Melatonin stimulates transcription of the rat phosphoenolpyruvate carboxykinase gene in hepatic cells.

Melatonin plays physiological roles in various critical processes, including circadian rhythms, oxidative stress defenses, anti-inflammation responses, and immunity; however, the current understanding of the role of melatonin in hepatic glucose metabolism is limited. In this study, we examined whether melatonin affects gene expression of the key gluconeogenic enzyme, phosphoenolpyruvate carboxykinase (PEPCK). We found that melatonin treatment increased PEPCK mRNA levels in rat highly differentiated hepatoma (H4IIE) cells and primary cultured hepatocytes. In addition, we found that melatonin induction was synergistically enhanced by dexamethasone, whereas it was dominantly inhibited by insulin. We also report that the effect of melatonin was blocked by inhibitors of mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK), RNA polymerase II, and protein synthesis. Furthermore, the phosphorylated (active) forms of ERK1 and ERK2 (ERK1/2) increased 15 min after melatonin treatment. We performed luciferase reporter assays to show that melatonin specifically stimulated promoter activity of the PEPCK gene. Additional reporter analysis using 5'-deleted constructs revealed that the regulatory regions responsive to melatonin mapped to two nucleotide regions, one between -467 and -398 nucleotides and the other between -128 and +69 nucleotides, of the rat PEPCK gene. Thus, we conclude that melatonin induces PEPCK gene expression via the ERK1/2 pathway at the transcriptional level, and that induction requires de novo protein synthesis.

Correlation between family physician's direct advice and pneumococcal vaccination intention and behavior among the elderly in Japan: a cross-sectional study.

BACKGROUND: Vaccination is an important element of health maintenance in family medicine. The 23-valent pneumococcal polysaccharide vaccine (PPSV23) is highly recommended for the elderly, but its uptake is low in Japan. Primary care system remains under development and preventive services tend to be neglected in the Japanese medical practice. The study aims to investigate the association between family physician's recommendations for PPSV23 during outpatient care and PPSV23 vaccination intention and behavior in the elderly. METHOD: We conducted a cross-sectional study with a questionnaire at a family medicine clinic in a rural area in Japan. The participants were over the age of 65 without dementia who had maintained a continuity with the clinic. The questionnaire inquired PPSV23 vaccination status, family physician's advice for PPSV23, socio-demographics, and the constructs in the Health Belief Model. We defined those who had had vaccination intention and behavior as "PPSV23 vaccinated group" and those who had no vaccination and uncertainty about being or no intention to be vaccinated in the future as "PPSV23 unvaccinated group." We used chi-square test for correlation between physician's advice and PPSV23 vaccination/intention, univariate and multivariate logistic regression analysis for factors related to the vaccination/intention, and descriptive analysis for reasons for reluctance to the vaccination. RESULTS: We analyzed 209 valid responses. There were 142 participants in the PPSV23 vaccinated group and 67 in the PPSV23 unvaccinated group. The PPSV23 vaccination group was more likely to have had their physician's advice (80.2% vs 21.3%, p < 0.001). Multivariate logistic regression analysis showed a significant association between PPSV23 vaccination and their physician's recommendation (OR 8.50, 95%CI 2.8-26.0), awareness of PPSV23 (OR 8.52, 95%CI 2.1-35.0), and the perceived effectiveness of PPSV23 (OR 4.10, 95%CI 1.2-13.9). The reasons for reluctance to get vaccinated included lack of understanding of PPSV23, lack of physician's recommendations, and concerns about side effects of PPSV23. CONCLUSION: Family physician's recommendation was positively correlated with PPSV23 vaccination intention and behavior in the elderly. This reinforces the importance of providing preventive services during time-constrained outpatient care, even in medical systems where it is undervalued.

Development of a simulation method for dynamics of electrons ejected from DNA molecules irradiated with X-rays.

