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Biomedical subjects

J Ali

Publications and source records attributed to J Ali.

At least 19 recordsLinked to original sources
PubMed2006

Complex genetic networks underlying the defensive system of rice (Oryza sativa L.) to Xanthomonas oryzae pv. oryzae.

Complete resistance (CR) and partial resistance (PR) of rice (Oryza sativa L.) to its bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo), was genetically dissected by using 2 mapping populations and 10 Xoo races. Two CR genes, 50 quantitative resistance loci, and 60 digenic interactions were identified, which showed various degrees of race specificity to the Xoo races. The complex epistasis between these loci led us to the discovery of complex genetic networks underlying the rice defensive system to Xoo. The networks consisted of two major components: one representing interactions between alleles at the R loci of rice and alleles at the corresponding avirulence loci of Xoo for CR and the other comprising interactions between quantitative resistance loci in rice and their corresponding aggressiveness loci in Xoo for PR. The race specificity of PR and its strong genetic overlap with CR indicate that PR is essentially "weaker" CR. The genetic networks discovered are expected to maintain a high level of the allelic diversity at avirulent loci in the pathogen by stabilizing selection, which may maintain a high allelic diversity at R loci in the host by the frequency-dependent selection.

Alleles↗
PubMed2006

Torsion and infarction of an accessory liver lobe.

Accessory lobes of the liver (ALL) may be congenital or acquired and are usually of no clinical significance. Torsions of the ALL are exceedingly rare and most are incidental findings at laparotomy, autopsy and in the course of investigation radiological investigations. A total of 17 infant and adult cases have been described previously in the medical literature. Most cases described since 1925 have been diagnosed at laparotomy, we report the 18th case of torsion of the accessory lobe of the liver in an elderly female which, despite all radiological interventions, required laparoscopy for diagnosis. We conclude that torsion of the accessory lobes of the liver is a rare finding; radiological imaging does not reveal the diagnosis and most are found at laparotomy. Laparoscopy may aid in the diagnosis of torsion of accessory liver lobes. If pain persists, we advocate the use surgical intervention with or without cholecystectomy.

Abdominal Pain↗
PubMed2006

Effect of succinylation of antibodies on their conformation and interaction with the antigen.

Using succinic anhydride, a succinylated derivative of anti-urease IgG having 49 +/- 6% modification was prepared and its physicochemical and immunological properties were studied. IgG undergoes substantial changes in its native conformation on succinylation, which was mainly attributed to electrostatic destabilization of the native protein conformation. The modified IgG exhibited a decrease in its cross-reactivity with urease. This decrease is attributed to the conformational change in IgG upon succinylation and/or is due to the disruption of the lysine residues in the antigen-binding site of IgG upon succinylation, which may be involved in binding the antigen. IgG was able to bind to the specific antigen although its conformation was partially modified. Therefore, partial modification of the conformation of the antigen-binding site of IgG is permissible in order to bind to the antigen.

Animals↗
PubMed2006

Formulation and development of gastroretentive drug delivery system for ofloxacin.

The aim of the present study was to develop a delivery system wherein the retention of ofloxacin could be achieved for increased local action in gastric region against Helicobacter pylori infection. The formulation was optimized on the basis of in vitro buoyancy and in vitro release in citrate phosphate buffer (pH 3). The hydrodynamically balanced capsules were prepared by physical mixing of various grades of HPMC and poly(ethylene oxide) (PEO) alone as well as in combinations. Cellulose acetate pthalate, liquid paraffin, and ethyl cellulose were used as release modifiers so as to maintain release of drug over a period of 12 h. The capsules prepared with PEOWSR 60K and drug coated with 2.5% ethyl cellulose gave the best in vitro percentage release and were taken as the optimized formulations. Various grades of Eudragit and PEO were used in combination for formulating floating microspheres using solvent diffusion technique for preparation of multiple unit system. The use of two different solvents (dichloromethane and ethanol) that differed in the rate of diffusion led to formation of a hollow core in the microspheres, which was partially responsible for the flotation ability. The in vitro release of the floating capsules and microspheres was found to be 96.02% and 95.83% in 12 h, respectively. Both the dosage forms follow Higuchi model for release from formulations. By fitting the in vitro release data of single unit dosage form into zero-order, first-order, and Higuchi model, it could be concluded that the release followed Higuchi model, as the correlation coefficient (R2 value) was higher than those in the other two release models. In both cases of single and multiple unit dosage form, R2 values for Higuchi model were found to be good, showing that drug release followed non-Fickian diffusion mechanism.

