Diurnal regulation of metabolism by Gs-alpha in hypothalamic QPLOT neurons.

Neurons in the hypothalamic preoptic area (POA) regulate multiple homeostatic processes, including thermoregulation and sleep, by sensing afferent input and modulating sympathetic nervous system output. The POA has an autonomous circadian clock and may also receive circadian signals indirectly from the suprachiasmatic nucleus. We have previously defined a subset of neurons in the POA termed QPLOT neurons that are identified by the expression of molecular markers (Qrfp, Ptger3, LepR, Opn5, Tacr3) that suggest receptivity to multiple stimuli. Because Ptger3, Opn5, and Tacr3 encode G-protein coupled receptors (GPCRs), we hypothesized that elucidating the G-protein signaling in these neurons is essential to understanding the interplay of inputs in the regulation of metabolism. Here, we describe how the stimulatory Gs-alpha subunit (Gnas) in QPLOT neurons regulates metabolism in mice. We analyzed Opn5cre; Gnasfl/fl mice using indirect calorimetry at ambient temperatures of 22°C (a historical standard), 10°C (a cold challenge), and 28°C (thermoneutrality) to assess the ability of QPLOT neurons to regulate metabolism. We observed a marked decrease in nocturnal locomotion of Opn5cre; Gnasfl/fl mice at both 28°C and 22°C, but no overall differences in energy expenditure, respiratory exchange, or food and water consumption. To analyze daily rhythmic patterns of metabolism, we assessed circadian parameters including amplitude, phase, and MESOR. Loss-of-function GNAS in QPLOT neurons resulted in several subtle rhythmic changes in multiple metabolic parameters. We observed that Opn5cre; Gnasfl/fl mice show a higher rhythm-adjusted mean energy expenditure at 22°C and 10°C, and an exaggerated respiratory exchange shift with temperature. At 28°C, Opn5cre; Gnasfl/fl mice have a significant delay in the phase of energy expenditure and respiratory exchange. Rhythmic analysis also showed limited increases in rhythm-adjusted means of food and water intake at 22°C and 28°C. Together, these data advance our understanding of Gαs-signaling in preoptic QPLOT neurons in regulating daily patterns of metabolism.

Circadian disruption and cisplatin chronotherapy for mammary carcinoma.

Solid tumors are commonly treated with cisplatin, which can cause off-target side effects in cancer patients. Chronotherapy is a potential strategy to reduce drug toxicity. To determine the effectiveness of timed-cisplatin treatment in mammals, we compared two conditions: clock disrupted jet-lag and control conditions. Under normal and disrupted clock conditions, triple-negative mammary carcinoma cells were injected subcutaneously into eight-week-old NOD.Cg-Prkdcscid/J female mice. Tumor volumes and body weights were measured in these mice before and after treatment with cisplatin. We observed an increase in tumor volumes in mice housed under disrupted clock compared to the normal clock conditions. After treatment with cisplatin, we observed a reduced tumor growth rate in mice treated at ZT10 compared to ZT22 and untreated cohorts under normal clock conditions. However, these changes were not seen with the jet-lag protocol. We also observed greater body weight loss in mice treated with ZT10 compared to ZT22 or untreated mice in the jet-lag protocol. Our observations suggest that the effectiveness of cisplatin in mammary carcinoma treatment is time-dependent in the presence of the circadian clock.

Aloe vera modulates X-ray induced hematological and splenic tissue damage in mice.

The present study was premeditated to examine the radioprotective effects of aqueous Aloe vera gel extract against whole-body X-ray irradiation-induced hematological alterations and splenic tissue injury in mice. Healthy male balb/c mice were divided into four groups: group 1, control; group 2, A. vera (50 mg/kg body weight) administered per oral on alternate days for 30 days (15 times); group 3, X-ray exposure of 2 Gy (0.25 Gy twice a day for four consecutive days in the last week of the experimental protocol); and group 4, A. vera + X-ray. X-ray exposure caused alterations in histoarchitecture of spleen along with enhanced clastogenic damage as assessed by micronucleus formation and apoptotic index. Irradiation caused an elevation in proinflammatory cytokines like tumor necrosis factor and interleukin-6, total leucocyte counts, neutrophil counts and decreased platelet counts along with unaltered red blood cell counts and hemoglobin. Irradiation also caused an elevation in reactive oxygen species (ROS), lipid peroxidation (LPO) levels, lactate dehydrogenase activity and alterations in enzymatic and nonenzymatic antioxidant defense mechanism in plasma and spleen. However, administration of A. vera gel extract ameliorated X-ray irradiation-induced elevation in ROS/LPO levels, histopathological and clastogenic damage. It also modulated biochemical indices, inflammatory markers, and hematological parameters. These results collectively indicated that the A. vera gel extract offers protection against whole-body X-ray exposure by virtue of its antioxidant, anti-inflammatory and anti-apoptotic potential.

