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Biomedical subjects

D L Kaiser

Publications and source records attributed to D L Kaiser.

At least 91 records · Page 5Linked to original sources

Catheter-associated bacteriuria. Failure to reduce attack rates using periodic instillations of a disinfectant into urinary drainage systems.

We assessed the efficacy of periodic instillations of hydrogen peroxide into urinary drainage systems in the prevention of catheter-associated bacteriuria in a prospective and randomized clinical study of 668 patients with indwelling urethral catheters. Bacteriuria was documented in 68 (10%) of the 668 patients after a mean duration of four days of catheterization. There was no difference between the hydrogen peroxide group and the control group in the mean duration of catheterization before the onset of bacteriuria, in the attack rate for bacteriuria, or in the spectrum of etiologic agents recovered. Bag contamination with the same organism responsible for bacteriuria preceded infection in only five (7%) of the 68 patients, three patients using hydrogen peroxide and two in the control group. We conclude that infections arising intraluminally from contamination of the drainage bag are uncommon among catheterized patients and that the periodic instillation of disinfectants into closed sterile drainage systems is not effective in reducing the incidence of catheter-associated bacteriuria.

Bacteria↗

Determinants of glucose and ketoacid concentrations in acutely hyperglycemic diabetic patients.

Diabetic hyperosmolar coma is a syndrome of marked hyperglycemia and minimal ketoacidosis. In general, the serum glucose concentrations are not predictive of the serum ketoacid concentrations in acutely decompensated diabetes. The endocrine factors that modulate glucose concentrations may be different from those that modulate ketoacid concentrations in patients with acutely decompensated diabetes. To test this hypothesis, regression analysis was used to determine the endocrine and metabolic characteristics that correlated with serum concentrations of glucose and ketoacids in 26 diabetic patients with spontaneous, acute hyperglycemia. All patients had a serum glucose level greater than 390 mg/dl, and ketoacid levels were from 0.17 to 25.5 mM. Multiple regression analysis showed that increased serum glucose concentrations correlated with increased plasma glucagon levels (p = 0.0007, r2 = 0.45), but with no other factors. Increased total ketoacid levels (acetoacetate plus 3-hydroxybutyrate) correlated with increased free fatty acid levels (p = 0.0001), decreased C-peptide levels (p = 0.002), and increased body mass index (p = 0.002) (r2 = 0.72). Body mass index only correlated with ketoacid levels, when it was analyzed with C-peptide and free fatty acid levels. A model is proposed that predicts the serum glucose and ketoacid concentrations in patients with acutely decompensated diabetes. Glucagon modulates the serum glucose concentration in these patients with an absolute or relative insulin deficiency. Total serum ketoacid levels are determined by the serum free fatty acid concentration, residual pancreatic insulin secretion (as reflected by C-peptide), and the patient's body habitus. This model allows for the marked hyperglycemia and minimal ketosis of diabetic nonketotic hyperosmolar coma, as well as the glucose and ketoacid concentrations in other presentations of acutely decompensated diabetes.

Acute Disease↗

Dopaminergic suppression of angiotensin II-induced aldosterone secretion in man: differential responses during sodium loading and depletion.

