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Biomedical subjects

M S Ali

Publications and source records attributed to M S Ali.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Direct agglutination test for diagnosis and sero-epidemiological survey of kala-azar in the Sudan.

132 patients with suspected kala-azar (visceral leishmaniasis) were included in a prospective study to compare the performance of the direct agglutination test (DAT) with smears of lymph node, bone marrow and splenic aspiration. A titre greater than 1:3200 was considered positive. 67 patients provided positive smears and 65 were smear-negative. Compared with the results obtained from smears, the sensitivity of the DAT was 94% and its specificity 72%. Of 18 patients who were negative by smears but positive by DAT, 3 were treated on strong clinical suspicion of kala-azar and responded well to therapy. One other patient had post-kala-azar dermal leishmaniasis. Of the remaining 14, 8 were tested with the leishmanin skin test; 6 gave a positive result, suggesting past or sub-clinical infection. In 4 smear-positive patients, the DAT was negative; in 2 of these, the test remained negative during 6 months' follow-up. In a sero-epidemiological survey in a camp for displaced people, 30 of 600 sampled individuals gave a positive DAT. Of these, 11 had been treated for kala-azar; 4 others were leishmanin positive. The DAT is a useful screening test (sensitivity 94%; predictive value of a negative test 92%), but it does not differentiate between past kala-azar, sub-clinical infection and active disease.

Agglutination Tests↗
PubMedDate not supplied

Kala-azar in displaced people from southern Sudan: epidemiological, clinical and therapeutic findings.

Six hundred and ninety-three patients with kala-azar were seen in Khartoum, Sudan, from January 1989 to February 1990. They were almost exclusively from the Nuer tribe, originating from the western Upper Nile province in southern Sudan, an area not known previously to be endemic for kala-azar. Because of the civil war in southern Sudan no treatment was available locally and massive migration to northern Sudan occurred; many died on the way. All age groups were affected; there was a slight male preponderance (56%). In the clinical presentation, marked generalized lymphadenopathy was prominent (84%). Splenomegaly was absent in 4% of cases. Patients usually showed anaemia, leucopenia and/or thrombocytopenia. 623 patients were treated with sodium stibogluconate, 10 mg/kg for 30 d; relapse occurred in 4% and death in 12%. Latterly, 70 patients were treated with sodium stibogluconate at 2 x 10 mg/kg for 15 d, with relapse in 6% and death in 6%. The difference between the 2 regimens in the number of relapses and deaths was not significant. The outbreak may have been caused by a combination of factors: the introduction of the parasite from an endemic area to a non-immune population, the presence of malnutrition caused by loss of cattle and unavailability of other food sources, and possibly an ecological change in favour of the sandfly vector.

Adolescent↗
PubMedDate not supplied

Kala-azar: a comparative study of parasitological methods and the direct agglutination test in diagnosis.

In a comparative study 88 patients were diagnosed as suffering from kala-azar (visceral leishmaniasis) using 3 parasitological methods simultaneously. Splenomegaly was absent in 4 cases. In 84 patients with splenomegaly, splenic aspiration appeared to be the most sensitive method (96.4%), followed by bone marrow aspiration (70.2%) and lymph node aspiration (58.3%). There was no relation between titres in the direct agglutination test and parasite load as determined by the number of parasitological methods which were positive or parasite density in splenic aspirates. Splenic aspiration and bone marrow aspiration were compared as an assessment of cure in kala-azar. In 6 (13%) of 46 patients tested, parasites were found, all by splenic aspiration. Bone marrow showed parasites in one of these. The literature with regard to parasitological investigations before and after treatment is reviewed.

Agglutination Tests↗
PubMedDate not supplied

Post kala-azar dermal leishmaniasis in the Sudan: clinical features, pathology and treatment.

The clinical features, pathology, immune responses, diagnosis and treatment of post kala-azar dermal leishmaniasis (PKDL) in the Sudan are described and discussed. The disease is characterized by maculopapular or nodular lesions on the face, limbs or trunk. Lesions appear during or within months after the treatment of visceral leishmaniasis, but in 2 of 19 patients there was no previous history of kala-azar. PKDL may be confused with leprosy both clinically and pathologically. Similarities and differences between the 2 diseases are discussed. Unlike visceral leishmaniasis, the peripheral lymphoid cells of patients with PKDL respond to Leishmania antigen and some are leishmanin positive. The response to intravenous sodium stibogluconate (20 mg/kg for 30 d) was reasonably good but some patients required repeated or more prolonged treatment. Ketoconazole in a dose of 10 mg/kg daily for 4 weeks had no effect on PKDL.

