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Biomedical subjects

D L Kaiser

Publications and source records attributed to D L Kaiser.

At least 127 records · Page 7Linked to original sources

Intranasal administration of human pancreatic tumor GH-releasing factor-40 stimulates GH release in normal men.

Human pancreatic tumor GH releasing factor-40 (hpGRF-40) selectively stimulates GH secretion in normal men and in some adult patients with GH deficiency. As the latter finding suggests that some children with GH deficiency may benefit from therapy with hpGRF-40 or an analogue, we investigated the effect of hpGRF-40 administered intranasally on GH release. Six normal men were given hpGRF-40 (30 ug/kg; test day) or an equivalent volume of vehicle alone (control day) at 0900 h. Immunoreactive GH was measured in serum obtained at intervals between 0800-1200 h. Mean (+/- SEM) integrated serum levels of GH (ng/ml/h) prior to and following administration of vehicle were not different (1.27 +/- 0.57 vs 0.87 +/- 0.28; p = 0.54). However, following hpGRF-40 administration, GH levels increased significantly (0.53 +/- 0.03 vs 2.88 +/- 0.75; p = 0.022). Peak levels of serum GH were detected within 30 min following hpGRF-40. Except for mild burning of the nasal mucosa reported by one subject, no side effects were noted. We conclude that, if hpGRF-40 or an analogue is shown to be useful in the treatment of some children with GH deficiency, the intranasal route of administration may be utilized and will be more acceptable for chronic therapy than intravenous, intramuscular, or subcutaneous injection.

Administration, Intranasal↗

Organ-specific autoantibodies in children with common endocrine diseases.

Sera from 438 children were examined for autoantibodies to thyroid microsomes, thyroglobulin, pancreatic islet cells, gastric parietal cells, and adrenocortical cells by indirect hemagglutination and immunofluorescence techniques. A modification of the indirect hemagglutination technique allowed specific detection of low titers of antithyroidal antibodies. The subjects included a control group (117) with no known autoimmune disease, and children with disorders of the thyroid (88), insulin-dependent diabetes mellitus (201), Turner's Syndrome (24), and Addison disease (8). A subject's age at the time of disease onset and the race and sex were correlated with the prevalence of autoantibodies. The coincidence of autoantibodies to components of the thyroid with autoantibodies to gastric parietal cells was increased in children with disorders of the thyroid (94%, 18/19) over that observed in diabetes (29%, 4/14), Turner syndrome (0%), or Addison disease (0%), perhaps indicating different genetic propensities for the development of parietal cell antibodies in these groups. Islet cell antibodies were not found in subjects with Turner syndrome, nor were they more prevalent in white or black subjects with diabetes. The incidence of organ-specific autoantibodies in individuals without overt clinical disease may reflect an altered immunologic state that will lead eventually to autoimmune disease. Islet cell antibodies decline in prevalence in diabetes, whereas thyroid antibodies in disorders of the thyroid do not; this may reflect differences in the pathogenesis of these common autoimmune endocrine disorders in children.

Addison Disease↗

Immunologic response of the prostate to bacteriuria and bacterial prostatitis. I. Immunoglobulin concentrations in prostatic fluid.

We investigated the impact of bacteriuria and bacterial prostatitis on the immunoglobulin content of prostatic fluid. Using an indirect solid-phase radioimmunoassay, we assayed samples of expressed prostatic secretion (EPS) from 20 men with no histories of bacteriuria and from 13 men with histories of culture proven bacteriuria for IgG, IgA and IgM concentrations. Five of the bacteriuric men had culture proven bacterial prostatitis. The concentrations of each immunoglobulin varied widely and were unrelated to age, race, history of urologic instrumentation, presence of benign prostatic hyperplasia, leukocyte content of EPS or EPS aerobic bacterial culture results. The mean concentration of IgG for samples from the bacteriuric patients, 44.3 mg/ml., was similar to that of the uninfected patients, 58.4 mg./dl. (p less than 0.5). The mean concentrations of IgA and IgM for samples from the bacteriuric patients, 89.2 and 1.44 mg./dl., respectively, were greater than those of the uninfected patients, 25.2 and 0.95 mg./dl., respectively. These differences, however, did not achieve statistical significance, p less than 0.025 and p less than 0.3, respectively. However, the mean ratio of IgA:IgG for samples from the bacteriuric patients, 1.67, was significantly greater than that of the uninfected patients, 0.34 (p less than 0.005). The fraction of IgA in the form of secretory IgA was greater than 60 per cent for samples obtained from both the uninfected and bacteriuric patients. These data suggest that bacteriuria is associated with increased secretion of IgA in the prostatic fluid.

Adult↗

The effects of oral iodized oil on intelligence, thyroid status, and somatic growth in school-age children from an area of endemic goiter.

