Eikenella Corrodens Vertebral Osteomyelitis in a Young Patient With Type I Diabetes Mellitus

Vertebral osteomyelitis is an uncommon variant of osteomyelitis. Although Staphylococcus and/or Streptococcus are commonly associated, alternate pathogens have been implicated in vertebral osteomyelitis, especially in endemic areas and/or immunocompromised patients. Here, we present a case of a young African American female with type I diabetes mellitus who presented to us with worsening back pain. The MRI lumbar spine was suggestive of vertebral osteomyelitis involving the right facet joint of the fifth lumbar (L5) and the first spinal (S1) joint and a significant narrowing of the thecal sac at the L4-L5 vertebral level with an anterior epidural abscess. The patient was started on empirical antibiotics, and surgical intervention was performed with L4-L5 laminectomy and extraction of the epidural abscess. Her pus culture showed Eikenella corrodens as a possible cause of vertebral osteomyelitis. She had an uneventful recovery after two weeks of antibiotics (intravenous ceftriaxone) therapy.

Pediatric types I and VI choledochal cysts complicated with acute pancreatitis and spontaneous perforation: A case report and literature review

RATIONALE

Choledochal cysts are a congenital disorder of the common bile duct that can cause progressive biliary obstruction and biliary cirrhosis. They were classified by Todani into five types. Of these, type VI choledochal cysts are rarely reported in the literature.

PATIENT CONCERNS

A 22-month-old girl presented with intermittent epigastralgia for approximately 10 days and fever for three days. Fasting and total parenteral nutrition were administered after admission. However, sudden onset of severe epigastric pain occurred. An abdominal sonogram showed turbid ascites and peritonitis was impressed.

DIAGNOSES

An emergent exploratory laparotomy was performed, and perforation of the posterior wall of types I and VI choledochal cysts was observed.

INTERVENTIONS

Intraoperative cholangiography revealed concomitant types I and VI choledochal cysts with stricture of the distal common bile duct. Definite surgery for resection of the choledochal cysts and gallbladder was performed with Roux-en-Y choledochojejunostomy.

OUTCOMES

The patient had no evidence of ascending cholangitis at three years after the operation.

LESSONS

Type VI choledochal cysts are rarely reported in the literature. To our knowledge, this is the first reported pediatric case of concomitant types I and VI choledochal cysts complicated with acute pancreatitis and spontaneous perforation.

Genome-wide identification and characterization of MADS-box family genes related to organ development and stress resistance in Brassica rapa

BACKGROUND

MADS-box transcription factors (TFs) are important in floral organ specification as well as several other aspects of plant growth and development. Studies on stress resistance-related functions of MADS-box genes are very limited and no such functional studies in Brassica rapa have been reported. To gain insight into this gene family and to elucidate their roles in organ development and stress resistance, we performed genome-wide identification, characterization and expression analysis of MADS-box genes in B. rapa.

RESULTS

Whole-genome survey of B. rapa revealed 167 MADS-box genes, which were categorized into type I (Mα, Mβ and Mγ) and type II (MIKC(c) and MIKC*) based on phylogeny, protein motif structure and exon-intron organization. Expression analysis of 89 MIKC(c) and 11 MIKC* genes was then carried out. In addition to those with floral and vegetative tissue expression, we identified MADS-box genes with constitutive expression patterns at different stages of flower development. More importantly, from a low temperature-treated whole-genome microarray data set, 19 BrMADS genes were found to show variable transcript abundance in two contrasting inbred lines of B. rapa. Among these, 13 BrMADS genes were further validated and their differential expression was monitored in response to cold stress in the same two lines via qPCR expression analysis. Additionally, the set of 19 BrMADS genes was analyzed under drought and salt stress, and 8 and 6 genes were found to be induced by drought and salt, respectively.

CONCLUSION

The extensive annotation and transcriptome profiling reported in this study will be useful for understanding the involvement of MADS-box genes in stress resistance in addition to their growth and developmental functions, which ultimately provides the basis for functional characterization and exploitation of the candidate genes for genetic engineering of B. rapa.

