Genomic screen for loci associated with alcohol dependence in Mission Indians.

Alcohol dependence is a leading cause of morbidity and mortality in Native Americans, yet biological factors underlying the disorder in this ethnic group remain elusive. This study's aims were to map susceptibility loci for DSM-III-R alcohol dependence and two narrower alcohol-related phenotypes in Mission Indian families. Each participant gave a blood sample and completed an interview using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) that was used to make alcohol dependence diagnoses and the narrower phenotypes of withdrawal, and drinking severity. Genotypes were determined for a panel 791 microsatellite polymorphisms. Analyses of multipoint variance component LOD scores for the dichotomous DSM-III-R phenotype revealed no peak LOD scores that exceeded 2.0 at any chromosome location. Two chromosomes, 4 and 12, had peak LOD scores that exceeded 2 for the alcohol use severity phenotype and three chromosomes 6, 15, 16 were found to have peaks with LOD scores that exceeded 2 for the withdrawal phenotype. Evidence for linkage to chromosomes 4 and 15, and 16 have been reported previously for alcohol related phenotypes whereas no evidence has as yet been reported for chromosomes 6 and 12. Combined linkage and association analysis suggest that alcohol dehydrogenase 1B gene polymorphisms are partially responsible for the linkage result on chromosome 4 in this population. These results corroborate the importance of several chromosomal regions highlighted in prior segregation studies in alcoholism and further identify new regions of the genome that may be unique to either the restricted phenotypes evaluated or this population of Mission Indians.     

Pulsed-field gel electrophoresis as an epidemiologic tool for enterococci and streptococci

Enterococci (Enterococcus faecium and Enterococcus faecalis) and streptococci such as Streptococcus pyogenes (Group A streptococcus), Streptococcus agalactiae (Group B streptococcus), and Streptococcus pneumoniae are increasing in importance as both hospital-acquired and community pathogens. Emerging resistance and increasing incidence of these organisms has necessitated the analysis of their epidemiologic mechanisms of spread. Pulsed-field gel electrophoresis (PFGE) has emerged as the one of the most widely applicable, reproducible, and stable methods to examine strain identity in bacterial organisms. The procedure used in our laboratory for PFGE typing of whole cell DNA digested with SmaI for enterococci, S. pneumoniae, S. pyogenes, and S. agalacatiae is presented. Issues regarding interpretation are also reviewed and discussed.     

Copolymerization of ε-caprolactone and morpholine-2,5-dione derivatives

Novel biodegradable poly(ester-amide)s were prepared by ring-opening copolymerization of ε-caprolactone and 3- and/or 6-alkyl-substituted morpholine-2,5-dione derivatives. The copolymerizations were carried out in the bulk using stannous octoate as an initiator. Molecular weights of the copolymers ranged from 1,0 · 10⁴ to 8,3 · 10⁴ and decreased with increasing mole fractions of morpholine-2,5-dione derivatives in the feed. ¹³C NMR sequence analysis indicated that the copolymers had a random distribution of ε-oxycaproyl and depsipeptide units, which resulted from the occurrence of transesterification reactions during copolymerization. The results of the DSC measurements and ¹³C NMR sequence analysis showed a close relationship between the crystallinity and average length of ε-oxycaproyl blocks. Copolymers with a mole fraction of depsipeptide units smaller than 0,20 were semi-crystalline, whereas incorporation of larger amounts of depsipeptide units resulted in amorphous copolymers. The melting point depression as a function of the molar composition of the semi-crystalline copolymers was in good agreement with the melting point depression predicted by the Baur equation, which indicated the rejection of depsipeptide units from crystals consisting of ε-oxycaproyl units.     

Role of phagocytic macrophages in induction of contact hypersensitivity and tolerance by hapten applied to normal and ultraviolet B-irradiated skin.

Liposomes containing the drug dichloromethylene diphosphonate (Cl2MDP) can eliminate phagocytic cells, such as macrophages, when injected in vivo. In this paper we report that Cl2MDP-containing liposomes have been used experimentally to determine the extent to which cutaneous macrophages participate (1) in the induction of contact hypersensitivity (CH) when hapten is painted on normal murine skin, and (2) in the induction of CH or tolerance when hapten is painted on murine skin that has been exposed to ultraviolet B (UVB) radiation. Intradermal (i.d.) injections of Cl2MDP-containing liposomes were found to have no deleterious effects on CH induction via normal skin, whether the amount of hapten (dinitrofluorobenzene) applied to the cutaneous surface was optimal or excessive. Moreover, Cl2MDP-containing liposomes did not deplete the epidermis of Langerhans' cells. However, similar i.d. injections of Cl2MDP-containing liposomes did prevent the induction of CH when hapten was painted on UVB-irradiated skin of BALB/c mice, a strain that develops CH when hapten is applied to UVB-exposed skin. These findings indicate that the antigen-presenting cell (APC) function found in skin of UVB-resistant mice following exposure to UVB radiation can be attributed to macrophages. This explains why these mice develop and display CH after UVB radiation. By contrast, i.d. injections of Cl2MDP-containing liposomes failed to prevent the induction of the tolerance when hapten was applied to the surface of UVB-exposed skin of UVB-susceptible mice, such as C57BL/6. Since the dermis of UVB-exposed skin of these mice is known to contain a novel population of cells that can provide a tolerance-conferring signal, the current findings rule out macrophages as the responsible cell type.     

