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Biomedical subjects

M Afzal

Publications and source records attributed to M Afzal.

At least 19 recordsLinked to original sources
PubMed2006

Hydrocarbon uptake by roots of Vicia faba (Fabaceae).

Vicia faba was grown in crude oil polluted soil and its roots were extracted for the detection and estimation of hydrocarbons. Saturated and unsaturated Aliphatic Hydrocarbons (AHs) ranging from C(22) to C(36) were identified in AHs fraction. However, PAHs were not present in the same extract. This could be due to the fact that PAHs being toxic compounds are not accumulated in the plant root extracts of V. faba grown in crude oil polluted soil. Three phytoalexins were identified and estimated by mass spectrometric analysis in the root extracts of V. faba. These three compounds are 2-t-butyl-4-(dimethyl benzyl) phenol, 2, 4-bis (dimethyl benzyl) phenol and 2,4-bis (dimethyl benzyl)-6-butyl phenol. These phenolics in V. faba are being reported for the first time. These compounds are presumably elicited as a direct stress on crude oil hydrocarbons on the roots of this plant.

Hydrocarbons↗
PubMed2006

A review of nearly two decades in an autologous blood programme: The rise and fall of activity.

Autologous blood donation (ABD) has been widely recommended. Data from one of the oldest hospital-based programmes in Canada describe both activities and drawbacks. Data were compared over the nearly two decades of activity that peaked in 1996. A 5-year review of recent activity showed that of the 2410 patients referred for consideration, 1823 (75.64%) were accepted into the programme. Surgical services requested 5825 units of autologous blood. Of these, 3147 units were donated by 1536 patients, 803 units were transfused in the operating room and 558 units were given postoperatively. In total, only 1361 units (43.25%) were transfused. The mean age of the patients was 58 years (median 61 years and mode 69 years). The haemoglobin concentrations before donation were significantly higher, averaging 145.2 g L(-1) before donation and 114.9 g L(-1) immediately before surgery, whereas at the time of discharge, the haemoglobin concentration averaged 126.2 g L(-1) (P = 0.0001) in transfused patients. Data from this well-established ABD programme indicate less than 50% overall utilization. The activity in the programme increased until 1996 following which it dropped progressively. The low haemoglobin concentration after surgery is of concern and should foster a transfusion algorithm for these patients.

Blood Donors↗
PubMed2005

Proposal for genetic characterisation of wild-type mumps strains: preliminary standardisation of the nomenclature.

Though mumps virus (MuV) is a monotypic virus, genetic variation between strains has been described. Viruses have been placed into genotypes designated A-L based on the nucleotide sequence of the small hydrophobic (SH) gene, which is the most variable gene in the mumps genome. Molecular characterisation of MuV is an important component of mumps surveillance because it can help identify the transmission pathways of the virus as well as distinguish between wild-type and vaccine strains. Here, we propose a standardized nomenclature and an analysis protocol for the genetic characterisation of mumps strains to facilitate expansion of molecular epidemiological studies. In addition to assigning standard reference strains for the recognized genotypes of MuV, a convention is proposed for naming for strains and criteria to designate a new genotype.

Humans↗
PubMed2005

CoQ9 potentiates green tea antioxidant activities in Wistar rats.

Green tea (Camellia sinensis), and CoQ(9 )when given to Wistar rats produced a partial reversal on reserpine induced oxidative stress and liver damage. Green tea, with its abundant polyphenol (-)Epigallocatechin 3-gallate (ECGC) and other catechins, is known for its antioxidative characteristics influencing lipid metabolism. Ubiquinone, abundant in heart muscle, is also a potent antioxidant with known effects in numerous pathologies. However the combined effect of ECGC and ubiquninone has not been reported. In the present study we found that green tea extract, when given in combination with CoQ(9) to Wistar rats subjected to oxidative stress, showed a statistically significant antioxidative effect. Liver cholesterol level in rats receiving combination treatment was also significantly lower than control or rats receiving green tea extract alone. Reserpine induced liver damage in Wistar rats was also partially reversed by a treatment of green tea extract when combined with CoQ(9). These results may have important clinical implications and may be extrapolated for the treatment of patients suffering from liver damage due to hepatitis B/C or liver cirrhosis.

