Swallowing and aspiration during sleep in patients with obstructive sleep apnea versus control individuals.

STUDY OBJECTIVES: There are only a few reports on voluntary swallowing during sleep; therefore, this study aimed to propose a method for observing voluntary swallowing during sleep using polysomnography. The frequency of voluntary swallowing during sleep and the factors related to swallowing and aspiration during sleep were investigated. METHODS: Polysomnography records of 20 control subjects and 60 patients with obstructive sleep apnea (OSA) (mild, moderate, and severe groups; n = 20 each) were collected. Simultaneous increases in the electromyographic potentials of the submental and masseter muscles, termed coactivation, and declining oronasal airflow (SA) were extracted as "swallowing." The cough reflex that occurred during sleep was extracted as "aspiration." The frequency of swallowing events was compared among the different OSA severity groups. Subsequently, a multivariate regression analysis was performed. RESULTS: The average frequency of coactivation with SA in control subjects was 4.1 events/h and that without SA was 1.7 events/h. These frequencies increased with the severity of OSA during non-REM sleep. The distance of the hyoid to the Frankfurt plane was associated with the frequency of coactivation with (ß = 0.298, p = 0.017) as well as without SA (ß = 0.271, p = 0.038). The frequency of coactivation without SA was associated with aspiration (B = 0.192, p = 0.042). CONCLUSIONS: Our data provide new insights into the relationship between swallowing and aspiration during sleep. We found that the longer the distance from the hyoid bone to the Frankfurt plane, the higher the coactivation without SA, which could lead to aspiration during sleep. CLINICAL TRIALS: Retrospective observational study of swallowing during sleep in obstructive sleep apnea patients using polysomnography, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000050460, UMIN000044187.

Impact of continuous positive airway pressure therapy for nonalcoholic fatty liver disease in patients with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) has been suggested as an independent risk factor for nonalcoholic fatty liver disease (NAFLD), and continuous positive airway pressure (CPAP) is the first-line therapy for OSA. AIM: To clarify the efficacy of effective CPAP therapy on NAFLD of OSA patients by serum markers and transient elastography (TE) using FibroScan® (Echosens, Paris, France). METHODS: We prospectively enrolled 123 consecutive patients with OSA who met the indications for CPAP. Liver fibrosis and steatosis were assessed using TE. Before and after 6 mo of CPAP therapy, serum markers and TE were assessed for all patients. The mean usage rate of CPAP therapy for 6 mo was arbitrarily calculated in each patient and expressed as "mean compliance index" (m-CI). RESULTS: In 50 OSA patients with NAFLD, both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were significantly decreased after 6 mo of CPAP therapy. Univariate analysis showed that decreased body weight (BW), decreased body mass index (BMI), decreased AST level, decreased hemoglobin A1c, and high m-CI were significantly related with improved ALT level. In multivariate regression model adjusted for quantities of BW change during 6 mo of CPAP therapy, high m-CI tended to improve ALT level (P = 0.051). All 17 OSA patients with NAFLD, high m-CI and no BMI changes showed significant improvements in AST and ALT levels. Meanwhile, no significant changes in TE data or serum fibrosis markers were seen. CONCLUSION: Some NAFLD could be associated with chronic intermittent hypoxia due to OSA independent of BW changes. In those cases, adequate reoxygenation from effective CPAP therapy may improve NAFLD.

Pathological findings of myocardium in a patient with cardiac conduction defect associated with an SCN5A mutation.

A 16-year-old Japanese man was admitted to our hospital because of syncope during exercise. His father and his younger brother had permanent pacemaker implantation because of sick sinus syndrome. Several examinations revealed first-degree atrioventricular block, complete right bundle branch block, sick sinus syndrome, and ventricular tachycardia with normal cardiac function. As no abnormalities were evident on coronary angiography, right ventricular endomyocardial biopsy was performed. It showed myocardial disarrangement and lipofuscin accumulation in hypertrophic myocytes. Moreover, electron microscopy showed a few degenerative myocytes, Z-band streaming, disarrangement, increased small capillaries with Weibel-Palade bodies in endothelial cells, and endothelial proliferations. Genetic analysis of the proband, his father, and his younger brother revealed a missense mutation, D1275N, in SCN5A, a gene which encodes sodium ion channel protein, are related to cardiomyopathy and arrhythmia. The proband was diagnosed with a cardiac conduction defect (CCD) and underwent permanent pacemaker implantation. These pathological findings suggest various myocardial changes presented in CCD patients with a missense mutation, D1275N, in SCN5A.

