Metabolic, molecular genetic and toxicological aspects of the acetylation polymorphism in inbred mice.

Over the past 10 years, much fascinating information has been obtained concerning the biochemistry, genetics, toxicological implications and molecular genetics of the N-acetylation polymorphism in mice. Using C57BL/6J (B6) mice as representative of rapid acetylation and A/J (A) mice as representing slow acetylation, it has been shown that the polymorphism observed in N-acetyltransferase (NAT) activity in liver also occurs in kidney, bladder, blood, and other tissues. The development of congenic acetylator mouse lines derived from B6 and A, have provided the necessary tools to study the role of the acetylation polymorphism, on either the B6 or A genetic background, free of nearly all other genetic differences between these strains. Eliminating genes which modify and complicate the differences due to the acetylator genes make the congenic lines very useful in toxicology studies, particularly those involving carcinogenesis. The molecular genetic basis of the acetylator polymorphism in B6 and A mice involves two Nat genes. Nat-1 encodes a protein termed NAT1 which is identical in rapid and slow acetylator strains. Nat-2, however, differs between rapid and slow strains by a single nucleotide change in the coding region. The corresponding NAT2 proteins differ by a single change at amino acid 99: an hydrophilic asparagine in rapid acetylator NAT2 to an hydrophobic isoleucine in NAT2 from slow acetylators. The mechanistic basis for the differences between rapid and slow acetylation in mice appears to be that NAT2 from the rapid B6 strain is 15-fold more stable at 37 degrees C and is transcribed/translated with a maximal efficiency twice that of the enzyme from slow acetylator A mice. Results discussed in this review indicate that mice provide an excellent system for studying the N-acetyltransferase polymorphism and also are useful for modelling several aspects of the human N-acetyltransferase polymorphism.     

Ciprofloxacin concentration in the rabbit aqueous humor and vitreous following intravenous and subconjunctival administration

Summary 12 mg (6 ml) ciprofloxacin were intravenously administered to rabbits. Using high-pressure-liquid-chromatography the concentration in serum, aqueous humor and vitreous were measured after 1, 4, 10 and 24 h. The mean serum levels were 0.698 mg/l and 0.0425 mg/l after 1 and 10 h, respectively. The drug reached mean levels in the aqueous humor of 0.0595 mg/l and 0.0073 mg/l, respectively. Concerning the subconjunctival application 1 mg (0.5 ml) ciprofloxacin was injected either epibulbar near the limbus corneae or under the conjunctiva of the lower fornix. The mean aqueous humor levels were 0.887 mg/l and 0.094 mg/l after 1 and 10 h, respectively, following epibulbar injection. In contrast, the fornix-injection produced mean levels of 0.0267 mg/l and 0.025 mg/l in the aqueous humor after 1 and 10 h, respectively. The concentration of ciprofloxacin in the vitreous was near the detection limit following every method of administration of the drug. The importance of differentiating between epibulbar subconjunctival application and the injection under the conjunctiva of the fornix is discussed.

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Ciprofloxacin-Konzentration im Kammerwasser und Glaskörper des Kaninchens nach intravenöser und subkonjunktivaler Gabe

Zusammenfassung Kaninchen wurden 12 mg (6 ml) Ciprofloxacin intravenös appliziert und die Konzentration nach einer, 4, 10 und 24 h im Serum, Kammerwasser sowie Glaskörper mittels HPLC bestimmt. Die Mittelwerte betrugen im Serum 0,698 mg/l nach 1 h und 0,0425 mg/l nach 10 h sowie im Kammerwasser 0,0595 mg/l bzw. 0,0073 mg/l. Bei der subkonjunktivalen Gabe wurde 1 mg (0,5 ml) entweder epibulbär am Limbus corneae oder unter die Konjunktiva des unteren Fornix injiziert. Die Mittelwerte im Kammerwasser betrugen nach 1 h 0,887 mg/l und nach 10 h 0,094 mg/l nach epibulbärer Injektion, während die entsprechenden Werte nach Fornix-Applikation 0,0267 mg/l bzw. 0,025 mg/l betrugen. Im Glaskörper fanden sich bei allen Applikationsformen nur Werte im Bereich der Nachweisgrenze. Bei der subkonjunktivalen Injektion sollte differenziert werden zwischen der Gabe am Limbus corneae und der Applikation unter die Bindehaut im Fornix.