Administration, Oral↗
PubMed2006

Biodegradable periodontal intrapocket device containing metronidazole and amoxycillin: formulation and characterisation.

The purpose of the study was to formulate biodegradable intrapocket dental films, which could be easily placed into the periodontal pocket, and be capable of delivering therapeutic concentrations of amoxycillin and metronidazole for prolonged period of time with a much lower dose, hence obviating untoward side effects. A biodegradable intrapocket device containing amoxycillin and metronidazole was prepared using 69.29 mg each of amoxycillin and metronidazole, 2.0% diethyl phthalate plasticizer and 750 mg poly (L-lactide-co-glycolide). The device was optimized on the basis of evaluation parameters such as weight variation, content uniformity, surface pH, and in vitro and in vivo release studies. The films showed sustained in vitro release for a period of 16 days. In vivo release studies showed that drug concentrations were maintained above the MIC value for the entire period of the release studies. The samples from this study were capable of inhibiting the growth of most test strains. The combination of amoxycillin and metronidazole in the carrier polymer poly (L-lactide-co-glycolide) not only showed an extended spectrum of antimicrobial activity but also showed a synergistic effect against E. limosum, which had been reported the resistant to metronidazole in earlier studies. Stability studies were conducted on the optimized formulation and the degradation rate constant was found to be 4.6 x 10(-4)/day for metronidazole and 4.8 x 10-4)/day for amoxycillin. The drug was released locally and had a high benefit to low risk ratio as compared to systemic administration which is unacceptable due to, low benefit to high-risk ratio. Hence low-dose site-specific films present a better alternative.

Amoxicillin↗
PubMed2005

Stability-indicating HPTLC determination of curcumin in bulk drug and pharmaceutical formulations.

A simple, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of curcumin both as a bulk drug and in formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60 F-254 as the stationary phase. The solvent system consisted of chloroform:methanol (9.25:0.75 v/v). This system was found to give compact spots for curcumin (R(f) value of 0.48 +/- 0.02). Densitometric analysis of curcumin was carried out in the absorbance mode at 430 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r = 0.996 and 0.994 with respect to peak height and peak area, respectively, in the concentration range 50-300 ng per spot. The mean value +/- S.D. of slope and intercept were 1.08 +/- 0.01, 51.93 +/- 0.54 and 8.39 +/- 0.21, 311.55 +/ -3.23 with respect to peak height and area, respectively. The method was validated for precision, recovery and robustness. The limits of detection and quantitation were 8 and 25 ng per spot, respectively. Curcumin was subjected to acid and alkali hydrolysis, oxidation and photodegradation. The drug undergoes degradation under acidic, basic, light and oxidation conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and photo oxidation. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. As the method could effectively separate the drug from its degradation product, it can be employed as a stability-indicating one.

Calibration↗
PubMed2005

Genome-wide introgression lines and their use in genetic and molecular dissection of complex phenotypes in rice (Oryza sativa L.).

Tremendous efforts have been taken worldwide to develop genome-wide genetic stocks for rice functional genomic (FG) research since the rice genome was completely sequenced. To facilitate FG research of complex polygenic phenotypes in rice, we report the development of over 20,000 introgression lines (ILs) in three elite rice genetic backgrounds for a wide range of complex traits, including resistances/tolerances to many biotic and abiotic stresses, morpho-agronomic traits, physiological traits, etc., by selective introgression. ILs within each genetic background are phenotypically similar to their recurrent parent but each carries one or a few traits introgressed from a known donor. Together, these ILs contain a significant portion of loci affecting the selected complex phenotypes at which allelic diversity exists in the primary gene pool of rice. A forward genetics strategy was proposed and demonstrated with examples on how to use these ILs for large-scale FG research. Complementary to the genome-wide insertional mutants, these ILs opens a new way for highly efficient discovery, candidate gene identification and cloning of important QTLs for specific phenotypes based on convergent evidence from QTL position, expression profiling, functional and molecular diversity analyses of candidate genes, highlights the importance of genetic networks underlying complex phenotypes in rice that may ultimately lead to more complete understanding of the genetic and molecular bases of quantitative trait variation in rice.

