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Biomedical subjects

G N Schrauzer

Publications and source records attributed to G N Schrauzer.

At least 19 recordsLinked to original sources
PubMed2006

Interactive effects of selenium and chromium on mammary tumor development and growth in MMTV-infected female mice and their relevance to human cancer.

Evidence for interactive effects of chromium and selenium on the appearance of mammary tumors was obtained by exposing female virgin C3H mice infected with the murine mammary tumorvirus (MMTV) to subtoxic levels of Cr [as Cr(III) nitrate] and Se (as sodium selenite) in the supply water. Cr counteracted the inhibitory effect of Se on tumor development in a dose-dependent manner, shortened the tumor latency period, and accelerated tumor growth rates. Exposure to Cr also altered the levels of Se in the liver and kidneys of the mice, indicating that Cr interacts with Se and affects its organ distribution. Chromium must be added to the list of Se-antagonistic elements that weaken or abolish the antitumorigenic effects of Se. These findings are relevant to human cancer as previous studies revealed the age-corrected mortalities from breast and other major forms of cancer in different countries to be inversely correlated with the dietary Se intakes, and directly correlated with the estimated intakes of Cr and of other Se-antagonistic elements. The presence of these elements in foods must be taken into account when estimating the optimal dose of supplemental Se for cancer risk reduction.

Animals↗
PubMed2001

Nutritional selenium supplements: product types, quality, and safety.

Selenium supplements contain selenium in different chemical forms. In the majority of supplements, the selenium is present as selenomethionine. However, in multivitamin preparations, infant formulas, protein mixes, weight-loss products and animal feed, sodium selenite and sodium selenate are predominantly used. In some products, selenium is present in protein- or amino acid chelated forms; in still others, the form of selenium is not disclosed. Current evidence favors selenomethionine over the other forms of selenium. Extradietary supplementation of selenium at the dosage of 200 micrograms per day is generally considered safe and adequate for an adult of average weight subsisting on the typical American diet.

Anticarcinogenic Agents↗
PubMed2000

Anticarcinogenic effects of selenium.

Selenium (Se) exerts its anticarcinogenic effects by multiple mechanisms. In the physiological dosage range, Se appears to function as an antimutagenic agent, preventing the malignant transformation of normal cells and the activation of oncogenes. These protective effects of Se seem to be primarily associated with its presence in the glutathione peroxidases, which are known to protect DNA and other cellular components from damage by oxygen radicals. Selenoenzymes are also known to play roles in carcinogen metabolism, in the control of cell division, oxygen metabolism, detoxification processes, apoptosis induction and the functioning of the immune system. Other modes of action, either direct or indirect, may also be operative, such as the partial retransformation of tumor cells and the inactivation of oncogenes. However, the effects of Se in the physiological dosage range are not attributable to cytotoxicity, allowing Se to be defined as a genuine nutritional cancer-protecting agent. The anticarcinogenic effects of Se are counteracted by Se-antagonistic compounds and elements. For maximal utilization of its cancer-protective potential, Se supplementation should start early in life and be maintained over the entire lifespan. In addition, exposure to Se antagonists and carcinogenic risk factors should be minimized by appropriate dietary and lifestyle changes.

Anticarcinogenic Agents↗
PubMed2000

Selenomethionine: a review of its nutritional significance, metabolism and toxicity.

Although the need for selenium in human and animal nutrition is well recognized, the question concerning the proper form of selenium for supplemental use is still being debated. Ideally, selenium should be supplemented in the form in which it occurs naturally in foods. Because the L-isomer of selenomethionine (Se-met) is a major natural food-form of selenium, synthetic L-Se-met or enriched food sources thereof such as selenium yeast are appropriate supplemental forms of Se for humans; for animals, DL-Se-met is acceptable. Ingested Se-met is either metabolized directly to reactive forms of selenium or stored in place of methionine in body proteins. Se-met metabolism is closely linked to protein turnover. At constant intakes in the nutritional range, tissue Se levels increase until a steady state is established, preventing the build-up to toxic levels.

Adult↗
PubMed2000

Treatment of secondary lymphedema of the arm with physical decongestive therapy and sodium selenite: a review.

