Ambient temperature related sleep changes in rats neonatally treated with capsaicin

Ambient temperature related sleep changes in rats neonatally treated with capsaicin. PHYSIOL BEHAV 00(0) 000-000, 2004. The study was conducted on adult male Wistar rats, neonatally treated with capsaicin to destroy the peripheral warm receptors. The sleep-wakefulness was recorded for 5 h at an ambient temperature (T(amb)) of 18, 24, 30 and 33 degrees C on different days. The rectal temperatures (T(r)) of the rats were studied on exposure to 6 and 37 degrees C for 2 h to assess their thermoregulatory ability. The changes in the behavioral thermoregulation were assessed by noting the thermal preference of rats when they were placed in an environmental chamber with 3 interconnected compartments maintained at 24, 27 and 30 degrees C. Slow wave (SWS) and rapid eye movement (REM) sleep were decreased at 18 degrees C and increased at 30 degrees C, in control rats. There was a decrease in REM sleep and no change in SWS when T(amb) was raised from 30 to 33 degrees C. However, in neonatally capsaicin treated rats, sleep was increased even at 33 degrees C, though there was no significant change in sleep when T(amb) was increased from 18 to 24 degrees C. Capsaicin treated rats showed thermoregulatory deficiency at 37 degrees C but the thermal preference was unaltered in these rats. The results suggest that the central warm receptors can produce alteration in sleep at different T(amb), even in absence of peripheral warm receptors. The behavioral thermoregulation was unaffected in these rats, though their ability to defend the body temperature in warm environment was affected.     

Role of the lateral septal noradrenergic system in the elaboration of male sexual behavior in rats

The study was aimed at investigating the possible involvement of noradrenergic mechanisms in the lateral septum (LS) for elaboration of male sexual behavior in rats. In this study, norepinephrine (NE), yohimbine (YOH), isoproterenol (ISOP), propranolol (PROP), saline (SAL) and dimethyl sulfoxide (DMSO) were injected bilaterally in the LS in six different groups of sexually active male rats, and various components of sex behavior were recorded. The application of NE (3 microg) and alpha(2)-antagonist YOH (1 microg) produced a stimulation of most of the components of male sexual behavior, and there was increase in sexual arousal as well as performance. The microinfusion of nonspecific beta-agonist ISOP (2 microg) also produced a stimulation of copulatory behavior whereas beta-antagonist PROP (2 microg) produced an inhibition. The stimulation of male sexual behavior by YOH application at the LS could be due to an increased release of NE by its blocking effect on presynaptic alpha(2)-receptors. These results suggest that the noradrenergic system in the LS has stimulatory effect upon male sexual behavior, probably acting through beta-receptors.     

Arsenic trioxide in the treatment of newly diagnosed acute promyelocytic leukemia: a single center experience

Arsenic trioxide (As(2)O(3)) has been found effective in the treatment in the treatment of acute promyelocytic leukemia (APML). Most studies with As(2)O(3) involve patients with APML who have relapsed following standard therapy. Between January 1998 and July 2000, 14 patients were recruited for an ongoing trial of As(2)O(3) in the treatment of newly diagnosed APML. Arsenic trioxide was administered at a dose of 10 mg/day until complete remission (CR) was achieved. Afterward, a consolidation course and a maintenance schedule consisting of As(2)O(3) as a single agent were administered over 6 months. There were 3 early deaths related to intra-cerebral hemorrhage: two on day 3 and one on day 4. Of the 11 evaluable patients, one died on day 21 secondary to uncontrolled sepsis, while the remaining 10 (91%) have attained CR. The average time to CR was 52.3 days (range: 34-70 days). One patient developed an isolated central nervous system (CNS) relapse and subsequently went into a second CR following therapy with triple intrathecal chemotherapy, cranial irradiation, and an additional 4-week course of systemic As(2)O(3). This patient, as well as the remaining nine, has continued to remain in CR at a median follow up of 15 months (range: 2-33 months). Eight out of 10 patients achieved molecular remission at variable periods during their consolidation and maintenance schedules. One patient developed an ATRA syndrome and was administered daunorubicin (40 mg/day) for 2 days. The side effects with this therapy were minimal and did not require cessation of therapy in any patient. There was no significant hepatic toxicity. In our experience, arsenic trioxide is effective in inducing and maintaining remission in patients with APML with minimal side effects. The optimal regimen and total dose required need to be defined.     

Mechanism of participation of medial preotic area in the hippocampal inhibition of ovulation

Bilateral hippocampal (HPC) stimulation with anodal direct current on the afternoon of proestrus blocked sponstaneous ovulation in 87.5% of the Wistar rats subjected to the experiments. The incidence of the ovulation block by this procedure was reduced to 16.7% on bilateral injection of 0.25 μg picrotoxin into the medial preoptic area (mPOA) preceding as well as following the stimulation. Ovulation was also blocked in 53.8% of the animals by bilateral injection of 50.0 μg GABA into mPOA, while only 20.0% animals showed a blockade of ovulation of HPC stimulation can be simulated mPOA. These observations indicate that blockade of ovulation by saline injection into by local injection of GABA into mPOA while the effect of stimulation can be blocked by local injection of picrotoxin. Thus, indicating the possibility of GABA being neurotransmitter involved at the level of mPOA for mediating the inhibitory hippocampal influence on ovulation.     

Repeated intracerebral microinjections: efficacy in studying brain functions

Injection of chemicals into the brain has been considered as an important technique to study various functions of the brain. In these studies, as a rule, only one bilateral injection is given in one animal. This study was undertaken to evaluate the quality of the body temperature data obtained after first and second injections of methoxamine and artificial cerebrospinal fluid into the medial preoptic area. Though there was quantitative decrease in the effects produced after the second injection of the drug, there was no significant change in the effects produced by the second injections of artificial cerebrospinal fluid, which was used as a vehicle. Results of this study support the earlier recommendation to perform only one injection in any of the brain sites for evaluating the effect of any drug. But the vehicle can be administered as a second injection, without compromising on the quality of data.     

Sleep-related penile erections do not occur in rats during carbachol-induced rapid eye movement sleep

This study was undertaken to find out whether sleep-related penile erections occur in the carbachol-induced rapid eye movement sleep model in rats. Bulbospongiosus EMG, as a measure of penile erection, was recorded along with EEG, EMG, and EOG during normal sleep-wakefulness. These parameters were again recorded after injection of carbachol into the pontine tegmentum. Carbachol-induced rapid eye movement sleep was not accompanied by penile erections.     

Successful use of ECT as the sole modality of treatment in a case of motility psychosis

Episodic psychoses characterized by predominant abnormalities of movement are called motility psychoses in Leonhard's classification of endogenous psychoses. They have been treated with a variety of methods, including ECT and lithium. Here we describe a case of motility psychosis that was successfully managed with ECT as the only modality of treatment.     

Rare presentation of renal cell carcinoma: Solitary sternal metastasis

Renal cell carcinoma (RCC) may present as metastatic disease. However, RCC with solitary sternal metastasis is rare. We report a rare case of RCC with synchronous solitary sternal metastasis. The patient underwent radical nephrectomy, sternal tumour resection and reconstruction as a one‐stage procedure. The role of open sternal biopsy is also described. Review of the literature was carried out and a reasonably lengthy survival was observed. We concluded that radical surgical resection and reconstruction may offer the best chance of survival in managing RCC with solitary sternal metastasis in renal cell carcinoma.