Improvements are needed in the existing packaging of medicated oils containing methyl salicylate

In view of the toxic potential of medicated oils containing methyl salicylate, we have studied the existing packaging of 10 commonly used preparations from Hong Kong and Singapore and identified areas for improvement with respect to the prevention of poisonings. They were all packed in translucent bottles without child-resistant closures. The methyl salicylate content ranged from 15 to 67%. Many preparations also contained other potentially toxic ingredients in significant amounts, such as turpentine oil and camphor. The contents of the larger bottles could generally be emptied more easily because of the greater size of their openings. The product with the highest methyl salicylate content also had the biggest opening of all. The threat from ingestion of medicated oils containing methyl salicylate can probably be 'reduced' by: (i) using child-restraint closures; (ii) restricting the size of both the openings and the bottles; and (iii) reducing the methyl salicylate content.

Isolation and characterization of Vibrio carchariae, a causative agent of gastroenteritis in the groupers, Epinephelus coioides

An outbreak of serious mortality among the cultured groupers Epinephelus coioides, characterized by a swollen intestine containing yellow fluid, occurred in the summer of 1993 in Taiwan. A motile strain EmI82KL was isolated from the intestinal yellow fluid of the moribund groupers with tryptic soy agar supplemented with 2% NaCl and/or thiosulfate citrate bile salt sucrose agar. This strain was characterized and identified as Vibrio carchariae and was susceptible to chloramphenicol, doxycycline-HCl, nalidixic acid, oxolinic acid, oxytetracycline, and sulfonamide while resistant to ampicillin and penicillin G. In addition, the strain was neither auto-agglutinating nor hemagglutinating, but it was hemolytic against erythrocytes from sheep, rabbit, tilapia, and grouper. The bacteria could be reisolated from kidney, liver, and the transparent yellow fluid of swollen intestine of moribund groupers after bacterial challenge and re-identified as the same species. The LD50 value was 2.53 x 10(7) colony forming units/g grouper body weight.

The expression of nonagglutinating fimbriae and its role in Proteus mirabilis adherence to epithelial cells

Proteus mirabilis is a common causative agent of human urinary tract infections, especially in catheterized patients and in those patients with structural abnormalities of the urinary tract. In addition to the production of hemolysin and urease, fimbriae-mediated adherence to uroepithelial cells and kidney epithelium may be essential for virulence of P. mirabilis. A single P. mirabilis strain is capable of expressing several morphologically distinct fimbrial species, which can each be favoured by specific in vitro growth conditions. The fimbrial species reported to date include mannose-resistant/Proteus-like fimbriae, ambient temperature fimbriae, P. mirabilis fimbriae, and nonagglutinating fimbriae (NAF). Here, using intact bacteria or purified NAF as immunogens, we have generated the first reported NAF-specific monoclonal antibodies (mAbs). Bacteria expressing NAF as their only fimbrial species adhered strongly to a number of cell lines in vitro, including uroepithelial cell lines. Binding of P. mirabilis was markedly reduced following preincubation with NAF-specific mAbs and Fab fragments. The presence of NAF with highly conserved N-terminal sequences on all P. mirabilis strains so far examined, combined with the ability of both anti-NAF mAbs and purified NAF molecules to inhibit P. mirabilis adherence in vitro, suggests that NAF may contribute to the pathogenesis of P. mirabilis.

Effects of extracellular products of Vibrio alginolyticus on penaeid prawn plasma components

The effects of both crude extracellular products (ECP) and a partially purified protease of Vibrio alginolyticus on the plasma components of kuruma prawn (Penaeus japonicus) and tiger prawn (P. monodon) were studied using crossed immunoelectrophoresis (CIE). A component of the plasma, tentatively identified as coagulogen, apparently disappeared after incubation with the ECP, while the amount of a component tentatively identified as haemocyanin decreased. The coagulogen and an unknown component (component 1) in the penaeid plasma showed an increased migration rate after incubation with a partially purified 33 kDa protease of the bacterium. In contrast, incubation with protease had no detectable effect on the amount of haemocyanin. These events may significantly contribute to the pathogenicity of Vibrio alginolyticus in penaeids.

