Suppression of endoplasmic reticulum stress reverses hindlimb unloading-induced hepatic cellular processes in mice

BACKGROUND

The Hindlimb unloaded mouse, an animal model of simulated microgravity demonstrates significant metabolic and hepatic derangements. However, cellular and molecular mechanisms driving liver dysfunction in Hindlimb unloaded mice are poorly characterized.

METHODS

We investigated the possible contribution of dysregulated protein homeostasis by endoplasmic reticulum, endoplasmic reticulum stress, to liver dysfunction during HU. C57BL/6j male mice were grouped into ground-based controls or Hindlimb unloaded groups treated daily with vehicle or 4-phenylbutyrate (4-PBA), a potent inhibitor of endoplasmic reticulum stress. Following three weeks of HU, mice were sacrificed, and liver tissues were dissected for further analysis.

RESULTS

Hindlimb unloaded was associated with hepatic atrophy and elevated endoplasmic reticulum stress, which was restored by 4-PBA treatment. The Gene Ontology analysis revealed the downregulation of genes primarily involved in liver metabolic and Wingless-related integration site (WNT) signaling pathways, while those related to cytochrome P450, and liver fibrosis were upregulated. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed downregulation of several genes involved in metabolic pathways following treatment with 4-PBA, induced by HU.

CONCLUSIONS

We report several differential and uniquely expressed genes associated with microgravity-induced elevated ER stress and liver injury. Our data has translational potential in unraveling novel molecular targets for pharmaceutical therapies of liver diseases.

GENERAL SIGNIFICANCE

Our novel findings show a pathogenic role for elevated ER stress in liver injury in microgravity conditions.

Signature molecular changes in the skeletal muscle of hindlimb unloaded mice

Hind-limb unloaded (HU) mouse is a well-recognized model of muscle atrophy; however, the molecular changes in the skeletal muscle during unloading are poorly characterized. We have used Raman spectroscopy to evaluate the structure and behavior of signature molecules involved in regulating muscle structural and functional health. The Raman spectroscopic analysis of gastrocnemius muscles was compared between 16-18 weeks old HU c57Bl/6J mice and ground-based controls. The spectra showed that the signals for asparagine and glutamine were reduced in HU mice, possibly indicating increased catabolism. The peaks for hydroxyproline and proline were split, pointing towards molecular breakdown and reduced tendon repair. We also report a consistently increased intensity in> 1300 cm-1 range in the Raman spectra along with a shift towards higher frequencies in the HU mice, indicating activation of sarcoplasmic reticulum (SR) stress during HU.

A mixed method study to validate a two-way feedback between student and faculty to improve learning of anatomy

Although the students are subjected to some formative exams throughout the problem based learning units, feedback is not given appropriately and timely. Students want to know and use the reasoning behind judgments and always complain that assessment criteria need to be explained. The aim of this project is to implement a two-way feedback delivery (TWFD), in which both faculty and students have an opportunity to discuss their reflections on learning and examination processes. An Anatomy formative assessment is introduced to 100 students followed by implementation of TWFD. Faculty members provided the students with a structured and timely feedback on their performance. Also, the students reflected on the whole learning process, including real examination experience. The reaction was measured using quantitative and qualitative instruments through a questionnaire, focus group discussion, and semi-structured interviews. Ninety students (90%) participated in the questionnaire with high satisfaction toward implementation of TWFD. Ninety-four percent (n=85) admitted that the time of the session was appropriate. Ninety percent (n=81) of the students demonstrated that the TWFD helped them to identify their strengths and weaknesses. Eighty-five percent (n=77) of the students admitted that TWFD promotes active reflection on the effectiveness of teaching. Most of the students and teachers' comments in the focus group discussions and the interviews supported these results. TWFD seems to be a good approach to implement an effective and timely feedback process between the faculty and the students. Students and the faculty recommended the implementation of this session in different courses and units.

