Object. The authors applied the technique of microendoscopic discectomy to posterior decompression procedures for lumbar spinal stenosis. The purpose of this study was to determine the feasibility of using an endoscopic technique to treat lumbar spinal stenosis and to evaluate the clinical and radiographic results of microendoscopic posterior decompression (MEPD). Methods. Microendoscopic posterior decompression, which involves a unilateral endoscopic approach for bilateral decompression, was performed in 47 patients. Clinical and radiographic/neuroimaging results were evaluated during the follow-up period (minimum duration 1 year). The clinical results were compared with those of the conventional laminotomy. Radiographic instability and the degree of surgical invasion of the facet joints were evaluated. In a control a group of 29 patients open laminotomy was performed. The clinical outcome was evaluated in 44 patients. The mean follow-up duration was 22 months. The mean rate of improvement was 72% based on the Japanese Orthopaedic Association score, and good results were obtained in 38 patients. Although the rate of morbidity decreased in the MEPD group, the incidence of complication was slightly higher. Effective decompression was demonstrated in the majority of the patients by using magnetic resonance imaging. Radiographic instability appeared in one patient postoperatively, and based on computerized tomography scanning, a tendency toward invasion of the facet joint on the approach side was noted. Conclusions. Microendoscopic posterior decompression is a minimally invasive procedure and is as useful as other conventional procedures in treating lumbar spinal stenosis; however, a few technical problems remain to be solved.

We investigated the relationship between ruminal pH and bacteria in calves fed calf starter with and without forage during weaning transition. First, 16 Holstein bull calves were obtained from dairy farms and equipped with rumen cannulas by cannulation surgery. Then, calves (73.5 ± 4.2 kg; mean ± SE) were assigned to groups fed calf starter either with forage (HAY, n = 8) or without forage (CON, n = 8), and all calves were weaned at 8 weeks of age. Ruminal pH was measured continuously, and rumen fluid samples were collected at 7, 8, 9, and 11 weeks of age, namely −1, 0, 1, and 3 weeks after weaning, respectively, to assess volatile fatty acid concentrations and bacterial DNA. The 24-h mean ruminal pH was significantly (P < 0.05) different between the two groups. Diurnal changes in the 1-h mean ruminal pH were observed throughout the study in the HAY group; however, they were not observed at 0 and 1 weeks after weaning in the CON group. Moreover, the HAY group had significantly (P < 0.05) higher proportions of acetate and butyrate and lower proportion of propionate, and significantly (P < 0.05) lower ruminal acetate-to-propionate ratios were observed in the CON group. The ruminal bacterial diversity indices decreased after −1 week in both groups and increased at 0 and 1 weeks after weaning in the HAY and CON groups, respectively. From the 454 pyrosequencing analysis, significant differences (P < 0.05) were observed in the relative abundance of several phyla (Bacteroidetes, Actinobacteria, and Tenericutes) and one genus (Prevotella) between the two groups. From quantitative real-time PCR analysis, the HAY group had the higher copy numbers of cellulolytic bacteria (Ruminococcus flavefaciens and Ruminococcus albus) compared with the CON group. This study demonstrated that feeding of dietary forage alleviates subacute ruminal acidosis due to diurnal changes in ruminal pH. Furthermore, changes in ruminal pH affect the ruminal bacterial diversity and relative abundance, and these changes might have influenced the establishment of fermentative ruminal functions during weaning transition.

Object The incidence of postoperative spinal epidural hematoma (SEH) is low, and to the best of the authors’ knowledge, no researchers have evaluated its actual incidence and clinical features. The purpose of this study was to investigate the clinical consequences of SEH after microendoscopic posterior decompression (MEPD) in patients with lumbar spinal stenosis. Methods Data obtained in 30 patients undergoing MEPD for lumbar spinal stenosis were reviewed. At 1 week after surgery, magnetic resonance (MR) imaging documented SEHs in 10 patients (33% [Group 1]) and no evidence of SEHs in 20 patients (67% [Group 2]). The authors compared MR imaging findings, postoperative morbidities, and clinical outcomes between the groups. Three Group 1 patients had symptomatic SEHs. All symptoms were mild without associated neurological deterioration and spontaneously subsided within 3 weeks of surgery. Magnetic resonance imaging demonstrated spontaneous regression of the SEH in all patients at 3 months after surgery. In Group 1 patients, however, the authors observed less expansion of the dural sac after 1 year despite sufficient widening of the osseous spinal canal. Low-back pain within 1 week of surgery was moderate in Group 1 and mild in Group 2. Improvements at the final follow up were greater in Group 2 patients. Conclusions The incidence of postoperative SEHs may be greater than reported. Postoperative SEHs caused poor expansion of the dural sac despite its spontaneous regression. In addition, postoperative SEHs caused a delay in the patient’s recovery and led to a poor clinical improvement. The prevention of postoperative SEHs might be required to prevent not only neurological deterioration but also a delay in the patient’s recovery.

