Showing papers by "Icahn School of Medicine at Mount Sinai published in 1976"
TL;DR: The data of the present study are consistent with a role for the hydroxyl radical and appear to rule out a direct causative role for hydrogen peroxide, while other data rule out any protective role for transiently elevated levels of blood glucose resulting from the administered compounds.
252 citations
TL;DR: The cytosol from livers of adult female mammals contains [3H]estradiol-binding proteins that can translocate to the nucleus and attach to chromatin that may be an estrogen receptor involved in modulating hepatic synthesis of selective plasma proteins.
Abstract: The cytosol from livers of adult female mammals contains [3H]estradiol-binding proteins that can translocate to the nucleus and attach to chromatin. In comparison to the prepubescent rat, adults have higher estrogen binding in the liver and greater increases in plasma renin substrate after administration of estrogen. The protein in the liver which binds estrogen may be an estrogen receptor involved in modulating hepatic synthesis of selective plasma proteins.
206 citations
TL;DR: The results suggest that a vector description is not only a convenient mathematical tool, but is the way eye movements are coded in the PRF and possibly elsewhere in the central nervous system.
171 citations
TL;DR: The results of this study and other studies where low concentrations of hydroxyl radical scavengers stimulate both prostaglandin biosynthesis and lipid peroxidation are consistent with a mechanism involving the hydroxym radical both in the generation of singlet oxygen and the elimination of hydrogen peroxide.
160 citations
TL;DR: In this paper, the minimum contrast between alternate light and dark bars required to distinguish the pattern from a homogeneous field was calculated at each of several spatial frequencies which were established by varying the width of the bars and hence the coarseness of the pattern.
Abstract: Thirty-five patients with known cerebral lesions complained of recently acquired blurred vision. None of them had evident oculomotor or pupillary abnormalities, and each had intact central fields and normal visual acuity by conventional standards. Examination of spatial contrast sensitivity was carried out with sinusoidal grating patterns, by determining the minimum contrast between alternate light and dark bars required to distinguish the pattern from a homogeneous field. This was done at each of several spatial frequencies which were established by varying the width of the bars and hence the coarseness of the pattern. The contrast sensitivities were plotted as "visuograms" which, by analogy to audiograms, record the sensitivities in comparison to normal standards. Of the 35 patients, most showed significant losses, amounting to greater than 50 per cent elevation of contrast thresholds. Eighteen showed high frequency losses; 11 had uniform reductions over the entire visible spatial frequency range and 6 had selective frequency losses in the intermediate frequency ranges. These defects in spatial contrast sensitivity, which were not predictable from standard acuity scores, indicate that the visual symptoms in our patients may have been caused by damage to frequency-selective neural elements in the central visual systems. The method may be used to advantage in clinical investigations as well as in physiological investigations of the functional pathways subserving central vision.
158 citations
TL;DR: Peripheral blood lymphocytes from six patients with congenital hypoplastic anemia suppressed erythroid cell formation by normal human bone marrow cells in response to erythropoietin in vitro, suggesting that the anemia in these children has an immunologic basis.
Abstract: Peripheral blood lymphocytes from six patients with congenital hypoplastic anemia suppressed erythroid cell formation by normal human bone marrow cells in response to erythropoietin in vitro. The results suggest that the anemia in these children has an immunologic basis.
139 citations
TL;DR: With this assay system, it was determined that SOD levels in rat brain, liver, and spinal cord were 84, 660, and 56 μg of SOD/g of tissue, respectively, which agree very well with results obtained by other assays.
136 citations
TL;DR: The analyses showed that the consumer products examined were rarely the pure mineral talc, but rather were mixtures of various minerals; some samples consisted of three to five minerals, only one of which was talc.
Abstract: Representative consumer talcums and powders, including 20 body powders, baby powders, facial talcums, and also one pharmaceutical talc, were analyzed to determine their mineralogical and chemical composition. Where known, all were formulated prior to 1973. Of the 20 products 10 contained detectable amounts of tremolite and anthophyllite, principally asbestiform, while some also contained fragmented forms of these minerals. The amounts ranged from tenths of a percent to over 14% by weight; two contained detectable amounts of chrysotile asbestos fiber. Eight contained quartz, seven ranging from 2 to 5%, with one as high as 35%. The analyses showed that the consumer products examined were rarely the pure mineral talc, but rather were mixtures of various minerals; some samples consisted of three to five minerals, only one of which was talc. Other common mineral phases included chlorite, platy serpentine, pyrophyllite, mica, and carbonate minerals. Kaolin additive was identified in two products. The single pha...
