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R Yagil

Publications and source records attributed to R Yagil.

At least 19 recordsLinked to original sources
PubMed2003

Reactions of peripheral blood mononuclear cells (PBMC) of camels with monoclonal antibodies against ruminant leukocytes.

The particular immune system of the camel has been but little investigated. In this work circulating camel peripheral blood mononuclear cells (PBMC) were studied by flow cytometry. Monoclonal antibodies (mAbs) raised against ruminant leukocytes were used for the detection of cell surface antigens. Monoclonals to T-cell markers, CD4 (CACT138A) and CD8 (CACT80C), exhibited no reactivity towards camel PBMC in contrast to their reactivity to PBMC of other ruminant species and those of cattle in particular. A relatively high percentage (29.1+/-8.9%) of camel PBMC reacted with a non-immunoglobulin cell surface marker, B-B2, comparable to the reactivity of bovine PBMC. The B-B7 cell marker revealed 22.4+/-10.0% of reactive camel PBMC while the CD45 leukocyte common antigen was identified only on 19.4+/-3.1% of camel PBMC as compared to 74.7+/-4.9% for bovine PBMC. IgM (PIg45A) was detected on 9.1+/-1.4% of camel PBMC and on 46.6+/-19.5% of the bovine PBMC. Double fluorescent labeling with two B-cell markers and an anti-ruminant lambda light-chain mAb revealed 7-9% of cells bearing both B and lambda L-chain markers. Light chain reactivity was also assessed using an anti-goat F(ab')(2) antiserum. The values obtained, 14.3+/-5.8% for the camel and 47.8+/-2.7% for the cattle, are close to the values observed for surface IgM. These data suggest that camels, like other ruminants, possess L-chain bearing cells of the B-cell lineage. However, in the camel, Igs are different in that in addition to regular four chain Igs, about 65% of them possess two heavy chain Igs devoid of light chains. Because different sets of V(H) gene segments are used by four and two chain Igs, it is possible that there might be two lineages of B-cells each secreting a different form of antibodies.

Animals↗
PubMed2002

Detection of subclinical mastitis in dromedary camels (Camelus dromedarius) using somatic cell counts and the N-acetyl-beta-D-glucosaminidase test.

Somatic cell counts, N-acetyl-beta-D-glucosaminidase (NAGase) activity and the infection status of the udder were determined in quarter milk samples (n = 86) from 22 multiparous, clinically healthy camels, traditionally managed by Bedouin nomads in the Negev desert, Israel. Seventy (81.4%) of the 86 samples examined contained bacteria, of which 35 (40.7%) gave mixed isolations of two or more bacteria, suggesting the existence of subclinical mastitis in the camel herds studied. Sixteen samples (18.6%) yielded no growth of bacteria. Staphylococcus aureus, Micrococcus spp., Bacillus spp., Streptococcus dysgalactiae and Escherichia coli were the main organisms isolated. The somatic cell count (SCC) ranged from 1.01 x 105 to 11.78 x 106 cells/ml. NAGase values were between 41.4 and 372 NAGase units. Quarter milk samples that contained bacteria had significantly (p < 0.01) higher mean values for SCC but the mean NAGase levels were not significantly different for the bacteriologically negative and positive samples. There was a low correlation coefficient (r2 = 0.097) between the SCC and NAGase in the quarter milk samples from which bacteria were not isolated (n = 16) and a low negative correlation (r2 = -0.038) with the samples that contained bacteria (n = 70). The type of bacteria had a significant effect (p < 0.01) on the SCC but not on the NAGase activity. Quarter samples from which Staphylococcus aureus (coagulase positive) was isolated showed the highest mean SCC and this organism is therefore suspected to be the underlying cause of the subclinical mastitis. The SCC gave a better indication of the presence of pathogenic microorganisms in milk samples than did NAGase.

Acetylglucosaminidase↗
PubMed1996

The bioavailability of febantel in dehydrated camels.

