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H Khatib

Publications and source records attributed to H Khatib.

At least 19 recordsLinked to original sources
PubMed2006

Association of the OLR1 gene with milk composition in Holstein dairy cattle.

Oxidized low-density lipoprotein receptor (OLR1) is the major protein that binds, internalizes, and degrades oxidized low-density lipoprotein. The role of OLR1 in lipid metabolism and the results of previous whole-genome scan studies prompted the investigation of OLR1 as a candidate gene affecting milk composition traits. Direct cDNA and genomic sequencing of OLR1 revealed 2 single nucleotide polymorphisms (SNP) in exon 4, 5 SNP in intron 4, and 1 in the 3' untranslated region (UTR). Four intragenic haplotypes comprising SNP positions 7,160, 7,161, 7,278, 7,381, 7,409, 7,438, 7,512, and 8,232 were inferred. Haplotype analysis showed that one of the haplotypes was associated with a significant increase in fat yield and fat percentage. Single SNP analysis showed that allele C of SNP 8,232 (in the 3'-UTR) had significant effects on fat yield and fat percentage, whereas SNP 7,160 and 7,161 (in exon 4) had no significant effects. Both single SNP and haplotype analyses indicate that SNP 8,232 in the 3'-UTR is associated with milk fat yield and percentage and it may be in linkage disequilibrium with the functional polymorphism. To provide support for the hypothesis that SNP 8,232 is responsible for OLR1 expression, OLR1 expression levels in individuals bearing different genotypes were assessed. It was found that OLR1 expression was reduced in genotype AA individuals compared with CC and AC individuals, suggesting that A at position 8,232 may be the nucleotide causing decreased OLR1 expression. The 3'-UTR polymorphism found in this study might control translation or stability of OLR1 mRNA.

3' Untranslated Regions↗
PubMed2006

Changes in conception rate, calving performance, and calf health and survival from the use of crossbred Jersey x Holstein sires as mates for Holstein dams.

Differences in conception rates in matings of Holstein sires or F1 Jersey x Holstein sires to Holstein dams in the University of Wisconsin-Madison experimental herd were evaluated, as were differences in birth weight, dystocia, serum protein, serum IgG, fecal consistency, respiratory disease, and perinatal and pre-weaning mortality among the resulting calves. When mated to randomly chosen, lactating Holstein cows, Holstein sires (n = 74) and crossbred sires (n = 7) did not differ in male fertility. Calves from Holstein sires and multiparous Holstein dams (n = 99) were 1.9 kg heavier than calves from crossbred sires and multiparous Holstein dams (n = 211), leading to greater likelihood (odds ratio of 1.24) of dystocia. Furthermore, calves from crossbred sires and multiparous Holstein dams had higher serum protein and serum IgG levels between 24 and 72 h of age, as well as lower rates of perinatal and preweaning morality than calves from Holstein sires and multiparous or primiparous Holstein dams. Mean fecal consistency scores from birth to 7 d of age and number of days with scours also tended to be lower among calves from crossbred sires, compared with calves from Holstein sires. No differences were observed in the incidence or severity of respiratory disease. Results of this study suggest that introduction of Jersey genes via crossbreeding may lead to a reduction in dystocia and improvements in calf health and survival in Holstein herds. Future studies should address other traits related to dairy farm profitability, including milk composition, female fertility, longevity, feed efficiency, and resistance to infectious and metabolic diseases.

Animals↗
PubMed2006

Effects of the signal transducer and activator of transcription 1 (STAT1) gene on milk production traits in Holstein dairy cattle.

A functional candidate gene approach was used to search for genes affecting milk production traits in Holstein dairy cattle. Signal transducer and activator of transcription 1 (STAT1) was chosen because of its involvement in the development of the mammary gland. Using the pooled genomic DNA sequencing approach, we identified a single nucleotide polymorphism. Genomic DNA was extracted from 1,292 sons obtained from the Cooperative Dairy DNA Repository and from 715 blood samples of daughters of 12 bulls obtained from the University of Wisconsin resource population. Daughter yield deviation data for the sons and yield deviation for the daughters were obtained for milk production traits from the USDA Animal Improvement Programs Laboratory. For the Repository population, allele C was associated with significant increases in milk fat and protein percentages. For the University of Wisconsin population, genotypes CC and CT were associated with significant increases in milk, fat, and protein yields. Results from this study are consistent with previous studies on the role of STAT1 in regulating the transcription of genes involved in milk protein synthesis and fat metabolism.