Adult↗
PubMedDate not supplied

Kala-azar in western Upper Nile province in the southern Sudan and its spread to a nomadic tribe from the north.

Since the start in 1988 of the present epidemic of kala-azar (visceral leishmaniasis) in western Upper Nile state in southern Sudan, the epidemiology of the disease in all parts of the Sudan where kala-azar has been reported was reassessed by the Leishmaniasis Research Group in Khartoum. In this paper, the spread of the epidemic is described among a nomadic tribe originating from southern Kordofan state, who migrate every year with their cattle to the Bentiu area in western Upper Nile state where the epidemic is still raging. 200 cases from this tribe were seen in Khartoum; another 56 cases were found during a field trip to the area. In addition, the Bentiu area was visited, where 301 cases were under treatment and another 52 of 1120 individuals screened were confirmed parasitologically. 20 cases of post-kala-azar dermal leishmaniasis were found. Parasites isolated from the nomadic tribe were of the same zymodeme as parasites isolated previously from the Nuer in western Upper Nile. The epidemiological findings in each state are discussed in relation to the tribes that were affected and the ecology of the area.

Adolescent↗
PubMedDate not supplied

Preparation, characterization, and antitumor activity of new cisplatin analogs with homopiperazines: crystal structure of [PtII(1-methylhomopiperazine)(methylmalonato)].2H2O.

A series of new platinum(II) and (IV) complexes with homopiperazine have been synthesized and characterized by elemental analysis, infrared, and 195Pt nuclear magnetic resonance spectroscopic techniques. The complexes are of two types: [PtIILX] (where L = homopiperazine (hpip), 1-methylhomopiperazine (mhpip), or 1,4-dimethylhomopiperazine (dmhpip), and X = 1,1-cyclobutanedicarboxylato (CBDCA), or methylmalonato ligand) and [PtIV(L-)trans-(Y)2Cl2] (where Y = hydroxo, acetato, or chloro ligand). Among the complexes synthesized, the crystal structure of [PtII(mhpip)(methylmalonato)].2H2O was determined by the single crystal X-ray diffraction method. The crystallographic parameters were orthorhombic, P2(1)2(1)2(1) (no. 19), a = 7.2014(14), b = 7.3348(15), c = 26.971(5) A, and Z = 4. The structure refinements converged to R1 = 0.0641 and wR2 = 0.1847. In this complex, platinum has a slightly distorted square planar geometry with the two adjacent corners being occupied by two nitrogens of the mhpip ligand, whereas the remaining cis positions are coordinated with two oxygen atoms of the methylmalonato group. The mhpip ligand is in a boat conformation and forms five and six membered chelating rings with platinum. The intricate network of intermolecular hydrogen bonds holds the crystal lattice together. Some of these synthesized cisplatin analogs have good in vitro cytotoxic activity against the cisplatin-sensitive human ovarian A2780 (IC50 = 0.083-17.8 microM) and the isogenic cisplatin-resistant 2780CP (IC50 = 20.1-118.1 microM) cell lines.

Antineoplastic Agents↗
PubMedDate not supplied

Maleimido derivatives of diethylenetriaminepentaacetic acid and triethylenetetraaminehexaacetic acid: their synthesis and potential for specific conjugation with biomolecules.

Immunoconjugates sometimes suffer changes in immunoreactivity and tumor targeting because the chelators used interfere with antigen binding. To try to circumvent such problems, two new homobifunctional chelating agents, 2,6-bis[p-[(beta-maleimidopropionyl) amino]benzyl]diethylenetriamine- N,N,N',N",N"-pentaacetic acid (MPBz-DTPA) and 2,9-bis [p-(beta-maleimidopropionyl)amino]benzyl] triethylenetetraamine-N,N,N',N',N",N"-hexaacetic acid (MPBz-TTHA), were synthesized for chelation of 111In and 90Y metal ions. Each of the new chelators contains two maleimido functional groups substituted at the carbon backbone. In this study, the overall chemical yields for MPBz-DTPA and MPBz-TTHA were approximately 5 and 4%, respectively. The intermediate and final compounds were purified by flash chromatography and fully characterized by 1H-NMR, 13C-NMR, and mass spectroscopy. Chemical modification of the maleimido group on each of these derivatives allowed specific conjugation with a sulfhydryl group at the hinge region of an antibody molecule and conjugation with other peptides. For instance, the two Fab' fragments, through their hinge-region sulfhydryl groups, could covalently attach to a homobifunctional chelator via thioether linkage to generate a Fab'-S-chelator-S-Fab' immunoconjugate. By design, immunoconjugates containing these new chelators will contain only one chelator derivative at a known region of antibody away from the antigen binding site. Consequently, these chelators may minimize changes in the immunoreactivity and improve tumor targeting of immunoconjugates that contain them.