Protective role of Aloe vera against X-ray induced testicular dysfunction.

The present investigation was carried out to evaluate the possible radioprotective potential of an Aloe vera extract against whole-body X-ray irradiation-induced testicular alterations in mice. Male balb/c mice were divided into four groups: control, A. vera, X-ray and A. vera pre-treated + X-ray irradiated. Histopathological examination revealed significant structural alterations in testes after X-ray exposure, which was also associated with the presence of apoptotic cells as assessed by TUNEL assay. X-ray irradiation resulted in elevation in the levels of reactive oxygen species, lipid peroxidation, a reduction in glutathione concentration and enhanced activities of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, catalase, superoxide dismutase and glutathione-S-transferase. Sperm count/motility and testosterone levels were significantly decreased in the irradiated group. Irradiated animals pre-treated with A. vera extract revealed an improvement in antioxidant status, inhibition of lipid peroxides, apoptotic cell formation and enhanced testicular parameters when compared to the X-ray-exposed group. These findings suggest that A. vera extract could ameliorate X-ray-induced damage due to its free radical scavenging properties and its potential to boost cellular antioxidant defence machinery.

Anaesthesia for laparoscopic cholecystectomy in Bartter's syndrome.

Bartter's syndrome is a rare inherited anamoly with defect in the thick segment of the ascending limb of the loop of Henle, with reduced reabsorption of potassium. Growth is affected with worsening renal function, hypokalaemia, hypochloraemic metabolic alkalosis, hypocalcemia, hypomagnesemia, increased levels of aldosterone, renin and angiotensin without hypertension and lack of responses to vasopressors. Treatment consists of potassium supplementation along with other medications. We present the case report, probably the first, of a child suffering from Bartter's syndrome with gall stones posted for laparoscopic cholecystectomy. The pre-operative correction of hypokalemia and successful anaesthetic and fluid and electrolyte management of the patient are discussed.

Changes in superior mesenteric artery blood flow after oral, enteral, and parenteral feeding in humans.

OBJECTIVE: Alterations in splanchnic blood flow cause gut ischemia and may predispose to gut-derived sepsis. Increases in superior mesenteric artery (SMA) blood flow occur follow the oral ingestion of food, but the effects of enteral nutrition (EN) on splanchnic perfusion are poorly defined and those of parenteral nutrition (PN) are unknown in humans. The aim of this study was to investigate changes in SMA flow in healthy controls and patients receiving adjuvant nutrition. DESIGN: Qualitative before-after study. SETTING: Intensive care and general wards at Scarborough Hospital, Scarborough, United Kingdom. PATIENTS: Fourteen healthy volunteers and 20 consecutive hemodynamically stable patients receiving adjuvant nutrition. INTERVENTIONS: Oral, EN, or PN after an overnight fast. MEASUREMENTS AND MAIN RESULTS: Duplex ultrasonography was used to assess SMA flow after an overnight fast. Subjects were then rescanned 3 hrs later after commencement of the appropriate test feed so that postprandial flows could be determined. Of the 20 patients recruited, 10 were receiving EN (120 kcal) and 10 PN (175 kcal). Of the 14 volunteers, three received no feed before their second scan (controls), six received an oral meal (530 kcal), and five received EN (120 kcal). Changes in SMA flow within groups were assessed. The control (fasting) volunteers showed no change between the two scans (p = 1.000). All subjects fed intraluminally demonstrated significant increases in postprandial SMA blood flow. Conversely, all patients fed parenterally showed decreased postprandial SMA flows with a median (interquartile range) fasting SMA flow of 14.5 (4.8-24.8) mL/sec, which decreased to 6.1 (2.4-9.2) mL/sec postprandially (p = 0.013). CONCLUSIONS: Splanchnic flow is modulated by the route of feeding. The clinical significance of these findings requires further investigation as they may be important in the management of the critically ill patient, particularly in those with cardiovascular instability or any patient predisposed to gut ischemia.

An improved method for the analysis of sennosides in Cassia angustifolia by high-performance liquid chromatography.

A reversed-phase column liquid chromatographic method for the analysis of sennosides A and B present in leaf and pod extracts of Cassia angustifolia has been developed using a Symmetry C18 column and a linear binary gradient profile. The method can be utilised for the quantitative determination of other sennosides as a baseline resolution for most of the constituents was achieved. The method is economical in terms of the time taken and the amount of solvent used (25 mL) for each analysis. The validity of the method with respect to analysis was confirmed by comparing the UV spectra of each peak with those of reference compounds using a photodiode array detector.