Secondary lymphedema (LE) in the proximal extremities develop with relatively high frequency in cancer patients after tumor resection, lymph-node obliteration, and/or postoperative irradiation. Physical therapy combined with manual or mechanical lymph drainage and compression bandaging provides symptomatic relief but does prevent the progression of degenerative changes in the affected tissues. As biochemical studies have linked these changes significantly to the excessive generation of oxygen radicals in the affected tissues, LE therapy should aim to eliminate oxygen radical production. Because selenium is a functional component of antioxidant enzymes, has anti-inflammatory properties, and reduces the expression of endothelial cell adhesion molecules, its effect was investigated in postmastectomy patients with LE of the arm. Sodium selenite administered orally in isotonic solution (selenase) at oral dosages of 800 microg Se/day on days 1 through 4 and 500 microg Se/day on days 5 through 28 produced a spontaneous reduction in LE volume and normalized blood parameters in a manner consistent with diminished oxygen radical production. In a randomized, placebo-controlled, double-blind study with postmastectomy LE patients undergoing combined physical decongestion therapy (CPDT), selenite at similar dosages increased the efficacy of CPDT and improved the mobility and heat tolerance of the affected extremity. The patients in this study received 1000 microg of Se/day orally during the first week, 300 microg Se/day during the second and third weeks, and a maintenance dose of 100 microg Se/day during 3 months of follow-up. All patients remained erysipelas-free during the 3 weeks of CPDT and the 3-month follow-up period. Based on the available evidence, supplementation with sodium selenite in isotonic solution is judged to be a valuable and safe extension of the physical decongestive therapy of LE.

Arm↗
PubMed2000

Selenium, boron, and germanium deficiency in the etiology of Kashin-Beck disease.

Concentrations of selenium (Se), boron (B), and germanium (Ge) were determined in scalp hair of children with Kashin-Beck disease (KBD), in healthy children in KBD-disease endemic areas, and in healthy children in non-KBD areas. Mean Se, B, and Ge concentrations were low in children with KBD; in hair of healthy children in KBD areas, Se levels were normal but B and Ge levels were lower than in KBD-free areas. The hair levels of B and Ge were unaffected by selenium supplementation. It is suggested that B and Ge deficiency may be contributing factors in the etiology of KBD.

Adolescent↗
PubMed1995

Effects of nutritional lithium deficiency on behavior in rats.

To demonstrate whether nutritional lithium deficiency is associated with behavioral changes, male Sprague-Dawley rats were placed on a lithium-deficient diet (Li content < .01 ppm). A lithium-deprived group, receiving drinking water containing 31 microM NaCl, were compared to a control group receiving drinking water containing 31 microM LiCl. Growth and general appearance were the same in both groups. However, lithium-deficient animals demonstrated decreased aggression in social interactions with other rats and also in response to handling. The phase of wheel-running activity was delayed by 0.8 h and exhibited decreased amplitude (p < .05). Other behaviors, including acquisition and retention of a passive avoidance response, were unaffected by lithium deprivation.

Aggression↗
PubMed1994

Effects of nutritional lithium supplementation on mood. A placebo-controlled study with former drug users.

A total of 24 subjects, 16 males and 8 females, average age 29.4 +/- 6.5 y, were randomly divided into two groups. Group A received 400 micrograms/d of lithium orally, in tablets composed of a naturally lithium-rich brewer's yeast, for 4 wk. Group B was given normal, lithium-free brewer's yeast as a placebo. All the subjects of the study were former drug users (mostly heroin and crystal methamphetamine). Some of the subjects were violent offenders or had a history of domestic violence. The subjects completed weekly self-administered mood test questionnaires, which contained 29 items covering parameters measuring mental and physical activity, ability to think and work, mood, and emotionality. In the lithium group, the total mood test scores increased steadily and significantly during the period of supplementation. The 29 items were furthermore placed into three subcategories reflecting happiness, friendliness, and energy, as well as their negative counterparts. In Group A, the scores increased consistently for all subcategories until wk 4 and remained essentially the same in wk 5. In Group B, the combined mood test scores showed no consistent changes during the same period. The only positive change in some members of Group B occurred during wk 1 and was attributed to a placebo effect. In Group B, the placebo effect was noticeable for the subcategories of energy and friendliness; the happiness scores declined during the entire period of observation. Based on these results and the analysis of voluntary written comments of study participants, it is concluded that lithium at the dosages chosen had a mood-improving and -stabilizing effect.

Administration, Oral↗
PubMed1994

Selenium in the maintenance and therapy of HIV-infected patients.

