Effects of thermal environment on sleep and circadian rhythm

The thermal environment is one of the most important factors that can affect human sleep. The stereotypical effects of heat or cold exposure are increased wakefulness and decreased rapid eye movement sleep and slow wave sleep. These effects of the thermal environment on sleep stages are strongly linked to thermoregulation, which affects the mechanism regulating sleep. The effects on sleep stages also differ depending on the use of bedding and/or clothing. In semi-nude subjects, sleep stages are more affected by cold exposure than heat exposure. In real-life situations where bedding and clothing are used, heat exposure increases wakefulness and decreases slow wave sleep and rapid eye movement sleep. Humid heat exposure further increases thermal load during sleep and affects sleep stages and thermoregulation. On the other hand, cold exposure does not affect sleep stages, though the use of beddings and clothing during sleep is critical in supporting thermoregulation and sleep in cold exposure. However, cold exposure affects cardiac autonomic response during sleep without affecting sleep stages and subjective sensations. These results indicate that the impact of cold exposure may be greater than that of heat exposure in real-life situations; thus, further studies are warranted that consider the effect of cold exposure on sleep and other physiological parameters

Disseminated Cryptococcal Disease in a Patient with Chronic Lymphocytic Leukemia on Ibrutinib

Cryptococcus is a unique environmental fungus that can cause disease most often in immunocompromised individuals with defective cell-mediated immunity. Chronic lymphocytic leukemia (CLL) is not known to be a risk factor for cryptococcal disease although cases have been described mainly in patients treated with agents that suppress cell-mediated immunity. Ibrutinib is a new biologic agent used for treatment of CLL, mantle cell lymphoma, and Waldenstrom’s macroglobulinemia. It acts by inhibiting Bruton’s tyrosine kinase, a kinase downstream of the B-cell receptor critical for B-cell survival and proliferation. Ibrutinib use has not been associated previously with cryptococcal disease. However, recent evidence suggested that treatments aimed at blocking the function of Bruton’s tyrosine kinase could pose a higher risk for cryptococcal infection in a mice model. Here, we report the first case of disseminated cryptococcal disease in a patient with CLL treated with ibrutinib. When evaluating possible infection in CLL patients receiving ibrutinib, cryptococcal disease, which could be life threatening if overlooked, could be considered

Dominant negative mutant Cyclin T1 proteins inhibit HIV transcription by specifically degrading Tat

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Generation of Micronuclei during Interphase by Coupling between Cytoplasmic Membrane Blebbing and Nuclear Budding

Micronucleation, mediated by interphase nuclear budding, has been repeatedly suggested, but the process is still enigmatic. In the present study, we confirmed the previous observation that there are lamin B1-negative micronuclei in addition to the positive ones. A large cytoplasmic bleb was found to frequently entrap lamin B1-negative micronuclei, which were connected to the nucleus by a thin chromatin stalk. At the bottom of the stalk, the nuclear lamin B1 structure appeared broken. Chromatin extrusion through lamina breaks has been referred to as herniation or a blister of the nucleus, and has been observed after the expression of viral proteins. A cell line in which extrachromosomal double minutes and lamin B1 protein were simultaneously visualized in different colors in live cells was established. By using these cells, time-lapse microscopy revealed that cytoplasmic membrane blebbing occurred simultaneously with the extrusion of nuclear content, which generated lamin B1-negative micronuclei during interphase. Furthermore, activation of cytoplasmic membrane blebbing by the addition of fresh serum or camptothecin induced nuclear budding within 1 to 10 minutes, which suggested that blebbing might be the cause of the budding. After the induction of blebbing, the frequency of lamin-negative micronuclei increased. The budding was most frequent during S phase and more efficiently entrapped small extrachromosomal chromatin than the large chromosome arm. Based on these results, we suggest a novel mechanism in which cytoplasmic membrane dynamics pulls the chromatin out of the nucleus through the lamina break. Evidence for such a mechanism was obtained in certain cancer cell lines including human COLO 320 and HeLa. The mechanism could significantly perturb the genome and influence cancer cell phenotypes

Emergence of Micronuclei and Their Effects on the Fate of Cells under Replication Stress

The presence of micronuclei in mammalian cells is related to several mutagenetic stresses. In order to understand how micronuclei emerge, behave in cells, and affect cell fate, we performed extensive time-lapse microscopy of HeLa H2B-GFP cells in the presence of hydroxyurea at low concentration. Micronuclei formed after mitosis from lagging chromatids or chromatin bridges between anaphase chromosomes and were stably maintained in the cells for up to one cell cycle. Nuclear buds also formed from chromatin bridges or during interphase. If the micronuclei-bearing cells entered mitosis, they either produced daughter cells without micronuclei or, more frequently, produced cells with additional micronuclei. Low concentrations of hydroxyurea efficiently induced multipolar mitosis, which generated lagging chromatids or chromatin bridges, and also generated multinuclear cells that were tightly linked to apoptosis. We found that the presence of micronuclei is related to apoptosis but not to multipolar mitosis. Furthermore, the structural heterogeneity among micronuclei, with respect to chromatin condensation or the presence of lamin B, derived from the mechanism of micronuclei formation. Our study reinforces the notion that micronucleation has important implications in the genomic plasticity of tumor cells

