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C H Thompson

Publications and source records attributed to C H Thompson.

At least 91 records · Page 5Linked to original sources
PubMed1992

Enzyme-linked immunosorbent assay for measurement of IgG antibody to Molluscum contagiosum virus and investigation of the serological relationship of the molecular types.

An ELISA was developed for measuring levels of IgG antibodies to Molluscum contagiosum virus (MCV) using DNA typed purified virus as antigen. The assay was found to be specific and sensitive for antibodies to MCV as well as being economical in its use of antigen. A close relationship was found between antibody levels to the MCV molecular types 1, 1v and 2 by cross-testing sera on plates coated with the different molecular types of the virus as antigen (P < 0.001).

Adult↗
PubMed1992

Proton efflux from rat skeletal muscle in vivo: changes in hypertension.

1. An analysis of the recovery kinetics of intracellular pH and phosphocreatine concentration after exercise in skeletal muscle was developed to calculate the rate of proton efflux in vivo. 2. Recovery of rat leg muscle pH after sciatic nerve stimulation was faster in spontaneously hypertensive rats than in Wistar-Kyoto controls (both n = 5). 3. Analysis of these data showed that the rate of proton efflux depends on intracellular pH, being greater at lower pH. 4. The early rate of proton efflux was greater in spontaneously hypertensive rats [measured over the first 0.8 min, 12.5 mmol min-1 kg-1 (SEM 1.8) in spontaneously hypertensive rats compared with 7.6 mmol min-1 kg-1 (SEM 0.4) in Wistar-Kyoto rats, P less than 0.05], even though pH at the start of recovery was higher [6.30 (SEM 0.03) in spontaneously hypertensive rats compared with 6.17 (SEM 0.01) in Wistar-Kyoto rats, P less than 0.01]. 5. This novel analysis provides a quantitative estimate of the rate of proton efflux in vivo, and demonstrates directly that this is increased in spontaneously hypertensive rats, as has previously been inferred from pH changes during exercise and studies of cultured muscle cells in vitro.

Animals↗
PubMed1992

Effect of bicarbonate administration on skeletal muscle intracellular pH in the rat: implications for acute administration of bicarbonate in man.

1. The effect of bicarbonate administration on the intracellular pH of rat skeletal muscle was examined by using 31P n.m.r. 2. Bicarbonate administered intraperitoneally caused a significant intracellular acidosis in rat skeletal muscle in vivo. When the bicarbonate was administered intravenously there was no such change in the pH of the skeletal muscle. 3. Bicarbonate administration by either route resulted in an elevated mixed venous partial pressure of carbon dioxide and an elevated arterial pH, but no significant change in the arterial partial pressure of carbon dioxide. The increase in arterial bicarbonate concentration after intraperitoneal injection of bicarbonate was delayed when compared with that after intravenous injection. 4. The administration of hypertonic solutions intravenously caused a transient 40-50% fall in blood pressure, which had resolved within 1 min. 5. The data suggest that the effect of bicarbonate administration on intracellular pH in vivo is related not only to carbon dioxide loading of the cell but also to the rate of change in the extracellular bicarbonate concentration.

Animals↗
PubMed1992

Changes in high-energy phosphates in rat skeletal muscle during acute respiratory acidosis.

We used 31P magnetic resonance spectroscopy to study changes in phosphorus metabolite concentrations in rat skeletal muscle during respiratory acidosis (14 and 20% inspired CO2) and recovery. As intracellular pH fell (from 7.05 to 6.75 after 20 min of 20% CO2), intracellular [P(i)] increased by up to 50% while phosphocreatine concentration decreased by up to 8%. The sum of all intracellular phosphates remained constant. [ADP] decreased by up to 40% in accordance with the creatine kinase equilibrium but the phosphorylation potential [ATP]/([ADP][P(i)]) was preserved as a result of increased [P(i)]. This adjustment may be a mechanism for maintaining mitochondrial ATP synthesis despite low pH. Eventually this increase in cellular [P(i)] could lead to slow efflux of P(i) from the skeletal muscle cell contributing to the hyperphosphataemia of acute respiratory acidosis.

Acidosis, Respiratory↗
PubMed1991

Detection of human papillomavirus type 16 E6/E7 transcripts in fixed paraffin-embedded cervical cancers by the polymerase chain reaction.

