Salmonella induce autophagy in melanoma by the downregulation of AKT/mTOR pathway.

Salmonella have been demonstrated to inhibit tumor growth. However, the mechanism of Salmonella-induced tumor cell death is less defined. Autophagy is a cellular process that mediates the degradation of long-lived proteins and unwanted organelles in the cytosol. Tumor cells frequently display lower levels of basal autophagic activity than their normal counterparts and fail to increase autophagic activity in response to stresses. Autophagy is involved in the cell defense elimination of bacteria. The signaling pathways leading to activation of Salmonella-induced autophagy in tumor cells remain to be elucidated. We used autophagy inhibitor (3-Methyladenine) and apoptosis inhibitor (Z-VAD-FMK) to demonstrate that Salmonella may induce cell death via apoptosis and autophagic pathway. Meanwhile, we suggested that Salmonella induce autophagy in a dose- and time-dependent manner. The autophagic markers were increased after tumor cell infected with Salmonella. In addition, the protein express levels of phosph-protein kinase B (P-AKT), phosph-mammalian targets of rapamycin (P-mTOR), phosph-p70 ribosomal s6 kinase (P-p70s6K) in tumor cells were decreased by western analysis after Salmonella infection. In conclusion, our results point out that Salmonella induce the autophagic signaling pathway via downregulation of AKT/mTOR pathway. Herein, our findings that Salmonella in controlling tumor growth may induce autophagic signal pathway.

Life satisfaction, coping, self-esteem and suicide ideation in Chinese adolescents: a school-based study.

PURPOSE: To determine the prevalence and associated risk factors of suicidal ideation (SI) among junior, senior high and college school students. METHODS: A total of 5249 students in Anhui Province of China participated in a self-administered anonymous survey. RESULTS: Females were more likely to report SI than males (32.1% vs. 20.6%). Using binary logistic regression analysis, we found that being female, passive coping, lower family satisfaction, lower school satisfaction, lower living environment satisfaction and higher self-esteem were associated with an increased risk of SI. CONCLUSIONS: This study suggested that SI was common among Chinese adolescents. Being female, high score of passive coping, lower family satisfaction, lower school satisfaction, lower living environment satisfaction and higher self-esteem were significantly associated with an increased risk of SI. There is an urgent need to take effective measures reducing the rate of SI among adolescents through collaboration among families, schools and society.

Problem behaviours of middle school students in eastern China and its associated factors.

OBJECTIVE: To investigate the problem behaviours of middle school students and its associated factors in Anhui province of China, and to provide a theoretical basis for promoting early health education. METHODS: A cross-sectional survey was conducted and 4235 middle school students were measured by Prediction Test of Problem Children, Family Environment Scale - Chinese Version, Simple Coping Style Questionnaire, Psychological Sense of School Membership and general state questionnaire. RESULTS: The prevalence of problem behaviours in our sample was 4.5%. Using binary logistic regression analysis, we found that family environment, school belonging, coping style, relationship with mother and classmate relationship were associated with problem behaviours of middle school students. CONCLUSIONS: Poor family environment, poor sense of school belonging, passive acting style were significantly correlated with problem behaviours. There is an urgent need to improve problem behaviours through collaboration among families, schools and society.

Disruption of Type-I IFN pathway ameliorates preservation damage in mouse orthotopic liver transplantation via HO-1 dependent mechanism.

Ischemia/reperfusion injury (IRI) remains unresolved problem in clinical organ transplantation. We analyzed the role of Type-I interferon (IFN) pathway in a clinically relevant murine model of extended hepatic cold preservation followed by orthotopic liver transplantation (OLT). Livers from Type-I IFN receptor (IFNAR) knockout (KO) or wild-type (WT) mice (C57/BL6) were harvested, preserved at 4°C in UW solution for 20 h and transplanted to groups of syngeneic IFNAR KO or WT recipients. Liver graft but not recipient IFNAR deficiency was required to consistently ameliorate IRI in OLTs. Indeed, disruption of Type-I IFN signaling decreased serum alanine aminotransferase (sALT) levels (p < 0.001), diminished Suzuki's score of histological OLT damage (p < 0.01) and improved 14-day survival (from 42%[5/12] in WT to 92%[11/12] in IFNAR KO; p < 0.05). Unlike in WT group, IFNAR deficiency attenuated OLT expression of TNF-α, IL-1ß, IL-6, MCP-1, CXCL-10, ICAM-1; diminished infiltration by macrophages/PMNs; and enhanced expression of antioxidant HO-1/Nrf2. The frequency of TUNEL+ apoptotic cells and caspase-3 activity/expression selectively decreased in IFNAR KO group. Small interfering (si)RNA-directed targeting of HO-1 restored cardinal features of liver IRI in otherwise resistant IFNAR-deficient OLTs. Thus, intact Type-I IFN signaling is required for hepatic IRI, whereas HO-1 is needed for cytoprotection against innate immunity-dominated organ preservation damage in IFNAR-deficient liver transplants.

