Cellular nicotinamide adenine dinucleotide (NADH) as an indicator of bacterial metabolic activity dynamics in activated sludge.

In this study, native fluorescent nicotinamide adenine dinucleotide (NADH) was used as a direct indicator of bacterial metabolic activity in activated sludge. Specific NADH concentration was dynamic and varied between 10(6)-10(8) molecules per bacterial cell. Low concentrations (10(6)-10(7) NADH molecules cell(-1)) indicate efficient bacterial metabolic activity while high concentrations (10(7)-10(8) NADH molecules cell(-1)) indicate inefficient bacterial metabolic activity. Specific [NADH] did not correlate to changes in dissolved organic carbon, but increases correlated to decreases in oxygen uptake rates. Perhaps a lack of oxygen as the terminal electron acceptor prevented efficient reoxidization of NADH to NAD+, which resulted in an accumulation of NADH within the cells. Also, significant amounts of NADH were released and accumulated into the extracellular medium of metabolically active E. coli cells in log phase. Such overflow metabolism may be the product of favourable conditions. Thus, the flux of both specific intracellular and extracellular [NADH] indicates the dynamics of bacterial metabolic activity in activated sludge.

Deficiency of cyclooxygenases transcripts in cultured primary bronchial epithelial cells of aspirin-sensitive asthmatics.

BACKGROUND: Airway function is actively regulated by epithelium through generating PGE(2), the production of which depends on cyclooxygeneses (COX-1 and COX-2). Analysis of bronchial biopsies and bronchial epithelial cells in culture conducted so far gave conflicting results of expression pattern of these enzymes in healthy subjects and asthmatics patients, with and without aspirin hypersensitivity. OBJECTIVE: Our aim was to investigate the expression of COX-1 and COX-2 mRNA in primary human bronchial epithelial cells (HBEC) isolated from asthmatics and non-asthmatics. METHODS: We isolated HBEC from bronchial brushing preparations taken during bronchoscopy of 10 non-asthmatics (NA), 8 aspirin-tolerant asthmatics (ATA) and 9 aspirin-intolerant asthmatics (AIA). HBEC were cultured in serum free medium until 80% confluent. Total cellular RNA was isolated and reversed transcribed using oligo(dT)(15) primers. Real time PCR was performed with primers to COX-1, COX-2, GAPDH and beta-actin in the presence of SYBR green dye. The cycle threshold (C(T)) for COX-1 or COX-2 was normalized using beta-actin and GAPDH as the internal standards. RESULTS: Not only COX-1 but also COX-2 mRNA were expressed by HBEC without any proinflammatory stimulation. We detected the smallest amount of COX-1 mRNA in the AIA group. The same trend was observed for COX-2 mRNA, though it didn't reach the statistical significance. We also analysed the relationship between DeltaC(TCOX-1) to DeltaC(TCOX-2) by calculating the difference DeltaDeltaC(TCOX-1-COX-2). This analysis revealed that AIA group can be characterized by relatively smallest COX-1 mRNA expression in comparison to COX-2. There is a strong positive correlation between C(TCOX1) and C(TCOX2) in NA group (r=0.85; p< 0.001). In both groups of asthmatics this correlation is absent (ATA - r=0.5, p>0.1; AIA - r=0.43, p>0.1). CONCLUSIONS: Cyclooxygeneases transcripts expression is altered in HBEC derived from the asthmatic patients, and this phenomenon is pronounced in case of aspirin hypersensitivity.

[Vertical pathological attrition--causes, consequences and treatment methods]. / Starcie patologiczne pionowe--przyczyny, konsekwencje oraz metody leczenia.

The mechanism of development of vertical pathological attrition leading to destruction of the palatine and vestibular surfaces of the anterior teeth is described. Vertical pathological attrition is most frequent in acquired occlusal defects after loss of abutement zones, and in certain congenital malocclusions (supraocclusion). This condition may lead to damage to the whole stomatognathic system. Depending on the degree of progression of the pathological changes of this system prosthetic treatment in cases of vertical pathological attrition may be done in one or two steps. For illustration of the methods of treatment of this attrition three cases are presented.