Adaptation, Physiological↗
PubMed2004

Molecular inclusion of rofecoxib with cyclodextrin: pharmacological properties in laboratory animals.

Rofecoxib is practically insoluble in water and its prolonged use is associated with the incidence of side effects like gastrointestinal perforations, ulcerations and bleeding. Therefore, an attempt has been made to improve the aqueous solubility of the drug by making an inclusion complex using dimethyl-beta-cyclodextrin (DIMEB). The complexes were prepared by kneading and by the spray drying method. The prepared complexes showed better anti-inflammatory activity and decreased ulcerogenic potential than the pure drug.

Animals↗
PubMed2003

Molecular diversity and multilocus organization of the parental lines used in the International Rice Molecular Breeding Program.

One hundred and ninety three parental lines obtained from 26 countries for an international rice molecular breeding program were evaluated using 101 well-distributed simple sequence repeat (SSR) markers. An overall genetic diversity of 0.68 and an average of 6.3 alleles per locus were revealed, indicating a high level of genetic variation in these lines. Cluster analysis of the 193 accessions showed three major groups and nine subgroups. Group I corresponded to the classical indica subspecies, whereas groups II and III belong to the japonica subspecies. Indica and japonica differentiation accounted for only 6.5% of the total variation in the entire sample and 93.5% was due to within-subspecies diversity. Differentiation among eco-geographic regions accounted for 24% of the diversity within the subspecies. Larger amounts of the eco-geographical differentiation were resolved within japonica than within indica. The largest indica-japonica differentiation based on the single locus level was detected by markers on chromosomes 9 and 12, while the smallest differentiation was detected by markers on chromosomes 4 and 8. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between indica and japonica and among the main geographic regions. The multilocus analysis in genetic diversity showed a higher proportion of variation caused by predominant non-random associations of different loci within and among the classified subspecies and geographic subdivisions. The results suggest that selection for eco-geographical adaptation on multilocus associations was largely responsible for the maintenance of the extensive variation in the primary gene pool of rice.

Alleles↗
PubMed2003

Targeted retentive device for oro-dental infections: formulation and development.

Fibers loaded with amoxycillin trihydrate were prepared for oro-dental infections using melt spinning technique. Ethylene vinyl acetate, a biocompatible polymer was used for providing controlled release effect over a period of several days. The fibers were evaluated for in vitro release in alkaline borate buffer pH 8.1 in a biological shaker which was rotated at 50 rpm at 37 degrees C. In situ studies were carried out in continuous flow through apparatus which simulated the conditions of periodontal pocket. Microbiological evaluation was carried out on strains commonly implicated in oro-dental infections namely S. aureus, S. mutans, and Bacteroides cereus. Results of in vitro release studies revealed that the effect was sustained over a period of 6 days and followed Fickian diffusion mechanism. In situ release study samples were well above the minimum inhibitory concentration of the drug. These samples were effective in inhibiting the growth of the above-mentioned strains. The optimized formulation was characterized for general appearance, content uniformity, and SEM. Stability studies carried out on the formulation showed the degradation rate constant value of 2.79 x 10(-4) per day. Retentive fibers were found to be very effective in controlled delivery of amoxycillin, and hence can be feasible alternative to systemic administration.

Amoxicillin↗
PubMed2003

Routine laser assisted hatching results in significantly increased clincal pregnancies.

PURPOSE: To elucidate the appropriateness of current indications for assisted hatching (AH) in cleavage stage human embryos and to confirm our preliminary findings that only young patients (about 67%) benefit from AH. METHODS: Prior to transfer, 2 of 3 embryos selected for ET were subjected to laser assisted hatching (LAH). Control group consisted of patients matched by similar characteristics and protocol except LAH was not performed. RESULTS: The clinical pregnancy rate in women < or = 36 years was 64.9% (24/37) for embryos subjected to LAH but was significantly lower (p = 0.029) in the control (33.3%; 10/30). The implantation rate in women < or = 36 years in the test group was 38.1% (40/105) that was significantly higher than that of the control group (17.5%, 14/80; p = 0.0039). CONCLUSIONS: LAH is beneficial for women < or = 36 years but not for women > or = 37 years, for embryos with thin zonae (< or = 16 micron) but not with thick zonae (> or = 17 micron), and for those with repeated failures (37-50%).

