A light-scattering spectrometer for medical diagnostic tasks

Whether a high-resolving light scattering spectrometer may be used in medical practice is discussed in the paper. The results of the experiments on blood components and microorganisms are discussed.     

'Tunable' positive and negative surface charges on a capillary wall: exploiting the Immobiline chemistry

The Immobiline (weak acrylamido acids and bases) chemistry has been applied to the covalent attachment of a positively (or, if needed, negatively) charged layer onto the inner surface of the silica wall. In particular, the following basic Immobilines have been used: pK 6.2, pK 7.0, pK 8.5 and pK 9.3. In order to avoid pK changes, the charged Immobilines are mixed with neutral acrylamido derivatives (in particular the highly resistant and hydrophilic N-acryloyl aminoethoxyethanol) so as to form a co-polymer having a 1:5 molar ratio (charged to neutral). The mu(eo) vs. pH curves have a slope opposite to that of a naked capillary and fan out on the pH scale following the titration curves of the different weak bases. Such chemistry allows the covalent attachment of charged species having known pK values and offering controlled charged densities on the wall. However, with the atomic force microscope, it is found that such soft coatings (whether charged or neutral) do not seem to provide complete coverage of the surface: naked patches of fused silica are found interdispersed among the polymer-coated ones. A good solution is a hybrid bonded and dynamic coating, obtained by adding short chain linear polyacrylamides to the background electrolyte. Good separations of polycations [poly(L-histidine)] and of histones are reported up to pH 5.7.     

Subchronic oral hepatotoxicity of turmeric in mice--histopathological and ultrastructural studies

OBJECTIVE: To analyze the effects of flutamide in patients with physical and/or mental disorders consulting for urinary symptoms secondary to benign prostatic hyperplasia (BPH). METHODS: 50 patients with BPH in whom surgical treatment was contraindicated due to their physical and/or mental condition were treated with flutamide 250 mg/day. Four patients presented with urinary retention and 46 patients had prostatic symptomatology. Patients were evaluated using the symptoms score (I-PSS) and quality of life (QL). Prostate volume was measured by transabdominal US; the maximum flow rate at spontaneous micturition and residual urine were determined. RESULTS: At 12 months, the I-PSS and QL scores decreased by a mean of 7 and 3 points, respectively. The US demonstrated that treatment had reduced prostatic volume by a mean of 10 gms. The maximum flow rate at spontaneous micturition increased 3 ml/sec and residual urine decreased by 15 ml. CONCLUSION: Flutamide is another alternative to surgery in specific patients with BPH.     

An oxazine reagent for derivatization of carboxylic acid analytes suitable for liquid chromatographic detection using visible diode laser-induced fluorescence

This study reports the use of Nile Blue, an oxazine dye, as a derivatization reagent that fluoresces in the far-red spectral region and is suitable for derivatization with carboxylic-acid-containing analytes. Model carboxylic acid analytes such as benzoic acid, acetic acid, phenylacetic acid and hexanoic acid have been reacted as acid chlorides to form Nile Blue derivatives. The synthesis product of the Nile Blue benzoic acid derivative was confirmed using electrospray-mass spectrometry, infrared spectrometry, 1H and 13C nuclear magnetic resonance, reversed phase liquid chromatography (RP-HPLC), normal phase-thin layer chromatography, and spectral characterization. The synthesized Nile Blue derivatives, separated from reaction by-products with RP-HPLC, all demonstrated an approximately 10-fold drop in molar absorptivity and relative quantum yield. In addition, a 40 nm increase in Stokes shift was observed. A portion of the fluorescence was regained through post-column ionization of the Nile Blue benzoic acid derivative at pH 12. A RP-HPLC limit of detection of 88.25 fmol on column has been reported with conventional fluorescence detection-post-column ionization of the Nile Blue benzoic acid derivative. A limit of detection of 1.99 fmol on column (3.98 x 10(-11) M) has been demonstrated for the Nile Blue benzoic acid derivative with the use of a laboratory-constructed visible diode laser fluorescence detector.     

Stress increases the population of splenic macrophages, permissive for Langat virus, in mice

Cytogenetic study conducted after a single intraperitoneal injection of cyclophosphane in doses of 10, 20, and 40 mg/kg showed in 1.5-2-month-old male mice that the level of bone marrow cells damaged by the mutagen was significantly higher in NZW animals than in C57Bl/6 animals. The ability to produce active oxygen forms in response to addition of opsonized zymosan and phorbol myristate acetate was also higher in bone marrow suspensions of NZW mice. The higher sensitivity of NZW animals to pro-oxidant and clastogenic effects may be related to the genetically determined decrease of antioxidant protection in NZW animals.     

