Two-component regulatory system TCS08 of a serotype 4 strain in pneumococcal pneumonia pathogenesis.

OBJECTIVES: Streptococcus pneumoniae, a human respiratory pathogen, causes diseases with severe morbidity and mortality rates worldwide. The two-component regulatory system (TCS) is an important signaling pathway that enables regulation of gene expression in response to environmental cues, thereby allowing an organism to adapt to a variety of host niches. Here we examined the contribution of pneumococcal TCS08 to bacterial colonization, the development of pneumonia, and pulmonary dysfunction. METHODS: We employed an hk08 knockout mutant (Δhk08) with a background of the TIGR4 wild-type (WT) strain to verify whether TCS08 is associated with bacterial colonization and the development of pneumonia in a murine infection model. To clarify the association of hk08 inactivation-induced phenotypic changes with their virulence, we examined pneumococcal capsule production, colony morphology, and surface-displayed protein profiles. RESULTS: Pneumococcal TCS08 was involved in bacterial colonization in the respiratory tract. Interruption of the signaling pathway of TCS08 by hk08 inactivation impaired mouse survival and increased the bacterial burden within the respiratory tract. Furthermore, a histopathological examination revealed massive inflammatory cell infiltration, edema formation, and diffuse alveolar damage in the lung tissues of mice infected with Δhk08 versus the WT or complemented strain. Interestingly, virulence-associated phenotype changes, including capsule production, increased chain length, and surface-displayed protein profile, were observed in the Δhk08 strain. CONCLUSIONS: The present findings indicate that TCS08 contributes to pneumococcal colonization and pulmonary dysfunction by assisting adaptation to the respiratory tract milieu, leading to the development of pneumonia.

Remote electronic effect on the N-heterocyclic carbene-catalyzed asymmetric intramolecular Stetter reaction and structural revision of products.

The remote electronic effects of chiral N-heterocyclic carbene catalysts on the asymmetric intramolecular Stetter reaction are investigated. The reaction rate and enantioselectivity were markedly influenced by a substituent at a remote position of the catalyst. The absolute configurations of the products are revised on the basis of X-ray diffraction. Density-functional theory calculations rationalize the improvement of the enantioselectivity using an electron-deficient catalyst.

Construction of Human Three-Dimensional Lung Model Using Layer-by-Layer Method.

The respiratory tract is one of the frontline barriers for biological defense. Lung epithelial intercellular adhesions provide protection from bacterial and viral infections and prevent invasion into deep tissues by pathogens. Dysfunction of lung epithelial intercellular adhesion caused by pathogens is associated with development of several diseases, such as acute respiratory distress syndrome, pneumonia, and asthma. To elucidate the pathological mechanism of respiratory infections, two-dimensional cell cultures and animal models are commonly used, although are not useful for evaluating host specificity or human biological response. With the rapid progression and worldwide spread of severe acute respiratory syndrome coronavirus-2, there is increasing interest in the development of a three-dimensional (3D) in vitro lung model for analyzing interactions between pathogens and hosts. However, some models possess unclear epithelial polarity or insufficient barrier functions and need the use of complex technologies, have high cost, and long cultivation terms. We previously reported about the fabrication of 3D cellular multilayers using a layer-by-layer (LbL) cell coating technique with extracellular matrix protein, fibronectin (FN), and gelatin (G). In the present study, such a LbL cell coating technique was utilized to construct a human 3D lung model in which a monolayer of the human lower airway epithelial adenocarcinoma cell line Calu-3 cells was placed on 3D-cellular multilayers composed of FN-G-coated human primary pulmonary fibroblast cells. The 3D lung model thus constructed demonstrated an epithelial-fibroblast layer that maintained uniform thickness until 7 days of incubation. Moreover, expressions of E-cadherin, ZO-1, and mucin in the epithelial layer were observed by immunohistochemical staining. Epithelial barrier integrity was evaluated using transepithelial electrical resistance values. The results indicate that the present constructed human 3D lung model is similar to human lung tissues and also features epithelial polarity and a barrier function, thus is considered useful for evaluating infection and pathological mechanisms related to pneumonia and several pathogens. Impact statement A novel in vitro model of lung tissue was established. Using a layer-by-layer cell coating technique, a three-dimensional cultured lung model was constructed. The present novel model was shown to have epithelial polarity and chemical barrier functions. This model may be useful for investigating interaction pathogens and human biology.

GP96 Drives Exacerbation of Secondary Bacterial Pneumonia following Influenza A Virus Infection.

