Heavy Trichuris infection and amoebic dysentery in Orang Asli children. A comparison of the two diseases

Children with heavy Trichuris infestation were compared with paediatric amoebic dysentery patients and normal children. Heavy Trichuris infestation was diagnosed by visualization of worms on anoscopy.Patients with heavy Trichuris infection had a longer duration of disease, more frequent hospitalization and a higher rate of rectal prolapse than did patients with amoebiasis. Five Trichuris children also had clubbing. Trichuris patients had lower mean haematrocrits (27%) and serum albumin (3·3 gm%) than did patients with amoebiasis (32% and 3·7 gm% respectively). Coinfection with Shigella and Salmonella was significantly increased in patients with heavy Trichuris infection compared to both amoebic and control group children. Trichuris patients were infected with Entamoeba histolytica more frequently (46%) than normal children. Heavy Trichuris infection is the probable cause of symptoms and signs seen in these patients.     

Predisposition to Trichuris trichiura infection in humans

The study examines the distribution of Trichuris trichiura infection in a village community in St Lucia, West Indies. The infection intensity of the same age-stratified population was assessed (by drug expelled worm burden and faecal egg count) at the initiation of the study, and after 17 months of reinfection following treatment. The frequency distribution of worm numbers per person was similar at both periods of sampling. There was a significant correlation between the initial infection intensity of an individual, and the intensity acquired by the same individual following the 17 month period of reinfection. This relationship was observed in a broad range of host age classes. The study provides firm evidence that individuals are predisposed to heavy (or light) T. trichiura infection.     

Characterization of the complete mitochondrial genomes of two whipworms Trichuris ovis and Trichuris discolor (Nematoda: Trichuridae)

For many years, whipworms (Trichuris spp.) have been described with a relatively narrow range of both morphological and biometrical features. Moreover, there has been insufficient discrimination between congeners (or closely related species). In the present study, we determined the complete mitochondrial (mt) genomes of two whipworms Trichuris ovis and Trichuris discolor, compared them and then tested the hypothesis that T. ovis and T. discolor are distinct species by phylogenetic analyses using Bayesian inference, maximum likelihood and maximum parsimony) based on the deduced amino acid sequences of the mt protein-coding genes. The complete mt genomes of T. ovis and T. discolor were 13,946 bp and 13,904 bp in size, respectively. Both mt genomes are circular, and consist of 37 genes, including 13 genes coding for proteins, 2 genes for rRNA, and 22 genes for tRNA. The gene content and arrangement are identical to that of human and pig whipworms Trichuris trichiura and Trichuris suis. Taken together, these analyses showed genetic distinctiveness and strongly supported the recent proposal that T. ovis and T. discolor are distinct species using nuclear ribosomal DNA and a portion of the mtDNA sequence dataset. The availability of the complete mtDNA sequences of T. ovis and T. discolor provides novel genetic markers for studying the population genetics, diagnostics and molecular epidemiology of T. ovis and T. discolor.     

Growth suppression of transplantable tumors in experimental animals given soya proteins

The development of a malignant process and antitumor treatment leads to the occurrence of a variety of complications. It is expedient to use biological regulators of natural origin to eliminate the side effect of chemical drugs and to improve the outcomes of antitumor therapy. The antitumor effect of soya proteins and their influence on antibody formation and oxidative processes in the sera of tumor-bearing animals were investigated. Soya proteins are shown to retard the development of a tumorous process, modulate the therapeutic effect of 5-fluorouracil, enhance antibody formation, and normalize serum oxidative processes.     

Overnight dexamethasone suppression test: a reliable screen for Cushing's syndrome in the obese

OBJECTIVE: Reevaluation of the validity of the 1-mg overnight dexamethasone suppression test (ODST) as a screening test for Cushing's syndrome in obese patients. RESEARCH METHODS AND PROCEDURES: Eighty-six obese patients (body mass index, 30 to 53 kg/m(2)) that were referred to a general endocrine outpatient clinic for evaluation of simple obesity, diabetes mellitus, hypertension, polycystic ovary disease, or pituitary tumor. One milligram dexamethasone was administered orally at 11:00 PM, and serum cortisol levels were measured the following morning between 8:00 AM and 9:00 AM. Suppression of serum cortisol to <80 nM (3 micro g/dL) was chosen as the cut-off point for normal suppression. Patients with serum cortisol levels > or =80 nM were evaluated for Cushing's syndrome. RESULTS: Suppression of morning cortisol levels to <80 nM occurred in 79 of the 86 obese patients. Seven patients had serum cortisol levels higher than 80 nM; five were eventually diagnosed with Cushing's syndrome and two were considered false positive results in view of normal 24-hour free urinary cortisol and normal suppression on a low dose dexamethasone suppression test (0.5 mg of dexamethasone every 6 hours for 2 days). We found a false positive rate of 2.3% for the ODST using a cut-off serum cortisol of 80 nM. DISCUSSION: The ODST is a valid screening test for Cushing's syndrome in the obese population. The false positive rate was 2.3%, even when using a strict cut-off serum cortisol of 80 nM. Abnormal cortisol suppression in obese patients should be investigated and not be considered false positive results.     

Epidemiological aspects of Trichuris and trichuriasis in Caribbean communities

The review argues for a reappraisal of the health significance of the human whipworm, Trichuris trichiura. Infections with this geohelminth are at least as prevalent as Ascaris lumbricoides in many localities, and are associated with significant morbidity. Infection may result in severe trichuriasis syndrome or, more frequently, in a chronic colitis associated with growth stunting. Under-reporting of the chronic manifestations of disease has resulted in a gross under-estimation of the health impact of trichuriasis. Furthermore, estimation of the population dynamical parameters of T. trichiura transmission suggests that whipworm infections are intrinsically more resistant to control than those of other common geohelminths. A major determinant of the transmission dynamics and morbidity characteristics of this helminthiasis is the aggregation of worm burdens in certain predisposed individuals and age groups. It is suggested that improved understanding of the factors generating this distribution of infection intensity is a pre-requisite for effective control of both infection and morbidity.