A simple, and sensitive method for the detection of human papillomavirus (HPV) 16 E6/E7 transcripts in RNA purified from formalin acetic alcohol (FAA)-fixed, paraffin embedded cervical cancer (CaCx) tissue is described. The entire procedure, including polymerase chain reaction (PCR) amplification of cDNA obtained from mRNA by reverse transcription, can be completed within a day. The results obtained compare favourably with those using total nucleic acids extracted from the same fixed material, and are consistent with results using RNA purified from corresponding fresh tumour tissue. Although developed for investigating the expression of HPV in tumours, this method should find general application in studies of gene expression and viral detection.

DNA, Single-Stranded↗
PubMed1991

Na+/H+ and HCO3-/Cl- exchange in the control of intracellular pH in vivo in the spontaneously hypertensive rat.

1. We have previously shown that the cytosolic acid concentration changes in skeletal muscle during contraction in spontaneously hypertensive rats and normotensive Wistar-Kyoto rats in vivo. We have now found that this change was unaffected by 20% inhaled CO2 or by 4,4'-di-isothiocyanostilbene-2,2'-disulphonate. This is evidence that HCO3- exchange in vivo is not important in the control of cytosolic acid concentration during skeletal muscle contraction in either spontaneously hypertensive or Wistar-Kyoto rats. 2. We have also previously shown that the difference in cytosolic acid response during contraction between spontaneously hypertensive and Wistar-Kyoto rats is due to increased Na+/H+ antiporter activity in the spontaneously hypertensive rats. Our current findings suggest that this increase in Na+/H+ antiporter activity is more likely to be due to a change in the Km of the antiporter than to a change in the Vmax. We estimate that the Km of the antiporter changes in hypertension from pH 7.16 to 7.33. 3. We did not find any differences between adult spontaneously hypertensive and Wistar-Kyoto rats with regard to resting intracellular and extracellular pH and resting intracellular and extracellular HCO3- concentrations. In addition, we did not find any evidence of a difference in skeletal muscle HCO3-/Cl- exchange between adult spontaneously hypertensive and Wistar-Kyoto rats. 4. At rest, skeletal muscles of the spontaneously hypertensive and Wistar-Kyoto rats have the same lactate production, HCO3-/Cl- exchange and arterial partial pressure of CO2. In addition, we can also calculate that at a resting intracellular pH of 7.05 in the spontaneously hypertensive rats, the antiporter is 66% saturated.(ABSTRACT TRUNCATED AT 250 WORDS)

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1991

Factors associated with clinical and sub-clinical anal human papillomavirus infection in homosexual men.

OBJECTIVES: (I) to determine the relative sensitivities of clinical examination, cytology and HPV DNA hybridisation for the detection of anal human papillomavirus infection; and (ii) to examine various factors which may influence presentation of anal human papillomavirus infection in homosexual men. METHODS AND RESULTS: 112 unselected homosexual men attending a Sydney STD clinic for routine screening underwent a complete anogenital and physical examination, during which blood samples (for haematological, serological and immunological investigations), rectal swabs (for culture of anal pathogens) and anal scrapes of the dentate line (for cytology and HPV DNA hybridisation) were collected. Papanicolaou-stained anal smears were examined for cytological abnormalities, including those indicative of HPV infection or anal intraepithelial neoplasia (AIN). HPV DNA was detected by high stringency dot hybridisations using radiolabelled HPV 6, 11, 16 and 18 DNA probes. Visible anal condylomata, situated either externally or in the anal canal, were present in 26% of these men; 46% had cytological evidence of HPV infection, and 19% of the smears showed evidence of mild to moderate dysplastic changes (AIN I-II). Detectable HPV DNA was present in 40% of the anal scrapes. By combining these results, a total of 73 men (65%) were found to have at least one of the indicators of HPV infection. These data, together with that relating to HIV antibody, immune status and past or present infection with other STDs, was correlated with information obtained from a questionnaire administered to the patients at the time of their clinical examination. CONCLUSIONS: In this study cytology was found to be slightly more sensitive than HPV DNA dot hybridisation for the detection of HPV infection in the anal canal, providing the full range of HPV-associated cytological changes were accepted as a basis for diagnosis. Clinical anal lesions were more likely to be detected in young men, men who had symptomatic HIV infection and those with a history of past anal wart infection. The latter group also had a higher incidence of cytologically apparent HPV infection in their anal smears. There was a significant association between the detection of HPV 16/18 and the presence of anal dysplasia, but there were no significant correlations between HPV infection or anal dysplasia and HIV antibody, immune function status, sexual practices or history of other STDs.

