Escherichia coli SPFH Membrane Microdomain Proteins HflKC Contribute to Aminoglycoside and Oxidative Stress Tolerance

Many eukaryotic membrane-dependent functions are often spatially and temporally regulated by membrane microdomains (FMMs), also known as lipid rafts. These domains are enriched in polyisoprenoid lipids and scaffolding proteins belonging to the stomatin, prohibitin, flotillin, and HflK/C (SPFH) protein superfamily that was also identified in Gram-positive bacteria. In contrast, little is still known about FMMs in Gram-negative bacteria. In Escherichia coli K-12, 4 SPFH proteins, YqiK, QmcA, HflK, and HflC, were shown to localize in discrete polar or lateral inner membrane locations, raising the possibility that E. coli SPFH proteins could contribute to the assembly of inner membrane FMMs and the regulation of cellular processes. Here, we studied the determinant of the localization of QmcA and HflC and showed that FMM-associated cardiolipin lipid biosynthesis is required for their native localization pattern. Using Biolog phenotypic arrays, we showed that a mutant lacking all SPFH genes displayed increased sensitivity to aminoglycosides and oxidative stress that is due to the absence of HflKC. Our study therefore provides further insights into the contribution of SPFH proteins to stress tolerance in E. coli. IMPORTANCE Eukaryotic cells often segregate physiological processes in cholesterol-rich functional membrane microdomains. These domains are also called lipid rafts and contain proteins of the stomatin, prohibitin, flotillin, and HflK/C (SPFH) superfamily, which are also present in prokaryotes but have been mostly studied in Gram-positive bacteria. Here, we showed that the cell localization of the SPFH proteins QmcA and HflKC in the Gram-negative bacterium E. coli is altered in the absence of cardiolipin lipid synthesis. This suggests that cardiolipins contribute to E. coli membrane microdomain assembly. Using a broad phenotypic analysis, we also showed that HflKC contribute to E. coli tolerance to aminoglycosides and oxidative stress. Our study, therefore, provides new insights into the cellular processes associated with SPFH proteins in E. coli.

Intermittent antibiotic treatment of bacterial biofilms favors the rapid evolution of resistance

Bacterial antibiotic resistance is a global health concern of increasing importance and intensive study. Although biofilms are a common source of infections in clinical settings, little is known about the development of antibiotic resistance within biofilms. Here, we use experimental evolution to compare selection of resistance mutations in planktonic and biofilm Escherichia coli populations exposed to clinically relevant cycles of lethal treatment with the aminoglycoside amikacin. Consistently, mutations in sbmA, encoding an inner membrane peptide transporter, and fusA, encoding the essential elongation factor G, are rapidly selected in biofilms, but not in planktonic cells. This is due to a combination of enhanced mutation rate, increased adhesion capacity and protective biofilm-associated tolerance. These results show that the biofilm environment favors rapid evolution of resistance and provide new insights into the dynamic evolution of antibiotic resistance in biofilms.

Detection of bacterial DNA from central venous catheter removed from patients by next generation sequencing: a preliminary clinical study

BACKGROUND

Catheter-related infection (CRI) is one of the serious challenges in clinical practice. This preliminary clinical study aimed to examine whether next-generation sequencing (NGS) targeting 16S rDNA, which was PCR-amplified directly from the tip of a central venous catheter (CVC), can be used to identify causative pathogens in CRI, compared to the culture method.

METHODS

Hospitalized patients, from whom a CVC had just been removed, were prospectively enrolled and divided into the CRI-suspected and routine removal groups. DNA was extracted from the sonication fluid of CVC specimens derived from patients. For analysis of bacterial composition by NGS, the V3-V4 fragments of bacterial 16S rDNA were PCR-amplified, followed by index PCR and paired-end sequencing on an Illumina MiSeq device. Conventional culture methods were also performed in the CRI-suspected group.

RESULTS

Of CVCs collected from the 156 enrolled patients (114 men; mean age 65.6 years), a total of 14 specimens [nine out of 31 patients suspected with CRI and five out of 125 patients without infection symptoms (routine removal group)] were PCR-positive. In five patients with definite CRI, Staphylococcus was the most frequently detected genus by NGS (4/5 specimens), although no pathogens were detected by NGS in the one remaining specimen. The genera identified by NGS were consistent with those from conventional culture tests. There was high agreement between NGS and the culture method in the CRI-suspected group, with sensitivity and specificity values of 80.0% and 76.9%, respectively; meanwhile, the false-positive rate of NGS was as low as 4.0% in the routine removal group. Moreover, several genera, besides the genus identified by culture test, were detected in each patient with definite CRI and surgical site infection (SSI). Additionally, in one patient with SSI, Enterococcaceae were detected not only by NGS but also by abdominal abscess drainage culture.