In the present study the bioavailability of febantel paste and febantel suspension was investigated in the fully hydrated and the dehydrated camel. The serum concentrations of febantel and its metabolites, fenbendazole, oxfendazole and fenbendazole sulfone were determined by high performance liquid chromatography following extraction with ether. The exposure to febantel and its metabolites in fully hydrated camels was significantly higher in camels dosed with febantel paste compared to febantel suspension, as measured by AUC and Cmax. The AUC and Cmax of fenbendazole and oxfendazole were significantly lower in dehydrated camels as compared to control camels dosed with febantel paste. The systemic availability of febantel suspension in control and dehydrated camels was very low and differences between dehydration and control phases were insignificant. The low systemic availability of febantel in camels dosed with febantel suspension may cause nematodes to become resistant to this anthelmintic. It is, thus, suggested to increase the dose of febantel paste in dehydrated camels in order to increase the exposure to febantel and its metabolites. The binding of febantel, fenbendazole, oxfendazole and fenbendazole sulfone to camels' serum proteins was over 85%. Oxfendazole was only about 70% bound. Dehydration of 10 days did not affect the binding of these benzimidazole derivatives to serum proteins.

Administration, Oral↗
PubMed1995

Antipyrine disposition in the dehydrated camel.

In the present study the effects of water deprivation in the camel (Camelus dromedarius) on the pharmacokinetic profile of antipyrine were assessed. A cross-over design was used. The pharmacokinetics of antipyrine in adult and young camels were compared. Antipyrine was administered intravenously to young and adult female camels when water was available ad libitum and to the adult camels after 14 days of dehydration. The elimination half-life of antipyrine in watered adult camels was 136.5 +/- 16.7 min. The half-life of elimination and the mean residence time of antipyrine were significantly prolonged following dehydration. The observed effects of water deprivation were not a function of age, as the pharmacokinetic profile of antipyrine in young camels was similar to that of the adults, but more likely due to the changes in oxidative metabolic capacity of the liver as a result of a reduced general metabolism. The results of the present study also show that the intrinsic clearance of antipyrine is proportional to the camel's body weight, as previously shown for other mammalian species.

Aging↗
PubMed1995

Disposition kinetics of tylosin tartrate administered intravenously and intramuscularly to normal and water-deprived camels.

The disposition kinetics of tylosin tartrate administered intravenously (i.v.) at 10 mg/kg and intramuscularly (i.m.) at 20 mg/kg were studied in normal camels and in the same camels at the end of a 14 day water-deprivation period. After i.v. treatment, serum tylosin concentrations in the water-deprived camels were significantly higher, rate of drug elimination was slower, the volume of distribution was significantly smaller, and total body clearance was significantly slower than in the normal camels. On the other hand, serum drug concentrations were lower in the water deprived camels after i.m. dosing, the mean absorption time was significantly shorter and the i.m. availability was significantly smaller than in the normal camels. Water-deprivation was thought to cause reduced rate of tylosin elimination by the liver, as was shown for antipyrine--a drug which is eliminated from the body exclusively by the liver. Redistribution of tylosin in tissues concomitant with a greater proportion of drug in blood and extracellular fluid of water-deprived camels was suggested as a partial explanation for the higher serum drug levels seen after i.v. dosing. The low i.m. availability observed in the water-deprived camels implies that i.v. is the route of choice for tylosin administration to ill, dehydrated camels.

Animals↗
PubMed1995

Effect of water deprivation on the disposition kinetics of enrofloxacin in camels.

Concentrations of enrofloxacin equivalent activity were determined (by microbiological assay) in the serum of normal camels and camels at the end of a 14-day water-deprivation period following single intravenous (i.v.), intramuscular (i.m.) and subcutaneous (s.c.) administrations at 2.5 mg/kg. Also, normal camels were given an oral drench of the drug at 5 mg/kg. Pharmacokinetic variables were determined using compartmental and non-compartmental analytical methods. Camels lost on average 12.5% of body weight at the end of the water-deprivation period. The disposition kinetics of i.v. administered drug in normal and water-deprived camels were very similar. The t1/2 beta was 3.0-3.5 h; MRT was 4.0-4.5 h; Vc was 0.3 L/kg; Vss was 1.0 L/kg and ClB was 4.0-4.6 mL/min/kg. The effect of water deprivation on the rate of drug absorption and elimination after i.m. administration was inconsistent, and there was also a large degree of variability in the normal animals that precluded statistical significance. After s.c. administration, the mean absorption half-life (t1/2abs) in the water-deprived camels was significantly longer than in the normal camels. Systemic availability (F) was similar in both normal and water-deprived camels after i.m. dosing but was significantly greater (P < 0.05) in normal camels (0.92 compared with 0.65 in water-deprived camels) after s.c. treatment. In normal camels, urinary recovery at 12 h after i.v. and s.c. dosing was 25% and 15%, respectively, and the extent of serum protein binding ranged between 1.7% at 1.8 micrograms/mL and 24% at 0.33 microgram/mL. The drug was not detected in serum after oral administration. Serum and milk enrofloxacin equivalent activities were determined after i.v. (one camel) and i.m. (one camel) drug administration. Serum drug concentrations were consistently higher than in the milk. The AUCmilk/AUCserum ratios were 0.27 and 0.39 after i.v. and i.m. drug administration, respectively. An i.m. or s.c. treatment regimen of 2.5 mg/kg q.12 h is suggested for clinical and bacteriological efficacy trials with enrofloxacin in normally hydrated and dehydrated camels.