Purification, crystallization and preliminary X-ray characterization of the Acetivibrio cellulolyticus type I cohesin ScaC in complex with the ScaB dockerin

The cellulosome, a highly elaborate extracellular multi-enzyme complex of cellulases and hemicellulases, is responsible for the efficient degradation of plant cell-wall carbohydrates by anaerobic microorganisms. Cohesin and dockerin recognition pairs are integral to the architecture of the cellulosome. Thus, type I cohesin:dockerins are important for attaching the modular enzymatic components to primary scaffoldins to form the cellulosome. In contrast, type II dockerins located in primary scaffoldins bind to anchoring scaffoldins, thus contributing to the cell-surface attachment of the entire complex. Since anchoring scaffoldins usually contain more than one type II cohesin, they contribute to the assembly of polycellulosomes. Acetivibrio cellulolyticus possesses an extremely complex cellulosome arrangement which is organized by a primary enzyme-binding scaffoldin (ScaA), two anchoring scaffoldins (ScaC and ScaD) and an unusual adaptor scaffoldin (ScaB). A ScaB dockerin mutated to inactivate one of the two putative cohesin-binding interfaces complexed with the ScaC cohesin from A. cellulolyticus has been purified and crystallized and data were collected from tetragonal and monoclinic crystal forms to resolutions of 1.5 and 6.0 Å, respectively.

Roles of hydrophilicities and hydrophobicities of dye and sacrificial electron donor on the photochemical pathway

Relative rates of the photosensitized production of singlet oxygen ((1)O(2)) and of superoxide (O(2) (•-)) were determined using different couples of dyes and sacrificial electron donors (SEDs) of either high or low hydrophobicities. Such rates were also measured in the absence and presence of single unilamellar vesicles (SUVs) with 9DMPC:1DMPA mol ratio composition. The dyes aluminum phthalocyanine tetrasulfonate (AlPcS(4)) and pheophorbide-a (PHEO) were used as hydrophilic and hydrophobic photosensitizers, respectively. Xanthine (X) and glutathione (GSH) were used as hydrophobic and hydrophilic SEDs, respectively. The presence of SUVs in the aqueous sample produces the physical separation or encounter of SEDs and photosensitizers according to their membrane binding constants. When both the SED and the photosensitizer are localized within the same phase, a strong decrease in the rate of (1)O(2) formation, united to a strong increase in the rate of O(2) (•-) formation, is observed, relative to when both of these species are localized in different phases. The lipid phase is always present in the biological milieu. Thus, the use of a hydrophobic couple of both dye and SED (as in the case of X and PHEO), as well as a hydrophilic couple of both dye and SED (as in the case of GSH and AlPcS4), should strongly favor the Type I mechanism over the Type II. Since only a small number of hydroxyl radicals are needed to initiate a chain reaction of phospholipid peroxidation, the latter could be more toxic to the tumor tissue than peroxidation by a much higher concentration of singlet oxygen molecules.

MPZP: a novel small molecule corticotropin-releasing factor type 1 receptor (CRF1) antagonist

The extrahypothalamic stress peptide corticotropin-releasing factor (CRF) system is an important regulator of behavioral responses to stress. Dysregulation of CRF and the CRF type 1 receptor (CRF(1)) system is hypothesized to underlie many stress-related disorders. Modulation of the CRF(1) system by non-peptide antagonists currently is being explored as a therapeutic approach for anxiety disorders and alcohol dependence. Here, we describe a new, less hydrophilic (cLogP approximately 2.95), small molecule, non-peptide CRF(1) antagonist with high affinity (K(i)=4.9 nM) and specificity for CRF(1) receptors: N,N-bis(2-methoxyethyl)-3-(4-methoxy-2-methylphenyl)-2,5-dimethyl-pyrazolo[1,5-a] pyrimidin-7-amine (MPZP). The compound was systemically administered to adult male rats in two behavioral models dependent on the CRF(1) system: defensive burying (0, 5, 20 mg/kg, n=6-11 for each dose) and alcohol dependence (0, 5, 10, 20 mg/kg, n=8 for each self-administration group). Acute administration of MPZP reduced burying behavior in the defensive burying model of active anxiety-like behavior. MPZP also attenuated withdrawal-induced excessive drinking in the self-administration model of alcohol dependence without affecting nondependent alcohol drinking or water consumption. The present findings support the proposed significance of the CRF(1) system in anxiety and alcohol dependence and introduce a promising new compound for further development in the treatment of alcohol dependence and stress-related disorders.