Effect of platelet-derived growth factor isoforms on the migration of mouse embryo limb myogenic cells

The effect of platelet-derived growth factor (PDGF) isoforms on limb myoblast migration was examined in vitro. Using Blindwell Chemotaxis chambers, the ability of PDGF-AA, -AB and -BB to stimulate the migration of myoblasts, obtained from the proximal region of 11.5 day mouse forelimb buds, was examined. Immunocytochemistry, with the anti-sarcomeric myosin antibody MF-20, was used to identify the myogenic cells in the heterogeneous cell population. Myoblasts, suspended in PDGF-free medium in the upper chamber, migrated across the polycarbonate filter of the Blindwell chamber to 1-10 ng/ml PDGF-AB and 1-100 ng/ml PDGF-BB situated in the lower well. At 1-10 ng/ml of either PDGF-AB or -BB migration increased in a dose-dependent manner. PDGF-AA, however, was unable to elicit a significant locomotory response in forelimb myoblasts. A Checkerboard assay, with various concentrations of PDGF-AA, -AB or -BB in the upper and lower wells of the chamber, indicated that -AB and -BB but not -AA stimulated the random migration of limb myoblasts. The differential effect of PDGF isoforms on myoblast migration was compared with other aspects of skeletal muscle development. At 0.1-10 ng/ml all three isoforms were able to stimulate an increase in the number of differentiated myoblasts, indicated by the expression of sarcomeric myosin, on examination after 48 h when cultured at low density. In high density cultures, however, these isoforms inhibited myoblast fusion when compared to the spontaneous fusion observed in untreated cultures. Immunohistochemical studies of both cultured limb cells and cryosections of 11.5 day whole limbs revealed that myoblasts expressed both PDGF alpha- and beta-receptors which suggests that the action of PDGF isoforms on limb myoblasts is receptor-mediated. Finally, having demonstrated that the PDGF-B monomer stimulates migration in limb myoblasts, by immunohistochemistry, the presence of PDGF-B was confirmed and its distribution examined in the 11.5 day forelimb.

Passive immunization of the tiger prawn, Penaeus monodon, using rabbit antisera to Vibrio harveyi

Passive immunization, toxicity neutralization and the persistence of passive protection in the tiger prawn (Penaeus monodon) were investigated using rabbit antisera to the formalinized extracellular products (ECP) (R alpha ECP) and/or formalinized bacterial cells (R alpha BC) of luminescent Vibrio harveyi strain 820514 originally isolated from diseased tiger prawns. Rabbit antiserum to bovine serum albumin (R alpha BSA) or phosphate-buffered saline (PBS, pH 7.2) both served as controls. The toxicity of ECP to prawns was neutralized by pre-incubation with R alpha ECP. Passive immunization by pre-injection of R alpha BC or R alpha ECP into prawns 3 d in advance protected against a lethal dose challenge of bacteria. To determine the persistence of passive protection by rabbit antiserum in tiger prawns, the R alpha BC, R alpha ECP, R alpha BSA or PBS were injected into prawns. At 10, 17 or 24 d post-immunization, groups of prawns were given a lethal dose challenge of bacteria. The prawns in the two control groups were all killed within the first 2 d following challenge at all three challenge dates. Pre-injection with R alpha BC and R alpha ECP provided total protection for 10 and 17 d, respectively, with all treated prawns surviving for at least 2 weeks post-challenge. This is the first study using mammalian antisera to investigate toxicity neutralization, passive immunization and persistence of passive protection by rabbit antisera in prawns. The results could be useful in future studies on virulence mechanisms and disease control of vibriosis in cultured prawns.