CONCLUSIONS

NGS targeting 16S rDNA was able to analyze the bacterial composition of CVC specimens and detect causative pathogens in patients with CRI and was therefore suggested as a promising diagnostic tool for CRI.

Norgestimate inhibits staphylococcal biofilm formation and resensitizes methicillin-resistant Staphylococcus aureus to β-lactam antibiotics

Formation of bacterial biofilms on medical devices can cause severe or fatal infectious diseases. In particular, biofilm-associated infections caused by methicillin-resistant Staphylococcus aureus are difficult to eradicate because the biofilm is strongly resistant to antibiotics and the host immune response. There is no effective treatment for biofilm-associated infectionss, except for surgical removal of contaminated medical devices followed by antibiotic therapy. Here we show that norgestimate, an acetylated progestin, effectively inhibits biofilm formation by staphylococcal strains, including methicillin-resistant S. aureus, without inhibiting their growth, decreasing the selective pressure for emergence of resistance. 17-Deacetyl norgestimate, a metabolite of norgestimate, shows much weaker inhibitory activity against staphylococcal biofilm formation, indicating that the acetyl group of norgestimate is important for its activity. Norgestimate inhibits staphylococcal biofilm formation by inhibiting production of polysaccharide intercellular adhesin and proteins in the extracellular matrix. Proteome analysis of S. aureus indicated that norgestimate represses the expression of the cell wall-anchored protein SasG, which promotes intercellular adhesion, and of the glycolytic enzyme enolase, which plays a secondary role in biofilm formation. Notably, norgestimate induces remarkable changes in cell wall morphology, characterized by increased thickness and abnormal rippled septa. Furthermore, norgestimate increases the expression level of penicillin binding protein 2 and resensitizes methicillin-resistant S. aureus to β-lactam antibiotics. These results suggest that norgestimate is a promising lead compound for the development of drugs to treat biofilm-associated infections, as well as for its ability to resensitize methicillin-resistant S. aureus to β-lactam antibiotics.

A synthetic molecule related to the hormone progesterone might keep medical devices free of biofilms without promoting antibiotic resistance. Implanted devices that have become contaminated with biofilms generally must be surgically removed prior to treating the underlying infection with antibiotics. Ken-ichi Okuda and colleagues at The Jikei University School of Medicine in Tokyo, with co-workers elsewhere in Japan, found that the synthetic progesterone analog norgestimate inhibits biofilm formation without inhibiting bacterial growth. They regard this selective effect on biofilm formation as a significant advantage, as it reduces the risk of inducing resistance in the targeted bacteria. They demonstrated the effect using staphylococcal bacteria, including the problematic and highly dangerous methicillin-resistant Staphylococcus aureus (MRSA). The research also indicated that norgestimate can resensitize MRSA bacteria to some of the antibiotics they are resistant to.

Azithromycin attenuates myofibroblast differentiation and lung fibrosis development through proteasomal degradation of NOX4

Accumulation of profibrotic myofibroblasts is involved in the process of fibrosis development during idiopathic pulmonary fibrosis (IPF) pathogenesis. TGFB (transforming growth factor β) is one of the major profibrotic cytokines for myofibroblast differentiation and NOX4 (NADPH oxidase 4) has an essential role in TGFB-mediated cell signaling. Azithromycin (AZM), a second-generation antibacterial macrolide, has a pleiotropic effect on cellular processes including proteostasis. Hence, we hypothesized that AZM may regulate NOX4 levels by modulating proteostasis machineries, resulting in inhibition of TGFB-associated lung fibrosis development. Human lung fibroblasts (LF) were used to evaluate TGFB-induced myofibroblast differentiation. With respect to NOX4 regulation via proteostasis, assays for macroautophagy/autophagy, the unfolded protein response (UPR), and proteasome activity were performed. The potential anti-fibrotic property of AZM was examined by using bleomycin (BLM)-induced lung fibrosis mouse models. TGFB-induced NOX4 and myofibroblast differentiation were clearly inhibited by AZM treatment in LF. AZM-mediated NOX4 reduction was restored by treatment with MG132, a proteasome inhibitor. AZM inhibited autophagy and enhanced the UPR. Autophagy inhibition by AZM was linked to ubiquitination of NOX4 via increased protein levels of STUB1 (STIP1 homology and U-box containing protein 1), an E3 ubiquitin ligase. An increased UPR by AZM was associated with enhanced proteasome activity. AZM suppressed lung fibrosis development induced by BLM with concomitantly reduced NOX4 protein levels and enhanced proteasome activation. These results suggest that AZM suppresses NOX4 by promoting proteasomal degradation, resulting in inhibition of TGFB-induced myofibroblast differentiation and lung fibrosis development. AZM may be a candidate for the treatment of the fibrotic lung disease IPF.

