[2nd place in the contest for young scientists on gastroenterology in the 17th Congress "Man and Medicine" (April 2010, Moscow). Erosive esophagitis in children: characteristics of 24-hour pH monitoring in the the esophagus].
To evaluate the energy metabolism of peripheral skeletal muscle during exercise in patients with chronic respiratory impairment, the 31P-nuclear magnetic resonance (NMR) spectra of forearm muscle were investigated in nine patients and nine age-matched control subjects. We calculated the phosphocreatine (PCr) to PCr + inorganic phosphate (PI) ratio, the time constant of PCr recovery and the intracellular pH. The exercise consisted of repetitive hand grips against a 2-kg load every 3 s for 6 min (0.33 W). The patients showed a marked decrease in the PCr/(PCr + PI) ratio and pH in the muscle during exercise in contrast to the control subjects whose PCr/(PCr + PI) showed a minor decrease without any change in pH. The relationship between PCr utilization and pH demonstrated that anaerobic glycolysis switched on earlier in patients with chronic respiratory impairment. A split PI peak was observed in five of nine patients during exercise. The PCr/(PCr + PI) ratio during the last minute of exercise correlated significantly with the vital capacity (% predicted), with the FEV1/FVC, with the body weight, with the maximum strength of hand grip, and with the muscle mass. The results indicate impaired oxidative phosphorylation and the early activation of anaerobic glycolysis in the muscles of patients with chronic respiratory impairment. Several factors related to chronic respiratory impairment, such as disuse, malnutrition and dysoxia, would contribute to the metabolic changes observed in the muscles examined.
Abnormal glycosylation of cellular glycoconjugates is a common phenotypic change in many human tumors. Here, we explore the possibility that an altered Golgi pH may also be responsible for these cancer-associated glycosylation abnormalities. We show that a mere dissipation of the acidic Golgi pH results both in increased expression of some cancer-associated carbohydrate antigens and in structural disorganization of the Golgi apparatus in otherwise normally glycosylating cells. pH dependence of these alterations was confirmed by showing that an acidification-defective breast cancer cell line (MCF-7) also displayed a fragmented Golgi apparatus, whereas the Golgi apparatus was structurally normal in its acidification-competent subline (MCF-7/AdrR). Acidification competence was also found to rescue normal glycosylation potential in MCF-7/AdrR cells. Finally, we show that abnormal glycosylation is also accompanied by similar structural disorganization and fragmentation of the Golgi apparatus in colorectal cancer cells in vitro and in vivo. These results suggest that an inappropriate Golgi pH may indeed be responsible for the abnormal Golgi structure and lowered glycosylation potential of the Golgi apparatus in malignant cells.
We assessed changes in skeletal muscle energy metabolism by 31P-magnetic resonance spectroscopy (31P-MRS) and oxygen supply by near-infrared spectroscopy (NIR), after exercise and after administration of glucose and a branched-chain amino acids (BCAA), in healthy volunteers and patients with liver cirrhosis. As for the patients with liver cirrhosis, 4 were classified in Child-Pugh Grade A and the other 4 in Grade B. In patients with liver cirrhosis, the intramuscular pH and PCr index (PCr/PCr + Pi) were lower than in healthy subjects after exercise in the fasting state; the deltapH and deltaPCr index were statistically siginificant (p
Numeric abundance, identity and pH preferences of methanotrophic Gammaproteobacteria (type I methanotrophs) inhabiting the northern acidic wetlands were studied. The rates of methane oxidation by peat samples from six-wetlands of European Northern Russia (pH 3.9-4.7) varied from 0.04 to 0.60 µg CH4 g(-1) peat h(-1). The number of cells revealed by hybridization with fluorochrome-labeled probes M84 + M705 specific for type I methanotrophs was 0.05-2.16 x 10(5) cells g(-1) dry peat, i.e. 0.4-12.5% of the total number of methanotrophs and 0.004-0.39% of the total number of bacteria. Analysis of the fragments of the pmoA gene encoding particulate methane monooxygenase revealed predominance of the genus Methylocystis (92% of the clones) in the studied sample of acidic peat, while the proportion of the pmoA sequences of type I methanotrophs was insignificant (8%). PCR amplification of the 16S rRNA gene fragments of type I methanotrophs with TypeIF-Type IR primers had low specificity, since only three sequences out of 53 analyzed belonged to methanotrophs and exhibited 93-99% similarity to those of Methylovulum, Methylomonas, and Methylobacter species. Isolates of type I methanotrophs obtained from peat (strains SH10 and 83A5) were identified as members of the species Methylomonaspaludis and Methylovulum miyakonense, respectively. Only Methylomonaspaludum SH10 was capable of growth in acidic media (pH range for growth 3.8-7.2 with the optimum at pH 5.8-6.2), while Methylovulum miyakonense 83A5 exhibited the typical growth characteristics of neutrophilic methanotrophs (pH range for growth 5.5-8.0 with the optimum at pH 6.5-7.5).