Alanine Transaminase↗
PubMed2005

Studies on Bacillus stearothermophilus. Part IV. Influence of enhancers on biotransformation of testosterone.

The impact of chemical enhancers on the biotransformation of testosterone has been exploited. Application of crude cell concentrates to produce Bacillus stearothermophilus-mediated bioconversion of testosterone at 65 degrees C for 72 h has been examined. After incubation, the xenobiotic substrate was added to the concentrated whole cell suspensions. The enhancer molecules were included in the whole cell suspension. The resultant products, after extraction into an organic solvent, were purified by thin layer chromatography and identification was carried out through spectroscopic data. Five steroid metabolites 9,10-seco-4-androstene-3,9,17-trione, 5alpha-androstan-3,6,17-trione, 17beta-hydroxy-5alpha-androstan-3,6-dione, 3beta,17beta-dihydroxyandrost-4-ene-6-one and 17beta-hydroxyandrost-4,6-diene-3-one were identified as biotransformation products of testosterone. A possible biosynthetic route for these bioconversion products is postulated.

Biotransformation↗
PubMed2005

Synthesis and antibacterial activity of cephradine metal complexes : part II complexes with cobalt, copper, zinc and cadmium.

Cephradine, the first generation cephalosporin, is active against a wide range of Gram-positive and Gram-negative bacteria including penicillinase-producing Staphylococci. Since the presence of complexing ligand may affect the bioavailability of a metal in the blood or tissues, therefore, in order to study the probable interaction of cephradine with essential and trace elements present in human body, cephradine has been reacted with cobalt, copper, zinc and cadmium metal halides in L:M ratio of 2:1 in methanol and the products recrystallized from suitable solvents to pure crystals of consistent melting points. Infrared and ultraviolet studies of these complexes were carried out and compared with ligand. Magnetic susceptibility studies of these complexes were also carried out showing their paramagnetic behavior. From the infra red studies and elemental analysis of the complexes, it has been shown that the drug molecule serves as a bidentate ligand coordinating through both its carboxylate at C-3 and beta-lactam nitrogen and the metal having a square planar or octahedral geometry. To evaluate the changes in microbiological activity of cephradine after complexation, antibacterial studies were carried out by observing the changes in MIC (minimum inhibitory concentration) of the complexes and compared with the parent drug by measuring the zone of inhibition of complexes and compared with the parent cephalosporin against both Gram-positive and Gram-negative organisms. For MIC observation, serial dilution method was employed and zone series were determined by disk diffusion method. Our investigations reveal that formation of complexes results in decrease in antibacterial activity of cephradine and MIC values are increased.

Anti-Bacterial Agents↗
PubMed2004

Chronic orchidectomy does not influence the sensitivity of the pituitary somatotropes to varying doses of GHRH administered intravenously to the adult male rhesus monkey.

In the present study, the pituitary growth hormone (GH) response to graded doses of GH-releasing hormone (GHRH) was determined in intact (n = 3) and chronically orchidectomized (n = 3) adult rhesus monkeys (Mucaca mulatta). GHRH in doses of 0, 6.25, 12.5 and 25 microg/kg BW was infused through a teflon cannula implanted in the saphenous vein. Blood samples were collected 60 min before and 90 min after the injection of the neurohormone at 15 min intervals. All bleedings were carried out under ketamine hydrochloride anesthesia. The plasma levels of GH were determined by using AutoDELFIA time-resolved flouroimmunoassay, whereas plasma levels of testosterone and estradiol were determined using specific radioimmunoassay systems. The GH responses to GHRH were not significantly different between intact and chronically orchidectomized monkeys at any of the dose levels tested (p > 0.05). The administration of GHRH resulted in a significant (p < 0.05) stimulation of GH secretion at all the doses tested and in both the groups studied. In both intact and orchidectomized animals, the greatest response was observed at 6.25 microg/kg and no further increase was noted with the higher doses of GHRH. In conclusion, the present study suggests that chronic orchidectomy does not influence the sensitivity of the pituitary somatotropes to GHRH stimulation implying that the responsiveness of the pituitary somatotropes to GHRH is independent of testicular steroid modulation.

Analysis of Variance↗
PubMed2004

Diuretic and nephroprotective effect of Jawarish Zarooni Sada--a polyherbal unani formulation.