Chelating Agents↗
PubMedDate not supplied

Intermediate results of Buechel Pappas unconstrained uncemented total ankle replacement for osteoarthritis.

We present the functional and radiological results after implantation of thirty five uncemented Buechel Pappas total ankle replacements by an independent surgeon. All consecutive uncemented Buechel Pappas total ankle replacements were performed by the senior author (MSA) between 1990 and 2005. All ankle replacements were performed for osteoarthritis. The patients were assessed clinically and radiologically. The average follow-up period is five years. Nine female patients and 25 male patients with an average age of 69(58-84) were enrolled. One patient died before follow-up. Ninety seven percent of patients were happy with their operation and ninety seven percent thought it was successful. Sixty six percent of patients had no, or occasional pain. All patients were mobile and forty five percent of patients required no walking aids. Only three percent of patients required two walking aids. The American Orthopaedic Foot and Ankle Society Score was 73.3(54-100) at follow-up, compared to 34.6(20-56) pre-operatively (p < 0.001). One prosthesis was revised. Two fractured medial malleoli occurred and no deep infections were noted. Buechel Pappas Uncemented Total Ankle replacement, performed by an independent surgeon, can give intermediate results comparable to data published by the designer. Patient selection is paramount. Our data compares well with results from other uncemented total ankle replacements.

Aged↗
PubMedDate not supplied

Deep vein thrombosis in a jogger.

Deep vein thrombosis is rare in young and healthy athletes. A case of venous thrombosis is reported in a young, physically fit jogger.

Adult↗
PubMedDate not supplied

Simultaneous determination of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin in beef liver by LC with fluorescence detection.

Eprinomectin, moxidectin, abamectin, doramectin, and ivermectin are drugs used to control parasitic infections in both meat-producing and nonmeat-producing animals. A number of analytical methods are available to analyze these anthelmintic drugs individually. A multiresidue screening method was developed for these drugs; however, the initial attempt to derivatize eprinomectin following the method published by Merck scientists was unsuccessful because the eprinomectin derivatization reaction was temperature- and time-dependent. The optimum time and temperature for the completion of eprinomectin derivatization were 90 min and 65 degrees C, respectively, without appreciable effect on the remaining 4 drugs. Beef liver samples were fortified with 0, 25, 50, and 100 ppb mixed standards of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin. Each set of 4 levels of recoveries was repeated 10 times with all 5 compounds. The average of 10 recoveries of 5 compounds at all 4 levels of fortification was > 70%; the coefficient of variation was < 20%.

Animals↗
PubMedDate not supplied

Confirmation of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin in beef liver by liquid chromatography/positive ion atmospheric pressure chemical ionization mass spectrometry.

A liquid chromatographic (LC) multiresidue screening procedure was developed for determination of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin in beef liver at 0, 25, 50, and 100 ppb levels. A procedure using low resolution LC/atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) was developed with further purification steps added to the quantitative LC method to confirm residues. Acetonitrile extracts of liver, prior to derivatization for LC analysis, were further purified by using a C8 solid-phase extraction cartridge and an alumina-B cartridge. The purified extract was analyzed by injection into an LC/positive ion APCI MS. Identity of the compound was confirmed by comparison of its retention time and relative intensity data with those of a standard or recovery from a fortified control liver sample. Anthelmintic drugs in acetonitrile extracts of liver containing eprinomectin, moxidectin, abamectin, doramectin, and ivermectin at 25 ppb, the lowest level of fortification used in the LC determinative method, were successfully confirmed.

Animals↗
PubMedDate not supplied

Determination of N-methylcarbamate pesticides in liver by liquid chromatography.