     

Metastatic adamantinoma diagnosed by fine-needle aspiration biopsy of the lung

We report two cases of metastatic adamantinoma to the lung diagnosed by FNAB. The cytologic appearance of the smears of each case was homogenous, containing small round and spindle cells with indistinct cytoplasm. The nuclei had delicate nuclear membranes, with finely dispersed chromatin and occasional micronucleoli. No pleomorphism was noted. Immunocytochemistry exhibited positive staining for keratin and vimentin. EM examination revealed numerous tonofilaments and well formed desmosomes. The cytologic diagnosis of metastatic adamantinoma can be made with the knowledge of a previous history of adamantinoma of bone, the comparison of the metastatic tumor with the original bone tumor, and the awareness of the long latency of the metastases. Immunocytochemistry and EM are needed to substantiate the diagnosis. © 1994 Wiley-Liss, Inc.     

Embryo transfer under ultrasound guidance improves pregnancy rates after in-vitro fertilization

Between October 1998 and January 1999, we examined the influence of ultrasound guidance in embryo transfer on pregnancy rate in 362 patients from our in-vitro fertilization (IVF)-embryo transfer programme. These patients were prospectively randomized into two groups: 182 had ultrasound-guided embryo replacement, and 180 had clinical touch embryo transfer. There were no statistically significant differences between the two groups with respect to age, cause of infertility and in the characteristics of the IVF cycle. The pregnancy rate was significantly higher among the ultrasound-guided embryo transfer group (50%) compared with the clinical touch group (33.7%) (P < 0.002). Furthermore, there was also a significant increase in the implantation rate: 25.3% in the ultrasound group compared with 18.1% in the clinical touch group (P < 0.05). In conclusion, ultrasound assistance in embryo transfer significantly improved pregnancy and implantation rates in IVF.     

The polymorphism of HLA-DR3 in South African populations

The polymorphism of HLA-DR3 was investigated in families and unrelated individuals of three population groups: South African (SA) Negroes, Cape Coloureds and SA Caucasoids. Serological and restriction fragment length polymorphism (RFLP) analysis indicated that DR3 could be subdivided into DRw17 (previously DR3.1) and DRw18 (previously DR3.2). In contrast, the two-dimensional (2-D) gel electrophoresis patterns could not distinguish between the DRB1 gene products of the HLA-DRw17 and DRw18 cells. Two DRB3 variants, correlating with the T-cell defined specificities Dw24 and Dw25 were identified at the genomic and product level. Of ten haplotypes studied with the newly defined HLA-DRw18 specificity, all had the DRB3 RFLP pattern associated with Dw24. HLA-DRw17 was found in all three population groups tested, although in the SA Negroes HLA-DRw18 was the prevalent DR3 subgroup. This subgroup was also present in the Cape Coloureds but was absent in the SA Caucasoid tested. HLA-DRw18 forms part of the most characteristic SA Negro haplotype, Bw42, DQw4, Dw“RSH,” while HLA-DRw17 is part of the classic Caucasoid haplotype, B8, DQw2, Dw3.     

Phase I trial of weekly paclitaxel and BMS-214662 in patients with advanced solid tumors.

PURPOSE: To assess the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacodynamics, and antitumor activity of continuous weekly-administered paclitaxel and BMS-214662, a novel farnesyl transferase inhibitor. EXPERIMENTAL DESIGN: Patients were treated every week as tolerated with i.v. paclitaxel (fixed dose, 80 mg/m(2)/wk) administered over 1 h followed by i.v. BMS-214662 (escalating doses, 80-245 mg/m(2)/wk) over 1 h starting 30 min after completion of paclitaxel. RESULTS: Twenty-six patients received 94 courses (one course, 21 days) of study treatment. Two patients received five courses of BMS-214662 as a weekly 24-h infusion (209 mg/m(2)/wk). The most common toxicities were grade 1 to 2 nausea/vomiting and/or diarrhea. DLTs observed at or near the MTD (200 mg/m(2)/wk) were grade 4 febrile neutropenia with sepsis occurring on day 2 of course 1 (245 mg/m(2)/wk), reversible grade 3 to 4 serum transaminase increases on day 2, and grade 3 diarrhea (200 and 245 mg/m(2)/wk). Objective partial responses were observed in patients with pretreated head and neck, ovarian, and hormone-refractory prostate carcinomas, and leiomyosarcoma. The observed pharmacokinetics of paclitaxel and BMS-214662 imply no interaction between the two. Significant inhibition (>80%) of farnesyl transferase activity in peripheral mononuclear cells was observed at the end of BMS-214662 infusion. CONCLUSIONS: Pretreated patients with advanced malignancies can tolerate weekly paclitaxel and BMS-214662 at doses that achieve objective clinical benefit. Due to multiple DLTs occurring at the expanded MTD, the recommended phase 2 dose and schedule is paclitaxel (80 mg/m(2) over 1 h) and BMS-214662 (160 mg/m(2) over 1 h) administered weekly.     