Pirfenidone inhibits myofibroblast differentiation and lung fibrosis development during insufficient mitophagy

Background

Pirfenidone (PFD) is an anti-fibrotic agent used to treat idiopathic pulmonary fibrosis (IPF), but its precise mechanism of action remains elusive. Accumulation of profibrotic myofibroblasts is a crucial process for fibrotic remodeling in IPF. Recent findings show participation of autophagy/mitophagy, part of the lysosomal degradation machinery, in IPF pathogenesis. Mitophagy has been implicated in myofibroblast differentiation through regulating mitochondrial reactive oxygen species (ROS)-mediated platelet-derived growth factor receptor (PDGFR) activation. In this study, the effect of PFD on autophagy/mitophagy activation in lung fibroblasts (LF) was evaluated, specifically the anti-fibrotic property of PFD for modulation of myofibroblast differentiation during insufficient mitophagy.

Methods

Transforming growth factor-β (TGF-β)-induced or ATG5, ATG7, and PARK2 knockdown-mediated myofibroblast differentiation in LF were used for in vitro models. The anti-fibrotic role of PFD was examined in a bleomycin (BLM)-induced lung fibrosis model using PARK2 knockout (KO) mice.

Results

We found that PFD induced autophagy/mitophagy activation via enhanced PARK2 expression, which was partly involved in the inhibition of myofibroblast differentiation in the presence of TGF-β. PFD inhibited the myofibroblast differentiation induced by PARK2 knockdown by reducing mitochondrial ROS and PDGFR-PI3K-Akt activation. BLM-treated PARK2 KO mice demonstrated augmentation of lung fibrosis and oxidative modifications compared to those of BLM-treated wild type mice, which were efficiently attenuated by PFD.

Conclusions

These results suggest that PFD induces PARK2-mediated mitophagy and also inhibits lung fibrosis development in the setting of insufficient mitophagy, which may at least partly explain the anti-fibrotic mechanisms of PFD for IPF treatment.

Effectiveness of hepatoprotective drugs for anti-tuberculosis drug-induced hepatotoxicity: a retrospective analysis

Background

The effectiveness of hepatoprotective drugs for DIH (drug induced hepatotoxicity) during tuberculosis treatment is not clear. We evaluated the effectiveness of hepatoprotective drugs by comparing the period until the normalization of hepatic enzymes between patients who were prescribed with the hepatoprotective drugs after DIH was occurred and patients who were not prescribed with the hepatoprotective drugs.

Methods

During 2006–2010, 389 patients with active tuberculosis were included in this study. DIH was defined as elevation of peak serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) of more than twice the upper limit of normal (ULN). We divided the patients into the severe (peak serum AST and/or ALT elevation of >5 times the ULN), moderate (peak serum AST and/or ALT elevation of >3 to ≤5 times the ULN), and mild DIH groups (peak serum AST and/or ALT elevation of >2 to ≤3 times the ULN). We compared the average period until the normalization of hepatic enzymes between patient subgroups with and without hepatoprotective drugs (ursodeoxycholic acid: UDCA, stronger neo-minophagen C: SNMC, and glycyrrhizin).

Results

In the severe group, there was no significant difference in the average period until the normalization between subgroups with and without hepatoprotective drugs (21.4 ± 10.8 vs 21.5 ± 11.1 days, P = 0.97). In the mild group, the period was longer in the subgroup with hepatoprotective drugs than that without hepatoprotective drugs (15.7 ± 6.2 vs 12.4 ± 7.9 days, P = 0.046).

Conclusion

Regardless of the severity, hepatoprotective drugs did not shorten the period until the normalization of hepatic enzymes.

Identification of pathogens by comprehensive real-time PCR versus conventional methods in community-acquired pneumonia in Japanese adults

BACKGROUND

Community-acquired pneumonia (CAP) has high morbidity and mortality. Unfortunately, the pathogen detection rate using conventional culture methods is relatively low. We compared comprehensive real-time polymerase chain reaction (real-time PCR) analysis of nasopharyngeal swab specimens (NPS) and sputum samples against conventional methods for ability to detect causative pathogens of CAP.

METHODS

We prospectively enrolled adult CAP patients, including those with prior antibiotic use, from December 2012 to May 2014. For each patient, causative pathogens were investigated conventionally and by real-time PCR that can identify 6 bacterial and 11 viral pathogens.

RESULTS

Patients numbered 92 (mean age, 63 years; 59 male), including 30 (33%) with prior antibiotic use. Considering all patients, identification of causative pathogens by real-time PCR was significantly more frequent than by conventional methods in all patients (72% vs. 57%, p = 0.018). In patients with prior antibiotic use, identification rates also differed significantly (PCR, 77%; conventional, 50%; p = 0.027). Mixed infections were more frequent according to real-time PCR than conventional methods (26% vs. 4%, p < 0.001). By the real-time PCR, Streptococcus pneumoniae was most frequently identified (38%) as a causative pathogen, followed by Haemophilus influenzae (37%) and Mycoplasma pneumoniae (5%). PCR also identified viral pathogens (21%), with sensitivity enhanced by simultaneous examination of both NPS and sputum samples rather than only NPS samples.