To increase intramuscular fat accumulation, Japanese Black cattle are commonly fed a high-grain diet from 10 to 30 months of age although it can result in the abnormal accumulation of organic acids in the rumen. We explored the effect of long-term high-concentrate diet feeding on ruminal pH and fermentation, and its effect on the rumen bacterial community in Japanese Black beef cattle during a 20-month fattening period. Nine castrated and fistulated Japanese Black beef cattle were housed with free access to food and water throughout the study period (10–30 months of age). The fattening stages included Early, Middle, and Late stages (10–14, 15–22, and 23–30 months of age, respectively). Cattle were fed high-concentrate diets for the experimental cattle during fattening. The body weight of the cattle was 439 ± 7.6, 561 ± 11.6, and 712 ± 18.5 kg (mean ± SE) during the Early, Middle, and Late stages, respectively. Ruminal pH was measured continuously during the final 7 days of each stage, and rumen fluid and blood samples were collected on day 4 (fourth day during the final 7 days of the pH measurements). The 24-h mean ruminal pH during the Late stage was significantly lower than that during the Early stage. Total volatile fatty acid (VFA) during the Late stage was significantly lower than during the Early and Middle stages, but no changes were noted in individual VFA components. The lactic acid concentration during the Late stage was significantly higher than that during the Early and Middle stages. The bacterial richness indices decreased significantly during the Late stage in accordance with the 24-h mean ruminal pH. Among the 35 bacterial operational taxonomic units (OTUs) shared by all samples, the relative abundances of OTU8 (Family Ruminococcaceae) and OTU26 (Genus Butyrivibrio) were positively correlated with the 24-h mean ruminal pH. Total VFA concentration was negatively correlated with OTU167 (Genus Intestinimonas), and lactic acid concentration was correlated positively with OTU167 and OTU238 (Family Lachnospiraceae). These results suggested that long-term high-grain diet feeding gradually lowers ruminal pH and total VFA production during the Late fattening stage. However, the ruminal bacterial community adapted to feeding management and the lower pH during the Late stage by preserving their diversity or altering their richness, composition, and function, to enhance lactic acid production in Japanese Black beef cattle.

Twelve ruminally cannulated Holstein calves (age, 12 ± 3 weeks) were used to identify the effect of a probiotic comprised of Lactobacillus plantarum, Enterococcus faecium and Clostridium butyricum on ruminal components. The calves were adapted to a diet containing a 50% high-concentrate (standard diet) for 1 week, and then, the probiotic was given once daily for 5 days (day 1–5) at 1.5 or 3.0 g/100 kg body weight to groups of four calves each. Four additional calves fed the standard diet without probiotic served as the corresponding control. Ruminal pH was measured continuously throughout the 15-day experimental period. Ruminal fluid was collected via a fistula at a defined time predose and on days 7 and 14 to assess volatile fatty acid (VFA), lactic acid and ammonia-nitrogen concentrations, as well as the bacterial community. The probiotic at either dose improved the reduced 24-hr mean ruminal pH in calves. The circadian patterns of the 1 hr mean ruminal pH were identical between the probiotic doses. In both probiotic groups, ruminal lactic acid concentrations remained significantly lower than that of the control. Probiotic did not affect ruminal VFA concentrations. L. plantarum and C. butyricum were not detected in the rumen of calves given the high-dose probiotic, whereas Enterococcus spp. remained unchanged. These results suggest that calves given a probiotic had stable ruminal pH levels (6.6–6.8), presumably due to the effects of the probiotic on stabilizing rumen-predominant bacteria, which consume greater lactate in the rumen.