Internists, Endocrinologist (diabetes, hormones)
38 years of experience

506 Barnett Tower 3600 Gaston Ave
Dallas, TX 75246
214-828-2444
Locations and availability (2)

Education ?

Medical School Score Rankings
The University of Texas Southwestern (1972)
  • Currently 4 of 4 apples
Top 25%

Awards & Distinctions ?

Awards  
Castle Connolly's Top Doctors™ (2012 - 2013)
Patients' Choice Award (2010 - 2011, 2013)
Compassionate Doctor Recognition (2011, 2013)
Castle Connolly Top Doctors: Texas™ (2009)
Associations
Pituitary Network Association
American Association of Clinical Endocrinologists
Hormone Foundation
American Board of Internal Medicine
American Society for Reproductive Medicine

Affiliations ?

Dr. Marynick is affiliated with 6 hospitals.

Hospital Affilations

Score

Rankings

  • Baylor University Medical Center *
    3500 Gaston Ave, Dallas, TX 75246
    • Currently 4 of 4 crosses
    Top 25%
  • Harris Methodist H E B
    1600 Hospital Pkwy, Bedford, TX 76022
    • Currently 4 of 4 crosses
    Top 25%
  • Texas Health Harris Methodist Hospital Southwest Fort Worth
    6100 Harris Pkwy, Fort Worth, TX 76132
    • Currently 4 of 4 crosses
    Top 25%
  • Texas Health Presbyterian Hospital Of Dallas *
    8200 Walnut Hill Ln, Dallas, TX 75231
    • Currently 3 of 4 crosses
    Top 50%
  • Texas Health Dallas
  • Harris Methodist - Springwood
    1608 Hospital Pkwy, Bedford, TX 76022
  • * This information was reported to Vitals by the doctor or doctor's office.

    Publications & Research

    Dr. Marynick has contributed to 13 publications.
    Title Calcium-dependent Release of N-terminal Fragments and Intact Immunoreactive Parathyroid Hormone by Human Pathological Parathyroid Tissue in Vitro.
    Date October 1989
    Journal The Journal of Clinical Endocrinology and Metabolism
    Excerpt

    The regulation of PTH secretion by extracellular calcium was studied in parathyroid tissue obtained from patients with hyperparathyroidism (adenoma or hyperplasia) using both an amino (N)-terminal RIA as well as an immunoradiometric assay (intact assay) specific for the intact hormone. The parathyroid glands separated into three major groups when examined in terms of absolute amounts of PTH secreted, degree of suppressibility, and set-point for calcium (the concentration of calcium causing half-maximal inhibition of PTH release). In cell preparations from group A (two different adenomas, two hyperplastic glands from a patient with renal failure, and a hyperplastic gland from a patient with hypophosphatemic rickets), both assays showed comparable PTH release (agreeing within 2-fold), similar degrees of suppressibility and similar, if not identical, set-points. In group B (two adenomas and one hyperplastic gland from a patient with renal failure), PTH secretion, as measured in the N-terminal assay, was 3- to 6-fold more than that measured in the intact assay. The set-points and maximal degrees of suppressibility were, however, still comparable. In group C [two adenomas and one gland from a patient with hypophosphatemic rickets (the sister of the patient in group A)], no suppressibility was observed when PTH release was measured using the intact assay (i.e. less than 50% suppression of PTH release at 2-3 mM Ca2+). In one of these three glands, the N-terminal assay was used in addition to the intact assay, and no suppressibility was present with either assay. Thus, in general, the effects of extracellular Ca2+ on PTH secretion from pathological parathyroid tissue were similar when assessed with both an N-terminal and an intact assay, at least with respect to setpoint and maximal suppressibility. In a few cases, maximal PTH release was greater when measured with the N-terminal assay, consistent with substantial release of N-terminal fragments in addition to intact PTH. In addition, nonsuppressible glands were not uncommon when PTH release was measured by the intact assay, confirming previous studies with less specific assays.

