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Biomedical subjects

M Arif

Publications and source records attributed to M Arif.

At least 55 records · Page 3Linked to original sources
PubMed1998

Identification of a commonly deleted region at 17p13.3 in leukemia and lymphoma associated with 17p abnormality.

Fluorescence in situ hybridization (FISH) was performed in 17 myeloid leukemia patients and seven lymphoid leukemia/ lymphoma patients who exhibited chromosomal abnormalities on the short arm of chromosome 17, in order to detect a commonly deleted region on chromosome band 17p13. Twenty-four leukemia/lymphoma patients studied cytogenetically at our institution over a period of 10 years had detectable 17p abnormalities such as translocation (six patients), addition (11 patients) and deletion of 17p13 (seven patients). A 17p abnormality was the only abnormality present in three patients. Most of the patients had additional complex cytogenetic abnormalities. The diagnosis was acute myeloid leukemia (AML) in 10 patients, two each with chronic myeloid leukemia (CML), acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL) and myelodysplastic syndrome (MDS) and the remaining three with malignant lymphoma (ML). Seven cosmid probes (D17S34, cCI17-624, cCI17-453, D17S379, cCI17-636, cCI17-732 and TP53) which mapped on 17p13 were used to analyze the allelic deletion. Eighty percent (19 out of 24) of the informative leukemia patients exhibited allelic loss in 17p13.3 at cC17-624. The smallest region of an overlapping deletion was observed on chromosome band 17p13.3 between cCI17-624 and cCI17-453. Patients with translocation involving 17p also showed deletion at cCI17-624 and cCI17-453. We hypothesize that this region contains a novel tumor suppressor gene(s) that is involved in leukemogenesis.

Adult↗
PubMed1998

Seroprevalence of human T-lymphotropic virus type I (HTLV-I) in Saudi Arabia.

During the past 6 years, blood donors at various hospitals and blood banks in Saudi Arabia have been screened by enzyme immuno-assay for antibodies to human T-lymphotropic virus type I (anti-HTLV-I). Seropositivity for anti-HTLV-I, clearly confirmed by western blot, was only demonstrable in three out of the 34,541 subjects (including at least 21,000 Saudi nationals). The three positives were all expatriates: two Indians and one Syrian. Another six subjects, who gave ambiguous reactions on western blots and may also have been positive, were also all expatriates. Saudi Arabia therefore appears to be a non-endemic area for HTLV-I and hence the current practice of screening all blood donors for anti-HTLV-I does not seem to be cost-effective. An alternative strategy, in which only expatriate blood donors are screened, should perhaps be considered by the Saudi Ministry of Health.

Adult↗
PubMed1998

Association of sequences in the coat protein/readthrough domain of potato mop-top virus with transmission by Spongospora subterranea.

A monofungal culture of Spongospora subterranea was unable to acquire and transmit the T isolate of potato mop-top pomovirus (PMTV-T), which has been maintained by manual transmission in the laboratory for 30 years. A recently obtained field isolate (PMTV-S) was efficiently acquired and transmitted by the same fungus culture. Sequence analysis of the readthrough (RT) protein-coding region of PMTV-S showed the presence of an additional 543 nt in the 3' half of the coding region relative to that of PMTV-T. These additional nucleotides preserved the reading frame of the RT protein and inserted 181 amino acids into the RT protein. This was confirmed by a comparison by immunoblotting of the sizes of the RT protein of PMTV-T and other recent isolates of PMTV.

Amino Acid Sequence↗
PubMed1998

Viscosity studies on Mestranol.

The viscosity of 1x10(-4) M to 4x10(-4) M solution of Mestranol (synthetic oestrogenic steroidal hormone) in ethanol was measured at 32 degrees, 40 degrees and 50 degrees C in a viscometric bath. The viscosity rates are maximum at 30 degrees C as compared to 40 degrees and 50 degrees C. The disappearance rate of Mestranol at higher temperature and lower viscosity is due to triplet state of species transitions at higher thermal conditions.

Journal Article↗
PubMed1998

Platelet Activating Factor antagonists.