Purification and characterization of a cysteine protease produced by pathogenic luminous Vibrio harveyi

The purification and characterization of an extracellular protease produced by pathogenic luminous Vibrio harveyi strain 820514, originally isolated from diseased tiger prawn (Penaeus monodon), was presented in this paper. The purification steps included ammonium sulfate precipitation, with columns of hydrophobic interaction chromatography and anion exchange on fast protein liquid chromatography. The protease is an alkaline cysteine protease, heat labile, inhibited by iodoacetamide, iodoacetic acid, N-ethylmaleimide, p-chloromercuribenzoate, and p-chloromercuribenzene-sulfonic acid, and showed maximal activities at pH 8 and 50 degrees C, having a molecular mass of 38 kDa as estimated by SDS-PAGE and gel filtration column. In addition, the protease was also completely inhibited by CuCl2 and HgCl2, but not or only partially inhibited by other inhibitors tested. Furthermore, 2-mercaptoethanol was the most effective reducing agent in the activation of the enzyme. The present protease is the first cysteine protease found in Vibrio species.

Affinity labeling displays the stepwise activation of ICE-related proteases by Fas, staurosporine, and CrmA-sensitive caspase-8

The activation of multiple interleukin-1beta converting enzyme-related proteases (caspases) in apoptotic mammalian cells raises questions as to whether the multiple active caspases have distinct roles in apoptotic execution as well as how these proteases are organized in apoptotic signaling pathways. Here we used an affinity-labeling agent, YV(bio)KD-aomk, to investigate the caspases activated during apoptotic cell death. YV(bio)KD-aomk identified six distinct polypeptides corresponding to active caspases in Fas-stimulated Jurkat T cells. On staurosporine treatment, four polypeptides were detected. Competition experiments showed that the labeled caspases have distinct substrate preferences. Stepwise appearance of the labeled caspases in each cell death event was consistent with the view that the activated caspases are organized into protease cascades. Moreover, we found that stepwise activation of caspases similar to that induced by Fas ligation is triggered by exposing non-apoptotic Jurkat cell extracts to caspase-8 (MACH/FLICE/Mch5). Conversely, CrmA protein, a viral suppressor of Fas-induced apoptosis, inhibited the protease activity of caspase-8. Overall, these findings provide evidence that caspase-8, a CrmA-sensitive protease, is responsible for initiating the stepwise activation of multiple caspases in Fas-stimulated cells.

Fibroblast growth factors 2 and 4 stimulate migration of mouse embryonic limb myogenic cells

Fibroblast growth factors (FGFs) are believed to be vital for limb outgrowth and patterning during embryonic development. Although the effect of FGFs on the formation of the skeletal elements has been studied in detail, their effect on the development of the limb musculature is still uncertain. In this study, we used Blindwell chemotactic chambers to examine the effect of FGF-2 and FGF-4 on the motility of myogenic cells obtained from the proximal region of the day 11.5 mouse forelimbs. The limb myogenic cells were found to be chemotactically attracted to FGF-2 and FGF-4 at 10-50 ng/ml. Both FGFs increased myogenic cell migration in a dose-dependent manner, with maximal responses attained at 1-50 ng/ml for FGF-2 and at 10 ng/ml for FGF-4; however, FGF-2 was found to be a more potent chemoattractant than FGF-4. It was possible to inhibit the myogenic cells' response to FGF-2 and FGF-4 by the addition of the appropriate neutralizing antibody. The effects of FGF-2 on cell migration were further investigated by loading this cytokine into Affi-Gel blue beads and transplanting them into day 11.5 forelimb buds. The results showed that FGF-2 attracted DiI-labelled proximal cells to migrate toward the implanted beads and that the migration was more extensive than that observed in the absence of FGF-2. A checkerboard assay was performed in which various concentrations of FGF-2 and FGF-4 were introduced to both the upper and lower wells of the Blindwell chambers. The results indicated that both FGF isoforms can stimulate chemokinesis as well as chemotaxis in myogenic cells. In addition, the effect of FGF-2 at 0.1-10 ng/ml stimulated a significant increase in the number of myocytes expressing sarcomeric myosin on examination after 48 hr in culture, but the effect of FGF-4 was negligible at all concentrations analyzed; however, both FGF-2 and FGF-4 inhibited myocyte fusion compared with the spontaneous fusion observed in control cultures. Finally, we used in situ hybridization and immunohistochemical techniques to determine the distribution of myogenic cells and FGF-2 protein in the day 11.5 mouse forelimbs.

