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Biomedical subjects

P Gold

Publications and source records attributed to P Gold.

At least 37 records · Page 2Linked to original sources
PubMed1991

The biological activity of undenatured dietary whey proteins: role of glutathione.

This study compared the effects of different sources of whey protein concentrate (20 g/100 g diet) and of casein on the spleen, liver, and heart glutathione content of C3H/HeJ mice, and on the immune response of their spleen cells to sheep red blood cells. Body weight curves were similar in all dietary groups. Our data indicate that the humoral immune response is highest in mice fed a dietary whey protein concentrate exhibiting the highest solubility (undenatured conformation) and a greater relative concentration of the thermolabile bovine serum albumin and immunoglobulins. In addition, the mice fed this type of whey protein concentrate exhibit higher levels of tissue glutathione. The presence in the serum albumin fraction of glutamylcysteine groups (rare in food protein) and the specific intramolecular bond as related to the undenatured conformation of the molecule are considered to be key factors in the glutathione-promoting activity of the protein mixture.

Animals↗
PubMed1990

Medical grand rounds: alive and well and living in Canada.

Grand rounds have long been the principal educational activity of departments of medicine at teaching hospitals. Several recent articles have suggested that there has been a general deterioration in the quality of grand rounds. To evaluate their status in Canada we mailed a questionnaire to the chairmen of the departments of medicine at the 53 Canadian teaching hospitals; of the 48 responses received (91%), 38 were from chairmen, 5 were from senior department members, and 5 were from chief residents. The results indicated that grand rounds continued to be the principal teaching exercise of the departments. Of the respondents 98% felt that the quality had improved or stayed the same. The overall attendance was considered to have improved or remained unchanged for the past decade by 75%; 25% thought that it had declined. The diminished emphasis on patient-related topics concerned 10%. The respondents gave numerous suggestions, which should help organizers to improve the impact of grand rounds on learning.

Canada↗
PubMed1990

Cerebrospinal fluid levels of somatostatin, corticotropin-releasing hormone and corticotropin in alcoholism.

Reduced brain and cerebrospinal fluid (CSF) levels of somatostatin, corticotropin-releasing hormone (CRH) and corticotropin (ACTH) have been reported among neuropsychiatric patients with cognitive dysfunction. Alcoholism is a disorder in which associated neuropsychiatric disorders occur. Therefore, we compared CSF levels of somatostatin, CRH and ACTH in alcoholics (n = 100) and normal controls (n = 30). There were no significant differences between the groups in concentrations of the 3 peptides. Moreover, there were no significant correlations between concentrations of the peptides in CSF and computed tomographic measures of the size of brain ventricles. There were, however, significant correlations between CSF concentrations of CRH and ACTH and between CSF concentrations of CRH and somatostatin in both the alcoholic and control groups.

Adrenocorticotropic Hormone↗
PubMed1990

Dietary milk proteins inhibit the development of dimethylhydrazine-induced malignancy.

This study investigated the influence of two formula diets containing 20 g/100 g diet of either whey protein concentrate or casein, or Purina mouse chow on 1,2-dimethylhydrazine (DMH)-induced colon carcinoma in A/J mice. Four weeks after the 24th DMH treatment the incidence of tumour and tumour area in the whey protein-fed mice was substantially less in comparison to either the casein or Purina groups. The Purina group exhibited the greatest tumour burden. At the end of the experiment all animals continuously fed the whey protein diet were found to be alive, whereas 33% of those on the casein or Purina diet had died. Animals fed Purina diet for 20 weeks and then switched to either milk protein diet for a further 8 weeks exhibited a decrease in tumour burden as compared to those animals fed the Purina diet continuously. Body weights were similar in all dietary groups. In conclusion, a whey protein diet appears to significantly influence the development of chemically induced colon tumours and the short-term survival of mice.

Adenocarcinoma↗
PubMed1989

CSF GABA and neuropeptides in pathological gamblers and normal controls.