OBJECTIVE: Evaluate obstetric characteristics during the last two hours of labor in neonates born with acidemia. DESIGN: Case-control study. SETTING: Delivery units at two university hospitals in Sweden. STUDY POPULATION: Out of 28,486 deliveries during 1994-2004, 305 neonates had an umbilical artery pH value or = 7.05 and an Apgar score > or =7 at 5 minutes. Obstetric characteristics, cardiotocographic patterns and oxytocin treatment during the last two hours of labor were recorded. RESULTS: In the univariate analysis, > or =6 contractions/10 minutes (odds ratio (OR) 4.94, 95% confidence interval (CI) 3.25-7.49), oxytocin use (OR 2.20, 95% CI 1.66-2.92), bearing down > or =45 minutes (OR 1.77, 95% CI 1.31-2.38) and occipito-posterior position (OR 2.18, 95% CI 1.19-3.98) were associated with acidemia at birth. In the multivariate analysis, only > or =6 contractions/10 minutes (OR 5.36, 95% CI 3.32-8.65) and oxytocin use (OR 1.89, 95% CI 1.21-2.97) were associated with acidemia at birth. Among cases with > or =6 contractions/10 minutes, 75% had been treated with oxytocin. Pathological cardiotocographic patterns occurred in 68.8% of cases and in 26.1% of controls (p
Acid precipitation affects the solubility of several metals in aquatic systems and in soil. Cadmium levels in tap water samples from geological areas having low resistance to acidic pollution were significantly higher than those in samples from a neighbouring reference area where there was a different geological structure. The median cadmium levels and pH values were 0.14 microgram l-1 and 5.6 respectively, for the acidic areas compared with 0.07 microgram l-1 and 6.4 respectively for the reference area. Further, there was a significant inverse relationship between both cadmium and lead contents and the pH values of the samples. The mobility of the metals was thus dependent on the acidity. The blood lead levels in 195 subjects from the acidic areas were lower than those in 91 subjects from the reference area (medians 60 vs. 70 micrograms l-1); no significant differences were found in blood cadmium or blood mercury levels. Subjects in the acidic areas had lower plasma selenium levels than those from the reference area (medians 85 vs. 90 micrograms l-1); the difference was mainly attributed to subjects with private wells. The data may indicate a negative effect of the acidic pollution on selenium intake via water and/or foods. There was also a positive relationship between intake of fish on the one hand and blood mercury and plasma selenium on the other, which is in accordance with the role of fish as a source of these metals.
Ammonia emissions are a major problem associated with animal slurry management, and solutions to overcome this problem are required worldwide by farmers and stakeholders. An obvious way to minimize ammonia emissions from slurry is to decrease slurry pH by addition of acids or other substances. This solution has been used commonly since 2010 in countries such as Denmark, and its efficiency with regard to the minimization of NH3 emissions has been documented in many studies. Nevertheless, the impact of such treatment on other gaseous emissions during storage is not clear, since the studies performed so far have provided different scenarios. Similarly, the impact of the soil application of acidified slurry on plant production and diffuse pollution has been considered in several studies. Also, the impact of acidification upon combination with other slurry treatment technologies (e.g. mechanical separation, anaerobic digestion …) is important to consider. Here, a compilation and critical review of all these studies has been performed in order to fully understand the global impact of slurry acidification and assess the applicability of this treatment for slurry management.
To investigate whether distal esophageal acidification occurs during sleep in patients suspected of sleep-disordered breathing, and whether such acidification is related to respiratory abnormalities.
Fourteen middle-aged, snoring men all complaining of daytime sleepiness and suspected of having obstructive sleep apnea.
Sleep laboratory, Pulmonary Department, Landspitali University Hospital, Reykjavik, Iceland.
Each patient underwent full nocturnal polysomnography testing, which included continuous monitoring of esophageal pressure (Pes) and pH. We identified all pH events, which were defined as a reduction in esophageal pH of >/= 1.0. During each pH event, the respiratory recordings where examined for the presence of apneas or hypopneas, and Pes was recorded. The data were analyzed to determine the possible relationships between pH events and respiratory events, and between changes in pH and changes in Pes. We found that there were more respiratory events than pH events. The mean (+/- SD) number of apneas and hypopneas per hour of sleep was 33 +/- 22, whereas the mean number of pH events per hour of sleep was 7 +/- 6. Overall, 81% of all pH events were associated with respiratory events. Correlation analysis did not reveal any significant relationship between pH events and the magnitude of Pes or apnea-hypopnea index.
Episodes of esophageal acidification are common in patients with sleep apnea, and are usually associated with respiratory and pressure events. However, changes in pH were independent of the magnitude of the Pes.