Previous studies have shown that aldosterone secretion may be inhibited by dopaminergic mechanisms in man. Dopamine does not inhibit aldosterone responses to angiotensin II in sodium-replete normal subjects. Since sodium deficiency is associated with a reduction in renal dopamine formation, we investigated the effect of dopamine on angiotensin II-induced aldosterone secretion in the sodium-depleted state. Six normal subjects in balance at 10 mEq sodium intake (UNaV 17 +/- 2 meq/24 hr) received dopamine 4 micrograms/kg/min or vehicle for 210 minutes on two consecutive days. After 60 minutes of the dopamine or vehicle infusion, the subjects received successive 30-minute infusions of angiotensin II in increasing doses of 0.5, 1, 2, 4 and 6 picomol/kg/min. Control plasma aldosterone concentrations before vehicle or dopamine were 15 +/- 3 (mean 1 +/- SE) and 25 +/- 3 ng/dL, respectively. Aldosterone responses to angiotensin II were greater with vehicle than dopamine at angiotensin II doses of 4 and 6 picomol/kg/min (P less than 0.025). The slope of angiotensin-aldosterone dose-response curve was steeper with vehicle (0.33) than with dopamine (0.16), P less than 0.01. Serum prolactin concentrations were lower with dopamine (1.6 +/- 0.8 ng/mL) than with vehicle (6.4 +/- 1.2 ng/mL, P less than 0.05) by 120 minutes of infusion and remained suppressed with dopamine for the remainder of the dopamine infusion. Diastolic blood pressure was higher (P less than 0.05) with vehicle than with dopamine at angiotensin II doses of 2, 4, and 6 picomol/kg/min. Dopamine administration was associated with an increase in plasma cortisol concentration from 90 to 150 minutes of infusion (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Mesulergine, a new dopamine agonist: effects on anterior pituitary function and kinetics.

We investigated the effects of single doses of mesulergine on basal and thyrotropin-releasing hormone (TRH)-stimulated serum levels of several anterior pituitary hormones in healthy men and defined its kinetics. We also compared the effects on serum prolactin (PRL) levels of three doses (0.1, 0.35, and 0.5 mg) of mesulergine to those in response to 2.5 mg bromocriptine. Secretory rates of PRL before the first dose of TRH were not affected by any dose of mesulergine or bromocriptine. TRH-stimulated PRL secretion was not altered by 0.1 mg mesulergine but was blunted by both the 0.35- and 0.5-mg doses at 10 A.M. and 1 P.M. Bromocriptine inhibited TRH-stimulated PRL secretion at 10 A.M. and 8 P.M. When analyzed as the 8 A.M. to 8 P.M. and the 8 P.M. to 9 A.M. (day 2) intervals, PRL secretion was not changed by 0.1 or 0.35 mg mesulergine but was suppressed during both periods by the 0.5-mg dose. A dose-response relationship was evident, however, between mesulergine and PRL secretion during both the 8 A.M. to 8 P.M. (R2 = 0.27) and the 8 P.M. to 9 A.M. (day 2; R2 = 0.18) intervals. Bromocriptine lowered PRL secretion during both intervals. Secretory rates of growth hormone during these intervals were not affected by 0.1 mg or 0.35 mg mesulergine but were increased during both intervals by the 0.5-mg dose. Neither the secretory rates of thyrotropin in response to TRH nor those of cortisol, luteinizing hormone, or follicle-stimulating hormone were changed by 0.1 or 0.35 mg mesulergine.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

Postoperative recurrence in Crohn's disease. The effect of the initial length of bowel resection and operative procedure.

We reviewed the surgical experience of 61 patients with Crohn's disease who have received surgical treatment over a 32-year period. Sex, age at onset of symptoms, associated systemic abnormalities, presenting symptoms, indication for previous surgery, and site of disease were not significant predictors of postoperative recurrence. Certain extensive resections of the small bowel are associated with a decreased probability of rehospitalization and reoperation. Resection of more than 25 cm of the small bowel and more than 50 cm of the "total" (small plus large) bowel was associated with a decreased likelihood of recurrence. Interestingly, analysis of larger resections (50, 75, 100 cm) failed to document a decreased likelihood of recurrence. The amount of large bowel resected did not predict postoperative recurrence. Bypass and diversion procedures offer a significantly enhanced risk for recurrent disease, whereas procedures employing resection are associated with lower probabilities of recurrent disease. We conclude that technically adequate resections of 25 to 50 cm of the small bowel or the combined small and large bowel are associated with a decreased probability of reoperation or rehospitalization after the initial surgery for Crohn's disease.

