ROS- and Radiation Source-Dependent Modulation of Leukocyte Adhesion to Primary Microvascular Endothelial Cells.

Anti-inflammatory effects of low-dose irradiation often follow a non-linear dose-effect relationship. These characteristics were also described for the modulation of leukocyte adhesion to endothelial cells. Previous results further revealed a contribution of reactive oxygen species (ROS) and anti-oxidative factors to a reduced leukocyte adhesion. Here, we evaluated the expression of anti-oxidative enzymes and the transcription factor Nrf2 (Nuclear factor-erythroid-2-related factor 2), intracellular ROS content, and leukocyte adhesion in primary human microvascular endothelial cells (HMVEC) upon low-dose irradiation under physiological laminar shear stress or static conditions after irradiation with X-ray or Carbon (C)-ions (0-2 Gy). Laminar conditions contributed to increased mRNA expression of anti-oxidative factors and reduced ROS in HMVEC following a 0.1 Gy X-ray and 0.5 Gy C-ion exposure, corresponding to reduced leukocyte adhesion and expression of adhesion molecules. By contrast, mRNA expression of anti-oxidative markers and adhesion molecules, ROS, and leukocyte adhesion were not altered by irradiation under static conditions. In conclusion, irradiation of endothelial cells with low doses under physiological laminar conditions modulates the mRNA expression of key factors of the anti-oxidative system, the intracellular ROS contents of which contribute at least in part to leucocyte adhesion, dependent on the radiation source.

Malnutrition in Healthy Individuals Results in Increased Mixed Cytokine Profiles, Altered Neutrophil Subsets and Function.

Malnutrition is commonly associated with increased infectious disease susceptibility and severity. Whereas malnutrition might enhance the incidence of disease as well as its severity, active infection can in turn exacerbate malnutrition. Therefore, in a malnourished individual suffering from a severe infection, it is not possible to determine the contribution of the pre-existing malnutrition and/or the infection itself to increased disease severity. In the current study we focussed on two groups of malnourished, but otherwise healthy individuals: moderately malnourished (BMI: 18.4-16.5) and severely malnourished (BMI <16.5) and compared several immune parameters with those of individuals with a normal BMI (≥18.5). Our results show a similar haematological profile in all three groups, as well as a similar ratio of CD4+ and CD8+ T cells. We found significant correlations between low BMI and increased levels of T helper (Th) 1 (Interferon (IFN)-γ, (interleukin (IL)-2, IL-12), Th2 (IL-4, IL-5, IL-13), as well as IL-10, IL-33 and tumor necrosis factor-α, but not IL-8 or C reactive protein. The activities of arginase, an enzyme associated with immunosuppression, were similar in plasma, peripheral blood mononuclear cells (PBMC) and neutrophils from all groups and no differences in the expression levels of CD3ζ, a marker of T cell activation, were observed in CD4+ and CD8+T cells. Furthermore, whereas the capacity of neutrophils from the malnourished groups to phagocytose particles was not impaired, their capacity to produce reactive oxygen species was impaired. Finally we evaluated the frequency of a subpopulation of low-density neutrophils and show that they are significantly increased in the malnourished individuals. These differences were more pronounced in the severely malnourished group. In summary, our results show that even in the absence of apparent infections, healthy malnourished individuals display dysfunctional immune responses that might contribute to increased susceptibility and severity to infectious diseases.

Tissue engineering approach to repair abdominal wall defects using cell-seeded bovine tunica vaginalis in a rabbit model.

The aim of this study was to engineer skeletal muscle tissue for repair abdominal wall defects. Myoblast were seeded onto the scaffolds and cultivated in vitro for 5 days. Full thickness abdominal wall defects (3 x 4 cm) were created in 18 male New Zealand white rabbits and randomly divided into two equal groups. The defects of the first group were repaired with myoblast-seeded-bovine tunica vaginalis whereas the second group repaired with non-seeded-bovine tunica vaginalis and function as a control. Three animals were sacrificed at 7th, 14th, and 30th days of post-implantation from each group and the explanted specimens were subjected to macroscopic and microscopic analysis. In every case, seeded scaffolds have better deposition of newly formed collagen with neo-vascularisation than control group. Interestingly, multinucleated myotubes and myofibers were only detected in cell-seeded group. This study demonstrated that myoblast-seeded-bovine tunica vaginalis can be used as an effective scaffold to repair severe and large abdominal wall defects with regeneration of skeletal muscle tissue.

Gastrointestinal nematodes in dogs from Debre Zeit, Ethiopia.

