Endobronchial pseudo-tumour caused by herpes simplex.

Herpes simplex virus (HSV) causes tracheobronchitis and pneumonitis; however, to date, there has only been one report of an endobronchial mass caused by HSV type II. This case study describes a 68-yr-old female with severe kyphoscoliosis who was intubated for acute on chronic hypercapnic respiratory failure and developed blood-tinged endotracheal secretions. Fibreoptic bronchoscopy demonstrated an endobronchial mass in the right middle lobe. Cultures grew HSV type I and biopsy specimens demonstrated cytopathological changes consistent with HSV infection. This is the first reported case of HSV type I presenting as an endobronchial tumour.     

Tissue-associated self-antigens containing exosomes: Role in allograft rejection

Exosomes are extracellular vesicles that express self-antigens (SAgs) and donor human leukocyte antigens. Tissue-specific exosomes can be detected in the circulation following lung, heart, kidney and islet cell transplantations. We collected serum samples from patients who had undergone lung (n?=?30), heart (n?=?8), or kidney (n?=?15) transplantations to isolate circulating exosomes. Exosome purity was analyzed by Western blot, using CD9 exosome-specific markers. Tissue-associated lung SAgs, collagen V (Col-V) and K-alpha 1 tubulin (Kα1T), heart SAgs, myosin and vimentin, and kidney SAgs, fibronectin and collagen IV (Col-IV), were identified using western blot. Lung transplant recipients diagnosed with bronchiolitis obliterans syndrome had exosomes with higher expression of Col-V (4.2-fold) and Kα1T (37.1-fold) than stable. Exosomes isolated from heart transplant recipients diagnosed with coronary artery vasculopathy had a 3.9-fold increase in myosin and a 4.7-fold increase in vimentin compared with stable. Further, Kidney transplant recipients diagnosed with transplant glomerulopathy had circulating exosomes with a 2-fold increased expression of fibronectin and 2.5-fold increase in Col-IV compared with stable. We conclude that circulating exosomes with tissue associated SAgs have the potential to be a noninvasive biomarker for allograft rejection.     

Elucidation of the thromboregulatory role of CD39/ectoapyrase in the ischemic brain

Endothelial CD39 metabolizes ADP released from activated platelets. Recombinant soluble human CD39 (solCD39) potently inhibited ex vivo platelet aggregation in response to ADP and reduced cerebral infarct volumes in mice following transient middle cerebral artery occlusion, even when given 3 hours after stroke. Postischemic platelet and fibrin deposition were decreased and perfusion increased without increasing intracerebral hemorrhage. In contrast, aspirin did not increase postischemic blood flow or reduce infarction volume, but did increase intracerebral hemorrhage. Mice lacking the enzymatically active extracellular portion of the CD39 molecule were generated by replacement of exons 4-6 (apyrase-conserved regions 2-4) with a PGKneo cassette. Although CD39 mRNA 3' of the neomycin cassette insertion site was detected, brains from these mice lacked both apyrase activity and CD39 immunoreactivity. Although their baseline phenotype, hematological profiles, and bleeding times were normal, cd39(-/-) mice exhibited increased cerebral infarct volumes and reduced postischemic perfusion. solCD39 reconstituted these mice, restoring postischemic cerebral perfusion and rescuing them from cerebral injury. These data demonstrate that CD39 exerts a protective thromboregulatory function in stroke.     

