A quantum chemical based toxicity study of estimated reduction potential and hydrophobicity in series of nitroaromatic compounds.

Nitroaromatic compounds and the products of their degradation are toxic to bacteria, cells and animals. Various studies have been carried out to better understand the mechanism of toxicity of aromatic nitrocompounds and their relationship to humans and the environment. Recent data relate cytotoxicity of nitroaromatic compounds to their single- or two-electron enzymatic reduction. However, mechanisms of animal toxicity could be more complex. This work investigates the estimated reduction and oxidation potentials of 34 nitroaromatic compounds using quantum chemical approaches. All geometries were optimized with density functional theory (DFT) using the solvation model based on density (SMD) and polarizable continuum model (PCM) solvent model protocols. Quantitative structure-activity/property (QSAR/QSPR) models were developed using descriptors obtained from quantum chemical optimizations as well as the DRAGON software program. The QSAR/QSPR equations developed consist of two to four descriptors. Correlations have been identified between electron affinity (ELUMO) and hydrophobicity (log P).

AMPA glutamate receptor subunits 1 and 2 regulate dendrite complexity and spine motility in neurons of the developing neocortex.

Within neurons of several regions of the CNS, mature dendrite architecture is attained via extensive reorganization of arbor during the developmental period. Since dendrite morphology determines the firing patterns of the neuron, morphological refinement of dendritic arbor may have important implications for mature network activity. In the neocortex, a region of brain that is sensitive to activity-dependent structural rearrangement of dendritic arbor, the proportion of AMPA receptors increases over the developmental period. However, it is unclear whether changes in AMPA receptor expression contribute to maturation of dendritic architecture. To determine the effects of increasing AMPA receptor expression on dendrite morphology and connectivity within the neocortex, and to determine whether these effects are dependent on specific AMPA receptor subunits, we overexpressed the AMPA glutamate receptor subunit 1 (GluR1) and glutamate receptor subunit 2 (GluR2) in cultured rat neocortical neurons at the time that AMPA receptors would normally be incorporated into synapses. Following expression of GluR1 or GluR2 we observed increases in the length and complexity of dendritic arbor of cortical neurons, and a concurrent reduction in motility of spines. In addition, expression of either subunit was associated with an increased density of excitatory postsynaptic puncta. These results suggest that AMPA receptor expression is an important determinant of dendrite morphology and connectivity in neocortical neurons, and further, that contrary to other regions of the CNS, the effects of AMPA receptors on dendrite morphology are not subunit-specific.

Outcome of consecutive pregnancies in a patient with Bombay (Oh) blood group.

A young lady with a rare Bombay (Oh) blood group had two successive uneventful pregnancies. Her serum contained a potent high-titre anti-H and serological as well as chemiluminescence tests, suggesting that the antibody was haemolytic. Her husband was of the normal H status. Theoretically, both babies should have been positive for the H antigen and should have suffered from haemolytic disease of the newborn. This apparent conundrum could be owing to the weak expression of the H antigens on the infant red cells.

[Evaluation of the risk of osteoporosis in postmenopausal patients in the Hospital Luis Castelazo Ayala of the Mexican Social Security Institute, using a risk factor questionnaire]. / Evaluación del riesgo de osteoporosis en pacientes posmenopáusicas en el Hospital Luis Castelazo Ayala del IMSS, utilizando un cuestionario de factores de riesgo.

Osteoporosis has a great impact on the population due to economic and health implications. For these reasons there is great interest to find the best prevention, diagnosis and treatment criteria. Postmenopausal women are at increased risk due to estrogen deficiency that is present in this stage of life. Through an oral interview the risk of osteoporosis in postmenopausal women was evaluated. The questionnaire was applied to 150 postmenopausal patients, questioning age, ethnic group, history of rheumatoid arthritis, use of estrogenic replacement therapy and body weight. Osteoporosis risk considered when a punctuation of 6 or greater. It was found that 85 of the patients had a punctuation of 6 or greater, with a mean punctuation of 7.5, indicating the risk of osteoporosis in our population. The most important factors that increased the punctuation and the risk to present osteoporosis were body weight and the lack of estrogen replacement therapy. We consider that these kind of questionnaires may be useful to detect the population at risk for osteoporosis and in base to this the adequate exams for diagnosis must be ordered.

FPTT is a low-incidence Rh antigen associated with a "new" partial Rh D phenotype, DFR.

BACKGROUND: Several Rh D phenotypes with partial D antigens are recognized. Some partial D antigens are associated with low-incidence Rh antigens. New partial D antigens are revealed by an atypical pattern of reactions with anti-D. STUDY DESIGN AND METHODS: The reactions of D variant cells with panels of monoclonal anti-D and with antibodies to low-incidence antigens were compared to those of known D categories to identify a new Rh D phenotype. The inheritance of partial D antigens was studied by Rh phenotyping of the families of the probands. Standard serologic methods were used and family data were analyzed. RESULTS: A new Rh D phenotype, to be called DFR, was identified in 17 probands, two of whom had made anti-D. The partial D antigen carries epD3, epD4, and epD9 and lacks epD8. The presence of other D epitopes is ambiguous; different answers were obtained for the same sample with different monoclonal anti-D of the same apparent epitope specificity. The immunoglobulin class of the anti-D was important: IgG were more successful than IgM monoclonal anti-D in detecting the partial D of DFR. Family studies showed that DFR traveled with Ce more frequently than with cE. The low-incidence antigen FPTT (International Society of Blood Transfusion number 700048) was found on all DFR samples. Family studies demonstrated that FPTT is, as suspected, part of the complex Rh system. CONCLUSION: The partial D of the Rh D phenotype, DFR, is recognized by its pattern of reactions with monoclonal anti-D and its association with the low-incidence antigen FPTT, FPTT has now been numbered Rh50.