Investigation of microbiologically influenced corrosion inhibition of 304 stainless steel by D-cysteine in the presence of Pseudomonas aeruginosa.

The influence of D-cysteine (D-cys) on the microbiologically influenced corrosion (MIC) of 304 stainless steel caused by Pseudomonas aeruginosa was investigated in this work. Immersion tests in the sterile and P. aeruginosa-inoculated culture media with different D-cys concentrations were carried out. The results showed that the addition of D-cys inhibited the formation of P. aeruginosa biofilms on stainless steel surfaces. D-cys itself did not affect the corrosion of stainless steel but could decrease the corrosion rate of MIC of stainless steel caused by P. aeruginosa. X-ray photoelectron spectroscopy (XPS) analysis and scanning electrochemical microscopy (SECM) analysis indicated that the biofilm inhibition effect of D-cys greatly reduced the destructive effect of the adhered P. aeruginosa cells on the passive film of the stainless steel, thus inhibiting the MIC of the stainless steel.

Suppression of p38 mitogen-activated protein kinase inhibits hepatitis B virus replication in human hepatoma cell: the antiviral role of nitric oxide.

The role of the p38 mitogen-activated protein kinase (MAPK) pathway in hepatitis B virus (HBV) replication was investigated in this study. After transient transfection with HBV plasmid, p38 MAPK, but not JNK or ERK1/2, was significantly phosphorylated in human hepatoma cell Huh7. Interestingly, HBV proteins and RNA synthesis were significantly inhibited by a specific inhibitor of p38 MAPK, SB203580, in a dose-dependent manner. Intracellular core-associated DNA, extracellular virion-associated DNA and covalently closed circular DNA were also significantly inhibited by SB203580. Further results showed the antiviral role of nitric oxide (NO) on the suppression of HBV replication and downregulation of p38 MAPK phosphorylation. In conclusion, these results suggested that suppression of phosphorylation of p38 MAPK by inhibitor or NO could inhibit intracellular HBV replication.

Histogenesis of symmetrical 1,2-dimethylhydrazine-induced neoplasms of the colon in the mouse.

CF-1 female adult mice were given weekly sc injections of 20 mg symmetrical 1,2-dimethylhydrazine (DMH)-2HCl/kg body weight and killed at various intervals after commencement of the injection. [3H]thymidine (TdR) was given before the animals were killed. The histogenesis of colon neoplasms was investigated by means of autoradiographs prepared from sections of Epon-embedded descending colon, which were stained with periodic acid-Schiff reaction and iron hematoxylin. By 9 weeks after initiation of DMH treatment, the distal 5 cm of the colon became enlarged, the mucosa thickened, and the crypts were elongated and hyperplastic. In the hyperplastic crypts, the number of proliferating cells increased, but the distribution of these cells followed a previously discussed slow cut-off model of Cairnie et al. as for the normal crypts. Differentiation and transformation of epithelial cells occurred, but somewhat aberrantly. Hyperplasia of the crypts occurred diffusely, but neoplastic lesions that began to appear by 9 weeks after the intiial treatment were isolated. An isolated crypt from which a neoplasm developed was first repopulated by what appeared to be altered, undifferentiated "stem" cells. These cells did not differentiate, continued to divide, and eventually upon migration accumulated in the upper part of the crypts, where an earliest identifiable neoplastic lesion was observed. Once such a lesion was formed, it expanded in various directions, depending on the local environments, and formed a polypoid or discoid lesion. The biologic behavior of the neoplasm seemed to be determined by the downward progression of its leading edge. When it penetrated the muscularis mucosae, the neoplasm became highly invasive. In the murine model, the invasive adenocarcinomas were observed by 26 weeks after commencement of DMH treatment.

Inhibition of DNA synthesis by 1,2-dimethylhydrazine and methylazoxymethanol acetate in rabbit colon mucosa in organ culture.

