Ceramide accumulation in L6 skeletal muscle cells due to increased activity of ceramide synthase isoforms has opposing effects on insulin action to those caused by palmitate treatment.

AIMS/HYPOTHESIS: An accumulation of ceramides has been implicated in the generation of insulin resistance in skeletal muscle upon an oversupply of fatty acid. Different ceramide species are generated through the actions of ceramide synthases (CerSs), which incorporate specific acyl side chains. We tested whether particular CerS isoforms promoted insulin resistance through the generation of more inhibitory ceramide species, thus representing potential targets for intervention. METHODS: CerS isoforms CerS1, CerS2, CerS4, CerS5 and CerS6 were overexpressed in L6 myotubes using adenovirus, and cells were treated with palmitate and stimulated with insulin. Alternatively, CerS isoforms were knocked down using siRNAs. Sphingolipids were examined by mass spectrometry and tracer incorporation. Phosphorylation of IRS1 and Akt was measured by immunoblotting, while glucose disposal was assessed by measuring GLUT4 translocation and the incorporation of [(14)C]glucose into glycogen. RESULTS: Palmitate treatment increased the levels of several ceramides but reduced the levels of sphingomyelins, while insulin had no effect. The fatty acid also inhibited insulin-stimulated Akt phosphorylation and glycogen synthesis. Overexpression of CerS isoforms increased specific ceramides. Unexpectedly, the overexpression of CerS1 and CerS6 promoted insulin action, while no isoform had inhibitory effects. CerS6 knockdown had effects reciprocal to those of CerS6 overexpression. CONCLUSIONS/INTERPRETATION: Palmitate may increase intracellular ceramide levels through sphingomyelin hydrolysis as well as de novo synthesis, but no particular species were implicated in the generation of insulin resistance. The modulation of ceramides through an alteration of CerS expression does not affect the action of insulin in the same way as ceramide generation by palmitate treatment. Conversely, certain isoforms promote insulin action, indicating the importance of ceramides in cell function.

Ultrasound-Guided Pudendal Nerve Block Combined with Propofol Deep Sedation versus Spinal Anesthesia for Hemorrhoidectomy: A Prospective Randomized Study.

Background and Objectives. Several anesthesia techniques were applied to hemorrhoidectomy, but postoperative pain and urinary retention were still two unsolved problems. The aim of this prospective randomized study was to evaluate the effect of ultrasound-guided pudendal nerve block (PNB) combined with deep sedation compared to spinal anesthesia for hemorrhoidectomy. Methods. One hundred and twenty patients undergoing Milligan-Morgan hemorrhoidectomy were randomized to receive PNB combined with deep sedation using propofol (Group PNB, n = 60) or spinal anesthesia (Group SA, n = 60). Pain intensity was assessed using the visual analogue scale (0: no pain to 10: worst possible pain). The primary outcome was pain scores recorded at rest at 3, 6, 12, 24, 36, and 48 h and on walking at 12, 24, 36, and 48 h postoperatively. Secondary outcomes were analgesic consumption, side effects, and patient satisfaction after surgery. Results. Ultrasound-guided bilateral PNB combined with deep sedation using propofol could successfully be applied to Milligan-Morgan hemorrhoidectomy. Postoperative pain intensity was significantly lower in Group PNB compared to Group SA at rest at 3, 6, 12, 24, 36, and 48 h (p < 0.001) and during mobilization at 12, 24, 36, and 48 h (p < 0.001) postoperatively. Sufentanil consumption in Group PNB was significantly lower than that in Group SA, during 0-24 h (p < 0.001) and during 24-48 h (p < 0.001) postoperatively. Urinary retention was significantly lower in Group PNB compared to Group SA (6.9% vs 20%, p=0.034). The patients in Group PNB had higher satisfaction compared to Group SA (p < 0.001). Conclusions. Ultrasound-guided PNB combined with propofol sedation is an effective anesthesia technique for Milligan-Morgan hemorrhoidectomy.

Design and Biological Evaluation of Novel Imidazolyl Flavonoids as Potent and Selective Protein Tyrosine Phosphatase Inhibitors.

