Evaluation of microplastic pollution in a lotic ecosystem and its ecological risk.

This study investigates the microplastics (MPs) pollution in Tigris River, assessing spatial and temporal variations in water and sediment. MPs presence was high during both seasons 3429.2 MPs/m3 (dry season) and 3363.2 MPs/m3 (wet season) in water, and 121.2 MPs/kg (wet season) and 123.2 MPs/kg (dry season) in sediment. MPs morphology mostly consisted of fibers and fragments, with sizes below 0.5 mm. Transparent and white were the most common colors, and they were primarily composed of polyethylene (PE) and polypropylene (PP). Ecological risk assessment, using the plastic hazard index (PHI), pollution load index (PLI), and potential ecological risk index (PERI), categorized the risk from danger to extreme danger based on PHI, while PLI and PERI indicated a minor risk. These findings provide initial evidence of microplastics pollution in the Tigris River's water and sediment, emphasizing the need for action by decision-makers to mitigate these risks.

Effect of rapid maxillary expansion on monosymptomatic primary nocturnal enuresis.

OBJECTIVE: To evaluate the effects of rapid maxillary expansion (RME) on nocturnal enuresis (NE) related to the nasal airway, nasal breathing, and plasma osmolality (as an indicator for antidiuretic hormone). MATERIALS AND METHODS: Nineteen patients with monosymptomatic primary NE, aged 6-15 years, were treated with RME for 10-15 days. To exclude a placebo effect of the RME appliance, seven patients were first treated with a passive appliance. Computed tomography of nasal cavity, rhinomanometric, and plasma osmolality measurements were made 2-3 days before and 2-3 months after the RME period. RME effects on NE were followed for three more years. RESULTS: Two to three months after the expansion there were significant improvements in the breathing function and a decrease in the plasma osmolality. NE decreased significantly in all patients after the RME period, and all patients showed full dryness after 3 years. CONCLUSIONS: This study demonstrates that RME causes complete dryness in all patients, with significant effects on pathophysiological mechanisms related to NE.

Characterization of intestinal bacteria tightly bound to the human ileal epithelium.

In order to perform selective isolation of bacteria tightly bound to the human gut, ileal biopsies of healthy volunteers were treated to wash out the mucus layer and loosely bound bacterial cells. Rod-shaped anaerobic bacteria that had remained attached to the epithelial cells were isolated and identified at the species level. One isolate was identified as belonging to the Bifidobacterium breve species, while all the others were lactobacilli of only two species, Lactobacillus mucosae and Lactobacillus gasseri. Members of these species were found previously in intestinal samples, but their predominance among bacteria strictly associated with the epithelium was not suspected before and suggests that these species may represent a specific subpopulation of tissue-bound bacteria. Physiological analysis indicated that all isolates were able to produce antimicrobials, grow and form biofilm in simulated intestinal fluid after exposure to gastric conditions. Some isolates were able to degrade mucin while none showed cytotoxicity in vitro on HT29 cells. The tight association of the strains isolated with ileal epithelial cells is presumably indicative of a direct interaction with the host cells. For this reason and for the absence of cytotoxicity in vitro, those isolates can be proposed as potential probiotic strains for human use.

Defining the natural habitat of Bacillus spore-formers.

Our understanding of the genetics and physiology of the spore-forming genus Bacillus is remarkable. On the other hand, though, where these Gram-positive bacteria live and grow is far from clear. The soil, once considered their habitat, may simply serve as a reservoir. A growing number of studies show that Bacillus spores can be found in the intestinal tracts of animals, raising the question of whether this could be where they live and grow. In this study, we have conducted the first evaluation of Bacillus spore formers in soil and in human faeces. Our aim is simply to determine the abundance of aerobic spore-formers. Our results show that soil carries approximately approximately 10(6)spores/g while human faeces an average of up to 10(4)spores/g. The numbers of spores found in faeces, we reason, is too high to be accounted for principally by ingestion of food contaminated with spores from soil. This provides further evidence that Bacillus spore formers may have adapted to survival within the intestinal tract of insects and other animals that ingest them; if so they may well be hitherto undiscovered gut commensals.