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Biomedical subjects

M Sarwar

Publications and source records attributed to M Sarwar.

At least 19 recordsLinked to original sources
PubMed1992

Effects of varying forage and concentrate carbohydrates on nutrient digestibilities and milk production by dairy cows.

Five Holstein cows with ruminal cannulas were used in a 5 x 5 Latin square design to determine the effect of replacing forage NDF with soyhull NDF and varying concentrations of nonstructural carbohydrates on nutrient digestion and milk production. Diets in which NDF percentage from forage (corn silage: alfalfa hay, 1:1) was 80 (control), 70, or 60 were formulated by substituting soyhulls for forage; total forage was 43.2, 36.7, and 31.1% of the diets, respectively, but total NDF was 31%. Nonstructural carbohydrates were formulated to be 47 (control), 35, or 25% by substituting soyhulls, roasted soybeans, and Ca soaps for concentrate. Ruminal acetate: propionate ratio decreased linearly when diets lower in forage NDF were fed, but it increased quadratically when dietary nonstructural carbohydrates were reduced. Apparent digestibility of OM increased quadratically, but NDF digestibility and lactation performance were unaffected when diets lower in forage NDF were fed. Digestibility of NDF increased linearly when nonstructural carbohydrates were reduced, perhaps because of greater digestibility of soyhull NDF and smaller negative associative effects. Fat from soybeans and Ca soaps was increased as nonstructural carbohydrates decreased. Added fat probably increased fatty acid digestibility and decreased milk protein percentage. Greater FCM production without correspondingly greater feed intake or BW loss increased feed efficiency as nonstructural carbohydrates decreased. In dairy rations containing soyhulls, 60% of dietary NDF from forage should maintain lactation performance, and decreasing nonstructural carbohydrates to 25 to 35% of feed DM, coupled with adding dietary fat, may decrease negative associative effects and improve efficiency of milk production.

Ammonia↗
PubMed1990

Cloning of aminoglycoside phosphotransferase (APH) gene from antibiotic-producing strain of Bacillus circulans into a high-expression vector, pKK223-3. Purification, properties and location of the enzyme.

The aminoglycoside phosphotransferase gene from a butirosin-producing strain of Bacillus circulans was cloned in a high-expression vector (pKK223-3) to give the recombinant plasmid pMS5. Escherichia coli harbouring the plasmid, E. coli JM103[pMS5], was characterized, and several features of the expression of the phosphotransferase were studied. The phosphotransferase activity was best expressed in a medium lacking glucose, and the highest levels of the enzyme were found between 12 and 24 h of growth. The induction of the phosphotransferase expression with isopropyl beta-D-thiogalactopyranoside (inducer) was found to be undesirable as the overproduction of the enzyme led to the killing of the bacteria. The subcellular location of the phosphotransferase, and also the site in vivo of the phosphorylation of neomycin, was found to be in the cytoplasm. The phosphotransferase was purified to homogeneity in good yield (17 mg of purified protein/3 litres of culture) and was shown to be a monomer of Mr 30,000-32,000. The N-terminal amino acid sequence was in agreement with that predicted from the gene sequence and confirmed the absence of any signal sequence. The regiospecificity of the phosphotransferase reaction was studied by m.s. and by 1H-, 13C- and 31P-n.m.r. using ribostamycin as the substrate, and it was found that the antibiotic was phosphorylated at the 3'-hydroxy group.

Amino Acid Sequence↗
PubMed1990

Imaging of the pediatric spine and its contents.

We are at the crossroads of imaging of the diseases of the spine and its contents. There are different competing imaging modalities, each with its own merits and demerits. This review paper is designed to identify the strengths and weaknesses of the various available imaging modalities and to recommend one or a combination of imaging modalities that are suited for assessing a particular disease process. At present, magnetic resonance imaging has proved its extreme usefulness in depicting diseases of the spinal cord and its coverings. As more innovations and sophistications occur in magnetic resonance imaging, it is hoped that it will play a pivotal role in the investigation of abnormalities of the spinal cord and perhaps even of the spine itself.

Adolescent↗
PubMed1986

Sequence and interspecies transfer of an aminoglycoside phosphotransferase gene (APH) of Bacillus circulans. Self-defence mechanism in antibiotic-producing organisms.