Prevalence of acquired MDR-TB and HIV co-infection

BACKGROUND: Mounting prevalence of primary and acquired multidrug-resistant tuberculosis in India is a sorry reminder of all round failure in our fight against tuberculosis and also of the necessity for new effective strategies. OBJECTIVES: (1) To assess the prevalence and pattern of drug resistant pulmonary tuberculosis among treated patients or on those on treatment without adequate response and (2) to evaluate HIV seropositivity among MDR-TB patients. METHODS: Pulmonary TB patients, who had at least six months of unsuccessful anti-tuberculous treatment were selected for the study. Their sputum specimens were examined for M. tuberculosis culture and drug sensitivity pattern and serological examinations for HIV infection were carried out. RESULTS: Sputum specimens of 618 patients' (61.8%) of a total of 1000 examined had shown culturable M. tuberculosis. Four hundred ninty-five patients (49.5%) were found to expectorate tubercle bacilli resistant to one or more anti TB drugs. MDR-TB was detected in 339 patients (33.9%). HIV seropositivity among MDR-TB was 4.42%. Significantly, 245 patients (24.5%) had tubercle bacilli resistant to one or more reserve drugs too (ethionamide, kanamycin and/or ofloxacin). CONCLUSIONS: Prevalence of MDR-TB was high in the study population. It is essentially an acquired condition. Its association with HIV disease was at present on the lower side, an observation contrary to published western literature. Higher rates of resistance for reserve drugs (ethionamide, kanamycin and/or ofloxacin) in patients who never had these drugs in their earlier treatment schedules suggest the possibility of emerging spontaneous drug resistant mutants.     

Hierarchical recruitment of Plk4 and regulation of centriole biogenesis by two centrosomal scaffolds,Cep192 and Cep152

Centrosomes play an important role in various cellular processes, including spindle formation and chromosome segregation. They are composed of two orthogonally arranged centrioles, whose duplication occurs only once per cell cycle. Accurate control of centriole numbers is essential for the maintenance of genomic integrity. Although it is well appreciated that polo-like kinase 4 (Plk4) plays a central role in centriole biogenesis, how it is recruited to centrosomes and whether this step is necessary for centriole biogenesis remain largely elusive. Here we showed that Plk4 localizes to distinct subcentrosomal regions in a temporally and spatially regulated manner, and that Cep192 and Cep152 serve as two distinct scaffolds that recruit Plk4 to centrosomes in a hierarchical order. Interestingly, Cep192 and Cep152 competitively interacted with the cryptic polo box of Plk4 through their homologous N-terminal sequences containing acidic-α-helix and N/Q-rich motifs. Consistent with these observations, the expression of either one of these N-terminal fragments was sufficient to delocalize Plk4 from centrosomes. Furthermore, loss of the Cep192- or Cep152-dependent interaction with Plk4 resulted in impaired centriole duplication that led to delayed cell proliferation. Thus, the spatiotemporal regulation of Plk4 localization by two hierarchical scaffolds, Cep192 and Cep152, is critical for centriole biogenesis.The centrosome is the main microtubule-organizing center in mammalian cells that plays a central role in spindle formation and chromosome segregation during mitosis. Centrosomes are composed of two orthogonally arranged centrioles surrounded by an amorphous mass of electron-dense pericentriolar material (PCM). Centrioles duplicate precisely once per cell cycle and serve as platforms for the assembly of centrosomes, primary cilia, and flagella (1–4).Centriole duplication is initiated by the assembly of a procentriole in early S phase. In Caenorhabditis elegans, a centrosomal scaffold protein, called Spd-2, is required for proper recruitment of a Ser/Thr kinase, Zyg-1 (5), to centrosomes, and this step in turn allows the recruitment of Sas-6, Sas-5, and Sas-4 to the site of procentriole assembly (6, 7). Sas6 plays a pivotal role in self-assembling a cartwheel-like structure at this site of the procentriole with Sas5 and Sas4 (8–12). In Drosophila, the overexpression of polo-like kinase 4 (Plk4; also called Sak), the Zyg-1 ortholog, is sufficient to induce centriole amplification, whereas the depletion of Plk4 disrupts centriole duplication (12, 13). Interestingly, however, Drosophila Spd-2 is dispensable for Plk4-mediated centriole duplication (14). Instead, another scaffold, Asterless, has been suggested to play a critical role in targeting Plk4 to centrosomes (15), hinting that the mechanism underlying Plk4 recruitment is distinct in different organisms.Accumulated evidence in humans suggests that Plk4 is a functional ortholog of C. elegans Zyg-1 and Drosophila Plk4, and that it plays a key role in centriole duplication (16, 17). When overexpressed, Plk4 can induce multiple centriole precursors surrounding a single parental centriole, and centrosomally localized Plk4 appears to be required for this event (16). The cryptic polo box (CPB) present at the upstream of the C-terminal polo box (PB) (18) is necessary and sufficient for targeting Plk4 to centrosomes (16, 19). Interestingly, the CPB comprises two structurally related motifs and forms a homodimer (19) to interact with its binding targets. However, the molecular basis of how Plk4 binds to its targets and localizes to centrosomes remains largely elusive.Studies have shown that Cep152, a human ortholog of Drosophila Asterless, interacts with Plk4 through the CPB (20, 21). However, the depletion of Cep152 does not significantly decrease the level of Plk4 at centrosomes. Recently, Sonnen et al. have shown that a C. elegans Spd-2 ortholog, Cep192, interacts with Plk4 and promotes the recruitment of Plk4 to centrosomes (22). Moreover, Cep192 binds to Cep152, and the depletion of both enhances the Plk4 localization defect (22). Based on these observations, Sonnen et al. proposed that Cep192 cooperates with Cep152 to properly recruit Plk4 to centrosomes and to promote centriole duplication (22).In this study, we demonstrated that disrupting either the Cep192–Plk4 interaction or the Cep152–Plk4 interaction was sufficient to impair centriole duplication. We further showed that Plk4 dynamically localizes to different subcentrosomal regions in a cell cycle-specific manner, and that Cep192 functions at a point upstream of Cep152 to regulate Plk4 localization. Thus, we propose that the spatiotemporal regulation of Plk4 localization by two hierarchical scaffolds, Cep192 and Cep152, is critical for Plk4-dependent centriole biogenesis.     

