The nutritional regulation of T lymphocyte function

Non-musculoskeletal benefits of vitamin D

The aim of this study is to determine and critically evaluate the plausible relationships of vitamin D with extra-skeletal tissues in humans. Severe vitamin D deficiency results in rickets in children and osteomalacia in adults; these beneficial effects in the musculoskeletal system and certain physiological functions are well understood. Nevertheless, mounting reports support additional beneficial effects of vitamin D, outside the musculoskeletal system. This review explores the recent advances in knowledge about the non-skeletal effects of vitamin D. Peer-reviewed papers were extracted from research databases using key words, to assess correlations between vitamin D and extra-skeletal diseases and conditions. As per the guidelines of the Preferred Reporting Items for Systematic Reviews (PRISMA); general interpretations of results are included; taking into consideration the broader evidence and implications. This review summarizes current knowledge of the effects of vitamin D status on extra-skeletal tissues with special attention given to relationships between vitamin D status and various diseases commonly affecting adults; the effects of intervention with vitamin D and exposure to sunlight. Evidence suggests that vitamin D facilitates the regulation of blood pressure; and cardiac; endothelial; and smooth muscle cell functions; playing an important role in cardiovascular protection. In addition; 1,25(OH)₂D improves immunity; subdues inflammation; and reduces the incidence and severity of common cancers; autoimmune diseases and infectious diseases. Almost all adequately powered; epidemiological and biological studies that use; adequate doses of vitamin D supplementation in D-deficient populations have reported favorable outcomes. These studies have concluded that optimizing 25(OH)D status improves the functionality of bodily systems; reduces comorbidities; improves the quality of life; and increases survival. Although accumulating evidence supports biological associations of vitamin D sufficiency with improved physical and mental functions; no definitive evidence exists from well-designed; statistically powered; randomized controlled clinical trials. Nevertheless, most studies point to significant protective effects of vitamin D in humans when the minimum 25(OH)D serum level exceeds 30ng/mL and is maintained throughout the year.

Ultra-Low Level Detection of L-Histidine Using Solution-Processed ZnO Nanorod on Flexible Substrate

This work demonstrates a novel label free and sensitive approach for the detection of L-histidine. This is a simple and reliable method for ultra-low level detection of L-histidine. All solution processed synthesizing technique was utilized to develop such type of detection scheme. Silicon substrate was replaced by normal transparent sheet to make it more facile and cost-effective detection technique. Fabricated device for L-histidine detection works upon the variation of current through the ZnO nanorod with L-histidine concentration. Operation principle strongly depends upon the electron charge transfer between metal cation and L-histidine inside the chelating complex. Morphological, structural and optical characterization of solution processed synthesized ZnO nanorod (ZnO NR) was carried out prior to sensor device fabrication. Our sensor device exhibits the sensitivity around 0.86 nA/fM and lower limit of detection (LOD) ∼ 0.1 fM(S/N=3).

A portable chemical sensor for histidine based on the strategy of click chemistry

A novel portable chemical sensor is developed in combination of the personal glucose meters (PGM) with click chemistry for sensitive and selective determination of histidine. Invertase-labeled alkynyl-DNA can be modified onto the surfaces of Streptavidin Magnespheres Paramagnetic Particles (PMPs) through copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) reaction and formed invertase-functionalized PMPs, which can be separated easily. The presence of invertase can convert sucrose to glucose and can be monitored by the PGM easily. The presence of histidine can inhibit the CuAAC, so the read-out signal of PGM decreased. The difference in signals from the PGM before and after addition of histidine has a good linear correlation with the logarithm of the histidine concentrations in the range of 0.01~100 μM with a detection limit of 3.4 nM, which is lower than those of many other chemical sensors. Moreover, the assay of histidine in milk samples is demonstrated with satisfactory results.

A label-free G-quadruplex-based luminescent switch-on assay for the selective detection of histidine

A label-free G-quadruplex-based luminescent switch-on assay has been developed for the selective detection of micromolar histidine in aqueous solution. In this study, an iridium(III) complex was employed as a G-quadruplex-specific luminescent probe while a guanine-rich oligonucleotide (Pu27, 5'-TG4AG3TG4AG3TG4A2G2-3')/cupric ion (Cu(2+)) ensemble was employed as a recognition unit for histidine. The initial luminescence of the iridium(III) complex in the presence of G-quadruplex DNA is effectively quenched by Cu(2+) ions due to the Cu(2+)-mediated unfolding of the G-quadruplex motif. The addition of histidine sequesters Cu(2+) ions from the ensemble, thereby restoring the luminescence of the system. The assay could detect down to 1 μM of histidine in aqueous media, and also exhibited good selectivity for histidine over other amino acids with the use of the cysteine, masking agent N-ethylmaleimide. Furthermore, the application of the assay for the detection of histidine in diluted urine samples was demonstrated.

