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The relationship between antigenic variation, cytoadherence, rosette formation, and the pathogenesis of malaria has led to great interest in the diversity of these properties in Plasmodium falciparum isolates from different communities. In this study, we extend previous investigations by delineating the spectrum of agglutinating phenotypes, adherence to C32 melanoma cells, human umbilical vein endothelial cells (HUVEC), CD36, and intracellular adhesion molecule-1 (ICAM-1), and rosette-forming ability of a group of 20 P. falciparum isolates from Papua New Guinean children. Agglutination phenotypes were determined by using both the children's convalescent serum and a panel of adult immune sera. The wide range of variant antigenic types in the community was demonstrated by the failure of the agglutination assays to identify any two isolates with the same agglutinating phenotype in this, the largest study of its kind. Comparison of agglutination profiles from fresh and cryopreserved isolates demonstrated the general acceptability of cryopreservation before testing, but cautioned that some isolates may undergo selection and phenotypic change during the process. Nineteen isolates were able to bind to at least one of the four ligands studied and showed marked variation in both avidity and specificity of binding. The purified proteins ICAM-1 and CD36 proved to be the most useful assay ligands for investigating field isolates, with 18 isolates binding to at least one protein and 14 to both. No correlation was found between the binding of isolates to any two ligands nor between the binding of a standardized inoculum and the level of the patient's presenting parasitemia. All isolates from the study group were found to form rosettes (at a mean rate of 14.6% of cultured trophozoites involved in rosettes). A lack of correlation between rosette formation and CD36 binding suggests that the previously reported role of CD36 as a rosette formation receptor may not be important for isolates from Papua New Guinea.

We prospectively evaluated autonomic nervous system function in 17 consecutive ambulant patients with HIV infection [mean age (S.D.) 34.5 (5.5) years] and 17 controls matched for sex and age [31.2 (7.4) years]. A questionnaire was administered, and neurological examination and standard bedside autonomic function tests were performed. Eleven of 17 HIV-infected individuals (64.7%) had symptoms suggestive of autonomic dysfunction, particularly urogenital problems. Thirteen of 17 (76.5%) had autonomic neuropathy (one or more abnormal tests), including nine of 11 symptomatic individuals. Only two controls had any autonomic symptoms, and all had normal tests. Autonomic dysfunction is common in those with HIV infection and AIDS.

A total of 212 adult patients with infective diarrhoea and 27 with inflammatory bowel disease (IBD), admitted consecutively to an infectious disease unit, were studied in order to determine whether clinical features and laboratory measurements performed on admission identified cases of IBD. Long-standing diarrhoea, blood in the faeces, anaemia, leucocytosis, thrombocytosis, raised ESR and a reduced concentration of serum albumin were more common in patients with IBD (P less than 0.05). The most striking difference was in the platelet count with 59% patients with IBD and 1.6% patients with infective diarrhoea having platelet counts greater than 450 x 10(9)/l. A raised platelet count in a patient admitted to hospital with 'acute gastro-enteritis' suggests IBD.

We investigated the effect of hydrocortisone on mortality and complications in chloramphenicol-treated severe typhoid fever (STF) in Goroka, Papua New Guinea. Of 374 culture-positive patients, 146 formed a retrospective comparison group, of whom 41 had STF. Of 228 patients in the intervention group, 58 had STF. Patients without STF had low mortality (2.5%) with standard treatment. In the intervention group, hydrocortisone was used in two dosage schedules, 100 mg for 12 doses (23 patients) and 400 mg for 12 doses (23 patients). There was no difference in mortality between steroid-treated and comparison STF patients (44.8% versus 43.9%) or in complications, and we conclude that moderate doses of steroids are not beneficial in severe typhoid fever.

Five hundred and ninety-four patients were consecutively admitted to an infectious disease unit over a 2-year period with a referral diagnosis of acute gastroenteritis or food poisoning. In 175 (29%) patients, gastrointestinal symptoms were associated with a condition other than gastrointestinal infection. Non-infective gastrointestinal disease was present in 90 patients, systemic infection in 50 and systemic disease in 35. Four illustrative case histories are presented to emphasize the need for a high index of suspicion if diseases such as malaria, septicaemia or appendicitis are not to be missed.

We describe a case of group G streptococcal septicaemia complicated by sterile polyarthritis and pericarditis. We suggest that this organism may cause a 'reactive arthritis' type of illness, and that this is in keeping with known properties of the organism. We note that our patient's clinical features fit the modified Jones criteria for the diagnosis of rheumatic fever.