Correlation between gamma-aminobutyric acidA receptor ligand-induced changes in t-butylbicyclophosphoro[35S]thionate binding and 36Cl- uptake in rat cerebrocortical membranes.

We have explored the functional significance of various drug-induced changes in t-[35S]butylbycyclophosporothionate (TBPS) binding to gamma-aminobutyric acidA (GABAA) receptors by comparing them with the actions of the drugs on GABA-induced 36Cl- uptake in rat cerebrocortical membrane preparations. In the presence of micromolar concentrations of GABA, various benzodiazepine receptor agonists, 3 alpha-21-dihydroxy-5 alpha-pregnan-20-one, and pentobarbital inhibited [35S]TBPS binding, whereas ethyl-beta-carboline-3carboxylate (beta-CCE), an inverse agonist, stimulated it, in general agreement with earlier reports [Mol. Pharmacol. 23:326-336 (1983); Mol. Pharmacol. 30:218-225 (1986)]. The drug-induced changes in [35S]TBPS binding, after normalization with respect to the corresponding action of diazepam, were closely related to the relative ability of the drugs to affect 36Cl- uptake, with a correlation coefficient of 0.98 and a slope of 0.85. Upon abolishment of GABA action by the use of bicuculline, however, all the tested drugs stimulated [35S]TBPS binding to various degrees, and their relative changes displayed a lower correlation coefficient of 0.69, with a slope of 2. In particular, the effects of the anesthetic steroid and pentobarbital on [35S]TBPS binding were markedly altered by GABA, which at 2 microM increased not only their maximal effects, but also their half-maximal concentrations severalfold. On the other hand, GABA did not significantly affect these parameters for diazepam under our experimental conditions. Also, the GABA-independent changes in [35S]TBPS binding produced by various benzodiazepine receptor agonists matched reasonably well the actions of the drugs on 36Cl- uptake, with a correlation coefficient of 0.85 and a slope of 1.0. These data suggest more pronounced functional coupling of the GABA sites with those for the steroid and the barbiturate, as compared with the benzodiazepine site. It appears that the degree of [35S]TBPS binding in the presence of GABA closely reflects the functional state of GABAA receptors and may be useful for characterization of allosteric interactions between various sites on the receptors.     

The high-frequency/acceleration head heave test in detecting otolith diseases.

OBJECTIVE: To investigate whether transient, high-acceleration interaural head heaves (translational vestibulo-ocular reflex [tVOR]) could aid in the diagnosis of otolith diseases. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary referral center. PATIENTS: Thirteen patients with symptoms suggestive of otolith diseases and 10 age-matched controls. INTERVENTIONS: Patients underwent a clinical otoneurologic examination and standard laboratory audiovestibular evaluation, including audiometry, electronystagmography with bithermal caloric, Halmagyi-Curthoys head thrust test with search coils, and vestibular-evoked myogenic potential. All subjects underwent subjective visual vertical (SVV) and tVOR testings. MAIN OUTCOME MEASURES: Sensitivity (ratio of peak eye to peak head velocities) and velocity gain (ratio of actual to ideal peak eye velocities). RESULTS: Five of 13 patients showed no abnormality in any tests. Of the remaining 8, 3 (38%) had reduced tVOR responses, whereas 1 (13%) had abnormal SVV. Sensitivity and velocity gains were symmetrically reduced in 2 patients, who had symptoms for 8 and 24 months. A third patient, symptomatic for 7 weeks, had asymmetric reduction of tVOR responses and a deviated SVV. CONCLUSION: Both head heave and SVV tests detect acute, asymmetric otolith diseases. Subjective visual vertical test relies on imbalance of utricular tone and may not detect bilateral symmetric diseases or partial diseases with central compensation. Our preliminary data in a small group of patients show that measuring the tVOR in a higher and more physiologic range of frequencies may serve as useful adjunct to detect acute and chronic otolith dysfunction and seems to be superior to the SVV in detecting bilateral symmetric or asymmetric otolith diseases.     

Size differences between human X and Y spermatozoa and prefertilization diagnosis

Normal human spermatozoa carry either the X or the Y chromosome. The differences between X and Y spermatozoa (X and Y haploid cells) may exist in two areas: the different chromosomes (i.e. different kinds and numbers of genes) and the different sperm structures and functions (i.e. different genetic expression). The aim of this study was to determine whether there are any size between X and Y spermatozoa and whether sperm size and shape varies between men. Identification of the Y (and X inferred) status of individual spermatozoa was carried out by polymerase chain reaction (PCR), amplifying the putative testis- determining gene (SRY) together with a control gene (ZP3). PCR amplification of 871 out of 895 (97.3%) single motile spermatozoa showed that 444 (51.0%) were Y and 427 (49.0%) were X-bearing spermatozoa. Of 233 normally-shaped but immobilized spermatozoa, 217 (93.1%) were photographed and measured. Statistically, the length, perimeter and area of the sperm heads, and the length of the sperm necks and tails of X-bearing spermatozoa were significantly larger and longer than those of Y-bearing spermatozoa. Some peculiarities (or variations) in the X and Y sperm shape and size in individual donors were found. The pre-screening by micro-measurement of these specific haploid characteristics of individual spermatozoa in different donors, which may be closely related to their different genetic conditions (or diseases), may be important in human medicine and animal husbandry, especially in sperm prefertilization diagnosis.      

Community acquired fulminant Pseudomonas infection of the gastrointestinal tract in previously healthy infants

Three previously healthy infants presented with diarrhoea and pyrexia and deteriorated rapidly. Two patients had necrotizing bowel disease requiring aggressive surgical intervention. All survived. P. aeruginosa gastrointestinal infection in previously healthy children is an extremely rare condition with a high mortality. Ecthyma gangrenosum was present in over 60% of reported cases although often not recognized initially. A high index of clinical suspicion, including prompt recognition of ecthyma gangrenosum, is mandatory for an early diagnosis of P. aeruginosa gastrointestinal infection. Early diagnosis and treatment may improve the prognosis.     

Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound,CT and MR appearance

The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. The previous literature is also reviewed.     

Geographic variations and temporal trends of Salmonella -associated hospitalization in the U.S. elderly, 1991-2004: A time series analysis of the impact of HACCP regulation

Background  

About 1.4 million Salmonella infections, a common food-borne illness, occur in the U.S. annually; the elderly (aged 65 or above) are most susceptible. In 1997, the USDA introduced the Pathogen Reduction and Hazard Analysis and Critical Control Points Systems (PR/HACCP) which demands regular Salmonella testing in various establishments processing meat products, such as broiler chickens. Impact evaluations of PR/HACCP on hospitalizations related to Salmonella are lacking.