Biaryl ethers as potent allosteric inhibitors of reverse transcriptase and its key mutant viruses: Aryl substituted pyrazole as a surrogate for the pyrazolopyridine motif

Biaryl ethers were recently reported as potent NNRTIs. Herein, we disclose a detailed effort to modify the previously reported compound 1. We have designed and synthesized a series of novel pyrazole derivatives as a surrogate for pyrazolopyridine motif that were potent inhibitors of HIV-1 RT with nanomolar intrinsic activity on the WT and key mutant enzymes and potent antiviral activity in infected cells.     

Characterization of the tuberculous granuloma in murine and human lungs: cellular composition and relative tissue oxygen tension

The granulomatous reaction is the hallmark of the host response to infection with Mycobacterium tuberculosis. Despite its apparent importance to host defence against the tubercle bacillus, the granulomatous response remains to be completely defined. The present study used histological, immunohistochemical and flow-cytometric analyses to characterize pulmonic granulomatous tissues of tuberculous mice and humans. The kinetics of recruitment of neutrophils, macrophages, dendritic cells, and T and B lymphocytes into the lungs of mice infected aerogenically with the virulent Erdman strain of M. tuberculosis was evaluated in detail in both the acute and persistent phase of infection. A hypoxia-sensing compound based on the 2-nitroimidazole structure (EF5), together with immunohistochemical studies targeting endothelial cells were used to examine the relative oxygen tension in tuberculous granulomatous tissues in mice. The results have provided evidence that: (i) the granulomatous tissues are a highly organized structure whose formation is regulated by orderly recruitment of specific immune cells exhibiting distinct spatial relationship with one another; (ii) the granulomatous reaction, at least in the mouse, may represent an exaggerated response to the tubercle bacillus that can play a role in the development of immunopathology; (iii) B lymphoid aggregates are a prominent feature in both murine and human granulomatous tissues, although the immune cells that are most prominently associated with these clusters vary among the two species; (iv) murine tuberculous granulomatous tissues are relatively aerobic, suggesting that mouse models of persistent tuberculosis may not be suitable for the study of any hypoxic response of M. tuberculosis.     

Chemical and Biological Interactions during Nitrate and Goethite Reduction by Shewanella putrefaciens 200

Although previous research has demonstrated that NO₃⁻ inhibits microbial Fe(III) reduction in laboratory cultures and natural sediments, the mechanisms of this inhibition have not been fully studied in an environmentally relevant medium that utilizes solid-phase, iron oxide minerals as a Fe(III) source. To study the dynamics of Fe and NO₃⁻ biogeochemistry when ferric (hydr)oxides are used as the Fe(III) source, Shewanella putrefaciens 200 was incubated under anoxic conditions in a low-ionic-strength, artificial groundwater medium with various amounts of NO₃⁻ and synthetic, high-surface-area goethite. Results showed that the presence of NO₃⁻ inhibited microbial goethite reduction more severely than it inhibited microbial reduction of the aqueous or microcrystalline sources of Fe(III) used in other studies. More interestingly, the presence of goethite also resulted in a twofold decrease in the rate of NO₃⁻ reduction, a 10-fold decrease in the rate of NO₂⁻ reduction, and a 20-fold increase in the amounts of N₂O produced. Nitrogen stable isotope experiments that utilized δ¹⁵N values of N₂O to distinguish between chemical and biological reduction of NO₂⁻ revealed that the N₂O produced during NO₂⁻ or NO₃⁻ reduction in the presence of goethite was primarily of abiotic origin. These results indicate that concomitant microbial Fe(III) and NO₃⁻ reduction produces NO₂⁻ and Fe(II), which then abiotically react to reduce NO₂⁻ to N₂O with the subsequent oxidation of Fe(II) to Fe(III).     

A rapid and sensitive radiochemical assay for phosphatidic acid phosphohydrolase activity.

A technique is described for the radiochemical assay of phosphatidic acid phosphohydrolase activity in rat brain. Radiochemically pure 32P-labeled phosphatidic acid of known specific radioactivity and structure, which was biosynthesized in vitro by the diacylglycerol kinase of E. coli, was used as the substrate. As little as 5 microgram of microsomal or mitochondrial protein can be used for the assay, and product formation in the picomole range can be determined accurately. This procedure should be useful in situations where only limited amounts of tissue are available.     

Morphological and physiological responses of the lungs of dogs to acute decompression

The lung's response to decompression was studied in dogs anesthetized with pentobarbital sodium. Arterial pressure, hematocrit, right ventricular pressure, left ventricular end-diastolic pressure (LVEDP), dynamic compliance (CL), pulmonary resistance (RL), and arterial PO2, PCO2, and pH were measured prior to and for 3 h after a simulated air dive to 300 feet of seawater. Bronchoscopy was performed predive and at 3 h postdive. At 3 h animals were killed, and sections of lung were excised for histological examination. The decompression profile used regularly produced pulmonary hypertension, systemic hypotension, hemoconcentration, and arterial hypoxemia. CL fell in all but one dived animal. RL was more variable but remained unchanged postdive in most animals. The decompression stress did not alter the bronchoscopic and histological appearance of the airway mucosa. Pulmonary edema was regularly observed in histological sections and occurred without elevations of LVEDP. We concluded that noncardiac pulmonary edema is the principal response of the lung to decompression stress.     

Optimized preparation and determination of pea seedling diamine oxidase

The level of diamine oxidase in pea seedling stems has been determined as a function of time after germination in both etiolated and non-etiolated plants. The maximum amount of enzyme per plant is obtained between 11 and 13 days. The amount of activity per gram of tissue appears to be proportional to the rate of growth. We describe an efficient method of isolation of pea seedling stem diamine oxidase from 12-day-old etiolated seedlings, a procedure that brings the enzyme to purity after a 97-fold purification. A new assay procedure for pea seedling diamine oxidase is detailed and compared to previously used methods. The kinetic parameters for three common substrates have also been determined. SDS-acrylamide gel electrophoresis, gel filtration chromatography and copper analyses have been used to determine that pea seedling diamine oxidase exists as a dimer of two apparently identical subunits, the dimer molecular weight being about 190,000. The isoelectric point of this enzyme was determined to be 6.5.