Platelet Activating Factor (PAF) is a D-glycerol derived phosopholipid which is a potent endogenous mediator of inflammation. PAF is synthesized and released by a variety of cell types and elicits its biological activity by interacting with specific G-protein coupled receptors found on platelets, neutrophils, and other inflammatory cells. The physiological consequences of the interaction on PAF with its receptor include an increase in vascular permeability, hypotension, bronchoconstriction, and platelet and neutrophil aggregation. These biological effects are consistent with the concept that PAF is involved in a number of inflammatory diseases such as septic shock and asthma (Arimura A., 1998). Given the potent pathophysiological effects of PAF, a great deal of effort has been focused on the discovery of agents which block the action of PAF at its receptor. Within the past 10 years, a wide range of structures have been identified as PAF antagonists. These include not only PAF analogs, but also antagonists derived form natural product as well as non-lipid synthetic compounds. Several theories have been proposed to unify these diverse structural classes, but sophisticated molecular models of the receptor have not been widely employed (Braquet P., 1987). The discovery of new PAF antagonists has relied heavily on traditional medicinal chemistry approaches. A number of PAF antagonists have advanced to clinical evaluation. While several early compounds demonstrated efficacy in animal models of asthma they have failed to provide benefit for this condition in man. The current generation of potent antagonists are being evaluated as therapies for sepsis, pancreatitis and other disorders (Braquet C., 1991).

Journal Article↗
PubMed1997

Frequent jumping translocations of chromosomal segments involving the ABL oncogene alone or in combination with CD3-MLL genes in secondary leukemias.

Seven secondary leukemia patients were treated for solid tumors or malignant lymphoma with anticancer drugs or radiation. We studied bone marrow samples from these patients by fluorescence in situ hybridization (FISH). Of the seven patients, three had increased signals for the ABL oncogene (9q34) on interphase nuclei and at metaphase. One of the three patients also had four signals for the CD3 (MLL) region (11q23). Whole painting probes revealed that these chromosomal regions were translocated onto structurally abnormal chromosomes, resulting in partial tri-, tetra- or penta-somy of these regions. We called this type of translocation "segmental jumping translocation (SJT)." SJT of the ABL oncogene was not detected in samples from 15 patients with de novo acute myelocytic leukemia (AML), 12 with myelodysplastic syndrome (MDS), or 20 with chronic myelocytic leukemia (CML) at the chronic phase. Furthermore, monosomy 7 was also found in the patients with the gene amplification. These results indicate that SJT of ABL and/or CD3 (MLL) genes is associated with the leukemogenesis of secondary leukemia. The SJT may be one mechanism of gene amplification.

Aged↗
PubMed1997

Application of fluorescence in situ hybridization to detect residual leukemic cells with 9;22 and 15;17 translocations.

We performed fluorescence in situ hybridization (FISH) upon 9;22 and 15;17 translocation-positive bone marrow cells to monitor the clinical course of 46 patients with chronic myelocytic leukemia (CML) and nine with acute promyelocytic leukemia (AML M3) who received chemotherapy and/or bone marrow transplantation (BMT). M-BCR-ABL and PML-RAR alpha probes were used to detect translocations of t(9;22) and t(15;17), respectively. Signals from CML patients treated with interferon (17 patients) or BMT (29 patients) were 0.5-15% positive for the 9;22 translocation. Among nine M3 patients who received extensive chemotherapy or BMT, 1-5% were positive for the 15;17 translocation. A highly sensitive FISH procedure using both translocation probes and a whole chromosome Y probe was established and applied to eight sex-mismatched BMT patients (seven CML and one AML M3), in which 0.1-0.6% of signals positive for the specific translocations were detected. These results suggested that interphase FISH is powerful enough to identify minor cell populations of 9;22 or 15;17 translocations after therapy, as well as to detect specific chromosome abnormalities at diagnosis.

Bone Marrow↗
PubMed1997

Detection of residual host cells in sex-mismatched bone marrow transplantation in various hematological diseases by fluorescence in situ hybridization.

Thirty-eight sex-mismatched bone marrow transplantation patients with various hematological diseases were followed-up using fluorescence in situ hybridization. Probes specific for various translocations, the X chromosome (DXZ1) and the whole Y chromosome (WCP Y), were used to assess successful engraftment and residual host cells. The combination of translocation and WCP Y probes enabled the identification of host and donor cells in addition to the identification of malignant vs. normal cells in the transplant recipient. Fifteen patients were sequentially followed up. The results obtained using the combination of translocation plus WCP Y probes were more reliable than those with DXZ1 plus WCP Y probes, or the translocation probe alone, especially when the percentage of residual leukemic cells detected by the translocation probe alone was around the cut-off level.

Bone Marrow Transplantation↗
PubMed1997

Physiological analysis to quantify training load in badminton.

