Role of the terminator hairpin in the biogenesis of functional Hfq-binding sRNAs.

Rho-independent transcription terminators of the genes encoding bacterial Hfq-binding sRNAs possess a set of seven or more T residues at the 3' end, as noted in previous studies. Here, we have studied the role of the terminator hairpin in the biogenesis of sRNAs focusing on SgrS and RyhB in Escherichia coli. We constructed variant sRNA genes in which the GC-rich inverted repeat sequences are extended to stabilize the terminator hairpins. We demonstrate that the extension of the hairpin stem leads to generation of heterogeneous transcripts in which the poly(U) tail is shortened. The transcripts with shortened poly(U) tails no longer bind to Hfq and lose the ability to repress the target mRNAs. The shortened transcripts are generated in an in vitro transcription system with purified RNA polymerase, indicating that the generation of shortened transcripts is caused by premature transcription termination. We conclude that the terminator structure of sRNA genes is optimized to generate functional sRNAs. Thus, the Rho-independent terminators of sRNA genes possess two common features: a long T residue stretch that is a prerequisite for generation of functional sRNAs and a moderate strength of hairpin structure that ensures the termination at the seventh or longer position within the consecutive T stretch. The modulation of the termination position at the Rho-independent terminators is critical for biosynthesis of functional sRNAs.

Analgesic Effect of Double-Level Retrolaminar Paravertebral Block for Breast Cancer Surgery in the Early Postoperative Period: A Placebo-Controlled, Randomized Clinical Trial.

Thoracic epidural anesthesia (TEA) and paravertebral block (PVB) have been performed for perioperative regional anesthesia in the trunk. However, TEA and PVB are associated with a risk of serious complications, such as pneumothorax, hypotension, or nerve damage. Retrolaminar paravertebral block (RLB) was introduced as a new alternative to PVB. This new approach might lower the risk of serious complications, but its use has not been well established yet. Therefore, we conducted a double-masked, placebo-controlled, randomized clinical trial to evaluate the efficacy of a double-level RLB for postoperative analgesia after breast cancer surgery. A total of 122 women who underwent breast cancer surgery with axillary lymph node dissection under general anesthesia were allocated into RLB group (60 patients) and Control group (62 patients). RLB was performed upon surgery completion with 15 ml ropivacaine (0.5%) for each lamina of the T2 and T4 vertebrae. In Control group, the same volume of normal saline was injected at each level. The time to first postoperative analgesic administration was significantly longer in RLB group than that in Control group (161.5 min vs. 64.0 min). The pain score in RLB group was significantly lower immediately after surgery. However, the number of patients requiring analgesics during the 12-hour post-surgical period was similar between RLB group (20 patients) and Control group (22 patients). In conclusion, the double-level RLB could delay the time to initial administration of analgesics, but this technique may be insufficient to reduce the analgesic requirement within the 12-hour postoperative period following breast cancer surgery.

[Perioperative management of lung transplantations in patients with pulmonary arterial hypertension compared with that in patients with lymphangiomyomatosis].

BACKGROUND: The number of lung transplantation has tended to increase as a treatment for patients with pulmonary arterial hypertension (PAH) and lymphangiomyomatosis (LAM) in Japan. However, we have little evidence about the comparison of perioperative management in patients with PAH and that in patients with LAM. METHODS: In this retrospective study, ten patients with PAH and seventeen patients with LAM who underwent the lung transplantations between 2006 and 2011 were enrolled. RESULTS: PAH patients received double lung transplantation with intraoperative cardiopulmonary bypass (CPB) support. Before anesthesia induction, percutaneous cardiopulmonary support (PCPS) was begun. Most of LAM patients received single lung transplantation without using CPB support and PCPS support before anesthesia induction. But sometimes during an operation PCPS support was necessary. Postoperative PCPS support showed no significant differences between PAH and LAM. The four year survival rate was 80% (PAH) and 87.8% (LAM). Pao2/FIo2 in patients with PAH and in those with LAM, %FEV10 in those with LAM after surgery improved when compared to those before surgery. CONCLUSIONS: The large difference in perioperative management between patients with PAH and those with LAM is an important knowledge for anesthesist.

[Assessment of the perioperative factors contributing to the hemodynamic changes during surgery in ten patients with pheochromocytoma].