113 citations
108 citations
106 citations
TL;DR: In rats, long-term ethanol ingestion doubled microsomal 5alpha-testosterone reductase activity, a major pathway for testosterone metabolism, while in human volunteers the activity was increased two- to fivefold, which may play a role in the altered androgenic activity of the chronic alcoholic.
Abstract: Male alcoholics often suffer from features of hypogonadism related to abnormal metabolism of sex steroids. Since the activity of testosterone reductases is rate limiting for testosterone metabolism in the liver, the effect of prolonged ethanol consumption by rats and human volunteers on the activities of these microsomal and cytosolic enzymes was studied. In rats, long-term ethanol ingestion doubled microsomal 5alpha-testosterone reductase activity, a major pathway for testosterone metabolism, while in human volunteers the activity was increased two- to fivefold. These changes may play a role in the altered androgenic activity of the chronic alcoholic.
TL;DR: It is concluded that trans-synaptic factors regulate the maturation of adrenergic nerve terminals, and the development of end organ innervation by SCG.
TL;DR: This recognition of the high-risk patient in the perimenopausal years may be aided by aspiration curettage of ambulatory women, for such a strategy of surveillance is practical and efficient.
TL;DR: Chimpanzees chronically infected with hepatitis-B virus showed transient changes in several markers of infection when treated with the interferon inducer polyriboinosinic-polyribocytidylic acid-poly-l-lysine carboxymethyl cellulose, and defective (D.N.A.A.-polymerase-negative) Dane particles increased in titre transiently during treatment; these may play a role in the modulation of hepatitis- B virus infection.
TL;DR: It is to be stressed that the diagnosis of diabetic neuropathy is more than an academic exercise, since each diabetic neuropathic syndrome carries with it some beneficial therapeutic modality to aid the patient.
Abstract: The importance of diabetic neuropathy derives from its remarkable frequency and its clinical impact. In view of the varying underlying pathogenetic mechanisms and the resulting diversity of clinical representations, it becomes apparent that there are diabetic neuropathies, rather than a single entity of diabetic neuropathy. The scope of involvement is widespread with virtually every system at risk. Although peripheral neuropathy is by far the most common expression, visceral neuropathy is also highly significant. It may affect every part of the gastrointestinal tract, the genitourinary tract, and sexual function, as well as direct autonomic nerve pathology. Clearly, neuropathy in diabetes offers a specific and important diagnostic challenge to the clinician and plays a definitive role in differential diagnosis. The problem is heightened by the fact that any and all of the diabetic neuropathic syndromes may be the initial clinical manifestation of diabetes in the absence of covert manifestations of carbohydrate metabolic disorder. It is to be stressed that the diagnosis is more than an academic exercise, since each diabetic neuropathic syndrome carries with it some beneficial therapeutic modality to aid the patient.
TL;DR: The proportion of choline converted to acetylcholine in synaptosomes previously depolarized is the same as those incubated in normal K + Krebs Ringer; thus the absolute rate of acetyl choline synthesis in nerve terminals is increased as a result of prior depolarization.
TL;DR: The plasma ratio of alpha-amino-n-butyric acid to leucine was elevated in ambulatory and hospitalized alcoholics as well as in baboons fed alcohol along with an adequate diet.
Abstract: The plasma ratio of alpha-amino-n-butyric acid to leucine was elevated in ambulatory and hospitalized alcoholics as well as in baboons fed alcohol along with an adequate diet. There was a statistically significant positive correlation between this ratio and the degree of alcoholism assessed by three separate medical and psychological criteria in patients maintained on methadone.
TL;DR: The E 2 R and E 2 DH levels observed in patients with endometrial cancer can be explained on the basis of the hormonal environment of the tissue at the time of sampling without postulating drastically altered binding and metabolism of E 2 in abnormal endometrium.
TL;DR: An evaluation of results obtained in 438 thymectomies of which 233 were via the transcervical approach and an analysis of factors related to immunity influencing the response to thymectomy and risk of oncogenesis are obtained.
