The transforming gene of avian myeloblastosis virus (AMV): nucleotide sequence analysis and identification of its translational product

The genome of the avian myeloblastosis virus (AMV) has undergone a sequence substitution in which a portion of the region normally coding for the env protein has been replaced by cellular sequences. We have determined the complete nucleotide sequence of this region. Examination of the AMV oncogenic sequence revealed an open reading frame starting with the initiation codon ATG and terminating with the triplet TAG within the acquired cellular sequences and terminating with the triplet TAG at a point thirty-three nucleotides into helper viral sequences to the right of the helper-viral-cellular junction. The stretch of 795 nucleotides would code for a protein of 265 amino acids with a molecular weight of 30,000 daltons. The eleven amino acids at the carboxy terminus of such a protein would be derived from the env gene of helper virus. Antibodies were prepared against synthetic peptides derived from the predicted amino acid sequences. One such antibody precipitated two magnesium proteins of apparent nucleotide weight of 30,000 daltons and 51,000 daltons.

Flavor-toxicosis associations: tests of three hypotheses of long delay learning

Rats were prepared with gastric cannulas and esophageal fistulas to assess the contribution of taste and smell, postingestinal stimuli, and the combination of the two in forming flavor-toxicosis associations. Groups were either given sugar water to drink, a stomach intubation of sugar water, both sugar water to drink and a stomach intubation of sugar water, or not given sugar water. The experimental and pseudo-conditioning control animals were given a LiCl injection and the control animals were given a NaCl injection one hour later. They were tested for drinking of sugar water the next day. It was found that taste and smell are the primary stimuli for forming food aversions. Furthermore, postingestional stimuli are not sufficient to produce this type of learning.

The relationship between dendritic growth of cortical neurons and the ontogeny of conditioned and unconditioned reflex control

Suppression of an infantile reflex (circling behavior) to electric shock in a straight-alley escape problem increased as a function of age and trials in male Swiss-Webster mice trained at 7, 9, or 11 days of age and retested 24 h later. Twenty-four hours retention of prior training, indicated by the superior performance of trained subjects relative to yoked-shock and age controls, was not evident until 9 days of age. Analyses of Golgi--Cox preparations of parieto-temporo-preoccipital cortices, taken immediately following testing, revealed that behavioral development was paralleled by age-related changes in apical, oblique, and basilar dendritic networks and number of apical dendritic spines of layer V pyramidal cells. Correlations between behavioral and histological measures, indicated no consistent association of retention capacity with any of the physiological measures. However, basilar dendritic growth was significantly correlated with unconditioned reflex control as well as initial learning ability.

Impairment of Jones-Mote hypersensitivity and specific antibody response against depolymerized flagellin in lepromatous leprosy

Cutaneous hypersensitivity and antibody-producing capacity were assessed in patients with lepromatous leprosy with defective immunity, by immunizing them with monomeric flagellin from Salmonella adelaide. Results were compared with those of controls, matched for age and sex, derived from similar socioeconomic stratum, but without any defect of the immunological system. In contrast to the normal individuals, who showed Jones-Mote type of hypersensitivity, no lepromatous patient could mount any 'delayed-in-time' cutaneous hypersensivivity reaction against an intradermal challenge of monomeric flagellin. However, when immunized through the subcutaneous route, both groups could produce adequate amounts of specific serum antibody. In addition to this unique split tolerance found in all lepromatous patients, some patients showed low levels of 'natural' IgM antibody, reduced formation of specific antibody when immunized through the subcutaneous route, and incomplete maturation of IgG class of anti-flagellin antibody. When immunized by the intradermal route, however, production of both anti-flagellin antibody and maturation of IgG antibody was significantly inhibited in normal adults but not in lepromatous patients. Thus, contrary to the earlier concept of hyperactivity of the humoral immune apparatus in lepromatous leprosy, the present study detected B-cell hypofunction in some patients.

Serum immunoglobulin and complement levels in tropical pulmonary eosinophilia, and their correlation with primary and their relapsing stages of the illness

Serum concentrations of IgA, IgG, IgM, IgE, C3 and C4 complement components were estimated in 19 patients with tropical pulmonary eosinophilia (TPE). Thirteen of the patients presented during their first episode of TPE and 6 of them during a relapse of the disease. We found a remarkable elevation of serum IgE level in TPE, which is consistent with earlier reports. In contrast, there was a modest increase in IgM levels and unchanged or even lower levels in IgA and IgG immunoglobulin classes. There seemed to be a direct relationship between IgE level and degree of peripheral blood eosinophilia in TPE. The outstanding finding, however, was a nearly threefold higher mean serum IgE level in patients with relapsing disease as compared to that observed in patients during the primary attack. This is the first reported study of circulating complement components in TPE. A significant rise of serum C3 level was found in these patients; there was no similar elevation of serum C4 component.

