Simon C. Robson

Fibrin degradation product D‐dimer induces the synthesis and release of biologically active IL‐1β, IL‐6 and plasminogen activator inhibitors from monocytes in vitro

Summary Disseminated intravascular coagulation, characterized by circulating fibrin(ogen) degradation products (FDP), is associated with both acute and chronic inflammatory conditions. Since the association of FDP with monocytes could influence the release of cytokines and other regulatory proteins with significant clinical ramifications, we have studied cytokine synthesis and release following the interaction of D‐dimer (DD), a terminal degradation product of fibrin, with human monocytes in vitro.

Evidence that the GBV‐C/hepatitis G virus is primarily a lymphotropic virus

GB virus‐C and the hepatitis G virus (GBV‐C/HGV) are variants of the same positive sense RNA flavivirus, initially thought to be associated with hepatitis. The tissue tropism of GBV‐C/HGV in normal subjects has not been evaluated to date using an extended tissue spectrum. Therefore, the sites of GBV‐C/HGV replication were investigated in serum and twenty‐three tissues collected during post‐mortem examination of four apparently healthy individuals who died accidental deaths, who were infected with GBV‐C/HGV. All were anti‐HIV and anti‐HCV negative and three out of four were HBsAg negative. Tissues were collected carefully to prevent cross contamination. A highly strand‐specific RT‐PCR assay was employed for the detection of either GBV‐C/HGV positive strand RNA (virion) or negative strand RNA (replicative intermediary). Strand specificity of the RT‐PCR assay was assessed with synthetic positive‐and negative strand GBV‐C/HGV RNA generated from a plasmid, using T7 and T3 RNA polymerases. The spleen and bone marrow biopsies were found to be uniformly positive for both negative‐and positive strand GBV‐C/HGV RNA. In addition, one cadaver was positive for both RNA strands in the kidney, and another positive for both in the liver. No negative strand RNA was detected in the following: brain, muscle, heart, thyroid, salivary gland, tonsil, lung, lymph nodes, gall bladder, pancreas, oesophagus, stomach, small bowel, large bowel, adrenal gland, gonad, aorta, skin and cartilage. This preliminary study concludes that GBV‐C/HGV is a lymphotropic virus that replicates primarily in the spleen and bone marrow. J. Med. Virol. 61:52–58, 2000.

Isolation from human fetal liver of cells co-expressing CD34 haematopoietic stem cell and CAM 5.2 pancytokeratin markers

BACKGROUND/AIMS Ductal plate and bile duct cells in developing human liver express haematopoietic stem cell markers, such as c-kit and CD34, in association with cytokeratin markers CAM 5.2 and CK 18. The identification of such ductal plate cells as likely progenitors for both bile duct epithelial cells and hepatocytes and their possible reappearance as oval cells in the regenerating liver have generated much interest in their pluripotential capacities. This study aimed to isolate cells from human fetal liver that co-express haematopoietic stem cell and epithelial cell markers. METHODS Human fetal liver was harvested following legal termination of pregnancy at week 14-22. CD34+ mononuclear cells were isolated from liver cell suspensions with immunomagnetic beads. Immunofluorescent staining, using anticytokeratin CAM 5.2 against CK 8 and 18, was performed on permeabilised CD34+ cells for flow cytometry and fluorescent microscopy. CD34+ cells were also stained for other stem cell markers (HLA-DR, c-kit) and committed haematopoietic cell markers (CD33, CD38). RESULTS Approximately 0.9% (range 0.07-4.0%) of the mononuclear cells isolated were CD34+ cells. The number of mononuclear cells isolated correlated with fetal liver weight (r=0.508). About 3-8% of these CD34+ cells stained positively for CAM 5.2. In addition, CD34+ cells were positive for HLA-DR, but only a small percentage was positive for c-kit. Staining for the committed haematological markers, CD33 and CD38, was consistently negative. CONCLUSIONS This study describes an immunoaffinity method for the enrichment from human fetal liver of cells that co-express haematopoietic stem cell and epithelial cell markers. Such cellular subsets may correspond to pluripotential ductal plate and bile duct cells.

