Possible nonspecific immunopotentiation by 2,4-dinitrochlorobenzene sensitization in patients with Hodgkin's disease.

Various immunological parameters were evaluated in untreated Hodgkin's patients before and after sensitization with dinitrochlorobenzene (DNCB). The ratio (r) of these parameters after/before DNCB sensitization for patients and second/first samples in the controls were calculated. There were significantly more patients in the r greater than 1.1 group for PHA and Con A responses and for peripheral blood T cell percentages. These data suggest that DNCB sensitization may have a nonspecific immunopotentiation effect.     

Focal ependymal differentiation in choroid plexus papillomas

Summary Choroid plexus papillomas are usually easily distinguishable from papillary ependymomas by their delicate fibrovascular stroma and their cytologic similarity to normal choroid plexus epithelium. Exceptionally, however, examples are met which give rise to diagnostic difficulty. We therefore tested 22 choroid plexus papillomas for the presence of glial fibrillary acidic (GFA) protein using the immunoperoxidase technique. Positivity for the protein was found focally in epithelial tumor cells in nine of the 22 papillomas. All were in adults ranging from 19–66 years of age. Eight of the nine tumors originated in the 4th ventricle or from one of its lateral recesses. In six papillomas showing GFA protein in the cells, intracellular fibrils were found in a small number of elongated epithelial cells with the PTAH and/or Masson trichrome stains; in all these six cases, the GFA protein-positive cells were considerably more numerous than cells containing fibrils. Normal choroid plexus epithelium lacks GFA protein, but pathologically altered ependymal cells are often GFA protein-positive. Our findings therefore suggest that focal divergent glial (presumably ependymal) differentiation may be expressed in neoplastic choroid plexus epithelium, consistent with the origin of this epithelium from primitive neuroepithelial (ventricular) cells.This work was supported in part by Research Grant CA-11689 from the National Cancer Institute, USPHS     

Mycobacterium intracellulare infection of the shoulder and spine in a patient with steroid-treated systemic lupus erythematosus

Atypical mycobacterial infections of bone are rare. A patient with systemic lupus erythematosus treated with steroids developed an M. intracellulare infection of the shoulder and spine. These infections are insidious and diagnosis is difficult. Marked involvement of one joint, large effusion, or aspirated small synovial fragments suggest an atypical tuberculous joint infection.     

Vascular response to short-term systemic hypoxia, hypercapnia, and asphyxia in the cat.

Acute systemic hypoxia, hypercapnia, or asphyxia was produced in ketamine-anesthetized, paralyzed cats by ventilating them for 2-4 min with appropriate gas mixtures. A sustained rise in arterial pressure occurred in all cases. Vascular responses to hypoxia (7% O2, 10% 02, or 14% O2) included muscle constriction, cutaneous (hindpaw) dilatation (no change with 14% O2), renal constriction (unchanged flow), and unchanged intestinal resistance. Asphyxia (hypoxia + 10% CO2) produced a similar pattern, except that intestinal dilatation occurred. Hypercapnia (10% CO2 + 21% O2) produced muscle constriction, renal constriction (unchanged flow), intestinal dilatation, and no change in cutaneous resistance. Intestinal dilatation seemed in all cases a response to elevated CO2 only. Hypercapnia augmented the effects of hypoxia in skin and skeletal muscle. The variation of responses in different vascular beds suggests a patterning of sympathetic discharge, and varying responsivity to local and humoral factors.     

The Detection of Chagas'' Disease:

Abstract. A rapid slide test for the detection of Chagas' antibodies is described. It uses tanned human red cells coated with an aqueous extract of T. cruzi cultures. The sensitivity and specificity of this new method are compared to those of the classical hemagglutination reaction and the C fixation and are found to be just as adequate. The method can be used in any blood bank and requires no special skills or instruments.     

Modifications of the "alarm" pattern by nicotine

The effect of nicotine on the behavioral and autonomic response pattern, “alarm”, evoked in awake cats implanted with recording devices by stimulation of stereotaxically oriented hypothalamic electrodes was studied. Before stimulation, the lowest effective intravenous infusion rate of nicotine (10 μg/min) induced EEG desynchronization, increased gastrointestinal motility and decreased heart rate. As the infusion rate was raised to 50 {mg/min}, the arterial pressure increased, and moderate iliac and mesenteric vasoconstriction occurred. The effects of nicotine on the response to short hypothalamic stimulation (100–500 msec) were: less tachycardia, a marked post-stimulus enhancement of gastrointestinal motility, a decreased threshold for growling, and an increased number of somatic responses (head turn). The effects of nicotine on the response to long hypothalamic stimulation (1–5 sec) were, in addition, a more marked pressor response and a reduction of the iliac vasodilatation.     

Brain stimulation and morphine reward deficits in dopamine D2 receptor-deficient mice

Rationale The rewarding effects of lateral hypothalamic brain stimulation, various natural rewards, and several drugs of abuse are attenuated by D1 or D2 dopamine receptor (D1R or D2R) antagonists. Much of the evidence for dopaminergic involvement in rewards is based on pharmacological agents with limited or “relative” selectivity for dopamine receptor subtypes. Genetically engineered animal models provide a complementary approach to pharmacological investigations. Objectives In the present study, we explored the contribution of dopamine D2Rs to (1) brain stimulation reward (BSR) and (2) the potentiation of this behavior by morphine and amphetamine using D2R-deficient mice. Methods Wild-type (D2Rwt), heterozygous (D2Rhet), and D2R knockout (D2Rko) mice were trained to turn a wheel for rewarding brain stimulation. Once equivalent rate–frequency curves were established, morphine-induced (0, 1.0, 3.0, and 5.6 mg/kg s.c.) and amphetamine-induced (0, 1.0, 2.0, and 4.0 mg/kg i.p.) potentiations of BSR were determined. Results The D2Rko mice required approximately 50% more stimulation than the D2Rwt mice did. With the equi-rewarding levels of stimulation current, amphetamine potentiated BSR equally across the three genotypes. In contrast, morphine potentiated rewarding stimulation in the D2Rwt, had no effect in the D2Rhet, and antagonized rewarding stimulation in the D2Rko mice. Conclusions D2R elimination decreases, but does not eliminate, the rewarding effects of lateral hypothalamic stimulation. After compensation for this deficit, amphetamine continues to potentiate BSR, while morphine does not.