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Biomedical subjects

C H Cameron

Publications and source records attributed to C H Cameron.

At least 37 records · Page 2Linked to original sources

The ultrastructural features of malakoplakia.

The ultrastructural features of a case of disseminated malakoplakia are described and compared with available published cases. Generally macrophages were involved (although characteristic inclusions were seen in association with some plasma cells) and contained three types of cellular inclusions. These were (1) the phagolysosomes (2) and intermediate structure sharing features of the phagolysosome and the Michaelis-Gutmann (MG) body and (3) the MG body. All inclusions were delineated by unit membranes and their matrices (except those of large MG bodies) composed of membranous whorls and loops. It is suggested that these inclusions represent stages in the development of the MG body. Septate junctional complexes were observed between phagolysosomes and small MG bodies. These complexes may represent either a mechanism of organelle fusion or an abnormality of molecular organisation of the limiting unit membrane.

Cytoplasm↗

An inexpensive, portable, battery-operated photometer for the reading of ELISA tests in microtitration plates.

We described an inexpensive, portable, battery-operated photometer which can read the enzyme-linked immunosorbent assay in 96-well microtitre trays. An example is given of its use to measure IgG antibody to human collagen type II in a serum sample from a rheumatoid arthritis patient known to have a high titre of antibody to cartilage by immunofluorescence. When the same samples were read first with the portable photometer and then in a spectrophotometer (Unicam SP 1800), the accuracy of the two devices was comparable, but the readings were obtained far more quickly in the photometer.

Adolescent↗

A sensitive immunoradiometric assay for the detection of hepatitis B surface antigen.

A solid-phase immunoradiometric assay for hepatitis B surface antigen is described which has been in use since 1971. Initially it was used for reference laboratory work, but from 1974 it has also been used for screening blood and blood products. Methods for the production of reagents and their use in blood transfusion and reference work are outlined.

Blood Donors↗

A sensitive single reverse passive haemagglutination test for detecting both HBsAg and anti-HBs.

A trial of a modified reverse passive haemagglutination test for HBsAg using a 0.1% cell suspension instead of the recommended 1% showed an approximately eight-fold increase in detection sensitivity. The test can be performed within 30 minutes and lends itself to mass screening techniques. Confirmation tests can be done using the 0.1% method. In addition, the same serological plates and cells used for HBsAg screening can then be used to screen for high-titre anti-HBs. This makes the overall screening for both HBsAg and high-titre anti-HBs donors cheap and convenient.

Antibodies, Viral↗

Barium granuloma of the transverse colon.

A case of barium sulphate granuloma of the transverse colon following gunshot wounds to the abdomen has been described. Scanning electron microscopy with electron probe microanalysis was used to confirm the presence of barium sulphate and the absence of lead or other elements related to the gunshot wounds.

Abdominal Injuries↗

A comparison of different methods of screening blood donations for HBsAg.

In a retrospective comparison between countermigration immunoelectrophoresis (CIEP) and reverse passive haemagglutination (RPHA) for screening 260,500 blood donations, the latter's 10-fold increase in sensitivity resulted in 36% more HBsAg detections. In a prospective comparison between RPHA and radioimmunoassay (RIA) the latter's 40-fold increase in sensitivity over RPHA resulted in 11% more detections than RPHA in 27,094 new donors. One in 500 new donors was HBsAg-positive by RPHA, compared with 1 in 11,000 established donors who had donated and been tested previously. Acute hepatitis B infections, though uncommon, accounted for a greater proportion of the HBsAg-positive found in "established" rather than new donors. Reported post-transfusion hepatitis cases have declined following the introduction of screening tests in 1971. The feasibility of RIA testing at a transfusion centre supplied simply with the two basic RIA reagents has been demonstrated.

Blood Donors↗

Hepatitis B surface antigenaemia in Kenyans with chronic liver disease.

Fifty Kenyan patients with chronic liver disease or hepatocellular carcinoma were tested for hepatitis B surface antigenaemia by radioimmunoassay. The hepatitis B surface antigen was detected in 77% of the patients with chronic persistent or chronic aggressive hepatitis, or cirrhosis confirmed by liver biopsy, compared with 15% in a control group. All six patients with hepatocellular carcinoma had detectable hepatitis B surface antigen or antibody. 50% of the controls had hepatitis B surface antibody in their plasma detectable by haemagglutination. Auto-immune associated liver disease appeared infrequent. The possibility that the hepatitis B virus is an important cause of cirrhosis in Kenya is discussed.

Cell Membrane↗

The preparation of human articular cartilage for scanning electron microscopy.

This paper compares sixteen preparative techniques thought to be of advantage in the study by scanning electron microscopy (SEM) of human articular cartilage surfaces. The adequacy of surface preservation obtained with the techniques, was judged subjectively, first, by the reproducubility of secondary electron images of normal cartilage, and second, by comparing the results with those obtained by reflected light microscopy of the fresh unfixed cartilage surface over a magnification range of X20- X240. Adequate surface preservation was confirmed when cartilage surfaces had been dehydrated through ethanol to propylene oxide and vacuum dried; dehydrated through amyl acetate and quenched in Freon before freeze-drying; dehydrated and passed through amyl acetate at low temperature before freeze drying. Valuable information can be obtained from different specimens by varying the technique of preparation. At different ages, different surface features are best preserved. In a systematic study it has been found essential to adopt a uniform preparative method and to control the results by reflected light microscopy. Even with the most perfect preparation, the surface appearances cannot be identical with those that function under load in vivo.

Adolescent↗