PubMed Health⌕ Search

Biomedical subjects

A Dakkak

Publications and source records attributed to A Dakkak.

At least 19 recordsLinked to original sources
PubMed2005

Identification of two highly performing Leishmania infantum antigens for serodiagnosis of canine leishmaniosis.

In the aim of improving serodiagnosis of canine leishmaniosis, we analysed the humoral immune response of dog against Leishmania infantum parasite. The antigenic reaction of L. infantum polypeptides with sera from 31 dogs with parasitologically confirmed leishmaniosis was studied by using the immunoblot technique. Electrophoretic profile of the parasite extract showed more than 50 polypeptides, with molecular weights ranging from 12 to 170 kDa. Among these polypeptides, 37 antigen components, ranging from 14 to 91 kDa, were recognised by antibodies of L. infantum infected dogs. Three polypeptides (14, 16 and 76 kDa) reacted with all of the 31 serum samples. The other most frequently recognised antigens were those of 29.5, 32, 46, 59 and 66 kDa with a sensitivity of 87.1%, 93.6%, 96.8%, 87.1% and 80.6%, respectively. The 14 and 16 kDa bands were the most intense and remained detectable until a serum dilution of 1:6400. No reaction of these two major antigens was observed with sera collected from 50 Leishmania-free dogs, living in the leishmaniosis-free region of Rabat in Morocco, whereas the crude antigen used in IFAT or ELISA lead to three false positive results. Four antigen components of 29, 41, 55, and 70 kDa were recognised by some sera samples from negative controls. These results demonstrated the potential interest of the fractions of 14 and 16 kDa in immunodiagnosis of canine leishmaniosis.

Animals↗
PubMed2003

Camel trypanosomosis in Morocco. 2. A pilot disease control trial.

A first epidemiological study on camel trypanosomosis was conducted in 1997 and 1998 in five Moroccan Saharan provinces. It revealed two major foci at Merzouga (Tafilalet province) and Zagora (Ouarzazate province) where tour camel seroprevalences were 35.4 and 43.3%, respectively, for each region. The first area was chosen in the present study as a pilot region for a control program based on epidemiological data with the aim of evaluating the efficiency of the trial in terms of seroconversion, incidence and health condition. After finding the endemic focus at Merzouga, four other field studies were organised in this area, at 4-month intervals, in order, firstly, to control the camel reservoir by treating all the camels found in the region during the visit using melarsomine (Cymelarsan, Rhône-Mérieux, the only trypanocide registered in Morocco), and, secondly, to collect blood samples for studying temporal changes in seroprevalence as well as in anaemia rate. All the 291 tour camels of the area, that were present in at least one of the field visits were examined and included in the trial. Among them, 162 were treated once, 84 twice and 41 three times. A total of 676 serum samples were collected from these camels. At the end of the trial--1 year later--seroprevalence had dropped from 58% (May 1998) to 19% and the mean Ab-ELISA value had decreased from 0.52 (before treatment) to 0.12 (which is below the threshold level), after the third campaign. The haematocrit of the animals was also slightly improved, indicating that trypanosomosis was a major cause, but it was not the only incriminated factor. A seasonal effect was observed. The overall seroprevalence was reduced between spring 1999 and summer 1999, without treatment, whereas a negative effect was recorded on packed cell volume, more camels being found anaemic in summer than in spring. The application of these strategic treatments was associated with a large reduction in the seroprevalence of trypanosomosis, but there was no complete eradication because of the continual exchange of animals from other foci such that of Zagora. The overall seroconversion after 1 year reached 55% and no post-treatment complication was recorded, whereas the incidence due to new infections approached 4.3%. Moreover, several factors like the unusual way of life of the dromedaries, including stress, excessive work, overcrowding and continual contact with other animals coming from other infected regions contribute to the persistence of the disease.

Animals↗
PubMed2003

Camel trypanosomosis in Morocco 1: results of a first epidemiological survey.

An epidemiological survey of camel trypanosomosis was conducted for the first time in Morocco in 1997 and 1998. Five provinces located in the south and southeast of the High Atlas mountain chain were included in this study. A total number of 1460 serum samples were collected and tested by a card agglutination test for trypanosomosis (CATT) and enzyme-linked immunosorbant assay (Ab-ELISA) to detect anti-Trypanosoma evansi antibodies. The overall seroprevalence was 14.1% by CATT and 18.2% by Ab-ELISA. Two very active foci were identified in Zagora and Merzouga with high Ab-ELISA prevalences of 43.3 and 35.4%, respectively, for each area. The concordance between the CATT and Ab-ELISA was 94.1%. The age-related distribution of seroprevalence showed a tendency for the infection rate to increase with age up to a maximum in the 7-10 year-old group. Clinical examination revealed that enlargement of lymph nodes was the most frequent sign in seropositive animals (79.7%). The comparison of haematocrit values of seropositive and seronegative animals showed a significant difference that indicated severe anaemia in infected animals. Isolation of the parasite by inoculation of mice allowed us to collect 15 T. evansi isolates from Zagora and three from Merzouga. The study showed that the Saharan provinces of Morocco were slightly affected by camel trypanosomosis but two hyperendemic foci, Zagora and Merzouga, were found to be sources of contamination for the surrounding regions.

