Failure of cast immobilization for thumb ulnar collateral ligament avulsion fractures

PURPOSE: This report describes the early clinical experience with use of a transluminally placed endovascular graft (TPEG) covered with pre-expanded polytetrafluoroethylene (PTFE) to treat iliac artery aneurysms and fistulas. MATERIALS AND METHODS: Eight patients with iliac artery aneurysms (n = 7) and common iliac artery to common iliac vein fistula (n = 1) were treated with TPEGs. The iliac artery aneurysms were either common iliac (n = 6) or hypogastric (n = 1). All of the patients had significant comorbid diseases. The TPEG devices were made with pre-expanded PTFE sutured to Palmaz stents and delivered through 10- or 12-F sheaths. RESULTS: The aneurysms were successfully excluded in six of seven patients and the one iliac artery-to-vein fistula was successfully occluded. There were no immediate procedural complications related to the TPEG devices. Follow-up was limited (mean, 12 months), but no stenoses or occlusions of the TPEG devices were detected. The one failure was probably due to the marked tortuousity of the iliac artery, which prevented an adequate seal. CONCLUSION: In the authors' early clinical experience, the use of TPEG devices with pre-expanded PTFE successfully treated iliac artery aneurysms and an iliac artery-to-vein fistula. Although the results are encouraging, longer follow-up is necessary to better evaluate this type of treatment.     

Hypothalamic-pituitary-gonadal axis in the mutant weaver mouse

The weaver (wv) mutant mouse manifests severe locomotor defects, a deficiency in granule cells of the cerebellum, and cellular deficits in the midbrain dopaminergic system. The wv phenotype is associated with a missense mutation in the pore region of the G-protein-gated inwardly rectifying potassium channel, GIRK2. The homozygous male wv mouse is essentially infertile due to an inadequate level of sperm production. Females are fertile although they also manifest the neurological phenotype. Homozygotes of both sexes have reduced body weight. We have evaluated the hypothalamic-pituitary-gonadal axis in heterozygote and homozygote male and female wv mutants in comparison with wild-type controls. Testicular weight was significantly reduced in the homozygous males, due to degenerative changes of seminiferous epithelium. Serum and pituitary content of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were normal in all groups, and the normal sex differences were noted (FSH and LH higher in males, prolactin higher in females). Pituitary growth hormone (GH) concentration was normal, with control and mutant males showing higher GH than females. Serum testosterone levels were normal in the mutants, as was testicular testosterone. Testicular alpha-inhibin content was mildly reduced, but high in proportion to testicular weight. The defect in spermatogenesis appeared predominantly in the postmeiotic stages. In situ hybridization was consistent with expression of some GIRK2 mRNA isoforms in seminiferous epithelium. There were no significant differences between genotypes in the levels of dopamine, dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid in the mediobasal and preoptic hypothalamic regions. Homovanillic acid levels in these two areas were, however, reduced in wv homozygotes compared to wild-type animals. In the light of normal pituitary hormone levels, normal hypothalamic monoamine concentrations and normal sex differences in gonadotropins, we conclude that the infertility in the male homozygote wv mouse lies within the tubule and is probably a primary defect in the germ cells. The hormonal data suggest that Leydig cell function, and at least some aspects of Sertoli cell function, are normal in the mutant mice.     

The amplification refractory mutation system (ARMS): a rapid and direct prenatal diagnostic technique for beta-thalassaemia in Singapore

beta-Thalassaemia major patients have chronic anaemia and since 3-4 per cent of Singaporeans carry the beta-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of beta-major. Six mutations along the beta-gene were studied--41-42 (-TCTT), IVSII #654 (C-T), 17 beta (A-T), -28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54.6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the beta-trait carrying the 41-42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the beta-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at -29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our beta-thalassaemia prenatal diagnosis programme in Singapore.     

Effect of cadmium on antioxidant enzyme activities and lipid peroxidation in a freshwater field crab, Barytelphusa guerini

The kinetics of efflux of calcium mobilized from intracellular stores following activation of human neutrophils with the synthetic chemotactic tripeptide, fMLP (1 microM), as well as that of the subsequent store-operated influx of this cation, has been measured by radiometric procedures using 45Ca. These procedures enabled distinction between net efflux and influx of 45Ca. Preincubation of neutrophils in medium containing 45Ca as the sole source of Ca2+, followed by activation with fMLP, resulted in a rapid efflux of the cation, which coincided with its release from intracellular stores. Efflux terminated at approximately 30 s after addition of fMLP to neutrophils and resulted in the loss of 42 +/- 3% (P < 0.005) of cell-associated 45Ca. Net influx of 45Ca, which was insensitive to the voltage-dependent Ca2+ channel blockading agent, verapamil (20 microM), could only be detected at 30-60 s after the addition of fMLP to neutrophils, and proceeded for about 5 min, resulting in intracellular concentrations of Ca2+ which were 27 +/- 3% (P<0.05) higher than preactivation levels. These results demonstrate that the efflux of cytoplasmic Ca2+ mobilized from intracellular stores during activation of neutrophils by fMLP, and the subsequent influx of extracellular Ca2+ to replete these stores, are chronologically distinct events in fMLP-activated neutrophils.     

