Quantitative analysis of contrasuppressor T lymphocytes in leprosy; induction of Ia antigens with gamma interferon

Lepromatous leprosy is characterized by immune anergy and abnormal suppressor T-cell function. Contrasuppressor cells are a subset of CD8+, vicia villosa-adherent T lymphocytes. T-contrasuppressor (Tcs) cells act on T-helper cells to cause them to become unresponsive to the action of T-suppressor cells. In 8 lepromatous (LL) and 7 tuberculoid (TT) patients, and 6 healthy contacts we studied the percent of the following lymphocyte subsets: CD3+, CD4+, CD8+, Ia+, vicia villosa+ (VV+), CD8, VV+, VV, Ia+, and Ia, Tac+. This was done in baseline status as well as post-stimulation with recombinant gamma interferon (rIFN-gamma). We found that peripheral blood mononuclear cells from LL and TT patients and controls exhibit a similar number of putative contrasuppressor lymphocytes (CD8, VV+ cells). However, in the contrasuppressor subset from LL patients we found a low percent of Ia+ (p less than 0.05 compared to controls or TT). In the three groups studied, the rIFN-gamma enhanced the percent of Ia+ lymphocytes in the CD8, VV+ cell subpopulation. However, the CD8, VV+ lymphocytes from LL patients, despite the effect of rIFN-gamma, continue to have a low percent of Ia+ cells (p less than 0.05 compared to controls or TT). These findings suggest that LL patients might have abnormalities in the contrasuppressor immune circuit. Future functional studies on the role of Tcs cells in the anergy seen in LL will be required in order to define the apparent dysfunction occurring in this disease.     

Intimal hyperplasia and coronary flow reserve after heart transplantation: association with big endothelin-1

BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation.     

Time-dependent effects of ovarian steroids on tyrosine hydroxylase activity in the limbic forebrain of female rats

Summary In this work, we have studied the time-course of the effects of pharmacological administration of ovarian steroids on tyrosine hydroxylase (TH) activity in the limbic forebrain of ovariectomized rats. Administration of estradiol produced a late decrease in TH activity. This effect was found 24 hours after the last steroid injection, disappearing at 32 hours. It was antagonized by progesterone, since a single injection of this steroid to estradiol-pretreated rats reversed to control values the estradiol-induced decrease. Nevertheless, the administration of progesterone after estradiol treatment caused a short-time decrease in the limbic activity of TH, which was observed 4 hours after the last steroid injection, disappearing subsequently. On the other hand, the administration of progesterone alone produced a biphasic effect, with a reduction at 24 hours, followed by an increase at 32 hours. These effects were only observed in the animals non-treated with estradiol, disappearing with a previous treatment with estrogens. Hence, it can be concluded that both ovarian steroids may affect the limbic TH activity. Thus, estradiol produced a late inhibitory effect on the activity of this enzyme, which was antagonized by progesterone. Administration of the last one to estradiol-treated rats produced a short-time inhibitory effect, whereas its administration to non-treated rats produced a late biphasic effect (inhibition followed by stimulation), which was not observed in estradiol-treated rats.     

Melatonin modifies the spontaneous multiunit activity recorded in several brain nuclei of freely behaving rats.

Melatonin, a pineal hormone, released photoperiodically, was administered systemically in rats, previously implanted with semimicroelectrodes into six different brain structures. The multiunit electrical activity of these structures was recorded for 10 min before and 60 min after melatonin administration in unanesthetized, freely moving rats. Different melatonin doses (100, 200, 500, and 1000 micrograms/kg) produced changes in the electrical activity of all tested structures. However, amygdala, rostral hypothalamus and mesencephalic reticular formation showed the most important changes. The main effect induced by melatonin was a dose-related decrease of the spontaneous electrical activity. The significance of these effects is discussed within the context of the behavioral and endocrinological effects of melatonin.     

Leading etiologic factors in periventricular bleeding and periventricular leukomalacia

Prenatal, intrapartum and postnatal factors were investigated in less than 32 gestational age preterm infants known to have periventricular haemorrhage or periventricular leukomalacia. The diagnoses were established on cranial ultrasonography and/or autopsy. Factors associated with periventricular haemorrhage were: postnatal severe hypercapnia, acidosis and hypoxia. In the periventricular leukomalacia group the incidence of antepartum and intrapartum hypoxia and/or ischaemia (antepartum haemorrhage) were significantly higher than in the control group.     

Cytophotometric investigations on atypical epithelial cells of the human seminal vesicle

Normal seminal vesicles were studied histologically in 80, and by Feulgen’s cytophotometric method in 10 autopsied cases (males, 44–82 years of age). In every case large, hyperchromatic nuclei were found. By cytophotometry euploid polyploid atypia was also shown in every case, which is characteristic of benign hormonal dysplasia.