Molecular analysis of cyclic α-maltosyl-(1→6)-maltose binding protein in the bacterial metabolic pathway.

Cyclic α-maltosyl-(1→6)-maltose (CMM) is a cyclic glucotetrasaccharide with alternating α-1,4 and α-1,6 linkages. Here, we report functional and structural analyses on CMM-binding protein (CMMBP), which is a substrate-binding protein (SBP) of an ABC importer system of the bacteria Arthrobacter globiformis. Isothermal titration calorimetry analysis revealed that CMMBP specifically bound to CMM with a Kd value of 9.6 nM. The crystal structure of CMMBP was determined at a resolution of 1.47 Å, and a panose molecule was bound in a cleft between two domains. To delineate its structural features, the crystal structure of CMMBP was compared with other SBPs specific for carbohydrates, such as cyclic α-nigerosyl-(1→6)-nigerose and cyclodextrins. These results indicate that A. globiformis has a unique metabolic pathway specialized for CMM.

Structural features of a bacterial cyclic α-maltosyl-(1→6)-maltose (CMM) hydrolase critical for CMM recognition and hydrolysis.

Cyclic α-maltosyl-(1→6)-maltose (CMM, cyclo-{→6)-α-d-Glcp-(1→4)-α-d-Glcp-(1→6)-α-d-Glcp-(1→4)-α-d-Glcp-(1→})is a cyclic glucotetrasaccharide with alternating α-1,4 and α-1,6 linkages. CMM is composed of two maltose units and is one of the smallest cyclic glucooligosaccharides. Although CMM is resistant to usual amylases, it is efficiently hydrolyzed by CMM hydrolase (CMMase), belonging to subfamily 20 of glycoside hydrolase family 13 (GH13_20). Here, we determined the ligand-free crystal structure of CMMase from the soil-associated bacterium Arthrobacter globiformis and its structures in complex with maltose, panose, and CMM to elucidate the structural basis of substrate recognition by CMMase. The structures disclosed that although the monomer structure consists of three domains commonly adopted by GH13 and other α-amylase-related enzymes, CMMase forms a unique wing-like dimer structure. The complex structure with CMM revealed four specific subsites, namely -3', -2, -1, and +1'. We also observed that the bound CMM molecule adopts a low-energy conformer compared with the X-ray structure of a single CMM crystal, also determined here. Comparison of the CMMase active site with those in other enzymes of the GH13_20 family revealed that three regions forming the wall of the cleft, denoted PYF (Pro-203/Tyr-204/Phe-205), CS (Cys-163/Ser-164), and Y (Tyr-168), are present only in CMMase and are involved in CMM recognition. Combinations of multiple substitutions in these regions markedly decreased the activity toward CMM, indicating that the specificity for this cyclic tetrasaccharide is supported by the entire shape of the pocket. In summary, our work uncovers the mechanistic basis for the highly specific interactions of CMMase with its substrate CMM.

Human Lipocalin-Type Prostaglandin D Synthase-Based Drug Delivery System for Poorly Water-Soluble Anti-Cancer Drug SN-38.