Adolescent↗
PubMed1991

Anal intercourse: a risk factor for anal papillomavirus infection in women?

OBJECTIVE: To determine whether anal intercourse is a risk factor for anal HPV infection in women. DESIGN: Results derived from clinical examination, anal cytology and HPV DNA hybridisation were correlated with data obtained from a questionnaire administered to the patients at the time of their clinical examination. SETTING: A sexually transmitted diseases (STD) clinic in Sydney, Australia. SUBJECTS: 31 women attending the clinic for HPV related problems. METHODS AND RESULTS: A thorough history was elicited from each woman followed by physical examination of the anogenital region. Cervical and anal scrapes were collected for cytology and HPV DNA hybridisation. Of the 15 women who practised anal intercourse, a total of 12 (80%) had either clinical or subclinical HPV infection. Seven had overt anal warts, situated either internally or externally in the anal canal; and further 5 women had evidence of subclinical HPV infection as determined by positive cytological and/or HPV DNA hybridisation results on their anal scrapes. The women who did not have a history of anal intercourse had a lower (7/16, 43%), but not statistically significant, rate of anal HPV infection: five had anal warts and two had subclinical evidence of infection. No correlations were found between anal HPV infection and genital (cervical, vulval or vaginal) HPV infection; nor between the HPV typing patterns of women in either group. CONCLUSION: The results obtained from these women do not indicate a close relationship between anal intercourse and the presence of detectable anal HPV infection.

Adult↗
PubMed1991

Deleterious effects of formalin/acetic acid/alcohol (FAA) fixation on the detection of HPV DNA by in situ hybridization and the polymerase chain reaction.

As part of a study of archival cervical cancer specimens (1920s to 1980s) to determine whether changes have occurred in the prevalence of human papillomavirus (HPV) DNAs, investigations were performed on tissues which had been fixed in either 10% buffered formalin (NBF) or formalin-acetic acid-alcohol (FAA). HPV DNA was detected by in situ hybridization (ISH) using HPV 6, 11, 16 and 18 32P-labelled DNA probes under conditions of high stringency; and by the polymerase chain reaction (PCR) using 20-mer oligonucleotide primers to amplify 109 bases of the E6 region of HPV 16. In some instances results obtained from Southern blot hybridizations, which had been carried out on specimens of fresh cancer tissue, were available for comparison. When tissues had been fixed in NBF, HPV DNA sequences were detected in 53% of specimens by ISH and in 72% by PCR. In comparison, the rates of detection of HPV by ISH and PCR in tissues fixed in FAA were 17% and 21% respectively. These results indicate that FAA is clearly inferior to NBF for the preservation of detectable HPV DNA sequences in tissue sections.

Acetates↗
PubMed1990

Molecular epidemiology of Australian isolates of molluscum contagiosum.

Molluscum contagiosum lesions obtained from 75 Australian patients, 22 (29%) of whom were HIV positive, were examined by restriction endonuclease analysis and Southern blot hybridisation using radiolabelled and digoxigenin-labelled MCV DNA probes. The isolates were classified (MCV 1, 1v, 2, and 2v) on the basis of these results, which were in turn correlated with the clinical features of each lesion. A total of 44 (59%) of the lesions contained MCV 1 or 1v, 24 (32%) contained MCV 2 or 2v, three (4%) contained multiple MCV types, whereas four (5%) of lesions submitted contained no detectable MCV DNA. The ratio of MCV 1/1v to MCV 2/2v was determined to be approximately 1.75:1. There were substantial differences between the distribution of MCV types 1 and 2 among patients of different age groups, but no significant relationship between MCV type and the sex of the patient was found. MCV 2 was more frequently detected in lesions from anogenital areas and in immunosuppressed (HIV-positive) patients, and MCV 1 was more commonly isolated from skin rather than genital lesions, but neither association was statistically significant. Fragment F (10 kbp) obtained from the genome of MCV 1 was capable of differentiating MCV 1 from MCV 2 when used as a probe in hybridisation experiments with BamHI cut samples and may be useful when small amounts of lesion prevents differentiation by direct visualisation of restriction endonuclease fragments.

Adult↗
PubMed1990

Automated polymerase chain reaction for papillomavirus screening of cervicovaginal lavages: comparison with dot-blot hybridization in a sexually transmitted diseases clinic population.