We previously reported that pathological gamblers may have increased central noradrenergic activity. Neurons releasing gamma-aminobutyric acid (GABA) are known to be a part of an inhibitory system regulating the activity of central noradrenergic neurons. Therefore, we examined cerebrospinal fluid (CSF) levels of GABA in pathological gamblers and normal controls. There was no significant difference between the groups. Also, depressed and nondepressed gamblers did not differ significantly in their CSF levels of GABA. Among controls, however, there was a significant negative correlation between CSF levels of GABA and the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) and a significant positive correlation between CSF levels of GABA and corticotropin releasing hormone (CRH). Also, CSF levels of CRH showed a significant positive correlation with CSF levels of adrenocorticotropic hormone in both pathological gamblers and controls.

Adult↗
PubMed1989

The assessment of abnormalities in hormonal responsiveness at multiple levels of the hypothalamic-pituitary-adrenocortical axis in depressive illness.

A substantial body of data suggests that excessive cortisol secretion in depression may result from dysregulation at several sites within the hypothalamic-pituitary-adrenocortical (HPA) axis. The alterations in regulatory mechanisms are thought to result from a limbic system-hypothalamic "overdrive" of corticotropin-releasing hormone (CRH). We also have demonstrated that excessive secretion of cortisol may result from an abnormal adrenocortical responsiveness to adrenocorticotropic hormone (ACTH), and we have postulated that corticotropic cells within the pituitary mediate between excessive secretion of CRH from the hypothalamus and hypercortisolemia secondary to adrenocortical hyperplasia and enhanced sensitivity to ACTH at the adrenal cortex. The present report describes a series of clinical experiments utilizing several neuroendocrine probes, as well as computer-assisted tomography, to examine the complexities of the HPA axis dysregulation in depression. These studies support the hypothesis that a limbic system-hypothalamic disturbance results in excessive CRH secretion as well as enhanced adrenocortical activity, and that these factors contribute to excessive cortisol secretion in patients with depression. These data further support the hypothesis that endogenous affective disorders are best characterized in the framework of a generalized biological disturbance of HPA axis function which involves both central and peripheral endocrine sites.

Adrenocorticotropic Hormone↗
PubMed1989

Diazepam-binding inhibitor and corticotropin-releasing hormone in cerebrospinal fluid.

Diazepam-binding inhibitor (DBI) is a neuromodulatory peptide for gamma-aminobutyric acid (GABA) neurotransmission. Cerebrospinal fluid (CSF) levels of DBI have been found to be elevated in depression. CSF levels of the peptide corticotropin-releasing hormone (CRH) have also been found to be elevated in depression. Therefore, we examined for a relationship between DBI and CRH in human CSF. We found significant positive correlations between CSF levels of DBI and CRH in depressed patients, pathological gamblers, and normal controls. These data, along with the elevated CSF levels of DBI in depression, suggest the possibility that DBI may have a role in coordinating responses to stress in humans in addition to its possible role in the pathophysiology of depression.

Adult↗
PubMed1989

The influence of dietary whey protein on tissue glutathione and the diseases of aging.

This study compared the effects of a whey-rich diet (20 g/100 g diet), with that of Purina mouse chow or casein-rich diet (20 g/100 g diet), on the liver and heart glutathione content and on the survival of old male C57BL/6NIA mice. The study was performed during a limited observation period of 6.3 months. In mice fed the whey protein-rich diet between 17 months and 20 months of age, the heart tissue and liver tissue glutathione content were enhanced significantly above the corresponding values of the casein diet-fed and Purina-fed mice. Mice fed the whey protein diet at the onset of senescence at 84 weeks, exhibited increased longevity as compared to mice fed Purina mouse chow over the 6.3 month observation period extending from the age of 21 months (corresponding to a human age of 55 years) to 26-27 months of age (corresponding to a human age of 80 years), during which time 55% mortality was observed. The corresponding mean survival time of mice fed the defined casein diet is almost identical to that of Purina-fed controls. Body weight curves were similar in all three dietary groups. Hence a whey protein diet appears to enhance the liver and heart glutathione concentration in aging mice and to increase longevity over a 6.3 month observation period.