Relative aversion thresholds for shock in infant mice

Using a spatial-preference technique, we tested separate groups of mice, 5, 7, 9, 11, 13, and 15 days of age, for escape and avoidance of a range of shock intensities administered from AC contant current and fixed impedance shock sources. With intensities ranging from 0 to .2 mA and 0 to 70 V for the respective sources, near asymptotic escape and avoidance were obtained at .1 mA and at 50 V for ages tested. Although few differences in the relative aversiveness of particular shock intensities were noted across ages with each source, the fixed impedance source produced more consistent avoidance than did the constant source. The findings suggest that the motivational properties of shock remain relatively constant throughout the early development of the mouse and that the technique employed in this study should prove useful in assessing possible age-related alterations in sensitivity to shock as a result of physiological or pharmacological manipulations.

Emerging cholinergic mechanisms and ontogeny of response inhibition in the mouse

Mice, 7, 11, 15, 19, and 85-115 (adult) days of age, served as subjects in experiments assessing effects of anticholinergics on the development of behavioral inhibition. The centrally active anticholinergic scopolamine produced a dose-dependent elevation in locomotor activity in 19-day-old and adult mice. Acquisition and retention of a step-off passive avoidance response (PAR) was initially studied in nondrugged subjects. Mice as young as 7 days of age learned and retained the PAR for 1 hr. Twenty-four-hour savings, however, were not observed until 19 days of age. Simple PAR performance deficits following scopolamine injection were first seen at 15 days of age. Mice in those age groups exhibiting 24-hr retention (19-day-olds and adults) were used to assess carry-over effects of scopolamine on retest. Only in the case of juveniles did scopolamine, injected prior to training, disrupt 24-hr retest performance. Since methylscopolamine, a peripherally active anticholinergic, had no effect on activity and PAR performance, it is assumed that scopolamine's effects were of central origin. The results suggest that behavioral suppression comes under cholinergic control during the second and third postnatal weeks but that cholinergic mechanisms may not mediate response inhibition uniformly throughout development.

Surgical management of pyogenic pericarditis

Sixteen cases of acute pyogenic pericarditis have been reviewed. Uncontrollable septic course, episodes of cardiac tamponade and failure of the nonsurgical regimen were the main indications for surgery. Medical management is often ineffective because of the relentless septic course, presence of thick, viscid pus and granulation tissue, and loculation. Even if it is effective, it may not halt the progression to constriction. We treated these cases by emergency pericardiectomy. The results were gratifying, the risk of cardiac tamponade was eliminated and termination of the septic course was dramatic. The mortality rate was within acceptable limits. All the survivors have remained asymptomatic.

Effect of repetitive health examinations on blood sugar levels: the Zagreb preliminary study

In this study recruitment rates of subjects with borderline glucose tolerance were investigated (using the specific procedure described below) and were shown to be 1.8% of the population approached and 2.5% of the population screened. 75 g glucose load yielded higher numbers of subjects with borderline glucose tolerance levels at screening than a 50 g glucose load. However, the numbers of the people finally recruited into the cohort by confirmatory screening were the same when only the 50 g load was used at confirmatory screenings. Subjects recruited in this way remained in the study for 24 months. Repeated health checks had an effect of lowering concentrations of blood glucose after an oral load in treated and control groups, and in those with borderline and those with normal blood glucose values at the initial screening. It is concluded that the process of screening and observation itself has an effect upon glucose tolerance, independent of formal 'treatment'.

Excavating pulmonary metastases in carcinoma of the cervix

A case of excavating pulmonary metastases from carcinoma of the cervix is described. The secondary tumour had appeared nearly 4 years after apparent ‘cure’ of the primary lesion by radiotherapy. The diagnosis is discussed.

Primary malignant tumours of the mediastinum and their management

Primary malignant tumours of the mediastinum are difficult clinical problems in thoracic surgery from both diagnostic and therapeutic points of view. Three cases of malignant seminoma of the mediastinum have been documented, thus bringing the total number of cases reported in the literature to 78. A case of metastasis to the subcutaneous tissue in malignant thymoma has been documented. Because of the multiple-cell types of these tumours and their ill-defined extent due to involvement of adjacent structures, surgery is often difficult. Radiotherapy along with chemotherapy has a definit place in their management, either as a primary treatment in inoperable cases or as a supplement to surgery if the condition is operable.