Adult↗
PubMed2003

Improving medical undergraduate trauma education through the Trauma Evaluation and Management programme at Mona.

This study examines the potential role of the Trauma Evaluation and Management (TEAM) programme in the undergraduate curriculum for medical students in Jamaica. Thirty-two final year medical students were randomly assigned to two groups of 16. One group (No TEAM) completed two 20-item multiple choice question (MCQ) examinations on trauma resuscitation topics. The second group (TEAM group) completed the first 20-item MCQ. The TEAM manual was then distributed to both groups. After the TEAM programme for both groups, the TEAM group had the second MCQ examination. Unpaired "t" tests were used for in-between group and paired "t" tests for between group comparisons with p < 0.05 being considered statistically significant. Both groups completed a post-course questionnaire rating five items on a scale of one to five. The No TEAM group showed no difference in mean scores between the 1st and 2nd tests (55.3% in the 1st test to 52.2% in the 2nd test, p = 0.32). The TEAM Group improved their MCQ scores from 53.1% pre-module to 69.4% post-module (p < 0.001). A score of four of five was assigned by 28 students for the statement that the objectives were met, that trauma knowledge was improved and that there was overall satisfaction; by 17 students that clinical trauma skills were improved and 29 students that TEAM should be mandatory in the undergraduate curriculum. The TEAM programme improved trauma knowledge skills among senior medical students in Jamaica. The questionnaire results suggested enthusiasm for the programme and that it be made mandatory in the senior undergraduate medical curriculum.

Clinical Competence↗
PubMed2003

Effect of dental films containing amoxycillin and metronidazole on periodontal pathogens: microbiological response.

Biodegradable dental films containing a combination of amoxycillin and metronidazole were prepared by a dispersion method. The aim of the present study was to determine the antimicrobial activity of this formulation against the pathogens which are commonly implicated in periodontal infections. Films showed sustained release in vitro for a period of 16 days. In situ release studies carried out using fresh bovine buccal mucosa in a flow through cell, showed that drug concentrations were maintained above MIC values for the entire period of the release studies. Samples from these studies were capable of inhibiting the growth of most of the test strains. The combination of amoxycillin and metronidazole using carrier polymer poly-L (lactide co-glycolide) not only showed an extended spectrum of antimicrobial activity but also showed a synergistic effect against Eubacterium limosum, which had earlier been reported resistant to metronidazole.

Absorbable Implants↗
PubMed2003

Potential role for advanced trauma life support programme in improving trauma care in Jamaica.

Data from the Road Safety Unit in the Ministry of Transport and Works, Jamaica, show an increase in road traffic accidents from 7861 in 1991 to 11,010 in 1999. The average number of deaths annually was 380 +/- 48 (SD) while injuries averaged 3320 +/- 262 per year. This represents an injury to death ratio of 8.7 compared with 24.9 for Trinidad and Tobago and 40 for Canada. During the period 1991 to 2000, an average of 796 +/- 159 (SD) murders were committed annually. The number of murders increased by over 280 per cent between the decade of the seventies and the nineties. Data from the trauma registry of the University Hospital of the West Indies showed that 29.6 per cent of all admissions to the surgical ward between January 1998 and December 31, 2000, were due to injuries. There were 97 deaths (3%) during this period and 33 occurred in the Accident and Emergency Department with 70 per cent occurring within 120 minutes of their arrival. The Advanced Trauma Life Support (ATLS) Programme emphasizes the resuscitation and stabilization of injured patients in the first few hours after injury. Most Emergency Departments in Jamaica are staffed by relatively junior medical officers and the low injury to death ratio among victims of motor vehicle accidents may be due to suboptimal care. Introduction of an ATLS programme in Jamaica may reduce the number of preventable deaths and also stimulate interest in trauma care thus increasing preventative measures to decrease the high incidence of trauma in Jamaica.

Accidents, Traffic↗
PubMed2002

Buccoadhesive erodible disk for treatment of oro-dental infections: design and characterisation.

