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Biomedical subjects

G S Kelly

Publications and source records attributed to G S Kelly.

14 recordsLinked to original sources
PubMed2001

Rhodiola rosea: a possible plant adaptogen.

Rhodiola rosea is a popular plant in traditional medical systems in Eastern Europe and Asian with a reputation for stimulating the nervous system, decreasing depression, enhancing work performance, eliminating fatigue, and preventing high altitude sickness. Rhodiola rosea has been categorized as an adaptogen by Russian researchers due to its observed ability to increase resistance to a variety of chemical, biological, and physical stressors. Its claimed benefits include antidepressant, anticancer, cardioprotective, and central nervous system enhancement. Research also indicates great utility in asthenic conditions (decline in work performance, sleep difficulties, poor appetite, irritability, hypertension, headaches, and fatigue) developing subsequent to intense physical or intellectual strain. The adaptogenic, cardiopulmonary protective, and central nervous system activities of Rhodiola rosea have been attributed primarily to its ability to influence levels and activity of monoamines and opioid peptides such as beta-endorphins.

Cardiovascular Diseases↗
PubMed2001

Conjugated linoleic acid: a review.

Conjugated linoleic acid (CLA) refers to a group of positional and geometric isomers of the omega-6 essential fatty acid linoleic acid (cis-9, cis-12, octadecadienoic acid). In humans evidence is currently ambiguous as to whether CLA supplementation has a significant effect on body composition. Despite favorable changes in lipid levels in animal models, a beneficial effect in humans has not yet been established. While some of the changes reported are consistent with an improved lipid profile, declines in HDL and increases in lipoprotein (a) have also been observed in some subjects. Available evidence suggests CLA supplementation has no impact on immune system performance in healthy subjects.

Animals↗
PubMed2001

Metabolic and immunologic consequences of ABH secretor and Lewis subtype status.

Determining ABH secretor phenotype and/or Lewis (Le) blood group status can be useful to the metabolically-oriented clinician. For example, differences in ABH secretor status drastically alter the carbohydrates present in body fluids and secretions; this can have profound influence on microbial attachment and persistence. Lewis typing is one genetic marker which might help identify subpopulations of individuals genetically prone to insulin resistance, autoimmunity, and heart disease. Understanding the clinical significance of ABH secretor status and the Lewis blood groups can provide insight into seemingly unrelated aspects of physiology, including variations in intestinal alkaline phosphatase activity, propensities toward blood clotting, reliability of some tumor markers, the composition of breast milk, and several generalized aspects of the immune function. Since the relevance of ABH blood group antigens as tumor markers and parasitic/bacterial/viral receptors and their association with immunologically important proteins is now well established, the prime biologic role for ABH blood group antigens may well be independent and unrelated to the erythrocyte.

ABO Blood-Group System↗
PubMed2000

Insulin resistance: lifestyle and nutritional interventions.

Insulin resistance appears to be a common feature and a possible contributing factor to several frequent health problems, including type 2 diabetes mellitus, polycystic ovary disease, dyslipidemia, hypertension, cardiovascular disease, sleep apnea, certain hormone-sensitive cancers, and obesity. Modifiable factors thought to contribute to insulin resistance include diet, exercise, smoking, and stress. Lifestyle intervention to address these factors appears to be a critical component of any therapeutic approach. The role of nutritional and botanical substances in the management of insulin resistance requires further elaboration; however, available information suggests some substances are capable of positively influencing insulin resistance. Minerals such as magnesium, calcium, potassium, zinc, chromium, and vanadium appear to have associations with insulin resistance or its management. Amino acids, including L-carnitine, taurine, and L-arginine, might also play a role in the reversal of insulin resistance. Other nutrients, including glutathione, coenzyme Q10, and lipoic acid, also appear to have therapeutic potential. Research on herbal medicines for the treatment of insulin resistance is limited; however, silymarin produced positive results in diabetic patients with alcoholic cirrhosis, and Inula racemosa potentiated insulin sensitivity in an animal model.

Complementary Therapies↗
PubMed2000

Peripheral metabolism of thyroid hormones: a review.

