Trypanosomiasis-induced infertility in dromedary (Camelus dromedarius) bulls: changes in plasma steroids concentration and semen characteristics

The effect of Trypanosomiasis on concentrations of plasma steroids and semen characteristics was studied in 24 dromedary bulls. Based upon the parasitological and serological diagnosis, 18 bulls were found infected with Trypanosoma evansi (Group 2) and six were found to be free from infection and served as controls (Group 1). The infected animals exhibited signs of anaemia indicated by the decrease of packed cell volume (PCV) and haemoglobin concentration (Hb), pale mucus membranes, weight loss, lethargy, weakness and dullness. However, five animals (27.8%) of the infected group revealed elevated rectal temperatures and three animals (16.7%) revealed testicular degeneration upon palpation of their scrotal contents. Concentrations of plasma oestradiol-17beta (86.5 +/- 8.6 pg/ml versus 232.5 +/- 74.4 pg/ml) and testosterone (4.8 +/- 0.7 ng/ml versus 2.7 +/- 1.5 ng/ml) were significantly different (P < 0.05) between the control and infected bulls. Evaluation of the semen collected by electroejaculation and evaluated by a computerized cell motion analyzer revealed normal semen characteristics in the control animals compared to deteriorated ones in the infected bulls. There were highly significant (P < 0.01) decreases in sperm count (12.2 +/- 1.3/ml versus 6.5 +/- 4.9 x 10(6)/ml), motility percentage (68.2 +/- 6.7% versus 27.4 +/-15.6%), percentage of live spermatozoa (73.2 +/- 8.3% versus 35.8 +/- 8.2%) and increases in percentage of morphological abnormalities (3.3 +/- 0.6% versus 15.9 +/- 1.0%) in the infected group. An examination of the plasma hormonal profiles and semen characteristics in the infected bulls indicated that altered Sertoli cell function due to formation of immune complexes in four bulls (Group 2A), pituitary dysfunction in six bulls (Group 2B), testicular degeneration in three bulls (Group 2C) and finally trypanotolerancy in five bulls (Group 2D) are possible factors responsible for poor semen characteristics and infertility induced by T. evansi infection in dromedary bulls.

Biochemical profiles in Friesian cattle naturally infected with Theileria annulata in Saudi Arabia

The biochemical parameters were studied in adult and young Friesian cattle naturally infected with Theileria annulatta in the Qassim Region, Saudi Arabia. Forty-three clinical cases of tropical theileriosis were studied, together with 40 clinically healthy Friesian cattle. Cattle clinically infected with T. annulata had significantly lower serum total protein, albumin, globulin, creatinine, calcium, phosphorus, magnesium, potassium, iron and copper concentrations and significantly higher AST activity and bilirubin concentration than the healthy cattle.

Evaluation of laboratory techniques for differentiation between Entamoeba histolytica and Entamoeba dispar

Incorporation of clinical, epidemiological and serological parameters to the studies of Entamoeba histolytica resulted in the conclusion that species complex comprising two morphologically identical amoeba were implicated with the disease. The two organisms are E. histolytica and E. dispar. The former is a pathogen and responsible for invasive amoebiasis while the later is a gut commensal. Clearly accurate diagnostic tools are required to distinguish the two species. The use of a stool ELISA has been shown to be useful. A monoclonal enzyme linked immunosorbent assay based kit to detect antigen of E.histolytica only in stool was evaluated in comparison to the results of the microscopical examination of the stools and that of enzyme linked immunosorbent assay used to detect the anti- E. histolytica IgG in serum. This study demonstrated that E. dispar is prevalent in the community and offers promise for E. histolytica monoclonal enzyme immunoassay for the qualitative and semiquantitative determination of sensu lato antigen in stool as a sensitive tool for detection and distinction of E. histolytica from E. dispar infections.

Streptozotocin may provide protection against subsequent oxidative stress of endotoxin or streptozotocin in rats

Endotoxin lipopolysaccharide (LPS) and streptozotocin-induced diabetes are known to cause oxidative stress in vivo. There is some evidence that a sublethal dose of LPS provides protection against subsequent oxidative stress. Because of its wide use as a diabetogenic agent, this study was undertaken to determine if streptozotocin can likewise provide a protective effect against further oxidative stress in rats. Female Sprague-Dawley rats were given streptozotocin (50 mg/kg intraperitoneally once) prior to exposure to either bacterial endotoxin from Salmonella abortus equii (5 mg/kg intraperitoneally) or three additional daily doses of streptozotocin (50 mg/kg intraperitoneally). One week after LPS or streptozotocin treatments, oxidative stress was determined by measuring changes in antioxidant activity (glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, glutathione S-transferase, and gamma-glutamyltranspeptidase) and in concentrations of glutathione, nitrite, and thiobarbituric acid reactants in liver, kidney, intestine, and spleen. High levels of some antioxidants in the LPS-control and streptozotocin-control rats, in contrast to normal levels found in diabetes + LPS and multidose-streptozotocin rats, suggest that streptozotocin, like LPS, may confer a protective effect against subsequent oxidative stress.