Adolescent↗

Acute leukemia in adults: cost effectiveness of treatment.

Costs of treating 174 adult patients with acute leukemia were compiled and analyzed over the five-year period 1974 to 1979. The average overall cost per patient was $18,760, and increased over the period of study. Increased total hospital costs were incurred by patients who achieved a favorable response to induction chemotherapy and by those with a diagnosis of acute lymphocytic leukemia (ALL). To assess the impact of successful treatment on hospital expenditures, total months of survival were compared with total hospital costs to determine cost per month of life. Using this analysis, improved survival, favorable response to chemotherapy, and a diagnosis of ALL were associated with significant decreases in cost per month of life. The long-term survivors (alive greater than or equal to 2 years from diagnosis) best demonstrated this effect, with a mean hospital cost per month of survival from diagnosis of $563, which was significantly less than $6,937 for those who achieved a partial remission, $10,703 for those with treatment failure, and $8,240 for those who were untreated. These costs linked to outcome are comparable to those reported in other disorders that require prolonged and intensive hospital care. With the progressive improvement in response rate and in percentage of long-term survivors that is being observed in adults with acute leukemia, these costs should continue to decrease.

Adolescent↗

Effects of thoracic volume and shape on electromechanical coupling in abdominal muscles.

To assess the effects of lung volume and chest wall configuration on electromechanical coupling of the abdominal muscles, we examined the relationship between abdominal muscle pressure ( Pmus ) and electrical activity ( EMGab ) in eight normal subjects during expiratory efforts at lung volumes ranging from functional residual capacity (FRC) to FRC + 2.0 liters. At and above FRC, increases of lung volume did not significantly alter either the Pmus - EMGab relationship or abdominal surface linear dimensions, although expiratory efforts displaced the abdomen inward from its relaxed position. We attribute the constancy of delta Pmus /delta EMG above FRC to the negligible effects of increasing lung volume on abdominal configuration and muscle length. Expiratory efforts performed at lung volumes below FRC resulted in a wider range of abdominal indrawing . Under these conditions the EMGab required to augment Pmus by 30-40 cmH2O increased as the abdomen was displaced inward. This decrease of delta Pmus /delta EMGab appears to reflect muscle shortening, flattening of the abdominal wall, and possibly deformation of the rib cage.

Abdominal Muscles↗

Selective peripheral dopamine-1 receptor stimulation with fenoldopam in human essential hypertension.

SKF 82526-J, or fenoldopam, a benzazepine derivative, is a selective dopamine-1 (DA-1) agonist devoid of activity at dopamine-2, alpha- or beta-adrenergic receptors. We studied SKF 82526-J in 10 patients with essential hypertension and five normal control subjects on constant 150-meq sodium, 60 meq potassium intake. In the hypertensive patients, during a 6-d placebo period supine blood pressure and heart rate were stable at 156 +/- 6/105 +/- 4 mmHg and 76 +/- 5 beats/min, respectively. In response to a single oral dose of 100 mg of SKF 82526-J, supine blood pressure decreased to a nadir of 141 +/- 5/89 +/- 8 mmHg (P less than 0.0001) at 90 min and remained decreased at 145 +/- 6/99 +/- 3 mmHg (P less than 0.0001) at 4 h. Heart rate increased to 91 +/- 5 beats/min (P less than 0.002), but returned to control levels (82 +/- 5 beats/min) at 4 h. Renal blood flow increased from 371 +/- 57 to a peak of 659 +/- 104 ml/min and renal vascular resistance fell from 34 +/- 5 to 19 +/- 2 dyn sec cm-5 X 10(3) (P less than 0.01). Urine volume, sodium and fractional sodium excretion, and plasma renin activity were increased as a result of SKF 82526-J administration. During the ensuing 3 wk of SKF 82526-J, blood pressure remained decreased and returned to control levels after placebo administration. In contrast, in normal subjects SKF 82526-J administration was associated with a small transient reduction in diastolic pressure only. These results suggest that reduced dopaminergic activity expressed at the peripheral DA-1 receptor may contribute to the pathophysiology and/or maintenance of increased blood pressure in essential hypertension. In addition, the results suggest that peripheral DA-1 receptor stimulation with SKF 82526-J may be efficacious in the treatment of human essential hypertension.