Cyclin T1 stabilizes expression levels of HIV-1 Tat in cells

Transcription from HIV-1 proviral DNA is a rate-determining step for HIV-1 replication. Interaction between the cyclin T1 (CycT1) subunit of positive transcription elongation factor b (P-TEFb) and the Tat transactivator protein of HIV-1 is crucial for viral transcription. CycT1 also interacts directly with the transactivation-responsive element (TAR) located on the 5′end of viral mRNA, as well as with Tat through the Tat–TAR recognition motif (TRM). These molecular interactions represent a critical step for stimulation of HIV transcription. Thus, Tat and CycT1 are considered to be feasible targets for the development of novel anti-HIV therapies. In this study, we demonstrate that CycT1 is positively involved in the Tat protein stability. Selective degradation of CycT1 by small interfering RNA (siRNA) culminated in proteasome-mediated degradation of Tat and eventual inhibition of HIV-1 gene expression. We noted that the siRNA-mediated knockdown of CycT1 could inhibit HIV-1 transcription without affecting cell viability and Tat mRNA levels. These findings clearly indicate that CycT1 is a feasible therapeutic target, and inactivation or depletion of CycT1 should effectively inhibit HIV replication by destabilizing Tat and suppressing Tat-mediated HIV transcription.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78606/1/j.1742-4658.2009.07424.x.pd

Endocrine Profile in Rats with Postgastrectomy Malabsorption: a Pilot Study

Abnormal endocrine profile, especially in the enteropancreatic axis, was described in rats with malnutrition caused by malabsorption after total gastrectomy. Insulin, substance P and motilin concentrations at the fasting condition were significantly elevated in malnutritious rats after total gastrectomy when compared to those in control rats. A significant elevation of pancreatic glucagon and motilin was noted after intraduodenal fat administration in malnutritious rats. These data suggest that these peptides of many humoral factors may thus cause abnormal enteropancreatic axis and consequent malnutrition

The antioxidant N-acetyl cysteine suppresses lidocaine-induced intracellular reactive oxygen species production and cell death in neuronal SH-SY5Y cells

Analysis of cell apoptosis by FACS. Levels of cell apoptosis were measured using an Annexin V-FITC Apoptosis Detection Kit (BioVision, Milpitas, CA, USA), according to the manufacturer’s instructions. For these analyses, SH-SY5Y cells were seeded into 6-well plates (3 × 105 cells/well) and incubated overnight. The following day, cells were treated with the indicated concentrations of the appropriate drug(s) for varying lengths of time and harvested by centrifugation at 1200 rpm for 3 min. The culture supernatants were discharged, and the resulting pellets were resuspended in a mixture comprised of 500 μl binding buffer, 5 μl Annexing V-FITC, and 5 μl propidium iodide (PI; 50 μg/ml) for 5 min at room temperature in the dark and analyzed using a FACSCalibur flow cytometer (BD Biosciences, San Jose, CA, USA). (PDF 2009 kb

Gastrin and Somatostatin in Patients with Hyperchlorhydric Duodenal Ulcer

Hormonal and morphological studies were conducted to ascertain the role played by gastrin and somatostatin in the pathophysiology of duodenal ulcer, in particular hyperchlorhydric duodenal ulcer, using 35 patients with duodenal ulcer, of whom 15 were hyperchlorhydric and 20 were normochlorhydric. Twenty normal subjects with normochlorhydria were used as a control. In patients with hyperchlorhydric duodenal ulcer following significant findings were observed: 1. Basal and stimulated hyperchlorhydria, 2. Parietal cell hyperplasia, 3. Basal hypergastrinemia, 4. Increased concentration of gastrin and large number of G cells (G cell hyperplasia) in the antral mucosa. 5. Mucosal concentration of somatostatin and D cells in the antrum was reduced, but the former in patients with hyperchlorhydric duodenal ulcer was not different from that in patients with normoacidic duodenal ulcer. 6. A significant correlation in mucosal concentration was demonstrated between gastrin and somatostatin in control subjects but not in patients with duodenal ulcer. 7. There was a significant correlation in maximal acidity in gastric secretion and mucosal concentration of antral somatostatin in control subjects but not in patients with duodenal ulcer. 8. Concentration of plasma somatostatin in patients with duodenal ulcer was not different from that in control subjects. These findings indicate that gastrin and somatostatin may participate in the pathophysiology of duodenal ulcer, at least in the subgroup of duodenal ulcer associated with hyperchlorhydria, and the subgroup of duodenal ulcer may be an endocrine disorder

Cryptococcus gattii Genotype VGIIa Infection in Man, Japan, 2007

We report a patient in Japan infected with Cryptococcus gattii genotype VGIIa who had no recent history of travel to disease-endemic areas. This strain was identical to the Vancouver Island outbreak strain R265. Our results suggest that this virulent strain has spread to regions outside North America