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Biomedical subjects

C Greenfield

Publications and source records attributed to C Greenfield.

At least 37 records · Page 2Linked to original sources
PubMed1986

Perinatal transmission of hepatitis B virus in Kenya: its relation to the presence of serum HBV-DNA and anti-HBe in the mother.

In Kenya hepatitis B virus (HBV) infection and its sequelae are common. We followed up 49 hepatitis B surface antigen (HBsAg)- positive mothers and their newborn infants for 9 months to determine the importance of perinatal transmission in the African and to relate this to the HBe and HBV-DNA status of the mother. Our study shows that perinatal transmission is relatively unimportant in Kenya and that this may be a consequence of the low levels of circulating HBV-DNA in the maternal plasma. These results imply that vaccination without hyperimmune globulin may be adequate to control HBV infection in Kenya.

DNA, Viral↗
PubMed1986

Integration of HBV-DNA may not be a prerequisite for the maintenance of the state of malignant transformation. An analysis of 110 liver biopsies.

Hundred and ten liver biopsy specimens from various parts of the world were examined for episomal and integrated HBV-DNA sequences. In 54 patients with HBsAg chronic liver disease episomal HBV-DNA was found in 83% of HBeAg-positive patients, compared to only 22% of patients with anti-HBe. Furthermore episomal HBV-DNA in the latter predominated among the Asians. Integrated HBV-DNA was found only in 5.5% of HBeAg-positive patients but in 16.5% of patients with anti-HBe. In 28 HBsAg-positive patients with hepatoma, episomal HBV-DNA was found in 50% of HBeAg-positive patients but in only 11% of anti-HBe patients. Conversely integrated sequences were less common (25%) in HBe-Ag-positive patients than in anti-HBe patients (50%), giving an overall incidence of integration in this group of 45%. No episomal, and only one case of integrated sequences of HBV-DNA, could be detected among 10 patients with HBsAg-negative hepatoma. In addition neither episomal nor integrated HBV-DNA could be detected in 18 patients with non-HBV-related liver disease. Our data suggests that stable integration of HBV-DNA into the host's genome is not necessarily a prerequisite for the maintenance of the state of malignant transformation but may be necessary for its initiation. Alternatively, the detection of integrated HBV-DNA may represent a 'snap shot' of a random integration event amplified by clonal expansion promoted by other factors.

Base Sequence↗
PubMed1986

Hepatitis delta virus infection in Kenya. Its geographic and tribal distribution.

In 1982-1984, an epidemiologic survey of the prevalence of hepatitis B virus surface antigen (HBsAg) in circulating blood (HBs-antigenemia) and of hepatitis delta virus infection was performed in Kenya. The distributions of hepatitis B virus and the delta virus were shown to be very variable. In southern Kenya, only two of 202 sera from HBsAg-positive individuals with no known liver disease and none from 123 HBsAg-positive patients with hepatitis B-related liver disease were positive for delta antibody. In contrast, in northern Kenya, there was an overall prevalence of delta antibody in healthy individuals of 31%. The distribution of delta infection is discussed in relation to lifestyle, ethnic group, and geographic area.

Adult↗
PubMed1986

Hepatitis B virus and primary liver cell carcinoma. The application of molecular biology.

Worldwide, primary liver cell carcinoma (PLC) is one of the most common tumours. Epidemiological evidence has implicated hepatitis B virus (HBV) in its aetiology and the mechanisms whereby HBV could operate at the genomic level have been investigated using the techniques of molecular biology. The resemblance of certain features of HBV to the retroviruses has also suggested mechanisms whereby malignant transformation may take place, but as yet there is no clear evidence for HBV being directly oncogenic. This has suggested to some that it is the persistent inflammatory reaction caused by HBV infection that is instrumental in causing PLC. We believe, however, that HBV can act independently of this mechanism and that the failure so far to show this at the molecular level may be due to technical reasons.

Carcinoma↗
PubMed1986

Altered expression of epidermal growth factor receptors in human bladder and lung tumours.