The study was conducted during the period between January 2005 and June 2006 to determine the frequency of gastrointestinal (GI) nematode infections of dogs in and around Debre Zeit, using qualitative and quantitative coprological (N = 100) and postmortem examinations (N = 20). By coproscopy 51% dogs were positive for different types of nematodal eggs, out of which 23.5% were with mixed infections. On necropsy 95% animals were found positive for adult parasites, of which 31.6% were showing more than one species of adult nematodes. The coproscopical examination revealed 32% infection with Ancylostoma caninum followed by Toxocara canis (21%), Spirocerca lupi (7%) and Trichuris vulpis (3%), while postmortem examination showed 70, 45, 23.5 and 5% infection, respectively. The study further indicated significant difference (P < 0.05) in overall frequency of GI nematode infections among different age groups but no difference (P > 0.05) between sexes.

Characterization of a complex restriction-modification system detected in Staphylococcus aureus and Streptococcus agalactiae strains isolated from infections of domestic animals.

Characterization of classic type II restriction-modification systems (RMS) (restriction endonucleases and modification methyltransferases) was carried out in isolates of Staphylococcus aureus and Streptococcus agalactiae obtained from clinical material. Among the 100 isolates of S. aureus two different RMS type II were detected. The first was expressed in isolates 32 and 33 (Sau32 I and Sau33 I); the targeting sequence was determined as 5'-GGN CC-3' (Sau96 I isoschizomer). The second was found in isolates no. 90, 93, 96*, and 98 (Sau90 I, Sau93 I, Sau96* I, Sau98 I) and enzymes recognized sequence 5'-CTY RAG-3' (SmlI isoschizomer). Analysis of 40 isolates of S. agalactiae revealed only one RMS; it was detected in two isolates (no. 16 and 23; Sag16 I and Sag23 I). Restriction endonuclease expressed by these isolates cleaved DNA in sequence 5'-CTG CA/G-3' (PstI isoschizomer). In RMS-positive S. aureus and S. agalactiae isolates plasmid DNA capable of replication in Escherichia coli and Bacillus subtilis was also detected and isolated.

The efficacy of oxamniquine in selective population chemotherapy in Ethiopia.

Oxamniquine, at 40 mg/kg body weight, was used in a pilot schistosomiasis control programme in an endemic community in Ethiopia. After mass screening of the population using Kato's thick smear method, 1556 positive patients were treated in divided doses over two consecutive days. However, only 1183 (76%) persons completed the total dose. Three months later stool examination of about 20% of those who completed the total dose showed a cure rate of 68% and a significant reduction in the geometric mean egg counts. In those still positive redistribution of grades of infection took place; heavy infection, > 800 egg count per gram (epg), was reduced from 22.7% to 7.9% (p < .001) and light infection increased from 27.7% to 57.3% (p < .001) and light infection increased from 27.7% to 57.3% (p < .0001). The implications of this experience in the control of schistosomiasis in Ethiopia is discussed.

Transmission of schistosoma mansoni in three ecological settings in Ethiopia : epidemiological aspects

The epidemiological indices of Schistosoma mansoni for three communities in Ethiopia; Jigga (Northwest); Metahara sugar estate (Southeast) and Lake Zway (Central); each representing the three major transmission ecologies in the country; the stream; irrigation scheme and lake; respectively were studied and compared. A total of 2897 people (913; 1614 and 370 from the stream; irrigation scheme and lake; respectively) was examined for S. mansoni ova by the Kato's smear method. The highest human prevalence (58 per cent) and intensity of infection (geometric mean of 450 EPG) were recorded for the lake ecology; whereas the irrigation scheme and stream showed moderate (218 EPG) and light (172 EPG) intensities of infection; despite fairly high disease prevalences of 20 per cent and 41 per cent respectively. Age-specific analysis of prevalence; intensity of infection and relative index of potential contamination (RIPC) indicated that children in their second decade of life to be most responsible. Nevertheless; the decline of all indices with increasing age was less obvious in the lake area than others. The disparity between prevalence and intensity of infection and their implication in disease control tactics are discussed

Social and Ecological Aspects of Resettlement and Villagization among the Konso of Southwestern Ethiopia.

TEKLEMARIAM AYELE(2) This is a study of the changing settlement and land use patterns of the Konso in three peasant associations in southwestern Ethiopia and an evaluation of their attitudes toward government-sponsored villagization in the lowlands. Over the years, the Konso have moved spontaneously from the overpopulated highlands toward lower elevations and have recently begun to cultivate on the Yanda plain, but without settling there. Fear of tropical diseases, armed conflict with pastoralists and the Konso perception of lowland living continue to be powerful deterrents to settlement in the lowlands. Major objectives of the government villagization programme are unlikely to be achieved in the Konso area and may instead lead to disaster unless this programme is drastically revised to provide suitable conditions for resettlement and to meet the specific needs of the population.

A multidisciplinary study of onchocerciasis in Bure area, Ethiopia.