One hundred goitrous school children received 475 mg iodized oil by mouth, while 100 controls received mineral oil, on a double-blind basis. On follow-up 22 months later the urinary iodine had increased and goiter size had decreased in both groups, more strikingly in the iodine-treated children. There were no consistent differences between the two treatment groups in rate of somatic growth or performance on the Stanford-Binet and Bender tests. Because of the complexities introduced by increases in urinary iodine in the controls, we compared goiter reduction with improvement in IQ score in all children, regardless of group, and found a significant relationship (p = 0.014), particularly in girls (p = 0.029). We conclude that oral iodized oil is an attractive alternative to its injection but we recommend an approximate doubling of the dose used here for more effective control. Also, while our data are not conclusive, they support the possibility that correction of iodine deficiency may improve mental performance in school age children, particularly girls.

Administration, Oral↗

Unremitting suppression of the postovariectomy rise in plasma LH by tumor-induced hyperprolactinemia.

The plasma LH response to ovariectomy was studied at different periods in the development of hyperprolactinemia in rats bearing the transplantable prolactin-secreting pituitary tumors 7315a or MtTW15. Rats were subcutaneously inoculated with tumor cells and ovariectomy was performed at 3 times during the subsequent growth of the solid tumor: (1) coincident with tumor cell implantation; (2) when solid tumors first became palpable, and (3) when solid tumors were large. The values for circulating prolactin and LH were serially determined following ovariectomy for 63, 35 and 28 days, respectively. In other studies, tumor cells were implanted into animals which had undergone ovariectomy 3 months earlier. In the presence of hyperprolactinemia caused by the prolactin secreting tumors, the plasma LH following ovariectomy was either reduced following an initial increase, prevented from increasing, or reduced from chronically elevated levels. Hyperprolactinemia of approximately 7-50 micrograms/ml caused marked suppression of LH secretion, while hyperprolactinemia in the range of 0.2-6 micrograms/ml resulted in significant but slower and lesser suppression of LH which did not reach noncastrate levels. The inhibitory effect of hyperprolactinemia on plasma LH after ovariectomy was persistent and unremitting for the duration of each experiment, and there was no tendency for suppressed LH to return to levels expected for the ovariectomized state. The model of hyperprolactinemia induced with transplantable prolactin-secreting tumors in the ovariectomized rat may prove to be valuable in understanding the mechanism of depression of gonadal function by hyperprolactinemia.

Animals↗

Chronic traumatic thoracic aneurysm. Influence of operative treatment on natural history: an analysis of reported cases, 1950-1980.

A total of 401 cases of chronic traumatic aneurysm reported during the past 30 years plus 12 cases from the University of Virginia Medical Center were analyzed. Forty-two percent of the patients developed signs or symptoms of aneurysm expansion within 5 years of injury: 85% within 20 years. Pain was the most frequently occurring sign or symptom, followed by serial enlargement on chest roentgenogram. Of the 60 patients who were followed without operative intervention, 20 died of their aortic lesions. For these patients, the combined risk of dying or developing signs or symptoms was 41% at 5 years. Over 300 patients underwent operative repair of the aneurysm. Operative mortality was 4.6%. Bleeding was the major cause of death as well as the most common major complication. When the survival probability of patients treated operatively was compared with that of patients treated nonoperatively, the operative group demonstrated a significantly higher survival probability.

Adolescent↗

Relation between surgical volume and incidence of postoperative wound infection.

We used a statewide program for the surveillance and reporting of infections acquired in the hospital to examine the relation between volume of surgery and the incidence of postoperative wound infection. Over a 29-month period 25,941 surgical procedures performed at 22 hospitals were studied. For all procedures studied, the mean number of operations performed was directly related to hospital size (number of beds). A highly significant inverse relation was found between the logarithm of the frequency of operation and the infection rate for appendectomy, herniorrhaphy, cholecystectomy, colon resection, and abdominal hysterectomy. (The relation was borderline [P = 0.055] for laminectomy and not significant for cesarean section.) Although these data clearly demonstrate higher morbidity in hospitals performing relatively little surgery, there are several possible explanations, and no conclusions for health policy can yet be drawn.

Data Collection↗

Insulin resistance in adipocytes from fed and fasted obese rats: dissociation of two insulin actions.

Adipocytes from 26-week-old Zucker rats (greater than 600 g) and controls of the same strain and age (greater than 400 g) served as models of insulin resistance and obesity. Adipocytes from fatty rats demonstrated insulin resistance of glucose metabolism and resistance to the antilipolytic effect of insulin which was not improved by fasting. Adipocytes from fatty rats were also resistant to the lipolytic action of norepinephrine. Control rats displayed insulin resistance of glucose metabolism and resistance to the antilipolytic effect of insulin. However, fasting for 6.5 days restored the antilipolytic action of insulin without affecting the insulin sensitivity of glucose metabolism. This dissociation of the responsiveness of insulin actions by fasting indicates that there may be at least two mechanisms of insulin resistance in the same cell.