Electrochemical Aptasensor for L-Histidine Detection via Self-Cleavage of DNAzymes and Amplification of End-Truncated Elongated Tetrahexaheral Gold Nanocrystals

A sensitive aptamer-based signal-on sensor for real-time detection of L-histidine via self-cleavage of DNAzymes and amplification of elongated tetrahexaheral gold nanocrystals (end-truncated-ETHH-Au-NCs) is presented. The introduction of target L-histidine induced self-cleavage of DNAzymes on the end-truncated-ETHH-Au-NCs modified glassy carbon electrode (GCE) into the solution. The resulting change in electron transfer efficiency is readily measured by square wave voltammetry (SWV) at target L-histidine concentrations as low as 0.1 pM, the increase in the SWV peak current is linear with the concentration of L-histidine in the range from 0.1 pM to 0.1 μM. The fabricated aptasensor shows a high specificity for L-histidine which is not affected by the coexistence of other amino acids, and an excellent enantio-selectivity toward L-histidine was achieved.

Electrochemical sensing of L-histidine based on structure-switching DNAzymes and gold nanoparticle-graphene nanosheet composites

A sensitive aptasensor for detection of L-histidine based on the switching structure of aptamer and gold nanoparticles-graphene nanosheets (GNPs-GNSs) composite was reported for the first time. The fabricated biosensor shows an expanded linear range, excellent sensitivity and selectivity against other amino acids.

A study of quenching and enhancing effects of some amino acids on peroxyoxalate chemiluminescence of rhodamine 6G

The quenching effect of l-cysteine, l-methionine on strong chemiluminescence of bis(2,4,6-trichlorophenyl)oxalate-H(2)O(2) system in the presence of rhodamine 6G was studied. The chemiluminescence parameters were evaluated from computer fitting of the resulting intensity-time plots. These systems resulted in Stern-Volmer plots in the quencher concentration range of 4.0 x 10(-6) to 4.0 x 10(-5)M, with K(Q) values of 1.64 x 10(4) and 8.0 x 10(4)M(-1) for l-metionine and l-cysteine, respectively. Also, this study describes the employment of l-histidine as a highly potent signal enhancer in peroxyoxalate chemiluminescence in the presence of rhodamine 6G.

The effects on plasma, red cell and platelet fatty acids of taking 12 g/day of ethyl-eicosapentaenoate for 16 months: dihomogammalinolenic, arachidonic and docosahexaenoic acids and relevance to Inuit metabolism

A patient with mantle cell lymphoma took 12g/day of ethyl-eicosapentaenoate for 16 months. Compared to reference values, eicosapentaenoic and docosapentaenoic acids were elevated in plasma, red cells and platelets but docosahexaenoic acid levels were in the normal range. Arachidonic acid levels were moderately reduced but dihomogammalinolenic acid levels remained in the normal range. In spite of a long chain n-3 fatty acid intake higher than in most Inuit populations, arachidonic acid levels remained considerably higher in this patient than in the Inuit. The implications for understanding of fatty acid metabolism in humans are discussed.

Sudden infant death syndrome Part 2: the response of the reticuloendothelial system to hypoxemia and infection

The incidence of ascites in chicks raised in a high-altitude chamber doubled from 6500 feet to 8000 feet. A similar condition developed in calves transported to pasture at high altitude. Chicks raised in a high-altitude chamber (compared to controls) produced more plasma cells in the germinal centres of the spleen about four days after an antigen challenge. Children usually suffering from a mild respiratory infection at sea level often developed pulmonary edema (HAPE) on transfer to high altitude. Sudden infant death syndrome (SIDS) victims produced more plasma cells in the germinal centers of the spleen. In one survey of SIDS, about half of the infants suffered an upper respiratory tract infection in the two weeks prior to death and the lungs were filled with fluid at autopsy. Elevated levels of hypoxanthine indicated hypoxemia before death, and a presumed response to hypoxemia in SIDS was the presence of extramedullary hematopoiesis in the liver. The effect of prolonged hypoxemia and infection are additive in increasing vascular permeability and the accumulation of edema fluid. The preferential uptake of zinc by edema fluid proteins at the expense of inflammatory cells increases the motility and metabolism of zinc-deprived activated macrophages. Activated macrophages release cytokines which in turn stimulate the release of pro-inflammatory peptides which increase vascular permeability and mortality. These inflammatory peptides are under proteolytic control. The neutral endopeptidase (NEP) is a cell-surface zinc metalloproteinase which modulates toxic shock.Zinc also modulates the inflammatory response of the activated macrophage. Interleukin-12 (IL-12), predominantly a product of macrophages, is involved in regulating both hematopoiesis and the adaptive immune response. IL-12 promotes interferon gamma (IFNgamma) production by T cells. IFNgamma acts on macrophages to release large amounts of nitric oxide (NO). An elevated immune response leads to NO overload, dilation of the cardiovascular system and toxic shock. A mechanism resulting in cardiovascular failure and a shock-like sequence is described in some cases of SIDS.Bradycardia, recorded on cardiorespiratory monitors in six SIDS infants, was considered a late event. Cytokines regulate all aspects of the immune response. Extramedullary hematopoiesis in the liver was one anatomical marker of hypoxemia in SIDS. This survey traces the function of the activated macrophage with the cytokines regulating extramedullary hematopoiesis and the precocious immune response in SIDS.

