), although representatives from the Proteobacteria (alpha, beta, gamma subdivisions) and CFB group were also isolated. Most of the isolates we found were from genera that were present in most of the ectoparasites studied, but a few genera were restricted to one species of ectoparasite. The most commonly isolated genera were Stenotrophomonas, Staphylococcus, Pseudomonas, Acinetobacter and Bacillus. Species of Bacillus and Proteus, which have biopesticide potential, were found in some of these ectoparasites. Overall, the communities of bacteria were similar to those found in other studies of parasitic arthropods.     

Overwhelmingly asynchronous firing of rat subthalamic nucleus neurones in brain slices provides little evidence for intrinsic interconnectivity

In Parkinson's disease the neurones of the subthalamic nucleus show increased synchrony and oscillatory burst discharge, thought to reflect a breakdown of parallel processing in basal ganglia circuitry. To understand better the mechanisms underlying this transition, we sought to mimic this change in firing pattern within sagittal slices of rat midbrain. The firing patterns of up to four simultaneously extracellularly recorded subthalamic nucleus (STN) neurones were analysed using burst and oscillation detection programs, and correlated activity between pairs of neurones assessed. In control conditions all but 11 of 488 (2%) neurones fired in a predominantly tonic pattern (with mean oscillation frequency >3 Hz), with no significantly cross-correlated activity in any of 393 pairs of neurones. The glutamate antagonists DL-2-amino-phosphonopentanoic acid (APV), 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 6-methyl-2-(phenylethynyl)pyridine (MPEP) did not change the firing rate or pattern of these cells, providing no evidence for a role of glutamatergic collaterals within the STN under these conditions. The GABA(A) receptor antagonist bicuculline and GABA(B) receptor antagonist (2S)-3-[[(1S)-1-(3,4-dichlorophenyl)ethyl]amino-2-hydroxypropyl]phenylmethyl phosphinic acid (CGP 55845) were also without effect on firing rate or pattern in these cells, suggesting that there was no active input from other GABAergic basal ganglia nuclei in this slice. The dopamine receptor antagonist haloperidol caused no significant change to firing rate or pattern of firing in these cells, suggesting that there was no active dopaminergic input in this slice. Excitations of STN neurones by muscarine, (+)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (ACPD), N-methyl-D-aspartic acid (NMDA) or dopamine were all unaccompanied by a change in firing pattern or any significant correlated activity between STN neurone pairs. Burst firing could be induced in STN neurones with either the potassium channel blocker tetraethylammonium (TEA; 10 mM; in 100/138 [72%] of cells) or with a combination of NMDA and the calcium-activated potassium channel blocker apamin (in 101/216 [47%] of cells). Burst firing in TEA was unchanged by CNOX and APV, MPEP, CGP55845, haloperidol, dopamine, and ACPD, although muscarine produced a significant increase in oscillation frequency. Burst firing in NMDA and apamin was unchanged by CNQX and APV, dopamine, muscarine and ACPD, although bicuculline caused a significant increase in oscillation frequency. Such burst firing was not accompanied by synchrony in any condition, either alone, or during application of excitatory agents or glutamate or GABA antagonists. As the bursting seen here was unaccompanied by the synchronous activity that has often been observed (pathologically) in vivo, it probably reflects solely intrinsic STN neuronal properties, rather than network activity. No functional role was found for glutamatergic collaterals within the STN, either when cells are firing tonically or burst firing. The circuitry needed to produce synchrony in the STN is most likely not intrinsic to the STN itself, but requires connections with other basal ganglia nuclei, and/or the cortex, which are not present in this preparation.     

Testing a policy for skull radiography (and admission) following mild head injury

There has been, and continues to be, conflicting advice regarding skull radiography following an apparently uncomplicated head injury. Policies on admission are often ill defined. In 1983, representatives of the Royal College of Radiologists met neurosurgeons at a seminar in Harrogate organized by the DHSS and laid down clear, but little publicized, joint recommendations: "The Harrogate Criteria". The survey described here evaluated an existing liberal policy for skull radiography (and a loose policy for admissions) against these recommendations, and it was concluded that the number of patients having skull radiography (74% of head injury attenders) was excessive. Measured against the "Harrogate Criteria", requests for 36% of the adult and 47% of children's skull radiographs did not fulfil these criteria. As a corollary, it was also concluded that loose admissions policies could usefully be altered to comply more closely with the Harrogate recommendations. This would not necessarily reduce the numbers admitted, but would provide casualty officers with a framework on which to base this crucial aspect of clinical decision making, where presently there is often very little structure at all. The authors suggest that all the options have not been fully explored, and that a simple but important alteration to the Harrogate guidelines would provide an even closer link between policy on skull radiography and patient admission. Specifically, most patients who are to be admitted do not need skull radiographs.     

"Diaphragm-like" strictures of the small bowel in patients treated with non-steroidal anti-inflammatory drugs

The radiological findings are described in four patients who developed strictures of the small bowel, and who had received non-steroidal, anti-inflammatory drugs (NSAIDs) for 1.5-15 years. Clinical presentation was that of subacute small bowel obstruction. Small bowel barium studies showed multiple discrete strictures. Some strictures were indistinguishable from those of regional enteritis. Others however were narrow "diaphragm-like" septae encroaching on and markedly narrowing the ileal lumen, and shown histologically to be due to submucosal fibrosis. It is suggested that these strictures are likely to be consequent on NSAIDs administration and that radiologists and surgeons need to be aware of these "diaphragms" which can be very difficult to detect on barium examination, either small bowel follow-through or enteroclysis, and at laparotomy.