Gastrointestinal and Cardiovascular Safety Profiles of Neratinib Monotherapy in Patients with Advanced ErbB2-Positive Breast Cancer

Background: In a phase 2 study, oral neratinib was administered to patients (pts) with advanced breast cancer in 2 cohorts, those with prior trastuzumab treatment (prior T, n=66) and those with no prior trastuzumab treatment (no prior T, n=70). Neratinib demonstrated robust antitumor activity with objective response rates of 26% and 51%, respectively, and was generally tolerable (Burstein et al. Cancer Res 2009;69:72S). Diarrhea, all grades, occurred in 89% of total pts. Characteristics of the diarrhea and left ventricular ejection fraction (LVEF) measurements are described. Methods: Pts were required to have ErbB2 gene amplification in tumor tissue as measured by fluorescence in situ hybridization by independent assessment. Serial LVEF measurements were made with a multigated acquisition scan or echocardiogram. Pts were ineligible if baseline LVEF was <50%. Adverse events were graded based on the NCI Common Terminology Criteria, v 3.0. Pts received oral neratinib 240 mg daily. Results: Data collected by 18 Mar 2009 are reported; the median (range) duration of neratinib treatment was 4.5 (0.2-23.5) months for pts with prior T and 7.8 (0.5-24.2) months for pts with no prior T. Diarrhea, all grades occurred in 93% of the total population (prior T: 97%, no prior T: 89%); grade 3-4 diarrhea occurred in 21% of the total population (prior T: 30%, no prior T: 13%). Median times of onset were 2 and 3 days after first dose of neratinib, respectively, and median durations of diarrhea were 7 and 5 days. In study week 1, 86% and 73% of pts with prior T and no prior T, respectively, had diarrhea; this decreased to 12-14% in months 3 and 4 (Table). Diarrhea was the cause of dose interruptions in 36% of pts with prior T and 11% of pts with no prior T and of dose reductions in 30% of pts with prior T and 5% of pts with no prior T; only 1 pt (prior T) discontinued treatment due to diarrhea. Pts used anti-diarrheal medications for supportive therapy (prior T: 91%, no prior T: 67%). For LVEF measurements, there was little variation from baseline in most pts during the study. Four pts had at least 1 LVEF measurement <50% (2 of these pts had measurements within the institutional range of normal). None had congestive heart failure. One of these pts had grade 3 atrioventricular block and grade 3 bradycardia, which were considered unrelated to neratinib. Discussion: Neratinib treatment was not associated with clinically significant cardiotoxicity. Pts who developed diarrhea with neratinib monotherapy had early onset, but frequency and severity decreased with time on study. Despite the high frequency of diarrhea with neratinib treatment, it was readily managed with supportive therapy and dose interruptions and/or reductions.Time Course of Diarrhea in ErbB2-Positive Breast Cancer Patients Treated With NeratinibStudy PeriodPrior T: No. on StudyPrior T: % With Diarrhea, All Grades*Prior T: % With Diarrhea, Gr 3-4*No Prior T: No. on StudyNo Prior T: % With Diarrhea, All Grades*No Prior T: % With Diarrhea, Gr 3-4*Week 166861770737Week 2-466611170436Month 260331066152Month 34713060120Month 44312058140*For pts with multiple toxicity grades in a period, the maximum grade was reported.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5096.

A study of anatomical variability of the omohyoid muscle and its clinical relevance

OBJECTIVE

The omohyoid muscle is a long, thin muscle consisting of superior and inferior bellies and an intermediate tendon, which runs obliquely in the lateral cervical region. The omohyoid is important in neck dissections because it is the surgical landmark for level III and IV lymph node metastases.

METHODS

In the present study, the anterior and posterior triangle of the neck was dissected in 35 male cadavers and observed for variations in the omohyoid bilaterally. Observations were focused on variations in number, attachments, and position of omohyoid.

RESULTS

Among the 35 cadavers studied, double omohyoid was present in one cadaver, inferior belly originated from the clavicle in three cadavers, superior belly merged with the sternohyoid in two cadavers, and the omohyoid received additional slips from the sternum in one cadaver. Standard attachment and position of the omohyoid was observed in the remaining cadavers.

CONCLUSION

Variations of this muscle are important because of its close relation to the large vessels and brachial plexus. Because of the direct adhesion of the intermediate tendon to the anterior wall of the internal jugular vein and its connection with it through a thin lamina of the pretracheal layer of the cervical fascia, the contraction of the omohyoid muscle has a direct effect on the lumen of this vessel.

A cadaveric study of the testicular artery in the South Indian population

INTRODUCTION

The male gonadal arteries, namely the testicular arteries, may vary at their origin and arise from the renal artery, suprarenal artery or lumbar artery. They may also be doubled, tripled or even quadrupled and may arise as a common trunk. With the advent of new intra-abdominal operative and laparoscopic techniques, the anatomy of the gonadal vessels has assumed much more importance. Therefore, a study was designed to assess the percentage of normal and aberrant origin and course of the testicular artery in the Indian population.

