Body habitus in a cohort of HIV-seropositive and HIV-seronegative injection drug users

We determined anthropometric measurements (including height, weight, circumferences, and skinfolds) and self-reported symptoms related to body habitus changes in 324 HIV-seropositive and HIV-seronegative inner city injection drug users (IDUs) who participated in a substudy from the ALIVE (AIDS Linked to Intravenous Experiences) cohort. Participants who reported lipoatrophy in body parts had consistently lower anthropometric measurements and those reporting adiposity had correspondingly higher anthropometric measurements than participants who did not report these changes. Peripheral lipoatrophy was more common among all HIV-seropositive than HIV-seronegative participants, however, it was not associated with highly active antiretroviral therapy (HAART) (39% HIV-seronegatives; 58% HIV-seropositive not receiving HIV treatment [No Tx]; 49% HAART, p = 0.04). Central adiposity was more common among HAART (52%) than No Tx (26.6%) and HIV-seronegative (42%) participants (p = 0.001). However, waist circumference, while somewhat higher among HAART than No Tx participants, did not differ significantly from HIV-seronegative participants (85.2 cm HIV-seronegatives; 83.3 cm No Tx; 85.8 cm HAART). A large proportion of those who reported peripheral lipoatrophy also reported central lipoatrophy (76.9% HIV-seronegatives; 69.6% No Tx; 66.2% HAART). A large proportion of those who reported central adiposity also reported adiposity of the peripheral sites (88.1% HIV seronegatives; 66.7% No Tx; 74.3% HAART). The combination of lipoatrophy and adiposity was associated with HAART treatment (6% HIV-seronegatives; 3% No Tx; 16% HAART, p = 0.002), but may be driven by the association with adiposity. These data suggest validity of self-reports for body habitus changes among injection drug users.     

Treatment of compulsive behaviour in eating disorders with intermittent ketamine infusions

We have previously shown that eating disorders are a compulsive behaviour disease, characterized by frequent recall of anorexic thoughts. Evidence suggests that memory is a neocortical neuronal network, excitation of which involves the hippocampus, with recall occurring by re-excitement of the same specific network. Excitement of the hippocampus by glutamate-NMDA receptors, leading to long-term potentiation (LTP), can be blocked by ketamine. Continuous block of LTP prevents new memory formation but does not affect previous memories. Opioid antagonists prevent loss of consciousness with ketamine but do not prevent the block of LTP. We used infusions of 20 mg per hour ketamine for 10 h with 20 mg twice daily nalmefene as opioid antagonist to treat 15 patients with a long history of eating disorder, all of whom were chronic and resistant to several other forms of treatment. Nine (responders) showed prolonged remission when treated with two to nine ketamine infusions at intervals of 5 days to 3 weeks. Clinical response was associated with a significant decrease in Compulsion score: before ketamine, mean +/- SE was 44.0 +/- 2.5; after ketamine, 27.0 +/- 3.5 (t test, p = 0.0016). In six patients (non-responders) the score was: before ketamine, 42.8 +/- 3.7; after ketamine, 44.8 +/- 3.1. There was no significant response to at least five ketamine treatments, perhaps because the compulsive drive was re-established too soon after the infusion, or because the dose of opioid antagonist, nalmefene, was too low.      

Assembly of Weibel-Palade body-like tubules from N-terminal domains of von Willebrand factor

Endothelial cells assemble von Willebrand factor (VWF) multimers into ordered tubules within storage organelles called Weibel-Palade bodies, and tubular packing is necessary for the secretion of VWF filaments that can bind connective tissue and recruit platelets to sites of vascular injury. We now have recreated VWF tubule assembly in vitro, starting with only pure VWF propeptide (domains D1D2) and disulfide-linked dimers of adjacent N-terminal D'D3 domains. Assembly requires low pH and calcium ions and is reversed at neutral pH. Quick-freeze deep-etch electron microscopy and three-dimensional reconstruction of negatively stained images show that tubules contain a repeating unit of one D'D3 dimer and two propeptides arranged in a right-handed helix with 4.2 units per turn. The symmetry and location of interdomain contacts suggest that decreasing pH along the secretory pathway coordinates the disulfide-linked assembly of VWF multimers with their tubular packaging.     

Manipulation of liver regeneration with macrophages to influence the hepatic progenitor cell niche

Insufficient regeneration of the adult liver is believed to cause failure to recover from severe liver disease. An undifferentiated cell population with stem-cell-like qualities known as hepatic progenitor cells (HPCs) is hypothesised to have a central role in regeneration of the adult liver during massive or chronic liver disease. Stem cells in other organ systems are believed to reside in a specialised microenvironment or niche that supports their maintenance and function. The existence of a hepatic stem cell niche might provide a means of therapeutically manipulating endogenous HPCs in vivo as a regenerative therapy.To investigate the physiological potential of HPCs to regenerate the mammalian liver, we have established a novel model of hepatocellular injury and HPC activation using genetic manipulation of hepatocytes. After hepatocyte senescence and death in this model (AhCre Mdm2^flox), HPCs expand and bring about the complete regeneration of the liver parenchyma.We demonstrate that a stereotypical niche, consisting partly of macrophages, exists in both animal models and correlating human disease. Using cell tracking, we show active recruitment of extrahepatic macrophages into this niche during injury. In health, intravenous injection of macrophages results in macrophage engraftment to the liver niche, with subsequent HPC activation and changes to liver structure and function.Within the niche, macrophages use paracrine signalling to control both HPC proliferation and cell fate via TWEAK (tumour-necrosis-factor-like weak inducer of apoptosis) and the Wnt signalling pathway, respectively. After hepatocellular injury, macrophages ingest hepatocyte debris, and release Wnt which promotes HPC differentiation into hepatocytes. TWEAK is vital for HPC proliferation in the AhCre Mdm2^flox model of regeneration. Here, the absence of TWEAK signalling results in liver failure and mortality.This work has demonstrated for the first time the ability of a solid organ to fully regenerate in the adult mammal from progenitor cells, and additionally highlights mechanisms by which this process can be modulated by either small molecule or cell therapy.FundingUniversity of Edinburgh.     