Influenza A virus (IAV) infection predisposes the host to secondary bacterial pneumonia, known as a major cause of morbidity and mortality during influenza virus epidemics. Analysis of interactions between IAV-infected human epithelial cells and Streptococcus pneumoniae revealed that infected cells ectopically exhibited the endoplasmic reticulum chaperone glycoprotein 96 (GP96) on the surface. Importantly, efficient pneumococcal adherence to epithelial cells was imparted by interactions with extracellular GP96 and integrin αV, with the surface expression mediated by GP96 chaperone activity. Furthermore, abrogation of adherence was gained by chemical inhibition or genetic knockout of GP96 as well as addition of RGD peptide, an inhibitor of integrin-ligand interactions. Direct binding of extracellular GP96 and pneumococci was shown to be mediated by pneumococcal oligopeptide permease components. Additionally, IAV infection induced activation of calpains and Snail1, which are responsible for degradation and transcriptional repression of junctional proteins in the host, respectively, indicating increased bacterial translocation across the epithelial barrier. Notably, treatment of IAV-infected mice with the GP96 inhibitor enhanced pneumococcal clearance from lung tissues and ameliorated lung pathology. Taken together, the present findings indicate a viral-bacterial synergy in relation to disease progression and suggest a paradigm for developing novel therapeutic strategies tailored to inhibit pneumococcal colonization in an IAV-infected respiratory tract. IMPORTANCE Secondary bacterial pneumonia following an influenza A virus (IAV) infection is a major cause of morbidity and mortality. Although it is generally accepted that preceding IAV infection leads to increased susceptibility to secondary bacterial infection, details regarding the pathogenic mechanism during the early stage of superinfection remain elusive. Here, we focused on the interaction of IAV-infected cells and Streptococcus pneumoniae, which revealed that human epithelial cells infected with IAV exhibit a cell surface display of GP96, an endoplasmic reticulum chaperon. Notably, extracellular GP96 was shown to impart efficient adherence for secondary infection by S. pneumoniae, and GP96 inhibition ameliorated lung pathology of superinfected mice, indicating it to be a useful target for development of therapeutic strategies for patients with superinfection.

Efficacy and safety of lanthanum carbonate in pre-dialysis CKD patients with hyperphosphatemia: a randomized trial.

BACKGROUND: Lanthanum carbonate (LC), an effective non-calcium phosphate binder is widely used to manage hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis. Recently, the additional indication for control of hyperphosphatemia in CKD patients not on dialysis has been approved. METHODS: A multicenter, randomized, double-blind, placebo-controlled trial to confirm the efficacy and safety of LC in Japanese hyperphosphatemic stage 4 - 5 CKD patients not on dialysis. After a 4-week run-in period, 143 eligible subjects with serum phosphate levels of 5.6 - 11.0 mg/dL were randomized (2 : 1) to receive LC or placebo (88 vs. 55) for 8 weeks; 119 subjects completed the study (76 vs. 43). The starting LC dose was 750 mg/day, which was then up-titrated to 2,250 mg/day as needed while tolerated. Primary efficacy analysis was performed on the intent-to-treat (ITT) population of 141 patients (86 vs. 55). RESULTS: LC produced a significantly greater reduction in serum phosphate level compared with placebo after 8 weeks of treatment (difference, 0.97 (95% CI: 0.58, 1.37) mg/ dL; p < 0.0001). The cumulative proportion of subjects with controlled phosphate levels ≤ 4.6 mg/dL was higher in the LC group than the placebo group (59.56% vs. 10.46%). LC caused significantly greater reductions in serum Ca × P product and urinary phosphate excretion compared with placebo. The safety profile of LC was similar to that of placebo. CONCLUSIONS: This study demonstrated the effectiveness of LC to control hyperphosphatemia in pre-dialysis CKD patients.

Expression of pancreatitis associated proteins in urothelium and urinary afferent neurons following cyclophosphamide induced cystitis.

PURPOSE: We examined the expression profile of the members of the pancreatitis associated proteins/regenerating gene family in the bladder and in the primary afferent neurons of dorsal root ganglia using an animal model of cystitis. MATERIALS AND METHODS: We examined the expression of pancreatitis-associated protein-I and pancreatitis-associated protein-III in the bladder and the dorsal root ganglia of female rats 4 hours, 48 hours or 10 days after cyclophosphamide (Sigma) injection using immunohistochemistry and reverse transcriptase-polymerase chain reaction. RESULTS: No pancreatitis-associated protein-III immunoreactivity was identified in control bladders but prominent expression was observed in the urothelium of animals with chronic cystitis. Cells expressing pancreatitis-associated protein-I were seen in the dorsal root ganglia but not in the bladder. In normal dorsal root ganglia pancreatitis-associated protein-I was expressed in a minor population of small diameter neurons (2.4%) that were also positive for isolectin-B4. However, by 10 days following the onset of cystitis the number of pancreatitis-associated protein-I positive neurons was increased (7.6%) and pancreatitis-associated protein-I immunoreactivity was further observed in a slightly larger group of neurons and tyrosine kinase A positive small neurons. CONCLUSIONS: The current results suggest that pancreatitis-associated protein-III is associated with bladder inflammation and they implicate pancreatitis-associated protein-I in the abnormal sensation in cystitis.