A number of drugs, both single and compound preparations are used widely in Tibb-e-Unani (Unani medicine) in the management of renal diseases. But such drugs mostly, have not been investigated for their described effects. Jawarish Zarooni Sada (JZS) is one such polyherbal preparation containing 15 ingredients, mainly described to be diuretic and nephroprotective. Therefore, in the present study ethanol and water extracts of JZS (300 mg each) were investigated for diuretic activity by measuring the total urine output over a period of 6h. Sodium and potassium level in urine sample was also estimated. Nephroprotective activity of JZS against gentamicin-induced nephrotoxicity was investigated by administering JZS along with high dose of gentamicin (40 mg/kg) and elevation of serum urea and serum creatinine was taken as the index of nephrotoxicity. JZS showed significant diuretic and nephroprotective effect.

Animals↗
PubMed2003

Studies on Bacillus stearothermophilus. Part III. Transformation of testosterone.

Bacillus stearothermophilus, a thermophilic bacterium isolated from the Kuwaiti desert, produced a variety of monohydroxy androstene derivatives and an oxidized product when incubated with exogenous testosterone for 24 h at 65 degrees C. The major metabolite was identified as androst-4-en-3,17-dione while minor metabolites included 6 alpha-hydroxyandrost-4-en-3,17-dione, 6 beta-hydroxyandrost-4-en-3,17-dione, 6 alpha-hydroxytestosterone, and 6 beta-hydroxytestosterone. These metabolites were purified by TLC and HPLC followed by their identification using (1)H- and (13)C-NMR and other spectroscopic data.

Biotransformation↗
PubMed2003

Accumulation of trace metals in aquatic insect Stenopsyche marmorata Navas transferred in streams.

Instar V larvae of the aquatic insect Stenopsyche marmorata were transferred between a noncontaminated site and a contaminated site and changes in the accumulation of nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb) in larvae were monitored for 30 days. Concentrations of the four metals rapidly increased or decreased within 10 days in the transferred larvae and approached concentrations of the native larvae living in the transfer sites. The accumulation of Ni and Cu in the larval body was very noticeable. The decreased Ni concentrations are represented by two exponential rate formulas, suggesting a biological half-life of 1.4 and 12.1 days. Under laboratory conditions, routes of Ni and Cu uptake were examined and Ni uptake was found to be mainly from food. However, larvae accumulated Cu from both food and water sources. In this case, the amount of metal uptake from food was more than that from water. The results of this indoor experiment are discussed and compared with the results of the transfer field experiment. Active biomonitoring of trace metal in transferred larvae is useful since it enables rapid and easy assessment of metal contamination.

Animals↗
PubMed2003

The immune response of guinea pigs and buffalo calves to the locally prepared Brucella abortus strain 19 vaccine.

Brucella abortus vaccine was prepared from strain 19 imported from Germany. The vaccine induced a good immune response in guinea pigs as evidenced by a serological titre of 328 international units (IU)/ml 10 days post-vaccination. Vaccinated guinea pigs also withstood an experimental challenge of 5,000 colony-forming units of a locally isolated virulent B. abortus strain. This vaccine, containing 7 x 10(10) viable organisms, induced a significant immune response in 8 to 10.5 month old female buffalo calves. Significant serum agglutination test (SAT) titres were seen on day 7 following vaccination. The highest SAT titres were observed on day 14 post-vaccination and the titres started declining thereafter. The rate of decrease was slow from day 14 to day 49 post-vaccination; however, a rapid decrease in titres was seen from day 49 to day 91 post-vaccination. Negligible SAT titres were observed on day 91 post-vaccination. Specific immunoglobulin G titres, as measured by 2-mercaptoethanol treated SAT, also followed a similar trend and the titre of all five of the calves that were vaccinated became zero on day 91 post-vaccination.

Animals↗
PubMed2003

The prevalence of silent kidney stones--an ultrasonographic screening study.