Adult↗

Chronic partial ureteral obstruction in the neonatal guinea pig. I. Influence of uninephrectomy on growth and hemodynamics.

Although obstructive nephropathy is a frequent cause of renal insufficiency in infancy, factors influencing adaptation to chronic partial ureteral obstruction (CPUO) are poorly understood. Guinea pigs were subjected to unilateral CPUO within the first 2 days of life (Group I) and microsphere studies were performed at 23 +/- 3 days of age. To also investigate the role of functional renal mass on growth and hemodynamics, contralateral nephrectomy was performed in Group II at the time of ureteral constriction. Compared to sham-operated controls (ureteral diameter = 1 mm) CPUO caused impaired somatic growth in both groups. Resulting hydroureteronephrosis was variable and most severe (ureteral diameter greater than 3 mm) in azotemic animals of Group II, which demonstrated reduced compensatory renal hypertrophy and poorest somatic growth. Mean arterial blood pressure was not affected by CPUO or uninephrectomy. Renal blood flow (RBF) was higher in Group II than Group I, and did not fall significantly with severity of CPUO in Group II, in which number of perfused glomeruli was similar to controls. In contrast, renal vascular resistance (RVR) increased by 172% in animals of Group I with severe CPUO, and was associated with 34% fewer perfused glomeruli than in the hypertrophied contralateral kidney. With increasing severity of CPUO, RBF tended to be distributed to outer cortical regions in the obstructed kidney of Group I, while the shift in RBF distribution was from outer to inner cortex in the remaining kidney of Group II. Filtration fraction fell as a result of CPUO in both groups, such that reduction in the glomerular filtration rate was due in large part to factors other than RBF.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Similar hormone-rich peptides from thyroglobulins of five vertebrate classes.

Thyroglobulins (Tgs) were purified from five species (rat, chicken, turtle, frog, and goldfish), each representing a different vertebrate class. On reduction with mercaptoethanol, each Tg produced five major iodopeptides, designated A-E, with ranges of estimated molecular mass, in kilodaltons (K), as follows: A, more than 300K; B, 210-280K; C, 30-42K; D, 19-28K; and E, 10-23K. Of these, the two smallest, D and E, had 40-80% of their iodine as iodothyronine, compared with 15-20% for the parent Tgs. They contained 25-63% of Tg's total iodothyronines but only a few percent of its peptide material. Calculations from amino acid analyses and iodine contents showed approximately 1 mol each of D and E/mol 660,000 dalton Tg. In comparisons of amino acid compositions by cluster analysis, iodopeptides D and E resembled each other and their counterparts in other species more than they resembled their parent Tgs. Also, the Tgs from different species were more similar to each other and to iodopeptides D and E than to nonthyroidal proteins randomly selected from the literature. We injected 125I into rats and turtles, and compared its distribution among the iodopeptides to that of 127I. These dual isotope experiments showed that as Tg was iodinated in vivo, iodopeptide B decreased both in molecular size and in its share of Tg's iodine, while the sum of iodopeptides D and E increased, indicating that B may be the precursor of D and E. In vivo iodination of rat Tg with 125I for different periods of time suggested that iodopeptide E and its iodothyronines are derived from a larger portion of the Tg molecule, perhaps iodopeptide B. The amount of 125I in iodopeptide D also increased with time. We conclude that these two discrete hormone-rich peptide fractions of small molecular weight are a consistent feature of Tg's structure throughout the vertebrate classes. Both are probably derived from a larger iodopeptide fraction (iodopeptide B) during the course of Tg maturation and iodination. Their conservation during evolution indicates an important role for them in thyroid hormone biosynthesis.