PURPOSE: To develop a method for simulating the dynamics of the photoelectrons and Auger electrons ejected from DNA molecules irradiated with pulsed monochromatic X-rays. MATERIALS AND METHODS: A 30-base-pair (bp) DNA molecule was used as the target model, and the X-rays were assumed to have a Gaussian-shaped time distribution. Photoionization and Auger decay were considered as the atomic processes. The atoms from which the photoelectrons or Auger electrons were emitted were specified in the DNA molecule (or DNA ion) using the Monte Carlo method, and the trajectory of each electron in the electric field formed around the positively charged DNA molecule was calculated with a Newtonian equation. The kinetics of the electrons produced by irradiation with X-rays at an intensity ranging from 1 × 10(12) to 1 × 10(16) photons/mm(2) and energies of 380 eV (below the carbon K-edge), 435 eV (above the nitrogen K-edge), and 560 eV (above the oxygen K-edge) were evaluated. RESULTS: It was found that at an X-ray intensity of 1 × 10(14) photons/mm(2) or less, all the produced electrons escaped from the target. However, above an X-ray intensity of 1 × 10(15) photons/mm(2) and an energy of 560 eV, some photoelectrons that were ejected from the oxygen atoms were trapped near the target DNA. CONCLUSIONS: A simulation method for studying the trajectories of electrons ejected from a 30-bp DNA molecule irradiated with pulsed monochromatic X-rays has been developed. The present results show that electron dynamics are strongly dependent on the charged density induced in DNA by pulsed X-ray irradiation.

A possible overestimation of the effect of acetylation on lysine residues in KQ mutant analysis.

Acetylation of lysine residues, one of the most common protein post-transcriptional modifications, is thought to regulate protein affinity with other proteins or nucleotides. Experimentally, the effects of acetylation have been studied using recombinant mutants in which lysine residues (K) are substituted with glutamine (Q) as a mimic of acetyl lysine (KQ mutant), or with arginine (R) as a mimic of nonacetylated lysine (KR mutant). These substitutions, however, have not been properly validated. The effects lysine acetylation on Ku, a multifunctional protein that has been primarily implicated in DNA repair and cell survival, are characterized herein using a series of computer simulations. The binding free energy was reduced in the KQ mutant, while the KR mutant had no effect, which is consistent with previous experimental results. Unexpectedly, the binding energy between Ku and DNA was maintained at almost the same level as in the wild type protein despite full acetylation of the lysine residues. These results suggest that the effects of acetylation may be overestimated when the KQ mutant is used as a mimic of the acetylated protein.

Enhanced resolution of molecular recognition to distinguish structurally similar molecules by different conformational responses of a protein upon ligand binding.

MutT distinguishes substrate 8-oxo-dGTP from dGTP and also 8-oxo-dGMP from dGMP despite small differences of chemical structures between them. In this paper we show by the method of molecular dynamics simulation that the transition between conformational substates of MutT is a key mechanism for a high-resolution molecular recognition of the differences between the very similar chemical compounds. (1) The native state MutT has two conformational substates with similar free energies, each characterized by either open or closed of two loops surrounding the substrate binding active site. Between the two substates, the open substate is more stable in free MutT and in dGMP-MutT complex, and the closed substate is more stable in 8-oxo-dGMP-MutT complex. (2) Conformational fluctuation of the open substate is much larger than that of the closed substate. An estimate of associated entropy difference was found to be consistent with the experimentally found difference of entropy contribution to the binding free energies of the two molecules. (3) A hydrogen bond between H7 atom of 8-oxo-dGMP and the sidechain of Asn119 plays a crucial role for maintaining the closed substate in 8-oxo-dGMP-MutT complex. When this hydrogen bond is absent in the H7-deficient dGMP-MutT complex, the closed substate is no more maintained and transition to the more entropically-favored open substate is induced. (4) Thus, this mechanism of the hydrogen bond controlling the relative stabilities of the drastically different two conformational substates enhances the resolution to recognize the small difference of the chemical structures between the two molecules, dGMP and 8-oxo-dGMP.

Stereoselective construction of substituted chromans by palladium-catalyzed cyclization of propargylic carbonates with 2-(2-hydroxyphenyl)acetates.

Highly substituted chromans have been constructed in a highly stereoselective manner by a palladium-catalyzed reaction of propargylic carbonates with 2-(2-hydroxyphenyl)acetates. Enantioselective reactions also successfully proceeded to give the optically active chromans with high enantioselectivity.

[Hypertension with tachycardia caused by propofol during induction of general anesthesia].