In vitro development of DNA-injected embryos co-cultured with goat oviduct epithelial cells in Korean native goats ()

In vitro development of Korean native goat embryos was investigated in 2 different culture systems with and without goat oviduct epithelial cells (GOEC). Estrus was synchronized by inserting intravaginal progestagen-impnegnated sponge (Veramix) containing 60 mg medroxyprogesterone acetate (MAP) for 14 d. Superovulation was induced with follicle stimulating hormone (FSH). Goat ova were surgically obtained by retrograde flushing the oviducts of does at 66 to 68 h after MAP removal. Mean number of recovered ova per doe was 7.28 +/- 3.91, and the proportion of fertilized embryos in recovered ova was 66.5% (121/182 ). Fertilized embryos were cultured for 9 d in CR1aa medium supplemented with 10% estrous goat serum (EGS) at 38.5 degrees C, 5% CO(2) in air. There was no difference in development of the embryos to the morula stage between the 2 culture systems (84.4 and 84.0%, respectively). However, developmental rate to blastocysts (65.6%) of the embryos co-cultured with GOEC was significantly higher than of those (12.0%) cultured without GOEC (P < 0.001). Goat zygotes were injected with bovine beta-casein/human lactoferrin cDNA fusion gene (pBL1). When the DNA-injected embryos were co-cultured with GOEC, developmental rates of the embryos to the morula and blastocyst stages were 82.9 and 36.6%, respectively. The results obtained in this study indicate that "blocking" of in vitro development of Korean native goat embryos appears to occur at the morula stage, but can be overcome to some extent by co-culture with GOEC. In the co-culture system, DNA-injected goat embryos could successfully develop to normal hatching blastocysts.

Quantitative analysis of bacterial toxin affinity and specificity for glycolipid receptors by surface plasmon resonance

The primary virulence factors of many pathogenic bacteria are secreted protein toxins which bind to glycolipid receptors on host cell surfaces. The binding specificities of three such toxins for different glycolipids, mainly from the ganglioside series, were determined by surface plasmon resonance (SPR) using a liposome capture method. Unlike microtiter plate and thin layer chromatography overlay assays, the SPR/liposome methodology allows for real time analysis of toxin binding under conditions that mimic the natural cell surface venue of these interactions and without any requirement for labeling of toxin or receptor. Compared to conventional assays, the liposome technique showed more restricted oligosaccharide specificities for toxin binding. Cholera toxin demonstrated an absolute requirement for terminal galactose and internal sialic acid residues (as in GM1) with tolerance for substitution with a second internal sialic acid (as in GD1b). Escherichia coli heat-labile enterotoxin bound to GM1 and tolerated removal or extension of the internal sialic acid residue (as in asialo-GM1 and GD1b, respectively) but not substitution of the terminal galactose of GM1. Tetanus toxin showed a requirement for two internal sialic acid residues as in GD1b. Extension of terminal galactose with a single sialic acid was tolerated to some extent. The SPR analyses also yielded rate and affinity constants which are not attainable by conventional assays. Complex binding profiles were observed in that the association and dissociation rate constants varied with toxin:receptor ratios. The sub-nanomolar affinities of cholera toxin and heat-labile enterotoxin for liposome-anchored gangliosides were attributable largely to very slow dissociation rate constants. The SPR/liposome technology should have general applicability in the study of glycolipid-protein interactions and in the evaluation of reagents designed to interfere with these interactions.