Buccoadhesive erodible disks of cetylpyridinium chloride were prepared using different bioadhesive polymers along with excipients like mannitol. The purpose of designing the erodible disk was to obviate the need for removal of exhausted device. The optimized disk containing 5.0 mg of cetylpyridinium chloride, 2.0 mg of magnesium stearate and 6.0 mg of mannitol along with sodium carboxy methyl cellulose DVP and hydroxypropylmethylcellulose K4M in the ratio of 1:3 was found to release the drug for a period of over 6.0 h without getting dislodged. Maximum in vitro drug release was found to be 94.78% in 6.0-h study. In situ release characteristics were evaluated using a 'flow-through assembly', which simulated the conditions of the human buccal cavity. The drug concentrations in the in situ samples were found to be above minimum inhibitory concentration (MIC) of the drug. The bioadhesive performance and the surface pH of the disks were satisfactory. Cetylpyridinium chloride disks were tested against microorganisms commonly found in oro-dental infections namely Candida albicans, Staphylococcus aureus, Escherichia coli and Streptococcus mutans. The disk as well as the in situ samples showed inhibition of growth of microorganisms. Approval was taken from Jamia Hamdard Review Board (Ethical Board) to perform in vivo studies in healthy human volunteers. In vivo evaluation of buccoadhesive disks revealed adequate comfort, taste, and non-irritation and none of the volunteers reported severe dry mouth/severe salivation or heaviness at the place of attachment. Salivary concentrations were maintained above MIC for 8.0 h. Correlation was found between the drug concentration in situ and concentration of drug in saliva collected in healthy human volunteers. The correlation was found to be positive with a correlation coefficient of 0.9596. It was found to be statistically significant at 5% confidence level (P<0.05).

Adhesives↗
PubMed2001

Complete genome sequence of Salmonella enterica serovar Typhimurium LT2.

Salmonella enterica subspecies I, serovar Typhimurium (S. typhimurium), is a leading cause of human gastroenteritis, and is used as a mouse model of human typhoid fever. The incidence of non-typhoid salmonellosis is increasing worldwide, causing millions of infections and many deaths in the human population each year. Here we sequenced the 4,857-kilobase (kb) chromosome and 94-kb virulence plasmid of S. typhimurium strain LT2. The distribution of close homologues of S. typhimurium LT2 genes in eight related enterobacteria was determined using previously completed genomes of three related bacteria, sample sequencing of both S. enterica serovar Paratyphi A (S. paratyphi A) and Klebsiella pneumoniae, and hybridization of three unsequenced genomes to a microarray of S. typhimurium LT2 genes. Lateral transfer of genes is frequent, with 11% of the S. typhimurium LT2 genes missing from S. enterica serovar Typhi (S. typhi), and 29% missing from Escherichia coli K12. The 352 gene homologues of S. typhimurium LT2 confined to subspecies I of S. enterica-containing most mammalian and bird pathogens-are useful for studies of epidemiology, host specificity and pathogenesis. Most of these homologues were previously unknown, and 50 may be exported to the periplasm or outer membrane, rendering them accessible as therapeutic or vaccine targets.

Animals↗
PubMed2001

Comparison of performance 2 years after the old and new (interactive) ATLS courses.

BACKGROUND: We previously (1997) demonstrated superior clinical but similar cognitive performance after the new interactive compared to the old ATLS course. The present study is aimed at determining whether this difference was short term or maintained over time (2 years). MATERIALS AND METHODS: Two groups of 13 physicians out of the original 32 physicians were available for the study which compared performance in a 40-item MCQ examination on trauma topics and clinical performance in 4 trauma OSCE stations consisting of simulated trauma patients. Paired and unpaired t tests were used for within- and between-group comparisons, respectively, with P < 0.05 being considered statistically significant. Overall OSCE scores (maximum standard 20), adherence to priority scores (Priority, scale 1 to 7), and overall approach (Approach, scale 1 to 5) scores were analyzed. RESULTS: Values are means +/- SD; (+)-P < 0.05 compared to 1999; *P < 0.05 compared to old group [table in text]. CONCLUSIONS: Although knowledge base decreases similarly with time after both courses, the new interactive course participants maintained a consistently higher clinical skill performance level at 2 years.

Cognition↗