Peripheral metabolism of thyroid hormones is a critical component of the impact these hormones have on intracellular function. Thyroid hormones can be metabolized in peripheral tissue by deiodination, conjugation, deamination, and decarboxylation enzyme reactions. Therefore, alterations in these metabolic pathways might significantly impact the quantity of specific thyroid hormone metabolites influencing function at the cellular level. Available evidence also suggests that, under some circumstances, the activity of hepatic antioxidant enzyme systems and lipid peroxidation might influence the peripheral metabolism of thyroid hormones. Several syndromes, such as "euthyroid sick syndrome" and "low T3 syndrome," have been classified within the medical literature. The common feature of these disorders is a low level of circulating T3, with generally normal to slightly elevated blood T4 levels and either normal or slightly suppressed TSH levels. This pattern of altered thyroid hormone levels is generally agreed to be a result of impairment in extra-thyroidal peripheral metabolism. Hepatic and renal pathology, as well as catabolic states such as those induced subsequent to severe injury, illness, or trauma result in consistent shifts in the thyroid hormone profile, secondary to their impact on peripheral enzyme pathways. Lifestyle factors, such as stress, caloric restriction, and exercise, influence peripheral metabolism of thyroid hormones. Exposure to toxic metals, chemical poisons, and several drugs can also influence the peripheral fate of thyroid hormones. While the role of vitamins, minerals, and botanical extracts in thyroid hormone metabolism requires further elucidation, current evidence supports a role for selenium in the hepatic 5'-deiodination enzyme.

Energy Intake↗
PubMed1999

Larch arabinogalactan: clinical relevance of a novel immune-enhancing polysaccharide.

Larch arabinogalactan is composed of greater than 98-percent arabinogalactan, a highly branched polysaccharide consisting of a galactan backbone with side-chains of galactose and arabinose sugars. Larch arabinogalactan is an excellent source of dietary fiber, and has been approved as such by the FDA. It has been shown to increase the production of short-chain fatty acids, principally butyrate and propionate, and has been shown to decrease the generation and absorption of ammonia. Evidence also indicates human consumption of larch arabinogalactan has a significant effect on enhancing beneficial gut microflora, specifically increasing anaerobes such as Bifidobacteria and Lactobacillus. Larch arabinogalactan has several interesting properties which appear to make it an ideal adjunctive supplement to consider in cancer protocols. Experimental studies have indicated larch arabinogalactan can stimulate natural killer (NK) cell cytotoxicity, enhance other functional aspects of the immune system, and inhibit the metastasis of tumor cells to the liver. The immune-enhancing properties also suggest an array of clinical uses, both in preventive medicine, due to its ability to build a more responsive immune system, and in clinical medicine, as a therapeutic agent in conditions associated with lowered immune function, decreased NK activity, or chronic viral infection.

Dietary Fiber↗
PubMed1999

Nutritional and botanical interventions to assist with the adaptation to stress.

Prolonged stress, whether a result of mental/emotional upset or due to physical factors such as malnutrition, surgery, chemical exposure, excessive exercise, sleep deprivation, or a host of other environmental causes, results in predictable systemic effects. The systemic effects of stress include increased levels of stress hormones such as cortisol, a decline in certain aspects of immune system function such as natural killer cell cytotoxicity or secretory-IgA levels, and a disruption of gastrointestinal microflora balance. These systemic changes might be a substantial contributor to many of the stress-associated declines in health. Based on human and animal research, it appears a variety of nutritional and botanical substances - such as adaptogenic herbs, specific vitamins including ascorbic acid, vitamins B1 and B6, the coenzyme forms of vitamin B5 (pantethine) and B12 (methylcobalamin), the amino acid tyrosine, and other nutrients such as lipoic acid, phosphatidylserine, and plant sterol/sterolin combinations - may allow individuals to sustain an adaptive response and minimize some of the systemic effects of stress.

Humans↗
PubMed1999

Squalene and its potential clinical uses.

Squalene, an isoprenoid compound structurally similar to beta-carotene, is an intermediate metabolite in the synthesis of cholesterol. In humans, about 60 percent of dietary squalene is absorbed. It is transported in serum generally in association with very low density lipoproteins and is distributed ubiquitously in human tissues, with the greatest concentration in the skin, where it is one of the major components of skin surface lipids. Squalene is not very susceptible to peroxidation and appears to function in the skin as a quencher of singlet oxygen, protecting human skin surface from lipid peroxidation due to exposure to UV and other sources of ionizing radiation. Supplementation of squalene to mice has resulted in marked increases in cellular and non-specific immune functions in a dose-dependent manner. Squalene may also act as a "sink" for highly lipophilic xenobiotics. Since it is a nonpolar substance, it has a higher affinity for un-ionized drugs. In animals, supplementation of the diet with squalene can reduce cholesterol and triglyceride levels. In humans, squalene might be a useful addition to potentiate the effects of some cholesterol-lowering drugs. The primary therapeutic use of squalene currently is as an adjunctive therapy in a variety of cancers. Although epidemiological, experimental and animal evidence suggests anti-cancer properties, to date no human trials have been conducted to verify the role this nutrient might have in cancer therapy regimens.

Animals↗
PubMed1998

Clinical applications of N-acetylcysteine.

