Adhesion and bactericidal properties of nanostructured surfaces dependent on bacterial motility

Different nanostructured surfaces have bactericidal properties that arise from the interaction between the bacteria and the nanostructured surface. In this study, we focused on the relationship between bacterial motility and bactericidal properties. The motility of Escherichia coli (E. coli) was tuned by genetic engineering, and four types of E. coli (wild type (WT), lacking flagella, and flagellated with deficient motility or deficient chemotaxis) were used to evaluate the adhesion and bactericidal properties of nanostructured surfaces. Cicada (Cryptotympana facialis) wings and Si nano-pillar array substrates were used as natural and artificial nanostructured surfaces, respectively. Differences in motility and chemotaxis strongly influenced the adhesion behavior and to some extent, the damage to the cell membrane. These results suggest that the bactericidal properties of nanostructured surfaces depend on bacterial motility.

Bactericidal effect derived from nanostructured surface was evaluated in the point of view of the motility of E. coli. The results suggest that the properties strongly depend on bacterial motility.     

Risk factors for de novo hepatitis B during solid cancer treatment

BACKGROUNDReactivation of hepatitis B virus (HBV) during anticancer treatment is a critical issue. When treating patients with solid tumors, it is unclear whether specific cancer types or treatments affect HBV reactivation in hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (HBcAb)-positive patients, so-called de novo hepatitis B patients. The risk of de novo hepatitis B may vary based on different background factors.AIMTo determine the frequency and risk factors for de novo hepatitis B during solid tumor treatment.METHODSThis retrospective cohort study comprised 1040 patients without HBsAgs and with HBcAbs and/or hepatitis B surface antibodies (HBsAbs). The patients were treated for solid cancer from 2008 to 2018 at the National Kyushu Cancer Center and underwent HBV DNA measurements. Patient characteristics and disease and treatment information were investigated. HBV DNA measurements were performed using TaqMan polymerase chain reaction (PCR). To identify the risk factors associated with HBV DNA expression, the age, sex, original disease, pathology, treatment method, presence or absence of hepatitis C virus (HCV), and HBsAb and/or HBcAb titers of all subjects were investigated. In patients with HBV DNA, the time of appearance, presence of HBsAgs and HBsAbs at the time of appearance, and course of the subsequent fluctuations in virus levels were also investigated.RESULTSAmong the 1040 patients, 938 were HBcAb positive, and 102 were HBcAb negative and HBsAb positive. HBV DNA expression was observed before the onset of treatment in nine patients (0.9%) and after treatment in 35 patients (3.7%), all of whom were HBcAb positive. The HBV reactivation group showed significantly higher median HBcAb values [9.00 (8.12-9.89) vs 7.22 (7.02-7.43), P = 0.0001] and significantly lower HBsAb values (14 vs 46, P = 0.0342) than the group without reactivation. Notably, the reactivated group showed a significantly higher proportion of cancers in organs related to digestion and absorption (79.0% vs 58.7%, P = 0.0051). A high HBcAb titer and cancers in organs involved in digestion and absorption were identified as independent factors for HBV reactivation (multivariate analysis, P = 0.0002 and P = 0.0095). The group without HBsAbs tended to have a shorter time to reactivation (day 43 vs day 193), and the frequency of reactivation within 6 mo was significantly higher in this group (P = 0.0459) than in the other group.CONCLUSIONA high HBcAb titer and cancers in organs involved in digestion and absorption are independent factors that contribute to HBV reactivation during solid tumor treatment.     