    Title Androgen Excess in Cystic Acne.
    Date May 1983
    Journal The New England Journal of Medicine
    Excerpt

    We measured hormone levels in 59 women and 32 men with longstanding cystic acne resistant to conventional therapy. Affected women had higher serum levels of dehydroepiandrosterone sulfate, testosterone, and luteinizing hormone and lower levels of sex-hormone-binding globulin than controls. Affected men had higher levels of serum dehydroepiandrosterone sulfate and 17-hydroxyprogesterone and lower levels of sex-hormone-binding globulin than controls. To lower dehydroepiandrosterone sulfate, dexamethasone was given to men, and dexamethasone or an oral contraceptive pill, Demulen (or both), was given to women. Of the patients treated for six months, 97 per cent of the women and 81 per cent of the men had resolution or marked improvement in their acne. The dose of dexamethasone required to reduce dehydroepiandrosterone sulfate levels was low, rarely exceeding the equivalent of 20 mg of hydrocortisone per day. We conclude that most patients with therapeutically resistant cystic acne have androgen excess and that lowering elevated dehydroepiandrosterone sulfate results in improvement or remission of acne in most instances.

    Title Abnormal Regulation of Parathyroid Hormone Release by Calcium in Secondary Hyperparathyroidism Due to Chronic Renal Failure.
    Date March 1982
    Journal The Journal of Clinical Endocrinology and Metabolism
    Excerpt

    Dispersed parathyroid cells were employed to study calcium-regulated parathyroid hormone (PTH) release in severe secondary hyperparathyroidism due to chronic renal insufficiency. Cell preparations were obtained from 16 parathyroid glands of 6 patients undergoing subtotal parathyroidectomy for parathyroid bone disease and/or hypercalcemia. The effects of increasing ambient calcium concentration on immunoreactive PTH release in vitro were assessed and compared with results observed in cells prepared from 7 adenomas and 6 normal parathyroid glands. There was no difference in maximal PTH release for the 3 types of tissue (mean +/- SEM, 8.48 +/- 1.9 , 8.1 +/- 3, and 10.1 +/- 0.78 ng/10(5) cells. h respectively). In 14 of 16 hyperplastic glands, 6 of 7 adenomas, and all of the normal glands, PTH release was inhibited more than 50% by 2-3 mM calcium (suppressible glands). Of the normal glands, half of the maximal inhibition of PTH release (the set-point) occurred at less than 1.03 mM calcium in 5 of 6 cases. In 12 of 14 suppressible hyperplastic glands and all of the 6 suppressible adenomas, on the other hand, the set-point was 1.03 mM or higher (p less than 0.01 and P less than 0.002, respectively). Thus, in severe secondary parathyroid hyperplasia due to chronic renal insufficiency, there is frequently an increase in the set-point for calcium without a change in the maximal secretory rate per cell. Abnormal calcium-regulated PTH release at the cellular level, therefore, is not limited to parathyroid neoplasia (i.e. adenoma or primary hyperplasia), but may occur in secondary hyperplasia as well.

    Title Abnormal Calcium-regulated Pth Release in Normal Parathyroid Tissue from Patients with Adenoma.
    Date November 1981
    Journal The American Journal of Medicine
    Excerpt

    The regulation of parathyroid hormone (PTH) secretion by calcium was studied in normal and abnormal parathyroid tissue from five patients with a parathyroid adenoma. Dispersed cells were prepared from the adenoma and from a portion of a normal parathyroid gland and were incubated for two hours with varying concentrations of calcium. PTH release as a function of the concentration of calcium was determined by radioimmunoassay (C-terminal). Cells from the normal glands showed a lower set-point for calcium (the concentration of calcium causing half of the maximal inhibition of PTH release) than those from the adenomas in four of five cases. Moreover, both set-point and maximal PTH release at low concentrations of calcium were significantly lower in normal glands from patients with an adenoma than in normal glands from patients with normal calcium homeostasis (0.77 +/- 0.04 [SEM] versus 0.99 +/- 0.03 mM calcium and 3.4 +/- 0.43 versus 10.1 +/- 0.78 ng/10(5) cells/hr, respectively). These observations may explain, in part, the transient hypocalcemia frequently seen in patients after removal of a parathyroid adenoma. In addition, they suggest that the set-point for calcium and maximal PTH release in normal parathyroid tissue may be altered by prior exposure to chronic hypercalcemia or other physiologic variables. Finally, the "normal" set-point that we have noted previously in parathyroid tissue from some patients with primary parathyroid hyperplasia may be inappropriately high for the hypercalcemia seen in those cases.