Alkaline serine protease is an exotoxin of Vibrio alginolyticus in kuruma prawn, Penaeus japonicus

An extracellular lethal toxin produced by Vibrio alginolyticus strain Swy originally isolated from diseased kuruma prawn(Penaeus japonicus) was partially purified by Fast Protein Liquid Chromatography with hydrophobic interaction (Phenyl Sepharose Hig hPerformance) chromatography and gel filtration columns. The toxin is an alkaline serine protease, inhibited by phenyl-methylsulfonyl fluoride (PMSF),and showed maximal activity at pH 10, having a molecular weight of about 33kDa estimated by SDS-PAGE and gel filtration chromatography. In addition, the toxin was also completely inhibited by FeCl2 but partially inhibited by CaCl2, CuCl2, CoCl2,MnCl2, and ZnCl2, and not inhibited by ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis(beta-amino-ethyl ether)N,N,N',N'-tetraacetic acid (EGTA), iodoacetamide, pepstatin A, sodium dodecylsulfate (SDS), and N-tosyl-l-phenyl-alanine chloromethyl ketone (TPCK). Both the crude extracellular products (ECP) and the partially purified toxin are lethal for kuruma prawn at LD50 values of 0.30 and 0.27 microg protein/g body weight, respectively. The addition of PMSF completely inhibited the lethal toxicity of both the ECP and the partially purified toxin, indicating that this serine protease is a lethal factor produced by the bacterium. The 33-kDa protease is, therefore, suggested to be a new toxic protease produced by V. alginolyticus strain Swy.

An index for assessing blindness in a multi-centre clinical trial: disulfiram for alcohol cessation--a VA cooperative study

This paper considers an index to assess the success of blinding with application to a clinical trial of disulfiram. The index increases as the success of blinding increases, accounts for uncertain responses, and is scaled to an interval of 0.0 to 1.0, 0.0 being complete lack of blinding and 1.0 being complete blinding.

Isolation and characterization of neutralizing single-chain antibodies against Xenopus mitogen-activated protein kinase kinase from phage display libraries

MAP kinase kinase (MAPKK) is a dual specificity protein kinase that phosphorylates and activates MAP kinase in vivo. In this study, four mouse monoclonal single-chain Fv (scFv) antibodies (Y1-6, Y1-7, Y3-6, and Y3-11) that can specifically bind to Xenopus MAPKK were isolated from combinatorial scFv-displaying phage libraries. Three scFv clones (Y1-6, Y1-7, and Y3-6) were shown to efficiently inhibit MAPKK activity in vitro. Point mutation (D98K) at VH-CDR3 of one (Y1-6) of these three clones markedly reduced its neutralizing activity. The wild-type scFv (Y1-6) inhibited the Mos-induced MAP kinase activation and germinal vesicle breakdown when injected into immature Xenopus oocytes, whereas the mutant scFv, Y1-6 (D98K), did not. The three neutralizing scFv clones (Y1-6, Y1-7, and Y3-6) were shown to bind to NH2-terminal residues 1-23 of Xenopus MAPKK, whereas the epitope of a Y3-11 clone with no neutralizing activity was shown to lie between residues 33 and 67 of MAPKK. Furthermore, a synthetic peptide (the N16 peptide) corresponding to residues 2-17 of MAPKK suppressed the neutralizing activity of the wild-type Y1-6, and a rabbit polyclonal antibody against the N16 peptide was found to possess a strong neutralizing activity against MAPKK. These results demonstrate that the neutralizing antibodies characterized here inhibit the kinase activity of MAPKK by binding to the NH2-terminal segment of MAPKK.