Aging↗
PubMed2003

[Canine leishmaniasis in the Rif mountains (Moroccan Mediterranean coast): a seroepidemiological survey].

A sero-epidemiological survey has been conducted in several localities of the province of Nador to investigate canine leishmaniasis in the North-Eastern slope of the Rif mountains (Mediterranean coast of Morocco). Serum samples collected from 257 dogs were analysed using indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) to detect anti-Leishmania infantum antibodies. Forty eight (18.7%) of the screened dogs were IFAT positive and 54 (21.0%) were ELISA positive; the concordance of the two methods was 96.1%. The prevalence of infection is significantly higher in dogs more than four years of age whereas no significant difference in prevalence of infection was seen between males and females. The frequent symptoms observed in seropositive dogs were the enlargement of lymph nodes (57.4%), emaciation (51.9%) and skin involvement (25.9%). However, 38.9% of those dogs showed no one of the major symptoms of visceral leishmaniasis. Leishmania isolated from three of the examined dogs was identified as L. infantum MON-1. These results show that the North-Eastern slope of the Rif mountains is one of the most active Mediterranean areas of visceral leishmaniasis and confirm that the dog is the main reservoir of L. infantum.

Age Distribution↗
PubMed2003

A prospective, randomized, controlled trial comparing highly purified hMG with recombinant FSH in women undergoing ICSI: ovarian response and clinical outcomes.

BACKGROUND: To assess the clinical profile and efficacy in assisted reproductive treatment of a new human-derived highly purified (HP) menotropin, we compared HP hMG and recombinant (r) FSHalpha use in ICSI within a prospective, randomized, controlled study. METHODS: 100 infertile women were treated with HP hMG (50 patients) or rFSHalpha (50 patients). All patients received the same daily gonadotrophin dose (150 IU) following GnRH agonist suppression (long regimen) until more than three follicles >17 mm and estradiol (E(2)) levels >600 pg/ml were reached. Patients were monitored with daily LH, FSH, hCG, estradiol (E(2)), progesterone, and testosterone measurements; and alternate day pelvic ultrasound. RESULTS: Treatment duration (11.1 +/- 0.4 versus 12.9 +/- 0.5 days, P < 0.05) and gonadotrophin dose (22.4 +/- 1.0 versus 27.0 +/- 1.5 ampoules, P < 0.05) were lower in the HP hMG group. Conversely, peak pre-ovulatory E(2) (1342 +/- 127 versus 933 +/- 109 pg/ml, P < 0.005); and area under the curve of E(2) (3491 +/- 350 versus 2602 +/- 349 pg/ml.day, P < 0.05), immunoreactive serum FSH (65.9 +/- 2.1 versus 48.8 +/- 1.8 IU/l.day, P < 0.001). and hCG (1.7 +/- 0.3 versus 0.0 +/- 0.0 IU/l/day, P < 0.001) during treatment were higher in the HP hMG group. Cycle cancellation rates, transferred embryo number, pregnancy rates per started cycle (30 versus 28%) and per embryo transfer (35 versus 35%) and miscarriage rates (6 versus 6%) were not significantly different. CONCLUSIONS: HP hMG treatment was associated with: (i) a more efficient patient response, as reflected by reduced treatment duration and gonadotrophin requirements; (ii) increased serum levels of hCG, E(2), and immunoreactive FSH during treatment; (iii) an ICSI outcome indistinguishable from rFSHalpha.

Abortion, Spontaneous↗
PubMed1993

Protective oral immunization of chickens against Eimeria tenella with sporozoite surface antigens.