Sudden infant death syndrome (SIDS): T-cell immunodeficiency--Part 1

It is hypothesized that SIDS mimics AIDS and atopic eczema in that defective T lymphocytes and overactive B cells overstimulate pro-inflammatory cytokines in the mucosal immune system. Virally infected cells are unable to convert linoleic acid (LA) into gamma-linolenic acid (GLA) which eventually leads to defective T lymphocyte production. Abnormal lung cytokine synthesis by virus-induced immunodeficient T lymphocytes is associated with the murine AIDS-related complex (ARC). Adenosine triphosphate (ATP) deficient anaerobic cells cannot convert LA to GLA. It is hypothesized that, in SIDS victims, elevated levels of hypoxanthine and immunoglobulins are evidence of chronic hypoxemia and ATP catabolism, and an inability to convert LA to GLA, leading to defective T lymphocytes in the mucosal immune system.

Treatment pearls from Europe

Discussing the need for psychological treatment of a dermatological condition with children and families can be a daunting task. Families must be given accurate information about the role of psychological or behavioral factors in the exacerbation or maintenance of their child's condition; however, this information must be presented in a way that families and children do not feel criticized or judged. This article discusses nondrug treatments of skin diseases.

Natural micronutrients as controlling factors in Western diseases--a lesson in nature-programming

Micronutrients, essential for approximately 65% of all known enzymes, have during this century been considerably reduced in modern Western diets, due to food refinement, canning, refrigeration and additives. This reduction coincided with a phenomenal increase of Western and industrial diseases, many of them with genetic associations. Different basic diets in genetic races over thousands of years have led to a high percentage of enzyme polymorphisms, suggesting different basic diets necessary for different genetic races. These basic diets, with or without micronutrient supplementation, should be a necessary component of Western diseases prevention and therapy.

Metabolic disorders of cattle

Goldberger discovered human pellagra was a non-infectious disease, affecting mostly the small and the timid in overcrowded institutions. Symptoms were diarrhoea, dermatitis and dementia. The staff and older children escaped the disease. They ate the meat and left the small and timid with the gravy. The 'Goldberger syndrome' is observed during competitive feeding of livestock, in ketotic animals and in the zinc depleted which are lethargic and pick all day at their feed. The pellagra preventative factor was later found to be nicotinic acid, derived from the amino acid tryptophan. Deficiencies of copper, magnesium, vitamin B6 (activated by a zinc kinase) inhibit the conversion of tryptophan to nicotinic acid. Stresses, including liver diseases, malabsorption, iron overload, porphyria, marasmus, cold stress, pregnancy, lactation, antibiotics and sulfa drugs, all increase dietary needs of nicotinic acid. Elevated free fatty acids and ketone bodies in the blood are associated with ketosis, zinc depletion and the pre-diabetic state. There is a diminished uptake of glucose by the tissues, a condition also found in parturient paresis of dairy cows when elevated hydrocortisone promotes insulin resistance and hyperglycaemia. This defect in insulin response leads to a diabetic-like state. The major predisposing factor in parturient paresis of dairy cows is hypocalcaemia. Gut absorption of dietary calcium may not meet the primary demands of lactation initiation until bone calcium mobilisation is established.

The relationship between schizophrenia and essential fatty acid and eicosanoid metabolism

Essential fatty acids (EFAs) and their eicosanoid derivatives are important constituents of the brain and regulators of neuronal function. There is direct and indirect evidence of impaired metabolism of prostaglandin (PG)E1 in schizophrenia. There is also direct evidence of abnormal EFA biochemistry with plasma phospholipids from five populations and brain phospholipids from another all showing reduced levels of linoleic acid and elevated levels of 22-carbon EFAs of both n-6 and n-3 series. Clinical trials of PGE1 and of the PGE1 precursors, gamma-linolenic acid (GLA) and dihomo-gamma-linolenic acid (DGLA) have shown modest therapeutic effects. In view of lack of therapeutic process involving drugs based on the dopamine concept of schizophrenia, it is time for new approaches based on the EFA/PG concept to be evaluated thoroughly.