Evaluation of artificial neural network modelling to predict torso muscle activity

Owing to the complexities involved in obtaining direct measures of in vivo muscle forces, validation of predictive models of muscle activity has been difficult. An artificial neural network (ANN) model had been previously developed for the estimation of lumbar muscle activity during moderate levels of static exertion. The predictive ability of this model is evaluated in this study using several techniques, including comparison of response surfaces and composite statistical tests of values derived from model output, with multiple EMG experimental datasets. ANN-predicted activation levels were accurately modelled to within 3% across a range of experiments and levels of combined flexion/extension and lateroflexion loadings. The results indicate both a high degree of consistency in the averaged muscle activity measured in several different experiments, and substantiate the ability of the ANN model to predict generalized recruitment patterns. It also is suggested that the use of multiple comparison methods provides a better indication of model behaviour and prediction accuracy than a single evaluation criterion.     

Magnetic resonance imaging study of hippocampal volume in chronic, combat-related posttraumatic stress disorder

This study used quantitative volumetric magnetic resonance imaging techniques to explore the neuroanatomic correlates of chronic, combat-related posttraumatic stress disorder (PTSD) in seven Vietnam veterans with PTSD compared with seven nonPTSD combat veterans and eight normal nonveterans. Both left and right hippocampi were significantly smaller in the PTSD subjects compared to the Combat Control and Normal subjects, even after adjusting for age, whole brain volume, and lifetime alcohol consumption. There were no statistically significant group differences in intracranial cavity, whole brain, ventricles, ventricle:brain ratio, or amygdala. Subarachnoidal cerebrospinal fluid was increased in both veteran groups. Our finding of decreased hippocampal volume in PTSD subjects is consistent with results of other investigations which utilized only trauma-unexposed control groups. Hippocampal volume was directly correlated with combat exposure, which suggests that traumatic stress may damage the hippocampus. Alternatively, smaller hippocampi volume may be a pre-existing risk factor for combat exposure and/or the development of PTSD upon combat exposure.     

Mechanisms of histamine stimulated secretion in rabbit ileal mucosa

Histamine is present in high concentrations in the intestine and we investigated the possibility that it might have a role here in intestinal transport. When added to the basal side of rabbit ileal mucosa in vitro histamine (10(-4)M) induced a short-lived increase in electrical potential difference and short circuit current. It inhibited net chloride absorption but did not influence sodium transport. Alkali secretion, measured by a pH stat technique, was inhibited, suggesting that bicarbonate secretion was reduced. Both the electrical and ion flux responses to histamine were blocked by the H1 receptor blocker diphenhydramine, but not by the H2 receptor blocker cimetidine. The presence of specific H1 histamine receptors was further supported by shifts in the dose-response curve to histamine by four different concentrations of diphenhydramine. Calculation of a pA2 value from these "Schild' plots provided a figure of 7.85, which is similar to that for H1 receptors in other tissues. Aminoguanidine, a histaminase blocker, had no electrical effects alone but shifted the histamine dose response curve to the left. These studies indicate that histamine inhibits chloride absorption and alkali secretion, possibly by influencing a chloride/bicarbonate exchange process, through specific mucosal H1 receptors. Enhancement of histamine effects by a histaminase inhibitor suggests that histaminases are present in the intestinal mucosa and supports the possibility of a role for endogenous histamine in influencing ion transport. The observations indicate a mechanism by which absorption might be impaired in diseases in which histamine is liberated locally in the intestine.     

A polymorphism in exon b2 of the major breakpoint cluster region (M-bcr) identified in chronic myeloid leukaemia patients

The BCR/ABL junctional region and the b3 exon from chronic myeloid leukaemia (CML) patients were sequenced. In all 21 samples analysed the junctional region, as well as the b3 exon of 8 b3a2 mRNA molecules, presented no differences to the already described sequences. However, we identified a polymorphic base in the b2 exon in two out of seven b3a2 samples, four out of 10 b2a2 samples and all four b3a2/b2a2 samples analysed. In the eighth position before the junctional region of BCR/ABL cDNA, a cytosine replaces thymine in these cases. The polymorphism described here could be a useful marker for the differentiation of normal and rearranged BCR alleles in heterozygotes.     

11-oxygenated cytotoxic 8,9-secokauranes from a New Zealand liverwort, Lepidolaena taylorii

Four new cytotoxic 8,9-secokauranes have been identified from the liverwort Lepidolaena taylorii. The 11-oxygenation found in three of these has not been encountered in the 8,9-secokauranes known from higher plants. NMR studies were combined with molecular modelling to determine the preferred conformations. Six structurally related kauren-15-ones were also found, including three new compounds. Some of these compounds showed differential cytotoxic activity against human tumor cell lines. The probable mode of cytotoxic action was supported by Michael addition of a thiol. Two 8,9-secokauranes were the main cytotoxins in another New Zealand liverwort. L. palpebrifolia.