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The activity of nitric oxide synthase (NOS) was assayed in enterocytes isolated from human duodenal biopsies to determine its role in celiac disease. Patients were categorized into groups with irritable bowel syndrome, iron-deficiency anemia, [B.sub.12]/folate deficiency, and treated and untreated celiac disease. Enterocytes isolated from all groups showed 1400W-inhibitable [Ca.sup.2+]-independent NOS activity with a pH level and temperature optimum of 9.4 and 37[degrees]C, respectively. Western blotting showed that enterocytes expressed the inducible NOS protein and proteins with nitrated tyrosine residues, the latter being indicative of nitric oxide-driven peroxynitrite and/or free-radical damage. Endothelial NOS was seen only in the lamina propria. Patients with celiac disease had higher NOS activity than other patient groups. Treatment of the condition led to a fall in activity. Enzyme-linked immunosorbent assay demonstrated cGMP production by the enterocyte fraction, but cGMP levels did not correlate with NOS activity. These results suggest that inducible NOS is constitutively expressed in human duodenal enterocytes, is increased in patients with untreated celiac disease, and is partially corrected when such patients are treated. We found no evidence to support a role for nitric oxide in the formation of cGMP within the small intestine. Furthermore, we were unable to demonstrate a role for peroxynitrite/free radical damage in the pathophysiology of celiac disease. small bowel; malabsorption; nitric oxide; peroxynitrite; guanosine 3',5'-cyclic monophosphate

Many marine bacteria produce substances that can inhibit the growth of other bacteria. In a study of 86 marine bacterial species, more than half produced some type of antibiotic against another species. Particle-associated bacteria were more likely to produce antibiotics than free-living bacteria.

Future rural economic health may rely more on amenities rooted in culture and history than on products measured in bushels and pecks. Tourism, retirement, and recreation are among the most [...]

At present many undergraduate programs in civil engineering do not include management courses, a situation that should be changed. The present methods of preparing engineering managers are discussed briefly, and recommendations made considering constraints of four-year programs and the probability that the BS will continue to be the entry level degree for civil engineers. After reviewing the characteristics of the engineering students and the requirements of an accredited program, methods of including management in the preparation of engineers in the present bachelors engineering programs are presented. An undergraduate engineering program should orient the students to the full range of activities that the practicing engineer performs so that the role of management is understood in the context of an engineering career, after which the concepts of management can be better absorbed. The preparation of the engineering manager can not be limited to the undergraduate classroom. Some formal training in management should be provided for graduates and practicing engineers, as they may not have had the opportunity or inclination to acquire all the necessary management information previously.

The uptake of 59Fe ascorbate by suspensions of human enterocytes prepared from endoscopically derived duodenal biopsies was studied, with each subject's serum ferritin concentration determined at the time of endoscopy. Iron uptake was greatest at 37 [degrees] C. Uptake increased from pH 5.5 to 7.3, before being totally inhibited at pH 9.0. However, ferrous ion concentration, determined by 3-(2-Pyridyl)-5,6-bis(4-phenyl sulfonic acid)-1,2,4-triazine, was greatest at pH 5.5 and fell over this pH range. The rate of uptake was significantly greater by enterocytes isolated from individuals with a low serum ferritin (22 ng/L). [V.sub.max] [+ or -] (SEM) was 78.7 [+ or -] 8.5 pmol Fe/([[micro]gram] DNA [multiplied by] min) in the normal group (n = 12) and 141 [+ or -] 17.2 pmol Fe/([[micro]gram]DNA [multiplied by] min) in the low ferritin group (n = 4, P < 0.008). Corresponding [K.sub.m] values were 52.5 [+ or -] 11.7 and 66.7 [+ or -] 5.1 [[micro]mol]/L, respectively (P < 0.91). Zinc, lead, cobalt and manganese added to the incubation buffer significantly lowered iron uptake into cells (unselected patients). The concentrations of each metal required to halve the uptake rate from 50 [[micro]mol]/L iron (I[C.sub.50]) were 85 [+ or -] 5 [[micro]mol]/L (Zn), 570 [+ or -] 170 [[micro]mol]/L (Pb), 1.1 [+ or -] 0.1 mmol/L (Co), and 3.8 [+ or -] 0.7 mmol/L (Mn). The results demonstrate that enterocytes isolated by this method show the characteristics of iron uptake seen in animal studies. We suggest that these cells will be useful in the study of iron uptake in humans. J. Nutr. 127: 177-183, 1997. KEY WORDS: iron * humans * intestine * absorption * trace elements

Cognitive processes significantly mediate the relationship between spatial abilities and environmental learning. As evidenced in two laboratory experiments, spatial-sequential memory has a mediatory effect on the relationship between general spatial ability and topological knowledge. Perspective-taking latency mediates the interaction between general spatial ability and Euclidean direction knowledge. The study supports a five-factor model involving basic spatial ability and environmental learning factors.

Background The safety and efficacy of rifampin among people living with human immunodeficiency virus (PLHIV) or other health conditions is uncertain. We assessed completion, safety, and efficacy of 4 months of rifampin vs 9 months of isoniazid among PLHIV or other health conditions. Methods We conducted post hoc analysis of 2 randomized trials that included 6859 adult participants with Mycobacterium tuberculosis infection. Participants were randomized 1:1 to 10 mg/kg/d rifampin or 5 mg/kg/d isoniazid. We report completion, drug-related adverse events (AE), and active tuberculosis incidence among people living with HIV; with renal failure or receiving immunosuppressants; using drugs or with hepatitis; with diabetes mellitus; consuming >1 alcoholic drink per week or current/former smokers; and with no health condition. Results Overall, 270 (3.9%) people were living with HIV (135 receiving antiretroviral therapy), 2012 (29.3%) had another health condition, and 4577 (66.8%) had no condition. Rifampin was more often or similarly completed to isoniazid in all populations. AEs were less common with rifampin than isoniazid among PLHIV (risk difference, −2.1%; 95% confidence interval [CI], −5.9 to 1.6). This was consistent for others except people with renal failure or on immunosuppressants (2.1%; 95% CI, −7.2 to 11.3). Tuberculosis incidence was similar among people receiving rifampin or isoniazid. Among participants receiving rifampin living with HIV, incidence was comparable to those with no health condition (rate difference, 4.1 per 1000 person-years; 95% CI, −6.4 to 14.7). Conclusions Rifampin appears to be safe and as effective as isoniazid across many populations with health conditions, including HIV. Clinical Trials Registration NCT00170209; NCT00931736. [ABSTRACT FROM AUTHOR]

The hyperbolic method of data analysis has been successful in examining laboratory consolidation data, where the loading conditions duplicate the theoretical assumptions. Such theories assume instantaneous loading. Several methods of modifying the time interval from the beginning of filling for predicting the progress of settlement have been applied, with the average consolidation of the clay layer reaching 50% and 90%.

The availability of wick drains has rapidly led to their replacing conventional sand drains as a means of accelerating the consolidation of soft soils. Wick drains have an oblong shape, but the available theories of radial consolidation have been derived for drains having a circular shape. What is needed to apply these theories to the design of field installations of wick drains is a method of calculating the equivalent diameter of an oblong shape. Previous investigators have suggested several equations for computing the equivalent diameter of wick drains, but they yield different results. The equivalent diameter of oblong drains is determined with an analog field plotter. The results of all methods are reviewed and then compared to published experimental values of equivalent diameters of wick drains. These values were determined from laboratory consolidation tests. Values of equivalent drain diameters backfigured from field data are discussed with respect to the influence of smear.