Excess female mortality in rural Somalia--is inequality in the household a risk factor?

Gender differences in mortality risks in rural Somali communities were studied to assess their relation to literacy, marital status and family economy between January 1987 and December 1989. In all, 6947 person-years form the basis for the demographic analysis and estimations of mortality rates and survival. Both sexes showed similar mortality risks in infancy and early childhood, but females demonstrated a greater risk of dying during their reproductive life than males. Respiratory symptoms, diarrhoea, fever and jaundice dominated the symptoms prior to death Illiteracy in women considerably increased the risk of dying from 15 years and onwards particularly when living with literate men. The life expectancy from 15 years was 58 for a literate male but only 42 years for an illiterate woman living with a literate head of household. Multivariate analyses showed after adjustment for marital status and literacy that an excess female mortality from 15 years, but especially from 45 years, was associated to a household situation, where the woman did not subside on farming but on other, mainly commercial, activities. This vulnerability of females was associated to the recession of the economy in the pre-war situation in Somalia, a backlash hitting women trying to earn their living. To conclude, gender differences in a number of factors in the household-literacy, marital status and especially source of income-were disadvantageous for the women, increasing the mortality risk in this setting.

Hepatobiliary excretion of cysteinyl leukotrienes in three experimental models of acute hepatic injury

The acute phase response to chemically-induced organ damage involves inflammation and the production of leukotrienes. The liver ordinarily takes up, metabolizes and excretes into bile cysteinyl leukotrienes, but the effect of hepatic injury on these processes is unknown. The hepatic uptake and biliary excretion of LTC4 was studied in male Sprague-Dawley rats after exposure to either streptozotocin (45 mg/kg iv 30 days before experimentation), estradiol-17 beta-valerate (1 mg/kg sc once a week for 3 weeks) or lipopolysaccharide/D-galactosamine (33 micrograms/ kg ip; 300 mg/kg ip at 6 h and 3 h, respectively, before experimentation). Acute liver injury is produced by these treatment paradigms. Glucose concentrations and activities of several marker enzymes in plasma were measured to demonstrate hepatic injury. Biliary excretion of 3H-LTC4 was similar to normal control rats in the three types of acute liver injury. Bile flow rates after 3H-LTC4 injection were reduced in lipopolysaccharide-pretreated rats and increased in estradiol-treated animals. Total biliary excretion of leukotrienes was not altered in any disease group. Thus, these models of acute hepatic injury do not appear to influence the hepatobiliary clearance of leukotrienes.

Child mortality in a collapsing African society

A cohort study of mortality among under-5-year-olds was carried out in two Somali villages in 1987-89, a period of economic and political collapse in the rural parts of the country. Analysed was the relative importance of the social characteristics for under-5-year-old mortality against a background of deteriorating political and economic conditions. Mortality increased among under-5-year-olds from 1987 (211 per 1000) to 1988 (323 per 1000) to 1989 (414 per 1000). The mortality risk was more pronounced for boys than girls and was more so for infants than children aged 1-4 years. The major signs prior to death were respiratory infections, diarrhoeal diseases, fever/malaria and tetanus in the neonatal period. Over the 3-year study period mortality rates for diarrhoeal diseases increased significantly, while those for respiratory infections and diseases preventable by immunization increased more slowly. The increasing trend in under-5-year-old mortality was more pronounced in instances when the mother derived her major income from sources other than farming and in larger households.

Diarrhoea among children in rural Somalia. Maternal perceptions, management and mortality

Diarrhoea was the second most common symptom of disease in a longitudinal study of 431 children under 5 years of age in rural Somalia. Most mothers perceived diarrhoea as a condition in which oral rehydration therapy (ORT) and feeding were logical parts of its management. During 1 year of observation, ORT was used in the household in one-third of the episodes of diarrhoea, mostly by non-farming, young and literate mothers. Infants were treated more often than older children, as were also children in smaller households. In a 3-year demographic surveillance in the same area (1219 person years), the under-5 mortality from diarrhoea in children of literature and illiterate mothers was 43 per 1000 (95% CI 0-84) and 93 per 1000 (95% CI 60-101), respectively. The findings suggest that the use of ORT is associated with a mother's ability to allocate time to health care and her general position in the household.