The aim of the present study was to compare the recently developed polymerase chain reaction (PCR) technique with conventional dot-blot DNA hybridization for human papillomavirus (HPV) detection. Cells were collected by cervicovaginal lavage from a study group of 109 women attending a sexually transmitted diseases clinic. Using a machine that we developed for alternation of temperature cycles, HPV was detected in 51% of patients by PCR. By dot-blot hybridization, 44% of the patients were positive. Concordance of combined positive and negative results between PCR and dot blot was 69%. The greater sensitivity of PCR may have accounted for 19% of specimens that were PCR positive but dot-blot negative. Unexpectedly, however, 12% of specimens were dot-blot positive but negative by PCR, and several specimens were discordant for type of HPV. Both HPV DNA tests agreed with cytology in 41% of women, and in 33% cytology was negative in the face of positive PCR and dot blot. Concordance of cytology with just PCR was 59%, and only with dot blot was 56%. Cervicography agreed with both HPV DNA tests in 41% of patients, with PCR alone in 55%, and with dot blot alone in 58%. Biopsy results did not reveal a strong correlation between histopathological criteria of HPV infection and detection of HPV DNA by either PCR or dot-blot hybridization. Thus the present study has shown that PCR is a slightly more sensitive indicator of HPV infection than dot-blot hybridization. Agreement of HPV DNA results with conventional screening tests was not strong, an observation consistent with many comparative studies by others. In conclusion, PCR is slightly more sensitive than DNA hybridization for detection of HPV, it can be used in conjunction with specimen collection by gentle lavage of the cervicovaginal epithelium, and the possibility remains that it may prove suitable as a screening test.

Adolescent↗
PubMed1990

Production and characterization of a new monoclonal antibody to colorectal carcinoma.

This study describes a new murine monoclonal antibody (MoAb) 5C1 raised against human colorectal carcinoma, which gave a differential reaction on formalin-fixed sections of the gastrointestinal tract. The MoAb 5C1 of immunoglobulin M (IgM) isotype reacted with both the cytoplasm and membrane of all normal colonic epithelia, and with all benign colonic polyps and all premalignant colonic lesions. However, there was a decreased expression of the 5C1 antigen in most cases of colonic malignancy and it was this feature that makes MoAb 5C1 unique. The distribution of the 5C1 epitope in normal gastrointestinal tract is limited to a few epithelial cells in the mid-portion of the small intestine but this distribution increased progressively down the digestive tract until it was found on greater than 90% of normal epithelial cells (in membrane and cytoplasm) of the colon. In addition, the 5C1 epitope was present on mucin secreting cells from normal organs of the gastrointestinal, reproductive and pulmonary tract and benign and malignant tissues of the colon. On Western blots, MoAb 5C1 was found to detect a heterogeneous population of molecules with molecular weights greater than 100 kDa with the strongest staining bands found between 230 and 300 kDa. MoAb 5C1 does not detect carcino-embryonic antigens (CEA), human milk fat globules (HMFG), human lymphocyte antigens (HLA) or ABO blood group antigens. The combination of its presence in mucin secreting cells and its broad molecular weight bands suggest that the antigen detected is a mucin.

Animals↗
PubMed1990

Detection of molluscum contagiosum virus DNA by in situ hybridization.

Three in situ hybridization protocols have been modified and used to comparatively examine formalin-fixed, paraffin-embedded tissue for the presence of molluscum contagiosum virus (MCV) DNA. Two cloned MCV 1 DNA fragments, MCV-1-B-D1 and MCV-1-B-F, were labelled with 32P-dCTP or digoxigenin-11-dUTP and used under conditions of high stringency to detect MCV DNA in sections of molluscum lesions. All methods were sensitive and were capable of detecting MCV after a minimum of 18 hours autoradiography (radiolabelled probes) or 3 to 18 hours (digoxigenin-labelled probes). However, one of the isotopic protocols produced less acceptable results in terms of non-specific background signals. A comparison of the DNA hybridization pattern with the underlying histopathological features of the molluscum sections revealed that there was not always a consistent association between the presence of detectable MCV DNA and cells containing the characteristic cytoplasmic inclusion bodies ("molluscum bodies") which are known to contain large numbers of virus particles. Although there is likely to be only limited scope for the application of this technique to diagnosis, it may prove useful for both retrospective and prospective epidemiological surveys. The in situ detection of MCV DNA may also be valuable for investigations into the cell biology of this imperfectly characterized virus.

