A prospective surgical outcome study assessing the impact of parathyroidectomy on symptoms in patients with secondary and tertiary hyperparathyroidism.

BACKGROUND: To assess the impact of surgery on preoperative symptoms in secondary (2 degrees ) and tertiary (3 degrees ) hyperparathyroidism (HPT) compared with primary (1 degrees ) HPT. METHODS: Twenty-two patients with 2 degrees HPT and 10 with 3 degrees HPT were enrolled. Age-matched patients, 32 with 1 degrees HPT and 32 with thyroid disease were enrolled for comparison. An outcome questionnaire documented symptoms expressed as the median symptom index score (MSIS) preoperatively and at days 7 and 3 and 12 months postoperatively. RESULTS: Preoperatively, the MSIS for the groups with 3 degrees, 2 degrees, and 1 degrees HPT and thyroid disease was 225, 572, 372, and 146, indicating that patients with HPT were more symptomatic than those in the thyroid group (P<.05). Patients with 1 degrees HPT had a decrease in their MSIS at day 7 (195, P<.05) and at 3 and 12 months (159 and 156). Patients with 3 degrees HPT also had a decrease in their MSIS over time. Patients with 2 degrees HPT had a decrease in their MSIS at day 7 (469, P<.05); however, they remained more symptomatic at 3 and 12 months (410 and 355). CONCLUSIONS: Parathyroidectomy reduces many of the preoperative symptoms in HPT. Patients with 1 degrees and 3 degrees HPT have a similar resolution of their symptoms. Patients with 2 degrees HPT have an improvement in many of their symptoms, although they remain more symptomatic at 1 year.

Persistence of denitrifying enzyme activity in dried soils.

The effects of air drying soil on denitrifying enzyme activity, denitrifier numbers, and rates of N gas loss from soil cores were measured. Only 29 and 16% of the initial denitrifying enzyme activity in fresh, near field capacity samples of Maury and Donerail soils, respectively, were lost after 7 days of air drying. The denitrifying activity of bacteria added to soil and activity recently formed in situ were not stable during drying. When dried and moist soil cores were irrigated, evolution of N gas began, and it maximized sooner in the dried cores. This suggests that the persistence of denitrifying enzymes permits accelerated denitrification when dried soils are remoistened. Enzyme activity increased significantly in these waterlogged cores, but fluctuations in enzyme activity were small compared with fluctuations in actual denitrification rate, and enzyme activities were always greater than denitrification rates. Apparent numbers of isolatable denitrifiers (most-probable-number counts) decreased more than enzyme activity as the soils were dried, but after the soils were rewetted, the extent of apparent growth was not consistently related to the magnitude of N loss. We hypothesize that activation-inactivation of existing enzymes by soil O(2) is of greater significance in transient denitrification events than is growth of denitrifiers or synthesis of new enzymes.

Prospective surgical outcome study of relief of symptoms following surgery in patients with primary hyperparathyroidism.

Many of the symptoms experienced by patients with primary hyperparathyroidism (HPT) develop insidiously and have often been misinterpreted as normal aging. The purpose of this study was to quantify HPT patients' preoperative symptoms prospectively and study the impact of successful surgical intervention on these symptoms. Altogether 63 consecutive patients with primary HPT and 54 comparison patients with nontoxic thyroid disease were prospectively enrolled in the study. An outcome questionnaire documenting symptoms with a visual analog scale (VAS) was used. The questionnaire was filled out preoperatively and at 7 to 10 days and 3 and 12 months postoperatively. At 1 year the questionnaire also included a general health assessment and quality of life index. Demographic data and follow-up blood work was obtained. Descriptive statistics, parametric comparisons (t-tests, ANOVA), and nonparametric comparisons (Mann-Whitney U-test) were calculated. The HPT group demonstrated a significant decrease in reported symptoms between the preoperatively assessment and 7 to 10 days after operation (p < 0.001). There were no further statistically significant decreases in the HPT group's symptoms at 3 and 12 months, but there was a trend for these symptoms to decrease over time. HPT patients perceived a 60% increase in their general health at 1 year; the comparison group perceived no increase. There was no significant change in the symptoms reported by the comparison group between each of the study intervals. Surgical intervention on HPT patients significantly reduces preoperative symptoms, and this reduction is most marked within the first 10 days after surgery.

