A rapid morphometric method for determining thyroid gland function

The incidence of postoperative hypothyrosis after subtotal resection of the thyroid for diffuse toxic goiter is rather high, 40-50% according to many authors. A method is suggested permitting assessment of the share of "active zones" during surgery. A certain amount of thyroid tissue is left with due consideration for this share, this amount being sufficient to attain an euthyroid state in the postoperative period.     

Tuberculosis screening: usefulness of new KREATECH IgA ELISA test

A total of 71 sera from 15 proved cases of pulmonary tuberculosis, 2 cases with doubtful radiological report and 54 suspected cases, contacts, donors etc. were subjected to Elisa IgG, IgM and IgA tests for tuberculosis, with a view to comparing the merits of IgA test with those of IgG and IgM. Kreatech IgA test which is claimed to indicate presence of active tuberculosis was positive in 13 of the proved cases and negative in both the doubtful cases. These preliminary results indicate that KREATECH IgA is a promising new ELISA test which can be a useful laboratory aid in the diagnosis of active tuberculosis, both pulmonary and extrapulmonary, for screening of suspected cases, and for monitoring cases undergoing therapy.     

Some biochemical properties of Acholeplasma laidlawii mutants defective in glucose carrier

Some membrane properties of glucose transport system of Acholeplasma laidlawii mutants uncapable of uptaking glucose as well as those of its non-metabolizing analogue, 3-0-methylglucose are studied. In contrast to the wild strain the mutant PTL-S cells fail to uptake carbohydrates with the saturation. There is no competition between carbohydrates during transport in this mutant no sugar exit is observed, and the sensitivity of transport to thiol reagents and pronase B is considerably affected. All other investigated membrane functions were intact. The data given indicate the presence of a specific defect in glucose transport system.     

Character of structural disturbances caused by chloroalkylamines in the model and erythrocyte membranes

beta, beta-Dichlorodiethylamine is proved not to induce structural disturbances in phosphatidylcholine liposomes and erythrocyte membranes which is registered by fluorescence methods. Methyl-beta, beta-dichlorodiethylamine and metaxylyl-beta, beta-dichlorodiethylamine cause the increase in microviscosity of lipid bilayer hydrophobic areas in both erythrocyte membranes and liposomes. Besides, polarity of the latter also decreases, and the metaxylyl derivative alkylates nucleophilic centers of phospholipid phosphate groups in liposomes. Erythrocyte membranes, being treated by beta, beta-dichlorodiethylamine derivatives, the increase in the membrane protein hydrophobicity is registered as well as the decrease in their immersion in the lipid bilayer.     

The distribution of direct interactions in the spatial structures of globular proteins

The hydrogen bond distributions in 123 protein structures with the atom coordinates established at a resolution of less than 2 A were analyzed. The peculiarities of hydrogen bond distributions with respect to the lengths and remoteness of contacting residues in the primary structure were established. A hierarchy of H-bond energy distribution in the spatial structure of protein globules was demonstrated. The role of hydrogen bonds in the formation of domain structure and their special properties in proteins with different types of secondary structure are discussed.     

Validation of a model predicting enrollment status in a chemoprevention trial for breast cancer

A simple, rapid, and sensitive method which allows us to simultaneously determine bromvalerylurea (BVU) and its three metabolites (3-methylbutyrylurea [MVU], alpha-(cystein-S-yl)isovalerylurea [CVU], and alpha-(N-acetylcystein-S-yl)isovalerylurea [AcCVU]) was investigated by frit-fast atom bombardment liquid chromatography-mass spectrometry (frit-FAB LC-MS). The LC-MS analysis was performed after the solid-phase extraction from tissue and urine samples with a Sep-Pak C18 cartridge. Tissue homogenates and urine were adjusted to pH 4.0 and applied to the cartridges. The retained BVU and its metabolites were eluted from the cartridge with 2 mL of acetonitrile/10 mM ammonium acetate buffer (pH 3.5, 50:50, v/v). The eluate was analyzed by LC-MS, which employs a semimicro type L-column ODS column. The proposed conditions are as follows: mobile phase A, 0.4% glycerol in acetonitrile/10 mM ammonium acetate buffer (pH 3.5) (5:95, v/v); mobile phase B, 0.4% glycerol in acetonitrile; elution mode, linear gradient, 100% A (5 min) to 100% B in 15 min; flow rate, 0.2 mL/min; split ratio, 1:40. Extraction recoveries of BVU and its metabolites were 91.90-97.79% from the spiked liver homogenate and 89.68-96.13% from the spiked urine. The detection limits ranged from 10 to 25 ng/g in selected ion monitoring mode.     

In vitro resistance to thrombin-induced platelet microbicidal protein among clinical bacteremic isolates of Staphylococcus aureus correlates with an endovascular infectious source

Platelet microbicidal proteins (PMPs), small cationic peptides released at sites of endovascular damage, kill common bloodstream pathogens in vitro. Our group previously showed that in vitro resistance of clinical staphylococcal and viridans group streptococcal bacteremic strains to PMPs correlated with the diagnosis of infective endocarditis (IE) (Wu et al., Antimicrob. Agents Chemother. 38:729-732, 1994). However, that study was limited by (i) the small number of Staphylococcus aureus isolates from IE patients, (ii) the retrospective nature of the case definitions, and (iii) the diverse geographic sources of strains. The present study evaluated the in vitro PMP susceptibility phenotype of a large number of staphylococcemic isolates (n = 60), collected at a single medical center and categorized by defined and validated clinical criteria. A significantly higher proportion of staphylococcemic strains from patients with IE was PMP resistant in vitro than the proportion of strains from patients with soft tissue sepsis (83% and 33%, respectively; P < 0.01). Moreover, the levels of PMP resistance (mean percent survival of strains after 2-h exposure to PMP in vitro) were significantly higher for isolates from patients with IE and with vascular catheter sepsis than for strains from patients with abscess sepsis (P < 0.005 and P < 0.01, respectively). These data further support the concept that bloodstream pathogens that exhibit innate or acquired PMP resistance have a survival advantage with respect to either the induction or progression of endovascular infections.