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Biomedical subjects

R L Graham

Publications and source records attributed to R L Graham.

9 recordsLinked to original sources
PubMed1994

Neurophysiological model of tinnitus: dependence of the minimal masking level on treatment outcome.

Validity of the neurophysiological model of tinnitus (Jastreboff, 1990), outlined in this paper, was tested on data from multicenter trial of tinnitus masking (Hazell et al., 1985). Minimal masking level, intensity match of tinnitus, and the threshold of hearing have been evaluated on a total of 382 patients before and after 6 months of treatment with maskers, hearing aids, or combination devices. The data has been divided into categories depending on treatment outcome and type of approach used. Results of analysis revealed that: i) the psychoacoustical description of tinnitus does not possess a predictive value for the outcome of the treatment; ii) minimal masking level changed significantly depending on the treatment outcome, decreasing on average by 5.3 dB in patients reporting improvement, and increasing by 4.9 dB in those whose tinnitus remained the same or worsened; iii) 73.9% of patients reporting improvement had their minimal masking level decreased as compared with 50.5% for patients not showing improvement, which is at the level of random change; iv) the type of device used has no significant impact on the treatment outcome and minimal masking level change; v) intensity match and threshold of hearing did not exhibit any significant changes which can be related to treatment outcome. These results are fully consistent with the neurophysiological interpretation of mechanisms involved in the phenomenon of tinnitus and its alleviation.

Acoustic Stimulation↗
PubMed1987

The effect of luteal phase estrogen antagonism on endometrial development and luteal function in women.

Previous studies of the role of estrogen in primate luteolysis, designed to investigate the effects of estrogen antagonism or selective inhibition of luteal phase estrogen production on luteal function, have ignored the impact of such treatments on secretory endometrial development. We examined the effect of luteal phase estrogen antagonism on endometrial maturation and luteal function in six women. In each of two menstrual cycles in each woman, blood samples were obtained on alternate days from cycle days 3-9, daily until 1 day after the urinary LH surge (day 0), and again on alternate days until the onset of menses. In the second of each pair of cycles, clomiphene citrate (100 mg) was administered daily from 2 days after the LH surge until menses. Endometrial biopsy was performed 13 days after the LH surge in each cycle. Serum FSH, LH, estradiol, and progesterone (P) were measured by RIA. The endometrial histological date and concentration of cytosolic (C) and nuclear (N) estrogen (ER) and P (PR) receptors were determined. We found significant (P less than 0.05) increases in luteal phase serum FSH, LH, estradiol, and P levels in the clomiphene cycle compared to those in the control cycle. Endometrial histology was significantly (P less than 0.002) different during estrogen antagonism; a maturation delay of more than 2 days was found in all six women during the clomiphene cycle. Luteal phase duration was unchanged by clomiphene (P = 0.29). Endometrial ER-C [7.38 +/- 2.52 (+/- SEM) vs. 38.75 +/- 10.17 fmol/mg protein], ER-N (248 +/- 84 vs. 685 +/- 80 fmol/mg DNA), and PR-C (97 +/- 38 vs. 189 +/- 38 fmol/mg protein) were significantly lower (P less than 0.03) in the clomiphene cycle than in the control cycle, whereas PR-N was not different (P greater than 0.10). These data suggest that luteal phase estrogen 1) modulates endometrial PR and 2) plays an important role in secretory endometrial development.

Adult↗
PubMed1986

Dissecting hematoma (aneurysm) of coronary arteries.

Isolated dissecting hematoma (aneurysm) of a coronary artery is a rare occurrence that often results in myocardial infarction and sudden death. A case of dissecting hematoma involving the left main, left anterior descending, and left circumflex coronary arteries is described in a patient who had received vigorous closed-chest cardiac resuscitation. This is believed to be the first reported case of coronary artery dissection caused by epicardial trauma from closed-chest cardiac resuscitation. This case demonstrates that dissecting hematoma of the coronary artery can be a complication of cardiac resuscitation.

Aged↗
PubMed1982

Conservative management of patients with premature rupture of fetal membranes.

The management of pregnant patients with premature rupture of membranes (PROM) prior to 32 weeks' gestation or at 32 to 34 weeks' gestation is controversial. In a retrospective analysis of 109 patients with PROM at or prior to 34 weeks' gestation, 53 (49%) were managed conservatively, and labor was eigher induced or occurred spontaneously within 24 hours in 56 (51%). Patients initially presenting with chorioamnionitis were excluded from this study, as were all patients with evidence of a fetal anomaly or a medical indication for delivery. The 53 patients managed conservatively had a mean pregnancy prolongation of 21 days (range, 2 to 105 days median, 7 days). The infants of patients managed conservatively had a lower incidence of respiratory distress syndrome (P less than .0025), mortality (P less than .05), and intracranial hemorrhage (P less than .03). Sixty-four percent of the conservatively managed group versus 45% of the induced/spontaneous labor group were found to be normal upon physical and neurologic examination when discharged from the hospital (P less than .035). The difference in incidence of neonatal sepsis between these 2 groups was not statistically significant (P = .42). Immediate induction of labor and/or delivery for patients with PROM at less than 32 weeks' gestation resulted in a significant increase in perinatal mortality and morbidity.

