An important alternative to free tissue transfer in patients requiring correction of soft tissue chin defects are local and regional flaps, such as the pectoralis major myocutaneous flap and deltopectoral flap. With predictable vascular supply, potential for large size, and good aesthetic match for facial and cervical skin, the deltopectoral flap can offer the reconstructive surgeon additional options in patients who lack vessels suitable for free tissue transfer. The use of an expanded deltopectoral flap for a staged reconstruction of the chin in a patient with cancer recurrences, concomitant resections, radiation and multiple reconstructions is reported.
Chin reconstruction; Deltopectoral
Giant fibrolipomas involving the upper extremities are rare tumours. These large masses grow slowly and produce symptoms due to their size, location and compression of adjacent structures. Surgical excision usually leads to complete recovery from symptoms.
Intraneural lipomas of the ulnar nerve or its branches are rare benign tumours. Although most intraneural lipomas present as asymptomatic tumours, some may present as compression neuropathies due to their location. In the majority of cases these tumours can be enucleated without damage to the nerve fibres.
Intraneural lipoma; Ulnar nerve
Acute median nerve compression usually occurs from increased pressure within the carpal tunnel and forearm compartments. Although the hyperesthesia from burns may mimic symptoms of acute compression neuropathy, clinical diagnosis should be made from history, clinical signs and symptoms. Early recognition and decompression of the carpal tunnel either as part of the burn excision or along with escharotomy usually leads to full recovery.
Burns of hands and wrist; Median nerve compression neuropathy
The superficial branch of the radial nerve is highly vulnerable to trauma, irritation and compression due to its anatomical location. Intraneural lipomas and fibrolipomas arising from the supporting tissues of this peripheral nerve can cause compression of the adjacent nerve leading to symptoms of neuritis of the radial nerve or Wartenberg syndrome.
Intraneural lipoma; Wartenberg syndrome
Background & Objectives:
Bifidobacteria colonize the gut after the first week of life and remain an important component of the gut microbiota in infancy. This study was carried out to characterize the diversity and number of bifidobacteria colonizing the gut in Indian neonates and to investigate whether asymptomatic infection with rotavirus in the first month of life affected gut colonization by bidifobacteria.
DNA was isolated from faeces of 14 term-born neonates who were under surveillance for rotavirus infection. Bacterial and bifidobacterial diversity was evaluated by temporal temperature gradient electrophoresis (TTGE) of 16S rDNA amplified using total bacteria and bifidobacteria-specific primers. Real time PCR, targeting 16S rDNA, was used to quantitate faecal bifidobacteria and enterobacteria.
TTGE of conserved bacterial 16S rDNA showed 3 dominant bands of which Escherichia coli (family Enterobacteriaceae) and Bifidobacterium (family Bifidobacteriaceae) were constant. TTGE of Bifidobacterium genus-specific DNA showed a single band in all neonates identified by sequencing as Bifidobacterium longum subsp. infantis. Faecal bifidobacterial counts (log10 cfu/g faeces) ranged from 6.1 to 9.3 and enterobacterial counts from 6.3 to 9.5. Neonates without and with rotavirus infection in the first week of life did not show significant differences in the median count of bifidobacteria (log10 count 7.48 vs. 7.41) or enterobacteria (log10 count 8.79 vs. 7.92).
Interpretation & Conclusions:
B. longum subsp. infantis was the sole bifidobacterial species colonizing the gut of Indian neonates. Asymptomatic rotavirus infection in the first month of life was not associated with alteration in faecal bifidobacteria or enterobacteria.
Bifidobacterium; colonization; gut; neonates; rotavirus
Fractures of the pelvis associated with uncontrollable hypotension are managed by stabilization of fractures and arteriographic embolization of the bleeding vessels. Embolization of these arteries may result in necrosis of the buttocks. The use of a transverse lumbar artery-based flap can be used for repair of these defects.
Transverse lumbar flap
Soft tissue defects of the great toe that include exposed tendon and bone present a reconstructive challenge for plastic surgeons. A distally based dorsalis pedis island flap based on the first dorsal metatarsal artery, which has been successfully used to cover the soft tissue defect following wide excision of melanoma of the big toe, is reported
Dorsal metatarsal artery flap
Acute carpal tunnel syndrome is the most common compression neuropathy of the upper extremity following trauma. A rare occurence of spontaneous bleeding into the carpal tunnel, presenting as acute carpal tunnel syndrome, is presented.