A 75-year-old man underwent elective posterior lumbar interbody fusion due to canal stenosis. Anesthesia was induced with fentanyl 100 microg, propofol 65 mg (0.95 mg x kg(-1)) and vecronium 7 mg. Bag and mask ventilation was easy and end-tidal sevoflurane reached 3% but arterial blood pressure (ABP) and heart rate (HR) increased to 180-200/90-110 mmHg and 90-110 beats x min(-1) respectively. Additional fentanyl 100 microg and propofol 70 mg were not effective. N2O was started and fentanyl 50 microg and landiolol 5 mg were administerd. Twenty-five minutes after initiation of anesthesia, ABP and HR decreased to 123/76 mmHg and 83 beats x min(-1), respectively. When right ureteral dilatation was undertaken due to obstruction on POD 7, thiamylal 300 mg for anesthetic induction did not increase ABP and HR. Hypertension with tachycardia during induction of general anesthesia can be usually caused by pain, hypoventilation, intracranial hemorrhage and myocardial ischemia etc but all of them were denied in this clinical course. Previous reports had shown that a small amount of propofol itself induced vasoconstriction and we concluded that a low dose of propofol to avoid hypotension during induction could cause hypertension with tachycardia.

[Efficacy and safety of AirWay Scope in using a bronchofiberscope in patients with difficult airway].

Case 1: A 41-year-old woman was scheduled for pinning of fractured finger and repair of a ligamentum. Preoperative problems did not exist except mandibular hypoplasia. General anesthesia was induced and Cormack classification was grade III in laryngeal view by laryngoscope and we tried a new videolaryngoscope PENTAX-AirWay Scope (AWS). We did not catch the epiglottis directly by Intlock and the target mark was not located at the middle of the vocal cord. Bronchofiberscope was guided to the vocal cord through a tracheal tube attached to AWS by another anesthesiologist and the patient was successfully intubated. Case 2: A 46-year-old man was scheduled for anterior screw-plate fixation due to C3/4 herniated disc. AWS using bronchofiberscope procedure was tried to keep the neutral position of the neck. The patient was successfully intubated. We did not view the bronchofiberscope and used it just as a flexible bougie. Case 3: A 56-year-old man was scheduled for free radial forearm flap reconstruction of a diabetic necrotic toe. Ten minutes were needed to finish intubation due to difficult airway (Cormack classification grade III) when free latissimus dorsi flap reconstruction was perfomed two month before. Hence, AWS using a bronchofiberscope procedure was tried first and 39 seconds were needed to intubate. We concluded that AWS using bronchofiberscope procedure was useful for patients with difficult airway, though two anesthesiologist, one keeping AWS and the other using a bronchofiberscope, were needed.

[Patients hospitalized the day before operation are satisfied with outpatient preoperative evaluation system].

BACKGROUND: Recently, shortening of hospitalization has increased the number of hospitalization the day before operation in Japan. Appropriate preoperative anesthetic evaluation systems should be developed to maintain the same quality and efficiency of evaluation as for patients hospitalized earlier. Patient satisfaction is an important consideration in this program. METHODS: We adopted an outpatient preoperative evaluation system for patients hospitalized the day before operation, using an original anesthesia application form, from November 2006. Forms containing multiple-choice questions regarding medical history and medications were completed by patients' doctors and submitted to us before evaluation. We examined the system use each month and conducted a survey using questionnaires on patient satisfaction in 42 patients using the system 8 months after its introduction. RESULTS: The proportion of patients using the system among surgical patients increased from 8.9% to 45.2% in half a year. The application form yielded detailed information efficiently and enabled sufficient preoperative management. In the questionnaire survey, 94.1% of the patients were satisfied with our new system due to early understanding and anxiety reduction, reduction of burden after hospitalization, and appropriate preoperative management. CONCLUSIONS: Our new system enabled improvement in quality and efficiency of perioperative management and increase in patient satisfaction in preoperative evaluation for hospitalization the day before operation.

[Angle-closure glaucoma: important points in the diagnosis and follow-up].

A 74-year-old woman visited her local physician complaining of fever, cough, headache, hyperemic left conjunctiva, and blurred vision. She was diagnosed as having common cold and medicated for it, and later, she visited our department. She had a shallow left anterior chamber with moderately dilated pupil. Gonioscopic examination of the left eye revealed a narrow angle corresponding to grade 1 by Shaffer grading system. Left intraocular pressure was 16 mmHg. She was diagnosed to have had a spontaneous recovery from a subacute attack of angle-closure glaucoma. Laser iridectomy was performed and she was put on a regular ophthalmological follow-up. Three years later, she experienced an attack of left angle-closure glaucoma secondary to lens intumescence. She was treated by phacoemulsification and aspitaion which resulted in the eventual cure.