Iontophoretically applied corticosteroids do not affect the firing of hippocampal neurons

In view of the possible role of the hippocampus in the neuroendocrine regulation of ACTH secretion, experiments were conducted in rats and cats in which cortisol (C) and corticosterone (CS) were applied by iontophoresis and pressure microinjection while recording from single identified pyramidal cells in the dorsal hippocampus, using multi-barrelled microelectrodes. None of the more than 500 cells tested responded with a significant change in firing rate. The possible relation of these findings to neuroendocrine regulation of ACTH secretion is discussed.     

Traumatic tricuspid regurgitation complicating endocarditis and right-to-left intracardiac shunt. A case report of successful operation

OBJECTIVE: To assess the prevalence of cystinuria and cystine stone disease among families of patients with cystine stones, and to determine their distribution by age, sex and associated morbidity. SUBJECTS AND METHODS: The study comprised 180 relatives (87 males and 93 females, mean age 43 years) descended from two brothers over four generations who live in two areas in northern Jordan. Data were collected using a questionnaire and home visits, by urinary cystine testing and radiology to detect stone, and assessing hypertension and renal impairment. RESULTS: Of the 180 subjects, 104 (58%) had a positive reaction for cystine in urine; 33 (32%) of these were younger than 15 years. Twenty members (11%) of the families had evidence of renal cystine stone disease. Hypertension and renal impairment were detected in a significant proportion of individuals with cystine stone disease. CONCLUSION: Cystinuria is a major risk factor for cystine stone formation. Family screening is valuable in detecting the cystinuric population and in assessing individuals with stones. Early recognition, treatment and counselling result in better management and prevention. The establishment of a cystine study group in our region is essential.     

Potentiometric sensor for methylene blue based on methylene blue-silicotungstate ion association and its pharmaceutical applications

A methylene blue (MB) poly(vinyl chloride) membrane sensor based on MB-silicotungstate (SLT) ion association as electroactive material was described. The linear response covered the range 1 x 10(-3)-1 x 10(-6) mol x dm(-3) MB solution, with a slope 52.0+/-0.8 mV decade(-1) (pH range 3.0-10.0). The detection limit was 7.65 x 10(-7) mol x dm(-3). The electrode showed stability, good reproducibility and fast response. Interferences from common inorganic cations, some organic base were negligible. These characteristics of the electrode enabled it to be used successfully for the determination of MB in injection. There was a good agreement for the results of MB content in injection between potentiometric method and USP standard procedure.     

Software transactional memory

Summary.  As we learn from the literature, flexibility in choosing synchronization operations greatly simplifies the task of designing highly concurrent programs. Unfortunately, existing hardware is inflexible and is at best on the level of a Load–Linked/Store–Conditional operation on a single word. Building on the hardware based transactional synchronization methodology of Herlihy and Moss, we offer software transactional memory (STM), a novel software method for supporting flexible transactional programming of synchronization operations. STM is non-blocking, and can be implemented on existing machines using only a Load–Linked/Store–Conditional operation. We use STM to provide a general highly concurrent method for translating sequential object implementations to non-blocking ones based on implementing a k-word compare&swap STM-transaction. Empirical evidence collected on simulated multiprocessor architectures shows that our method always outperforms the non-blocking translation methods in the style of Barnes, and outperforms Herlihy’s translation method for sufficiently large numbers of processors. The key to the efficiency of our software-transactional approach is that unlike Barnes style methods, it is not based on a costly “recursive helping” policy. Received: January 1996 / Revised: June 1996 / Accepted: August 1996