Carpal tunnel syndrome; Spontaneous bleeding
Tumor cells have an altered metabolic phenotype characterized by increased glycolysis and diminished oxidative phosphorylation. Despite the suspected importance of glycolysis in tumorigenesis, the temporal relationship between oncogene signaling, in vivo tumor formation and glycolytic pathway activity is poorly understood. Moreover, how glycolytic pathways are altered as tumors regress remains unknown. Here we use a switchable model of MYC-driven liver cancer, along with hyperpolarized 13C-pyruvate magnetic resonance spectroscopic imaging (MRSI) to visualize glycolysis in de novo tumor formation and regression. LDHA abundance and activity in tumors is tightly correlated to in vivo pyruvate conversion to lactate and is rapidly inhibited as tumors begin to regress, as are numerous glycolysis pathway genes. Conversion of pyruvate to alanine predominates in pre-cancerous tissues prior to observable morphologic or histological changes. These results demonstrate that metabolic changes precede tumor formation and regression and are directly linked to the activity of a single oncogene.
First discovered as a structure-specific endonuclease that evolved to cut at the base of single-stranded flaps, flap endonuclease (FEN1) is now recognized as a central component of cellular DNA metabolism. Substrate specificity allows FEN1 to process intermediates of Okazaki fragment maturation, long-patch base excision repair, telomere maintenance, and stalled replication fork rescue. For Okazaki fragments, the RNA primer is displaced into a 5′ flap and then cleaved off. FEN1 binds to the flap base and then threads the 5′ end of the flap through its helical arch and active site to create a configuration for cleavage. The threading requirement prevents this active nuclease from cutting the single-stranded template between Okazaki fragments. FEN1 efficiency and specificity are critical to the maintenance of genome fidelity. Overall, recent advances in our knowledge of FEN1 suggest that it was an ancient protein that has been fine-tuned over eons to coordinate many essential DNA transactions.
endonucleases; genome fidelity; genome stability; long-patch base excision repair; Okazaki fragment maturation
viral epigenetics; SV40; transcription; replication origin; H3K9; H3K4
We report a high frequency of drug resistance mutations among patients with unusual insertions or deletions at the β3–β4 hairpin-loop-coding region of HIV-1 subtype C reverse transcriptase, during failure of first-line antiretroviral therapy containing only reverse transcriptase inhibitors in Chennai, India.
The derivation of stably cultured cell lines has been critical to the advance of molecular biology. We profiled gene expression in the first two generally available cell lines derived from zebra finch. Using Illumina RNA-seq, we generated ~93 million reads and mapped the majority to the recently assembled zebra finch genome. Expression of most Ensembl-annotated genes was detected, but over half of the mapped reads aligned outside annotated genes. The male-derived G266 line expressed Z-linked genes at a higher level than did the female-derived ZFTMA line, indicating persistence in culture of the distinctive lack of avian sex chromosome dosage compensation. Although these cell lines were not derived from neural tissue, many neurobiologically relevant genes were expressed, although typically at lower levels than in a reference sample from auditory forebrain. These cell lines recapitulate fundamental songbird biology and will be useful for future studies of songbird gene regulation and function.
zebra finch; RNA-seq; song learning; gene expression; Illumina; dosage compensation; bird; sex chromosome
The platelet adenosine diphosphate (ADP)-receptor blocker clopidogrel is effective in reducing the rate of thrombosis in cardiovascular disease, but may also have nonplatelet activity. However, there is variability in the suppression of platelet function in individuals, leading to the concept of clopidogrel resistance, that is, reduced platelet-suppressing activity. We tested the hypothesis that some of the beneficial effect of clopidogrel may be due to the variable activity of this drug on the vascular system (assessed by plasma markers von Willebrand factor and soluble E-selectin, and functional arterial pulse wave velocity) and inflammation (C-reactive protein and interleukin-6) while 32 patients with coronary artery disease taking 75 mg clopidogrel daily, and again 2 weeks after cessation of clopidogrel therapy. Platelet responsiveness to clopidogrel was assessed by the phosphorylation of intracellular regulatory protein—vasodilator-stimulated phosphoprotein method and aggregometry to ADP. Response to aspirin was assessed using arachidonic acid (AA), and soluble P-selectin and PAC-1 were also measured. While on clopidogrel, there were no relationships between any vascular or inflammatory index and the response to clopidogrel. After stopping clopidogrel, there were no differences in platelet aggregation to AA, or the expression of P-selectin or PAC-1 at rest, or after stimulation by AA, but platelet responses to ADP all increased (p < 0.01). Although soluble P-selectin increased when clopidogrel was stopped (p = 0.006), there were no changes in plasma markers or vascular function. We conclude that 75 mg/day clopidogrel has no effect of markers of vascular function or inflammation.