OBJECTIVE: To estimate the training load of specific on court training regimens based on the magnitude of variation of heart rate-lactate response during specific training and to determine the magnitude of variation of biochemical parameters (urea, uric acid, and creatine phosphokinase (CPK)) 12 hours after the specific training programme so as to assess training stress. METHODS: The study was conducted on six national male badminton players. Maximum oxygen consumption (VO2), ventilation (VE), heart rate, and respiratory quotient were measured by a protocol of graded treadmill exercise. Twelve training sessions and 35 singles matches were analysed. Heart rate and blood lactate were monitored during technical training routines and match play. Fasting blood samples collected on two occasions--that is, during off season and 12 hours after specific training--were analysed for serum urea, uric acid, and CPK. RESULTS: Analysis of the on court training regimens showed lactate values of 8-10.5 mmol/l in different phases. The percentage of maximum heart rate ranged from 82% to 100%. Urea, uric acid, and CPK activity showed significant changes from (mean (SD)) 4.93 (0.75) mmol/l to 5.49 (0.84) mmol/l, 0.23 (0.04) to 0.33 (0.06) mmol/l, and 312 (211.8) to 363 (216.4) IU/l respectively. CONCLUSION: Maximum lactate reported in the literature ranges from 3-6 mmol/l. Comparatively high lactate values and high percentage of maximum heart rate found in on court training show a considerable stress on muscular and cardiovascular system. The training load needs appropriate monitoring to avoid over-training. Workouts that are too intensive may interfere with coordination, a factor that is important in sports requiring highly technical skill such as badminton.

Adult↗
PubMed1997

Clonal identification of trisomies 3, 5 and X in angioimmunoblastic lymphadenopathy with dysproteinemia by fluorescence in situ hybridization.

Trisomies 3, 5 and X in six Japanese patients with AILD were detected by fluorescence in situ hybridization (FISH). Trisomies 3 and X were detected using centromeric probes. Cosmid probes locating on 5q31.1, the commonly deleted region, was used to detect trisomy 5. FISH detected three patients with trisomy 3 alone, one with trisomy 5 alone and one with all the three trisomies analysed. The sample that showed all three aberrations was further analysed by dual color FISH. The three trisomies were present on different cells. The AILD cells with trisomy 5 tended to replicate slowly, whereas those with trisomy 3 seem to have a proliferative advantage. An increase in the histopathological stage was reflected in the increase in the percentage of trisomy 3 cells in one patient.

Aged↗
PubMed1997

Pharmacological evaluation of newly synthesized piperidinium derivatives for their analgesic activity.

Two chemically synthesized piperidinium derivatives i.e l-methyl-1-(3,4) dihydroxy phenacyl-4-hydroxy piperidinium chloride and 1-methyl-(4-p) methoxy phenacyl 4-hydroxy piperidinium bromide have been evaluated for their analgesic activity in intact albino mice by tail immersion method because of their structural similarity with opioids. Both the compounds were administered in the doses of 50 mg/kg. The results were compared with pethidine used as the reference drug. The control animal received only the vehicle. The present study suggested that both the compounds exhibit significant analgesic activity.

Journal Article↗
PubMed1996

Hidden monosomy 7 in acute myeloid leukemia and myelodysplastic syndrome detected by interphase fluorescence in situ hybridization.

Fifty patients [25 acute myeloid leukemia (AML) and 25 myelodysplastic syndrome (MDS)], without monosomy 7 according to conventional cytogenetics, were re-examined by fluorescence in situ hybridization (FISH). Eleven (44.0%) patients with AML and nine (36.0%) with MDS showed hidden monosomy 7. Two samples who had both monosomy 7 and iso chromosome 17 were analyzed by dual color FISH to identify their clonal origin, and showed that these two abnormalities can occur together or independently. Only one of 16 MDS patients without monosomy 7 transformed into AML whereas four of eight MDS patients with the hidden monosomy 7 transformed into AML, suggesting patients with this abnormality are more likely to undergo transformation to AML.

Adult↗
PubMed1996

Cytogenetic and molecular genetic studies on Indian patients with chronic lymphocytic leukemia.

This is the first cytogenetic and molecular genetic study to find any specific genetic abnormalities in Indian patients with chronic lymphocytic leukemia (CLL). Cytogenetic studies on 18 patients indicated that their karyotypes were relatively simple and trisomy 12 was seen on karyotype evolution in one patient. Fluorescence in situ hybridization (FISH) revealed abnormal clones of trisomy 12 in nine cases and RB gene deletion in 14 of the 29 cases analyzed. Three patients had both clones. Immunoglobulin genes were rearranged in all the cases and TCR beta in none of the 18 cases Southern blotted. BCL-1 was rearranged in one case. No rearrangement of BCL-2 gene was seen in any case. Genetic changes in Indian CLL were more similar to Western CLL than to Japanese CLL, even though India is supposed to be a low incidence area. Therefore, factors (such as HLA and other genetic markers) other than these routine parameters must be studied to explain the low incidence of CLL in India.