When maintained in organ culture, colon mucosa from male New Zealand White rabbits showed a near-normal mucosal morphology and linear incorporation of [3H]thymidine into mucosal DNA up to 36 hours of incubation. Explants from the descending colon had a higher DNA synthetic activity than did other segments of the large bowel. Inhibition of DNA synthesis in colon explants by 1,2-dimethylhydrazine (DMH) and methylazoxymethanol (MAM) acetate was dose-dependent. When DNA synthesis was determined after an 18-hour incubation, MAM acetate inhibited DNA synthesis at concentrations of 50, 100, 150, and 200 microgram/ml. With the same concentration of DMH, little or no inhibition was observed. At the concentration of 200 microgram/ml, both carcinogens significantly inhibited DNA synthesis after 3 and 6 hours of incubation. With longer incubation, the inhibitory effect of DMH appeared to be reversible, whereas DNA synthesis was continuously inhibited by MAM acetate up to 18 hours of incubation. No altered uptake of [3H]thymidine by colon explants incubated in the presence of DMH or MAM acetate for 18 hours was observed. No morphologic changes were seen in colon explants treated with 200 microgram MAM acetate/ml for 18 hours. Physostigmine sulfate had no influence on MAM acetate-induced inhibition of DNA synthesis in colon explants. These in vitro observations reflected a direct action of DMH and MAM acetate on the colon mucosa and supported the possibilility that colon epithelial cells contain enzymes capable of activating DMH and MAM acetate to their alkylating carcinogens.

Interleukin-1 inhibits cholesterol side-chain cleavage cytochrome P450 expression in primary cultures of Leydig cells.

Interleukin-1 (IL-1) is a potent inhibitor of Leydig cell function. We have reported that IL-1 inhibited hCG-induced cAMP and testosterone formation. In the present study we evaluated the effect of IL-1 on Leydig cell cholesterol side-chain cleavage cytochrome P450 (P450scc) mRNA levels. P450scc is the rate-limiting enzyme for Leydig cell steroidogenesis. Highly purified Leydig cells were prepared from adult Sprague-Dawley male rats (55-65 day-old) using the combination of elutriation and Percoll gradient. Purified Leydig cells were then cultured with or without IL-1 beta (1-100 ng/ml) and recombinant human monocyte-derived IL-1 receptor antagonist (250 ng/ml) for 24 h. hCG (10 ng/ml), 8-bromo-cAMP (0.1 mM), or 4 beta-phorbol 12 beta-myristate 13 alpha-acetate was then added, and cultures were continued for an additional 6 h. P450scc mRNA levels of Leydig cells were very low to undetectable after 24 h in culture and could be stimulated by the addition of either hCG (10 ng/ml) or 8-bromo-cAMP (0.1 mM), but the addition of 4 beta-phorbol 12 beta-myristate 13 alpha-acetate had no effect. P450scc mRNA levels increased as early as 2 h after the addition of hCG. Furthermore, cycloheximide (1 microgram/ml) markedly blocked hCG-induced P450scc mRNA expression. This indicates that synthesis of a labile new protein(s) is required for the induction of P450scc mRNA by hCG. IL-1 beta inhibited hCG-stimulated testosterone formation and P450scc mRNA expression in a dose-dependent manner. The inhibitory effects of IL-1 beta could be reversed by the concomitant addition of IL-1 receptor antagonist. Our results suggest that P450scc mRNA levels of Leydig cells are modulated by IL-1. This may be one mechanism that could explain the inhibitory effects of IL-1 on Leydig cell steroidogenesis.

Human chorionic gonadotropin up-regulates insulin-like growth factor-I receptor gene expression of Leydig cells.

The effects of hCG, 8-bromo-cAMP, 4 beta-phorbol 12 beta-myristate 13 alpha-acetate, and forskolin on insulin-like growth factor-I (IGF-I) receptor gene expression of Leydig cells were studied. The treatment of purified Leydig cells with hCG caused a dose-dependent increase in [125I]IGF-I binding to Leydig cells without changes in binding affinity, indicating that the increased binding was due to increased receptor numbers and not to increased affinity. The minimal time required for hCG to induce IGF-I binding was 6 h, and it had reached a plateau at 16 h. 8-Bromo-cAMP (1 mM) increased IGF-I binding about 2-fold, and forskolin (10 microM) increased binding about 51%. Using the ribonuclease protection assay, we found that hCG and 8-bromo-cAMP could increase IGF-I receptor mRNA expression as early as 2 h before the increase in IGF-I binding. The induction by hCG was over 3.5-fold at 4 h and decreased to about 2-fold at 6 h. 4 beta-Phorbol 12 beta-myristate 13 alpha-acetate had a very small effect on IGF-I receptor mRNA levels (1.5-fold increase at 2 h and no changes at 4 and 6 h). In conclusion, IGF-I receptors can be up-regulated by hCG, 8-bromo-cAMP, and forskolin. The up-regulation of IGF-I receptor number is associated with transient increases in IGF-I receptor mRNA levels. This could be a mechanism by which hCG and IGF-I interact to enhance Leydig cell steroidogenesis.

Interleukin-1 beta induces interleukin-1 alpha messenger ribonucleic acid expression in primary cultures of Leydig cells.