Is the origin of atopy linked to deficient conversion of omega-6-fatty acids to prostaglandin E1?

Our hypothesis on the origin of atopy links alterations in omega-6-fatty acid metabolism in atopic persons (i.e., reduced formation of delta-6-desaturase products) to deficient T cell differentiation and function. We suggest that a relative deficiency in dihomo-gamma-linolenic acid-derived prostaglandin E1 is the major etiologic factor for diminished T cell maturation postpartum. Its precursors, gamma-linolenic acid and dihomo-gamma-linolenic acid, are physiologically provided in colostrum and mature breast milk of healthy mothers. Depressed cell-mediated immunity and uncontrolled B-cell response with increased IgE synthesis are explained as prostaglandin E1-dependent defects of T cell differentiation caused by insufficient supply of prostaglandin E1 precursors during early infancy. Thus, in our opinion atopy is a metabolic disorder and the associated immunologic disturbances are epiphenomena.

Essential fatty acids in clinical dermatology

A deficiency of essential fatty acid intake can produce severe cutaneous abnormalities but is exceedingly rare in clinical practice. Recent research has shown that abnormalities in essential fatty acid metabolism may play a role in atopic eczema, acne, and psoriasis. Therapeutic innovations have already resulted from this knowledge, and more are likely to emerge.

Prostaglandin E1: a review

Work on the structure of prostaglandin E1 (PGE1), isolated from natural sources, was completed 25 years ago (1). Shortly after, methods for the chemical synthesis of PG with their natural configuration were developed in the laboratories of the UpJohn Company (2) and of E. J. Corey (3) and, by the late sixties, PGE1 became widely available. The information since accumulated about its biological and clinical effects is more substantial than for any other PG. This review will draw together some of this information, focusing on recent studies of its mechanisms of action.

Alteration of mercuric chloride-induced autoimmune glomerulonephritis in brown-Norway rats by herring oil, evening primrose oil and OKY-046 a selective TXA-synthetase inhibitor

Repeated subcutaneous (SC) injections of mercuric chloride (MC) in Brown Norway (BN) rats induce an autoimmune glomerulonephritis (GN) due to antiglomerular basement membrane (BM) antibody deposition in the glomeruli. The aim of this study was to investigate the effects on MC-induced autoimmune GN of OKY-046, a selective TXA-synthetase inhibitor herring oil (HO), which is rich in eicosapentaenoic acid (EPA) (5.6%) precursor of the three series of prostaglandins (PGs) and of (inactive) thromboxane (TXA3), and evening primrose oil (EPO), which is rich in linoleic acid (LA) (72%) and gamma-linolenic acid (GLNA) (9%), precursors of the one series of PGs, mainly PGE1, and of (inactive) TXA1. The administration of OKY-046 significantly inhibited proteinuria, partially prevented fibrin thrombi (FT) formation in the glomeruli, decreased urinary TXB, enhanced 6ketoPGF excretion and, increased survival rate of the animals from 60% (group receiving only MC) to 86%. However, OKY-046 did not prevent body weight (BW) loss or the development and deposition of IgG in the glomeruli. Increased intake of HO (80 days prior and throughout the experiment) and avoidance of arachidonic acid (AA) intake produced an effect comparable to that of OKY-046 in the rats. Furthermore, HO significantly inhibited the deposition of IgG in the glomeruli, increased the survival rate of the animals to 100% and further enhanced the increased urinary PGE excretion induced by MC. However, HO did not prevent BW loss in the animals. Increased intake of EPO and avoidance of AA intake produced an effect comparable to that of HO. Additionally, EPO completely prevented BW loss induced by MC in these animals. These findings suggest that the metabolites of AA, EPA and GLNA play an important role either in the development or in the modulation of this model of MC induced GN.

Homologous physiological effects of nutritional antioxidants and eicosapentaenoic acid

Dietary fish oils rich in eicosapentaenoic acid (EPA) possess immunostimulant, anti-inflammatory, cancer-retardant, antithrombotic and ischemia-protective properties that are remarkably parallel to the effects of high-dose nutritional antioxidants. EPA and nutritional antioxidants may show complementary activities in a wide range of preventive and therapeutic applications.

