Responses of growth hormone (GH) and somatomedin-C to GH-releasing hormone in healthy aging men.

Although controversy exists regarding the effects of aging on GH secretory responses to indirect stimulation, in the only prior study of GH-releasing hormone (GHRH)-mediated GH secretion decreased GH responsivity occurred in healthy men after age 40 yr. We measured serum GH before and up to 180 min after and somatomedin-C (SM-C) levels before and 24 h after single morning bolus iv injections of GHRH-(1-44)-NH2 (1 microgram/kg) in 50 healthy fasted men, aged 21-86 yr, from the Baltimore Longitudinal Study of Aging. Only subjects with a body mass index (BMI; kilograms per m2) between 20.

The interaction of interferon with the immune response.

Interferon (IFN) is a component of the immune response and influences immune responses as demonstrated by in vitro experimentation. In this review these complementary aspects of IFN's interaction with the immune response are discussed. Of chief interest is IFN-gamma ('immune' IFN) but IFNs-alpha and -beta are also considered.

In vivo pretreatment with human chorionic gonadotropin fails to reverse the dysfunction of isolated Leydig cells from chronically uremic rats.

In order to further investigate the previously reported hypogonadal state of chronically uremic rats, we examined the effects of in vivo pretreatment with human chorionic gonadotropin (hCG) on in vivo and in vitro Leydig cell function, comparing paired intact rats with rats made chronically uremic by 5/6 nephrectomy. The in vitro testosterone (T) secretory responses to varying concentrations of hCG or dibutyryl cAMP and the number of gonadotropin receptors were determined following hemicastration. The rats were then treated with hCG for 3 days and the remaining testes were removed and studied as before.

The effect of interferon treatment of targets on susceptibility to cytotoxic T-lymphocyte killing: augmentation of allogeneic killing and virus-specific killing relative to viral antigen expression.

The effect on CTL lysis of treatment of CTL targets with IFNs has been investigated. Treatment of targets for alloreactive CTL with either IFN-alpha beta or IFN-gamma markedly augmented cytotoxicity. Cold competition experiments implied that CTL recognized the same target structure on both untreated and IFN-treated cells.

Decreased in vitro secretion of LH, FSH, and free alpha-subunits by pituitary cells from old male rats.

Various in vivo and in vitro pituitary-Leydig cell functions were examined in mature (5-8 mo) vs. old (22-25 mo) male Wistar rats. Old rats exhibited decreased serum concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) (P less than 0.

Improved right ventricular function following late pulmonary valve replacement for residual pulmonary insufficiency or stenosis.

Residual severe pulmonary insufficiency or stenosis may result in significant myocardial dysfunction late after repair of tetralogy of Fallot. Although pulmonary valve replacement has been advocated for selected patients, objective improvement in right ventricular function has been difficult to demonstrate. We undertook pulmonary valve replacement in 11 patients to treat residual insufficiency (n = 8) or stenosis (n = 3) and evaluated them before and after operation by radionuclide ventriculography and M-mode echocardiography.

Specific 5' and 3' regions of the mu-chain gene are undermethylated at distinct stages of B-cell differentiation.

The mu-chain gene is expressed differently in successive stages of B-lymphocyte development. The heavy chain product appears as a cytoplasmic constituent in pre-B-cells, as part of the IgM receptor in maturing B cells, and as a component in the pentamer IgM antibody synthesized and secreted by the antigen-stimulated cell. We have used the methylation of CpG sequences as an assay system to define the chromatin changes associated with different expression of the mu-chain.

Unequal cardiac care for children with Down's syndrome.

We reviewed the course of all 36 new patients with complete atrioventricular canal defect (CAVC) seen in a regional center from 1977 through 1982. Of this group of 36 patients, 28 had Down's syndrome. The eight children without Down's syndrome were all referred before 1 year of age.

Ventricular arrhythmias and mitral valve prolapse in childhood.

Although ventricular arrhythmias are well described in adults with mitral valve prolapse, this association remains controversial in children. To assess the incidence of ventricular premature complexes (VPCs), 103 consecutive children with mitral valve (MV) prolapse confirmed by echocardiography were evaluated prospectively by treadmill exercise and ambulatory ECG. A group of 50 normal children with clinical, ECG, or echocardiographic evidence of heart disease who had undergone treadmill exercise and ambulatory ECG served as controls.

Ig RNA expression in normal B cells stimulated with anti-IgM antibody and T cell-derived growth and differentiation factors.

An increase in mRNA encoding the secretory form of the mu heavy (H) chain (mus) and in the ratio of mus mRNA to the mRNA encoding the membrane form of the microH chain (micron) occurs in normal B cells stimulated with anti-IgM and BSF-p1 together with the two B cell differentiation factors B15-TRF and EL-TRF. Stimulation of cells with anti-IgM and BSF-p1 with either B15- or EL-TRF causes no change in mus levels or mus/micron ratios. The requirements for induction of high rate IgM synthesis in normal B cells stimulated with anti-IgM were precisely the same as those required for elevation of mus, mRNA levels and for increase in mus/micron mRNA ratios.

Excess in vitro prolactin secretion by pituitary cells from ovariectomized old rats.

Various in vivo and in vitro pituitary lactotropic and gonadotropic functions were measured in mature (6-7 mo, normally cycling) and old (24 mo, constant diestrus) female Wistar rats. Serum prolactin (PRL) levels were higher (P less than 0.001), whereas luteinizing hormone (LH) values were similar (P greater than 0.

Results with the two-patch technique for repair of complete atrioventricular septal defect.