Dietary Fibre and Organic Acids in Kiwifruit Suppress Glycaemic Response Equally by Delaying Absorption—A Randomised Crossover Human Trial with Parallel Analysis of 13C-Acetate Uptake

Non-sugar components of kiwifruit reduce the amplitude of the glycaemic response to co-consumed cereal starch. We determined the relative contribution of different non-sugar kiwifruit components to this anti-glycaemic effect. Healthy participants (n = 9) ingested equal carbohydrate meals containing 20 g starch as wheat biscuit (WB, 30 g), and the sugar equivalent of two kiwifruit (KFsug, 20.4 g), either intrinsic or added as glucose, fructose and sucrose (2:2:1). The meals were WB+KFsug (control, no non-sugar kiwifruit components), WB + whole kiwifruit pulp (WB+KF), WB + neutralised kiwifruit pulp (WB+KFneut), WB + low-fibre kiwifruit juice (WB+KFjuice) and WB+KFsug + kiwifruit organic acids (WB+KFsug+OA). All meals were spiked with 100 mg sodium [1-¹³C] acetate to measure intestinal absorption. Each participant ingested all meals in random order. Blood glucose and breath ¹³CO₂ were measured at ingestion and at 15 min intervals up to 180 min. Compared with WB+KFsug, whole kiwifruit pulp (WB+KF) almost halved glycaemic response amplitude (p < 0.001), reduced incremental area under the blood glucose response curve (iAUC) at 30 min (peak) by 50% (p < 0.001), and averted late postprandial hypoglycaemia. All other treatments suppressed response amplitude half as much as whole kiwifruit and averted acute hypoglycaemia, with little effect on iAUC. Effects on ¹³CO₂ exhalation paralleled effects on blood glucose (R² = 0.97). Dietary fibre and organic acids contributed equally to the anti-glycaemic effect of kiwifruit by reducing intestinal absorption rate. Kiwifruit flesh effectively attenuates glycaemic response in carbohydrate exchange, as it contains fructose, dietary fibre and organic acids.     

Success of targeted transperineal biopsy in patients on surveillance for grade group 1 prostate cancer

IntroductionWe aimed to determine the minimum cross-sectional ellipsoid area on magnetic resonance (MR) of intraprostatic nodules that best predicts for subsequent targeted biopsies revealing ≥ grade group (GG) 2 disease.MethodsForty-six patients previously diagnosed with GG 1 prostate adenocarcinoma who received cognitively fused, MR-guided, transperineal targeted biopsies in addition to six random biopsies were included in this analysis. A Youden cutpoint analysis was used to determine the ellipsoid area in the axial plane best predicting for ≥GG 2 disease within the targeted biopsy cores and logistic regression used to assess the result.ResultsMedian time from MR imaging to targeted biopsy was 2.4 (1.4–5.5) months. Forty of 46 (87%) patients had one nodule and 6/46 (13%) had two separate nodules on MR that received targeted biopsy. Of the 52 nodules, five (10%), 33 (63%), and 14 (27%) were Prostate Imaging-Reporting and Data System (PI-RADS) 3, 4, and 5, respectively. Thirteen (25%), six (12%), and 33 (64%) were in the anterior, medial, and posterior regions of the prostate, respectively. Median area was 0.72 (0.49–1.29) cm² (average diameter 9.5 mm). Fifteen of 46 (33%) patients had ≥1 random biopsy and 20/52 (38%) nodules had ≥1 targeted biopsy revealing ≥GG 2 disease. The optimal area cutpoint was ≥0.7 cm², with an area under the curve of 0.671 (0.510–0.832). On logistic regression, area ≥0.7 cm² was solely predictive of targeted biopsy revealing ≥GG 2 disease (odds ratio 6.5, 1.3–32.4, p=0.022).ConclusionsNodule area ≥0.7 cm² may predict for transperineal-based targeted biopsies being positive for ≥GG 2 disease when 1–2 cores are taken.     

A protein phosphatase related to the vaccinia virus VH1 is encoded in the genomes of several orthopoxviruses and a baculovirus.

The vaccinia virus VH1 gene product is a dual specificity protein phosphatase with activity against both phosphoserine- and phosphotyrosine-containing substrates. We investigated the potential presence of VH1 analogs in other viruses. Hybridization and sequence data indicated that a phosphatase related to the VH1 phosphatase is highly conserved in the genomes of smallpox variola virus and other orthopoxviruses. The open reading frames from the raccoonpox virus and the smallpox variola virus Bangladesh major strain genomes encoding the VH1 analogs were sequenced and found to be highly conserved with the vaccinia virus VH1. An open reading frame from the baculovirus Autographa californica has sequence similarity to the VH1 phosphatase. The viral proteins appear to be structurally related to the cell cycle control protein p80cdc25. A recombinant phosphatase expressed from the baculovirus gene was found to share with the VH1 phosphatase the ability to hydrolyze substrates that contained both phosphoserine and phosphotyrosine.