BACKGROUND: Protein tyrosine phosphatases 1B are considered to be a desirable validated target for therapeutic development of type II diabetes and obesity. METHODS: A new series of imidazolyl flavonoids as potential protein tyrosine phosphatase inhibitors were synthesized and evaluated. RESULTS: Bioactive results indicated that some synthesized compounds exhibited potent protein phosphatase 1B (PTP1B) inhibitory activities at the micromolar range. Especially, compound 8b showed the best inhibitory activity (IC50=1.0 µM) with 15-fold selectivity for PTP1B over the closely related T-cell protein tyrosine phosphatase (TCPTP). Cell viability assays indicated that 8b is cell permeable with lower cytotoxicity. Molecular modeling and dynamics studies revealed the reason for selectivity of PTP1B over TCPTP. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity. CONCLUSION: Compound 8b should be a potential selective PTP1B inhibitor.

Gait disorder as a predictor of spatial learning and memory impairment in aged mice.

OBJECTIVE: To investigate whether gait dysfunction is a predictor of severe spatial learning and memory impairment in aged mice. METHODS: A total of 100 12-month-old male mice that had no obvious abnormal motor ability and whose Morris water maze performances were not significantly different from those of two-month-old male mice were selected for the study. The selected aged mice were then divided into abnormal or normal gait groups according to the results from the quantitative gait assessment. Gaits of aged mice were defined as abnormal when the values of quantitative gait parameters were two standard deviations (SD) lower or higher than those of 2-month-old male mice. Gait parameters included stride length, variability of stride length, base of support, cadence, and average speed. After nine months, mice exhibiting severe spatial learning and memory impairment were separated from mice with mild or no cognitive dysfunction. The rate of severe spatial learning and memory impairment in the abnormal and normal gait groups was tested by a chi-square test and the correlation between gait dysfunction and decline in cognitive function was tested using a diagnostic test. RESULTS: The 12-month-old aged mice were divided into a normal gait group (n = 75) and an abnormal gait group (n = 25). Nine months later, three mice in the normal gait group and two mice in the abnormal gait group had died. The remaining mice were subjected to the Morris water maze again, and 17 out of 23 mice in the abnormal gait group had developed severe spatial learning and memory impairment, including six with stride length deficits, 15 with coefficient of variation (CV) in stride length, two with base of support (BOS) deficits, five with cadence dysfunction, and six with average speed deficits. In contrast, only 15 out of 72 mice in the normal gait group developed severe spatial learning and memory impairment. The rate of severe spatial learning and memory impairment was significantly higher in the abnormal gait group as compared to that in the normal gait group (x = 21.986, P < 0.001). All five parameters used to assess gait predicted severe spatial learning and memory impairment in aged mice (P < 0.01). However, the difference of the area under the ROC (receiver operating characteristic) curve for each quantitative gait parameter was not statistically significant. CONCLUSION: Gait disorders are a predictor of severe spatial learning and memory impairment in aged mice, and stride length, variability of stride length, base of support, cadence, and average speed are all sensitive parameters for assessing gait.

SSRI and Motor Recovery in Stroke: Reestablishment of Inhibitory Neural Network Tonus.

Selective serotonin reuptake inhibitors (SSRIs) are currently widely used in the field of the neuromodulation not only because of their anti-depressive effects but also due to their ability to promote plasticity and enhance motor recovery in patients with stroke. Recent studies showed that fluoxetine promotes motor recovery after stroke through its effects on the serotonergic system enhancing motor outputs and facilitating long term potentiation, key factors in motor neural plasticity. However, little is known in regards of the exact mechanisms underlying these effects and several aspects of it remain poorly understood. In this manuscript, we discuss evidence supporting the hypothesis that SSRIs, and in particular fluoxetine, modulate inhibitory pathways, and that this modulation enhances reorganization and reestablishment of excitatory-inhibitory control; these effects play a key role in learning induced plasticity in neural circuits involved in the promotion of motor recovery after stroke. This discussion aims to provide important insights and rationale for the development of novel strategies for stroke motor rehabilitation.

Identification of 10 novel snoRNA gene clusters from Arabidopsis thaliana.