Aerobic and anaerobic growth of rifampin-resistant denitrifying bacteria in soil.

The growth and survival of several rifampin-resistant isolates of denitrifying bacteria were examined under anaerobic (denitrifying) and aerobic conditions. Two isolates added to nonsterile Bruno soil at densities of between 10(4) and 10(6) CFU g dry soil-1 exhibited an initial period of growth followed by a gradual decline in numbers. After 28 days, both isolates maintained viable populations of between 10(4) and 10(5) CFU g dry soil-1 under both denitrifying and aerobic conditions. One of the isolates consistently grew better under denitrifying conditions, and the other isolate consistently grew better under aerobic conditions. The relative pattern of denitrifying versus aerobic growth for each organism was not affected by the addition of glucose. The growth yields of the two isolates varied with soil type, but the relative pattern of denitrifying versus aerobic growth was consistent in three soils with greatly different properties. Five of nine isolates introduced into Bruno soil at low population densities (approximately 10(5) CFU g dry soil-1) exhibited better growth after 2 days under denitrifying conditions. It was not possible to predict the prevalence of the denitrifying or aerobic mode of growth in nonsterile soil from the growth characteristics of the isolates in pure cultures or sterile soil.

Kinetics of nitrate utilization by mixed populations of denitrifying bacteria.

Kinetics of nitrate utilization by mixed bacterial populations from two agricultural soils and a pond sediment in Kentucky were measured by using progress curves of nitrous oxide production. Nitrous oxide production from anaerobic soil and sediment slurries containing added nitrate and acetylene exhibited first-order kinetics. Nitrate affinity (K(m)) for mixed populations of denitrifying bacteria in unfertilized agricultural soils and pond sediments ranged from 1.8 to 13.7 muM. The affinity of bacterial populations for nitrate did not vary with habitat, and the ability to use low concentrations of nitrate was retained by bacterial populations living in environments which received large inputs of nitrate.

Competition between Two Isolates of Denitrifying Bacteria Added to Soil.

We examined the competitive relationship between two isolates of denitrifying bacteria, both of which grow well under aerobic conditions but differ in their ability to grow under denitrifying conditions. The growth and persistence of the two isolates, added to sterile soil or added to soil previously colonized by the other isolate, were monitored under aerobic and denitrifying (anaerobic) conditions. When isolates were added together to sterile soil, the isolate added at the higher density reduced the growth of the isolate added at the lower density. The magnitude of the growth reduction varied depending on the competitive abilities of the individual isolates and the aeration state of the soil. Prior colonization of soil with one of the isolates conferred a competitive advantage on the colonized isolate but did not lead to the disappearance of the challenging isolate. Fluctuations in aeration state caused large changes in the population density of one isolate and altered the competitive relationship between the two isolates. The competitive effectiveness of each isolate varied with cell density, the degree of prior colonization of the soil by the other isolate, and the aeration state of the soil.

Dynamics of Soil Denitrifier Populations: Relationships between Enzyme Activity, Most-Probable-Number Counts, and Actual N Gas Loss.

To better understand temporal variability in soil denitrification, denitrifying enzyme activity (DEA) and denitrifier populations (as determined by most-probable-number [MPN] counts) were measured in field and laboratory experiments. Measurements of DEA and MPN provided highly contradictory indications of denitrifier dynamics. In laboratory incubations, under conditions favoring active denitrification, the synthesis of new denitrifying enzymes and the actual amount of denitrification were closely related. In other experiments, however, both DEA and MPN counts were poor indicators of actual denitrification. In some cases, we found significant increases in DEA but no significant production of N gas. Except with unnaturally high substrate amendments, changes in DEA were small relative both to the persistently high DEA background and to changes in MPN. As estimated by MPN counts, denitrifier populations increased significantly during denitrification events. It was apparent that only a small fraction of the denitrifiers were included in the MPN counts, but it appeared that this isolatable fraction increased during periods of active denitrifier growth. Use of DEA as an index of biomass of cells which have synthesized denitrifying enzymes suggested that denitrifier populations were persistent, stable, and much larger than indicated by MPN procedures.