A deficiency in dietary gamma-linolenic and/or eicosapentaenoic acids may determine individual susceptibility to AIDS

We hypothesize that a relative deficiency in gamma-linolenic and eicosapentaenoic acids and in their derivatives may contribute to the development of AIDS. These polyunsaturated fatty acids (PUFAs) may be the source of natural endogenous agents against AIDS by preventing the spread of viral infection due to their ability to destroy enveloped viruses, by controlling cancer development either directly due to their cytostatic and cytotoxic effects on cancer cells or indirectly by modulating the immune response and by protecting from genetic damage. Supplementation of these dietary PUFAs in the prevention, and possibly in the treatment of AIDS, is considered.

Effect of supplemental vitamin E on the immune system of calves

The effect of vitamin E on immune responses of Holstein calves was investigated. Treatments were: 0,1400, and 2800 mg of dl-alpha-tocopheryl acetate given orally at weekly intervals or 1400 mg of dl-alpha-tocopherol weekly by injection. Calves were fed milk for 6 wk and then fed a complete calf starter ad libitum. Calves were on experiment until they were 12 wk of age. Lymphocyte stimulation indices were significantly higher for calves given the high amount of oral supplementation and for injected calves than for unsupplemented calves. There were no significant differences at any of the individual weeks between unsupplemented and orally supplemented calves. Injected calves showed significantly higher values than unsupplemented calves at wk 4 and than all other calves at wk 8. There were no significant differences in the concentrations of immunoglobulins G1 and G2 among treatments. Immunoglobulin M was significantly higher at wk 6 in calves given the high amount of oral supplementation than in all other calves. At wk 12, serum from calves given the high amount of oral supplementation and calves given injections inhibited infectious bovine rhinotracheitis viral replication in tissue cultures as compared with those of unsupplemented calves. In supplemental experiments serum alpha-tocopherol and lymphocyte stimulation indices of yearling heifers determined 7 d after a single injection of 2000 IU of dl-alpha-tocopherol were significantly higher than preinjection values. In vitro addition of vitamin E to lymphocyte cultures did not increase phytohemagglutinin-induced blastogenesis.

Chronic arachidonic acid eicosanoid imbalance: a common feature in coronary artery disease, hypercholesterolemia, cancer and other important diseases. Significance of desaturase enzyme inhibition and of the arachidonic acid desaturase-independent pathway

A chronic imbalance between the essential fatty acid metabolites arachidonic acid, gamma-linolenic acid and eicosapentaenoic acid and of their respective eicosanoid derivatives appears to be implicated in the etiology of many intractable disease. Most notable among these are coronary artery disease, cancer and chronic inflammation. The factors leading to such an imbalance and their relatively simple prophylactic and therapeutic circumvention are discussed briefly.

Effects of specific nutrients on the immune response. Selected clinical applications

The importance of diet in multiple aspects of the immune response is inescapable. Although only a few trials have attempted to apply knowledge derived from in-vitro and animal data to humans, the ability to modulate or "reset" the immune response by manipulating dietary intake will surely continue to be studied in the future. The role of various nutrients in immunity is reviewed and clinical applications are noted.

A general strategy for the use of allogeneic lymphocyte infusions in the treatment of disorders characterized by impaired helper or suppressor T cell function: autoimmune diseases and the acquired immunodeficiency syndrome (AIDS)

Allogeneic lymphocytes can exert very potent non-specific immunomodulatory effects both in vitro and in vivo. Repeated infusions of allogeneic suppressor or helper populations may find use in the treatment of diseases characterized by impaired suppressor function (such as many autoimmune diseases) or impaired helper function (such as AIDS), respectively. Nutritional adjuvants for use with allogeneic suppressor therapy may include essential fatty acids, zinc, selenium, and vitamin E; the latter two nutrients as well as vitamin C and beta carotene may have value as adjuvants for allogeneic helper therapy. In a small preliminary trial, long-lasting normalization of rheumatoid factor titers and clinical symptoms has been achieved in 5 of 7 cases of chronic rheumatoid arthritis treated with allogeneic lymphocyte infusions, selenium, and vitamin E. These results indicate that allogeneic lymphocyte infusions accompanied by antioxidant support can promote the induction of new appropriate suppressor activity in the host. This phenomenon of allogeneic suppressor induction may be more clinically important than direct allosuppression of host B cells under the conditions of this study, and may find application in the treatment of a number of autoimmune disorders.

Breakdown of P.G.E. 1 synthesis is responsible for the acquired immunodeficiency syndrome

This hypothesis suggests that repeated viral infections disrupt the biosynthesis of P.G.E. 1 and nullify a major system by which t lymphocytes are regulated. It is hypothesized that a breakdown of P.G.E. 1 synthesis is responsible for the acquired immunodeficiency syndrome and the frequently associated Kaposi's sarcoma. A means of restoring P.G.E. 1 synthesis and reversing the immunodeficiency is proposed.