Antigens were extracted from the surface of Eimeria tenella sporozoites with a solution containing Triton X 100 (1%), sodium dodecyl sulphate (0.5%) Na deoxycholate (1%) and EDTA (1 mM). After removal of the detergents, these surface antigen preparations conferred an immunity that protected chickens against a subsequent infection (10(4) sporulated oocysts). The best results were obtained after two 250 micrograms injections of Al(OH)3 adsorbed antigens (oocyst output per g caecal material on Day 7 post infection: 2.39 x 10(7) +/- 0.32 x 10(7) oocysts for controls and 7.37 +/- 10(6) +/- 3.19 x 10(6) oocysts for vaccinated birds) and after four gastric intubations of liposome entrapped antigens (oocysts output on Day 7 postinfection: 2.75 x 10(6) +/- 2.02 x 10(6) g-1 caecal material). These results represented respectively 70 and 88% protection indexes. Studies on the systemic and local antibody response after one or several infections of chickens with the parasite indicated at least 20 different molecules in the detergent antigens which are classified after immunoblotting according to their properties.

Administration, Oral↗
PubMed1993

Effect of temperature and relative humidity on survival of eggs and infective larvae of Ostertagia circumcincta.

Survival of Ostertagia circumcincta eggs in faeces kept at 4 degrees C and of third stage larvae (L3) kept in distilled water at -50, -25, -10, 4, 16, 25 and 35 degrees C was studied. The effect of relative humidity (RH) of 95, 75, 50 and 30% at 16, 25 and 35 degrees C on the survival of L3 was also studied. The survival of eggs at 4 degrees C was high during the first week, followed by a gradual decline to 10% by Day 22 of storage. The L3 survived for 7 weeks at -50 degrees C, 9 weeks at -25 degrees C, 13 weeks at -10 degrees C, and 7 weeks at 35 degrees C. By 16 weeks, at the termination of the experiments, 74%, 76% and 23% of L3 were still alive at 4 degrees C, 16 degrees C and 25 degrees C, respectively. At all temperatures tested, the L3 survived longer at RH of 30 and 50% than at 75 and 95%. At 35 degrees C, L3 survived up to 6 weeks at 30%, 5 weeks at 50% and 1 week at 75 and 95% RH. At 16 and 25 degrees C and RH of 30 and 50%, over 70% of L3 were still alive at the end of experiments at the seventh week. At 25 degrees C, 40% of L3 survived for up to 5 weeks at 75% RH and 5% survived for 6 weeks at 95% RH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Seasonal dynamics of Fasciola hepatica burdens in grazing Timahdit sheep in Morocco.

Seasonal transmission of Fasciola hepatica was observed in sentinel sheep and the dynamics of the snail intermediate host, Lymnaea truncatula, was followed over a 3-year study period in the Middle-Atlas mountains in Morocco. High fluke burdens were recorded in both lambs and ewes in the fall and winter, suggesting that transmission occurred in late spring. Fluke burdens ranged from one to 302 in ewes and from one to 345 in lambs. Infections with 200 or more flukes were always fatal. A unique feature of this study was the annual cyclical fluctuation of the fluke burdens. Burdens reached maximum levels during the winter and then declined to low numbers by late spring and summer. This suggested self-regulation which may be dependent on breed resistance or may be related to forage factors, including lack of forage (nutritional stress). Snail populations were cyclical and correlated with fluke transmission as observed in the sentinel sheep. The weather was observed to affect the snail populations which in turn limited fluke transmission.

Animals↗
PubMed1990

[Gastrointestinal strongylosis and malabsorption of nutrients].

The role of malabsorption of nutrients in the mechanism of reduction in productions of the ruminants infested with gastrointestinal nematodes has been a controversial question because of the compensatory absorption and reabsorption in distal part of the small intestine. However, during the last decade, leading research showed that malabsorption has a major role in this mechanism because of 1) compensatory absorption and reabsorption remain limited to some nutrients, 2) large quantities of incompletely digested nutrients exceeding the intestine capacity, and 3) poor reutilization of reabsorbed nutrients.

Animals↗
PubMed1989

Effect of temperature on development of the free-living stages of Ostertagia circumcincta.

Hatching of the eggs of Ostertagia circumcincta was studied by recovering them from faeces and incubating them in distilled water at temperatures of 4, 16, 25 and 35 degrees C. Hatching occurred at all the temperatures. The rate of hatching increased with the rise in temperature. Development of larvae to the infective third stage (L3) was studied in faecal cultures incubated at 4, 16, 25, 30, 35, 40 and 45 degrees C. Except at 4 degrees C, L3 developed at all temperatures, the optimum temperature being 16 degrees C. The rate of development of L3 increased with the rise in temperature. This resulted in a corresponding decrease in the percentage recovery of larvae.

Animals↗
PubMed1987

Parasites of stray dogs in the Rabat region, Morocco.