Molecular characterization of the 5' non-coding region of South African GBV-C/HGV isolates: major deletion and evidence for a fourth genotype.

GB virus C/hepatitis G virus (GBV‐C/HGV) has been characterised as a novel flavivirus, and to date three known genotypes have been cloned. Greater genetic variation of GBV‐C/HGV has been demonstrated in West African isolates, but no major deletions have been shown in the 5′ non‐coding region (NCR). The 5′NCR regulates protein translation via an internal ribosomal entry site (IRES). We cloned, sequenced, and analysed a 344‐bp polymerase chain reaction (PCR) product, representing >60% of the 5′NCR, from 32 GBV‐C/HGV PCR‐positive volunteers. Wild‐type virus amplicons were detected in all samples. However, 5/32 (15.6%) also amplified another fragment of between 205 and 231 bp. Sequence analysis showed all cloned PCR fragments to be GBV‐C/HGV‐specific. A typical deletion of 113–131 bp with minor variation was detected in isolates generating the smaller bands. RNA secondary structure analysis showed the deletions to be over domains II and III. This finding suggests that nucleotides 303–444 may be non‐essential for 5′NCR functioning. Phylogenetic analysis demonstrated a novel fourth South African genotype, distinct from genotypes 1–3 with DNA distances of >0.1000. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values for the wild‐type and mutant samples were normal. This study documents the first major deletion in the 5′NCR of GBV‐C/HGV, and suggests that bases 303–444 may not be essential for viral replication and ribosomal entry. A fourth GBV‐C/HGV genotype appears to predominate in South Africa. J. Med. Virol. 59:52–59, 1999.

Autonomic neuropathy in extra-hepatic portal vein thrombosis: evidence for impaired autonomic reflex arc.

BACKGROUND/AIMS Autonomic dysfunction is common in cirrhosis, and may be associated with increased mortality and hyperdynamic circulatory changes. Our aim was to investigate whether autonomic disturbances occur in extrahepatic portal vein thrombosis and their correlation with hemodynamic abnormalities. PATIENTS AND METHODS Heart rate variation in response to standing, deep breathing, and Valsalva maneuver, and blood pressure response to sustained handgrip and to standing, were studied in 16 subjects with portal vein thrombosis (10 males, 30.8+/-2.8 years: mean+/-SE), 12 with cirrhosis (7 males, 52+/-2.3 years), and 10 healthy controls (7 males, 30.8+/-3.0 years). Supine resting, and 10- and 30-min standing epinephrine and norepinephrine levels were measured and results correlated with cardiac output. RESULTS Autonomic dysfunction occurred in 62% of portal vein thrombosis and 75% of cirrhosis subjects, but in no controls (p<0.02). Similarly, postural hypotension occurred in portal vein thrombosis (-10.25+/-0.65 mmHg, p=0.003) and cirrhosis (-7.42+/-0.82 mmHg, p=0.007) but not in controls. All groups had similar baseline epinephrine and norepinephrine concentrations. Epinephrine increased significantly in controls (45%, p<0.01 and 49%, p<0.02) after 10 of 30 min standing but not in the portal vein thrombosis or the cirrhotic group, and norepinephrine increased after 10 and 30 min standing in cirrhotics (128%, p<0.004 and 130%, p<0.008) and controls (129%, p<0.002 and 116%, p<0.004), but not portal vein thrombosis (34.5% and 39%, NS vs baseline). Portal vein thrombosis and cirrhosis groups had increased cardiac output (4441+/-509 and 3262+/-292) vs controls (1763+/-212 ml/min/m2, p<0.002), but there was no correlation with autonomic neuropathy or with catecholamine levels. CONCLUSIONS Autonomic dysfunction and impaired catecholamine response to orthostatic stress occur commonly in portal vein thrombosis and suggest an impairment of the autonomic reflex arc, but changes do not correlate with hemodynamic abnormalities.

