Integrated non-invasive measurements reveal swallowing and respiration coordination recovery after unilateral stroke.

BACKGROUND: Oropharyngeal dysphagia is common after a stroke. Understanding the physiology of swallowing and its coordination with respiration in stroke recovery is crucially important. METHODS: A non-invasive swallowing assessment method was used to detect oropharyngeal swallowing and respiration coordination simultaneously during the swallowing process. This system detected movement of the larynx, submental muscle activity, and nasal airflow. Six different sizes of water boluses (maximum of 20 mL) were swallowed and assessed for each subject. KEY RESULTS: We recruited 59 healthy participants and 38 first ever unilateral stroke patients completed baseline and follow-up assessments at 3, 6, and 9 months poststroke. The results showed that oropharyngeal swallowing parameters in unilateral stroke deviate from normal patterns. For respiration coordination, the unilateral stroke group had longer swallowing apnea duration but similar frequencies of pre- and postswallowing respiratory phase patterns compared with the healthy controls. The probability of piece-meal deglutition was higher in the stroke group than in the control group. Additionally, there were gradually decreasing piece-meal deglutition probabilities among the stroke patients at follow-up, and none differed statistically from those of the controls at 6 months poststroke. CONCLUSIONS & INFERENCES: The non-invasive swallowing and respiration assessment method applied in this study detected the changes manifested in swallowing and respiration during the subacute phase of recovery in 6 months after a unilateral stroke. The study results serve as a baseline for further research and help advance dysphagia research methodologies. These assessments may be combined with bedside evaluations for clinical application.

Alterococcus agarolyticus, gen.nov., sp.nov., a halophilic thermophilic bacterium capable of agar degradation.

Five strains of facultatively anaerobic moderately thermophilic bacteria were isolated from two hot springs in the intertidal zone of Lutao, Taiwan. They produced extracellular agarase on agar medium, yielding reducing sugars and organic acids as the end products under either aerobic or anaerobic conditions. The growth temperature range was approximately 38-58 degrees C with an optimal temperature of about 48 degrees C. The five strains tolerated a relatively narrow pH range from 7.0 to 8.5. They were Gram-negative halophiles growing optimally at 2.0-2.5% NaCl (ca. 0.34-0.43 M). They were capable of anaerobic growth by fermenting glucose and producing various organic acids such as butyrate, propionate, formate, lactate, and acetate. Cells grown in liquid medium were motile monotrichous cocci, normally 0.8-0.9 micron in diameter. They possessed saturated anteiso-15-carbon acid (anteiso-C15:0) as the most abundant cellular fatty acid (46.0-51.3 mo1%) and had G + C contents ranging from 65.5 to 67.0 mo1%. They are the first thermophiles found to degrade agar and also the first halophilic thermophilic bacteria known to be capable of both aerobic and anaerobic fermentative growth. These bacteria are considered to represent a new genus that we named Alterococcus, and Alterococcus agarolyticus is the type species.

A Photobacterium-like bacterium able to fix nitrogen.

A Photobacterium-like bacterium isolated from the roots of eelgrass (Zostera marina) was shown to fix nitrogen under anaerobic conditions. Nitrogen fixation by Photobacterium spp. has not been reported previous to this.

Enumeration and characterization of nitrogen-fixing bacteria in an eelgrass (Zostera marina) bed.

Marine nitrogen-fixing bacteria distributed in the eelgrass bed and seawater of Aburatsubo Inlet, Kanagawa, Japan were investigated using anaerobic and microaerobic enrichment culture methods. The present enrichment culture methods are simple and efficient for enumeration and isolation of nitrogen-fixing bacteria from marine environments. Mostprobable-number (MPN) values obtained for nitrogen-fixing bacteria ranged from 1.1×10(2) to 4.6×10(2)/ml for seawater, 4.0×10(4) to 4.3×10(5)/g wet wt for eelgrass-bed sediment, and 2.1 × 10(5) to 1.2 × 10(7)/g wet wt for eelgrass-root samples. More than 100 strains of halophilic, nitrogen-fixing bacteria belonging to the family Vibrionaceae were isolated from the MPN tubes. These isolates were roughly classified into seven groups on the basis of their physiological and biochemical characteristics. The majority of the isolates were assigned to the genusVibrio and one group to the genusPhotobacterium. However, there was also a group that could not be identified to the generic level. All isolates expressed nitrogen fixation activities under anaerobic conditions, and no organic growth factors were required for their activities.

Vibrio aerogenes sp. nov., a facultatively anaerobic marine bacterium that ferments glucose with gas production.

A mesophilic, facultatively anaerobic, marine bacterium, designated strain FG1T, was isolated from a seagrass bed sediment sample collected from Nanwan Bay, Kenting National Park, Taiwan. Cells grown in broth cultures were motile, Gram-negative rods; motility was normally achieved by two sheathed flagella at one pole of the cell. Strain FG1T required Na+ for growth, and exhibited optimal growth at 30-35 degrees C, pH 6-7 and about 4% NaCl. It grew anaerobically by fermenting glucose and other carbohydrates with production of various organic acids, including acetate, lactate, formate, malate, oxaloacetate, propionate, pyruvate and succinate, and the gases CO2 and H2. The strain did not require either vitamins or other organic growth factors for growth. Its DNA G+C content was 45.9 mol%. It contained C12:0 as the most abundant cellular fatty acid. Characterization data, together with the results of a 16S rDNA-based phylogenetic analysis, indicate that strain FG1T represents a new species of the genus Vibrio. Thus, the name Vibrio aerogenes sp. nov. is proposed for this new bacterium. The type strain is FG1T (= ATCC 700797T = CCRC 17041T).

Antibiotic activity of lectins from marine algae against marine vibrios.

Saline and aqueous ethanol extracts of marine algae and the lectins from two red algal species were assayed for their antibiotic activity against marine vibrios. Experimental studies were also carried out on the influence of environmental factors on such activity, using batch cultures. The results indicated that many of the saline extracts of the algal species were active and that the activity was selective against those vibrios assayed. The algal extracts were active against Vibrio pelagius and the fish pathogen V. vulnificus, but inactive against V. neresis. Algal lectins from Eucheuma serra (ESA) and Galaxaura marginata (GMA) strongly inhibited V. vulnificus but were inactive against the other two vibrios. The antibacterial activity of algal extracts was inhibited by pretreatment with various sugars and glycoprotein. Extracts of the two red algae, E. serra and Pterocladia capillacea, in saline and aqueous ethanol, inhibited markedly the growth rate of V. vulnificus at very low concentrations. Culture results indicated that metabolites active against V. vulnificus were invariably produced in P. capillacea over a wide range of temperature, light intensity, and nutritional conditions. Enhanced antibacterial activity occurred when P. capillacea was grown under higher irradiance, severe nutrient stress and moderate temperature (20 degrees C), reflecting the specific antibiotic characteristics of this alga. The strong antibiotic activity of lectins towards fish pathogenic bacteria reveals one of the important roles played by algal lectins, as well as the potential high economic value of those marine algae assayed for aquaculture and for biomedical purposes.