Ten novel small nucleolar RNA (snoRNA) gene clusters, consisting of two or three snoRNA genes, respectively, were identified from Arabidopsis thaliana. Twelve of the 25 snoRNA genes in these clusters are homologous to those of yeast and mammals according to the conserved antisense sequences that guide 2'-O-ribose methylation of rRNA. The remaining 13 snoRNA genes, including two 5.8S rRNA methylation guides, are new genes identified from A.thaliana. Interestingly, seven methylated nucleotides, predicted by novel snoRNAs Z41a-Z46, are methylated neither in yeast nor in vertebrates. Using primer extension at low dNTP concentration the six methylation sites were determined as expected. These snoRNAs were recognized as specific guides for 2'-O:-ribose methylation of plant rRNAs. Z42, however, did not guide the expected methylation of 25S rRNA in our assay. Thus, its function remains to be elucidated. The intergenic spacers of the gene clusters are rich in uridine (up to 40%) and most of them range in size from 35 to 100 nt. Lack of a conserved promoter element in each spacer and the determination of polycistronic transcription from a cluster by RT-PCR assay suggest that the snoRNAs encoded in the clusters are transcribed as a polycistron under an upstream promoter, and individual snoRNAs are released after processing of the precursor. Numerous snoRNA gene clusters identified from A.thaliana and other organisms suggest that the snoRNA gene cluster is an ancient gene organization existing abundantly in plants.

[Changes of microcirculation in healthy volunteers and patients with septic shock in Xining].

OBJECTIVE: The purpose of this study is to investigate the characteristic of microcirculation in healthy volunteers and patients with septic shock in both Xining (2 260 m) and Nanjing (10 m). METHODS: A total of 62 cases, 33 healthy volunteers, 22 cases in Xining, (2 260 m above sea level) and 11 cases in Nanjing (10 m above sea level); and 29 septic shock, 13 cases in Xining and 16 cases in Nanjing were collected. The total vessel density (TVD), perfused vessel density (PVD), proportion of perfused vessel (PPV) and microcirculation flow index (MFI) of both healthy volunteers and septic shock had been investigated by using sidestream dark field (SDF). Analyzed and managed the image data by using AVA3.0 software. RESULTS: In the healthy volunteers in Xining area (22 cases),the volume of TVD (15.59 ±2.58 mm/mm2), PVD (15.58 ±2.58 mm/mm2) and PPV(96.60% ±4.63%) were significant higher than the volume of TVD (10.0 ±2.10 mm/mm2), PVD (10.81 ±2.38 mm/mm2) and PPV (84.24% ±8.00%) of the volunteers (11 cases) in Nanjing (11 cases). But the MFI (2.17 ±0.31) of the healthy volunteers in the Xining was significant lower (P<0.05) than the MFI (3.21 ±0.34) in the healthy volunteers of Nanjing. In the septic shock group (13 cases) in the Xining, the volume of TVD (5.44 ±1.94 mm/mm2), PVD (4.18 ±1.61 mm/mm2), PPV (42.14%±5.38%) and MFI (1.05 ±0.32) compared with the volume of the healthy volunteers in Xining, the TVD (15.59 ±2.58 mm/mm2), PVD (5.58 ±2.58 mm/mm2), PPV (96.60% ±4.63%) and MFI (2.17 ±0.30) were significant lower (P<0.05). In the healthy volunteers compare with septic shock group in Nanjing area, the TVD(6.80±1.72 vs 10.00±2.10, P<0.05), PVD(5.86±1.58 vs10.81±2.38,P<0.05), PPV(45.42±4.86 vs 84.24±4.86, P<0.05), MFI(1.28±0.28 vs 3.21±0.34 P<0.05), there was significant decreased. In the septic shock group in the Xining compared with the septic shock in Nanjing, there was no significant difference. 10 of 13 patients with septic shock were survived in Xining. 13 of 16 patients with septic shock were survived in Nanjing. CONCLUSIONS: The changes of physiological and pathophysiological characteristic in microcirculation induced by hypoxia would be useful for clinical treatment of septic shock at high altitude.

Moderate hypothermia during cardiopulmonary bypass reduces myocardial cell damage and myocardial cell death related to cardiac surgery.

