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Biomedical subjects

C Parsons

Publications and source records attributed to C Parsons.

At least 73 records · Page 4Linked to original sources
PubMed1986

Relationship between hepatitis B virus DNA in blood and serological markers of hepatitis B infection.

The hepatitis B virus (HBV) DNA dot-hybridization assay has been introduced into clinical practice in Australia and its behaviour compared with that of the classic markers of HBV infection. A good correlation exists between the presence of HBV DNA and that of hepatitis B e antigen but the degree of dissociation between HBV DNA and the e:anti-e system was smaller than earlier studies would suggest. Patients who are seronegative for hepatitis B surface antigen (HBsAg), whether they possess anti-HBs, anti-HBc HBc (antibody to the core antigen), or neither antibody, gave uniformly negative results for the presence of HBV DNA. Theses results are different from those that were obtained from earlier studies of patients with chronic liver disease.

Acute Disease↗
PubMed1985

Risk factors associated with hepatitis B infection in antenatal patients.

Risk factors associated with HBsAg carriers were prospectively examined in 1821 women attending the Antenatal Clinic of an inner-city obstetrics hospital. Of the sample, 3.2% were HBsAg carriers and 28.7% of 725 tested for anti-HBs were positive. Birth in a country where the prevalence of HBsAg is high and Aboriginal ancestry were the major associated factors rather than a past history of hepatitis or intravenous drug use. Women from Indochina or the Pacific region, if HBsAg-positive, were more likely than other carriers to have markers of viral replication including HBeAg, hepatitis B virus (HBV) DNA, and DNA polymerase. Evidence of past infection with HBV also varied with country of birth, but 11% of women with no apparent risk factors for prior HBV infection were anti-HBs positive. This study indicates the need for a screening programme for HBsAg in antenatal populations.

Australia↗
PubMed1983

Assessment of response of bone metastases to systemic treatment in patients with breast cancer.

Seventy-one patients with breast cancer and bone metastases, together with other assessable sites of disease, were monitored by radiologic skeletal survey, bone scanning, pain charts, bone marrow aspirate, serum calcium, alkaline phosphatase and urine hydroxyproline/creatinine ratio. On the basis of UICC criteria of response in nonosseous sites, 37 were classed as responders and 34 as nonresponders. Responding patients with osteolytic disease frequently showed sclerosis, but only at 6-8 months, whereas patients with mixed lytic/sclerotic or sclerotic metastases frequently showed no change or further sclerosis. Nonresponders most frequently showed progressive lysis. Bone scanning showed clear evidence of improvement or deterioration in 7/21 responders and 8/23 nonresponders who showed no definite evidence of progression or response on skeletal radiography. Pain assessment was also useful in these patients. Neither the bone marrow aspirate nor other biochemical tests were useful in assessing response to therapy. This study concludes that bone scanning and pain assessment are both useful in assessment of response of bone metastases to treatment in some patients and incorporation into a standard criteria of response is recommended.

Alkaline Phosphatase↗
PubMed1981

lambda altSF: a phage variant that acquired the ability to substitute specific sets of genes at high frequency.

We report the isolation of lambda altSF, a variant of Escherichia coli phage lambda that substitutes sets of genes at high frequency. Two forms of the variant phage have been studied: lambda altSF lambda, which exhibits the immunity (repressor recognition) of phage lambda, and lambda altSF22, which exhibits the immunity of Salmonella phage P22. Lysates made from single plaques of lambda altSF lambda contain 10-30% phage of the P22 form. Similarly, lysates from single plaques of lambda altSF22 contain as much as 1% phage of the lambda form. Heteroduplex analyses reveal the following features of the lambda altSF chromosomes: (i) each form has the immunity genes appropriate to its immune phenotype, (ii) the substituted segments include genes involved in regulation and replication, and (iii) the alt phages have unusual additions and substitutions of DNA not normally found associated with either immunity region. In the case of lambda altSF lambda, there is a small insertion in the region of the cI gene. Because revertants that lose this inserted DNA concomitantly lose the ability to substitute, we conclude that the insertion plays a role in the substitution process. In the case of change from lambda altSF lambda to lambda altSF22, the substituting P22 genes are derived from the E. coli host. We have identified a set of Salmonella phage P22 genes in a standard nonlysogenic strain of E. coli K-12 that is apparently carried in a silent form. The reason for this lack of expression is not obvious, because this P22 material includes structural genes and associated promoters and is potentially active. When this set of genes substitutes for the analogous set of genetic material on the genome of lambda altSF lambda, the P22 genes are expressed in a normal manner.

Bacteriophage lambda↗
PubMed1980

An Australian experience of hepatitis B infection, cirrhosis and hepatocellular carcinoma.

A review of 180 patients with either chronic hepatitis or hepatocellular carcinoma (HCC) indicate a significant association. 40 patients with chronic hepatitis were seen between 1975-79. 6/25 of chronic active hepatitis and 7/15 with chronic persistent hepatitis were HBsAg positive (RIA). In the 41 patients with HCC, 15 (37%) were alcoholic, 10 cirrhosis (HBsAg positive), 5 haemochromatosis 5 cryptogenic cirrhosis, 2 probably due to sex steroids and in 4 no aetiological factor was apparent. HBsAg was present in 10/22 (45%) of HCC with cirrhosis, 15/256 (6%) for alcoholic cirrhosis, 5/16 (33%) for haemachromatosis and 5/30 (16%) cryptogenic cirrhosis. 8/80 (10%) who had acute viral hepatitis (B) are antigen positive at 6 months. This report shows that Hepatitis B virus infection is now a significant causes of liver injury in 180 patients studied. The majority of patients who have HBsAg positive cirrhosis do not have a history of acute hepatitis.

Australia↗