Transient suppression of the vesicular acetylcholine transporter in urinary bladder pathways following spinal cord injury.

The aim of this study was to examine the expression profile of the vesicular acetylcholine transporter (VAChT), which is a cholinergic pre-synaptic marker, in the lower neural tract following spinal cord injury (SCI) and its effect on coordination of micturition. In adult female Sprague-Dawley rats, SCI was induced by complete transection of the spinal cord at T9. At various time points, 3, 7, 14 and 28 days, after SCI, cystometry was performed on conscious rats. Bladder areflexia was observed during the first week. Twenty-eight days after SCI the rats showed reflex contractions and voiding. The expression of VAChT was examined with immunohistochemistry. The number of VAChT-positive nerve terminals, which were surrounding neuronal soma, was transiently decreased in pelvic ganglion and spinal cord (L1, L2, L6 and S1). In particular VAChT terminals surrounding motor neurons in the ventral horn and autonomic pre-ganglion cells were dramatically decreased from 3 to 14 days after SCI. Similarly, and the number of VAChT-positive fibers in the bladder wall was also decreased. The intensity of VAChT terminals recovered in all above regions in conjunction with recovery of bladder function. These observations indicate that the transient decrease of the VAChT-positive nerve might cause a failure of cholinergic neuronal transmission along the urinary bladder tract after SCI. As the cholinergic system was recovered at least in rat, the functional recovery of neurogenic bladder syndrome in SCI patients may become possible by further understanding the mechanism underlying the recovery of cholinergic system in rat.

Targeted gene therapy toward astrocytoma using a Cre/loxP-based adenovirus system.

The aim of this study was to establish a novel adenovirus-based gene therapy system targeting astrocytoma. For this purpose, the Cre recombinase (Cre)/loxP system together with the astrocytoma-specific promoter for GFAP were used. We constructed an adenovirus (Ad) vector that expressed Cre under the control of the GFAP promoter (AxGFAPNCre), as well as another Ad vector containing a switching unit. The latter vector contained a stuffer sequence encoding GFP (AxCALGLTK) with a functional polyadenylation signal between two loxP sites, followed by the herpes simplex virus thymidine kinase (HSV-TK) gene under the control of the CAG promoter. In this system, gene expression of either the stuffer sequence (GFP) or the downstream gene (HSV-TK) was switched on by co-expression of Cre recombinase. Western blot analysis demonstrated specific expression of high levels of TK protein in C6 glioma cells after co-infection of AxGFAPNCre and AxCALGLTK. In vivo, AxGFAPNCre/AxCALGLTK injection into C6 gliomas in the subcutaneous tissue of nude mice followed by intraperitoneal ganciclovir (GCV) treatment significantly suppressed tumor growth compared with control mice. Co-infection of AxGFAPNCre and AxCALNLLacZ resulted in LacZ expression in C6 glioma cells and some reactive astrocytes, whereas GFP was expressed in other cell types surrounding the injected site. Furthermore, a combination of AxGFAPNCre/AxCALGLTK and intraperitoneal GCV injection significantly regressed intracranial C6 gliomas in the rat striatum and prolonged the survival time compared with control rats. The present results indicate that this cell-type-specific gene therapy using a Cre/loxP adenovirus system is both operational and effective, at least against astrocytoma.

[Primary mucosa-associated lymphoid tissue (MALT) lymphoma of the urinary bladder].

A 85-year-old woman presented with macroscopic hematuria and miction pain. Cystoscopy revealed a wide-based submucosal mass, and biopsied specimens of the mass showed a B-cell lymphoma of the MALT type. Computed tomography (CT) showed a 7.5 x 3.0 cm solitary mass lesion situated from the anterior wall to the right lateral bladder wall, and magnetic resonance imaging (MRI) showed a low intensity in T1W1, high in T2W1 without invasion. After she was admitted to our hospital, TUR of the lesion was performed. The findings were consistent with extranodal marginal zone B-cell lymphoma of the MALT type. No evidence of lymphoma was found on the CT of the pelvis, chest X-ray and Gallium scintigraphy. The patient had stages I(AE) lymphoma. The patient was treated with radiation therapy to the bladder and pelvis (40 Gy in 20 fractions) and was followed with CT every 3 months. She had no evidence of recurrance.