A clinicoepidemiological and entomological study of onchocerciasis was conducted in Bure area, Illubabor Administrative Region, in October 1987. All 1063 houses in four villages were numbered and census taken. The total population was 4119. Of the total 1063 houses, 107 (10.07%) were selected by systematic random sampling and all members of these households were examined. History, physical examination, and skin biopsy were taken. Of 4119 people in the area, 3555 (86.3%) were indigenous and 564 (13.7%) settlers. Four hundred and three of the former and 68 of the latter were studied. Clinical manifestations were mild and ocular onchocerciasis was not encountered. One hundred and sixteen (24.6%) had O. volvulus in the skin; with a mean of 11.7 microfilariae per milligram of skin. Positivity in males was 1 1/2 times that in females. None of the settlers had positive skin snips. We concluded that onchocerciasis is hypoendemic in Bure area with mild clinical manifestations. Adult and aquatic stages of Simulium were collected for later identification, and a preliminary report indicates that S. damnosum s.l. is the most likely vector.

Schistosomiasis in the Gumara and Ribb irrigation project area, Ethiopia.

A survey of intestinal schistosomiasis and vector snails was conducted in the Gumara and Ribb Irrigation project located on the eastern side of Lake Tana, northwest Ethiopia. Within the project area, stool specimens from 1273 people were examined by the thick smear method. The average infection rate for Schistosoma mansoni was 1.6%. Two localities, Addis Zemen and Yifag, located just outside the project area, were also examined, the former showing an S. mansoni prevalence of 34% (75/223) and the latter 18% (18/101) among school children. In Debre Tabor, the provincial capital 50 km away from the project site at an altitude of 2800 m., five S. mansoni cases were found among 111 school children, but they were considered to be imported cases. The possible establishment of intestinal schistosomiasis in the project area is discussed.

Helminth and snail survey in Harerge region of Ethiopia with special reference to schistosomiasis.

2300 persons from 25 communities in Harerge Administrative Region were examined for intestinal helminths. The overall prevalence rates were: Schistosoma mansoni 19.4%, Ascaris lumbricoides 13.4%, Trichuris trichiura 7.9%, and Taenia species 5.8%. Other parasites found in less than 3% included: Hymenolepis nana, Hymenolepis diminuta, Enterobius vermicularis, Strongyloides stercoralis and hookworms. Three age groups, 5-9, 10-14, and 15-19 years, had approximately similar prevalence (34.9-38.8%), but younger children had heavier egg loads (geometric mean egg output per gram of feces (EPG) of 347, 340 and 248, respectively). Boys had a higher prevalence of egg load than girls (42.4%, 395 EPG vs 26.5%, 277 EPG). Infection rates among Moslems were higher than Christians (45.5 vs 23.7%), but they had smaller egg output (333 vs 412 EPG). The frequency of light, moderate and heavy infections showed a normal distribution at 27, 46 and 27%. Biomphalaria pfeifferi was found to be infected with S. mansoni in Hirna (42/250), Esakly (6/80) and Genda Adem (20/200), the latter two in the Erer valley. Urine samples from 8 localities were negative for S. haematobium infection. The need for further study in several river valleys with agricultural potential is suggested.

Schistosomiasis in Ethiopia.

The literature on schistosomiasis in Ethiopia is reviewed with the objective of bringing together in one paper diverse sources which may not be available to those interested in schistosomiasis. Particular attention is given to the influence of altitude and climate, snail ecology and government economic programs on the distribution of schistosomiasis. Out of 365 communities studied between 1961 and 1986 for Schistosomiasis mansoni, cases were reported from 225 (62%), and in 85 (23%) the prevalence ranged from 10 to 92%. Most transmission sites and S. mansoni infections are in agricultural communities along streams between 1300 and 2000 m altitude infested with Biomphalaria pfeifferi, the major snail intermediate host. S. mansoni transmission above 2200 m and below 800 m is precluded in many parts of Ethiopia by low and high water temperatures, respectively. Schistosomiasis haematobium cases have been reported from 30 of the 54 communities studied, 17 of them with infection rates between 14 and 75%. Endemic S. haematobium appears to be confined in its distribution to lowlands below 800 m altitude. The highly focal distribution of S. haematobium transmission is largely due to the nonsusceptibility of most bulinine snails to the Ethiopian strain of the parasite and low water temperatures in the highlands. Water resources development, resettlement programs, refugee migration and other population movements may result in the spread of endemic S. mansoni. Lack of information on snail host/parasite relationships and the ecology of proven and suspected snail hosts does not permit predictions on the spread of endemic S. haematobium. Past and present schistosomiasis control programs in Ethiopia are reviewed and recommendations made for the national control program.

The distribution of visceral leishmaniasis in Ethiopia.

A total of 50 cases of visceral leishmaniasis (VL) were diagnosed among 1,184 patients examined in different parts of Ethiopia. The overall male: female sex ratio was 4:1. About 56% of the cases occurred in the 15- to 29-year age group. The incidence of VL in Aba Roba Village was 5.2 per 1,000 population. New foci of transmission identified include lowlands of Algena, Nakfa, Afabet, Teseney, and Genale River Basin, and west of Moyale.