Female↗
PubMed1980

Changes in thyroid function tests during danazol therapy.

Danazol is a synthetic steroid with antigonadotropic properties useful in treating endometriosis, especially in young infertile women. Prior to its availability for clinical use in September 1976, thyroid function studies other than thyroid-stimulating hormone (TSH), which was normal, had not been reported. Soon after danazol began to be used in the infertility clinic to treat documented endometriosis, it was observed that changes occurred in thyroid function studies. While no patients manifested clinical evidence of hypothyroidism, all 8 patients receiving 800 mg of danazol daily for 1 to 5 months had laboratory evidence of decreased thyroid function. The triiodothyronine (T3) uptake was elevated and the total serum thyroxine (T4) was decreased. The finding that TSH and the free thyroid index (FTI) were normal confirmed that these patients were euthyroid during danazol therapy. The abnormality of thyroid function tests is believed to reflect an androgen-like reduction in thyroxine-binding protein rather than a true decrease in thyroid function or interference with the pituitary-thyroid axis.

Danazol↗
PubMed1979

Amenorrhea secondary to voluntary weight loss.

Obese patients who voluntarily reduce to a normal weight may develop secondary amenorrhea. Six young women who dieted to lose from 13 to 50 pounds, including four from an obese weight, were evaluated because of absent cervical mucus ferning, hypoestrogenic vaginal smears, and failure to have withdrawal menses from a progestogen. Serum FSH values were normal in all, while four had normal serum LH and two had low serum LH levels. T4 and/or T3 uptake was normal in all. The pituitary-adrenal axis was apparently intact since baseline urinary steroids were normal as was the response to both ACTH and metyrapone. Fasting serum growth hormone was markedly elevated in two and slightly elevated in three, with the other patinet demonstrating an unusually high response to glucagon/propranolol in the 30 minute specimen. These endocrine findings are similar to those observed in patients with anorexia nervosa, but the weight loss is entirely voluntary and there was no associated psychiatric abnormality.

Adolescent↗
PubMed1975

Microbiological synthesis of 16alpha, 18-dihydroxydeoxycorticosterone.

16Alpha, 18-Dihydroxydeoxycorticosterone (16alpha, 18-dihydroxy-DOC) (1) and 1, 2-3H-16alpha, 18-dihydroxy-DOC (1,2-3H-16alpha, 18-dihydroxy-DOC) of high specific activity were obtained in good yield by microbiological hydroxylation of 18-OH-DOC and 1,2-3H-18-OH-DOC by Streptomyces roseochromogenus (ATCC 13400). The identity of the fermentation product to human adrenal produced 16alpha, 18-dihydroxy-DOC was established by chromatographic studies, derivative formation and gas-liquid chromatography. Yield of the product was about 30% of sutstrate and, allowing for losses in recovery, about 60% of the substrate 18-OH-DOC was converted to this product. A second product of fermentation isolated in lower yield appeared to be a dimer of 16alpha, 18-dihydroxy-DOC found in the acidic conditions of the fermentation. This method of synthesis of 16alpha, 18-dihydroxy-DOC is a practical way to make large quantities of the compound for further study of its possible role in human and experimental hypertension.

18-Hydroxydesoxycorticosterone↗
PubMedDate not supplied

Contralateral suppression of transient evoked otoacoustic emissions: intra-individual variability in tinnitus and normal subjects.

Contralateral acoustic stimulation reduces the amplitude of the transient evoked otoacoustic emission (TEOAE) in humans. The mechanism is thought to be mediated, at least in part, through the medial olivocochlear efferent system innervating the outer hair cells. To assess its usefulness as a possible clinical test, TEOAE suppression was measured in each ear of 12 subjects over a 6-week period, and these data are shown in detail for four subjects representing extremes of variability in a tinnitus and a non-tinnitus group. Intra-subject test results (n = 18) exhibited a varying extent of suppression values and the variance of each session, consisting of three tests, was not statistically different from one session to another. There was no dependence on variables such as ear (right or left), session, day of testing or their interaction. There was a significant difference in the variability between the tinnitus and the normal group.

Acoustic Stimulation↗