Absorption↗
PubMed1995

Lidocaine elimination and monoethylglycinexylidide formation in the dehydrated camel.

The elimination kinetics and the formation of the monoethylglycinexylidide (MEGX), a major metabolite of lidocaine, were studied in camels deprived of water for 14 days. The study was conducted on four camels in a crossover design. Lidocaine was administered intravenously at a dose of 1 mg/kg to adult female camels when water was given ad libitum (stage 1) and to the same camels after 14 days of dehydration. Blood samples were taken up to 6 h after dosing. Serum lidocaine and MEGX levels were analysed by polarization fluorescence immunoassay. The elimination profiles of lidocaine and the formation of the metabolite MEGX in the two phases of the study were essentially identical. No difference in any pharmacokinetic parameter was noticed between normally hydrated and water-deprived camels. It is thus concluded that dehydration does not affect the cytochrome P450 isozymes involved in degradation of lidocaine to MEGX nor does it affect the hepatic blood flow, which is a major determinant in the clearance of lidocaine. The very low clearance of lidocaine in the camel in comparison with other ruminant or monogastric mammals may be associated with the camel's ability to survive drought in the desert.

Anesthetics, Local↗
PubMed1989

Liver function and protein binding in camels.

1. Dehydration of camels for 10 days resulted in reduction of liver functions, expressed in longer half life and reduced clearance of bromosulfophthalein (BSP), elevated AST (ALT levels were below the limit of detection of the method) and reduced serum albumin concentrations. 2. Binding of BSP to camel serum proteins by gel permeation chromatography and by equilibrium dialysis showed very strong binding. 3. Binding parameters of various drugs to camels serum by equilibrium dialysis showed close similarities both qualitatively and quantitatively to those of humans. 4. Albumin seems to be the major serum binding protein of BSP.

Alanine Transaminase↗
PubMed1989

Reference blood chemical values in ostriches (Struthio camelus).

Reference blood chemical values were determined for 65 male and 61 female ostriches (Struthio camelus) 1 month to 72 months of age. Plasma values of glucose, total protein, triglycerides, cholesterol, uric acid, urea, bilirubin, creatinine, osmolality, electrolytes, and enzyme activity were determined. In general, differences in various values appeared mainly among age groups and less so between sexes. Older ostriches had lower plasma glucose values and enzyme activity than did younger ostriches. High plasma sodium and chloride concentrations in young ostriches correlated with high plasma osmolalities. Plasma calcium values were lower in laying ostriches. Uric acid concentrations were markedly higher than were urea concentrations in all ostriches.

Age Factors↗
PubMed1987

Metabolic effects in rats drinking increasing concentrations of sea-water.

Research on laboratory rats confirmed that drinking sea-water when dehydrated, was not beneficial and caused impaired renal function. When the concentration of sea-water in the drinking water is gradually increased there is a gradual increase in water uptake and corresponding urine excretion. At 50% sea-water the maximum uptake and excretion is reached. Following this there is a decline in appetite, water uptake and urine secretion. When on 100% sea-water, the creatinine clearances were greater than on tap water, while urine/plasma osmolalities (U/P) averaged 7. The only higher U/P was found in animals drinking sea-water when dehydrated, i.e. a U/P of 11. The urea metabolism appears to be suited to either the need to conserve body water, up to 50% sea-water, or to guarantee an adequate urine production, from 50% sea-water to pure sea-water. It is suggested that when a man is stranded at sea it is not advisable to drink all the fresh water and then be compelled to drink sea-water when dehydrated. It is better to slowly increase the sea-water uptake. This will prolong the time before sea-water needs to be drunk and result in only minor metabolic changes. Return to fresh water will be followed by an immediate return to normal homeostasis.

