The relationship between epilithic periphyton (biofilm) bound metals and metals bound to sediments in freshwater systems.

Surficial sediments and epilithic periphyton (biofilm) were sampled from six sites on the River Churnet and five sites on the River Manifold in Staffordshire and analysed for cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn). The sites demonstrated a wide range of sediment trace metal concentrations determined by inductively coupled plasma optical emission spectrometry (ICP-OES) and atomic absorbtion spectroscopy (AAS). Biofilm was removed from the substrate using physical abrasion and 0.005 M ethylenediaminoethanetetra-acetic acid (EDTA) extractant. The European Standards, Measurements and Testing Programmes (BCR) operationally defined geochemical speciation scheme was used to determine the exchangeable, acid soluble fraction of the sediments. Significant positive correlations were determined between the EDTA extractable biofilm and the exchangeable sediment fraction for Cd, Cu and Zn but not for Pb. Natural epilithic periphyton may be a potential metal biomonitor particularly of Cu, Cd and Zn in aquatic systems and provide supporting information in relation to potential sediment toxicity.

Infected total knee arthroplasty due to Actinomyces naeslundii.

A case of a total knee arthroplasty infection with Actinomyces naeslundii is described. The difficulties of therapeutic decision-making are emphasized.

Aspergillosis among people infected with human immunodeficiency virus: incidence and survival. Adult and Adolescent Spectrum of HIV Disease Project.

Aspergillosis is a life-threatening fungal infection in immunocompromised people, including people infected with human immunodeficiency virus (HIV). We determined the incidence of aspergillosis among HIV-infected people and survival after aspergillosis diagnosis by use of a national HIV surveillance database. Among 35,252 HIV-infected patients, the incidence of aspergillosis was 3.5 cases per 1000 person-years (p-y; 95% confidence interval [CI], 3.0-4.0 per 1000 p-y). Incidence was higher among people aged > or =35 years (4.1 per 1000 p-y, 95% CI, 3. 5-4.8), among people with CD4 counts of 50-99 cells/mm(3) (5.1 per 1000 p-y, 95% CI, 2.8-7.3), or CD4 counts of <50 cells/mm(3) (10.2 per 1000 p-y, 95% CI, 8.0-12.2), versus people with CD4 counts of >200 cells/mm(3), people with > or =1 acquired immune deficiency syndrome-defining opportunistic illness (8.6 per 1000 p-y, 95% CI, 7.4-9.9), and people who were prescribed at least one medication associated with neutropenia (27.7 per 1000 p-y, 95% CI, 21.0-34.3). Median survival time after diagnosis of aspergillosis was 3 months, and 26% survived for > or =1 year. These findings suggest that aspergillosis is uncommon, occurs especially among severely immunosuppressed or leukopenic HIV-infected people, and is associated with poor survival.

Effects of one year of supplementation with zinc and other micronutrients on cellular immunity in the elderly.

The objective of this study was to determine the effects of a year of Zn supplementation on Zn concentrations in circulating cells and on cellular immune functions in the elderly. Subjects, aged 60-89, were given a placebo, 15 mg Zn, or 100 mg Zn daily for 12 months. All subjects also received a multivitamin/mineral supplement that contained no additional Zn. Blood samples were drawn and immune functions assessed prior to and at 3, 6, 12, and 16 months after beginning Zn supplementation. Subject diets were also assessed at each visit. Dietary folate, pyridoxine, alpha-tocopherol, copper, zinc, and magnesium were consistently below recommended intakes. Although plasma Zn increased significantly in the 100 mg Zn treatment group, concentrations of Zn in erythrocytes, mononuclear cells, polymorphonuclear leukocytes, and platelets were not significantly increased by zinc supplementation. Natural killer cell activity was transiently enhanced by the 100 mg/day dose of Zn. There was a progressive improvement in delayed dermal hypersensitivity (DDH) and in lymphocyte proliferative responses to two mitogens; this may have been due to one or more components of the multivitamin/mineral supplement administered to all study subjects. The enhancement of DDH was significantly greater in the placebo group than in either zinc treatment group. Thus, zinc had a beneficial effect on one measure of cellular immune function while simultaneously having an adverse effect on another measure of cellular immunity.