From May, 1982, to September, 1983, 9 patients underwent repair of complete AV septal defect. They ranged in age from 11 months to 48 months and in weight from 5.3 kg to 16.

Pulmonary hemodynamics and maintenance of palliation following polytetrafluoroethylene shunts for cyanotic congenital heart disease.

Subclavian-to-pulmonary artery anastomoses with interposition polytetrafluoroethylene (PTFE) conduits provide excellent early palliation for many forms of cyanotic heart disease. It is important to assess whether patients with this condition maintain adequate arterial oxygenation without developing pulmonary artery distortion or hypertension. From October, 1980, to December, 1982, 29 PTFE shunts were performed.

Ventricular arrhythmias and biventricular dysfunction after repair of tetralogy of Fallot.

To test the hypothesis that subclinical levels of ventricular dysfunction contribute to the development of ventricular arrhythmias after repair of tetralogy of Fallot, 38 postoperative patients were studied by radionuclide ventriculography and M-mode echocardiography. Eighteen patients (group I) had Lown grade 2 or greater ventricular arrhythmias on ambulatory electrocardiography or treadmill exercise, or both; 20 patients (group II) had no documented ventricular arrhythmias. Radionuclide ventriculograms were performed using technetium -99m-labeled red cells; ejection fractions were derived by computer from multigated images, with normal values being 45% for the right ventricle and 55% for the left ventricle.

Gamma interferon production and cytotoxicity of spleen cells from mice infected with Semliki Forest virus.

Interferon (IFN) production by spleen cells from normal mice, mice acutely infected with Semliki Forest virus (SFV) or mice immune to SFV was measured after stimulation in vitro with either infectious or inactivated SFV. All three classes of spleen cells made IFN-alpha beta in response to infectious SFV. Spleen cells taken from mice late, but not early, after infection, or from immune mice, made IFN-gamma in response to inactivated SFV.

In vivo chorionic gonadotropin administration reverses the testosterone secretory defect of Leydig cells from old rats.

Old male rats have decreased serum testosterone, luteinizing hormone (LH), follicle -stimulating hormone (FSH), Leydig cell testosterone secretory responsiveness to chorionic gonadotropin (hCG), and gonadotropin binding capacity. Although prolonged in vivo hCG administration restores serum testosterone, in vitro hCG exposure of Leydig cells does not reverse their age-related hyporesponsiveness. To explore this discrepancy, we studied Leydig cell function before and after hCG administration in vivo (treatment).

Production of type I (alpha/beta) interferon after virus infection of cloned, alloantigen-sensitized mouse T lymphocytes.

Mouse T lymphocytes sensitized to alloantigens were cloned by limiting dilution in the presence of interleukin 2. Clones were tested for surface markers Thy-1, Lyt-1 and Lyt-2, and for cytotoxic function. Production of interferon (IFN) by clones either (a) stimulated with allogeneic cells; (b) activated with concanavalin A (Con A); or (c) infected with Semliki Forest virus or Newcastle disease virus were assayed.

Pituitary-thyroid hormone economy in healthy aging men: basal indices of thyroid function and thyrotropin responses to constant infusions of thyrotropin releasing hormone.

In order to assess the effects of aging, as distinct from those of thyroid disease or extrathyroidal illness, on certain indices of thyroid function, we studied 74 healthy, ambulatory men recruited from the Baltimore Longitudinal Study on Aging. We determined basal serum values of T4, T3, rT3, thyroxine-binding globulin (TBG), and T3 resin uptake (T3RU) and calculated the free T4 index (FT4I = T4 X T3RU/100), free T3 index (FT3I = T3 X T3RU/100), and T4/TBG ratio for each subject. We used an ultrasensitive RIA to measure variations in basal concentrations of TSH within the normal range.

Subclavian-pulmonary artery shunts with polytetrafluorethylene interposition grafts.

Systemic-pulmonary artery shunts remain an important treatment in cyanotic patients. Central shunts continue to pose early and late problems when standard Blalock-Taussig shunts are not possible. Twenty patients underwent subclavian-pulmonary artery shunt procedures with polytetrafluoroethylene (PTFE) prostheses between October, 1980, and August, 1982.

Two-dimensional echocardiographic assessment of infective endocarditis in children.

We examined 11 children with infective endocarditis initially and serially by two-dimensional echocardiography. Nine (82%) of the 11 patients had echocardiographic findings at initial examination compatible with infective endocarditis. These results provided strong evidence in support of the diagnosis before bacteriologic confirmation was available.

The influence of pulmonary insufficiency on ventricular function following repair of tetralogy of Fallot. Evaluation using radionuclide ventriculography.

Long-standing pulmonary insufficiency after repair of tetralogy of Fallot may adversely affect ventricular function. We evaluated 20 patients at a mean of 9 years after repair by radionuclide ventriculography, 24 hour Holter monitoring, and M-mode echocardiography. The mean age at complete repair was 7.

Biological and psychological aspects of a case of Gilles de la Tourette's syndrome.

The case of a 12-year-old girl with Gilles de la Tourette's syndrome is presented, and the following factors are discussed: psychological aspects, urinary excretion of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and unconjugated amines, and CT scan findings. The most noticeable differences from normal controls seen in the urine studies were elevated levels of beta-phenylethylamine and the catecholamine metabolites normetanephrine, MHPG, and 3-methoxytyramine, and a decrease in 5-hydroxytryptamine. A CT scan revealed a slight increase in density in the caudate nuclei bilaterally; this was thought to be due to calcification.