Evaluation of transferability of R-plasmid in bacteriocin-producing donors to bacteriocin-resistant recipients

Bacteriocin-producing Escherichia coli (donors) rapidly kill conventional recipient E. coli DH5α in conjugation experiments. To evaluate plasmid transferability of bacteriocin-producing donors, we established 2 different bacteriocin-resistant mutants derived from E. coli DH5α and used them as recipients. When the bacteriocin-resistant mutants were used in conjugation experiments, the transconjugant recovery from 20 bacteriocin-producing donors increased from 5% (1/20) to 65% (13/20), and the transfer frequencies increased. These results showed that bacteriocins inhibited the transfer of the R-plasmid from bacteriocin-producing donors. Thus, application of bacteriocin-resistant recipients might aid the evaluation of the potential transferability of plasmids from bacteriocin-producing donors.     

Emergency EC-IC bypass for symptomatic atherosclerotic ischemic stroke

Previous studies have shown that extracranial–intracranial (EC-IC) bypass surgery has no preventive effect on subsequent ipsilateral ischemic stroke in patients with symptomatic atherosclerotic internal carotid occlusion and hemodynamic cerebral ischemia. A few studies have assessed whether an urgent EC-IC bypass surgery is an effective treatment for main trunk stenosis or occlusion in acute stage. The authors retrospectively reviewed 58 consecutive patients who underwent urgent EC-IC bypass for symptomatic internal carotid artery or the middle cerebral artery stenosis or occlusion between January 2003 and December 2011. Clinical characteristics and neuroimagings were evaluated and analyzed. Based on preoperative angiogram, responsible lesions were the internal carotid artery in 19 (32.8 %) patients and the middle cerebral artery in 39 (67.2 %). No hemorrhagic complication occurred. Sixty-nine percent of patients showed improvement of neurological function after surgery, and 74.1 % of patients had favorable outcome. Unfavorable outcome was associated with insufficient collateral flow and new infarction after bypass surgery.     

Distribution of periodontopathic bacterial species in dogs and their owners

ObjectivePresently, a large number of individuals consider their companion animals as family members and have close contact with them in daily life. The purpose of the present study was to analyze the distribution of periodontopathic bacterial species in oral specimens taken from dogs and their owners.DesignDental plaque specimens were collected from 66 dogs and 81 members of 64 families who came to an animal clinic or dog training school in Okayama, Japan, in 2011. Bacterial DNA was extracted from each specimen and PCR analyses using primers specific for 11 periodontopathic species, Porphyromonas gingivalis, Porphyromonas gulae, Treponema denticola, Tannerella forsythia, Capnocytophaga ochracea, Capnocytophaga sputigena, Prevotella intermedia, Prevotella nigrescens, Aggregatibacter actinomycetemcomitans, Campylobacter rectus, and Eikenella corrodens were performed.ResultsP. gulae (71.2%), T. forsythia (77.3%), and C. rectus (66.7%) were frequently found in the dogs, whereas the detection rates of those species in humans were less frequent at 16.0%, 30.9%, and 21.0%, respectively. P. gulae was identified in 13 human subjects and each of their dogs was also positive for the species. Furthermore, E. corrodens and T. denticola in specimens obtained from dogs were correlated with their presence in specimens from owners who had close contact with them.ConclusionsThese results suggest that several periodontopathic species could be transmitted between humans and their companion dogs, though the distribution of periodontopathic species in both is generally different.     

Capillary filling analysis by digital subtraction angiography for vertebro-basilar insufficiency

Abstract

Vertebro-basilar insufficiency (VBI) is a vague clinical entity including several symptoms such as faintnessdizziness, vertigo. Millikan and Siekert reported a ‘syndrome of intermittent insufficiency of basilar arterial system'1. But vascular abnormalities responsible for such symptoms are often hardly diagnosed by conventional angiography, because vertebro-basilar artery systems have many kinds of anomalous congenital origins2. Conventional angiography gives us arterial informations such as stenosis, occlusion and malformationsbut it often fails to reveal capillary perfusions because of its relatively poor density resolution. Digital subtraction angiography (DSA) is considered to have improved density resolutioni, and it may enable us to detect vascular perfusions more sensitively in the capillary phase. In this study, we evaluated the usefulness of the capillary filling analysis in digital subtraction angiography for diagnosis of VBI.     

Up-regulation of c-myc gene expression following focal ischemia in the rat brain

Abstract

Changes in gene expression including that ofc-fos occur following cerebral ischemia. Proto-oncogenes c- myc and s-myc and oncosuppressor gene p53 are known to induce apoptosis in some types of cells, whereas proto-oncogene bcl-2 inhibits apoptosis. Possible induction of mRNAs for c-myc, N-myc, s-myc, c-fos, p53 and bcl-2 was examined following focal ischemia in the rat anterior cortex, hippocampus, thalamus and cerebellum by Northern blot analysis. Animals were decapitated 1, 2, 6, 12, and 24 hours following the left middle cerebral artery (MCA) occlusion. In sham-operated control rats, the mRNAs for c- myc, N-myc, c-fos and p53 were present in the anterior cortex, hippocampus; thalamus on both sides, and in the cerebellum, whereas those for s-myc and bcl-2 were not The c-myc gene expression was rapidly and markedly induced by the MCA occlusion in the ipsilateral anterior cortex, hippocampus and thalamus in a time-dependent manner. In these regions, the c-fos gene expression was also induced as early as 1 hour after the MCA occlusion. The p-53 mRNA was induced in the ipsilateral hippocampus at 24 hours after MCA occlusion. In contrast, mRNAs for N-myc, s-myc and bcl-2 were not induced following MCA occlusion. These results indicate a possibility that high-level expression of the c-myc gene may be involved in the ischemic cellular events including apoptosis. [Neurol Res 1996; 18: 559-563]     

PKCbeta regulates ischemia/reperfusion injury in the lung

Activation of PKCbetaII is associated with the response to ischemia/reperfusion (I/R), though its role, either pathogenic or protective, has not been determined. In a murine model of single-lung I/R, evidence linking PKCbeta to maladaptive responses is shown in the following studies. Homozygous PKCbeta-null mice and WT mice fed the PKCbeta inhibitor ruboxistaurin subjected to I/R displayed increased survival compared with controls. In PKCbeta-null mice, phosphorylation of extracellular signal-regulated protein kinase-1 and -2 (ERK1/2), JNK, and p38 MAPK was suppressed in I/R. Expression of the immediate early gene, early growth response-1 (Egr-1), and its downstream target genes was significantly increased in WT mice in I/R, particularly in mononuclear phagocytes (MPs), whereas this expression was attenuated in PKCbeta-null mice or WT mice fed ruboxistaurin. In vitro, hypoxia/reoxygenation-mediated induction of Egr-1 in MPs was suppressed by inhibition of PKCbeta, ERK1/2, and JNK, but not by inhibition of p38 MAPK. These findings elucidate key roles for PKCbetaII activation in I/R by coordinated activation of MAPKs (ERK1/2, JNK) and Egr-1.     

Study on the Segmentation of the Right Posterior Sector of the Liver

World Journal of Surgery - The border between segments VI and VII of the right posterior sector of the liver is controversial owing to lack of anatomical landmarks. This study aimed to examine the...