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Keith D. Smith

Bio: Keith D. Smith is an academic researcher from Albert Einstein Medical Center. The author has contributed to research in topics: Testosterone (patch) & Testosterone. The author has an hindex of 17, co-authored 25 publications receiving 1136 citations.

Papers
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TL;DR: Plasma testosterone level and testosterone production rate were determined in a group of 18 healthy young men, 15 healthy older men and 6 hospitalized dysphoric male patients and age was the principal correlant of production rate in the older group.
Abstract: &NA; Plasma testosterone level and testosterone production rate were determined in a group of 18 healthy young men, 15 healthy older men and 6 hospitalized dysphoric male patients. A battery of anxiety, depression and hostility tests were administered simultaneously. Production rate of testosterone was found to be highly correlated with a measure of aggression derived from the Buss‐Durkee Hostility Inventory in the younger men. Age, on the other hand, was the principal correlant of production rate in the older group. A multivariate regression equation was obtained between testosterone production rate and four psychologic measures of aggression and hostility which accounted for 82% of the variance in the production rate of testosterone for the younger group. This equation was not valid for the older men.

203 citations

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TL;DR: The presented recommendations may not be appropriate in all situations and any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances.

189 citations

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TL;DR: Correlation of data with plasma androgen levels from this patient's peripheral and spermatic veins led the authors to conclude that, as in lower species, high local levels of androgen will initiate spermatogenesis in man.
Abstract: Morphologic and steroid biochemical studies were performed on surgical specimens from a 6-yr-old boy with a Leydig cell tumor. Active spermatogenesis to early spermatid stage was found in the testicular tissue of the tumorbearing testis, and absence of spermatogenesis was observed in a biopsy of the contralateral testis. Tumor tissue actively metabolized tritiated progesterone, pregnenolone and cholesterol to testosterone and androstenedione.1 Correlation of these data with plasma androgen levels from this patient's peripheral and spermatic veins led the authors to conclude that, as in lower species, high local levels of androgen will initiate spermatogenesis in man.

128 citations

Journal ArticleDOI
12 Feb 1973-JAMA
TL;DR: A comparison of fertilizing capacity was made between fresh semen and semen stored in liquid nitrogen, and fresh semen produced 35 conceptions in 48 attempts and frozen semen resulted in 36 pregnancies in 59 attempts.
Abstract: A comparison of fertilizing capacity was made between fresh semen and semen stored in liquid nitrogen. A total of 107 attempts at conception were made in 74 women. Fresh semen produced 35 conceptions in 48 attempts; frozen semen resulted in 36 pregnancies in 59 attempts. The 36 women who failed to conceive were found to have a high incidence of polycystic ovarian disease. The 71 conceptions resulted in 59 live births, 36 boys and 23 girls, 11 early spontaneous abortions, and 1 tubal pregnancy.

91 citations

Journal ArticleDOI
12 Feb 1973-JAMA
TL;DR: Specimens with initial sperm counts between 40 and 200 million/ml and initial motilities between 60% and 89% appeared to withstand long-term storage best, but after this time a progressive significant loss in motility was observed.
Abstract: Human semen was frozen and stored in liquid nitrogen for periods of time up to eight years and two months. A total of 1,764 vials containing 1.1 ml of semen from 533 ejaculates provided by 207 donors were frozen. The freezing and thawing process induced a loss of approximately 50% of the original motility. Storage in liquid nitrogen for periods up to 36 months resulted in no further significant loss in mean motility. However, after this time, a progressive significant loss in motility was observed throughout the period of this study. Specimens with initial sperm counts between 40 and 200 million/ml and initial motilities between 60% and 89% appeared to withstand long-term storage best.

76 citations


Cited by
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TL;DR: An unusual data set on Air Force veterans enables this work to compare the basal and reciprocal models as explanations for the relationship between T and divorce, and discusses sociological implications of these models.
Abstract: In men, high levels of endogenous testosterone (T) seem to encourage behavior intended to dominate - to enhance one's status over - other people. Sometimes dominant behavior is aggressive, its apparent intent being to inflict harm on another person, but often dominance is expressed nonaggressively. Sometimes dominant behavior takes the form of antisocial behavior, including rebellion against authority and law breaking. Measurement of T at a single point in time, presumably indicative of a man's basal T level, predicts many of these dominant or antisocial behaviors. T not only affects behavior but also responds to it. The act of competing for dominant status affects male T levels in two ways. First, T rises in the face of a challenge, as if it were an anticipatory response to impending competition. Second, after the competition, T rises in winners and declines in losers. Thus, there is a reciprocity between T and dominance behavior, each affecting the other. We contrast a reciprocal model, in which T level is variable, acting as both a cause and effect of behavior, with a basal model, in which T level is assumed to be a persistent trait that influences behavior. An unusual data set on Air Force veterans, in which data were collected four times over a decade, enables us to compare the basal and reciprocal models as explanations for the relationship between T and divorce. We discuss sociological implications of these models.

1,250 citations

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TL;DR: Predictions were that that testosterone would rise at puberty to moderate levels, which supported reproductive physiology and behavior, and that testosterone levels will be associated with different behavioral profiles among men, associated with life history strategies involving emphasis on either mating or parental effort.

1,109 citations

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TL;DR: Current evidence regarding the basis for the dysfunction of ovarian steroidogenesis and follicular maturation, and the aberration of gonadotropin secretion as related to the inappropriate steroid feedback system will be reviewed.
Abstract: An extensive literature dealing with studies on the pathophysiology of the polycystic ovary syndrome (PCO) has accumulated over the years. The great clinical and biochemical variability of PCO, as indicated in several excellent reviews over a decade ago (Goldzieher & Axelrod, 1963; Mahesh & Greenblatt, 1964; Jeffcoate, 1963; Shearman & Cox, 1966), continues as a major problem in defining this syndrome. Further, the pathogenesis of this reversible disorder remains elusive. However, recent advances in our understanding of ovarian physiology, the pathways for androgen-oestrogen secretion and metabolism, and the integrated function of the hypothalamic-hypophyseal-ovarian axis permit a rational description of the pathophysiology of the PCO syndrome. Thus, current evidence regarding the basis for the dysfunction of ovarian steroidogenesis and follicular maturation, and the aberration of gonadotropin secretion as related to the inappropriate steroid feedback system will be reviewed. The long debated issue of the possible role of adrenal androgen in the genesis and persistence of PCO syndrome will also be considered.

729 citations

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TL;DR: In conclusion, the information available indicates that the interactions between different cell types in the testis play an important role in the control and maintenance of testicular functions.
Abstract: THE ability of cells to interact and communicate is a biological phenomenon that developed with the evolution of multicellular organisms. The cell-cell interactions that have evolved are essential for the survival of both simple organisms such as dictyostelium and complex organisms such as mammals. These cellular associations allow an organism to develop capacities that are greater than the simple sum of their individual parts. As early as 1878, Claude Bernard proposed that the “milieu interieur” (i.e. internally produced fluid environment) and a cybernetic-like control system (i.e. cell-cell interactions and communication) in multicellular organisms are needed to adaptively regulate the growth, development, and maintenance of normal tissue function (1, 2). The experimental analysis of cellular interactions was initiated with the investigation of cell aggregation in simple organisms such as sponges (3, 4) and progressed into the areas of embryology (5) and cell biology (6, 7). Analysis of cell biology on ...

650 citations

Journal ArticleDOI
TL;DR: The present review shows that different aspects of fear and anxiety are affected differentially by the occupation of the mineralocorticoid receptor (MR) or glucoc Corticosteroids (GR) at different phases of the stress response.

579 citations