Due to its antiviral effects and its importance for all immunological functions, the administration of selenium is suggested as a supportive measure in early as well as in advanced stages of HIV-induced disease. Initial observations on the effects of selenium supplementation in HIV-infected patients indicate that selenium causes symptomatic improvements and possibly slows the course of the disease. As selenium inhibits reverse transcriptase activity in RNA-virus-infected animals, supplemental selenium could also prevent the replication of HIV and retard the development of AIDS in newly HIV-infected subjects. An adequate supply of selenium and of antioxidant vitamins is also proposed as a measure to reduce the probability of the placental transmission of HIV in pregnancy.

AIDS-Related Complex↗
PubMed1992

Lithium in scalp hair of adults, students, and violent criminals. Effects of supplementation and evidence for interactions of lithium with vitamin B12 and with other trace elements.

The lithium content of human hair shows an approximately linear response to extradietary lithium supplementation at dosage levels of up to 2000 micrograms/d. From the mean hair lithium concentration of 0.063 micrograms/g in 2648 predominantly American adults, and the reference hair lithium concentrations determined in the present study, the mean lithium intakes were calculated to be 730 micrograms/d. Hair lithium concentrations were extremely low in nearly 20% of the American samples, and in samples collected in Munich, Germany and Vienna, Austria. Hair lithium levels are low in certain pathological conditions, e.g., heart disease, in learning-disabled subjects, and in incarcerated violent criminals. The highest levels were observed in samples of a lithium-treated psychiatric patient. A statistically highly significant direct association was observed between the hair lithium and cobalt concentrations, which suggests a role of lithium in the transport and distribution of vitamin B12. Interactions of lithium with other trace elements are also discussed.

Adult↗
PubMed1990

Lithium in drinking water and the incidences of crimes, suicides, and arrests related to drug addictions.

Using data for 27 Texas counties from 1978-1987, it is shown that the incidence rates of suicide, homicide, and rape are significantly higher in counties whose drinking water supplies contain little or no lithium than in counties with water lithium levels ranging from 70-170 micrograms/L; the differences remain statistically significant (p less than 0.01) after corrections for population density. The corresponding associations with the incidence rates of robbery, burglary, and theft were statistically significant with p less than 0.05. These results suggest that lithium has moderating effects on suicidal and violent criminal behavior at levels that may be encountered in municipal water supplies. Comparisons of drinking water lithium levels, in the respective Texas counties, with the incidences of arrests for possession of opium, cocaine, and their derivatives (morphine, heroin, and codeine) from 1981-1986 also produced statistically significant inverse associations, whereas no significant or consistent associations were observed with the reported arrest rates for possession of marijuana, driving under the influence of alcohol, and drunkenness. These results suggest that lithium at low dosage levels has a generally beneficial effect on human behavior, which may be associated with the functions of lithium as a nutritionally-essential trace element. Subject to confirmation by controlled experiments with high-risk populations, increasing the human lithium intakes by supplementation, or the lithiation of drinking water is suggested as a possible means of crime, suicide, and drug-dependency reduction at the individual and community level.

Behavior↗
PubMed1989

Trace elements in hair: a study of residents in Darjeeling (India) and San Diego, California (U.S.A).

Trace element contents of scalp hair from randomly selected, ethnically homogeneous subjects of Darjeeling (India) were compared with those of the residents of San Diego, California (U.S.A.). The differences between mean concentrations of Ca, Mg, Cu, Na and Cd in the two groups were not significant, and the concentrations of K, Fe, Mn and Zn were significantly higher (P less than 0.01), and that of Al was significantly lower (P less than 0.01), in hair of the residents of Darjeeling. Concentrations of lead in four of the Darjeeling hair samples were very high (greater than 30 micrograms g-1) and in the remaining samples the mean concentration was similar to San diego hair samples. In two mentally retarded Darjeeling subjects, abnormally high values of aluminum (50 and 70 micrograms g-1) and iron (155 and 196 micrograms g-1) were observed. The mean aluminum concentration (2.4 micrograms g-1) in the remaining Darjeeling hair samples was significantly lower than the mean aluminum concentration (10.6 micrograms g-1) in the San Diego hair samples (P less than 0.01). The mean manganese concentration in Darjeeling hair was 20 times higher than the mean manganese content in San Diego hair samples.

Adult↗