Adipose Tissue↗

Thyroid cancer: some basic considerations.

From these data and data from the literature, our recommended treatment for well-differentiated cancer is as follows: For papillary cancer, resection should be adequate to encompass the entire tumor, which in most cases would be complete lobectomy and possibly isthmusectomy. Prophylactic neck dissection is of no value; therapeutic modified neck dissection should be done for stage II disease. Follicular cancer can be treated by lobectomy (for small lesions) or subtotal thyroidectomy. Although total or near-total thyroidectomy may be required in selected patients with large primary cancers or in those with extensive capsular invasion or extrathyroid extension, the number of cases indicating this is small. There were only a few such patients with large primaries requiring total thyroidectomy in this study. Total thyroidectomy is best avoided in most cases. considering the price of hypoparathyroidism and the lack of a significant improvement in survival compared with lesser ablative techniques. Postoperative ablation with iodine-131 did not improve survival in staged patients with papillary cancer (the number of patients with follicular cancer was too small for analysis). Postoperative thyroid suppression by exogenous thyroid hormone postoperatively appeared to improve survival. Although the data were not adequate for evaluation in follicular cancer, there seems to be no reason not to use this postoperatively in high risk patients with either papillary or follicular cancer.

Adenocarcinoma↗

Lung compliance and its transient elevations measured with pulse-flow method.

We describe a pulse-flow method of measuring static lung compliance (CL) that is sensitive to rapid transients in CL. CL is measured by blowing air at a constant flow into the mouth and lungs for 2 s and calculated by dividing airflow in 1/s by the change in transpulmonary pressure in CMH2O/s. Pulse and static inspiratory CL was measured in five normals, four obstructives, five obese, and two patients with pulmonary fibrosis, Pulse CL after tidal breathing was correlated with static CL measured after deep breaths (r = 0.96). Pulse CL after deep breaths was higher than pulse CL after tidal breathing (p less than 0.01) and then static CL after deep breaths (p less than 0.05). In all subjects the lower the forced expiratory volume in 1 s, expressed as a percentage of vital capacity (FEV1/FVC), the greater the increase in pulse CL after a deep breath will be (r = 0.93). After deep breaths pulse CL fell from maximum CL to base-line CL at a rate related to 1/t2 where t equals the time in seconds from the last deep breath. We conclude that the increase in CL after a deep breath is related to the degree of airway obstruction and that the subsequent fall in CL is related to 1/t2.

Adult↗

Ontogeny of blood pressure and the renin-angiotensin-aldosterone system. Sequential studies in the newborn lamb.

To test the hypothesis that the rise in arterial pressure occurring with maturation is due to an increase in the vascular responsiveness to angiotensin II, sequential cumulative doses of angiotensin II were infused intravenously into chronically catheterized newborn lambs maintained on a constant, weight-adjusted sodium intake from birth to 8 weeks of age. Basal mean arterial pressure correlated with both age and weight, but age was a stronger determinant of mean arterial pressure than was weight. No change in the mean arterial pressure response to angiotensin II occurred with maturation. Basal plasma renin activity and plasma aldosterone concentrations were low and did not change significantly with age. Therefore, in the newborn lamb in the sodium replete state, age is a better determinant of arterial pressure than is weight. However, an age-related change in vasoconstrictor responsiveness to angiotensin II does not occur and, therefore, cannot account for the rise in arterial pressure that is observed with maturation.

Aging↗

Dopaminergic mechanisms and luteinizing hormone (LH) secretion. II. Differential effects of dopamine and bromocriptine on LH release in normal women.

After our observation of the failure of bromocriptine to inhibit LH secretion in hyperprolactinemic women, we have investigated the effects of bromocriptine and dopamine (DA) on LH secretion in normal ovulatory women within 5 days of the midcycle LH peak. Both bromocriptine (2.5 mg, orally) and DA (4 micrograms/kg . min, iv) for 4 h lowered serum PRL levels by more than 80%. Bromocriptine was ineffective in suppressing LH secretion and, in fact, resulted in a slight but significant stimulation, while, in contrast, DA was effective in lowering circulating LH levels by approximately 30% and reducing spontaneous LH fluctuations. The dissociation of the effects of these two dopaminergic agents on LH secretion may be explained by the existence of multiple DA receptors. The slight stimulatory effect of bromocriptine might be due to a preferential presynaptic action of bromocriptine inhibiting endogenous DA secretion in the hypothalamus and thus reducing this catecholamine's tonic inhibitory influence on LH secretion.

Adult↗