The expression of epidermal growth factor (EGF) receptors on 31 primary bladder and 109 lung tumours was evaluated by immunohistology using two monoclonal antibodies which recognise either the external ligand binding domain or the internal tyrosine kinase domain. At the immunocytochemical level receptor over-expression was detected at a higher frequency in squamous lung tumours than in other types of lung tumours. In the bladder tumours those with the highest level of EGF receptor expressions were invasive and poorly differentiated. In all tumours similar receptor expression levels were detected with both antibodies indicating that expression of truncated receptors is not detectable by this method. Analysis of DNA from the bladder and lung tumours failure to show gene re-arrangement, except in one unusual case of a carcinosarcoma, thus confirming these histochemical results. Gene amplification accompanied by massive overexpression of receptors was found in 1 of 29 bladder tumours and in 2 of 10 squamous cell carcinomas of the lung. The results suggest that analysis of receptor overexpression could prove useful for diagnosis of certain tumours.

ErbB Receptors↗
PubMed1985

Detection of serum HBV-DNA by molecular hybridisation. Correlation with HBeAg/anti-HBe status, racial origin, liver histology and hepatocellular carcinoma.

The relationship of the presence of hepatitis B virus (HBV) DNA in serum, a measure of HBV-replication, to HBeAg/anti-HBe status has been examined. In Northern Europe, there is a strong positive correlation between the presence of HBV-DNA and HBe antigenaemia and a negative correlation with the presence of anti-HBe. These associations are less marked in patients from Southern Europe, Africa, the Middle and Far East. When HBV-DNA is present in the serum of anti-HBe carriers, it is usually associated with the presence of severe liver disease or carcinoma. Forty percent of patients with hepatocellular carcinoma had evidence of continuing HBV replication.

Carcinoma, Hepatocellular↗
PubMed1985

Biliary sequelae of endoscopic sphincterotomy.

Twenty five patients were reviewed a mean of 36 months after successful endoscopic sphincterotomy for the removal of bile duct stones. All the patients had improved symptomatically but 20% had episodes of mild abdominal pain and a similar number had elevated serum gamma glutamyltranspeptidase activities (up to 3 times normal). In 12 patients (50%) biliary gas was demonstrated indicating reflux of duodenal contents. Clinical cholangitis did not occur. Aspiration liver biopsy revealed mild portal tract fibrosis and inflammation in patients with biliary reflux. Biliary reflux was significantly associated with mild upper abdominal pain (P less than 0.05). This study has shown that mild abnormalities of biliary function persist after endoscopic sphincterotomy. The long term consequence of these changes is unclear.

Adult↗
PubMed1984

Aetiology of acute sporadic hepatitis in adults in Kenya.

Markers for acute hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis non-A, non-B (HNANB) infections were examined in the sera of 94 patients presenting with acute hepatitis in Kenya. Hepatitis B virus was responsible for 70% of cases, HNANB for 18%, and HAV for only 12%. The use of an IgM anti-HBc assay increased the rate of diagnosis of acute HBV infection, thereby reducing the proportion of cases designated as NANB.

Acute Disease↗
PubMed1983

Clostridium difficile and inflammatory bowel disease.

Stools from 109 patients with inflammatory bowel disease (13.4%) contained Clostridium difficile or its toxin, an incidence similar to the stools of 99 control patients with diarrhoea (11.9%), but significantly higher than the stools of 77 control patients with a normal bowel habit (1.4%). Sixty-six per cent of the diarrhoea controls, but only 11% of the inflammatory bowel disease patients, reported recent antibiotic use: however, 67% of inflammatory bowel disease patients were taking sulphasalazine. The presence of Cl difficile in the stool was not related to the clinical assessment of inflammatory bowel disease relapse, but it was related to hospital admission. During the one year study, 31 of the 109 patients (28%) with inflammatory bowel disease had one or more stool samples that were positive for Cl difficile.

Anti-Bacterial Agents↗
PubMed1983

Severe ulcerative colitis during successful pregnancy.

A 31-year-old patient presented with fulminant colitis during the 27th week of her first pregnancy. Despite failed medical treatment, colectomy was delayed because of the gravid uterus. A healthy child was delivered at 32 weeks by caesarian section, but a postoperative ileus appeared to induce transient colonic dilatation. A colectomy was performed 10 days post-partum. Both mother and child survived.

Adult↗
PubMed1982

Aseptic meningitis and herpes simplex proctitis. A case report.

A male homosexual patient developed an aseptic meningitis during the course of acute ano-proctitis due to herpes simplex virus type 2 (HSV-2). Aseptic meningitis (sometimes proved to be due to HSV-2) has been associated with genital but not with anal herpes. This sexually transmissible virus should be considered when patients with aseptic meningitis are investigated.

Adult↗