Abstract: Application of thymectomy in the treatment of myasthenia gravis was based originally on empirical observations. Similarly, indications for thymectomy were developed empirically from preliminary results reported by Keynes 2* and Harvey.4 Lack of knowledge of the etiology of myasthenia gravis and of the function of the thymus gland, and the small numbers of selected patients in most of the early series resulted in conflicting reports 5-7 on the role and value of thymectomy in myasthenia gravis. In recent years there has been a rapid expansion of knowledge concerning the thymus gland 8, 9 and its relationship to immune surveillance.10 The reports of the immunologic effects of neonatal thymectomy l1 were followed by the observations that adult experimental thymectomy has also delayed immunologic effects.lZ3 l3 Thymectomy was originally thought to result in an increase of the risk of oncogenesis, but as Allison pointed out in 1967 certain neoplasms decrease following thymectomy.14 Decrease in the risk of oncogenesis following thymectomy in patients with myasthenia gravis has been previously r e ~ 0 r t e d . l ~ Accumulating evidence that autoimmunity may play a major role in the pathophysiology of myasthenia gravis,l6V l7 the possibility that liability to autoimmunity might be a thymus-dependent state,’R and the experience with a large number of patients who have undergone the simplified transcervical thymectomy l9 permit a reevaluation of the role of thymectomy in myasthenia gravis. The present report is an evaluation of results obtained in 438 thymectomies of which 233 were via the transcervical approach and an analysis of factors related to immunity influencing the response to thymectomy and risk of oncogenesis. Results of thymectomy and risk of oncogenesis were correlated with thymic pathology, electromyographic findings, age, preoperative duration of disease, peripheral lymphocytes, 17-ketosteroid excretion, and carcinoembryonic antigen (CEA) titers.
TL;DR: It has not been established that homosexual men are characterized by abnormalities in plasma testosterone, and current pharmacological research does not furnish specific evidence, that the administration of androgens or preparations that stimulate the secretion of endogenous androgens have beneficial effects on functional impotence.
Abstract: The scope of this article will be a review and brief discussion of recently gathered information on androgens and sexual behavior in men. It will include experimental observations on the covariance between androgens, mainly testosterone, and sexual functioning in normal heterosexual men and studies on sexual dysfunction and homosexual behavior. The effects of castration, hypogonadal conditions, hormonal replacement, and endogenous testosterone variations on sexual behavior are examined. Further psychoendocrine studies, are necessary to evaluate the role of gonadal hormone production in impotency. Current pharmacological research does not furnish specific evidence, that the administration of androgens or preparations that stimulate the secretion of endogenous androgens have beneficial effects on functional impotence. After reviewing the studies on male homosexuality and androgen levels, the article concludes that it has not been established that homosexual men are characterized by abnormalities in...
TL;DR: It is shown that chronic lead exposure results in significant hematopoietic inhibition of the heme biosynthetic pathway without causing significant changes in hepatic cytochrome P‐450‐associated enzymic activities.
Abstract: Acute administration of lead to rats caused significant decreases in cytochrome P=450, ethylmorphine N-demethylase, and aniline hydroxylase activities and prolonged hexobarbital-induced sleeping times. However, chronic administration of lead to weanling rats caused no significant changes in hepatic cytochrome P-450 levels or in the microsomal oxidative enzymes over a 12-wk period. Eight patients exposed to lead in the process of burning through lead-painted steel structures for at least 3 mo showed marked effects of chronic lead intoxication on the erythropoietic system: inhibition of erythrocyte delta-aminolevulinic acid dehydratase, increased erythrocyte protoporphyrin levels, and increased urinary excretion of delta-aminolevulinic acid. Chelation therapy greatly alleviated the inhibitory effects on dehydratase activity and decreased urinary delta-aminolevulinic acid excretion. The plasma elimination rate of antipyrine, a drug primarily metabolized by hepatic microsomal enzymes, was determined in the 8 subjects prior to and following chelation therapy. In 7 of 8 subjects, chelation therapy shortened the antipyrine half-lives, but the effect was minimal. These studies show that chronic lead exposure results in significant hematopoietic inhibition of the heme biosynthetic pathway without causing significant changes in hepatic cytochrome P-450-associated enzymic activities.