Zinc and immunocompetence in elderly people: effects of zinc supplementation for 3 months.

One hundred and three apparently healthy elderly subjects age 60-89 y were randomly assigned to one of three treatments: placebo, 15 mg zinc/d, or 100 mg Zn/d for 3 mo. Plasma Zn was significantly increased only in the 100 mg Zn group. Zn concentrations in erythrocytes, platelets, mononuclear cells, and polymorphonuclear leukocytes were not significantly increased by any treatment. None of the treatments significantly altered delayed dermal hypersensitivity (DDH) to a panel of seven recall antigens or in vitro lymphocyte proliferative responses (LPR) to mitogens and antigens. Fifteen subjects had initially poor lymphocyte proliferative responses that improved in 14 of these individuals during the study; this was not due to Zn supplementation but might have been caused by one or more components of a vitamin-mineral supplement administered to all study subjects.

Zinc and immunocompetence in the elderly: baseline data on zinc nutriture and immunity in unsupplemented subjects.

Zinc nutriture and immune function were studied in 100 subjects, age 60-89 yr. Mean (+/- SD) zinc concentrations found were 84.8 +/- 15.5 micrograms/dL (13.0 +/- 2.4 microM) for plasma, 1.04 +/- 0.24 micrograms (0.016 +/- 0.004 mumol)/10(9) cells for erythrocytes, 4.06 +/- 1.85 micrograms (0.062 +/- 0.028 mumol)/10(9) cells for mononuclear cells, 3.91 +/- 1.77 micrograms (0.060 +/- 0.027 mumol)/10(9) cells for polymorphonuclear leukocytes, 0.53 +/- 0.39 micrograms (0.0081 +/- 0.0060 mumol)/10(9) cells for platelets, and 222 +/- 101 micrograms (3.39 +/- 1.54 mumol)/g for hair. Zinc ingestion was below the RDA in more than 90% of study subjects. The incidence of anergy to a panel of seven skin test antigens was 41%; responses to these antigens were significantly associated with the plasma zinc concentration. Subjects with depressed lymphocyte responses to mitogens had significantly lower platelet and significantly higher mononuclear cell zinc concentrations than those with normal responses.

Effect of selenium and molybdenum on methylbenzylnitrosamine-induced esophageal lesions and tissue trace metals in the rat.

Thirty-six weanling male Sprague-Dawley rats were randomly assigned to one of four treatment groups: SE rats received 4.0 ppm selenium as sodium selenite in drinking water containing 1% sucrose; 15MO rats received 15 ppm molybdenum as sodium molybdate in the drinking water; 45MO rats received 45 ppm molybdenum in their water; and CON rats received distilled-deionized water containing only 1% sucrose. The esophageal carcinogen methylbenzylnitrosamine (MBN) was administered intragastrically in 10% ethanol twice per week for 5 wk at a dose of 2.5 mg/kg. MBN dosing was followed by a 12-wk period for tumor promotion. After this, heart, lungs, liver, spleen, kidneys, testes, tibia, muscle, brain and esophagus were excised. The esophagus was examined for MBN-induced lesions using dissecting and light microscopes and a portion was analyzed for Se. All other tissues were analyzed for Cu, Zn, Fe and Mn; some were also analyzed for Se and Mo. Most rats had precancerous lesions, and all rats had papillomas. There were no significant differences among the four treatment groups in the incidence and number per rat of precancerous lesions or gross papillomas. The SE group had significantly fewer carcinomas per rat than the other groups. The SE rats exhibited a number of significant differences in tissue trace element concentrations; in particular, they had higher Fe concentrations in heart, kidney and spleen than the other rats. The SE rats also had significantly greater urinary excretion of Mn and Fe, and excretion of the latter elements was significantly correlated with that of selenium.(ABSTRACT TRUNCATED AT 250 WORDS)