CONCLUSIONS

Real-time PCR of NPS and sputum samples could better identify bacterial and viral pathogens in CAP than conventional methods, both overall and in patients with prior antibiotic treatment.

Pathogens in COPD exacerbations identified by comprehensive real-time PCR plus older methods

Respiratory infection is a major cause of exacerbation in chronic obstructive pulmonary disease (COPD). Infectious contributions to exacerbations remain incompletely described. We therefore analyzed respiratory tract samples by comprehensive real-time polymerase chain reaction (PCR) in combination with conventional methods. We evaluated multiple risk factors for prolonged hospitalization to manage COPD exacerbations, including infectious agents. Over 19 months, we prospectively studied 46 patients with 50 COPD exacerbations, collecting nasopharyngeal swab and sputum samples from each. We carried out real-time PCR designed to detect six bacterial species and eleven viruses, together with conventional procedures, including sputum culture. Infectious etiologies of COPD exacerbations were identified in 44 of 50 exacerbations (88%). Infections were viral in 17 of 50 exacerbations (34%). COPD exacerbations caused by Gram-negative bacilli, including enteric and nonfermenting organisms, were significantly associated with prolonged hospitalization for COPD exacerbations. Our results support the use of a combination of real-time PCR and conventional methods for determining both infectious etiologies and risk of extended hospitalization.

The Optimal Cut-off Value of Plasma BNP to Differentiate Heart Failure in the Emergency Department in Japanese Patients with Dyspnea

OBJECTIVE

In the emergency department, it is sometimes difficult to differentiate heart failure (HF) from other diseases (e.g., respiratory diseases) in patients who develop dyspnea. The plasma B-type natriuretic peptide (BNP) levels increase in patients with HF, and various levels are associated with specific New York Heart Association classes. Although the diagnosis of HF should not be made based only on the plasma BNP levels, the identification of a cut-off value for BNP to diagnose HF would be helpful.

METHODS

Patients admitted to the emergency department of our hospital with dyspnea between January 2010 and December 2011 were retrospectively reviewed. The patients whose estimated glomerular filtration rate was less than 30 mL/min/1.73 m(2) were excluded. Patients were divided into two groups: those with HF (n=131) and those without HF (n=138). The cut-off value for BNP was determined by the receiver-operating characteristic curve.

RESULTS

The area under the curve of this curve was 0.934. The optimal cut-off point for detection of HF was 234 pg/mL. The sensitivity and specificity were 87.0% and 85.5%, respectively. The fifth and 95th percentiles of the HF group were 132.2 and 2,420.8 pg/mL, respectively. Those of the non-HF group were 9.7 and 430.2 pg/mL, respectively.

CONCLUSION

Our study suggests that a plasma BNP level cut-off value of 234 pg/mL can be used to detect HF in the emergency department.

Crystal-to-crystal structural transformation of hydrogen-bonding molecular crystals of (imidazolium)(3-hydroxy-2-quinoxalinecarboxylate) through H2O adsorption–desorption

Crystal-to-crystal structural transformation was observed following H₂O adsorption–desorption of hydrogen-bonding molecular crystals.

Progressive diffuse pulmonary interstitial opacities due to complications of pulmonary tumor emboli: an autopsy case report

A 76-year-old man complaining of exertional dyspnea was admitted to our hospital. Chest computed tomography revealed bilateral diffuse ground-glass opacities and small nodules. A transbronchial lung biopsy revealed tumor cell emboli in the pulmonary arteries. The patient was diagnosed with gastric adenocarcinoma using an endoscopic stomach biopsy; however, the interstitial opacities progressively worsened and he died of acute respiratory failure. An autopsy revealed extensive pulmonary tumor embolisms (PTE) with associated ischemic damages, e.g., infarctions, alveolar wall thickening with cuboidal metaplasia, hemorrhage, and diffuse alveolar damage. The ground-glass opacities in the chest computed tomography findings appear to correlate with the pathological ischemic changes associated with PTE.