TL;DR: The results suggest that pituitary ACTH secretion in some patients with Nelson's Syndrome is under Central Nervous System control.
Abstract: Cyproheptadine (24 mg q.d.) was administered to four patients with Nelson's Syndrome for a 3-5 month period. This resulted in a significant reduction in plasma ACTH and prolactin concentrations in 3 of these subjects. A rise in plasma ACTH concentrations occurred following discontinuance of medication in one patient. The results suggest that pituitary ACTH secretion in some patients with Nelson's Syndrome is under Central Nervous System control.
TL;DR: Thiols containing free amino and free sulfhydryl groups in close proximity were the most effective in relieving the inhibition by acetaldehyde and cysteine did not significantly prevent the inhibition of oxidative phosphorylation by acetalde, however, the mitochondria remained coupled in the presence of acetaldehyde plus cysteines.
TL;DR: Although dynamically related to N.T.R., Freud had already anticipated delineating this mechanism by 1916 when he uncovered the meaning of certain manifestations occurring outside the treatment situation: criminals from a sense of guilt, those wrecked by success, fate neuroses, etc.
Abstract: N CLINICAL EXPERIENCE ONE OCCASIONALLY encounters the I frustration of an analysis that fails to progress despite correct interpretive work. Equally perplexing is the paradoxical increase in symptoms that may follow a correct interpretation. Freud first characterized these phenomena as negative therapeutic reactions in “The Ego and the Id” (1923). Originally considering it a response to a “moral factor, a sense of guilt, which is finding its satisfaction in the illness and refuses to give up the punishment of suffering’’ (p. 49), the following year he modified the concept to “a need for punishment” (1924, p. 166). In his formulation, this need was rooted in oedipal guilt, the analytic counterpart of original sin, which had similarly motivated generations of Christian martyrs to seek punishment. Freud had already anticipated delineating this mechanism by 1916 when he uncovered the meaning of certain manifestations occurring outside the treatment situation: criminals from a sense of guilt, those wrecked by success, fate neuroses, etc. I ‘ . . . it is the forces of conscience which forbid’ the subject to gain the long hoped-for advantage from the fortunate change in reality” (1916, p. 318). Although dynamically related to N.T.R., these will be omitted from the present discus-
TL;DR: In fasted rats, single injection of pentagastrin (250 mug/kg) stimulates epithelial cell proliferation in the duodenum and colon, but not in the esophagus, and fasting for 64 hours suppresses cell proliferation more markedly in colonic crypts than in duodenal crypts, and pentagastsrin restores the cell proliferative activity of the colon andduodenum to levels comparable with those of fed rats.
TL;DR: Data from three patients who recovered from cerebral blindness suggest that structures of the central nervous system which determine evoked potentials and psychophysical responses to high frequency gratings are either identical or similarly vulnerable and suggest why mid- and high-spatial frequency channels of the primary visual pathways may be especially vulnerable to cerebral lesions.
Abstract: QUANTITATIVE studies of vision in patients with cerebral lesions pose a challenge to purely topographical concepts of cerebral organisation. Pyschophysical measurements of the detectability of sinusoidal gratings (contrast sensitivity functions)1 established that in the majority of patients detection of high spatial frequencies suffers most. The spatial frequency of a grating is the number of its alternating bars subtended in 1° of visual angle; the higher the number, the finer the pattern. There seems to be no obvious correlation between this loss of fine pattern discrimination and the aetiology or the exact localisation of a cerebral lesion. The neural basis of this loss is unknown in vision as with the other senses. Is it the result of specific vulnerability of those neurones of the primary visual pathways which are optimally responding to high spatial frequencies or to some defect of high order cognitive functions? In this report I present data on three patients who recovered from cerebral blindness. Serial evoked potentials and psychophysical detection of gratings of high frequency showed concurrent changes throughout recovery in one patient in whom they could be measured. This suggests that structures of the central nervous system which determine evoked potentials and psychophysical responses to high frequency gratings are either identical or similarly vulnerable. These data also suggest why mid- and high-spatial frequency channels of the primary visual pathways may be especially vulnerable to cerebral lesions.
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01 Nov 1976TL;DR: Analysis of the error distributions indicated that patients with inferred right hemisphere damage and those with inferred bilateral damage tended to make significantly more bilateral errors than the normals.