3' Untranslated Regions↗
PubMed2005

Association of the protease inhibitor gene with production traits in Holstein dairy cattle.

Positional, comparative candidate gene analysis and previous quantitative trait loci linkage mapping results were used to search for candidate genes affecting milk production and reproduction traits in dairy cattle. The protease inhibitor (PI) gene was chosen for examination, and 5 single nucleotide polymorphisms were detected in coding regions of the gene by direct sequencing of reverse transcription-polymerase chain reaction products from a wide range of cattle tissues. A total of 6 different intragenic haplotypes were identified in North American Holstein population, and these were examined for associations with milk production traits in 24 half-sib families comprising 1007 sons utilizing a granddaughter design. One common haplotype was associated with increased milk and fat yields, increased productive life, and decreased somatic cell score. Another common haplotype was associated with decreased productive life and increased somatic cell score. One rare haplotype was associated with decreased milk, fat, and protein yields and increased milk protein percentage; another rare haplotype was associated with decreased milk yield, increased protein percentage, and decreased productive life. The observation that the PI gene is associated with analogous traits in humans demonstrates the effectiveness of the positional comparative candidate gene analysis that utilizes information about genes present in chromosomal regions with conserved synteny in other species.

Animals↗
PubMed2005

Effects of the osteopontin gene variants on milk production traits in dairy cattle.

Osteopontin (OPN) is a highly phosphorylated glycoprotein whose gene has been cloned and sequenced in different species. Several whole genome scans have identified quantitative trait loci (QTL) affecting milk production traits on bovine chromosome 6 close to the osteopontin gene (OPN) location. The presence of OPN in milk and its elevated expression in mammary gland epithelial cells together with previous QTL studies have prompted us to investigate the effects of OPN variants on milk production traits in the Holstein dairy cattle population. A single nucleotide polymorphism in intron 4 (C/T) was detected and primers were designed to amplify genomic DNA from 1362 bulls obtained from Cooperative Dairy DNA Repository and from 214 cows from the University of Wisconsin herd. For the Repository population, the C allele was associated with an increase in milk protein percentage and milk fat percentage. Correlation between milk protein percentage and milk fat percentage was about 0.57. For the University of Wisconsin herd, the estimates of the effects of allele C were in the same direction as for the Repository population, although these estimates did not reach statistical significance. Our results are consistent with other studies that showed a significant association of the microsatellite markers in the region of OPN with milk protein percentage and other correlated traits.

Alleles↗
PubMed2000

Combined sciatic-paravertebral nerve block vs. general anaesthesia for fractured hip of the elderly.

Sixty elderly patients scheduled for surgical hip fracture repair were given the choice of either general isoflurane anaesthesia (n = 30) or a nerve stimulator guided combined sciatic-paravertebral nerve block (n = 30). The incidence of intraoperative hypotension and the need for postoperative admission to the intensive care unit/high dependency unit (ICU/HDU) within 48 hours postoperatively were recorded. No differences in patient characteristics, ASA class or concomitant disease status were detected between the two study groups. Both the incidence of intraoperative hypotension (0/30 vs. 11/30, p < 0.001) and the postoperative need for ICU/HDU admission (0/30 vs. 11/30, p < 0.001) was significantly reduced in patients treated with a combined sciatic-paravertebral nerve block compared to patient receiving general anaesthesia. The length of hospital stay was also found to be shorter for patient in the regional anaesthesia group [mean 6.7 days (SD 2.3) vs. 13.6 days (SD 6.1)]. The described technique appears to be an attractive alternative method to handle proximal fractures of the femur in the elderly, especially in a situation with limited ICU/HDU availability.

Aged↗
PubMed1999

[Advantages and disadvantages in the use of central venous catheters in children with malignant diseases].

The authors report the problem of central venous catheter appliance to the children with malignant diseases, employed for the first time in Bosnia and Herzegovina with the aim of pediatric oncologic patients treatment. During 1997 central venous catheter type Hickman was used in nine children between two and half to eleven years old (average six years and one months). The average time of catheter placement was six months, in two cases catheter were eliminated after two and three months respectively since application (spontaneous elimination and repeated septic attacks, caused bu resistant bacterial strains). Gram-positive bacteria have been isolated with eight children (Staphylococcus aureus and Staphylococcus epidermidis), and gram-negative enterobacteriaceae (Serratia marcescens, Pseudomonas aeruginosa, Klebsiella oxytocia and pneumoniae, Escherichia coli, Salmonella group C and Enterococcus faecalis) in samples taken from the catheter and hemoculture. The central venous catheter is useful in treating oncological patients, but may cause serious consequences, like local infections or septicaemia.