The importance of studying pressure-flow for predicting postoperative voiding difficulties in women with stress urinary incontinence: a preliminary study that correlates low Pdet x Qave with postoperative residual urine.

We evaluated the parameters of preoperative pressure-flow for predicting the postoperative voiding difficulties in women with stress urinary incontinence. The preoperative urodynamic study records of 14 women treated using the tension-free vaginal tape (TVT) procedure were retrospectively analyzed. Of the patients treated with the TVT procedure, urinary retention occurred in one patient, and three had a residual urine volume of more than 30 ml. All patients became completely free of stress urinary incontinence postoperatively. The lowest Pdet max (5 cmH(2)O) in the preoperative pressure-flow study was found in a patient with a remarkable postoperative residual urine volume of more than 50 ml. The second lowest Pdet max value (8 cmH(2)O) was seen in a patient with postoperative urinary retention, whose residual urine volume, however, decreased to almost zero 1 year after the operation. The preoperative Pdet max x Qave values were remarkably low for these three patients, including the one with the lowest Pdet max, with a post-void residual urine volume of more than 30 ml. The plots of Pdet max x Qave versus the age of patients show that the Pdet max x Qave values tend to decrease with aging. The preoperative Pdet max x Qave value can be an important parameter for predicting increased residual urine after TVT sling surgery.

Renal transplantation for the hemodialysis patient with axillofemoral bypass.

BACKGROUND: Axillofemoral bypass grafts are used in the treatment of aortoiliac occlusive disease caused by atherosclerosis. There have been no previous reports on renal transplantation used as treatment for chronic renal failure after an axillofemoral bypass graft being placed because of atypical coarctation of the aorta. METHODS: The patient was a 47-year-old woman who had received regular hemodialysis for 15 years. Axillofemoral bypass surgery was performed because of atypical coarctation of the aorta in October 1999. Three years after surgery, she underwent renal transplantation. RESULTS: Renal transplantation was successful, and helical computed tomography demonstrated patent graft bypass and good nephrographic effects of the renal artery. CONCLUSIONS: Even though dialysis patients with atypical coarctation of the aorta are treated with an axillofemoral bypass, it is possible for them to undergo regular renal transplantation, if part of the external or internal iliac artery is intact.

A novel steroid receptor co-activator protein (SRAP) as an alternative form of steroid receptor RNA-activator gene: expression in prostate cancer cells and enhancement of androgen receptor activity.

We have cloned a cDNA coding for a novel steroid receptor co-activator protein termed SRAP from a rat prostate library. Although the nucleotide sequence of the SRAP has 78.2% identity to that of the human steroid receptor RNA activator (SRA), a novel RNA molecule which was reported to act as an RNA transcript without being translated into protein [Lanz, McKenna, Onate, Albrecht, Wong, Tsai, Tsai and O'Malley (1999) Cell 97, 17-27], the cDNA of SRAP is capable of generating a functional protein. Glutathione S-transferase pull-down assays showed that SRAP associates with the partial androgen receptor (AR) protein composed of a DNA-binding domain and an activation function 2. Luciferase assays demonstrated that SRAP enhances the transactivation activity of the AR, the glucocorticoid receptor and the peroxisome proliferator-activated receptor gamma(1) in a ligand-dependent manner. Using a green fluorescent protein (GFP) fusion-protein construct, we demonstrated in vivo translation of the GFP-SRAP fusion protein in HeLa cells co-transfected with pSG5AR and reporter gene in the presence of 5 alpha-dihydrotestosterone (DHT). Co-transfection of the GFP-SRAP fusion protein expression plasmid enhanced the transactivation activity of AR whereas incorporation of mutations in SRAP of the fusion protein resulted in loss of enhancement of the transactivation activity. Northern blot analysis and reverse transcriptase PCR assays showed that SRAP and SRA are expressed in rat and human prostate cancer cell lines respectively. In HeLa cells and the human prostate cancer cells line DU-145, co-transfected with SRAP, the DHT-dependent transactivation activities of AR were not completely inhibited by the anti-androgen flutamide, but the transactivation activities still remained high even in the presence of 5 microM flutamide, suggesting that SRAP may play an important role in enhancing AR activity in prostate cancer.