Factors affecting in vivo viability of DNA-injected bovine blastocysts produced in vitro

In vitro matured and fertilized bovine ova were microinjected with pBL1, which consisted of the bovine beta-casein gene promoter, human lactoferrin cDNA and SV40 polyadenylation signal. Of the 2931 zygotes injected, 2505 (85.5%) survived 1 h after DNA injection and were cultured in 50-microl drops of CR1aa medium containing 3 mg/ml BSA under mineral oil at 39 degrees C, 5% CO2 in air. Cleaved (2- to 8-cell) embryos were selected at approximately 48 h after DNA injection and then cultured further in 50-microl drops of CR1aa medium supplemented with 10% (v/v) FBS. Blastocysts were classified into 4 quality grades and 3 developmental stages by morphological criteria. Then all but poor quality blastocysts were nonsurgically transferred to the uterus of heifers 7 to 8 d after natural estrus. Following transfer, the recipients were observed for signs of estrus, and pregnancy was confirmed by palpation per rectum at approximately 60 d of gestation. Although 72.0% (1804/2505 ) of the DNA-injected zygotes reached 2- to 8-cell stages only 5.2% (131/2505) developed to blastocysts. A total of 75 DNA-injected, in vitro cultured blastocysts were transferred to 59 recipients. When 2 blastocysts were transferred to a single recipient, only the better quality embryo was counted. The overall pregnancy rate was 30.5% (18/59 ) and reflected 1) an apparent correlation between the quality of embryos and the pregnancy rate. However, the difference was not statistically significant. 2) expanded blastocysts had a higher pregnancy rate (50.0%, 11/22 ) than early (13.3%, 2 15 ) or mid (22.7%, 5/22 ) blastocysts with a significant difference between expanded and early blastocysts (P < 0.05). 3) the pregnancy rate of DNA-injected blastocysts was higher when they were transferred at Day 7 (34.5%, 10/29 ) or 8 (36.8%, 7/19 ) than at Day 6 (9.0%, 1/11 ). The results indicate that the developmental stage of DNA-injected bovine embryos may be one of contributing factors in improving the pregnancy rate after transfer, although the effects of the quality and culture period of the embryos may not be inconsequential.

The needs and sources of drug information among pharmacists in Hong Kong

The objective of this study was to determine the drug information needs of pharmacists in Hong Kong, the sources of drug information available and the constraints limiting their ability to fulfil drug information needs at practice sites. A questionnaire survey was carried out in January 1995 of community (230 retail pharmacies, 10 outpatient clinics) and 44 hospital pharmacists working in Hong Kong. The information sought included: place of practice, availability of reference texts, journals or periodicals at practice sites, types of clinical pharmacy services provided, frequency and types of drug information questions received, sources of drug information used, needs for a drug information service, and constraints limiting their ability to fulfil drug information needs at practice sites. Ninety-four pharmacists (hospital 68.2%, community 26.6%) responded. Hospital pharmacists generally had more reference texts and journals/periodicals at practice sites than community pharmacists. The majority of pharmacists in this survey were involved in a variety of clinical pharmacy services, including the delivery of drug information to other health-care professionals and the general public. Community pharmacists were most often asked questions about over-the-counter drugs, drug dosage and drug identification. Hospital pharmacists were most often asked questions about drug identification and availability of drugs. The most important drug information sources for both the community and hospital pharmacists were their own knowledge and work-place reference texts. Few pharmacists frequently used the service provided by the national Drug and Poisons Information Bureau (DPIB). The scarcity of drug information sources was perceived as an important constraint by both community and hospital pharmacists when fulfilling drug information needs at practice sites. Lack of time was considered an equally important constraint by the hospital pharmacists. A national drug information service was generally felt to be necessary. In conclusion, inadequacy in drug information sources was perceived to be a very important constraint limiting the pharmacists surveyed in fulfilling drug information needs at their individual practice sites. However, many were unaware that the drug information requested was already available. Regular attempts to publicize this territory-wide DPIB are obviously needed.