Animals↗

The self-priming effect of gonadotropin-releasing hormone on luteinizing hormone release: observations using rat anterior pituitary fragments and dispersed cells continuously perifused in parallel.

To study in vitro the self-priming effect of GnRH on LH release, rat anterior pituitaries were prepared either as fragments or dispersed cells and continuously perifused in parallel chambers. The experimental groups consisted of rats killed at 0800 h on diestrus day 1, diestrus day 2, proestrus or estrus, or at 1400 h on proestrus. To insure truly independent observations, each experimental preparation was tested on three occasions. After basal LH release had stabilized, the tissue preparations were exposed to 10 nM GnRH as two 30-min challenges separated by 1 h. LH secretory rates (nanograms per min/pituitary for fragments; nanograms per min/10(7) cells for dispersed cells) were calculated 1) for basal release (during the 20-min period immediately preceding each GnRH challenge), 2) in response to GnRH, and 3) as the sum of basal and GnRH-stimulated release. Comparison of the two preparations revealed that basal and GnRH-stimulated LH release by pituitary fragments was more variable than LH release by dispersed cells. In addition, while dispersed cells responded promptly to the addition/withdrawal of stimuli, fragments did so more gradually. With respect to GnRH self-priming, the second mean secretory rate for basal LH release by fragments (range, 28.8-46.5) was significantly (0.1 greater than P greater than 0.01) higher than the first rate (range, 14.4-22.0) on diestrus day 1, diestrus day 2, proestrus at 0800 h, and estrus. With dispersed cells, the first and second basal rates were similar to each other on diestrus day 1 and estrus, but on diestrus day 2 and on proestrus at 0800 and 1400 h, the second basal rate (range, 36.8-93) was significantly (P less than 0.001) higher than the first range (range, 17.7-31.7). When fragments received GnRH, the second mean secretory rate (range, 35.2-64.2) was significantly (0.1 greater than P greater than 0.03) higher than the first rate (range, 13.4-34.1) on diestrus day 2 and proestrus at 0800 h. With dispersed cells, the mean secretory rate in response to the second GnRH challenge was higher only on diestrus day 2 (37.0 +/- 4.1 vs. 60.3 +/- 3.8; P less than 0.05). When considered as the total of basal plus GnRH-stimulated LH release, the second secretory rate by fragments (range, 54.5 - 110.8) was significantly (0.1 greater than P greater than 0.02) higher than the first rate (range, 27.9 - 51.4) on diestrus day 1, diestrus day 2, and proestrus at 0800 h.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Effect of testosterone on somatomedin-C concentrations in prepubertal boys.

To investigate the role of testosterone (T) in the pubertal elevation of somatomedin-C (SmC), six prepubertal GH-deficient boys were each given 7-day courses of GH alone (0.05 U/kg X day, im), T alone (T propionate; 25 mg/day, im), and a combination of GH and T at the same dosages. Plasma SmC levels were determined on samples drawn at the start and finish of each period, and each course was separated by a 7-day period. SmC was also measured before and after a course of T propionate (25 mg/day, im) in four GH-sufficient boys with delayed adolescence. In the GH-deficient boys, GH and the combination of GH and T resulted in comparable and significant increments of SmC (mean change, 0.68 U/ml after GH and 0.63 U/ml after the combination of GH and T). T alone caused no change in SmC in the GH-deficient boys (mean change, 0.09 U/ml), but resulted in increases in all four GH-sufficient subjects (mean change, 1.29 U/ml). In a single subject with constitutionally delayed puberty, the integrated 24-h GH concentration rose from 2.8 ng/ml before to 5.8 ng/ml after T therapy. Both the number and amplitude of GH secretory events were greater after therapy. These data show that T stimulates SmC production in prepubertal boys who can secrete GH, but not in those who are GH deficient. We postulate that the effect of T in this regard is due to its effect on pituitary GH secretion. Although the T levels were within the pharmacological range, physiological levels of T (e.g. at puberty) may be responsible for the adolescent SmC increment in men.