Immunity to Toxocara vitulorum repeated infections in a rabbit model

Eleven rabbits were infected with 10 embryonated eggs of Toxocara vitulorum per g body weight on Days 0, 35 and 72. Embryonated eggs and larvae were enumerated in feces on Days 1-3 after each infection. Two rabbits were killed and larvae were enumerated in small intestine, liver, lungs, skeletal muscles, heart, kidney, brain, eye, uterus, and mammary glands on Days 5, 15, 30, 65 and 101. Serum was obtained on Days 0, 5, 15, 30, 42, 50, 65, 78, 86 and 101 to perform enzyme-linked immunosorbent assays (ELISAs) and Western blots against an extract of embryonated eggs. Between 4 and 10% of the administered parasites, almost all embryonated eggs, were found in the feces after the first or second infection, but 32% (27% of them larvae) after the third. Yields of tissue parasites were 4.1% of the administered dose on Day 5, 2% on Day 15, and 0.8% on Day 30 of the first infection, 0.1% on Day 30 of the second infection, and 0.06% on Day 30 of the third. Larvae were found only in liver, lungs and muscle, including heart. Larva content declined steadily in liver and lungs from Day 5 to 30 of the first infection, was absent in the liver at Day 30 of the second, and in both organs at Day 30 of the third. Muscle larva content increased from Day 15 to 30 of the first infection, and persisted throughout the third infection. Production of IgM antibody was minimal, IgG and the sum of IgMGA antibodies increased slightly or moderately after the first and second infections, but dramatically after the third. Western blots revealed the first antigens (12) by Day 15 of the first infection. Their total number increased with time and number of infections, but some antigens disappeared, whereas new antigens appeared in the course of the observations. Four antigens (32,500-41,000 mol.wt.) may be related to protection. Comparison of the Western blot patterns of two rabbits showed differences in the antigens, recognizable for each rabbit.

Comparison of isolates and species of Toxocara and Toxascaris by biosynthetic labelling of somatic and ES proteins from infective larvae

Infective-stage larvae of three different isolates of Toxocara canis were intrinsically ([35S]methionine) labelled in culture, to determine the presence of similarities or differences in the somatic and ES antigens expressed between larvae derived from different hosts and different geographical regions. Two other closely related ascaridids, Toxascaris leonina which infects cats and dogs, and Toxocara vitulorum (Neoascaris vitulorum) which infects cattle, were also compared to T. canis larvae by this method. Overall comparisons were made by 1- and 2-dimensional electrophoresis, while immunological cross-reactivities between the different species were analysed by radio-immunoprecipitation. Our results show that extensive physicochemical characteristics are shared between T. canis isolates, both from different hosts and different geographical locations. A substantial overlap was revealed when T. canis and T. vitulorum antigens were compared, whereas Toxascaris was found to produce a distinct antigen profile: this result was independent of whether methionine- or Iodogen-labelled products were being considered. Antigen recognition by polyclonal antibodies raised to all three species and to the cat ascaridid Toxocara cati, revealed considerable cross-reactivities. The cross-reactions were especially prominent between the Toxocara species, a fact further substantiated when reactivity of T. canis ES-specific monoclonal antibodies were tested against T. leonina and T. vitulorum antigens. The ES antigens of T. leonina were not recognized by the T. canis monoclonals, whereas the majority of these antibodies precipitated antigens of T. vitulorum. One which did not react with T. vitulorum was monoclonal antibody Tcn 2, indicating its species-specific reactivity and therefore its potential for the specific diagnosis of human toxocariasis.

Biology and pathophysiology of Toxocara vitulorum infections in a rabbit model

Ten female New Zealand rabbits were infected via stomach intubation with eggs of Toxocara vitulorum at a dosage of 10 embryonated eggs per gram of body weight on Days 0, 35 and 72. Ten or 4% of the administered parasites passed in the feces during the 3 days following the first or second infection, but 32% after the third infection. Many larvae were passed in the third infection, but not in the first or second. Tissue parasite yields were 4.1% on Day 5, 2% on Day 15, 0.8% on Day 30, 0.1% on Day 65 and 0.06% on Day 101. Five hundred and ninety-three larvae were recovered from liver, 243 from lungs and 0 from muscles on Day 5; 282 from liver, 138 from lungs and 21 from muscles on Day 15; 151 from liver, 21 from lungs and 50 from muscles on Day 30; 0 from liver, 26 from lungs and 15 from muscles on Day 65; 0 from liver, 0 from lungs and 9 from muscles on Day 101. No larvae were found in other tissues. The size of the muscle larvae at 30, 65 and 101 days indicated that the parasites did not develop beyond the infective stage and suggested that they were probably hypobiotic organisms. Erythrocytes, packed cell volume and monocytes decreased, but eosinophils and basophils increased, after each infection. Serum enzyme levels indicated that liver damage occurred only after the first infection, but muscle injury occurred after each infection and was increasingly more precocious after each infection.

Regional cerebral blood flow in acute stroke: preliminary experience with the 133 xenon inhalation method

The 133 Xenon inhalation method of measuring regional cerebral blood flow was applied in serial studies comprising 100 measurements in 57 cases of acute hemiparesis and hemiplegia presumed due to arterial occlusion. Satisfactory data for analysis were obtained in over 95% of the cases studied. Significant flow reductions in the ischemic hemisphere were demonstrated in the cases with more severe clinical disability. This study demonstrates the feasibility of applying this method for serial regional cerebral blood flow measurements in most cases of acute stroke. The expected clinical usefulness and limitations of the method are discussed.