Lipocalin-type prostaglandin D synthase (L-PGDS) is a member of the lipocalin superfamily, which is composed of secretory transporter proteins, and binds a wide variety of small hydrophobic molecules. Using this function, we have reported the feasibility of using L-PGDS as a novel drug delivery vehicle for poorly water-soluble drugs. In this study, we show the development of a drug delivery system using L-PGDS, one that enables the direct clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), a poorly water-soluble anti-cancer drug. In the presence of 2 mM L-PGDS, the concentration of SN-38 in PBS increased 1,130-fold as compared with that in PBS. Calorimetric experiments revealed that L-PGDS bound SN-38 at a molecular ratio of 1:3 with a dissociation constant value of 60 µM. The results of an in vitro growth inhibition assay revealed that the SN-38/L-PGDS complexes showed high anti-tumor activity against 3 human cancer cell lines, i.e., Colo201, MDA-MB-231, and PC-3 with a potency similar to that of SN-38 used alone. The intravenous administration of SN-38/L-PGDS complexes to mice bearing Colo201 tumors showed a pronounced anti-tumor effect. Intestinal mucositis, which is one of the side effects of this drug, was not observed in mice administered SN-38/L-PGDS complexes. Taken together, L-PGDS enables the direct usage of SN-38 with reduced side effects.

[A Case of Undiagnosed Extra-adrenal Pheochromocytoma in an Adult Patient with Single Ventricle Circulation after the Bidirectional Glenn Operation].

We experienced a case of undiagnosed extra-adrenal pheochromocytoma in an adult patient with single ventricle circulation after the bidirectional Glenn operation. A 32-year-old woman was scheduled for open abdominal surgery for incidental retroperitoneal tumor. She had undergone the bidirectional Glenn operation for complex congenital heart disease consisting of double outlet right ventricle, ventricular septal defect, and pulmonary artery stenosis. She had not undergone the Fontan operation because of insufficient development of pulmonary circulation. Her physical status was New York Heart Association (NYHA) functional class II, and her oxygen saturation was 80% in room air. She reported no symptoms for the abdominal tumor preoperatively. The surgery was performed under general and epidural anesthesia. After induction of general anesthesia, she developed hypertension and tachycardia, and the manipulation of the tumor worsened them. Landiolol, a short acting beta blocker, and nicardipine were administrated. After the resection of the tumor, hypotension refractory to volume replacement emerged, and we administrated low dose noradrenaline. She was extubated in'the operating room and was transferred to the intensive care unit. The histopathological examination of the tumor revealed extra-adrenal pheochromocytoma (paraganglioma). Catecholamine release from pheochromocytoma can be dangerous in patients with single ventricular circulation because it may elevate pulmonary resistance and thereby decrease cardiac output. Thorough preoperative examination is desirable.

Metal-mediated oxidative DNA damage induced by methylene blue.

BACKGROUND: Methylene blue (MB) is used for various clinical purposes, including chromoendoscopy and methemoglobinemia treatment. However, MB induces tumors of pancreatic islets and small intestine in experimental animals. This finding raises a possibility that MB induces carcinogenicity in these organs via light-independent mechanisms, although MB is known to cause light-dependent DNA damage. METHODS: We investigated the mechanism of MB-induced DNA damage using (32)P-5'-end-labeled DNA fragments of human tumor-relevant genes. We investigated the redox reaction of MB by UV-visible spectrometry. RESULTS: MB induced DNA damage at the 5'-ACG-3' sequence, a hot spot of the p53 gene, in the presence of NADH and Cu(II). DNA damage was inhibited by catalase and bathocuproine, a Cu(I)-specific chelator. MB induced DNA damage at every nucleotide in the presence of NADH and Fe(III)-ethylenediaminetetraacetic acid, which was inhibited by OH scavengers and catalase. MB significantly increased the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine, an oxidative DNA lesion, in the presence of NADH and metal ions. UV-visible spectrometry revealed that the absorbance of oxidized form of MB at 668nm was decreased by NADH, and the addition of metal ions attenuated the spectral change. CONCLUSIONS: MB undergoes NADH-dependent reduction followed by metal ion-mediated reoxidation. Reduced metal ions [Cu(I) and Fe(II)] interact with H2O2, generated during the redox reaction, to produce Cu(I)OOH and OH that cause DNA damage, respectively. These findings suggest that metal-mediated DNA damage contributes to MB-mediated carcinogenesis. GENERAL SIGNIFICANCE: This study would provide an insight into the mechanism of MB-induced carcinogenesis and its safety assurance for clinical use.