OBJECTIVE: Silent and not yet discovered stones of the upper urinary tract are potentially dangerous, since in due course they may cause infection, obstruction and renal damage. The aim of this study was to determine the prevalence of such silent kidney stones in a representative Pakistani population of Karachi. SUBJECTS AND METHODS: We studied 201 consecutive subjects at our hospital who underwent additional kidney screening whilst undergoing abdominal ultrasound. All these subjects did not have a history or symptoms of urolithiasis. RESULT: We found silent kidney stones in 3% of subjects. All stone bearers were males. Most stones were in the left kidney. Notably, multiple stones and stones of a considerable size went unnoticed. CONCLUSION: In addition to the usual figures of incidence and prevalence of stone disease drawn from patient data, there is a prevalence of 3% silent stones that may only be discovered incidentally or by screening. This is true for a "'stone country" like Pakistan. Figures for other regions have yet to be determined. Due to socioeconomic reasons, we believe that a general kidney screening for urolithiasis is, however, not indicated, at least in our country.

Adolescent↗
PubMed2003

Synthesis and antibacterial activity of cephradine metal complexes: part I complexes with magnesium, calcium, chromium and manganese.

Cephradine is included among the first generation cephalosporins, which is active against a wide range of Gram-positive and Gram-negative bacteria including penicillinase-producing Staphylococci. Since the presence of complexing ligand may affect the bioavailability of a metal in the blood or tissues, therefore, in order to study the probable interaction of cephradine with essential and trace elements present in human body, cephradine has been reacted with cobalt, copper, zinc and cadmium metal halides in L:M ratio of 2:1 in methanol and the products recrystallized from suitable solvents to pure crystals of consistent melting points. Infrared and ultraviolet studies of these complexes were carried out and compared with ligand. Magnetic susceptibility studies of these complexes were also carried out showing their paramagnetic behavior. From the infra red studies and elemental analysis of the complexes it has been shown that the drug molecule serves as a bidentate ligand coordinating through both its carboxylate at C-3 and beta -lactam nitrogen and the metal having a square planar or octahedral geometry. To evaluate the changes in microbiological activity of cephradine after complexation, antibacterial studies were carried out by observing the changes in MIC (minimum inhibitory concentration) of the complexes and compared with the parent drug by measuring the zone of inhibition of complexes against both Gram-positive and Gram-negative organisms. For MIC observation, serial dilution method was employed and zone series were determined by disk diffusion method. Our investigations reveal that formation of complexes results in decrease in antibacterial activity of cephradine and MIC values are increased.

Journal Article↗
PubMed2002

Studies on Bacillus stearothermophilus. Part II. Transformation of progesterone.

Bacillus stearothermophilus, a thermophilic bacterium isolated from Kuwaiti desert, when incubated with exogenous progesterone for 10 days at 65 degrees C produced two new dihydroxy isomers of progesterone, and two known compounds, 5 alpha-pregnane-3,6,20-trione and 6-dehydroprogesterone, along with the earlier reported monohydroxylated metabolites and a B-Seco compound. The two new dihydroxy compounds were identified as 6 alpha,20 alpha-dihydroxyprogesterone and 6 beta,20 alpha-dihydroxyprogesterone. These metabolites were purified by TLC and HPLC followed by their identification through 1H, 13C NMR and other spectroscopic data.

Biotransformation↗
PubMed2001

Evaluation of genotoxic potential of synthetic progestins-norethindrone and norgestrel in human lymphocytes in vitro.

The genotoxicity study of two widely used contraceptive synthetic progestins, i.e. norgestrel and norethindrone was carried out on human lymphocyte chromosomes using chromosomal aberrations (CA), sister chromatid exchanges (SCE) and cell growth kinetics as parameters. The study was carried out both in the presence as well as in the absence of metabolic activation (S(9) mix). The lymphocytes were exposed to three different concentrations of the drugs (20, 40 and 75 microg/ml for norethindrone and 10, 25 and 50 microg/ml for norgestrel) for three different durations (24, 48 and 72 h). The drug norethindrone was found to be non-genotoxic at any concentration and at any exposure duration either in the presence or in the absence of S(9) mix. But another drug norgestrel was found to affect the genetic material. It induces CA, SCE at significant level, and inhibits lymphocyte proliferation at 25 and 50 microg/ml of concentrations only. In the presence of S(9) mix the values obtained for CA, SCE and mitotic index (MI) were more significant. A time and dose relationship was also observed. It was concluded that norgestrel itself and possibly its metabolites are potent mutagens beyond a particular dose in human lymphocytes.

Cell Cycle↗