Eighteen parasites were identified from 57 stray dogs from the urban and rural areas of Rabat. The prevalence of the species of parasites was: Ctenocephalides (C. canis, C. felis) 94.7%, Rhipicephalus sanguineus 68.5%, Linguatula serrata, Babesia canis, Isospora canis each 3.5%, Toxocara canis 7%, Dirofilaria immitis, Taenia hydatigena, T. pisiformis each 12.3%, Dipetalonema dracunculoides 10.5%, Ancylostoma caninum 17.5% Echinococcus granulosus 22.8%, Toxascaris leonina 33.3%, Dipylidium caninum 40.4%, Spirocerca lupi 54.5%, Unicinaria stenocephala 79%. Multiple infections (two to nine parasites) were seen in 56 dogs. T. canis was present only in dogs younger than one year of age. D. immitis, D. dracunculoides, T. hydatigena and T. pisiformis occurred only in animals older than one year. A. caninum, U. stenocephala, S. lupi, D. immitis were more common in males than females. E. granulosus was never detected in urban dogs.

Age Factors↗
PubMed1985

Haemonchus contortus and Ostertagia circumcincta: fenbendazole treatment and abomasal permeability changes in sheep.

Effects of fenbendazole (7.5 mg/kg of body weight infused during 90 minutes) on abomasal transmural potential difference (PD), pH, and ionic concentrations were determined in 8 lambs fitted with permanent abomasal cannulae. Four sheep were treated before inoculation and on day 28 after inoculation, with 200,000 3rd-stage Ostertagia circumcincta larvae and 4 others were similarly inoculated with 15,000 3rd-stage Haemonchus contortus larvae. In worm-free lambs, the unique effect was an increase in Na+ concentration of the abomasal contents. The O circumcincta or H contortus-inoculated lambs had an increase in PD, pH, and Na+ concentrations. Treatment further increased these concentrations, but the effects on PD occurred and ceased earlier in sheep inoculated with O circumcincta than in those inoculated with H contortus. The results indicated that part of the changes were linked to substances produced by the parasites or by the host. The increase in PD and pH was associated with a decrease in K+ concentration and indicated that these substances stimulated HCO3- transfer.

Abomasum↗
PubMed1984

[Physiopathology of ovine ostertagiasis. Effects of experimental infection by Ostertagia circumscripta on various parameters as indicators of abomasum function].

The measurement of the pH and Na+, K+, Ca++ and Cl- concentrations of the stomach or the abomasal contents allow the functioning statement of these organs to be determined. In the present work, these parameters were measured, at 2 day intervals, in six lambs fitted with permanent abomasal cannulae and experimentally infected with 150 000 O. circumcincta infective larvae. Infection was followed by a significant (P less than 0.01) increase in pH and Na+ and Ca++ concentrations, and a significant (P less than 0.01) decrease in K+ and Cl- concentrations of the abomasal contents. The disorders start when the 4th stage larvae begin to emerge from the mucosae (from the 4th to the 12th day infection) and become more marked between the 16th and the 32nd day; this means when the egg output starts and becomes marked. The disturbances noted in the present work suggest: 1) a defective working of HCl production mechanism; 2) an intraluminal diffusion of the interstitial liquid; 3) a stimulation of pepsin production. These disorders would have consequences on the functioning of the other parts of the digestive tract.

Abomasum↗
PubMed1984

[Kinetics of the population of worms in various developmental stages, Haemonchus contortus in sheep after a single experimental infection] experimental infection].

This work was performed to study, in 147 month-old male lambs experimentally infected with 14000 Haemonchus contortus infective larvae and slaughtered at 6, 12, 18 and 24h and at 2, 6, 8, 11, 15 and 39 days post-infection (pi): 1, the importance, localisation and nature (with or without sheath) of the worms during the first 24 h pi; 2, the kinetics of the total worm population and of each evolutionary stages from the first to the 39th day pi: 3, the period of emergence of the fourth-stage larvae from the mucosae; 4, the topographic distribution of the different evolutionary stages of the parasite in the abomasum. During the first 24 h pi, the total worm population and that of the intramucosal larvae increase in lineary function to time (r = 0.98). After a maximum value, reached between 24 and 48 h pi, the total worm population decreases in lineary function to time (r = -0.94). Only 52% approximately of the larvae administered develop. One of the reasons is the fact that a proportion of 3rd stage larvae cannot leave their sheath during the rumino-omasal transit. Other limiting factors are discussed. The fourth-stage larvae appear in the mucosae 24 h pi. Their emergence from the mucosae starts between day 1 and 2 pi and increases in intensity from days 2 to 6 pi. The immature adults and the adults are encountered from days 6 and 14 pi respectively, and the prepatent period is on average 16 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Abomasum↗