Autophagy induction by SIRT6 through attenuation of insulin-like growth factor signaling is involved in the regulation of human bronchial epithelial cell senescence

Cigarette smoke (CS)-induced cellular senescence has been implicated in the pathogenesis of chronic obstructive pulmonary disease, and SIRT6, a histone deacetylase, antagonizes this senescence, presumably through the attenuation of insulin-like growth factor (IGF)-Akt signaling. Autophagy controls cellular senescence by eliminating damaged cellular components and is negatively regulated by IGF-Akt signaling through the mammalian target of rapamycin (mTOR). SIRT1, a representative sirtuin family, has been demonstrated to activate autophagy, but a role for SIRT6 in autophagy activation has not been shown. Therefore, we sought to investigate the regulatory role for SIRT6 in autophagy activation during CS-induced cellular senescence. SIRT6 expression levels were modulated by cDNA and small interfering RNA transfection in human bronchial epithelial cells (HBECs). Senescence-associated β-galactosidase staining and Western blotting of p21 were performed to evaluate senescence. We demonstrated that SIRT6 expression levels were decreased in lung homogenates from chronic obstructive pulmonary disease patients, and SIRT6 expression levels correlated significantly with the percentage of forced expiratory volume in 1 s/forced vital capacity. CS extract (CSE) suppressed SIRT6 expression in HBECs. CSE-induced HBEC senescence was inhibited by SIRT6 overexpression, whereas SIRT6 knockdown and mutant SIRT6 (H133Y) without histone deacetylase activity enhanced HBEC senescence. SIRT6 overexpression induced autophagy via attenuation of IGF-Akt-mTOR signaling. Conversely, SIRT6 knockdown and overexpression of a mutant SIRT6 (H133Y) inhibited autophagy. Autophagy inhibition by knockdown of ATG5 and LC3B attenuated the antisenescent effect of SIRT6 overexpression. These results suggest that SIRT6 is involved in CSE-induced HBEC senescence via autophagy regulation, which can be attributed to attenuation of IGF-Akt-mTOR signaling.

Lung adenocarcinoma complicated by Trousseau's syndrome successfully treated by a combination of anticoagulant therapy and chemotherapy

A 63-year-old woman was diagnosed with advanced lung adenocarcinoma complicated by Trousseau's syndrome characterized by non-bacterial thrombotic endocarditis, asymptomatic brain infarction, deep venous thrombosis, and low-grade disseminated intravascular coagulation (DIC). The patient's DIC rapidly became widespread, and multiple micropulmonary embolisms led to severe respiratory failure. She received a blood transfusion and anticoagulant treatment with heparin and recombinant human soluble thrombomodulin, which modestly ameliorated her symptoms, and additional chemotherapy led to tumor shrinkage with concomitant resolution of Trousseau's syndrome. Although there are no established medical approaches for managing Trousseau's syndrome, intensive anticoagulant treatment may be effective for improving the patients' general condition in order for them to be able to undergo subsequent combination chemotherapy.

Mitochondrial fragmentation in cigarette smoke-induced bronchial epithelial cell senescence

Mitochondria are dynamic organelles that continuously change their shape through fission and fusion. Disruption of mitochondrial dynamics is involved in disease pathology through excessive reactive oxygen species (ROS) production. Accelerated cellular senescence resulting from cigarette smoke exposure with excessive ROS production has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Hence, we investigated the involvement of mitochondrial dynamics and ROS production in terms of cigarette smoke extract (CSE)-induced cellular senescence in human bronchial epithelial cells (HBEC). Mitochondrial morphology was examined by electron microscopy and fluorescence microscopy. Senescence-associated β-galactosidase staining and p21 Western blotting of primary HBEC were performed to evaluate cellular senescence. Mitochondrial-specific superoxide production was measured by MitoSOX staining. Mitochondrial fragmentation was induced by knockdown of mitochondrial fusion proteins (OPA1 or Mitofusins) by small-interfering RNA transfection. N-acetylcysteine and Mito-TEMPO were used as antioxidants. Mitochondria in bronchial epithelial cells were prone to be more fragmented in COPD lung tissues. CSE induced mitochondrial fragmentation and mitochondrial ROS production, which were responsible for acceleration of cellular senescence in HBEC. Mitochondrial fragmentation induced by knockdown of fusion proteins also increased mitochondrial ROS production and percentages of senescent cells. HBEC senescence and mitochondria fragmentation in response to CSE treatment were inhibited in the presence of antioxidants. CSE-induced mitochondrial fragmentation is involved in cellular senescence through the mechanism of mitochondrial ROS production. Hence, disruption of mitochondrial dynamics may be a part of the pathogenic sequence of COPD development.

