Unilateral epidermal naevus resembling acanthosis nigricans

A man born with a unilateral epidermal naevus on the right side of the abdomen developed at puberty symmetrical benign acanthosis nigricans in the body folds. The symmetrical eruption later disappeared completely. The unilateral epidermal naevus and the symmetrical eruption showed identical histological features, i.e. those of acanthosis nigricans. At the age of 32 he developed a muco-epidermoid cancer of the left parotid gland. A decision whether the association of unilateral epidermal naevi with malignant tumours occurs with unusual frequency requires (a) a long follow-up of the patient with the unilateral naevus, (b) a differentiation of the unilateral eruption from unilateral malignant acanthosis nigricans and (c) statistical evidence.     

A heterologous system for detecting eukaryotic enzymes which synthesize pseudouridine in transfer ribonucleic acids

tRNA pseudouridylation activities have been detected in embryonic mouse cell fractions and in extracts from HeLa, mouse L-cell and baby hamster kidney (BHK) cell lines. These activities were identified by the use of heterologous reaction systems, with tRNA from hisT strains of Salmonella typhimurium as substrate. hisT mutants are defective for an enzyme that forms psi residues in the anticodon region of many tRNAs and accumulate undermodified species of tRNA. The pseudouridylation activity from BHK cells has been examined in detail and quantitated by a modified tritium release assay (Cortese, R., Kammen, H.O., Spengler, S.J., and Ames, B.N. (1974) J. Biol. Chem. 249, 1103-1108). Maximal rates of tritium release required a suitable cationic environment (optimally, a combination of Mg2+ and NH4+) and a thiol reductant. The activity was totally inhibited in the presence of thiol-reactive reagents, such as 5,5'-dithiobis(2-nitrobenzoic acid) and p-chloromercuribenzoate. A major portion of this 3H release activity was associated with psi modification reactions. This conclusion stems from the following observations: (a) BHK extracts preferentially catalyzed a release of 3H from hisT [5-3H]tRNA, rather than from similarly labeled wild type tRNA; (b) this activity was specific for protons attached to C5 of the pyrimidine rings; no release of 3H was obtained with hisT or wild type [6-3H]tRNA as substrate; (c) the reaction products of hisT tRNA with BHK enzyme were examined by reverse phase column chromatography of tRNAPhe isoacceptors on RPC-5 columns. The enzyme modified both of the principal isoacceptors of hisT tRNAPhe to an equal extent, yielding products indistinguishable from wild type tRNAPhe. Significant levels of 3H release were obtained by the action of enzyme on wild type [5-3H]tRNA, even after gel filtration of the enzyme. This suggests that the enzyme may be able to hypermodify certain species of wild type S. typhimurium tRNA. The activities for wild type tRNA and hisT tRNA appeared to be associated with the same enzyme.     

Evidence for active and passive urate transport in the rat proximal tubule

Studies utilizing the technique of simultaneous microperfusion of peritubular capillaries and tubular lumen of the proximal tubule of the rat were performed to determine if the absorption of urate was an active transport process and to determine the passive permeability coefficient for urate. When radioactive urate of equal specific activity and concentration was present in both perfusion solutions, the ratio of collected to initial concentrations of urate in the luminal perfusate (CO/CI) was 0.71 +/- 0.02. This gradient was higher than that predicted at equilibrium from the electrical potential difference determined in the in vitro perfused rabbit proximal tubule. The addition of para-chloromercuribenzoate (PCMB) to both solutions resulted in a significantly higher CO/CI of 0.90 +/- 0.02. This latter value is closer to the value predicted at electrochemical equilibrium. In separate studies, the unidirectional fluxes of urate were determined in the presence of PCMB. The calculated passive permeability coefficient averaged approximately 0.94 pmol . min-1 . mm-1 . mM-1 and was equal in both directions. These results indicate that in the rat proximal tubule urate absorption is an active transport process. In addition, there exists a passive permeation pathway for urate movement out of and into the proximal tubule.     

Causes of ear trauma in Kenyan patients

Ear trauma is one of the most important epidemiological factors in causation of deafness. The causation of otologic trauma in eighty three patients is analysed. The triad of pain, hearing loss and tinnitus comprised the most frequent presenting complaints. Physical assault was the most common causation in 49.4% of the cases, road traffic accidents in 19.3% and self-inflicted injury in 15.6%. Law enforcement agencies constituted the most prominent factor in assault cases. Iatrogenic trauma was confined to 13.3% who were all below ten years of age. Road traffic accidents and violence from law enforcers were significant contributors to severe otologic damage as defined by dead ears and cerebrospinal otorrhoea.     

The three isoforms of transforming growth factor-beta co-stimulate rat T cells and inhibit lymphocyte apoptosis

We examined the therapeutic effect of cefluprenam (CFLP) on the polymicrobial urinary tract infection associated with infectious stones as compared to that of ceftazidime (CAZ), using the experimental polymicrobial urinary tract infection caused by Proteus mirabilis (P. mirabilis), Pseudomonas aeruginosa (P. aeruginosa) and Enterococcus faecalis (E. faecalis). In order to form bladder stones in rats, a sterile zinc ring was implanted as a foreign body, followed by inoculating P. mirabilis E05106 transurethrelly. Thereafter, P. aeruginosa E030033 and E. faecalis 966 were inoculated according to the same way. CFLP or CAZ was administered intravenously twice a day for 5 days. The therapeutic effect was evaluated by the eradication of these bacteria from the urine, the kidney and stones, inhibition of growth of stones, and also a value of BUN. The urinary excretion rates of CFLP and CAZ was also determined (20 mg/kg). In result, CFLP significantly more effective in the eradication of P. mirabilitis, P. aeruginosa and E. faecalis from the urine, the kidney and stones than the control than the control (p < 0.05). Furthermore, CFLP significantly more effective in the eradication of P. aeruginosa from the urine and also E. facalis from the urine and stones (p < 0.05). Meanwhile, CAZ significantly more effective in the eradication of P. mirabilis from the urine, the kidney and stones and also P. aeraginosa from the kidney and stones than the control. However, CAZ did not show eradicative effect on E. faecalis. The urinary excretion rates of CFLP and CAZ at rats were 59.3% and 59.4%, respectively, within 8 hrs after administration, showing a similar excretion pattern. CFLP exhibited the prominent therapeutic effect on polymicrobial urinary tract infection associated with infectious stones caused by P. mirabilis, P. aeruginosa and E. faecalls. On the basis of these results, it has been strongly suggested that CFLP is highly beneficial in the management of intractable polymicrobial urinary tract infectious in clinic.