N-acetylcysteine (NAC), the acetylated variant of the amino acid L-cysteine, is an excellent source of sulfhydryl (SH) groups, and is converted in the body into metabolites capable of stimulating glutathione (GSH) synthesis, promoting detoxification, and acting directly as free radical scavengers. Administration of NAC has historically been as a mucolytic agent in a variety of respiratory illnesses; however, it appears to also have beneficial effects in conditions characterized by decreased GSH or oxidative stress, such as HIV infection, cancer, heart disease, and cigarette smoking. An 18-dose oral course of NAC is currently the mainstay of treatment for acetaminophen-induced hepatotoxicity. N-acetylcysteine also appears to have some clinical usefulness as a chelating agent in the treatment of acute heavy metal poisoning, both as an agent capable of protecting the liver and kidney from damage and as an intervention to enhance elimination of the metals.

Acetylcysteine↗
PubMed1998

The role of glucosamine sulfate and chondroitin sulfates in the treatment of degenerative joint disease.

Successful treatment of osteoarthritis must effectively control pain, and should slow down or reverse progression of the disease. Biochemical and pharmacological data combined with animal and human studies demonstrate glucosamine sulfate is capable of satisfying these criteria. Glucosamine sulfate's primary biological role in halting or reversing joint degeneration appears to be directly due to its ability to act as an essential substrate for, and to stimulate the biosynthesis of, the glycosaminoglycans and the hyaluronic acid backbone needed for the formation of proteoglycans found in the structural matrix of joints. Chondroitin sulfates, whether they are absorbed intact or broken into their constituent components, similarly provide additional substrates for the formation of a healthy joint matrix. Evidence also supports the oral administration of chondroitin sulfates for joint disease, both as an agent to slowly reduce symptoms and to reduce the need for non-steroidal anti-inflammatory drugs. The combined use of glucosamine sulfate and chondroitin sulfates in the treatment of degenerative joint disease has become an extremely popular supplementation protocol in arthritic conditions of the joints. Although glucosamine sulfate and chondroitin sulfates are often administered together, there is no information available to demonstrate the combination produces better results than glucosamine sulfate alone.

Chondroitin Sulfates↗
PubMed1998

Folates: supplemental forms and therapeutic applications.

Folates function as a single carbon donor in the synthesis of serine from glycine, in the synthesis of nucleotides form purine precursors, indirectly in the synthesis of transfer RNA, and as a methyl donor to create methylcobalamin, which is used in the re-methylation of homocysteine to methionine. Oral folates are generally available in two supplemental forms, folic and folinic acid. Administration of folinic acid bypasses the deconjugation and reduction steps required for folic acid. Folinic acid also appears to be a more metabolically active form of folate, capable of boosting levels of the coenzyme forms of the vitamin in circumstances where folic acid has little to no effect. Therapeutically, folic acid can reduce homocysteine levels and the occurrence of neural tube defects, might play a role in preventing cervical dysplasia and protecting against neoplasia in ulcerative colitis, appears to be a rational aspect of a nutritional protocol to treat vitiligo, and can increase the resistance of the gingiva to local irritants, leading to a reduction in inflammation. Reports also indicate that neuropsychiatric diseases secondary to folate deficiency might include dementia, schizophrenia-like syndromes, insomnia, irritability, forgetfulness, endogenous depression, organic psychosis, peripheral neuropathy, myelopathy, and restless legs syndrome.

Folic Acid↗
PubMed1998

L-Carnitine: therapeutic applications of a conditionally-essential amino acid.

A trimethylated amino acid roughly similar in structure to choline, carnitine is a cofactor required for transformation of free long-chain fatty acids into acylcarnitines, and for their subsequent transport into the mitochondrial matrix, where they undergo beta-oxidation for cellular energy production. Mitochondrial fatty acid oxidation is the primary fuel source in heart and skeletal muscle, pointing to the relative importance of this nutrient for proper function in these tissues. Although L-carnitine deficiency is an infrequent problem in a healthy, well-nourished population consuming adequate protein, many individuals within the population appear to be somewhere along a continuum, characterized by mild deficiency at one extreme, and tissue pathology at the other. Conditions which seem to benefit from exogenous supplementation of L-carnitine include anorexia, chronic fatigue, coronary vascular disease, diphtheria, hypoglycemia, male infertility, muscular myopathies, and Rett syndrome. In addition, preterm infants, dialysis patients, and HIV+ individuals seem to be prone to a deficiency of L-carnitine, and benefit from supplementation. Although available data on L-carnitine as an ergogenic aid is not compelling, under some experimental conditions pretreatment has favored aerobic processes and resulted in improved endurance performance.

Carnitine↗
PubMed1989

'Brittle' diabetes.

Explore the source record for details and available documents.

Diabetes Mellitus, Type 1↗