METHODS

The posterior abdominal walls of 34 male cadavers (68 sides) were dissected and studied for the variations in the origin and course of the testicular arteries.

RESULTS

In 85.3 percent of the cases, the male gonadal artery was normal in origin, number and course. However, in the remaining 14.7 percent, various anomalies in the testicular artery were noted.

CONCLUSION

The variations in the testicular arteries are attributed to their embryological origin. A deep knowledge of these variations and their relations to the adjacent structures is very important in avoiding the complications in operative surgery.

Poisoning in children--analysis of 250 cases

This study is an analysis of 250 cases over a period of 2 years, admitted to our hospital for various poisonings. The total incidence of poisoning was 11.9%, much higher as compared to the other series. Of these, 58.4% were seen in the age group of 1-4 years. Male to female ratio was 1.7:1. Incidence of food poisoning was 48.8% followed by that of kerosene (24%), pesticides (9.6%), chemicals and medicaments (8.4%), plant (3.6%) and animal bites (3.2%). Overall mortality was 0.8%.

Frequency analysis of EEG in rats during the preconvulsive period of O2 poisoning

The EEG of rats exposed to hyperbaric oxygenation (HBO) displays electrical discharges prior to the onset of generalized clinical convulsions (GCC). The characteristics of preconvulsive electrocorticogram (ECoG) in awake, unrestrained rats exposed to 3, 4, and 5 ATA O2 were determined. The ECoG was continuously monitored and analyzed by a hybrid analog-digital system until GCC developed. The time integral of rectified voltage of the individual delta (0.5-4 c/s), theta (4-8 c/s), alpha (8-13 c/s) beta 1 (13-20 c/s), and beta 2 (20-30 c/s) bands were plotted vs. time. An elevation in delta and a temporary reduction in alpha activity before the onset of the first electrical discharge (FED) was observed. There was a continuous reduction in beta 1 and beta 2 frequency bands during the entire pre-electrical discharge period. The activity of theta, and alpha frequency bands was significantly elevated only about 1 min before the onset of the FED, and of beta 1 and beta 2 during appearance of the FED. The possible relationship between the occurrence of preconvulsive EEG changes and pathological effects of hyperbaric oxygenation is discussed.

Computation of decompression schedules for single inert gas-oxygen dives using a hand-held programmable calculator

An algorithm for on-site computation with a hand-held programmable calculator (TI-59, Texas Instruments) of single inert-gas decompression schedules is described. This program is based on Workman's 'M-value' method. It can compute decompression schedules with changes in the oxygen content of the breathing mixture and extension of stay at any decompression stop. The features of the program that enable calculation of atypical dive profiles, along with the portability of small calculators, would make such an algorithm suitable for on-site applications. However, since dive profiles generated by the program have not yet been tested, divers are warned not to generate schedules until their safety has been established by field tests.

Heavy metal-nucleotide interactions. IX. Raman difference spectroscopic studies on the binding of CH3Hg(II) to 1-methylthymine, thymidine-5'-monophosphate, DNA models and native DNA

Raman spectra have been obtained for dTMP and its complex with CH3Hg (II) in aqueous solution as a function of pH. Difference spectroscopy is employed to increase the sensitivity of the Raman technique. The binding reaction is essentially quantitative from pH 3 to 9, and the value of the equilibrium constant for CH3HgOH2+ + dThd in equilibrium CH3Hg(dThdH--1) + H30+ is estimated from intensity measurements to be 0.6 in reasonable agreement with an earlier value based upon uv spectrophotometric data. Binding is to N(3) with substitution of CH3Hg+ for the proton. A similar reaction occurs with 1-MeThy. Raman spectra for aqueous and crystalline 1-MeThy and for the complex CH3Hg(1-MeThyH--1) are reported. The spectrum of crystalline Hg(1-MeThyH--1)2, for which the crystal structure is known, also was obtained for comparison. Raman difference spectroscopy was used to confirm that CH3Hg (II) binds to N(3) of dTMP and N(1) of GMP at r = 0.2 (MeHg+: phosphate) ratios with mixtures of GMP + CMP + AMP + dTMP. In contrast, native calf thymus DNA does not appear to bind CH3Hg(II) at these sites at r = 0.15, although no significant amount of free CH3HgOH is present. With r = 0.3, extensive binding occurs both to the Thy and Gua bases. Raman difference spectroscopy is a valuable technique for studying the binding of ions and molecules to polynucleotides in moderately dilute aqueous solution.