Modulation of rumen fermentation and microbial community through increasing dietary cation-anion difference in Chinese Holstein dairy cows under heat stress conditions.

AIMS: The effect of increasing dietary cation-anion difference (DCAD) on rumen fermentation and ruminal microbial community in dairy cows under heat stress (HS) conditions were evaluated. METHODS AND RESULTS: This study was performed as a two-period cross-over design during the summer season, with eight lactating dairy cows randomly distributed to either a control DCAD diet (CON: 33·5 mEq/100 g DM) or high DCAD diet (HDCAD: 50·8 mEq/100 g DM). Throughout the present study, the temperature and humidity index (THI; 80·2 ± 4·29) was generally elevated above the threshold (THI = 72) that is reported to cause HS in lactating dairy cows. Rumen liquid samples were collected on 15 and 21 d during each 21 d-period. The absolute concentration of ruminal total volatile fatty acid (TVFA) in HDCAD treatment was significantly (P < 0·05) higher than those in the control, whilst the ruminal pH, NH3 -N, and VFA molar percentages were unaffected through increasing DCAD. Furthermore, the copy numbers of the cellulolytic bacteria Ruminococcus albus and Ruminococcus flavefaciens in rumen fluid significantly (P < 0·05) rose along with the increment of DCAD. Although the Alpha diversity indexes and the bacterial microbiota structure were unaffected, increasing DCAD significantly (P < 0·05) enriched the phylum Fibrobacteres and genus Fibrobacter in the microflora of rumen fluid, whilst the genera Flexilinea and Dubosiella were the most differentially abundant taxa in the control. CONCLUSIONS: Increasing DCAD under HS conditions resulted in a greater concentration of total VFA without affecting rumen bacteria diversity or structure, although the enrichment of some cellulolytic/hemicellulolytic bacteria was observed. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study provides information on the modulation of rumen fermentation and microbial community through the increment of DCAD in Holstein dairy cows under HS conditions.

The risk to the cutaneous nerve branches in the anterior (Wagner) and snuff-box approaches to the trapezium: a cadaveric study.

We compared the risk with the subcutaneous nerves with the anterior (Wagner) and snuff-box approaches to the trapezium in cadavers. Branches that crossed tattooed incision markings or lay within 1 cm of the markings were identified on six matched pairs of fresh-frozen cadaveric hands. Their distance from the proximal end of the incision was recorded. For anterior incisions, there were 20 vulnerable branches in total, at a mean distance of 22 mm from the proximal end of the incision. A total of 13 lay in the distal half of the incision. For snuff-box incisions, there were 18 vulnerable branches in total, at a mean distance of 11 mm from the proximal end of the incision, with 17 of them lying in the proximal half of the incision. Neither incision is without risk to nerve braches, but our study suggests a lesser risk of subcutaneous nerve damage with the snuff-box approach and highlights the greater risk in the proximal half of this incision.

Clinical evaluation of a yeast recombinant hepatitis B vaccine in healthy hospital staff in Singapore.

A yeast recombinant hepatitis B vaccine (subtype adw), derived from purification of HBsAg particles, expressed in the yeast Saccharomyces cerevisiae which contained the gene for HBsAg, was evaluated in 31 healthy adult hospital staff members in Singapore. Each subject received a 10 mcg dose of vaccine intramuscularly at 0, 1 and 6 months. One month after the first two injections of vaccine the seroconversion rate (defined as greater than or equal to 2.7 mIU/ml) was 90%. Two months after the third injection 100% of participants had anti-HBs levels higher than 2.7 mIU/ml and 97% had titers of anti-HBs greater than 10 mIU/ml. The geometric mean titer (GMT) of anti-HBs levels at 2, 3, 6, 8 and 12 months were 21.9, 38.6, 57.6, 1253.4 and 354.1 mIU/ml, respectively. All clinical complaints were mild and transient. They consisted of mild soreness at the injection site, transient fever and headache. There was no correlation between the presence of antibodies to S. cerevisiae with any allergic manifestations. The vaccine was safe and immunogenic for staff exposed to an infection risk and should now be widely used in the extension of hepatitis B immunization programs.