Conduct disorder with and without mania in a referred sample of ADHD children

OBJECTIVE: To test the hypothesis that dysphoric and non-dysphoric types of CD could be distinguished from one another in their patterns of familiality, adversity, and comorbidity. METHODS: We examined 140 ADHD and 120 normal controls at baseline and 4 years later using assessments from multiple domains. We compared ADHD subgroups with and without conduct (CD) and bipolar (BPD) disorders on psychiatric outcomes at a 4-year follow-up, familial psychopathology and psychosocial functioning. RESULTS: We found that ADHD children with both disorders had higher familial and personal risk for mood disorders than those with CD only, who had a higher personal risk for antisocial personality disorder. Among ADHD probands, having both CD and BPD was associated with poorer functioning and an increased risk for psychiatric hospitalization. DISCUSSION: Although preliminary, our findings suggest that the distinction between dysphoric and non-dysphoric CD may be clinically meaningful. If confirmed, our findings could have important diagnostic and therapeutic implications for the management of antisocial youth.     

Distinct roles of the interleukin-7 receptor alpha chain in fetal and adult thymocyte development revealed by analysis of interleukin-7 receptor alpha-deficient mice

Mouse mutants lacking expression of the IL-7 receptor (IL-7R) alpha chain are defective in thymopoiesis. The adult thymus has multiple defects, including reduced cell numbers and proportions of the more mature thymocyte subsets, a complete absence of CD25+ cells and a reduced level of RAG1 and RAG2 expression. We show here that, in contrast to the profound developmental arrest observed in the adult thymus, fetal thymocytes from IL-7Ralpha-/- mice have normal proportions of all of the major thymocyte subpopulations, including CD25+ thymocytes and the most mature single-positive subsets. Moreover, normal levels of RAG1 and RAG2 were observed. Total thymocyte numbers, however, remained reduced. These data suggest that the IL-7Ralpha chain is a key regulator of both survival and proliferation during thymocyte development but that it is not essential for the production of T cells during fetal thymopoiesis.     

Functional stereotaxy with magnetic resonance tomographic guidance

The paper summarizes experience with stereotactic operations by magnetic resonance imaging data by using a Russian OREOL stereotactic manipulator. It describes methods of preoperative preparation of patients by employing diagnostic magnetic resonance tomographs. A number of points of the procedure for identification and localization of deep target structures from magnetic resonance images in parkinsonism, temporal epilepsy and some mental disorders.     

Mechanism of action of human P-glycoprotein ATPase activity. Photochemical cleavage during a catalytic transition state using orthovanadate reveals cross-talk between the two ATP sites

Human P-glycoprotein (P-gp), an ATP-dependent efflux pump responsible for cross-resistance of human cancers to a variety of lipophilic compounds, is composed of two homologous halves, each containing six transmembrane domains and an ATP-binding/utilization domain. To determine whether each site can hydrolyze ATP simultaneously, we used an orthovanadate (Vi)-induced ADP-trapping technique (P-gp.MgADP.Vi). In analogy with other ATPases, a photochemical peptide bond cleavage reaction occurs within the Walker A nucleotide binding domain consensus sequence (GX4GK(T/S)) when the molecule is trapped with Vi in an inhibited catalytic transition state (P-gp.MgADP.Vi) and incubated in the presence of ultraviolet light. Upon reconstitution into proteoliposomes, histidine-tagged purified P-gp from baculovirus-infected insect cells had drug-stimulated ATPase activity. Reconstituted P-gp was incubated with either ATP or 8-azido-ATP in the presence or absence of Vi under ultraviolet (365 nm) light on ice for 60 min. The resultant products were separated by SDS-polyacrylamide gel electrophoresis and subjected to immunoblotting with seven different human P-gp-specific antibodies covering the entire length of the molecule. Little to no degradation of P-gp was observed in the absence of Vi. In the presence of Vi, products of approximately 28, 47, 94, and 110 kDa were obtained, consistent with predicted molecular weights from cleavage at either of the ATP sites but not both sites. An additional Vi-dependent cleavage site was detected at or near the trypsin site in the linker region of P-gp. These results suggest that both the amino- and carboxyl-terminal ATP sites can hydrolyze ATP. However, there is no evidence that ATP can be hydrolyzed simultaneously by both sites.