Characterization of a novel biocatalyst system for sulfide oxidation.

It has been demonstrated that an enrichment culture dominated by Thiomicrospira sp. CVO may be cultured on H2S(g) as an energy source under sulfide-limiting conditions in suspended culture with nitrate as the electron acceptor. Hydrogen sulfide (10,000 ppmv) was completely removed from the feed gas and oxidized to sulfate in <3 s of gas-liquid contacting time. Maximum loading of the biomass for sulfide oxidation was observed to be 5.8 mmol H2S/h-g biomass protein, comparable to that reported previously for Thiobacillus denitrificans under similar conditions. However, the enrichment culture was shown to be more tolerant of extremes in pH and elevated temperature than T. denitrificans. Coupled with a reported tolerance of CVO for up to 10% NaCl, these observations suggest that a CVO-based culture is potentially a more robust biocatalyst system for sulfide oxidation than cultures based on Thiobacilli.

Microbial dynamics in oil-impacted prairie soil.

A remote site in the Tallgrass Prairie Preserve (Osage County, OK) was contaminated with crude oil by a pipeline break in 1992. In 1996, the contaminated soil was bioremediated by blending with uncontaminated soil, prairie hay, buffalo manure, and commercial fertilizers, and spreading in a shallow layer over uncontaminated soil to create a landfarm. The landfarm was monitored for two years for aerobic and anaerobic bacteria, soil gases indicative of microbial activity, and for changes in the concentration of total petroleum hydrocarbons (TPH). Levels of hydrocarbon degraders and soil gas indicators of aerobic degradation were stimulated in the landfarm during the first warm season relative to uncontaminated prairie soil. However, these same indicators were less conclusive during the second warm season, indicating depletion of the more easily degradable hydrocarbons, although the landfarm still contained 6,800 mg/kg TPH on the average at the beginning of the second warm season. Methane formation and methanogen counts were clearly stimulated in the first warm season relative to uncontaminated prairie soil, indicating that methanogenesis plays an important role in the mineralization of hydrocarbons even in these shallow soils.

Exercise-induced weakness in paramyotonia congenita: exacerbation with thyrotoxicosis.

Weakness after exercise is not a commonly recognized major symptom of paramyotonia congenita. A patient with classic paramyotonia congenita developed thyrotoxicosis and severe weakness after exercise. This symptom resolved after the thyrotoxicosis was treated.

Inclusion body myositis and chronic immune thrombocytopenia.

We report a case of inclusion body myositis and chronic immune thrombocytopenia with serum platelet antibodies and circulating immune complexes. Although immune mechanisms probably play an important role in the pathogenesis of inclusion body myositis, a viral etiology cannot be excluded.

Posttraumatic syringomyelia with paroxysmal episodes of unconsciousness.

A 41-year-old man survived 23 years with quadriplegia following a C-5 fracture dislocation. During the last four months of his life he had paroxysmal episodes of unconsciousness. Necropsy disclosed a posttraumatic syrinx. The cyst extended caudally to the midlumbar region and rostrally into the midline of the medulla without communication into the fourth ventricle. Central apnea due to expansion of the cyst in the medullary respiratory centers is postulated as the possible cause of his paroxysmal episodes of unresponsiveness.

Myokymia in Guillain-Barré syndrome.

Facial or limb myokymia was present in 8 patients (17%) of 48 consecutive cases of Guillain-Barré syndrome. It occurred early in the course of the illness and persisted 5 to 40 days as the patients recovered. Facial myokymia usually occurred in clinically weak muscles, was most often bilateral, and was more common in women. Bilaterality and transient nature differed from the facial myokymia seen in pontine tumors and demyelinating disease.

The constellation of adult acid maltase deficiency: clinical, electrophysiologic, and morphologic features.

This report outlines the clinical, electrophysiologic, and morphologic findings in seven patients with adult acid maltase deficiency. The diagnosis was confirmed biochemically in four of these individuals. Adult acid maltase deficiency must be considered whenever clinical diagnoses of polymyositis, especially the chronic form, and limb-girdle muscular dystrophy are being entertained.

Calcium effect on generation and amplification of myokymic discharges.

Maneuvers designed to manipulate ionized calcium (Ca++) were carried out in two patients with inflammatory polyradiculoneuropathy and myokymia. Increased clinical myokymia and myokymic burst amplification occurred when ionized Ca++ was lowered by plasma exchange or hyperventilation. Increasing ionized Ca++ (by intravenous infusion of CaCl2) decreased the myokymia. These findings indicate that myokymic discharges are altered by changes in serum ionized Ca++ and effects on axonal excitability.