[A case of Legionella pneumophila pneumonia accompanied by acute respiratory distress syndrome and epilepsy]

A 32-year-old female with epilepsy presented at our hospital with high-grade fever, seizures, and unconsciousness. She was initially treated for aspiration pneumonia with ampicillin/sulbactam. Despite antibiotic therapy, her chest X-ray findings dramatically worsened, showing extension to the bilateral lung field. Her PaO2/FiO2 ratio decreased to 70.6. Rapid progression of hypoxia, unconsciousness, and hyponatremia led to the suspicion of Legionella pneumonia; however, it was difficult to make a definitive diagnosis because she had denied using a whirlpool spa and the initial urinary Legionella antigen test results were negative. Therefore, we repeated the Legionella urinary antigen test, which was positive. On the basis of these results, sputum polymerase chain reaction findings, and the four-fold elevation of paired antibodies, the patient was diagnosed as having Legionella pneumonia accompanied by acute respiratory distress syndrome. We considered administering fluoroquinolone antibiotics, that are recommended for severe Legionella pneumonia, although quinolones have a potential risk for causing convulsions. In this case, we carefully administered ciprofloxacin. The patient recovered consciousness after treatment without any relapse of epileptic seizures. We also administered a corticosteroid for severe pneumonia with the expectation of clinical improvement and to avoid intubation. We emphasize the importance of aggressive workup and empirical therapy for patients with Legionella pneumonia with rapidly worsening symptoms and clinical features such as unconsciousness, epilepsy, and hyponatremia and in whom fluoroquinolone and corticosteroid therapy are effective despite the presence of epilepsy.

Medical thoracoscopy performed under local anesthesia is useful for diagnosing pleural metastasis of renal cell carcinoma

A patient with a past history of renal cell carcinoma (RCC) presented to us with an exudative pleural effusion. Because pleural effusion cytology was inconclusive, we performed medical thoracoscopy under local anesthesia. Multiple white tumors measuring approximately 2 cm in diameter were observed on the parietal pleura. Metastatic carcinoma from RCC was diagnosed histologically. Although malignant effusions are rare in cases of RCC metastasis, clinicians should be aware of this possibility. When pleural effusion cytology is inconclusive in a patient with a past history of RCC, medical thoracoscopy can be useful for making the diagnosis of pleural metastasis.

[A case of descending necrotizing mediastinitis caused by infection with Streptococcus agalactiae in a patient with diabetes mellitus]

We report a case with an atypical presentation of descending necrotizing mediastinitis (DNM). A 47-year-old woman with a medical history of untreated type 2 diabetes mellitus and influenza type A virus infection 2 weeks prior to admission was referred to our hospital complaining of right cervical pain and right upper limb swelling. A chest enhanced computed tomographic (CT) scan showed a ring-enhanced mass-like shadow extending from the right sternomastoid muscle down to the right upper mediastinum, compressing the right subclavicular vein. We diagnosed the patient as having DNM based on a physical examination and the CT findings. Because the abscess extended from deep in the neck to the upper mediastinum and right upper pleural space, emergent abscess debridement and drainage was required. After hospitalization, antibiotics (Ampicillin/Sulbactam 12 g/day) were also administered based on Gram-stain findings from the drainage fluid, which showed Gram-positive cocci resembling a string of beads. A culture of the drainage fluid identified Streptococcus agalactiae. Aggressive abscess drainage and early antibiotic therapy resulted in a favorable response. She was discharged without complications on the 33rd hospital day. DNM is well known as a rare but lethal disease. In this case, the presence of diabetes mellitus and post-influenza infection might have been risk factors for a serious S. agalactiae infection. Early aggressive therapy and adequate drainage are recommended for patients with DNM.

Anaplastic meningioma with papillary, rhabdoid, and epithelial features: a case report

A 74-year-old man manifested disturbed consciousness and right hemiparesis. Computed tomography revealed a left frontal parasagittal meningeal tumor with extensive peritumoral brain edema and skull invasion. Subtotal removal was performed. Five years later, he underwent two more operations of massive recurrences. Pathological studies revealed anaplastic meningioma with two different histological areas. One was an epithelial and meningothelial area, and the other was a papillary and rhabdoid area. In the papillary and rhabdoid area, small tumor cells with a high nucleus/cytoplasm ratio proliferated densely around the dilated central capillaries with a pseudopapillary pattern. Many rhabdoid cells (vimentin ++, cytokeratin AE1/AE3 +, epithelial membrane antigen [EMA] + +) tended to be distributed far from the central capillaries. There were many mitotic figures near the central vessels. Dense MIB1-positive nuclei were also observed near the central vessels. The trabecular pattern of the tumor cells in the epithelial area was quite different from the histological features of chordoid meningioma.

Neurally mediated syncope associated with small cell lung cancer: a case report and review

We encountered a case of limited-disease small cell lung cancer with episodic syncope. The frequency of the syncopal attacks increased with the increase in the tumor size, thus a relationship was suspected to exist between the SCLC and syncope. Syncope was evaluated by history taking, 24-hour ECG monitoring, and coronary angiography. As orthostatic hypotension and cardiac disease could be excluded, we finally diagnosed this case as neurally mediated syncope. Serum tests for anti-Hu and anti-Yo antibodies were negative. A temporary pacemaker was inserted for sick sinus syndrome. This patient showed good response to the chemotherapy. No further syncopal attacks were observed after the second course of chemotherapy. Here, in addition we review four cases of SCLC with episodic syncope. Interestingly, in all cases, the tumor was located in the left hilum in close vicinity of the afferent vagal nerve (C-fibers) and mechano-receptor. Therefore, we thought that the mechanism underlying the syncope was mechano-receptor hypersensitivity.