Copper repletion restores the number and function of CD4 cells in copper-deficient rats.

Dietary copper deficiency decreases the number of splenic CD4 cells and mitogen-induced generation of interleukin-2 activity and DNA synthesis in cultures of splenic mononuclear cells. To determine the reversibility of these defects, Cu-deficient rats were fed a Cu-adequate diet for either 4, 7 or 11 d before preparation of cell cultures. Serum and hepatic concentrations of Cu attained 87 and 75%, respectively, of the control level after 4 d of dietary repletion. In contrast, interleukin-2 activity and [3H]thymidine incorporation in splenic cell cultures treated with T-cell mitogens were significantly greater than in cultures from Cu-deficient rats after 7, but not 4, d of dietary Cu repletion. The number of splenic CD4 cells was also greater after 7 d of dietary supplementation with Cu. Changes in the relative percentage and function of T-helper cells were highly correlated with one another and with hepatic Cu concentration. These observations indicate that an inadequate supply of dietary Cu reversibly suppresses the maturation and function of splenic T-helper cells.

Studies on antimutagenic effects of guava (Psidium guajava) in Salmonella typhimurium.

The water and chloroform extracts of guava were tested for their antimutagenicity. The water extract was effective in inactivating the mutagenicity of direct-acting mutagens, e.g., 4-nitro-o-phenylenediamine, sodium azide, and the S9-dependent mutagen, 2-aminofluorene, in the tester strains of Salmonella typhimurium. The chloroform extract was inactive. Autoclaving of the water extract for 15 min did not reduced its activity appreciably. The enhanced inhibitory activity of the extracts on pre-incubation suggests the possibility of desmutagens in the extracts. Besides ascorbic acid and citric acid, the major constituents of the extracts, the role of other antimutagenic factors in the extracts cannot be ruled out.

Copper deficiency reversibly impairs DNA synthesis in activated T lymphocytes by limiting interleukin 2 activity.

The essentiality of adequate copper (Cu) nutriture for normal T-cell function in laboratory and domestic animals is well established. However, specific biochemical roles of Cu in the maturation and activation of T cells have not been defined. Previous work showed that when cultures of splenic mononuclear cells (MNCs) from Cu-deficient rats were exposed to T-cell mitogens, DNA synthesis was markedly reduced despite normal up-regulation of interleukin 2 (IL-2) receptors, transferrin receptors, and class II major histocompatibility complex molecules. In the present study, IL-2 activity in PHA-treated cultures of MNCs from Cu-deficient rats was 40-50% that of controls as determined by bioassay. Addition of rat IL-2 to phytohemagglutinin-treated cultures of MNCs from Cu-deficient rats increased blastogenic activity to control levels, demonstrating that Cu deficiency does not inhibit transition of quiescent cells to the competence phase of the activation process. Moreover, supplementation of MNC cultures from Cu-deficient rats with physiological levels of Cu enhanced IL-2 activity and DNA synthesis in response to phytohemagglutinin. These data indicate that IL-2 activity in cultures of activated splenic T lymphocytes from Cu-deficient rats is insufficient for optimal blastogenesis.

Antimutagenic activity of Terminalia chebula (myroblan) in Salmonella typhimurium.

Antimutagenicity of water and chloroform extracts of dried myroblan Terminalia chebula was determined against two direct acting mutagens, sodium azide and 4-nitro-o-phenylenediamine (NPD) in strains TA100 and TA1535, and TA97a and TA98 of Salmonella typhimurium respectively and S9-dependent mutagen 2-aminofluorene (2-AF) in TA97a, TA98 and TA100 strains. Water extract reduced NPD as well as 2-AF induced his+ revertants significantly but did not have any perceptible effect against sodium azide included his+ revertants in TA100 and TA1535 strains of S. typhimurium. The pre-incubation studies, where the extract was incubated at 37 degrees C for 30 min with the said mutagen prior to plating, enhanced the inhibitory effect. Autoclaving the water extract reduced the inhibitory effect but the reduction in the effect was not significant. No inhibitory effect was observed in any of the strains and against any of the test mutagens with chloroform extract.

Prolonged cataleptogenic effects of potentized homoeopathic drugs.

The four homoeopathic drugs, Gelsemium, Cannabis Indica, Graphites and Agaricus Muscarius, administered orally in 30th and 200th potencies on white rats, enhanced restraint-induced catalepsy in a similar manner to the two standard drugs pilocarpine and haloperidol (IP injection at 5 mg/kg). All the drugs tested differed from each other in the duration of cataleptogenic effect, which was more prolonged with Cannabis, Graphites and Agaricus than with Gelsemium and the two non-homoeopathic drugs used. The 200th potency of any homoeopathic drug tested acted longer than its 30th potency.