Anti-Bacterial Agents↗
PubMed1998

Research notes: Fresh and frozen pools of chicken red blood cells as substrates for direct polymerase chain reaction.

A method is presented for reliable use of pooled chicken blood samples for estimation of microsatellite frequencies by direct polymerase chain reaction (PCR) amplification of DNA. This method overcomes the variability of hematocrit values in individual chickens and eliminates the step of DNA preparation. The estimated frequencies of polymorphic alleles in fresh and frozen pooled blood samples were similar to those obtained by calculating these frequencies from the individual genotyping. When frozen pooled blood samples are used, pools should be prepared prior to their freezing.

Animals↗
PubMed1997

A PCR-based test for the presence of endogenous virus gene evA in chickens.

An endogenous virus, denoted evA, is present at high frequency in all brown egg layer lines. Using inverse polymerase chain reaction (PCR) based on the viral LTR regions, products were obtained containing cellular sequences 5' and 3' to the viral insertion point. PCR of chicken genomic DNA was carried out, using primers chosen from the 5' and 3' cellular sequences and a primer chosen from either the U3 or U5 portions of the viral LTR. Amplification of DNA from birds that did not carry evA with the primer triplets always gave a single 364 bp reaction product, interpreted as representing the flank-to-flank amplification product. Amplification of DNA from known homozygous or heterozygous evA carriers, with the same primer triplets, always gave both the expected junction product and 364 bp product. Therefore, these primer sequences can be used to distinguish evA carriers from non-carriers but cannot distinguish between homozygous and heterozygous evA carriers.

Alpharetrovirus↗
PubMed1997

The distribution of the vWF alleles and genotypes in the Palestinian population.

Short tandem repeat (STR) loci amplified by PCR are known as a useful tool for individual identification and paternity testing. Direct PCR amplification from small amounts of whole blood is a rapid and convenient method for population screening for STR and VNTR markers. The allele frequencies of the vWF locus were determined for 127 unrelated Palestinians. Co-dominant segregation was observed in 20 mother/child pairs. Nine alleles were observed, with frequencies ranging from 0.004 to 0.327. Heterozygosity was 79%, and discrimination power was 0.927.

Alleles↗
PubMed1995

Development of a genetic map of the chicken with markers of high utility.

Microsatellites are tandem duplications with a simple motif of one to six bases as the repeat unit. Microsatellites provide an excellent opportunity for developing genetic markers of high utility because the number of repeats is highly polymorphic, and the assay to score microsatellite polymorphisms is quick and reliable because the procedure is based on the polymerase chain reaction (PCR). We have identified 404 microsatellite-containing clones of which 219 were suitable as microsatellite markers. Primers for 151 of these microsatellites were developed and used to detect polymorphisms in DNA samples extracted from the parents of two reference populations and three resource populations. Sixty, 39, 46, 49, and 61% of the microsatellites exhibited length polymorphisms in the East Lansing reference population, the Compton reference population, resource population No. 1 (developed to identify resistance genes to Marek's disease), resource population No. 2 (developed to identify genes involved in abdominal fat), and resource population No. 3 (developed to identify genes involved in production traits), respectively. The 91 microsatellites that were polymorphic in the East Lansing reference population were genotyped and 86 genetic markers were eventually mapped. In addition, 11 new random amplified polymorphic DNA (RAPD) markers and 24 new markers based on the chicken CR1 element were mapped. The addition of these markers increases the total number of markers on the East Lansing genetic map to 273, of which 243 markers are resolved into 32 linkage groups. The map coverage within linkage groups is 1,402 cM with an average spacing of 6.7 cM between loci. The utility of the genetic map is greatly enhanced by adding 86 microsatellite markers. Based on our current map, approximately 2,550 cM of the chicken genome is within 20 cM of at least one microsatellite marker.

Animals↗
PubMed1994

Determining relative microsatellite allele frequencies in pooled DNA samples.

Accurate quantification of relative allele frequencies in pooled DNA samples can be carried out for microsatellite markers having a dinucleotide repeat unit, conditional on the absence of overlapping "shadow" bands. This provides a basis for extending DNA pooling to this useful class of DNA marker. Expressions for the standard error of densitometric estimates of allele frequencies from pooled samples are presented, and their statistical application is illustrated in a variety of situations. This enables DNA pooling to be utilized in situations requiring the testing of statistical hypotheses concerning differences in allele frequencies between populations, or samples.

Alleles↗