    Title Effect of Intravenous Pyridoxine on Plasma Prolactin in Hyperprolactinemic Subjects.
    Date November 1979
    Journal The Journal of Clinical Endocrinology and Metabolism
    Excerpt

    Intravenous pyridoxine has been reported to lower plasma PRL in normal subjects and in patients with the amenorrhea-galactorrhea syndrome. We tested the effect of pyridoxine (300-mg iv bolus) on plasma PRL in nine patients with hyperprolactinemia due to a variety of causes. There was no effect of pyridoxine on elevated plasma PRL in any of the nine hyperprolactinemic subjects. The potential utility of pyridoxine in the long term treatment of the galactorhea-amenorrhea syndrome will require further study.

    Title Evidence That Testosterone Can Suppress Pituitary Gonadotropin Secretion Independently of Peripheral Aromatization.
    Date October 1979
    Journal The Journal of Clinical Endocrinology and Metabolism
    Excerpt

    Testosterone (T) was given to normal men with and without the concomitant administration of the aromatase inhibitor, delta 1-testolactone (Teslac), to examine the role of peripheral aromatization of T in gonadotropin regulation. When T was administered alone by continuous iv infusion (15 mg/day for 4 days), serum T increased 3-fold (P less than 0.01) and estradiol (E) increased by 50% (P less than 0.01). These changes were associated with a 50% decrease in serum LH and FSH concentrations (P less than 0.01). When T was infused into men taking Teslac (2000 mg/day), serum T levels doubled (P less than 0.01), but E levels did not change (13.4 +/- 1.5 vs. 13.5 +/- 1.0 pg/ml; P = NS). This pattern of plasma steroids, increased T and unchanged E, was also associated with significantly decreased serum LH and FSH concentrations (14.5 +/- 0.4 vs. 8.0 + 0.4 mIU/ml and 9.9 +/- 2.5 vs. 5.8 +/- 0.1 mIU/ml, respectively; P less than 0.01). These data support the hypothesis that T or one of its metabolites can modulate LH and FSH secretion independently of peripheral aromatization to E.

    Title Replacement Oral Ethinyloestradiol Therapy for Gonadal Dysgenesis: Growth and Adrenal Androgen Studies.
    Date October 1979
    Journal Acta Endocrinologica
    Excerpt

    We have studied growth and adrenal dehydroepiandrosterone (DHA) responses to iv synthetic adrenocorticotrophic hormone (ACTH, Cortrosyn) in 6 girls with gonadal dysgenesis before and during treatment with low-dose ethinyloestradiol (EOe2). In all patients there was a statisfactory induction of secondary sexual characteristics including increase in breasts and public hair and onset of withdrawal bleeding within 6 months of therapy. Height velocity increased from 2.8 +/- 0.9 cm/year pre-treatment to 5.3 +/- 1.5 cm/year (P less than 0.02) in the first year. There was deceleration to 1.9 +/- 1.1 cm/year in the second year. There was no disproportionate advancement in bone age and thus, presumably, no loss of ultimate height. We could demonstrate no change in basal or ACTH-stimulated levels of DHA, a specific adrenal androgen, to account for the increased public hair and growth in these patients.

    Title The Effect of Bicarbonate and Distilled Water on Sickle Cell Trait Hematuria and in Vitro Studies on the Interaction of Osmolality and Ph on Erythrocyte Sickling in Sickle Cell Trait.
    Date December 1977
    Journal The Journal of Urology
    Excerpt

    The effect of intravenously administered distilled water was examined alone and during alkalization in a patient with gross hematuria associated with the sickle cell trait. On each of 4 occasions hematuria ceased promptly after the infusion of distilled water. Bicarbonate therapy also consistently decreased hematuria. In vitro studies on erythrocytes from another patient with sickle cell trait and hematuria demonstrated that slight increases in urinary pH similar to those that occur in the urine during alkalization can reverse or prevent erythrocyte sickling in the sicle cell trait. If patients with the sickle cell trait are hydrated adequately and have a good rate of urine flow distilled water can be given intravenously with virtually no danger of acute tubular necrosis secondary to erythrocyte hemolysis.