clopidogrel; platelet aggregation; vascular function; inflammation; coronary artery disease; platelet aggregation
Microbial diversity of 1,000 m deep pelagic sediment from off Coast of Andaman Sea was analyzed by a culture independent technique, bacterial tag encoded FLX titanium amplicon pyrosequencing. The hypervariable region of small subunit ribosomal rRNA gene covering V6–V9, was amplified from the metagenomic DNA and sequenced. We obtained 19,271 reads, of which 18,206 high quality sequences were subjected to diversity analysis. A total of 305 operational taxonomic units (OTUs) were obtained corresponding to the members of firmicutes, proteobacteria, plantomycetes, actinobacteria, chloroflexi, bacteroidetes, and verucomicrobium. Firmicutes was the predominant phylum, which was largely represented with the family bacillaceae. More than 44 % of sequence reads could not be classified up to the species level and more than 14 % of the reads could not be assigned to any genus. Thus, the data indicates the possibility for the presence of uncultivable or unidentified novel bacterial species. In addition, the community structure identified in this study significantly differs with other reports from marine sediments.
Metagenomics; 16S rRNA; Pyrosequencing; Microbial richness; Andaman Sea
One of the most rapidly growing areas of dentistry from the stand point of both interest and need is maxillofacial prosthetics. The research of cancer has made understanding and treatment of this dreadful disease a possibility. Still the rehabilitation of these patients is a daunting job. The factors which determine the prognosis of prosthetic reconstruction are size of the defect, ability of the hard and soft tissues in defect area, proximity of vital structures, systemic conditions and the most important of all, patients attitude and temperament. This article presents case of a hemimaxillectomy patient, where rehabilitation is carried out with a simple hollow bulb obturator, which is light in weight and aids in better retention and comfort of the patient.
How to cite this article: Manikanatan NS, Balakrishnan D. Hollowbulb Obturator with Cast Retainers: A Case Report. J Int Oral Health 2013; 5(5):116-9.
cast retainers; hemimaxillectomy; hollow bulb obturator prosthesis; prosthetic rehabilitation
We investigate the electronic structure of a complex conventional superconductor, ZrB12 employing high resolution photoemission spectroscopy and ab initio band structure calculations. The experimental valence band spectra could be described reasonably well within the local density approximation. Energy bands close to the Fermi level possess t2g symmetry and the Fermi level is found to be in the proximity of quantum fluctuation regime. The spectral lineshape in the high resolution spectra is complex exhibiting signature of a deviation from Fermi liquid behavior. A dip at the Fermi level emerges above the superconducting transition temperature that gradually grows with the decrease in temperature. The spectral simulation of the dip and spectral lineshape based on a phenomenological self energy suggests finite electron pair lifetime and a pseudogap above the superconducting transition temperature.
Injury to the central nervous system is characterized by the localization of activated microglia at the site of injury. The peripheral benzodiazepine receptor (PBR) expressed on the outer mitochondrial membrane of the activated microglia is a sensitive biomarker for the detection of this neuroinflammatory response to an insult. PK11195, an isoquinoline ligand that specifically binds PBR, when tagged with a positron emitter can be used as a tracer for molecular imaging of this receptor in vivo by positron emission tomography. [11C](R)PK11195 has been used in the imaging of various neuroinflammatory disorders such as Alzheimer’s’ and multiple sclerosis. Based on our small animal PET imaging studies using a neonatal rabbit model of maternal inflammation induced cerebral palsy, we propose that PET imaging using [11C](R)PK11195 may be a valuable tool for detecting neuroinflammation in the brain of newborns born to mothers with chorioamnionitis.
Cytochrome c unfolds locally and reversibly upon heating at pH 3. UV resonance Raman (UVRR) spectra reveal that instead of producing unordered structure, unfolding converts turns and some helical elements to β-sheet. It also disrupts the Met80-heme bond, and was earlier shown to induce peroxidase activity. Aromatic residues that are H-bonded to a heme propionate (Trp59 and Tyr48) alter their orientation, indicating heme displacement. T-jump/UVRR measurements give time constants of 0.2, 3.9 and 67 µs for successive phases of β-sheet formation and concomitant reorientation of Trp59. UVRR spectra reveal protonation of histidines, and specifically of His26, whose H-bond to Pro44 anchors the 40s Ω loop; this loop is known to be the least stable ‘foldon’ in the protein. His26 protonation is proposed to disrupt its H-bond with Pro44, triggering the extension of a short β-sheet segment at the ‘neck’ of the 40s Ω loop into the loop itself and back into the 60’s and 70’s helices. The secondary structure change displaces the heme via H-bonds from residues in the growing β-sheet, thereby exposing it to exogenous ligands, and inducing peroxidase activity. This unfolding mechanism may play a role in cardiolipin peroxidation by cyt c during apoptosis.