Aging↗
PubMed1989

Immunoenhancing property of dietary whey protein in mice: role of glutathione.

The spleen cells immune response to sheep red blood cells of C3H/HeJ mice fed a 20 g whey protein/100 g diet is substantially higher than that of mice fed an equivalent casein diet of similar nutritional efficiency. The present study indicates that the observed immunoenhancing effect of the whey protein mixture is dependent on the overall amino acid pattern resulting from the contribution of all its protein components. Whey protein contains substantially more cysteine than casein. Dietary cysteine is considered to be a rate limiting substrate for the synthesis of glutathione which is necessary for lymphocyte proliferation. Our studies show that enhancement of host humoral immune response is associated with greater and more sustained production of splenic glutathione during the antigen driven clonal expansion of the lymphocyte in whey protein fed mice in comparison to mice fed the equivalent casein or the cysteine-enriched casein diet. Hence the efficiency of dietary cysteine in inducing supernormal glutathione levels is greater when it is delivered in the whey protein than as free cysteine. Administration of S-(n-butyl) homocysteine sulfoximine, which reduces splenic glutathione level by half, produces a 4-5 fold drop in the humoral immune response of whey protein diet-fed mice. This is further evidence of the important role of glutathione in the immunoenhancing effect of dietary whey protein.

Animals↗
PubMed1988

The CRH stimulation test in bereaved subjects with and without accompanying depression.

We studied recently bereaved individuals with the corticotropin-releasing hormone (CRH) stimulation test. Subjects with a bereavement complicated by a depressive illness (n = 9) had significantly higher basal plasma cortisol levels and smaller plasma adrenocorticotropic hormone (ACTH) responses to CRH than either subjects with an uncomplicated bereavement (n = 19) or normal controls (n = 34). Subjects with depressed bereavement showed ACTH responses to CRH similar to those of depressed patients (n = 30). Bereaved subjects who had received psychotropic medications in the past (n = 13), compared with those who had not (n = 15), showed significantly smaller plasma ACTH responses to CRH. Significantly more subjects with bereavement complicated by depression, as compared to subjects whose bereavement was uncomplicated, had a past history of treatment for depression. These results suggest that predisposed individuals may respond to the stress of bereavement with a depressive illness accompanied by dysregulation of the hypothalamic-pituitary-adrenal axis.

Adjustment Disorders↗
PubMed1988

Evolutionary traits in human milk proteins.

Human milk has the lowest concentration of protein of any mammalian species. Since the rate of growth of the offspring is negatively related to the protein content of the milk, the time required to double the birth weight is greater in the infant than in any other mammal in which it has been measured. Similarly, in weaned animals, a low protein diet increases the time required to reach maximal growth, senescence and natural death. Human milk protein has the highest whey protein to casein ratio than the milk of any other mammalian species. Our previous experiments have shown that mice fed a 20% whey protein diet exhibit increased resistance to Streptococcus pneumoniae and a humoral immune response significantly higher than that of mice fed most of the commercially available animal and plant proteins in nutritionally similar and adequate formula diets. Other studies have demonstrated that mean and maximal longevity of hamsters fed a 20% whey protein diet is increased in comparison with those fed commercial laboratory feed or a supplemented casein diet of similar nutritional efficiency. Thus, the low protein content and the prevalence of whey protein, which are characteristic features of human milk, are both associated with slow body growth and increased longevity. For human infants, mother's milk is the first and, for most, the only food ingested for a considerable period of time. We, therefore, propose that a trace of Nature's design for the offspring and the evolution of the species can be found in mother's milk.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Clinical applications of carcinoembryonic antigen.