OBJECTIVES: The goal of this study was to test the hypothesis that moderate hypothermia during cardiopulmonary bypass (CPB) provides myocardial protection by enhancing intra-myocardial anti-inflammatory cytokine balance. BACKGROUND: Moderate hypothermia during experimental CPB stimulates production of interleukin-10 (IL10) and blunts release of tumor necrosis factor-alpha (TNFalpha). METHODS: Twelve young pigs were assigned to a temperature (T degrees ) regimen during CPB: moderate hypothermia (T degrees : 28 degrees C; n = 6) and normothermia (T degrees : 37 degrees C; n = 6). Intra-myocardial TNFalpha- and IL10-messenger RNA were detected by competitive reverse transcriptase polymerase chain reaction and quantification of cytokine synthesis by Western blot. Levels of cardiac troponin I (cTnI) in cardiac lymph and in arterial and coronary venous blood were examined during and after CPB. Myocardial cell damage was assessed by histologic and ultrastructural anomalies of tissue probes taken 6 h after CPB. RESULTS: Synthesis of IL10 was significantly higher, while that of TNFalpha was significantly lower, in pigs that were in moderate hypothermia during surgery than in the others. In contrast with normothermia, moderate hypothermia was also associated with significantly lower cumulative cardiac lymphatic flow during and after CPB, significantly lower lymphatic cTnI concentrations after CPB, significantly lower percentages of myocardial cell necrosis and a significantly lower score of ultrastructural anomalies of myocardial cells. While the percentage of apoptotic cells was not different between groups, the apoptosis/necrosis ratio tended to be higher in animals that were in moderate hypothermia during surgery. In all animals, TNFalpha synthesis correlated positively while IL10 production correlated negatively with necrosis and total cell death, respectively. CONCLUSIONS: Our results suggest that moderate hypothermia during CPB provides myocardial protection by enhancing intra-myocardial anti-inflammatory cytokine balance.

The influence of age and gender on the stereoselective metabolism and pharmacokinetics of mephobarbital in humans.

In this clinical investigation, four groups of subjects (eight young women and eight young men [age range, 18 to 25 years], and eight elderly women and eight elderly men [greater than 60 years of age]) received single oral doses (400 mg) of racemic mephobarbital. The apparent total body clearance of R-mephobarbital was much greater and the elimination half-life was much shorter in the young men compared with the other three groups. This enantiomer displayed an age-dependent gender effect and a gender-dependent age effect in its metabolism. The apparent total body clearance of the S-enantiomer was much lower than that of the R-enantiomer in all subjects and did not differ between subject groups, although the elimination half-life was slightly but significantly shorter in young males. A consequence of these enantiomeric differences was an apparently enhanced stereoselectivity in the metabolism of mephobarbital in young men. These substantial influences of age and gender on the stereoselective disposition of mephobarbital are consistent with recent findings concerning the expression and regulation of cytochrome P450 enzymes.

Influence of temperature during cardiopulmonary bypass on leukocyte activation, cytokine balance, and post-operative organ damage.

This study examined the hypothesis that core temperature (T(o)) during cardiopulmonary bypass (CPB) influences the perioperative systemic inflammatory response and post-operative organ damage. Twenty-four pigs were assigned to a T(o) regimen during CPB: normothermia (T(o) 37 degrees C; n = 8), moderate hypothermia (T(o) 28 degrees C; n = 8), or deep hypothermia (T(o) 20 degrees C; n = 8). Perioperative leukocyte activation, endotoxin release, and production of tumor necrosis factor-alpha (TNFalpha) and interleukin-10 (IL10) were examined with regard to post-operative organ damage, which was scored at histological examination of tissue probes of heart, lungs, liver, kidney, and ileum, taken 6 h after CPB. Total blood leukocyte count and TNFalpha plasma levels during CPB were significantly lower and IL10 levels were significantly higher in the moderate hypothermic group than in both other groups. Elastase activity, leukotriene B4-, and endotoxin levels were not affected by T(o) regimen. Moderate hypothermia was associated with the lowest histological organ damage score and normothermia with the highest. In all animals organ damage score for heart, lungs, and kidneys correlated significantly with TNFalpha levels at the end of CPB. Our data demonstrate a clear relationship between TNFalpha production during cardiac operations and post-operative multiple-organ damage. Moderate hypothermia, by stimulating IL10 synthesis and suppressing TNFalpha production during CPB, might provide organ protection.

Cannulation of the cardiac lymphatic system in swine.

OBJECTIVE: Cardiac lymph is the most direct medium for analyzing metabological changes in the myocardial cell. Currently, dogs are the animals used for investigation of myocardial lymphatic function. However, questions arise when comparing and interpreting the human system to the experimental model, since the dog coronary anatomy is different from human anatomy and pulmonary lymph contamination is found in up to 81% of the cases. Swine, having similar coronary anatomy to humans, are a proven model for cardiovascular research. The purpose of this study was to investigate the cardiac lymphatic anatomy of the swine and to develop a reliable cannulation technique to collect the lymph. METHODS AND RESULTS: The lymphatic anatomy of 60 pigs was studied and classified and a new technique for lymphatic cannulation was developed. The cannulation success rate was 55%. In addition, no pulmonary lymph contamination was found at the cannulation site. CONCLUSION: We conclude that porcine myocardial lymphatics can be successfully cannulated for the investigation of myocardial lymphatic function.