Detection of auto-antibodies against L-myc oncogene products in sera from lung cancer patients

Auto-antibodies against L-myc oncogene products (L-Myc) in sera from lung cancer patients were examined using bacterially synthesized glutathione S-transferase (GST) L-Myc fusion proteins and Western blot analysis. The detection rate of anti-L-Myc antibodies in sera from lung cancer patients was 10%, while that in sera obtained from normal volunteers was 0%. Five patients with non-small-cell lung cancers (2 adenocarcinomas, 2 squamous-cell carcinomas and 2 large-cell carcinoma) were included in the group with anti-L-Myc antibodies. These auto-antibodies belonged to the IgG class and recognized the carboxy terminus of L-Myc. Circulating L-Myc was not detected in sera from patients with anti-L-Myc antibodies. Differences in age, sex, performance status, histology, stage, smoking history and prior treatment were not significantly different between anti-L-Myc antibody-positive and antibody-negative patients. Anti-nuclear antibodies were detected in 40% of lung cancer patients and 57% of those with anti-L-Myc antibodies. Our data suggest that detection of anti-L-Myc antibodies may be helpful in the diagnosis and evaluation of the host-immune response to L-Myc in a subset of lung cancer patients. © 1996 Wiley-Liss, Inc.     

Expression of cathepsin E in pancreas: A possible tumor marker for pancreas,a preliminary report

Ductal cancers of the pancreas frequently express markers of gastrointestinal epithelial cells. Cathepsin E (CTSE) is a non-secretory, intracellular, but non-lysosomal proteinase found in the highest concentration in the superficial epithelial cells of the stomach. The aims of our study were to examine the expression of CTSE in the pancreas, to establish an assay system of CTSE and to evaluate the diagnostic usefulness of CTSE in the pancreatic juice. Eleven patients with pancreatic ductal adenocarcinoma, 10 with mucin-producing adenoma, 3 with intraductal papillary hyperplasia and 43 with chronic pancreatitis were examined. Surgically resected pancreatic tissues were subjected to immunohistochemistry for CTSE. Pancreatic juice was collected from the patients and subjected to sandwich ELISA and Western analysis for detecting CTSE. Positive staining for CTSE was observed in pancreatic ductal adenocarcinoma by immunohistochemistry. CTSE was also expressed in mucin-producing adenoma, intraductal papillary hyperplasia and mucinous hyperplasia. CTSE in the pancreatic juice was present in 8 of 11 patients with pancreatic ductal adenocarcinoma, 5 of 10 patients with mucin-producing tumor, 1 of 3 patients with intraductal papillary hyperplasia and 4 of 43 patients with chronic pancreatitis. The detection frequency of CTSE in the pancreatic juice was significantly higher in the patients with pancreatic ductal adenocarcinoma than in the patients with chronic pancreatitis. Our findings suggest that the expression of CTSE is associated with the pathogenesis of pancreatic ductal adenocarcinoma, that CTSE in the pancreatic juice seems to be a useful marker for a definitive diagnosis and that CTSE may be expressed at a relatively early stage of multistep carcinogenesis in pancreatic lesions. © 1996 Wiley-Liss, Inc.     

Infection with GB virus C in leprous patients in Japan

The detection of hepatitis C virus (HCV) in blood donors and patients with acute and chronic hepatitis has brought to the fore another virus or viruses which can be transmitted parenterally and induce liver disease. The RNA of a candidate virus designated GB virus C (GBV-C) was determined by the polymerase chain reaction with primers deduced from a helicase-like region in 229 leprous patients in Japan. GBV-C RNA was detected in 12 (5.2%) patients, and HCV RNA in 41 (18%). Three patients were coinfected with GBV-C and HCV. The nine patients infected with GBV-C alone had aminotransferase levels lower than the three patients with the mixed infection or the 38 patients infected with HCV only (P < 0.001). Sequence comparison within 100 base pairs in the helicase-like region suggested that two, three and three patients, respectively, would have been infected with three distinct strains of GBV-C. These results indicate that patients with leprosy are at increased risk for infection not only with HCV, but also with GBV-C, and that the infection with GBV-C alone would not induce hepatic injuries as severe as HCV infection. © 1996 Wiley-Liss, Inc.     