Aged↗
PubMed1996

Enterically transmitted hepatitis in Saudi Arabia: an epidemiological study.

Rates of exposure to two, enterically transmitted viruses, hepatitis E virus (HEV) and hepatitis A virus (HAV), were investigated among the populations of two areas of Saudi Arabia: Gizan (a rural area) and Riyadh (an urban area, with relatively good sanitation). In Riyadh, 24.7% and 1.2% of children were seropositive for HAV and HEV, respectively, by the age of 12 years. There was a sharp increase in exposure to HAV between 13 and 20 years of age (to 63.5%) and most (80.0%) of the subjects aged 50 years had apparently been exposed to HAV. Although seropositivity to HEV also increased with subject age, it only reached 18.8% (in subjects aged > 50 years). The age-specific patterns of exposure to HAV and HEV in Gizan were similar to those in Riyadh but the rates of exposure were generally higher; mean rates of exposure to HAV and HEV were 76.3% and 14.9% in Gizan and 61.3% and 8.37% in Riyadh, respectively. That rates of exposure to HEV in Gizan were almost twice those in Riyadh emphasizes the importance of sanitation as an effective measure in controlling the spread of HEV in developing countries.

Adolescent↗
PubMed1996

Risk of hepatitis C virus infection among household contacts of Saudi patients with chronic liver disease.

To evaluate the intrafamilial transmission of hepatitis C virus and related risk factors among the Saudi population, two groups were investigated: 1) 20 index patients with chronic liver disease and their 127 family contacts, and 2) 20 blood donors who were anti-HCV-positive but with no chronic liver disease and their 91 family contacts. After a questionnaire on the risk factors for parenteral exposure, blood samples were obtained and tested for liver biochemistry and antibody to HCV (anti-HCV) by a third-generation enzyme immunoassay (UBI HCV EIA4.0). Only two spouses of 20 index patients were anti-HCV-positive while the remaining 125 family contacts were anti-HCV-negative. None of the 91 family contacts of the 20 anti-HCV-positive blood donors was anti-HCV-positive. The two spouses were wives of index patients but had a history of blood transfusion on at least two different occasions. Our results clearly indicate the intrafamilial transmission of HCV is not the route of transmission of HCV among Saudis and our results argue against sexual transmission of hepatitis C virus despite a relatively long duration of marriage.

Adult↗
PubMed1995

Profile of hepatitis C virus and the possible modes of transmission of the virus in the Gizan area of Saudi Arabia: a community-based study.

The seroprevalence of antibody to hepatitis C virus (anti-HCV) and the possible modes of transmission of HCV were investigated in Gizan, southern Saudi Arabia. The sample size chosen to give an adequate estimate of the seroprevalence, about 1500, was based on the assumption that 5% of the population in Gizan were anti-HCV-positive. Sera from 1482 subjects (705 males, 777 females; aged > or = 10 years) were initially screened for anti-HCV using a commercial, ubiquitin-based enzyme immunoassay. Repeatedly reactive sera were confirmed positive using second-generation immunoassays. Serum samples were also tested by ELISA for hepatitis B surface antigen (HbsAg) and antibodies to this antigen and to the hepatitis B core antigen. Of the subjects tested, 27 (1.8%) were anti-HCV-positive. Exposure to HCV was generally similar in both sexes, age-prevalence curves for anti-HCV peaking in males aged > 49 years (6.2%) and in females aged 40-49 years (5.0%). In the youngest subjects, those aged 10-19 years, the HbsAg carrier rate was significantly higher in males (10.4%) than in females (3.6%). Exposure to the hepatitis B virus was similar in both sexes (31.0% in males v. 28.6% in females). Some 7.4% and 14.8% of the 27 anti-HCV-positive cases had histories of schistosomiasis and blood transfusion, respectively. The corresponding values for the 1455 anti-HCV-negative cases investigated, 1.1% for schistosomiasis and 3.5% for blood transfusion, were much lower. The spouses and other family members of eight anti-HCV-positive index cases were investigated but none was anti-HCV-positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