Isolation of Vibrio harveyi from diseased kuruma prawns Penaeus japonicus

Outbreaks of high mortality among the cultured kuruma prawn Penaeus japonicus without overt gross signs occurred during August and December of 1994 in I-Lan, Taiwan. Eleven luminous bacterial strains were isolated from the hepatopancreas of moribund prawns from five different farms by use of tryptic soy agar (TSA, supplemented with 2% NaCl) and/or thiosulfate citrate bile salt sucrose (TCBS) agar. These strains, together with our two previously unpublished isolates, were characterized and identified to be Vibrio harveyi in comparison with two ATCC Type strains and one strain previously isolated from the tiger prawn, P. monodon.

An index for assessing blindness in a multi-centre clinical trial: disulfiram for alcohol cessation--a VA cooperative study

This paper considers an index to assess the success of blinding with application to a clinical trial of disulfiram. The index increases as the success of blinding increases, accounts for uncertain responses, and is scaled to an interval of 0.0 to 1.0, 0.0 being complete lack of blinding and 1.0 being complete blinding.

Inhibition of histamine synthesis by glycyrrhetinic acid in mast cells cocultured with Swiss 3T3 fibroblasts

The effect of glycyrrhetinic acid (18-O-beta-glycyrrhetinic acid, GA) on histamine metabolism was investigated in cultured mast cells (CMCs) cocultured with Swiss 3T3 fibroblasts. GA strongly inhibited histamine synthesis in the cocultured CMCs. Since 50 microM GA inhibited about 80% of histidine decarboxylase (HDC) activity, the inhibitory activity of GA for histamine synthesis was considered to be derived from the inhibition of HDC activity. The number of berberine-sulfate-positive cells also decreased in the presence of GA, which indicated that maturation of CMCs was inhibited by GA. Furthermore, we examined the effect of GA on the mRNA expression of novel protein kinase C delta (nPKC delta), a major isoform of CMCs, by northern blot analysis. The expression of nPKC delta mRNA in the presence of GA was significantly lower than in the absence of GA. These results suggest the possibility that the inhibition of histamine synthesis by GA is regulated by nPKC delta.

Promotion potential of tamoxifen on hepatocarcinogenesis in female SD or F344 rats initiated with diethylnitrosamine

The liver promotion potential of tamoxifen (TAM), which has been widely used in the treatment of hormone-dependent breast cancers, was investigated using female SD or F344 rat initiated with diethylnitrosamine (DEN). In Experiment 1, 45 newborn female SD rats were administered DEN (100 mg/kg, i.p.) (Groups 1 and 2) or saline (Group 3) 24 h after birth. After weaning at week 3, Groups 1 and 3 were subcutaneously injected with TAM citrate (1 mg/rat per day), suspended in corn oil, in the subscapular region, while Group 2 was given the vehicle alone (s.c.) daily for 9 weeks, and killed at week 12. In Experiment 2, 70 female F344 rats at 7 weeks of age were divided into five groups. All animals were initially given DEN (200 mg/kg i.p.) for initiation. Two weeks later Groups 1-4 were given diets containing 100, 250, 500 ppm TAM, or 500 ppm PB for 6 weeks, respectively, while Group 5 was administered basal diet as a control for the same period. The rats were subjected to two-thirds partial hepatectomy (PH) at week 3 and were killed at week 8. The enhanced development of glutathione S-transferase-placental form (GST-P)-positive liver cell foci after DEN exposure in both newborn SD and adult F344 rat medium-term liver bioassay models (Experiments 1 and 2). This suggests that TAM exerts promotion potential for hepatocarcinogenesis in female rats.

