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Biomedical subjects

A Mohammed

Publications and source records attributed to A Mohammed.

At least 73 records · Page 4Linked to original sources
PubMed1983

Studies on the tissue disposition and fate of [14C]toxaphene in Japanese quail.

The disposition and the fate of a [14C]toxaphene preparation was studied in adult and juvenile female Japanese quail. The distribution of [14C]toxaphene in the body is dominated by high concentrations of radioactivity in the adipose tissue and the egg yolk, and, especially in juvenile birds, in the bone marrow. The [14C]toxaphene compounds present in the fat tend to be less polar than the parent [14C]toxaphene. More than half of the radioactive dose is excreted via the droppings, eggs, and preen gland within a few days, with biliary excretion playing a major role. The main part of the radioactivity in feces and urine consists of water soluble compounds, a part of which is indicated to be glucuronide and sulfate conjugates, but other metabolites are probably also present. A possible connection between the toxaphene residues in the bone and the known toxaphene induced osteomalacia in birds is discussed.

Adipose Tissue↗
PubMed1982

Enzyme immunoassay of gentamicin with the Abbott ABA-100 analyzer.

The enzyme immunoassay of gentamicin using "EMIT" reagents was adapted to take advantage of the small reagent volume required by the Abbott ABA-100. The method increases fourfold the maximum number of tests per kit. The correlation with the bacterial inhibition method was 98%.

Autoanalysis↗
PubMed1981

Management of early glottic cancer.

A detailed retrospective analysis of 136 patients with early glottic cancer treated at the University of Louisville, Radiation Center from October, 1953 to December, 1975 was done. Majority of the patients were in the age range of 55 to 74 years. Of them, 89% were male and 85% were Caucasian. The most common histological type was squamous cell carcinoma. The adjusted 5-year survival rate was 84%, with a standard error of 3%. Of these patients, 18% had local failures, and 68% of which were salvaged by surgery. The overall local control rate was 93%. The median time to recurrence was 23 months. There was no case of laryngeal necrosis, and a good function of larynx was achieved in a majority of the patients. Eighteen second cancers were diagnosed in 17 patients during the follow-up. A brief review of the literature is also done in the paper.

Adult↗
PubMed1981

Persistence of 2,3,6-substituted pentachlorobiphenyls in the lung parenchyma: a new structure-dependent tissue localization of polychlorinated biphenyls in mice.

Whole body autoradiograms of mice injected with 2,2',3,3',6-[14C]pentachlorobiphenyl (I), 2,3,3',4',6-[14C]pentachlorobiphenyl (II), 2,2',3,5',6-[14C]pentachlorobiphenyl (III) and 2,3',4,5,5'-[14C]pentachlorobiphenyl (IV) showed a specific accumulation of I-III in the lung parenchyma, whereas IV did not accumulate in the lung tissue. The results suggest that chlorobiphenyls with chlorine atoms in the positions 2,3,6 possess a specific affinity for the lung parenchyma. These chlorobiphenyls differ in chemical structure from those which are accumulated in the bronchial mucosa and those which are not taken up in the respiratory tract. The importance of in vivo metabolism in the determination of structure activity relationships is stressed.

Animals↗
PubMed1980

Automated determination of urine and cerebrospinal fluid proteins with Coomassie Brilliant Blue and the Abbott ABA-100.

We have evaluated the use of Coomassie Brilliant Blue (CBB) dye to measure the protein of urine and cerebral spinal fluid. The method was automated and compared with the turbidimetric method and with Ponceau S dye. With both the manual and automated procedures the CBB method could be used to protein concentrations of 160 mg/dl. Comparing this method to the method measuring the turbidity produced by trichloracetic acid (TCA) we found a correlation coefficient (r) of 0.96. The regression line was CBB = 0.84 TCA + 4.97. A similar comparison to the method using Ponceau S (PS) produced an r = 0.98 and the regression line, CBB = 0.91 P-S + 3.2. The CBB method was not as affected by turbidity in the samples or by xanthochromia as was the TCA Method. It is simpler to perform than the P-S method, since it does not require decantation. With the manual method, the coefficient of variation (CV) at 40 mg/dl for within-day determinations was less than 2% and, for between-day determinations, less than 4%. While the CV was somewhat higher with the ABA than with the manual method at 40 mg/dl, it was below 5% for both within-day and between-day determinations at the concentrations between 70 and 170 mg/dl. The method using CBB is useful as both a manual and automated procedure to measure protein in urine and cerebral spinal fluid.

Autoanalysis↗
PubMed1980

Radiation therapy of glottic carcinoma stage I.