Some varieties of food intolerance in psychiatric patients: an overview

Foods may cause mental and behavioural symptoms by means of a variety of mechanisms. Food allergy is only one of many of these. The paper presents a brief overview of evidence, as of early 1982, concerning cerebral allergy, food addiction, the hypoglycaemias, caffeinism, hypersensitivity to chemical food additives, reactions to vasoactive amines in foods, and reactions attributed to neuropeptides formed from foods as causes of mental symptoms, with particular reference to psychiatric patients. It is concluded that although much work in this field remains to be done, enough is already known to benefit patients now if available knowledge is applied. An individual-centred environmental approach, extending beyond dietary factors if necessary, is recommended as more likely to help than a group-centred paradigm-based approach to treatment.

Essential fatty acid metabolism in diseases of connective tissue with special reference to scleroderma and to Sjogren's syndrome

Drugs which modify the conversion of essential fatty acids to prostaglandins and leukotrienes are the mainstays of treatment in rheumatology. Yet these drugs have little or no action in scleroderma or Sjogren's syndrome and under some circumstances may have adverse effects. Patients with scleroderma have been shown to have very high levels of circulating prostaglandins, coupled with depletion of the prostaglandin precursors, dihomogammalinolenic acid and arachidonic acid. Levels of the metabolites of arachidonic acid, 22:4n-6 and 22:5n-6, which have major roles in maintaining normal cell membrane characteristics were exceptionally low in both plasma and red cell membranes. Others have observed that various functions are highly resistant to normal actions of PGs in scleroderma. This raises the possibility that the high rate of PG formation in scleroderma may be beneficial, in compensation, and that clinical symptoms develop when PG precursors begin to be depleted. Red cell membrane fatty acids patterns in Sjogren's syndrome are almost identical to those in scleroderma. Placebo-controlled trials of supplementation with essential fatty acids have been found to be beneficial in both scleroderma and Sjogren's syndrome.

Melanin: the organizing molecule

The hypothesis is advanced that (neuro)melanin (in conjunction with other pigment molecules such as the isopentenoids) functions as the major organizational molecule in living systems. Melanin is depicted as an organizational "trigger" capable of using established properties such as photon-(electron)-phonon conversions, free radical-redox mechanisms, ion exchange mechanisms, and semiconductive switching capabilities to direct energy to strategic molecular systems and sensitive hierarchies of protein enzyme cascades. Melanin is held capable of regulating a wide range of molecular interactions and metabolic processes primarily through its effective control of diverse covalent modifications. To support the hypothesis, established and proposed properties of melanin are reviewed (including the possibility that (neuro)melanin is capable of self-synthesis). Two "melanocentric systems"--key molecular systems in which melanin plays a central if not controlling role--are examined: 1) the melanin-purine-pteridine (covalent modification) system and 2) the APUD (or diffuse neuroendocrine) system. Melanin's role in embryological organization and tissue repair/regeneration via sustained or direct current is considered in addition to its possible control of the major homeostatic regulatory systems--autonomic, neuroendocrine, and immunological.

Schizophrenia: the role of abnormal essential fatty acid and prostaglandin metabolism

There are two series of essential fatty acids (EFAs), the n6 series starting with linoleic acid and the n3 series starting with alpha-linolenic acid. Members of both series are important in brain structure and can act as precursors for prostaglandin formation. Normally the desaturase enzymes which metabolize EFAs have a higher affinity for the n3 series. It is proposed that in schizophrenia mutant desaturases are present which prefer the n6 series. This change would account for the low levels of linoleic acid, dihomogammalinolenic acid and 1 series prostaglandins which have been reported in schizophrenia. It would also explain the high levels of arachidonic and alpha-linolenic acids and the recently described therapeutic response to alpha-linolenic acid. The abnormal pattern in n6 series EFAs in schizophrenics can almost exactly be imitated in rats by depriving them of n3 EFAs. This is the nearest experimental equivalent to an inability to metabolize EFAs because of an enzyme defect. Heterozygotes carrying such a mutant gene would have an advantage over either form of homozygote since they would be better able to cope with variations in dietary intake of n3 and n6 EFAs.