Adolescent↗

Human pancreatic tumor growth hormone-releasing factor: dose-response relationships in normal man.

Human pancreatic GRF (hpGRF-40; 1 microgram/kg, iv) selectively stimulates GH release in normal men (9). We now report the effects of graded doses of hpGRF-40 on GH release in 12 normal men. Mean peak increments in serum GH after vehicle and the various doses of hpGRF-40 were 1.13, 11.40, 14.60, 17.01, 14.45, and 15.60 ng/ml after vehicle and 0.1, 0.33, 1.0, 3.3, and 10 micrograms/kg hpGRF-40 (iv bolus), respectively. Peak values were observed 30-60 min after hpGRF-40 treatment. There was considerable variability of responsiveness among individual subjects, and no dose-response relationship between the doses and maximal GH values was found. However, the higher doses of 3.3 and 10.0 micrograms/kg resulted in a more prolonged and biphasic pattern of GH release. A side effect of facial flushing of less than 5-min duration occurred in 4 or 6 subjects who received 3.3 micrograms/kg and in all 5 who received 10 micrograms/kg of hpGRF-40. No changes in serum glucose, LH, TSH, PRL, plasma cortisol, or 8 enteropancreatic hormones occurred after hpGRF-40 treatment. There were small increases in serum somatomedin C levels 24 h after the administration of various doses of hpGRF-40 in 11 of 13 studies. Plasma immunoreactive GRF levels measured 5 min after injection were 0.09, 2.0, 4.9, 23.9, and 66.6 ng/ml after 0.1, 0.33, 1.0, 3.3, and 10 micrograms/kg hpGRF-40, respectively. Serum GH responses after insulin-induced hypoglycemia were compared to GH responses after hpGRF-40. Comparable peak GH stimulation occurred with both provocative tests. Mean +/- SEM peak GH was 20.2 +/- 1.0 ng/ml after insulin and 20.9 +/- 3.2 after hpGRF-40 treatment. hpGRF-40 selectively stimulates GH release in normal men over a dose range of 0.1-10 micrograms/kg and is an effective probe to investigate the dynamics of GH release.

Adult↗

Stimulation of growth hormone (GH) and somatomedin C in idiopathic GH-deficient subjects by intermittent pulsatile administration of synthetic human pancreatic tumor GH-releasing factor.

After initial challenges with vehicle alone and then 10 micrograms/kg human pancreatic tumor GH-releasing factor (hpGRF)-40, six adult subjects who had presented in childhood with idiopathic GH deficiency were given 0.33 micrograms/kg hpGRF-40, iv, every 3 h for 5 days. Serum GH levels were monitored daily for 90 min after the 0800 h doses of 0.33 micrograms/kg hpGRF-40, and serum somatomedin C was measured at 0800 and 2000 h. In addition, plasma levels of cholesterol, high density lipoprotein cholesterol, and triglycerides were measured daily at 0800 h. Three hours after the last 0.33 micrograms/kg dose, all subjects were rechallenged with 10 micrograms/kg hpGRF-40. In response to the initial 10 micrograms/kg challenge with hpGRF-40, and although serum GH levels rose in two of six subjects, the mean maximum GH level achieved was no different from that after treatment with vehicle alone. Within 12 h after initiation of the intermittent administration of hpGRF-40, mean +/- SEM serum somatomedin C had risen by 0.1 +/- 0.05 U/ml, and at the end of the 5-day period, had increased from 0.24 +/- 0.07 to 0.78 +/- 0.32 U/ml. In response to the second challenge with 10 micrograms/kg hpGRF-40, serum GH levels rose in three of the four subjects who initially failed to respond or had a less than 1 ng/ml GH response. The increase in serum GH was greater in one of the two subjects who had responded to the first dose. In addition, unlike the first dose, the mean maximal serum GH level achieved in response to the second 10 micrograms/kg dose of hpGRF-40 was higher than that in response to vehicle (P = 0.031). Although there was no statistically significant change during the 5-day period, in plasma cholesterol, high density lipoprotein cholesterol, or triglycerides, the latter exhibited a trend toward increased levels. Our preliminary data show that 5 days of intermittent hpGRF-40 administration augment GH secretion in some adults with GH deficiency, suggesting that somatotropes are present in idiopathic GH deficiency and may be primed by hpGRF-40. The rise in serum somatomedin C to normal levels after multiple injections of hpGRF-40 is encouraging, since circulating levels of somatomedin C may be more important than the increase in immunoreactive GH levels as an index of response for induction of linear growth. The demonstration of biological effects of hpGRF-40 in all six subjects without any serious adverse effects suggests that hpGRF-40 has promise in the treatment of GH deficiency.