Myoelectric activity and absorptive capacity of rat small intestinal isografts

The effect of transplantation on small intestinal absorption, digestive capacity, myoelectric activity, and morphology was assessed in inbred Lewis rats. Electrodes were sutured to the duodenum and isografted jejunoileum or to the native jejunoileum in controls. The frequency of migrating myoelectric complexes (MMCs) in the duodenum was 3.3 +/- 0.3/hr in controls and 1.8 +/- 0.4/hr in transplants (P < 0.05). MMC frequency in the jejunoileum was 5.1 +/- 1.3/hr in controls and 3.2 +/- 0.9/hr in transplants (P > 0.05). MMCs appeared to migrate from the duodenum to the jejunoileum 80 +/- 3% of the time in controls and 59 +/- 7% of the time in transplant rats (P < 0.05). Absorption in the transplanted jejunoileum demonstrated a 35-40% decrease in glucose and electrolytes absorption. Villus height and number of nuclei per villus was reduced. Intestinal length (dry) was 103 +/- 6 cm for controls and 51 +/- 3 cm for transplant rats (P < 0.05). Brush border sucrase activity was unchanged. We conclude that small intestinal isografts display similar myoelectric activity as controls, but the decreased absorptive capacity and villus height may require longer segments of intestine to be transplanted in order to support normal nutrition.

The short insulin tolerance test: feasibility study using venous sampling

The short insulin tolerance test (ITT) is both a simple and valid method of quantifying insulin sensitivity although arterialization of samples and the risk of hypoglycaemia remain as potential difficulties. We examined the safety and reproducibility of using venous sampling with insulin doses of 0.1 U kg-1 and 0.05 U kg-1 in healthy subjects. Whole blood glucose concentrations were measured contemporaneously and the rate of plasma glucose decline (mmol l-1 min-1) for each test was estimated from unlogged venous plasma glucose concentrations measured at 1 min intervals. The mean rates of plasma glucose decline for the 0.1 U kg-1 and 0.05 U kg-1 insulin doses were 0.26 mmol l-1 min-1 (n = 11, range = 0.17-0.41, intrasubject coefficient of variation (CV) = 9.4%) and 0.25 mmol l-1 min-1 (n = 6, range 0.19-0.46, intrasubject CV = 15.9%), respectively. Reversal of significant hypoglycaemia was necessary in one subject before 15 min post-insulin. We found that: (1) venous sampling provides a reproducible measure of glucose uptake after insulin, (2) contemporaneous bedside glucose sampling identifies those at risk of significant hypoglycaemia during the ITT, and (3) the 0.1 U kg-1 dose response is more reproducible and no less safe than the half dose response. We conclude that the current ITT protocol would be made safer and simpler with the above modifications although further studies comparing venous with arterialized sampling are needed.

Anti-adhesin antibodies that recognize a receptor-binding motif (adhesintope) inhibit pilus/fimbrial-mediated adherence of Pseudomonas aeruginosa and Candida albicans to asialo-GM1 receptors and human buccal epithelial cell surface receptors

Pseudomonas aeruginosa and Candida albicans were reported to adhere to the glycosphingolipid asialo-GM1 by means of pili and fimbriae, respectively. These diverse adhesins have been previously reported to have an immunologically conserved antigenic epitope and the role of this cross-reactive epitope in adherence to asialo-GM1 was investigated in this study. Both the unbiotinylated PAK pilus and fimbrial adhesins inhibited biotinylated pili from P. aeruginosa PAK and biotinylated C. albicans fimbriae binding to asialo-GM1 and receptors present on human buccal epithelial cells (BECs), which suggested that the same receptor sites were recognized by the two adhesins. Monoclonal antibodies PK99H and Fm16 raised against the P. aeruginosa PAK pili and C. albicans fimbriae, respectively, recognized a conserved epitope present on the two adhesins. Both Fm16 and PK99H blocked fimbriae binding to asialo-GM1 and BEC receptors and also inhibited P. aeruginosa and C. albicans whole cell binding to BECs. These data suggested that the conserved epitope confers receptor-binding properties to the adhesins, demonstrated that (i) asialo-GM1-like receptors present on epithelial cell surfaces are utilized by the pilus and fimbrial adhesins and (ii) the binding to these glycoreceptors is mediated by a conserved epitope that has receptor-binding properties.