Whipple's Disease in an Afro-Caribbean National

Whipple''s disease is a rare multi-organ infectious disease caused by Tropheryma whipplei. It is fatal without treatment. We report on a 40-year old Afro-Jamaican man who presented with a six-month history of weight loss and diarrhoea. Investigations revealed iron deficiency anaemia and hypoalbu-minaemia. Upper gastrointestinal endoscopy revealed white patchy lesions in the duodenum. The duodenal biopsy showed broadening and thickening of the villi by a dense infiltrate of foamy histiocytes within the lamina propria and focally extending into the attached submucosa. Periodic Acid-Schiff stains were positive. Electron microscopy was confirmatory and polymerase chain reaction testing conclusively identified the organisms as T whipplei. Antibiotic treatment resulted in resolution of symptoms. Although the diagnosis of Whipple''s disease is difficult, increased awareness should lead to an increase in reported cases with the improvements in diagnostic capabilities.     

Malumfashi Endemic Diseases Research Project XXI. Some aspects of the collection of demographic data

This paper considers some of the procedures used and problems encountered in the collection of demographic data for a large-scale medical project: the Endemic Diseases Research Project at Malumfashi in northern Nigeria, 1974-1979. 43,216 people were enumerated and a subset of 26,100 were visited monthly for one year for the purpose of registration of vital events. The majority of problems encountered are relevant to similar studies in developing countries. Some difficulties cannot be avoided, but it is considered helpful to identify them. Other situations, however, deserve particular attention, such as the development of adequate on-site data-checking mechanisms, as these are areas in which future programmes could benefit from the experience of the demographic studies in Malumfashi. More effort still needs to be put into the improvement of data collection methods themselves.     

Joint effusions: MR imaging

Magnetic resonance (MR) images of the hips and knees of three healthy volunteers were reviewed and compared with images obtained from the hips of three patients with effusions. Comparison was also made with MR images obtained from two swine knees following the injections of saline in one and blood in the other. The anatomy of the knees and hips was well defined. The hip effusions were all easily recognized. MR images of the swine knees clearly demonstrated the experimentally produced joint effusions. The hip effusions and the experimentally introduced blood and saline all had long T1 and T2 values allowing easy differentiation from articular cartilage. We were unable to distinguish fresh blood from saline in the knee joints.     

Development of IgG responses to mycobacterial antigens

Recent studies link mycobacterial and human heat shock protein antigens with autoimmune diseases. Little is known about the development of antibody responses to these antigens in children. IgG responses to mycobacterial antigens were studied in children living in the UK (an environment low in mycobacteria) who had not received BCG vaccination. Age curves of IgG response to sonicates from different species of mycobacteria were similar suggesting that the greater part of the developing IgG response is to the common antigens shared by all mycobacteria. The major part of the IgG response was to carbohydrate antigens: lipoarabinomannan is a mycobacterial cell wall carbohydrate and was confirmed as a major immunodominant antigen. Infants showed a marked early response to the mycobacterial 65 kilodalton (kDa) and 70 kDa heat shock proteins, but not to the human 65 kDa heat shock protein. The early IgG response to heat shock proteins may reflect cross reactivity to proteins released by a wide variety of bacteria (possibly from breakdown in the gut) or recognition of other immunodominant antigens with high levels of cross reactivity to self.     

Influence of vertebral fat content on quantitative CT density

Single- and dual-energy (85 and 130 kVp) computed tomographic (CT) measurements of bone density were made in 74 lumbar (L-3) vertebral specimens. Single-energy CT densities at 130 kVp consistently underestimated actual ash density by about 25 mg/cm3 in men and 40 mg/cm3 in women. CT densities overestimated age changes by 73% in women and 26% in men. These errors of the single-energy CT approach seemed due to increased marrow fat caused by age. At 130 kVp, there was a large decrease in apparent bone density (13 mg/cm3) for each increase of 100 mg/cm3 in fat content, but the decrease was lower at 85 kVp (11 mg/cm3), suggesting the use of lower energies for quantitative CT. In the vertebrae from the younger subjects (up to age 69), the relative error was 20%-31%, but in the oldest group it amounted to 31%-45%. The 95% confidence interval for an individual determination was +/- 38 mg/cm3. Dual-energy CT greatly reduced the above errors. Ash density was predicted with only a small accuracy error (7 mg/cm3) using a postprocessing dual-energy calculation, but the prediction error was 19 mg/cm3 for determinations at 130 kVp. The large uncertainty in the fat content of marrow (+/- 110 mg/cm3) and the variability in distribution of fat make dual-energy approaches necessary for accurate determinations of vertebral mineral density.