Orosensory Perception of Fat/Sweet Stimuli and Appetite-Regulating Peptides before and after Sleeve Gastrectomy or Gastric Bypass in Adult Women with Obesity

The aim of this study was to explore the impact of bariatric surgery on fat and sweet taste perceptions and to determine the possible correlations with gut appetite-regulating peptides and subjective food sensations. Women suffering from severe obesity (BMI > 35 kg/m²) were studied 2 weeks before and 6 months after a vertical sleeve gastrectomy (VSG, n = 32) or a Roux-en-Y gastric bypass (RYGB, n = 12). Linoleic acid (LA) and sucrose perception thresholds were determined using the three-alternative forced-choice procedure, gut hormones were assayed before and after a test meal and subjective changes in oral food sensations were self-reported using a standardized questionnaire. Despite a global positive effect of both surgeries on the reported gustatory sensations, a change in the taste sensitivity was only found after RYGB for LA. However, the fat and sweet taste perceptions were not homogenous between patients who underwent the same surgery procedure, suggesting the existence of two subgroups: patients with and without taste improvement. These gustatory changes were not correlated to the surgery-mediated modifications of the main gut appetite-regulating hormones. Collectively these data highlight the complexity of relationships between bariatric surgery and taste sensitivity and suggest that VSG and RYGB might impact the fatty taste perception differently.     

Triplications of chromosome 1p36.3, including the genes GABRD and SKI,are associated with a developmental disorder and a facial gestalt

Triplication of chromosomal region 1p36.3 is a rare genomic rearrangement. In this report, we delineate the phenotypic spectrum associated with 1p36.3 triplications. We describe four patients with microtriplications of variable size, but with a strong phenotypic overlap, and compare them to previously described patients with an isolated triplication or duplication of this region. The 1p36.3 triplication syndrome is associated with a distinct phenotype, characterized by global developmental delay, moderate intellectual disability, seizures, behavioral problems, and specific facial dysmorphic features, including ptosis, hypertelorism, and arched eyebrows. The de novo occurrence of these microtriplications demonstrates the reduced reproductive fitness associated with this genotype, in contrast to 1p36.3 duplications which are mostly inherited and can be associated with similar facial features but with a less severe developmental phenotype. The shared triplicated region encompasses four disease-related genes of which GABRD and SKI are most likely to contribute to the phenotype.     

Cadmium in beavers translocated from the Elbe river to the rhine/meuse estuary,and the possible effect on population growth rate

Beavers (Castor fiber) from the Middle Elbe region were re-introduced in the Biesbosch, The Netherlands, an estuary contaminated with cadmium (Cd) by the rivers Rhine and Meuse. The Middle Elbe region was also polluted with Cd, but the beavers released in the Biesbosch originated from two relatively clean habitats within this region. The Biesbosch population grew slower than other released beaver populations in Europe, and it was hypothesized that Cd intoxication was responsible for this. The beavers fed primarily on the bark and leaves of willow and poplar trees, which contained great concentrations of Cd. The average Cd concentration in the food (6.9 g/g_dry) was above the maximum tolerable concentration for large domestic herbivores. The Cd concentrations of the kidneys and hair of the beavers were correlated with those in the bark of the trees. The Cd concentration in the hair increased threefold after the release in the Biesbosch, and the geometric mean Cd kidney concentration was 55 g/g_dry. Using three different models, an average Cd kidney concentration in the beavers of >100 g/g_dry was predicted in the Biesbosch in the near future. Such a concentration causes kidney damage in some other mammals. Beaver kidneys from the Mulde, a tributary of the Elbe, contained on average 467 g Cd/g_dry, the greatest concentration reported in herbivores. Nevertheless, the fertility along the Mulde was high, due to the fact that it is an otherwise optimal beaver habitat. Furthermore, the low fertility in the Biesbosch was due to a small fraction of successful breeding pairs. We conclude that the initial low population growth rate in the Biesbosch was probably not caused by contamination with Cd. However, future effects on the individual (reproductive) life span cannot be ruled out.     

Functional assessment of sciatic nerve reconstruction: biodegradable poly (DLLA-epsilon-CL) nerve guides versus autologous nerve grafts

The aim of this study was to compare functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with modified denatured muscle tissue (MDMT), or an autologous nerve graft. We evaluated nerve recovery using walking track analysis (measurement of the sciatic function index [SFI]) and electrostimulation tests. Functional nerve recovery after reconstruction with a biodegradable p(DLLA-epsilon-CL) nerve guide filled with MDMT was faster when compared with nerve reconstruction using an autologous nerve graft. We conclude that in case of a short nerve gap in the rat, reconstruction can best be carried out using a p(DLLA-epsilon-CL) biodegradable nerve guide filled with MDMT.     

Detection of migrated allogeneic oligodendrocytes throughout the central nervous system of the galactocerebrosidase-deficient twitcher mouse

Summary Galactocerebrosidase-deficient oligodendrocytes of twitcher (twi/twi) mice degenerate prematurely. Transplantation of normal bone marrow cells has been shown to alleviate symptoms and to prolong survival time. However, characteristic ataxia (twitching) is not cured. In an attempt to improve further the condition of twitcher mice, allogeneic foetal liver cells were transplanted as a source of normal haemopoietic stem cells and supplemented with intracerebral transplantation of foetal brain cells. A reliable method was developed to detect donor-type cells in brain tissue. Bacteriophage . transgenic foetal mice were used as donors of both foetal liver and brain cells. Integrated copies of . DNA in donor cells were detected byin situ hybridization with biotinylated probes, which were then stained using streptavidin alkaline phosphatase. This technique was combined with immunohistochemistry to distinguish donor-type oligodendrocytes from macrophages. Immunoperoxidase staining with an antiserum to carbonic anhydrase-II produced dark perikarya of oligodendrocytes. The results demonstrated that local foetal brain cell grafts resulted in a wide dissemination of donor-type oligodendrocytes throughout the twitcher brain. The addition of a foetal brain cell graft to haemopoietic cell transplantation resulted in significantly prolonged survival of twitcher mice.