Effects of methoxyflurane anesthesia on the pharmacokinetics of 125I-IAZA in Sprague-Dawley rats

Effects of methoxyflurane anesthesia on the pharmacokinetics of intravenous 125I-IAZA in rats are reported. No significant differences in t(1/2alpha), t(1/2beta), V(SS), and ClTB for total radioactivity (125I-IAZA and metabolites) were observed between the anesthetized (Group 1, n = 4) and nonanesthetized (Group 2, n = 3) animals. For 125I-IAZA, ClTB increased from 646 +/- 52 mL/h/kg to 2250 +/- 351 mL/h/kg and t(1/2beta) decreased from 97.7 +/- 17.5 min to 35.6 +/- 5.4 min, for Groups 1 and 2, respectively. There were no differences in V(SS) or t(1/2alpha) between the two groups. These findings support literature reports of anesthetic effects on xenobiotic pharmacokinetics, and indicate a need for caution in the evaluation of preclinical imaging studies in which animals are immobilized with anesthetics.     

Y-appendicoplasty: a technique to minimize stomal complications in antegrade continence enema

PURPOSE: The antegrade continence enema (ACE) is an effective method of treatment of fecal incontinence and constipation. However, the original procedure described is not easy to perform and is associated with a high complication rate, especially stomal stenosis-necrosis (55%). Even with introduction of orthotopic appendicostomy, composite series still report an incidence of 30% with stomal problems. The authors report a virtually complication-free simple modification, the Y-appendicoplasty. METHODS: The base of the appendix is imbricated into cecum by 2 successive rows of interrupted seromuscular stitches. A small Y-shaped incision is made on the abdominal wall at McBurney's point, and 3 triangular skin flaps are raised. The appendix is brought out of the skin incision. The tip is excised, and 3 vertical cuts are made 120 degrees apart. The 3 appendiceal flaps thus created are interdigitated with the skin flaps using interrupted sutures. RESULTS: Twelve children underwent Y-appendicoplasty and orthotopic appendicostomy. Mean operating time was 1 hour. None experienced stomal complications that required intervention. Control of fecal continence with ACE ranged from excellent to good. CONCLUSION: Y-appendicoplasty and orthotopic appendicostomy minimizes complications for ACE and is easy to perform.     

Comparison of morbidity of lumbar flank approach and transperitoneal approach for radical nephrectomy

PURPOSE: This is a retrospective study comparing the clinical data and morbidity of transperitoneal radical nephrectomy (TRN) and simple nephrectomy. MATERIAL AND METHODS: From 1st January, 1989 to 1st January, 1996 a total of 90 simple nephrectomies and from 1st January, 1996 to 1st August, 1999 a number of 85 TRN were performed at the Department of Urology of the Saint Stephen Hospital. The analysis of clinical data included operative time, length of analgesics, postoperative hospital stay and blood loss, as well as morbidity. RESULTS: The mean operative time for TRN was 170 min., being 95 min. for simple nephrectomy. The mean blood loss for TRN was 250 ml, and 400 ml for simple nephrectomy. There were different types of morbidity for TRN and simple nephrectomy. The complications of TRN mean minimal risk and easy correctibility. CONCLUSION: Our results demonstrate an overall clear advantage of TRN when compared to simple nephrectomy.     

Prior topical anesthesia reduces time to full cycloplegia in Chinese

PURPOSE: To investigate the effect of prior anesthesia on the time to full cycloplegia in young Chinese subjects. METHODS: The amplitude of accommodation was monitored over a 50-minute interval after the application of 1% cyclopentolate hydrochloride with a pretreatment of 0.4% benoxinate (oxybuprocaine) or 0.9% saline solution (control). Using a nonlinear mathematical model, the rate of accommodative loss (k) and the time required for 95% of total cycloplegia (T95%) were determined. RESULTS: Statistical analysis revealed a significantly faster rate of accommodative loss (P < .0001) after prior anesthesia (0.129 +/- 0.05) compared with the controls (0.103 +/- 0.04). T95% was noted at 26.43 +/- 10.22 minutes after prior anesthesia, which was significantly shorter (P < .0001) than that after the saline treatment (35.28 +/- 16.51 minutes). CONCLUSIONS: Prior application of topical anesthetic can shorten the time to full cycloplegia for people, such as the Chinese, with dark irides.     