Auditory neurons make stereotyped wiring decisions before maturation of their targets

Cochlear ganglion neurons communicate sound information from cochlear hair cells to auditory brainstem neurons through precisely wired circuits. Understanding auditory circuit assembly is a significant challenge because of the small size of the otic vesicle and difficulties labeling and imaging embryonic neurons. We used genetic fate mapping in the mouse to visualize the morphologies of individual cochlear ganglion neurons throughout development, from their origin in the Neurogenin1-positive neurogenic domain in the otic vesicle to the formation of connections with targets in the cochlea and in the cochlear nucleus. We found that auditory neurons with different patterns of connectivity arise from discrete populations of Neurogenin1-positive precursors that make stereotyped wiring decisions depending on when and where they are born. Auditory precursors are segregated from vestibular precursors early in neurogenesis. Within this population, cochlear ganglion neurons with type I and type II morphologies are apparent before birth and develop within common pools of precursors. The peripheral projections are initially complex and branched and then become simple and straight after reaching the edge of the sensory epithelium. Subsequently, a small number of projections attain obvious type II morphologies, beginning at embryonic day 16.5 (E16.5), when hair cells begin to differentiate. Centrally, cochlear ganglion axons are topographically organized in the auditory brainstem as early as E15.5, when the cochlear nucleus is still immature. These findings suggest that Neurogenin1 precursors possess intrinsic programs of differentiation that direct early auditory circuit assembly events before the maturation of presynaptic and postsynaptic target cells.

Comparative histochemical composition of muscle fibres in a pre- and a postvertebral muscle of the cervical spine

References to histochemistry are extensive for human limb muscles but occur less frequently in relation to vertebral muscle. Most vertebral muscle literature has been concerned with muscle fibre characteristics in the lumbar and thoracic spine, due in large part to the incidence of low back pain and idiopathic scoliosis. However few studies have investigated the histochemical composition of neck muscles in humans: and, to our knowledge, no previous study has examined the antagonistic longus colli and multifidus muscle pair. In addition, while age-related segmental degeneration is most prominent between C5 and C7, it is not known whether these osteoligamentous changes are paralleled by changes in muscle fibre ratio. Tissue blocks comprising muscle and bone from C5-C7 segments were harvested at autopsy from 16 subjects with ages ranging from 4 to 77 years. The prevertebral longus colli and postvertebral multifidus muscle pairs were randomly selected from one or other side in each subject. The tissue was frozen, sectioned and histochemically stained for myofibrillar adenosine triphosphatase. Analysis of muscle fibre types was performed by light microscopy. Wilcoxon paired t-tests were used to ascertain whether intramuscular and intermuscular differences in fibre composition were significant. In addition, correlation and regression analyses were used to determine whether fibre type proportions changed in either muscle with increasing age. The present study has revealed histochemical differences between longus colli and multifidus at the level of the C5-C7 vertebral segments. Multifidus comprises a significantly greater proportion of type I than type II fibres. Longus colli comprises a significantly greater proportion of type II fibres than multifidus. Further there were no changes in fibre type proportion in either muscle with increasing age. These observations suggest that longus colli responds equally to postural and phasic demands, whereas multifidus is predominantly postural. Also it would appear that age-related structural alterations in lower cervical segments are not paralleled by changes in muscle fibre ratio.