Reduced levels of prostaglandin precursors in the blood of atopic patients: defective delta-6-desaturase function as a biochemical basis for atopy

In the plasma phospholipids of a group of 50 young adults with atopic eczema, there was an elevation of cis-linoleic acid associated with a deficit of gamma-linolenic acid and of the prostaglandin precursors, dihomogammalinolenic acid and arachidonic acid. This suggests that atopics have a deficit in the function of the delta-6-desaturase enzyme which converts linoleic acid to gamma-linolenic acid. Carriers of cystic fibrosis tend to be phenotypically atopic, supporting previous suggestions that in homozygote cystic fibrosis patients the key defect may be in the delta-6-desaturase enzyme. Atopic patients may be exceptionally sensitive to side effects of non-steroidal anti-inflammatory agents. They fail to flush in response to application of niacin compounds to the skin, a reaction mediated by prostaglandins. A deficit of prostaglandin precursors would explain both of these observations. That the observed biochemical deficit plays a causative role in the manifestations of atopy was indicated by the fact that in a double-blind, placebo-controlled crossover trial, gamma-linolenic acid in the form of evening primrose oil (Efamol), partially corrected both the biochemical abnormalities and the clinical state.

The distribution of ascorbic acid between various cellular components of blood, in normal individuals, and its relation to the plasma concentration

1. A study was undertaken to investigate the distribution of ascorbic acid between various cellular components of blood, in normal individuals, and its relation to the plasma concentration. Forty-one unsupplemented individuals and sixteen supplemented (2 g/d for 5 d) individuals were studied. 2. Granulocytes, mononuclear leucocytes, platelets and erythrocytes were separated by differential sedimentation and centrifugation. Ascorbic acid contents were measured by the dinitrophenylhydrazine method. 3. Ascorbic acid content per cell was higher in mononuclear leucocytes and granulocytes than in platelets and erythrocytes. Intracellular ascorbic acid concentrations, calculated from published values for cell volumes, when compared with the plasma concentration showed a marked ability to concentrate ascorbic acid in mononuclear leucocytes (80 times), platelets (40 times) and granulocytes (25 times). 4. Erythrocytes showed little ability to concentrate ascorbic acid over the normal range of plasma concentration but because of their relative numbers they and the plasma fraction accounted for most of the blood-borne ascorbic acid (greater than 70%). 5. The ascorbic acid content of granulocytes, platelets and erythrocytes showed a significant positive correlation with the plasma concentration and supplementation with ascorbic acid significantly increased the content of these cell types. Mononuclear leucocytes in contrast did not show any such relationship. 6. The ability of the mononuclear leucocytes to maintain the highest levels of ascorbic acid in the cell types studied, despite variation in plasma availability, warrants further study, particularly in view of the importance of these cells in immunocompetence.

Vitamin C and cancer: examination of the Vale of Leven trial results using broad inductive reasoning

Cameron and Pauling have reported large survival increases in terminal cancer patients treated with Vitamin C. Their trials, which have been criticised because not based on random, double-blind principles, are reviewed here using a broad inductive method that relies on diverse data of varying quality. Conclusions are offered both on the value of Vitamin C and on this broad method, as follows: There is a strong possibility that Vitamin C very approximately doubled survival time as measured from the start of Vitamin C treatment, regardless of whether this was after termination of conventional treatment or much earlier. A recent Mayo Clinic trial which concluded that Vitamin C is valueless in the terminal stage may be given an alternative interpretation which supports this view. Despite a speculative element because based only on the condensed, published data, these conclusions have sufficient possibility of validity as to call for full further investigation. The conclusions on method are that the broad, inductive approach may have potential value when the randomized method cannot be used; that it also may facilitate, to the public's benefit, the release of probably valuable, inexpensive, non-toxic treatments pending decisive proof; and a greater return on the research dollar might result from a formal acceptance of the probabilistic element in scientific proof.

Loss of delta-6-desaturase activity as a key factor in aging

Aging is characterized by a wide variety of defects, particularly in the cardiovascular and immune systems. Cyclic AMP levels fall, especially in lymphocytes. Delta-6-desaturase (D6D) levels have been found to fall rapidly in the testes and more slowly in the liver in aging rats. D6D is an enzyme which converts cis-linoleic acid to gamma-linolenic acid (GLA). Other factors which inhibit D6D activity are diabetes, alcohol and radiation, all of which may be associated with accelerated aging. In meat eaters or omnivores which can acquire arachidonic acid from food, the main consequences of D6D loss will be deficiencies of GLA, dihomogamma-linolenic acid (DGLA) and prostaglandin (PG) E1. PGE1 activates T lymphocytes, inhibits smooth muscle proliferation and thrombosis, is important in gonadal function and raises cyclic AMP levels in many tissues. It is a good candidate for a key factor lost in aging. Moderate food restriction, the only manoeuvre which consistently slows aging in homoiotherms, raises D6D activity by 300%. Other factors important in regulating D6D and the conversion of GLA to PGE1 are zinc, pyridoxine, ascorbic acid, the pineal hormone, melatonin, and possibly vitamin B3. GLA administration to humans has been found to lower blood pressure and cholesterol, and to cause clinical improvement in patients with Sjogren's syndrome, scleroderma and alcoholism. These diseases are associated with some features of accelerated aging. The proposition that D6D loss is not only a marker of aging but a cause of some of its major manifestations is amenable to experimental test even in humans. The blocked enzyme can be by-passed by giving GLA directly.