The APH gene of a butirosin-producing Bacillus circulans was cloned and shown to be expressed in Escherichia coli and Streptomyces lividans. The gene was sequenced and a possible developmentally regulated promoter identified. When the deduced protein sequence was compared with those from transposon Tn5, transposon Tn903, Streptomyces fradiae, Staphylococcus aureus and Streptococcus faecalis, significant homology was found, indicating that the genes may have a common origin.

Bacillus↗
PubMed1986

Radiologic techniques in the diagnosis of CNS infections.

The radiologic diagnosis of CNS infections remains a challenge. CT scan findings, though admittedly nonspecific to a large extent, assume great diagnostic significance when considered in conjunction with clinical and laboratory findings. MRI is expected to show abnormalities in the earlier stages of these infections.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Genetic brain malformations recapitulate phylogeny.

It is generally difficult to establish whether a congenital brain malformation has a genetic basis or is due to other factors. A thesis has been developed, that brain malformations with a genetic basis recapitulate phylogeny. In order to validate this thesis a retrospective CT investigation of brain dysmorphology was carried out in 50 cases of dysgenesis of the corpus callosum, 20 cases of the holoprosencephaly complex, 25 cases of Dandy-Walker malformation, and 50 cases of miscellaneous brain anomalies. This group was compared with 100 neonates with brain damage from acquired causes. The results strongly suggest that a brain malformation that recapitulates phylogeny is very likely to be based on genetic aberration.

Animals↗
PubMed1985

Chloroquine-resistant Plasmodium falciparum: now in Pakistani Punjab.

To investigate the susceptibility of Plasmodium falciparum to chloroquine in Pakistani Punjab, in-vivo and in-vitro drug susceptibility was tested in 3 villages. Of 66 patients followed for up to 14 days after chloroquine treatment, 53 (80%) had parasites sensitive to chloroquine, 10 (15%) had parasites with early RI resistance, and 3 (5%) had parasites with RII resistance. Of 42 falciparum isolates investigated in vitro, 12 were sensitive, 8 intermediate, and 22 resistant to chloroquine. The degree of in-vivo resistance correlated with the degree of in-vitro resistance. It is concluded that chloroquine resistance is common among falciparum parasites in Pakistan and that this chloroquine resistance could explain the recent increase in the prevalence of falciparum malaria in the Punjab. Alternative antimalarials should therefore be investigated for both treatment and chemoprophylaxis against falciparum parasites in Pakistan.

Chloroquine↗
PubMed1979

The Dens-Arch synchondrosis versus the Hangman's fracture.

The synchondrosis between the dens and arch of C2 is a normal structure in infants and children. It is not visible on lateral views of the cervical spine, but is routinely visible on oblique views. In such cases it has a distinct tendency to mimic a C2-arch fracture. The varying appearance of this synchondrosis and its differentiation from a true fracture of C2 are the subjects of this report.

Arthrography↗
PubMed1979

The posteriorly tilted dens. A normal variation mimicking a fractured dens.

The normal dens occasionally can be posteriorly tilted and in such cases, can mimic a fractured, posteriorly tilted, dens. Differentiation of the two conditions depends on: [1] knowledge that this normal variation of the dens occurs, and [2] demonstrating that no fracture exists. In many cases, this latter determination can be accomplished on plain films, but in other cases, laminography is required.

Axis, Cervical Vertebra↗
PubMed1978

Intracerebral venous angioma. Case report and review.

Only a few cases of angiographically demonstrated and pathologically proved cases of venous angiomas have been published. In contrast to the scarcity of recorded cases of angiographically studied venous angiomas, they are the most common incidentally encountered angiomatous lesions at autopsy. Their angiographic characterization, though highly suggestive, is not pathognomonic. The angiographic characteristics include small radiating veins that drain into a larger transcerebral vein that in turn empties into a dural sinus; blush and early draining veins also may be seen. The differential diagnosis includes telangiectasia, infiltrating glioma, and probably a cavernous angioma. We report an angiographically demonstrated and pathologically proved case of a venous angioma and also review the literature.

Adult↗