Adrenergic stimulation of bovine non-pigmented ciliary epithelial cells raises cAMP but has no effect on K+ or Cl- currents.

Freshly isolated bovine nonpigmented ciliary epithelial cells were studied using the whole-cell voltage-clamp and permeabilized patch techniques. In a study of 148 cells three classes of cell were found; those containing inward currents alone, 31%; those containing outward currents alone, 37% and those containing both inward and outward currents, 32%. The outward currents exhibited slow, delayed activation, were blocked by tetraethylammonium (TEA+) but were not effected by changes in [Cai] suggesting they are K(+)-currents similar to IK(V), the delayed rectifier. The inward currents were reduced by TEA+ and blocked by Cs+ suggesting they are inward rectifier K(+)-currents. Intracellular cAMP levels were increased by isoprenaline with a Ka of 20 nM. However, the resting membrane potential recorded from whole ciliary processes in intracellular microelectrode studies was not effected by adrenergic stimulation, neither were the leak current, the outward current nor the sustained inward current significantly effected by isoprenaline, noradrenaline or dibutyryl-cAMP in whole-cell and permeabilized patch clamp studies.

Nucletron MicroSelectron calibration and radiation survey.

The calibration of a Nucletron MicroSelectron High Dose Rate Remote Afterloader unit and the radiation survey around the facility is discussed. The radiation survey of the facility indicates that the use of an existing linear accelerator vault will provide adequate shielding. The methodologies for performing source calibration are presented.

High-output congestive failure due to arteriovenous fistula resulting from lumbar disc surgery--a case report.

A patient is described who developed high-output congestive failure following surgery to a lumbar disc. Diagnosis of arteriovenous fistula was suggested by the signs of high-output state and a continuous bruit heard over the low back scar. Confirmation was demonstrated by abdominal aortography. Corrective surgery resulted in resolution of congestive failure.

Filters for radiation reduction: a comparison.

Aluminum, yttrium, copper, and R-filters were evaluated with respect to effective beam energy, entrance radiation exposure to the skin, x-ray tube loading, and the quality of resultant radiographs. Since all filters yielded acceptable radiographs, a figure of merit was developed to determine which filter delivered the lowest entrance radiation exposure for the lowest increase in x-ray tube loading. The figure of merit indicated that the best results were obtained with the 0.1-mm Cu filter with 2 mm Al at 60-105 kVp and with the 0.2-mm Cu filter with 2 mm Al at 105-120 kVp. Cu filters produced radiographs with quality comparable to that of R- or Y filters. Cu filters are inexpensive alternatives to rare-earth filters and yielded a reduction in radiation exposure with less x-ray tube loading.

Detection of right atrial myxoma by coronary cinearteriography.

During routine coronary cinearteriography, a large, right atrial myxoma was detected in a patient with angina pectoris. It was clinically unsuspected and was found at surgery to extend partially into the left atrium.

Diagnosis of tricuspid regurgitation. Current status.

The most accepted diagnostic methods of tricuspid regurgitation (TR) are the physical examinations and the evaluation of right atrial pressure. However, these methods are not consistently diagnostic, and a "silent" form of TR has been recognized. The current status of noninvasive and invasive diagnostic techniques is reviewed.

The use of the hepatic pressure maneuver to identify the murmur of tricuspid regurgitation.

To enhance the bedside diagnosis of tricuspid regurgitation, the influence of manual pressure applied below the liver on lower left sternal border murmurs was determined in 23 patients. All 23 subjects had right ventriculograms and right atrial phonocardiograms. The sign was positive in 13 cases, including 3 who were without a Carvallo sign. The application of manual pressure below the liver is a simple and valid additional maneuver for identifying the murmur of tricuspid regurgitation.

Anatomic and clinical analysis of 96 Beall prostheses explanted over a 13-year period.

Over 13 years, 96 Beall prostheses (80 Teflon, 16 Pyrolite) explanted at surgery were examined for durability, material wear, and clinical symptoms leading to surgical indication for excision were evaluated. The Teflon valves showed progressive disc wear and notching and two cases of disc escape from the cage; the Pyrolite discs were intact in all prostheses. The Dacron-Velour covering common to both types showed dehiscence at the inlet, significantly more severe after the third implant year in the Teflon (p less than 0.005) than in the Pyrolite prostheses. Sixty-nine (85 percent) cases with Teflon valves showed clinical manifestations of congestive heart failure due to prosthetic dysfunction; in 50 there was significant hemolytic anemia. Seven (44 percent) of the 16 Pyrolite disc valves were excised primarily because of dysfunction. The degree of hemolysis with the Pyrolite valves was usually mild. These data clearly suggested the advisability of early excision of the Beall Teflon prostheses in symptomatic patients and a close follow-up in patients with the Pyrolite models.

The relationship of carotid sinus stimulation to exercise testing.

This review is an attempt to demonstrate the safety and usefulness of the simple maneuver of carotid sinus stimulation with selected subjects undergoing exercise tests. In a variety of circumstances the addition of CSP before or after treadmill walking can yield clinically relevant information relating to arrhythmias, conduction disturbances, symptoms, and pacemakers. Further applications and benefits of these combined procedures remain to be clarified and expanded for judicious application with attention to safeguards.