Sodium channelopathy underlying familial sick sinus syndrome with early onset and predominantly male characteristics.

BACKGROUND: Sick sinus syndrome (SSS) is a common arrhythmia often associated with aging or organic heart diseases but may also occur in a familial form with a variable mode of inheritance. Despite the identification of causative genes, including cardiac Na channel (SCN5A), the pathogenesis and molecular epidemiology of familial SSS remain undetermined primarily because of its rarity. METHODS AND RESULTS: We genetically screened 48 members of 15 SSS families for mutations in several candidate genes and determined the functional properties of mutant Na channels using whole-cell patch clamping. We identified 6 SCN5A mutations including a compound heterozygous mutation. Heterologously expressed mutant Na channels showed loss-of-function properties of reduced or no Na current density in conjunction with gating modulations. Among 19 family members with SCN5A mutations, QT prolongation and Brugada syndrome were associated in 4 and 2 individuals, respectively. Age of onset in probands carrying SCN5A mutations was significantly less (mean±SE, 12.4±4.6 years; n=5) than in SCN5A-negative probands (47.0±4.6 years; n=10; P<0.001) or nonfamilial SSS (74.3±0.4 years; n=538; P<0.001). Meta-analysis of SSS probands carrying SCN5A mutations (n=29) indicated profound male predominance (79.3%) resembling Brugada syndrome but with a considerably earlier age of onset (20.9±3.4 years). CONCLUSIONS: The notable pathophysiological overlap between familial SSS and Na channelopathy indicates that familial SSS with SCN5A mutations may represent a subset of cardiac Na channelopathy with strong male predominance and early clinical manifestations.

Simultaneous laparoscopic hand-assisted hepatectomy and splenectomy for liver cancer with hypersplenism: report of a case.

Hepatocellular carcinoma accompanied by portal hypertension and hypersplenism is difficult to treat medically and surgically due to pancytopenia and the development of collateral circulation. In this study, we were able to safely and simultaneously perform a laparoscopically-assisted splenectomy and partial hepatectomy. The characteristics of this procedure include: (1) the shared use of a medial wound made through laparoscopically-assisted surgery; (2) improved safety for manipulating areas that were difficult to observe with a camera in a case of splenomegaly; (3) a preventive ligation of the splenic artery; (4) improved hemostatic function using LigaSure Impact; and (5) hemorrhage control through manual manipulations and the Pringle maneuver during liver parenchymal transection. The surgery was safely performed using the above points.

Demographic characteristics of 3,659 Japanese patients with obstructive sleep apnea-hypopnea syndrome diagnosed by full polysomnography: associations with apnea-hypopnea index.

Information on obstructive sleep apnea-hypopnea syndrome (OSAHS) in Japan has been limited. The purposes of this clinical study were to evaluate the demographic characteristics of Japanese OSAHS patients and to assess how demographic factors are associated with OSAHS severity. We analyzed 3,659 OSAHS patients who underwent polysomnographic evaluation between January 2000 and December 2004 at 11 hospitals in Niigata Prefecture, Japan. Data consisted of apnea-hypopnea index (AHI) and demographic characteristics, including sex, age, and body-mass index, for statistical analysis. Levels of obesity were classified according to the WHO criteria. The male-to-female patient ratio for OSAHS was 4.6, and male patients presented more severe OSAHS than female patients. High AHI and a high proportion of moderate to serious OSAHS (AHI > or = 15) were found among the patients in their 30s, as well as female patients in their 70s and male patients in their 80s. The AHI and the proportion of moderate-to-serious OSAHS (AHI > or = 15) were greater in patients classified as underweight than in normal weight patients. In conclusion, there is a higher male predominance in the prevalence of OSAHS, and in both sexes, the results suggest different pathophysiological mechanisms of deteriorating OSAHS between adults under age 55 and adults 55 years or over. In addition, underweight patients exhibit more severe OSAHS than normal weight patients.