Effect of the aryl substituent on antitumor activity of 2-substituted-1,4-dihydroxy-9,10-anthraquinones and 2-substitutedanthracene-1,4,9,10-tetraones

2-(1-Aryl-1-hydroxymethyl)- and 2-aroyl-DHAQ derivatives (DHAQ, 1,4-dihydroxy-9,10-anthraquinone), and 2-(1-aryl-1-hydroxymethyl)-ATO derivatives (ATO, anthracene-1,4,9,10-tetraone) were synthesized and their antitumor activities were determined. 2-(1-Aryl-1-hydroxymethyl)-DHAQ derivatives showed a stronger cytotoxicity compared to the series of 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinone derivatives. It was suggested that the presence of aryl group at the side chain accelerated the bioreductive activation leading to cell death. 2-Aroyl-DHAQ derivatives, despite their higher electrophilicity, revealed smaller cytotoxicity and antitumor activity (expressed by T/C value) than 2-(1-aryl-1-hydroxymethyl)-DHAQ derivatives. Thus, no consistent relationship between the electronic effect on aromatic side chain and the cytotoxicity was observed. ATO series exhibited a higher antitumor activity (T/C, 125 to approximately 218%), though their cytotoxicity was not further improved compared to that of 2-(1-aryl-1-hydroxymethyl)-1,4-dihydroxy-9,10-anthraquinones. They manifested no correlation between the cytotoxicity and the antitumor activity. In case of 2-[1-hydroxy-1-(4-propylphenyl)-methyl]-ATO, the most bioactive one in vivo among the same series, it showed an ED50 value of 10.2 mg/mL and a T/C value of 218%. It is assumed that the anthracene-1,4,9,10-tetraones after uptake into cellular tissues might be transformed to a cytotoxic metabolite(s).     

Cochlear implantation

Cochlear implants are the single greatest advancement of the late 20th century for the deaf and hearing impaired. Recent expanding guidelines as well as surgical techniques are discussed. Cochlear implantation is currently the only means to restoring partial hearing to patients with severe-to-profound sensorineural loss not aidable with conventional amplification.     

Ninhydrin as a reversible protecting group of amino‐terminal cysteine

Abstract: The proximity of the α‐amine and β‐thiol of α‐amino terminal‐cysteine (NT‐Cys) residues in peptides imparts unique chemical properties that have been exploited for inter‐ and intra‐molecular ligation of unprotected peptides obtained through both synthetic and biological means. A reversible protecting group orthogonal to other protection strategies and reversible under mild conditions would be useful in simplifying the synthesis, cleavage, purification and handling of such NT‐Cys peptides. It could also be useful for the sequential ligation of peptides. To this end, we explored tri‐one chemistry and found that ninhydrin (indane‐1,2,3 trione) reacted readily with cysteine or an NT‐Cys‐containing peptide on‐ or off‐resin at pH 2–5 to form Ninhydrin‐protected Cys (Nin‐Cys) as a thiazolidine (Thz). The Thz ring, protecting both the amino and thiol groups in Nin‐Cys, completely avoids the formylation and Thz side reactions found during hydrofluoric acid (HF) cleavage when N‐π‐benzyloxymethyl histidine groups are present. Nin‐Cys is stable during coupling reactions and various cleavage conditions with trifluoroacetic acid or HF, but is deprotected under thiolytic or reducing conditions. These properties enable a facile one‐step deprotection and end‐to‐end‐cyclization reaction of Nin‐Cys peptides containing C‐terminal thioesters.     

Does circumcision alter the periurethral bacterial flora?

A prospective study of 25 boys who underwent circumcision for medical reason was performed. Specimens of periurethral bacterial flora were taken before operation as well as 3 weeks after surgery, so that each boy acted as his own control. Before circumcision, 13 (52%) harboured uropathogenic organisms (Escherichia coli and other coliforms, Enterococcus spp, Proteus spp, Pseudomonas spp, and Klebsiella spp); after circumcision, none of the boys had uropathogens, the only organisms cultured from the periurethral region being skin commensals. We postulate that circumcision converts a ‘cul-de-sac' that is a reservoir of organisms capable of causing ascending urinary tract infection into a surface colonised by natural skin organisms. This study provides circumstantial evidence supporting the idea that circumcision in well-selected patients may confer protection from urine infection. Accepted: 15 March 1997