V/Q mismatch without pulmonary emboli in children with histoplasmosis

In two children with histoplasmosis pulmonary perfusion and ventilation studies revealed mismatched abnormalities characterized by almost unilaterally absent perfusion but normal ventilation in the right lung. Chest roentgenograms demonstrated right hilar enlargement and pulmonary contrast angiograms revealed narrowing of the right pulmonary arteries by extrinsic fibrotic granulomata but no pulmonary emboli were present. Fibrosing mediastinitis due to histoplasmosis was found by mediastinoscopic examination in one of the patients. Non-embolic causes of V/Q mismatch lung imaging are discussed briefly, and the correlation with clinical findings is stressed for the diagnosis of pulmonary emboli.     

Treatment of saline wastewater contaminated with hydrocarbons by the photo-Fenton process

The application of the photo-Fenton process to the treatment of saline wastewater contaminated with hydrocarbons is investigated. Aqueous saline solutions containing raw gasoline were used as a model oil-field-produced water. The dependence on concentrations of the following reagents has been appropriately evaluated: hydrogen peroxide (100-200 mM), iron ions (0.5-1 mM), and sodium chloride (200-2000 ppm). The reactions were monitored by measurement of the absorption spectra and total organic carbon (TOC). Experimental results demonstrate that the photo-Fenton process is feasible for the treatment of wastewaters containing hydrocarbons, even in the presence of high concentrations of salt. The effect of the salt in this process is described through a series of reactions. A simple feedforward neural network model was found to correlate well the observed data for the degradation process.     

Effect of radiation and contrast media on chromosomes. Preliminary report

Measurements of chromosome aberrations or micronuclei in lymphocytes obtained from 7 patients indicate that angiocardiography produced chromosome damage corresponding to an average absorbed dose of about 50 rads. This is an order of magnitude larger than was estimated from the exposure rate. Experiments on lymphocytes suspended in solutions of methylglucamine and sodium diatrizoate (Renografin) or sodium diatrizoate alone (Hypaque) indicate that the chromosome damage observed in the patients is due in larger part to two effects: (a) an increased absorption of x rays as compared to blood and (b) a breakage of chromosomes even in the absence of x rays.     

Effects of phentermine on responding maintained under multiple fixed-ratio schedules of food and cocaine presentation in the rhesus monkey

Drugs that decrease drug-maintained responding at doses that do not decrease other behaviors in animals may be suitable candidates for development as medications to treat drug abuse in humans. The present study examined whether this effect could be obtained with phentermine, a drug that has been reported to decrease cocaine intake in humans. Rhesus monkeys were trained under multiple fixed-ratio 30-response schedules of food and i.v. cocaine delivery. Phentermine was always given as a slow, i.v. infusion. Acute treatment with phentermine (0.3-10 mg/kg) decreased cocaine-maintained responding at doses that did not decrease, or decreased less, food-maintained responding for each of three unit doses of cocaine (10-100 microg/kg/injection). Subacute treatment with phentermine (3 or 5.6 mg/kg, daily) also decreased cocaine-maintained responding more than food-maintained responding. After subacute treatment was terminated, rates of cocaine-maintained responding generally recovered to levels comparable to those seen during untreated control sessions. Phentermine (0.3-3 mg/kg) did not generally increase responding associated with a very low (1 microg/kg/injection) unit dose of cocaine, suggesting that the decrease in cocaine-maintained responding at higher unit doses was not the result of a leftward shift in the cocaine unit dose-effect function. Phentermine (0.1-3 mg/kg) decreased responding maintained by 1-[2-[bis(4-fluorophenyl) methoxy]ethyl]-4-[3-phenylpropyl] piperazine (GBR 12909) (30 microg/kg/injection) at doses similar to those that decreased food-maintained responding. These results show that phentermine is effective in decreasing cocaine self-administration and suggest that it may be an effective medication for cocaine abuse.     

Molecular cloning of a putative cyclic nucleotide-gated ion channel cDNA from Limulus polyphemus

Cyclic nucleotide-gated channels have been proposed to mediate the electrical response to light in the ventral photoreceptor cells of the horseshoe crab, Limulus polyphemus. However, a cyclic nucleotide-gated channel has not been identified from Limulus. We have cloned a putative full-length cyclic nucleotide-gated channel cDNA by screening cDNA libraries constructed from Limulus brain using a probe developed from Limulus ventral eye nerves. The putative full-length cDNA was derived from two overlapping partial cDNA clones. The open reading frame encodes 905 amino acids; the sequence shows 44% identity to that of the alpha subunit of the bovine rod cyclic GMP-gated channel over the region containing the transmembrane domains and the cyclic nucleotide binding domain. This Limulus channel has a novel C-terminal region of approximately 200 amino acids, containing three putative Src homology domain 3 binding motifs and a putative coiled-coil domain. The possibility that this cloned channel is the same as that detected previously in excised patches from the photoreceptive membrane of Limulus ventral photoreceptors is discussed in terms of its sequence and its expression in the ventral eye nerves.     

Channeling of three newly introduced antidepressants to patients not responding satisfactorily to previous treatment

OBJECTIVE: Trifluoromethane and CO are produced simultaneously during the breakdown of isoflurane and desflurane by dry CO2 absorbents. Trifluoromethane interferes with anesthetic agent monitoring, and the interference can be used as a marker to indicate anesthetic breakdown with CO production. This study tests representative types of gas monitors to determine their ability to provide a clinically useful warning of CO production in circle breathing systems. METHODS: Isoflurane and desflurane were reacted with dry Baralyme at 45 degrees C. Standardized samples of breakdown products were created from mixtures of reacted and unreacted gases to simulate the partial degrees of reaction which might result during clinical episodes of anesthetic breakdown using 1% or 2% isoflurane and 6% or 12% desflurane. These mixtures were measured by the monitors tested, and the indication of the wrong agent or a mixture of agents due to the presence of trifluoromethane was recorded and related to the CO concentration in the gas mixtures. RESULTS: When presented with trifluoromethane from anesthetic breakdown, monochromatic infrared monitors displayed inappropriately large amounts of isoflurane or desflurane. Agent identifying infrared and Raman scattering monitors varied in their sensitivity to trifluoromethane. Mass spectrometers measuring enflurane at mass to charge = 69 were most sensitive to trifluoromethane. CONCLUSION: Monochromatic infrared monitors were unable to indicate anesthetic breakdown via interference by trifluoromethane, but did indicate falsely elevated anesthetic concentrations. Agent identifying infrared and Raman monitors provided warning of desflurane breakdown via the interference of trifluoromethane by displaying the wrong agent or mixed agents, but may not be sensitive enough to warn of isoflurane breakdown Some mass spectrometers provided the most sensitive warnings to anesthetic breakdown via trifluoromethane, but additional data processing by some patients monitor units reduced their overall effectiveness.