The effects of repetitive compression on nerve conduction and blood flow in the rabbit sciatic nerve

The objective of this study was to clarify the effect of repetitive compression on nerve physiology in an experimental rabbit model. We defined 80 mmHg as a compression force which caused temporary disturbance of nerve conduction and blood flow with a brief compression. The following compressions were applied for 30 minutes to rabbit sciatic nerves: continuous compression, low frequency release compression (1 second of release time every 30 seconds) and high frequency release compression (1 second of release time every 10 seconds). Compound nerve action potentials and nerve blood flow were evaluated from the start of compression until 30 minutes after release. Endoneurial microvascular permeability was evaluated with Evans Blue albumin. The repetitive compression groups showed delay in recovery of compound nerve action potentials and blood flow after release, with endoneurial oedema. These findings suggest that repetitive compression may increase the risk of breakdown of the blood nerve barrier.

[Severe complications and their outcomes in 65 patients with Legionella pneumonia]

The aim of the current study was to investigate the lethal complications of Legionella pneumonia. Severe complications and their outcomes in 65 patients with Legionella pneumonia were studied. All patients who eventually had a fatal outcome or who had severe complications received antimicrobial agents active against Legionella on the admission day. Many patients in the severe complication category had multiple severe complications. Six deaths occurred (mortality rate 9.2%), 4 of which were due to septic shock/multiple organ dysfunction syndrome (MODS) (2 patients) or interstitial pneumonia/pulmonary fibrosis after Legionella pneumonia (2 patients), whereas the other 2 deaths were due to causes unrelated to Legionella pneumonia. Mortality rates for each severe complication were as follows: acute respiratory distress syndrome 27.3% (3 of 11); renal failure 33.3% (2 of 6); disseminated intravascular coagulation 33.3% (2 of 6); severe sepsis 0% (0 of 1); septic shock/MODS 66.7% (2 of 3); interstitial pneumonia/pulmonary fibrosis 50% (2 of 4). Despite prompt diagnosis and appropriate treatment with antimicrobial agents active against Legionella, the lethal complications of Legionella pneumonia are septic shock/MODS and interstitial pneumonia/pulmonary fibrosis.

[Mucoid impaction of the bronchi caused by Schizophyllum commune which developed after discontinuation of itraconazole administration]

We report the case of a 75-year-old woman with mucoid impaction of the bronchi (MIB) due to Schizophyllum commune who improved with itraconazole (ITCZ) administration and relapsed after discontinuation of the drug. She improved again after readministration of ITCZ, and MIB has not recurred. This patient was not suffering from asthma and has been well without steroid administration. Reports of respiratory disorders due to S. commune have been increasing, and cases of allergic bronchopulmonary mycosis (ABPM), fungus ball, lung abscess, and pneumonia have been reported. Including this report, 12 cases of ABPM and MIB due to S. commune have been reported by Japanese authors. Treatment in these 12 cases included anti-fungal agent in 6, single steroid therapy in 3, combination therapy in 2, and bronchial toilet in 1 case. S. commune is not well recognized; however, one should suspect this fungus to be the causative pathogen when Aspergillus species are not detected or anti-Aspergillus antibody is negative.

[Primary ciliary dyskinesia. A case report and comparison with 4 previous cases]

We encountered a 59-year-old man, whose chief complaints were sputum and dyspnea on effort. He had suffered from sinusitis since childhood, and chest computed tomography showed bronchiectasis. Electron microscopic examination of bronchial mucosa biopsied by bronchoscopy showed defect of the inner dynein arm in most of his cilia. We diagnosed primary ciliary dyskinesia. Seminal analysis showed no abnormalities, and the etiology of infertility remains unclear. The present case is the fifth case treated at our hospital. In this paper, we compared this case with 4 cases (2 cases of Kartagener's syndrome and 2 cases of primary ciliary dyskinesia without situs invertus) of our hospital, and findings of previous reports. Primary ciliary dyskinesia should be included in the differential diagnosis even in cases of mild bronchiectasis or normal mobility of sperm. Primary ciliary dyskinesia has more variety in radiological and clinical findings than has been recognized.