Human thyroid stimulating hormone (TSH) is a glycoprotein secreted by the anterior part of the pituitary gland. TSH plays an important physiological role in the regulation of hypothalamic-pituitary-thyroid axis by modulating the release of the thyroid hormones from the thyroid gland. It induces iodine uptake by the thyroid, promotes thyroid epithelial differentiation and growth, and protects thyroid cells from apoptosis. Impairment of TSH signal transduction pathway leads to thyroid disorders such as goitre, hypothyroidism and hyperthyroidism, which can have complex clinical manifestations. TSH signaling is largely effected through two separate pathways, the adenylate cyclase and the phospholipase C pathways. In spite of its biomedical importance, a concise signaling map of TSH pathway is not available in the public domain. Therefore, we have generated a detailed signaling map of TSH pathway by systematically cataloging the molecular reactions induced by TSH including protein-protein interactions, post-translational modifications, protein translocation events and activation/inhibition reactions. We have cataloged 40 molecular association events, 42 enzyme-substrate reactions and 16 protein translocation events in TSH signaling pathway resource. Additionally, we have documented 208 genes, which are differentially regulated by TSH. We have provided the details of TSH pathway through NetPath (http://www.netpath.org), which is a publicly available resource for human signaling pathways developed by our group. We have also depicted the map of TSH signaling using NetSlim criteria (http://www.netpath.org/netslim/) and provided pathway maps in Wikipathways (http://www.wikipathways.org/). We anticipate that the availability of TSH pathway as a community resource will enhance further biomedical investigations into the function and effects of this important hormone.
Homeostasis; Basic Metabolic Rate; HPT Dysregulation; Camp; PKA; Osteoporosis; Cretinism; Myxedema; Thyrotoxicosis; Endocrine Signaling
The bioactivity of enzymes that are adsorbed on surfaces can be substantially influenced by the orientation of the enzyme on the surface and adsorption-induced changes in the enzyme’s structure. Circular dichroism (CD) is a powerful method for observing the secondary structure of proteins; however, it provides little information regarding the tertiary structure of a protein or its adsorbed orientation. In this study, we developed methods using side-chain specific chemical modification of solvent-exposed tryptophan residues to complement CD spectroscopy and bioactivity assays to provide greater detail regarding whether changes in enzyme bioactivity following adsorption are due to adsorbed orientation and/or adsorption-induced changes in the overall structure. These methods were then applied to investigate how adsorption influences the bioactivity of hen egg white lysozyme (HEWL) and glucose oxidase (GOx) on alkanethiol self-assembled monolayers (SAMs) over a range of surface chemistries. The results from these studies indicate that surface chemistry significantly influences the bioactive state of each of these enzymes, but in distinctly different ways. Changes in the bioactive state of HEWL are largely governed by its adsorbed orientation, while the bioactive state of adsorbed GOx is influenced by a combination of both adsorbed orientation and adsorption-induced changes in conformation.
Spectroscopic identification and characterization of covalent and non-covalent intermediates on large enzyme complexes is an exciting and challenging area of modern enzymology. The Escherichia coli pyruvate dehydrogenase multienzyme complex (PDHc), consisting of multiple copies of enzymic components and coenzymes, performs the oxidative decarboxylation of pyruvate to acetyl-CoA and is central to carbon metabolism linking glycolysis to the Krebs cycle. Based on earlier studies we hypothesized that the dynamic regions of the E1p component, which undergo a disorder-order transition upon substrate binding to thiamin diphosphate (ThDP), play a critical role in modulation of the catalytic cycle of PDHc. To test our hypothesis, we kinetically characterized ThDP-bound covalent intermediates on the E1p component, and the lipoamide-bound covalent intermediate on the E2p component in PDHc and in its variants with disrupted active-site loops. Our results suggest that formation of the first covalent pre-decarboxylation intermediate, C2α-lactylthiamin diphosphate (LThDP), is rate limiting for the series of steps culminating in acetyl-CoA formation. Substitutions in the active center loops produced variants with up to 900-fold lower rates of formation of the LThDP demonstrating that these perturbations directly affected covalent catalysis. This rate was rescued by up to 5-fold upon assembly to PDHc of the E401K variant. The E1p loop dynamics control covalent catalysis with ThDP and are modulated by PDHc assembly, presumably by selection of catalytically competent loop conformations. This mechanism could be a general feature of 2-oxoacid dehydrogenase complexes since such interfacial dynamic regions are highly conserved.