Crystallization and preliminary x-ray diffraction analysis of P450terp and the hemoprotein domain of P450BM-3, enzymes belonging to two distinct classes of the cytochrome P450 superfamily.

Cytochromes P450 are members of a superfamily of hemoproteins that are involved in the metabolism of various physiologic and xenobiotic organic compounds. This superfamily of proteins can be divided into two classes based on the electron donor proximal to the P450: an iron-sulfur protein for class I P450s or a flavoprotein for class II. The only known tertiary structure of any of the cytochromes P450 is that of P450cam, a class I soluble enzyme isolated from Pseudomonas putida (product of the CYP101 gene). To understand the details of the structure-function relationships within and between the two classes, structural studies on additional cytochromes P450 are crucial. We report here characterization of the crystal forms of two soluble, bacterial enzymes: cytochrome P450terp [class I enzyme from a Pseudomonas species (product of CYP108 gene)] and the hemoprotein domain of cytochrome P450BM-3 [class II enzyme from Bacillus megaterium (product of the CYP102 gene)]. The crystals of cytochrome P450terp are hexagonal and belong to the space group P6(1)22 (or its enantiomorph, P6(5)22) with unit cell dimensions a = b = 68.9 A and c = 458.7 A. The crystals of the hemoprotein domain of cytochrome P450BM-3 are monoclinic and belong to the space group P2(1) with unit cell dimensions a = 59.4 A, b = 154.0 A, c = 62.2 A, and beta = 94.7 degrees. Diffraction data for the crystals of these two proteins were obtained to a resolution better than 2.2 A. Assuming the presence of two molecules in the asymmetric unit for the hemoprotein domain of P450BM-3 and one molecule for P450terp, the calculated values of Vm are 2.6 and 3.3 A3/Da, respectively.     