Autoradiography↗
PubMed1989

Purification and biochemical characterisation of a novel breast carcinoma associated mucin-like glycoprotein defined by antibody 3E1.2.

A member of the high molecular weight glycoproteins of human milk and breast cancer was isolated from the sera, ascites and breast carcinoma tissue of patients with breast cancer using monoclonal antibody 3E1.2. The 3E1.2 defined antigen, termed mammary serum antigen (MSA) was obtained by immunoaffinity chromatography and a solid phase immuno-precipitation technique (SPIT) from serum of patients with metastatic breast cancer. MSA was found to be a high molecular weight glycoprotein with a Mr greater than 300,000 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and a native Mr approximately 1 x 10(6) by gel filtration chromatography; in accord with the published Mr of other high molecular weight glycoproteins obtained from human milk and breast cancer. A high degree of glycosylation of MSA molecule was shown by its poor staining with Coomassie blue but good staining in a PAS-silver stain. In addition, MSA contained N-acetyl neuraminic acid and N-acetyl glucosamine as indicated by its binding to wheat-germ agglutinin. The epitope defined by antibody 3E1.2 is sensitive to treatment by sodium periodate and neuraminidase, implying that both carbohydrate and sialic acid are required for binding of antibody 3E1.2. Sandwich immunoassays demonstrated that MSA+ molecules are likely to express repeated 3E1.2 defined epitopes. Furthermore, MSA was susceptible to degradation by pronase, subtilisin and proteinase K and gave a different peptide profile from that of the PAS-O glycoprotein of human milk. MSA+ molecules were found to carry epitopes for a number of other monoclonal antibodies which were reactive with the PAS-O glycoprotein. It is suggested that MSA has the same core protein as is recognised by antibody DF3 which has been used to clone the same cDNA as was cloned with antibodies HMFG-1, HMFG-2 and SM-3. However, the epitope detected by the 3E1.2 antibody is either absent or weakly expressed on human milk, human milk-fat globule membrane (HMFGM) or deglycosylated HMFGM--all of which react strongly with various anti-HMFG antibodies. The antibody 3E1.2 thus recognises a unique epitope of the high molecular weight glycoproteins of human milk and breast cancer, being found in cancer tissue, serum and ascitic fluid of patients with breast cancer but weakly expressed or absent in human milk.

Antibodies, Monoclonal↗
PubMed1989

The detection of axillary lymph node metastases from breast cancer by radiolabelled monoclonal antibodies: a prospective study.

In a prospective study to assess the accuracy of monoclonal immunoscintigraphy for the detection of axillary lymph node metastases in breast cancer, two murine monoclonal antibodies that react with human breast cancer (3E1.2 and RCC-1) were labelled with 131iodine, and the radiolabelled antibody was injected subcutaneously into the interdigital spaces of both hands of 40 patients, 36 of whom had breast cancer and the remaining four of whom had fibroadenoma (the normal, contralateral axilla was used as a control). Of the patients with breast cancer, the findings from the scintigraphy images were correlated with histopathology or cytology of the axillary lymph nodes; images were regarded as positive and hence indicative of lymph node metastases if the amount of background-subtracted radioactive count in axilla on the side of breast cancer exceeded the contralateral normal side by a ratio greater than or equal to 1.5:1.0 as assessed by computer analysis. Using this method, immunoscintigraphy had an overall sensitivity of 33% (23% with 131I-3E1.2 and 50% with 131I-RCC-1) for the detection of lymph node metastases and a specificity of 63% (67% with 131I-3E1.2 and 60% with 131I-RCC-1) with problems of non-specific uptake by presumably normal lymph nodes. The results of immunoscintigraphy obtained with 131I-RCC-1 (IgG) were superior to 131I-3E1.2 (IgM) although the accuracy of immunoscintigraphy using 131I-RCC-1 (56%) was not much better than preoperative clinical assessment (50%). However, there were cases when immunoscintigraphy using radiolabelled antibody (IgM or IgG) detected axillary lymph node metastases not suspected by clinical examination. Thus it appears that while immunoscintigraphy may be a useful adjunct to preoperative clinical assessment and is simple and safe, a major improvement in its accuracy is needed before it can replace axillary dissection and histological examination in the accurate staging of axilla in breast cancer.

Antibodies, Monoclonal↗