Effect of age,height, and prechallenge respiratory resistance on bronchial hyperresponsiveness in childhood asthma using the forced oscillation technique

To evaluate the effects of age, height and prechallenge respiratory system resistance (Rrs) on bronchial responsiveness to methacholine inhalation (BRm) as measured by the oscillation technique in children with mild asthma, we studied BRm in 92 atopic children aged from 8 to 13 years (mean ± SD, 10.5 ± 1.7 years). Inhalation challenge was performed by administering progressively doubling doses of methacholine, until a twofold increase in Rrs from baseline had been reached. The minimum cumulative dose of methacholine (Dmin) at which Rrs deviated from baseline was identified by the point of deflection of the continuously recorded Rrs tracing. The Dmin represented the amount of methacholine which elicited BRm. By using single-regression analysis, height was negatively correlated with Rrs (p < 0.001). Height was positively and Rrs was negatively correlated with age (p < 0.001 and p < 0.001, respectively). Furthermore, height and age were correlated with Dmin (p < 0.001 and p < 0.001, respectively), but prechallenge Rrs was not correlated with Dmin (p > 0.1). To minimize the effect of height and prechallenge Rrs on BRm, the relationships between Dmin and age was studied in a subgroup with a narrow range of heights (135–155 cm, n = 32), and a narrow range of prechallenge Rrs (5.0–6.9 cmH₂ O/L/s, n = 42); there remained a statistically significant correlation between Dmin and age in the groups with comparable heights (p = 0.026) and Rrs (p = 0.003). These data suggest that the BHR in childhood asthma may be affected by height and age when measured by the oscillation technique. Considering the many advantages of the oscillation method, this technique may be very suitable for measuring BHR in childhood asthma. Pediatr Pulmonol. 1996;22:1–6. © 1996 Wiley-Liss, Inc.     

Differential induction of helper and killer T cells from isolated CD4+CD8+ thymocytes in suspension culture

Thymocytes of T cell receptor transgenic mice with nonselecting and RAG-2^−/− backgrounds were developmentally arrested at the CD4⁺CD8⁺ stage before positive selection. These thymocytes underwent lineage commitment upon transient stimulation with a combination of ionomycin, a calcium ionophore, and phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, in suspension culture. The effective drug doses were limited within narrow ranges and much lower than those which induce proliferation of mature T cells. The doses corresponded to those which inhibit glucocorticoid-induced apoptosis in these thymocytes. CD4 lineage commitment required longer duration, higher intensity of the stimulation, or both, than CD8 lineage commitment. Functional helper T cells (Th1 and Th2) were induced from the CD4 lineage-committed cells upon secondary stimulation with a combination of ionomycin and PMA followed by lymphokine treatment. Cytotoxic T cells were induced from the CD8 lineage-committed cells upon incubation with concanavalin A and irradiated splenic dendritic cells, but not with the combination of ionomycin and PMA. These results indicate that positive selection is mimicked by the pharmacological stimulation in the absence of other cell types, but that final maturation of CD8 T cells may require a different signal.     

Autoantigenic epitopes on dna topoisomerase i

Objective. To elucidate the clinical and immunogenetic associations with reactivity to autoantigenic epitopes on DNA topoisomerase I (topo I) recognized by sera from patients with systemic sclerosis (SSc). Methods. Autoantigenic epitopes on topo I were identified by screening an epitope library constructed from topo I complementary DNA restriction fragments using autoimmune anti–topo I–positive sera as a probe. Epitope reactivities of sera from 43 anti–topo I–positive SSc patients were surveyed by immunoblotting, and associations with clinical symptoms and HLA–DR types were examined. Results. Four different epitope regions were identified on the topo I molecule. Immunoreactivity to the region encompassing amino acid residues 658–700, termed ER4, was found to be associated with diffuse cutaneous SSc, progressive pulmonary interstitial fibrosis, and poor prognosis for 15-year survival. SSc patients with ER4 reactivity frequently displayed the DR2/DRw52 phenotype. Conclusion. Molecular analysis of precise antigenic epitopes on topo I is helpful in classifying clinical subsets of SSc.