Hepatitis E in South Africa : Evidence for sporadic spread and increased seroprevalence in rural areas

Hepatitis E virus (HEV) is a major cause of non‐A, non‐B hepatitis in developing countries. Factors influencing sporadic spread of hepatitis E are unclear. We examined anti‐HEV seroprevalence and demographic data from 407 urban and 360 rural black South African adults living in formal housing, squatter camps, or mud huts. Anti‐HEV seroprevalence ranged from 5.8% to 19.1% (mean 10.7%) in the different regions. Mean urban and rural rates were 6.6% and 15.3%, respectively (P = 0.0001). Rural mud hut dwellers, using unchlorinated river water, were at greater risk (17.4%) than rural villagers (5.3%; P = 0.008). A linear relation was found between seroprevalence and age, suggesting sporadic spread. The high prevalence in mud hut dwellers suggests that contaminated water plays a major role in HEV spread in South Africa. Routine chlorination or boiling of river drinking water before consumption may reduce HEV infection.

A GLORIA traverse over the marginal fracture zone and continental margin of SE Africa

Abstract A geological and physiographical interpretation of nearly 60,000 km 2 of the continental margin of SE Africa (21°20′E to 31°E) has been made using GLORIA sonographs and seismic and bathymetric records. These data have enhanced our understanding of the structural complexity of basement and sedimentary features, in particular the marginal fracture ridge (MFR), which forms part of the Agulhas-Falkland Fracture Zone (AFFZ). Most of the 500 km long exposed section can be traced in the sonographs, and it is concluded that the MFR is not a single lineament, but consists of two en-echelon basement ridges that overlap by approximately 20 km in the vicinity of the Scrutton Ridge (23.5°E). The latter is an enigmatic basement sliver that may be a narrow upthrust block. East of 26°E a major slump and canyon province has been identified in the southwestern part of the Natal Valley. Here we record three previously undescribed canyons, (Padrone, Boesmans and Fish), and extensive compressional structures in the distal parts of a large slump lobe.

The influence of cyclosporine A therapy on sex hormone levels in pre- and post-menopausal women with primary biliary cirrhosis

The mechanism underlying sex hormone disturbances in post-menopausal women with primary biliary cirrhosis is unclear, but these alterations may occur as a consequence of liver disease. As cyclosporine may have some therapeutic potential is this condition, we have evaluated short-term alterations in plasma sex hormone levels in 11 pre- and 19 post-menopausal women with primary biliary cirrhosis following randomisation to cyclosporine A or placebo therapy. Baseline sex hormone binding globulin levels were markedly depressed in all pre-menopausal women but were elevated for the post-menopausal group when compared to standard reference ranges. Testosterone and dihydrotestosterone levels were low or markedly depressed in both patient groups. Androstendione concentrations tended to be higher than the normal range in the post-menopausal group. Oestradiol levels were within the normal range for the pre-menopausal group but were relatively higher in the post-menopausal group than in other normal post-menopausal women. Cyclosporine A therapy resulted in significant decreases in sex hormone binding globulin levels (26.6 +/- 5.0 to 16.2 +/- 4.6 nmol/l; p < 0.05) in the premenopausal group and reduction in total (336 +/- 163 to 140 +/- 132 pmol/l; p < 0.01) and free (6 +/- 5 to 2 +/- 3 pmol/l; p < 0.05) oestradiol levels in the post-menopausal group at 6 months. There were no significant alterations in other hormonal parameters. No temporal changes occurred in the placebo group. Cyclosporine A therefore induces significant but variable sex hormone changes in both pre- and post-menopausal women with primary biliary cirrhosis.

Treatment of Primary Biliary Cirrhosis with Ciclosporin (CyA): Pilot Study

Primary biliary cirrhosis (PBC) is accompanied by disturbances of the immune system [6]. Thus, although it is unclear whether these disturbances have any significance in the aetiopathogenesis of PBC, many immunomodulatory drugs have been used to treat PBC [8]. Administration of corticosteroids has been associated with improvement of liver function tests but there has been no controlled trial of their efficacy.