[Nemaline myopathy detected with respiratory failure and right ventricular heart failure]

We describe the case of a 40-year-old woman who was admitted for dyspnea and pitting edema of the lower extremities. Severe type II respiratory failure and right ventricular heart failure were present. Non-invasive positive pressure ventilation (NIPPV) improved the symptoms and blood gas values. Since the results of respiratory function tests and computed tomography indicated neuromuscular disease, muscle biopsy was performed and nemaline myopathy was diagnosed. NIPPV was necessary due to severe hypoxia and hypercapnia caused by severe hypoventilation during sleep; however, daytime NIPPV was stopped within a few days, and the patient was discharged with instructions to continue NIPPV at night only. Since discharge, she has been followed-up on an outpatient basis for 8 years. Adult-onset nemaline myopathy with respiratory failure and right ventricular heart failure as presenting features is rare, and NIPPV can be useful in such cases.

Ehlers-Danlos syndrome with recurrent spontaneous pneumothoraces and cavitary lesion on chest X-ray as the initial complications

A 17-year-old-man developed left-sided pneumothorax in 1995. Chest computed tomography (CT) showed a thick-walled cavity in the left lower lobe. Video-assisted thoracic surgery was performed, and pathologic findings of the resected lung showed a cavity, organizing hematoma, and a fibrous nodule. Fragility of connective tissue was suspected, and biochemical and molecular analysis showed reduction of type III collagen production and point mutation of the COL3A1 gene. The patient was diagnosed as having vascular-type Ehlers-Danlos syndrome (EDS). From 2002, the patient developed hemoptysis and bloody sputum once a year. Chest CT detected several nodules and cavities, which were regarded as hematomas with or without excretion. Several vascular changes including aneurysmal formations have been found since 2002, and an aneurysm of the left ulnar artery was resected. The patient continues to be followed regularly on an outpatient basis. We report a rare case of vascular-type EDS who developed pulmonary symptoms as an initial complication.

Stenting for atherosclerotic stenosis of the intracranial or skull base cerebral arteries. Effectiveness and problems

SUMMARY

Since May 1992, we have performed percutaneous transluminal angioplasty (PTA) or stenting 70 times for 65 lesions in 62 patients with atherosclerotic stenosis of the intracranial or skull base cerebral arteries. Stenting was carried out nine times for nine lesions in nine cases. Stenting was performed on patients with an average age of 62. The patients were eight men and one woman. The stenotic lesions involved the internal carotid artery (petrous portion) in four cases, the internal carotid artery (cavernous portion) in two cases, the internal carotid artery (supraclinoid portion) in one case, the middle cerebral artery (M1) in one case, and the vertebral artery (V4) in one case. The degree of stenosis ranged from 70% to 99%, with a mean of 80%. A stent for coronary arteries was used in all cases. After PTA was carried out in four cases, their initial extension was inadequate, and dissection was performed in five cases after PTA. As for the results of the treatment, subarachnoid haemorrhage occurred in one case due to perforation by the guidewire, and a major deficit was accepted. During the operation, asymptomatic cerebral infarction by distal embolism occurred in one case. Although obstruction of the lesion occurred three months after treatment in one case, symptoms did not appear. Stents used for atherosclerotic stenosis of the intracranial or skull base cerebral arteries still do not have sufficient performance. Although the stenting had problems, such as a prolonged patent, in the present condition, it was effective in terms of recovery from complications due to PTA.

Phase II trial of radiotherapy after hyperbaric oxygenation with chemotherapy for high-grade gliomas

We conducted a phase II trial to evaluate the efficacy and toxicity of radiotherapy immediately after hyperbaric oxygenation (HBO) with chemotherapy in adults with high-grade gliomas. Patients with histologically confirmed high-grade gliomas were administered radiotherapy in daily 2 Gy fractions for 5 consecutive days per week up to a total dose of 60 Gy. Each fraction was administered immediately after HBO with the period of time from completion of decompression to irradiation being less than 15 min. Chemotherapy consisted of procarbazine, nimustine (ACNU) and vincristine and was administered during and after radiotherapy. A total of 41 patients (31 patients with glioblastoma and 10 patients with grade 3 gliomas) were enrolled. All 41 patients were able to complete a total radiotherapy dose of 60 Gy immediately after HBO with one course of concurrent chemotherapy. Of 30 assessable patients, 17 (57%) had an objective response including four CR and 13 PR. The median time to progression and the median survival time in glioblastoma patients were 12.3 months and 17.3 months, respectively. On univariate analysis, histologic grade (P=0.0001) and Karnofsky performance status (P=0.036) had a significant impact on survival, and on multivariate analysis, histologic grade alone was a significant prognostic factor for survival (P=0.001). Although grade 4 leukopenia and grade 4 thrombocytopenia occurred in 10 and 7% of all patients, respectively, these were transient with no patients developing neutropenic fever or intracranial haemorrhage. No serious nonhaematological or late toxicities were seen. These results indicated that radiotherapy delivered immediately after HBO with chemotherapy was safe with virtually no late toxicity in patients with high-grade gliomas. Further studies are required to strictly evaluate the effectiveness of radiotherapy after HBO for these tumours.