A behavioural characterisation of the FVB/N mouse strain

The use of transgenic models in scientific research has made an enormous contribution to our understanding of the causes and symptoms of many diseases, including neurodegenerative conditions such as Alzheimer's Disease (AD) and Parkinson's Disease (PD). In the creation of transgenic models of neurodegenerative disease, effects of the background strain of the animal on the resulting genotype must be taken into consideration. This is particularly true for behavioural studies in which the background strain of the mouse may mask the phenotype of the genetic manipulation. Here, the behaviour of two mouse strains used in transgenic models, FVB/N and C57BL6/J, were compared. Studies of circadian wheel activity, cognition and aggression revealed considerable phenotypic differences between strains. These data also indicate that the FVB/N strain is not appropriate as a background strain in the behavioural assessment of transgenic mouse models.     

Covalent dimer species of beta-defensin Defr1 display potent antimicrobial activity against multidrug-resistant bacterial pathogens

Beta defensins comprise a family of cationic, cysteine-rich antimicrobial peptides, predominantly expressed at epithelial surfaces. Previously we identified a unique five-cysteine defensin-related peptide (Defr1) that, when synthesized, is a mixture of dimeric isoforms and exhibits potent antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Here we report that Defr1 displays antimicrobial activity against an extended panel of multidrug-resistant nosocomial pathogens for which antimicrobial treatment is limited or nonexistent. Defr1 fractions were collected by high-pressure liquid chromatography and analyzed by gel electrophoresis and mass spectrometry. Antimicrobial activity was initially investigated with the type strain Pseudomonas aeruginosa PAO1. All fractions tested displayed equivalent, potent antimicrobial activity levels comparable with that of the unfractionated Defr1. However, use of an oxidized, monomeric six-cysteine analogue (Defr1 Y5C), or of reduced Defr1, gave diminished antimicrobial activity. These results suggest that the covalent dimer structure of Defr1 is crucial to antimicrobial activity; this hypothesis was confirmed by investigation of a synthetic one-cysteine variant (Defr1-1cys). This gave an activity profile similar to that of synthetic Defr1 but only in an oxidized, dimeric form. Thus, we have shown that covalent, dimeric molecules based on the Defr1 beta-defensin sequence demonstrate antimicrobial activity even in the absence of the canonical cysteine motif.     

Hepatitis B — Diagnostik und Therapie

Ohne Zusammenfassung     

Food intake and food choice: the role of the endogenous opioid peptides in the marsupial Sminthopsis crassicaudata

Endogenous opioid peptides activate food seeking behaviour and influence macronutrient choice in a number of animal species and previous studies have suggested that the palatability of food is strongly modulated by the opioid feeding system. The effect of opioid peptides on appetite and food choice in marsupials has not been evaluated. The aim of these studies was to determine the effect of μ, δ and κ opioid receptors on food intake and food choice in the marsupial Sminthopsis crassicaudata. When offered a choice of mealworms or laboratory diet after 24 h food deprivation, S. crassicaudata ate predominantly mealworms. After a 24 h fast, adult male S. crassicaudata were injected peripherally with opioid receptor antagonists or saline. Animals were re-fed with either their laboratory diet alone, or a choice of laboratory diet and mealworms. In animals re-fed with laboratory diet alone, naloxone at doses of 15 and 10 mg/kg produced a 31% (P<0.05) and 38% (P<0.05) respectively reduction in food intake in the first 30 min after laboratory diet was re-introduced, but lower doses had no effect. The selective δ antagonist naltrindole at 20 mg/kg resulted in a 65% (P<0.01) reduction in food intake compared to controls between 30 and 60 min. The selective κ opioid antagonist nor-binaltorphimine had no effect on the intake of laboratory diet. In animals offered a choice of laboratory diet and mealworms, naloxone doses of 1, 5, 10, 15 and 20 mg/kg significantly decreased intake in the first 0.5 h after re-feeding, due to a preferential suppression of the intake of mealworms. Naltrindole and nor-binaltorphimine had no effect on food choice. These studies demonstrate that endogenous opioid peptides influence both food intake and choice in S. crassicaudata and that the role of the opioid feeding system is in part modulated by food palatability. In S. crassicaudata these effects appear to occur predominantly by a μ opioid receptor mechanism.     

Peripheral INSL3 concentrations decline with age in a large population of Australian men

The novel peptide hormone insulin-like peptide 3 (INSL3) is a major secretory product of the Leydig cells of the testis, and in adult men is secreted into the blood, giving rise to circulating concentrations ranging from 0.5 to 2.5 ng/mL. We studied a large randomly recruited cohort of 1183 men from South Australia, comparing serum INSL3 concentrations with age, and a variety of endocrine, cognitive and morphological parameters. While INSL3 concentration declines significantly (p < 0.001) and continuously with age from 1.29 +/- 0.47 ng/mL in young men (age 35-44 years) to 0.79 +/- 0.39 ng/mL in the age group 75-80 years, there is no correlation with testosterone or components of the hypothalamo-pituitary-gonadal (HPG) axis, independent of age, nor with any other parameter measured, including thyroid or prostate status and obesity. For men exhibiting normal follicle stimulating hormone (FSH) and high luteinizing hormone (LH) levels, there was a significant inverse correlation with plasma oestradiol. Unilaterally orchidectomized men had INSL3 values intermediate between intact men and anorchid subjects, and showed inverse correlations (p < 0.001) between INSL3 and FSH or LH concentrations, which were independent of age. Taken together, the data show that INSL3 is an independent measure of Leydig cell function (quality and number), which appears to be independent of acute control via the HPG axis. Its decline with age reflects a decline in the properties of the Leydig cell population only, and emphasizes a gonadal component in the age-related decrease in androgen production.     

Adult-to-adult right lobe living donor liver transplantation： Comparison of endoscopic retrograde cholangiography with standard T2-weighted magnetic resonance cholangiography for evaluation of donor biliary anatomy

INTRODUCTIONOver the past decade, a critical shortage of cadaveric organs for adults in need of liver transplants has developed. The current mortality for patients awaiting liver transplantation (LTx) ranges from 20% to 30%. During this time, the waiting …     

Situs inversus of donor or recipient in liver transplantation

Situs inversus is a rare anatomical abnormality that is often associated with multiple, complex malformations. In the past, patients with situs inversus were considered unsuitable candidates for transplantation or organ donation because associated visceral, and especially vascular, anomalies pose special technical difficulties. Recently, several cases of successful liver transplantation in recipients with situs inversus have been published using modified surgical techniques. This report reviews the literature and describes our own experience, including two liver graft recipients with complete and incomplete situs inversus, and one patient who underwent successful transplantation using a liver from a donor with situs inversus. Received: 10 October 1997 Received after revision: 22 December 1997 Accepted: 9 January 1998