A lack of essential fatty acids as a possible cause of hyperactivity in children

The Hyperactive Children's Support Group (HCSG) in an organisation with over 70 branches in Britain devoted to helping such children and their families. We have carried out a detailed survey of the characteristics of many of our children and their families and have studied the literature in detail. We have come to the conclusion that many of these children have a deficiency of essential fatty acids (EFAs) either because they cannot metabolise linoleic acid normally, or because they cannot absorb EFAs normally from the gut, or because their EFA requirements are higher than normal. The main pieces of evidence are: 1. Most of the food constituents which cause trouble in these children are weak inhibitors of the conversion of EFAs to prostaglandins (PGs). 2. Boys are much more commonly effected than girls and males are known to have much higher requirements for EFAs than females. 3. A high proportion of our children have abnormal thirst and thirst is one of the cardinal signs of EFA deficiency. 4. Many of our children have eczema, allergies and asthma which some reports suggest can be alleviated by EFAs. 5. Many of our children are deficient in zinc which is required for conversion of EFAs to PGs. 6. Some of of our children are badly affected by wheat and milk which are known to give rise to exorphins in the gut which can block conversion of EFAs to PGE1. A preliminary study of EFA supplementation in a number of our children has given promising results. We hope that others with better facilities will be encouraged to test out this hypothesis.

Effects of prostaglandins E1 and E2 on the in vitro production of immunoglobulin by human peripheral blood lymphocytes

The effects of PGE2 and PGE1 on the response of human peripheral blood lymphocytes to Pokeweed mitogen were studied. Addition of PGE2 inhibited IgM production. This effect was augmented by treating the lymphocytes with 2.0 mug/ml of Indomethacin. Addition of PGE1 alone had little effect but augmentation of IgM production was seen in cultures where the lymphocytes had been treated with Indomethacin and PGE1 then added. The results suggest that PGE1/E2 have a small but measurable effect on in vitro IgM production.

The pharmacological role of zinc: evidence from clinical studies on animals

Understanding the roles of zinc in the liver is likely to lead to improved therapy of some clinical conditions. Zinc appears to stimulate protein synthesis in the liver where it increases the binding and inhibits the degradation of insulin. Stimulating or maintaining protein synthesis in the liver is crucial to the outcome of parturition, injury or hepatotoxin challenge. A critical liver protein in circulatory collapse is angiotensinogen. This paper describes the observations of animal responses, in a practical farm situation, to zinc medication.

A new concept of lifestyle-related cardiovascular disease: the importance of interactions between cholesterol, essential fatty acids, prostaglandin E1 and thromboxane A2

A proposal to account for the inter-relationships between established risk factors and cardiovascular disease is presented. In this concept, the critical substance is prostaglandin (PG) E1 which is a vasodilator, an inhibitor of platelet aggregation, an inhibitor of cholesterol and collagen biosynthesis and an inhibitor of smooth muscle proliferation. PGE1 biosynthesis is enhanced by the essential fatty acid, linoleic acid, by the platelet aggregating agent thromboxane (TX) A2, by cholesterol and by melatonin. These factors may participate in a negative feedback control loop. As a result of the operation of this loop, any tendency for PGE1 levels to fall is followed by increased cholesterol and TXA2 biosynthesis, and enhanced platelet aggregation, vasoconstriction, smooth muscle proliferation and collagen biosynthesis. Enhancement of PGE1 biosynthesis will have the opposite effects. Factors known to increase PGE1 biosynthesis include essential fatty acids, vitamin C, ethanol, pyridoxine, zinc and probably niacin, all of which are known to have some protective effects against cardiovascular disease. The hypothesis predicts that lowering of cholesterol biosynthesis by any method other than enhanced PGE1 formation, while reducing the risk of cardiovascular disease, will increase the risk of other disorders. The hypothesis suggest new approaches to treatment and new ways of combining existing treatments. Colchicine, which at low concentrations may imitate and action of melatonin, has particularly interesting possibilities. Colchicine and related compounds have already been shown to have potent cholesterol-lowering and anti-atherogenic actions in both humans and animals.