    Title Studies on the Transfer of Steroid Hormones Across the Blood-cerebrospinal Fluid Barrier in the Rhesus Monkey. Ii.
    Date September 1977
    Journal Endocrinology
    Excerpt

    The movement of progesterone (P), cortisol (F) and 17-hydroxyprogesterone (17-OHP) across the blood-cerebrospinal fluid (CSF) barrier was determined using six adult male rhesus monkeys with indwelling canulae in the lateral ventricles of their brains. Tritiated steroids were given iv as a bolus followed by a constant 6 h infusion with continuous collection of CSF and periodic sampling of blood before and during the infusion. The amounts of authentic steroid in the plasma and CSF were determined by recrystallization to constant isotopic ratio and the amount of free plasma steroid was determined by equilibrium dialysis against Ringer's solution. Tritiated progesterone was undetectable in the pooled samples of CSF. The average concentration of tritiated 17-OHP in the CSF was 10.3% of the concurrent plasma level while the concentration of tritiated F was 22.5% of the concurrent plasma level. Plasma free steroid was found to be 2.2% for P, 6.3% for 17-OHP and 22.3% for F, showing a rough correlation between steroid entry into the CSF and free steroid concentration in plasma.

    Title The Effect of Osmotic Stimuli on Prolactin Secretion and Renal Water Excretion in Normal Man and in Chronic Hyperprolactinemia.
    Date March 1977
    Journal The Journal of Clinical Endocrinology and Metabolism
    Excerpt

    An osmoregulatory role for prolactin (PRL) in man has been postulated, and PRL secretion has been reported to be influenced by osmotic stimuli. Clinical observation, however, does not support this notion. The effects of water loading, hypertonic saline infusion and nicotine on serum PRL and on renal water metabolism were investigated in 6 normal subjects and in 8 patients with chronic hyperprolactinemia (four with and four without demonstrable pituitary tumors). None of the patients had thyroid, adrenal or vasopressin deficiency. Renal walter handling in these patients was indistinguishable from normal. Likewise, serum PRL was not affected by the stimuli employed in either the normal subjects or the patients. No correlation between degree or duration of hyperprolactinemia and renal water metabolism was found. It is concluded that PRL is not an important osmoregulatory hormone in man.

    Title Studies on the Transfer of Steroid Hormones Across the Blood-cerebrospinal Fluid Barrier in the Rhesus Monkey.
    Date October 1976
    Journal Endocrinology
    Excerpt

    Indwelling canulae were placed in the lateral ventricles of the brains of six adult male rhesus monkeys, and the movement of estradiol-17beta (E2), testosterone (T), and 5alpha-dihydrotestosterone (DHT) across the blood-cerebrospinal fluid (CSF) barrier was measured. Serial samples of blood and CSF were collected every 30 minutes during a 6 hour infusion of the tritiated steroids, and the quantity of free steroid in the blood and CSF was determined by recrystallization to constant specific activity. During the course of the 6-hour infusion, the average CSF concentration of steroid, expressed as dpm/ml, was about 3.5% of the concurrent plasma level of E2, 1.6% of the concurrent plasma level of T, and 0.08% of the concurrent plasma level of DHT. It is proposed that these differences in steroid transfer can be attributed to differential binding of these steroids to testosterone-estrogen-binding globulin (TeBG) in plasma.

    Title Changes in Regional Coronary Blood Flow with Hypertonic Mannitol in Conscious Dogs.
    Date July 1975
    Journal Cardiovascular Research
    Excerpt

    Systemic haemodynamics and regional myocardial blood flow responses to hypertonic mannitol were studied in 10 conscious and 23 anaesthetized dogs. Mannitol infusion significantly increased regional myocardial blood flow in the conscious, intact dogs. Mannitol increased total coronary flow 20% in anasethetized animals compared to 80% in the awake ones. In both groups mannitol exerted a significant positive inotropic effect as evidenced by increases in maximal LV dp/dt and dp/dt/p. These studies have also demonstrated that the intact conscious dog that has not received any sedation has an inner:outer wall left ventricular flow ratio greater than 1-0.

    Title Samuel Philip Marynick, Ms, Md: a Conversation with the Editor.
    Date
    Journal Proceedings (baylor University. Medical Center)

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