BACKGROUND: Intensive perioperative management is required for adrenalectomy in patients with pheocromocytoma because of the unstable hemodynamics and life threatening cardiovascular disturbances due to catecholamine surge from the neuroendocrine tumors. The aim of this study was to assess the perioperative factors contributing to the hemodynamic changes during surgery in pheochromocytoma. METHODS: Ten patients with pheochromocytoma undergoing elective adrenalectomy were enrolled in this retrospective study. The circulating blood volume before surgery and the perioperative factors associated with hemodynamic changes during surgery were assessd by the pulse dye densitometry and VigileoTM/ FroTracTM system, respectively. RESULTS: The decreases of blood pressure after resections of the central veins from tumors were significantly greater in laparotomy than those in laparoscopic surgery (P<0.05). In addition, the decreases of blood pressure after resection of the central were correlated with tumor sizes (R= -0.611), perioperative noradrenaline (NA) blood levels (R= -0.860), perioperative amounts of NA in urine (R= -0.743), and mean stroke volume variations for 5 min after resection of the veins(R= - 0.679). CONCLUSIONS: The decreases of blood pressure after resections of the central veins are dependent on the perioperative blood NA levels, the level of NA in the perioperative urine testig, and tumor sizes.

Critical role of gut microbiota in the production of biologically active, free catecholamines in the gut lumen of mice.

There is increasing interest in the bidirectional communication between the mammalian host and prokaryotic cells. Catecholamines (CA), candidate molecules for such communication, are presumed to play an important role in the gut lumen; however, available evidence is limited because of the lack of actual data about luminal CA. This study evaluated luminal CA levels in the gastrointestinal tract and elucidated the involvement of gut microbiota in the generation of luminal CA by comparing the findings among specific pathogen-free mice (SPF-M), germ-free mice (GF-M), and gnotobiotic mice. Substantial levels of free dopamine and norepinephrine were identified in the gut lumen of SPF-M. The free CA levels in the gut lumen were lower in GF-M than in SPF-M. The majority of CA was a biologically active, free form in SPF-M, whereas it was a biologically inactive, conjugated form in GF-M. The association of GF-M with either Clostridium species or SPF fecal flora, both of which have abundant ß-glucuronidase activity, resulted in the drastic elevation of free CA. The inoculation of E. coli strain into GF-M induced a substantial amount of free CA, but the inoculation of its mutant strain deficient in the ß-glucuronidase gene did not. The intraluminal administration of DA increased colonic water absorption in an in vivo ligated loop model of SPF-M, thus suggesting that luminal DA plays a role as a proabsorptive modulator of water transport in the colon. These results indicate that gut microbiota play a critical role in the generation of free CA in the gut lumen.

The effect of probiotics on gastric mucosal permeability in humans administered with aspirin.

OBJECTIVE: To examine whether a probiotic strain, Lactobacillus gasseri OLL2716 (LG21), can protect the gastric mucosal integrity from aspirin using urinary sucrose excretion (USE) test. MATERIALS AND METHODS: In the study using high-dose aspirin, the USE tests were carried out in 29 volunteers before and after LG21 treatment for 4 weeks. In the study using patients undergoing low-dose aspirin therapy, USE tests were performed in 37 subjects who took LG21 for 16 weeks. Stool occult blood was examined by the guaiac method. RESULTS: In the former study, the elevation in the USE value after aspirin loading significantly decreased after LG21 treatment (Median ± SD; 0.244 ± 0.237 vs. 0.208 ± 0.112%, p = 0.018). In the latter study, the USE value significantly decreased in the period with LG21 treatment (p = 0.033), while no significant difference was found in the period without LG21 (p = 0.113). The number of positive occult blood tests decreased during LG21 treatment. CONCLUSIONS: The regular ingestion of LG21 may protect the integrity of the gastric mucosal permeability against aspirin.

Effect of gut microbiota early in life on aggressive behavior in mice.

Recent reports have indicated that gut microbiota modulates the responses to stress through the microbiota-gut-brain axis in mice, suggesting a connection between gut microbiota and brain function. We hypothesized that the gut microbiota early in life would have an effect on aggressiveness, and examined how gut microbiota affect aggressive behaviors in mice. BALB/c mice were housed in germ-free (GF) and ex-germ-free (Ex-GF) isolators. An aggression test was performed between castrated and a non-castrated mice at 8 weeks of age; the mice were allowed to confront each other for 10 min in strictly contamination-free environments. To evaluate aggressive behavior related to gut microbiota, we orally administered diluted Ex-GF mouse feces to the offspring of GF mice at 0, 6, and 10 weeks. GF mice showed more aggression than Ex-GF mice. Furthermore, GF mice who were administered feces of the Ex-GF group at 0-week-old were less aggressive than the GF mice. These findings suggested that the gut microbiota in the early stages of development was likely to have an effect on aggressiveness. Maintenance of healthy gut microbiota early in life can affect the mitigation of aggressive behavioral characteristics throughout the lifetime.