[Bone mineral density and exercises: a cross-sectional study on Chinese athletes].

OBJECTIVES: To evaluate the effect of exercise to osteoporosis by bone mineral density (BMD) measurement of athelets comparing normal individuals in general population. METHODS: BMD of radium, lumber spine, and femoral neck were measured by single photon absorptiometry (SPA), quantitative CT (QCT), and dual X-ray absorptiometry (DXA) respectively in athletes (n = 162, male 79, female 83) and age matched non-athletes normal population (n = 204, male 91, female 113) in Beijing. RESULTS: BMD of all sites in all age groups of both male and female athletes are significantly higher comparing with that in non-athletic population. This predominance in athletes is even more distinctive in peak bone mass. Peak bone mass of male athletes is significantly higher than that of female athletes. Bone loss with age is less apparent in athletes than in control. However, there is an accelerated decline of BMD in lumber spine and femoral neck in 30-39 year age group in both male and female athletes, which may be due to the wanting of physical exercise. CONCLUSIONS: Long term regular proper exercise started in adolescence may play a very important role in the prevention of osteoporosis by improving peak bone mass and decreasing bone loss.

Ichthyosis uteri: a case report and review of the literature.

Squamous metaplasia of endometrium is mostly manifested by morules or nodules of benign nonkeratinizing squamous cells intimately mixed with benign or malignant endometrial glands. It has been described with low-grade adenocarcinoma of the endometrium, as well as with various benign conditions, including hyperplasia, chronic endometritis, and endometrial polyps. However, extensive plaquelike, keratinizing squamous change is distinctly uncommon. To our knowledge, we describe the first case of extensive benign squamous keratinization with underlying endometrial adenocarcinoma.

Systemic inflammatory response to cardiac surgery: does female sex really protect?

Sex hormones have important interactions with the immune system and modulate the inflammatory response. In this regard, oestrogen inhibits the transcription of proinflammatory cytokines and confers tissue protection in experimental models. On the basis of this evidence, Trotter et al. in this issue of Critical Care addressed the question of whether, in children, female sex would protect against the deleterious effects of cardiac operations with cardiopulmonary bypass by providing a favourable anti-inflammatory cytokine balance. The observations made in that study suggest sex-related immunomodulation and organ protection during cardiac surgery in the paediatric population. Prospective trials conducted in large series, including sex hormone determination in neonates, infants and children with congenital cardiac defects, are necessary to test this hypothesis. The verification of sex-related intraoperative organ protection would provide new opportunities for preventing the uncontrolled systemic inflammatory response that may occur during cardiac surgery.

Enantioselective pharmacokinetics of ethotoin in humans following single oral doses of the racemate.

Racemic ethotoin (1000 mg) was administered orally as a single dose to six healthy adult volunteers. Blood samples were collected at appropriate times for 120 h following the dose. Ethotoin was quantified enantio-selectively in plasma using a novel chiral column HPLC procedure. One of the enantiomers of the chiral metabolite, 5-phenylhydantoin, was also quantified in the HPLC method. The Cmax and AUC0-infinity values for (+)-(S)-ethotoin were significantly greater than those for (-)-(R)-ethotoin (ratio of mean AUC0-infinity values 0.88), but the elimination half-lives of the isomers were virtually identical [12.35 +/- 5.15 h for (-)-(R)-ethotoin; 12.28 +/- 5.34 h for (+)-(S)-ethotoin]. Parameters derived from AUC0-infinity (Cl0/F and V(area)/F) also differed slightly between the isomers. The data were interpreted as indicating a small difference in the absorption of the two isomers; it seemed unlikely, in terms of the identical elimination rates, that their metabolic profiles would differ greatly. The 5-phenylhydantoin was eliminated with a significantly longer half-life (18.69 +/- 6.11 h) than that of ethotoin. Enantioselectivity in the pharmacokinetics of ethotoin is therefore a minor issue.