Although carcinoembryonic antigen (CEA) has been the subject of interest for many investigators for over 20 years, many questions still remain unanswered concerning the CEA molecule. These include the ultimate clinical potential of CEA as a tumor marker (specificity, sensitivity, distribution), the biological role of CEA, and the genetic control of CEA synthesis. Initially, much of the work with CEA concerned its physicochemical and immunochemical properties, as well as of cross-reacting molecules, and methods of serologic detection of CEA. More recent studies have focused on cloning of the CEA gene and genetic control of CEA production. An extensive literature exists concerning the role of serum CEA assays and their potential value in determining the prognosis and monitoring of patients affected with cancers of various organs. Despite extensive research into the biology of CEA, few papers deal with the application of CEA immunohistochemistry and immunocytochemistry as concerns normal cellular development, the degree of tumor anaplasia, and the various diagnostic problems of surgical pathology. There has also been a great deal of interest in the utility of both polyclonal and monoclonal antibodies to CEA both in the radioimmunolocalization and potential therapy of CEA-producing tumors. This review summarizes the past and current findings of the clinical applicability of the serum measurement of CEA and examines the status of radioimmunolocalization of tumors as a basis for effective antibody targeted immunotherapy in the future.

Antibodies, Monoclonal↗
PubMed1988

The immunoenhancing property of dietary whey protein concentrate.

The plaque-forming cell response to sheep red blood cells was found to be enhanced in mice fed a formula diet containing 20 g lactalbumin/100 g diet in comparison to mice fed equivalent formula diets of similar nutritional efficiency containing 20 g/100 g diet of either casein, soy, wheat or corn protein, egg albumin, beef or fish protein, Spirulina maxima, or Scenedesmus protein, or Purina mouse chow. This effect was manifest after 2 weeks and persisted for at least 8 weeks of dietary treatment. Mixing lactalbumin with either casein or soy protein in a 20 g protein/100 g diet formula significantly enhanced the immune response in comparison to that of mice fed diets containing 20% soy protein or casein.

Adjuvants, Immunologic↗
PubMed1988

Dietary whey protein inhibits the development of dimethylhydrazine induced malignancy.

This study investigates the influence of two formula diets containing 20 g/100 g diet of either whey protein concentrate or casein or Purina mouse chow, on the humoral immune responsiveness and dimethylhydrazine induced colon carcinogenesis in A/J mice. After 20 weeks of dimethylhydrazine treatment, the number of plaque forming cells per spleen, following intravenous inoculation with 5 X 10(6) sheep red blood cells, was nearly three times greater in the whey protein-fed group than in the casein-fed mice although both values were substantially below normal. After 24 weeks of dimethylhydrazine treatment the incidence of tumors in the whey protein-fed mice was substantially lower than that in mice fed either the casein or Purina diet. Similarly, the tumor area was less in the whey protein group in comparison to either the casein or Purina groups, with some difference between casein and Purina groups. Body weight curves were similar in all dietary groups. In conclusion, a whey protein diet appears to significantly inhibit the incidence and growth of chemically induced colon tumors in mice.

1,2-Dimethylhydrazine↗
PubMed1987

Pituitary and adrenocortical responses to the ovine corticotropin releasing hormone in depressed patients and healthy volunteers.

It has been suggested that limbic system-hypothalamic "overdrive" may be the underlying mechanism causing an augmented secretion of corticotropin releasing hormone (CRH), heightened adrenocortical responsiveness to corticotropin (adrenocorticotropic hormone) (ACTH), and alteration in cortisol feedback regulatory mechanisms as demonstrated by the dexamethasone suppression test. We examined pituitary and adrenocortical responses after morning administration of ovine CRH (oCRH) in 26 depressed patients and 11 healthy volunteers. Basal plasma ACTH concentrations were similar in both groups, whereas patients had a significantly diminished cumulative ACTH response after administration of oCRH. In contrast, basal total cortisol concentrations and cumulative cortisol responses to oCRH were similar in depressed patients and controls. Patients with melancholic features demonstrated the most profound ACTH blunting after oCRH, whereas patients separated according to dexamethasone suppression test results had similar ACTH and cortisol responses to oCRH. The present results extend data from prior studies utilizing oCRH in the evening and demonstrate a dysregulation of the functional integrity of the hypothalamic-pituitary-adrenocortical axis in depressive illness after a morning oCRH test at both central and peripheral hypothalamic-pituitary-adrenocortical axis sites.

Adrenocorticotropic Hormone↗