Quantitative assessment of circulating antigens in human lymphatic filariasis: a field evaluation of monoclonal antibody-based ELISA using blood collected on filter strips

objective   To quantify circulating antigens in individuals with lymphatic filariasis by means of an ELISA using blood on filter strips. method   Circulating antigens in filarial patients and normal individuals living in an area endemic for W. bancrofti infection in Madras, India were estimated using a monoclonal antibody-based ELISA. results   All microfilaraemics showed positivity to circulating antigens whereas people with chronic pathology and 80% of the endemic normals tested negative. The antigen levels in the blood collected in the night and during day time showed positivity and there was no difference in the antigen concentration. The results of the antigen levels collected onto filter strips correlated with their corresponding plasma antigen levels ( r = 0.83). In microfilaraemics, DEC treatment did not alter the levels of circulating antigens for up to one month. conclusions   We conclude that this monoclonal antibody-based ELISA using filter strips may be used in day time and replace the existing routine night blood surveys in our endemic area in India.     

Modified Girdlestones-Taylor procedure for claw toes in spinal cord injury

STUDY DESIGN: A combination of review of case notes and outpatient follow-up. OBJECTIVE: To evaluate the effectiveness of the modified Girdlestones-Taylor procedure in patients with spinal cord injury (SCI). SETTING: Princess Royal Spinal Injuries Centre (PRSIC), Northern General Hospital, Sheffield, UK. METHODS: Nine patients with claw toe deformities to 27 toes were treated at the PRSIC from 1996 to 2005. After examination of their medical records, their toes were assessed for pain, residual deformity and stiffness. They were also asked to grade their satisfaction with the surgical outcome. The results were tabulated. RESULTS: The average age of our series of patients was 43.3 years. The mean time from injury to surgery was 20.4 years and the mean time from surgery to last follow-up was 37.3 months. All our patients had good to excellent results, with over 70% of the toes having excellent results. CONCLUSION: The modified Girdlestones-Taylor procedure for claw toe correction appears to be a safe and effective treatment for patients with SCI.     

CENTRAL PANCREATECTOMY FOR BENIGN PANCREATIC PATHOLOGY/TRAUMA: IS IT A REASONABLE PANCREAS‐PRESERVING CONSERVATIVE SURGICAL STRATEGY ALTERNATIVE TO STANDARD MAJOR PANCREATIC RESECTION?

BACKGROUND: The aim of this study was to assess the technical feasibility, safety and outcome of central pancreatectomy (CP) with pancreaticogastrostomy or pancreaticojejunostomy in appropriately selected patients with benign central pancreatic pathology/trauma. Benign lesions/trauma of the pancreatic neck and proximal body pose an interesting surgical challenge. CP is an operation that allows resection of benign tumours located in the pancreatic isthmus that are not suitable for enucleation. METHODS: Between January 2000 and December 2005, eight central pancreatectomies were carried out. There were six women and two men with a mean age of 35.7 years. The cephalic pancreatic stump is oversewn and the distal stump is anastomosed end-to-end with a Roux-en-Y jejunal loop in two and with the stomach in six patients. The indications for CP were: non-functional islet cell tumours in two patients, traumatic pancreatic neck transection in two and one each for insulinoma, solid pseudopapillary tumour, splenic artery pseudoaneurysm and pseudocyst. Pancreatic exocrine function was evaluated by a questionnaire method. Endocrine function was evaluated by blood glucose level. RESULTS: Morbidity rate was 37.5% with no operative mortality. Mean postoperative hospital stay was 10.5 days. Neither of the patients developed pancreatic fistula nor required reoperations or interventional radiological procedures. At a mean follow up of 26.4 months, no patient had evidence of endocrine or exocrine pancreatic insufficiency, all the patients were alive and well without clinical and imaging evidence of disease recurrence. CONCLUSION: When technically feasible, CP is a safe, pancreas-preserving pancreatectomy for non-enucleable benign pancreatic pathology/trauma confined to pancreatic isthmus that allows for cure of the disease without loss of substantial amount of normal pancreatic parenchyma with preservation of exocrine/endocrine function and without interruption of enteric continuity.