Animals↗
PubMed1984

Estradiol concentration in the serum of the one-humped camel (Camelus dromedarius) during the various reproductive stages.

During the estrous cycle of the camel the concentration of estradiol (E2) varies between 9 and 110 pg/ml. In early estrus, the peak level of E2 (74.7 +/- 6.61 pg/ml, n = 11) is maintained for 2.9 +/- 1.83 days. The length of an estrous cycle is 17.2 days. In the 10th month of pregnancy the level of E2 rises abruptly to 338.3 +/- 162.42 pg/ml and continues to rise until the 12th month, peaking at 606 +/- 120.27 pg/ml. The hormone concentration then drops until the day of parturition (mean 113.4 +/- 26.51 pg/ml). The level of E2 during the nonbreeding season (May-November) is low (6-48 pg/ml).

Animals↗
PubMed1984

Peripheral blood levels of progesterone in female camels during various reproductive stages.

Determination of serum progesterone concentrations over a period of 2 years in female camels during various reproductive stages (estrus, pregnant, nonpregnant, and lactating) suggests that the progesterone levels exceeding 1 ng/ml are reached only if mating is fertile. A cycling camel does not have a luteal phase and mating is probably indispensable for ovulation to occur.

Animals↗
PubMed1984

Camels' milk: for drinking only?

Camels' milk, women's milk and cows' milk were kept at 30 degrees C and refrigerated at 4 degrees C. This explains the necessity to immediately freeze milk if it needs to be kept even for a few days. Cows' milk remained good for days if stirred and then turned sour, enabling the making of cheeses and butter. Camels' milk did not sour at 4 degrees C for up to 3 months. This means that camels' milk is mainly good only for drinking, as was promised to this animal by the Prophet.

Animals↗
PubMed1984

Tritiated water metabolism during dehydration and rehydration in the camel.

The metabolism of tritiated water in the camel was compared in two 10-day periods, one when water was readily available and the second during dehydration. There was a radically depressed metabolism after 2 days of dehydration. Two other experiments examined the absorption rate of drinking water. In one experiment drinking water was labeled with tritium, and in the second experiment dilution of tritium-labeled blood was examined. In both experiments there was a rapid uptake and dilution of the blood, which continued for 4 h. Following this only slight changes were observed up to 24 h after drinking. The results are in accord with other data showing changes in erythrocyte shape 4 h after rapid rehydration. It is concluded that there is a rapid absorption of water in the rehydrating camel.

Absorption↗
PubMed1984

Hormonal control of fracture healing in a dog with chorea.

An experimental fracture in a dog with chorea was found to heal faster, and with a larger callus, than normal. Serum levels of parathormone (PTH), calcitonin (CT) and vitamin D metabolities were determined during callus formation. Serum concentrations of vitamin D metabolites were lower from the beginning while serum CT levels were higher compared to normal dogs. A massive increase in serum levels of 24,25-dihydroxyvitamin D was noted during the healing period. These results and observations suggest the existence of some disturbances in the secretion of hormones regulating calcium metabolism during bone repair where a nervous system lesion exists.

Animals↗
PubMed1982

Growth and bone mineralisation as affected by dietary calcium, phytic acid and vitamin D.

1. Rats were fed various diets ranging from the normal chow, pure flour containing large amounts of phytic acid, Ca-enriched flour and mixtures of flour and normal food with various levels of calcium. 2. It was found that the animals eating the pure flour grew less and were smaller. 3. They suffered from hypocalcemia and had low plasma alkaline phosphatase and 25-HCC-vitamin D3 levels. 4. These animals had rib-cage deformities. 5. Additional calcium in the flour improved the animals' growth and calcification. 6. The mixed food did not greatly affect the animals and additional calcium did not improve growth or bone mineralisation. 7. The Bedouin eat large amounts of unleavened bread containing large amounts of phytates. 8. It is concluded that uptake of large amounts of phytates by the Bedouin eating unleavened bread is due to the flour and that the clinical manifestations are a direct result of the flour and not the lack of vitamin D due to covering the skin from sunlight.

Animals↗