Evidence for direct action of human biosynthetic (recombinant) GM-CSF on erythroid progenitors in serum-free culture

The biologic activity of human biosynthetic granulocyte-monocyte colony stimulating factor (GM-CSF) was investigated in serum-free culture of erythroid progenitors derived from adult peripheral blood. The morphology of erythroid bursts and the cloning efficiency of BFU-E under serum-free conditions were similar to those observed in dishes with fetal bovine serum (FBS). For these experiments, progenitor cells were partially purified by Ficoll-Paque density centrifugation, adherence to a plastic surface, and complement-mediated cytotoxicity of Leu-1+ elements. For some studies, blastlike cells were harvested directly from 6-day-old semisolid cultures. In serum-free culture of the light-density cell fraction, biosynthetic erythropoietin (Ep) was sufficient for formation of pure and mixed erythroid colonies whereas GM-CSF was required for granulocyte-monocytic colonies. When adherent and Leu-1+ cells were removed, or when in vitro differentiated blast cells were used as a source of progenitors, neither Ep or GM-CSF alone induced colony formation. In dishes supplemented with both growth factors, erythroid bursts were detected. Although the presence of GM- CSF alone did not induce formation of any colony or clusters, BFU-E were recorded when Ep was added 8 days later, suggesting that BFU-E could be maintained. Terminal maturation of the resulting erythroid bursts was delayed by 8 days. These results provide evidence that GM- CSF acts directly on early erythroid progenitors. Furthermore, they suggest that both Ep and GM-CSF are necessary to start the differentiation process.     

Hepatitis B virus subgenotypes and basal core promoter mutations in Indonesia

AIM： To identify the distribution of hepatitis B virus （HBV） subgenotype and basal core promoter （BCP） mutations among patients with HBV-associated liver disease in Indonesia.
METHODS： Patients with chronic hepatitis （CH, n =61）, liver cirrhosis （LC, n = 62）, and hepatocellular carcinoma （HCC, n = 48） were included in this study. HBV subgenotype was identified based on S or preS gene sequence, and mutations in the HBx gene including the overlapping BCP region were examined by direct sequencing.
RESULTS： HBV genotype B （subgenotypes B2, B3, B4, 85 and B7） the major genotype in the samples, accounted for 75.4%, 71.0% and 75.0% of CH, LC and HCC patients, respectively, while the genotype C （subgenotypes C1, C2 and C3） was detected in 24.6%, 29.0%, and 25.0% of CH, LC, and HCC patients, respectively. Subgenotypes B3 （84.9%） and C1 （82.2%） were the main subgenotype in HBV genotype B and C, respectively. Serotype adw2 （84.9%） and adrq＋ （89.4%） were the most prevalent in HBV genotype B and C, respectively. Double mutation （A1762T/G1764A） in the BCP was significantly higher in LC （59.7%） and HCC （54.2%） than in CH （19.7%）, suggesting that this mutation was associated with severity of liver disease. The T1753V was also higher in LC （46.8%）, but lower in HCC （22.9%） and CH （18.0%）, suggesting that this mutation may be an indicator of cirrhosis.
CONCLUSION： HBV genotype B/B3 and C/C1 are the major genotypes in Indonesia. Mutations in BCP, such as A1762T/G1764A and T1753V, might have an association with manifestations of liver disease.     

Chemokine expression and leucocyte infiltration in Sjogren's syndrome

OBJECTIVE: To investigate the expression and source of chemokines in minor salivary gland biopsies (MSGs) in patients with Sjogren's syndrome (SS). METHODS: Immunohistochemical analysis was used to determine the pattern of chemokine expression in MSGs from patients with (n=6) and without (n=5) SS, as well as to examine the phenotype of both resident and infiltrating cells expressing chemokines. RESULTS: Significant differences in the number of infiltrating mononuclear (MN) cells in patients with and without SS were noted. Ductal epithelial cells of SS biopsies expressed significantly increased levels of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, interleukin-8 (IL-8) and RANTES (Regulated upon Activation, Normal T cell Expressed and Secreted). Biopsies from patients with SS showed that MIP-1beta was expressed by 51% of infiltrating cells, while 41% expressed MIP-1alpha, whereas 22 and 7% expressed RANTES and IL-8, respectively. CONCLUSION: Chemokines expressed by ductal epithelial cells may attract circulating leucocytes, in particular CD4+ T cells, towards the site of inflammation, thereby orchestrating the influx of MN cells characteristically seen in MSGs in SS. Chemokines may be induced directly by a putative triggering agent for SS, or secondary to the release of pro-inflammatory cytokines produced by epithelial cells. These findings further implicate epithelial cells as playing a major role in the pathogenesis of SS and implicate chemokines in the leucocyte recruitment in this setting.