A liquid chromatographic (LC) method using a 2-step purification technique for the simultaneous determination of 10 carbamates in bovine, swine, and duck livers has been developed. Carbamates are extracted from liver samples with methylene chloride. After evaporation, the residues from the extract are dissolved in methylene chloride-cyclohexane (1 + 1) and cleaned up by gel permeation chromatography. The eluate containing carbamate residues is evaporated to dryness, reconstituted in methylene chloride, further purified by passing it through an aminopropyl Bond Elut extraction cartridge, and analyzed by liquid chromatography using post-column derivatization with orthophthalaldehyde and fluorescence detection. Excitation and emission are set at 340 and 418 nm, respectively. Liver samples for beef, pork, and duck were fortified with 5, 10, and 20 ppb of mixed carbamate standards. The average of 10 recoveries of 10 carbamates at all 3 levels of fortification was greater than 80% with coefficients of variation less than 17%.

Animals↗
PubMedDate not supplied

Simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products by liquid chromatography.

A liquid chromatographic (LC) method for the simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products has been developed. Dextrose, sucrose, maltose, and lactose are extracted from comminuted meat products with 52% ethanol. After filtration, the extracts are purified by passing them through a C18 Sep-Pak cartridge and 2 ion exchange resin Econo-columns in series. After concentration and filtration, extracts are analyzed by LC using a normal phase amino column and a differential refractometer detector. Homogeneously ground samples of cooked and fresh sausages are fortified with dextrose, sucrose, maltose, and lactose at 4 different concentrations. Average recovery for dextrose, sucrose, maltose, and lactose at all 4 levels of fortification was greater than 80% with a coefficient of variation less than 10%.

Carbohydrates↗
PubMedDate not supplied

Rapid quantitative method for simultaneous determination of benzoic acid, sorbic acid, and four parabens in meat and nonmeat products by liquid chromatography.

A liquid chromatographic (LC) method for the simultaneous determinations of benzoic acid, sorbic acid, and methyl, ethyl, propyl, and butyl parabens (methyl, ethyl, propyl, and butyl-p-hydroxybenzoates) in meat and nonmeat products was developed. Benzoic acid, sorbic acid, and parabens were extracted from meat and nonmeat products with 70% ethanol. After filtration, extracts were analyzed by reverse phase liquid chromatography. Homogeneously ground samples of fresh sausage and hamburger were fortified with benzoic acid, sorbic acid, and each paraben at 5 different concentrations. Average recovery (after discarding outliers) for each preservative at all 5 levels was greater than 95% with a coefficient of variation less than 5%.

Animals↗
PubMedDate not supplied

Gas chromatographic/mass spectrometric confirmation of ten N-methylcarbamate insecticides in liver.

A gas chromatographic/mass spectrometric (GC/MS) confirmation procedure for 10 phenyl-N-methyl-carbamate insecticides in liver tissue was developed. The extract from liquid chromatography (LC) is purified with a C18 solid-phase extraction cartridge and then derivatized with heptafluorobutyric anhydride; the derivative is injected for analysis by GC/MS with electron ionization and multiple ion monitoring. The identity of the derivative is confirmed by comparison of its retention time and relative intensity data with those of a standard. Liver extracts from the LC procedure containing carbamates at 10 ppb levels were successfully confirmed by this procedure.

Animals↗
PubMedDate not supplied

Analyte stability study of N-methylcarbamate pesticides in beef and poultry liver tissues by liquid chromatography.

To optimize conditions for sample collection, preparation, storage, and analysis and to assure the validity of our previously published liquid chromatographic (LC) method for carbamate analysis in tissue, stabilities of 16 N-methylcarbamates in beef, duck, and chicken liver tissues were studied by using 2 sampling protocols. Tissue samples were fortified at room temperature to a concentration 5 to 10 times greater than either the Environmental Protection Agency tolerance level for each compound (if established) or the concentration used in the previously published method. Thereafter, samples were continuously frozen at -4 degrees C for varying time intervals. In the first study, samples were analyzed one day (initial) and 0.5, 1, 1.5, 2, 3, 4, 5, and 6 months after fortification. In the second study, samples were analyzed one day (initial) and 0.5, 1, 2, 3, and 6 months after fortification. For each residue and species, a minimum of 4 samples were analyzed by LC at each point in time, and the mean represented analyte concentration at the end of each time interval. Rates of residue depletion varied among analytes and among species. Depletion rates were greater in duck livers than in beef livers. Methomyl and oxamyl were depleted completely within 2 weeks. Between 2 and 6 months after sample fortification, residue depletions to levels below detection limits were observed for aldicarb, aldicarb sulfoxide, aldicarb sulfone, dioxacarb, promecarb, propoxur, and bendiocarb. The initial loss of certain carbamates during sample preparation in tissues exposed to room temperature for up to 8 h was greater than the subsequent rate of loss. Results indicate that cryogenic conditions are required for sample preparation and storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