Adult↗

Effects of human pancreatic growth hormone-releasing factor-40 on serum growth hormone, prolactin, luteinizing hormone, follicle-stimulating hormone, and somatomedin-C concentrations in normal women throughout the menstrual cycle.

Human pancreatic tumor GH-releasing factor-40 (hpGRF-40) selectively stimulates GH secretion in normal men and in some adults with GH deficiency. To study its effects in women, we administered hpGRF-40 (3.33 micrograms/kg) or an equivalent volume of vehicle as an iv bolus at 0900 h to 10 normal women during the early follicular, late follicular, and midluteal phases of the menstrual cycle. Serum concentrations of GH, PRL, LH, and FSH were measured at intervals between 0800-1100 h. Serum somatomedin-C concentrations were measured before and 24 h after the administration of vehicle of hpGRF-40. Within 1-3 min after the injection of hpGRF-40 all women described warmth localized to the head and neck and exhibited facial flushing. No changes in pulse rate or blood pressure were noted. When expressed as change from baseline and compared to control values, peak levels of serum GH (nanograms per ml; mean +/- SEM) were higher after hpGRF-40 treatment during the early follicular (5.4 +/- 3.2 vs. 34.9 +/- 8.3; control vs. test day; P = 0.011), late follicular (5.6 +/- 1.5 vs. 25.2 +/- 6.8; P = 0.014), and luteal (0.8 +/- 1.0 vs. 32.7 +/- 12.8; P = 0.033) phases of the menstrual cycle. Similarly, integrated serum GH levels (nanograms per ml/h) were higher after hpGRF-40 administration during the early follicular (0.72 vs. 16.1; P = 0.011), late follicular (0.83 vs. 9.9; P = 0.037), and luteal (-1.54 vs. 17.0; P = 0.036) phases of the cycle. When the increases in serum GH after hpGRF-40 treatment were compared among the phases of the menstrual cycle, however, no differences were found. Serum somatomedin-C values 24 h after hpGRF-40 treatment were higher than those 24 h after vehicle at all stages of the menstrual cycle. hpGRF-40 did not stimulate the release of PRL, LH, or FSH. We conclude that hpGRF-40 stimulates the release of GH, but that in response to the dose used, hpGRF-40-stimulated GH release does not vary during the menstrual cycle.

Adult↗

Who manages the postoperative cardiac patient?

Information on the role of the intensivist in postoperative cardiovascular patient care was obtained from a national survey of cardiac surgeons. The cardiac surgeon today retains overall responsibility for patient care. However, when intensivists are present, they significantly reduce the involvement of the cardiac surgeon in most aspects of patient care, particular ventilatory support. Intensivists are less likely to practice in nonteaching hospitals and less likely to be present in those cardiac surgical units that are not combined with other services. Because of the preponderance of intensivists in training programs, the surgical resident's role in patient care may be reduced in the future.

Cardiac Surgical Procedures↗