A detailed retrospective analysis of 81 patients with a diagnosis of glottic carcinoma stage I (T1N0M0) from 1953 to 1975 has been done. Eighty-eight per cent of the patients were male and 80 per cent of the total number were white. The majority of the patients received a dose of 64 Gy in 6 1/2 weeks. The crude 5-year actuarial survival rate was 69 per cent and the adjusted 5-year actuarial survival rate was 86 per cent. Local recurrence occurred in 12 per cent and of these 80 per cent were cured by surgery. The median time of recurrence was 25.5 months. No case of laryngeal necrosis occurred, and 10 second malignant tumors were diagnosed in the follow-up.

Aged↗
PubMed1979

Enzyme immunoassay of theophylline with the Abbott ABA-100.

The enzyme immunoassay of theophylline using the "EMIT" reagents was adapted to the Abbott ABA. The method greatly increases the maximum tests per kit. The correlation with high pressure liquid chromatography was 99%. No interference with bilirubin was found at 15 mg/dl. of total bilirubin. The method is useful for pediatric patients including newborns.

Autoanalysis↗
PubMed1979

Use of Beckman BUN analysers to determine urine urea.

In this paper we report a method to enable the Beckman BUN analyser to be used for urine urea nitrogen determinations. Satisfactory urine samples could be obtained by diluting the urine with 10 volumes of 0.85% saline. We also report our experience with the use of reagent prepared in house and with a modified pipette, to reduce the cost of using the instrument.

Autoanalysis↗
PubMedDate not supplied

Toxaphene: accumulation in the adrenal cortex and effect on ACTH-stimulated corticosteroid synthesis in the rat.

Uptake and distribution of [14C]toxaphene was studied in the adrenals of rats using whole-body autoradiography. An accumulation of radioactivity was seen in the adrenal cortex (zona fasciculata) 1-24 h after a single gavage of [14C]toxaphene (16 mg/kg b.w.). In in vitro studies toxaphene was found to inhibit ACTH-stimulated corticosterone synthesis in the cultured rat adrenocortical cells (IC50 2.8 X 10(-5) M). Moderate but significant inhibition (P less than 0.001) of ACTH-stimulated corticosterone synthesis was also observed in the adrenocortical cells isolated from rats after a prolonged exposure (5 weeks) to low levels (1.2 ppm) of toxaphene in feed. The results indicate a direct adrenotoxic effect of toxaphene.

Adrenal Cortex↗
PubMedDate not supplied

Preparation and evaluation of tumor-targeting peptide-oligonucleotide conjugates.

Enormous progress has been made in the development of antisense oligodeoxynucleotides (ODNs) as therapeutic agents inhibiting gene expression. Unfortunately, the therapeutical application of ODNs is still held back because of the low cellular uptake and the lack of specific transport into particular cells. In this paper, we report a drug-targeting system using somatostatin receptors (SSTRs) which are overexpressed in various tumors. Phosphorothioate ODNs were covalently linked to Tyr(3)-octreotate, an analogue of somatostatin. The peptide was assembled by solid-phase synthesis, oxidized to form the cyclic disulfide, and subsequently derivatized with a N-terminal maleimido functionality. 5'-Thiol derivatized phosphorothioate-ODNs directed against the protooncogene bcl-2 were conjugated to this maleimido-modified peptide. Binding studies revealed that the conjugates retain specific binding with nanomolar affinities to SSTRs (IC(50)-values between 1.83 and 2.52 nM). Furthermore, melting studies with complementary DNA revealed that the terminal conjugation of the ODNs did not significantly affect their hybridization affinity.

Base Sequence↗
PubMedDate not supplied

2,3,5,6-Tetrafluorophenyl N-(S-benzoylthioacetyl)glycylglycyl- p-aminobenzoate, a heterobifunctional (99m)Tc ligand for precomplexed antibody labeling.

Heterobifunctional (99m)Tc ligands are useful for antibody labeling using the precomplexation route. The aim of this work was to synthesize a ligand, which has sufficient chemical stability to be complexed with (99m)Tc without inactivating the reactive conjugation group. Using 2,3,5,6-tetrafluorophenyl N-(S-benzoylthioacetyl)glycylglycyl-p-aminobenzoate (OC2) >60% of the (99m)Tc complex was obtained at 80 degrees C in 20 min, which was separated from the free ligand and impurities by HPLC. After solvent evaporation, (99m)Tc-OC2 was conjugated with the monoclonal antibody mAb425 in 50% radiochemical yield. In all, the labeling method required about 1 h preparation time. The immunoreactive fraction of the (99m)Tc-OC2 mAb425 conjugate was 81%, indicating preserved binding capability after conjugation. Compared to recently described methods, which need in situ activation of the (99m)Tc complex, the application of OC2 saved time and reduced the number of manipulations with radioactive material.

4-Aminobenzoic Acid↗