Previously, we have reported that interleukin-1 (IL-1) can modulate Leydig cell steroidogenesis. Recently, IL-1-like material has been shown to be present in the testis; however, the cellular source of this material remains unclear. In the present study we found that human recombinant IL-1 beta (1-100 ng/ml) caused dose-dependent increases in IL-1 alpha mRNA expression in Leydig cells. Similar to that reported in other tissues, IL-1 alpha mRNA from Leydig cells is mainly 2.2 kilobases. IL-1 alpha mRNA expression in Leydig cells was detectable as early as 2 h after the addition of IL-1 beta (10 ng/ml) and persisted for up to 24 h. Lipopolysaccharide also stimulated IL-1 alpha mRNA expression in these cells, but phorbol ester had no effect. Our results indicate that Leydig cells are a potential source of IL-1, which has both autocrine and paracrine effects.

Sarcoidosis after renal transplantation.

This is the case of a 41-year-old renal transplant recipient taking tacrolimus immunosuppressive therapy, who had a large pleural effusion, found on a chest radiograph during the work-up of digital clubbing. The patient had undergone a renal transplant 17 months earlier for end-stage renal disease secondary to immunoglobulin A nephropathy. Analysis of the effusion fluid demonstrated a lymphocytic exudate. Biopsy specimens of pleural and lung tissues showed noncaseating granulomas. Fluid and tissue cultures were negative for viral, fungal, and bacterial pathogens. Diagnosis of sarcoidosis was established by identification of noncaseating granulomas in pleural and lung tissue, the exclusion of other conditions, and rapid resolution of the effusion after the institution of corticosteroid therapy. The patient has remained free of pulmonary symptoms and had normal chest radiographs during the 20-month follow-up period.

Cytomegalovirus transmission in special-care centers for mentally retarded children.

This study aimed to determine whether special-care centers for mentally retarded children are high-risk settings for cytomegalovirus (CMV) transmission. Serum and urine specimens obtained from 311 mentally retarded children aged 3 to 12 in three centers were compared for CMV seropositivity and CMV viruria with specimens from 360 normal children of the same ages. A seropositivity rate of 73.5% and a viruria rate of 8.7% were found among the children attending special-care centers. These rates were significantly higher than the 59.2% seropositivity and 1.7% viruria found among normal children. By logistic regression analysis, it was shown that the prevalence of CMV viruria in the class/center was one of the most important determinants for acquiring CMV infection. The data suggest that acquisition of CMV from playmates or classmates occurs frequently in special-care centers and that horizontal transmission of virus is the most plausible explanation for the higher prevalence of CMV infection among mentally retarded children.

Degenerative behavior of epithelial cells in the colonic crypt of the mouse following administration of colonic carcinogen, 1,2-dimethylhydrazine.

The degenerative behavior of cells following administration of 1,2-dimethylhydrazine was analyzed in its target organ, the distal colon of the mouse. Within 3-6 h after carcinogen treatment, an increasing number of epithelial cells in the proliferative compartment of the crypt degenerated. Degenerating cells were present most frequently as phagosomes in the neighboring epithelial cells, and infrequently as pyknotic nuclei being extruded from the epithelial lining in the crypt. Epithelial cells prelabeled with [3H]thymidine degenerated first, followed by those not prelabeled, indicating that the carcinogen-induced degeneration of cells occurred after passage of cells through the DNA synthesis phase.

Prospective analysis of liver biopsies before and after methotrexate therapy in rheumatoid patients.

The significance of hepatic changes in methotrexate-treated RA patients is unclear at this time. In our group of RA patients, there was a slight increase in the incidence of triaditis and fat during methotrexate therapy. Disease duration greater than or equal to 10 years was associated with increased hepatic triaditis before treatment. Age greater than 50 years was associated with increased hepatic fat before and after treatment. It appears that patients' ages and duration of underlying RA account for some changes, independent of methotrexate therapy. Several of our patients changed from higher to lower histologic grade or had an apparent decrease in fibrosis, fat, or triaditis on the pathologists' reports and the blind readings of the repeat biopsies. This may be explained by sampling error. More importantly, some of these changes may not be of clinical significance. One report of methotrexate-induced cirrhosis in patients with psoriasis demonstrated that in all but one of 14 patients who continued receiving methotrexate the cirrhosis decrease or did not progress. This may also be true of the hepatic fibrosis seen in RA after methotrexate treatment. In this study, there did not appear to be changes seen on pretreatment liver biopsy that were predictive of subsequent fibrosis or cirrhosis. Our data indicate that pretreatment biopsy is unwarranted in a population similar to ours. However, our practice has been to try to avoid methotrexate in patients with diabetes, prior liver disease, alcoholism, or obesity because of previous reports suggesting that these patients are at increased risk for the development of cirrhosis. Only the above-mentioned patient, eventually diagnosed as having cirrhosis, might have been handled differently. Including the study, none of the approximately 700 RA patients in the literature having liver biopsies after methotrexate therapy have developed cirrhosis consequent to its use. Most of these had received a total dose of approximately 1,500 mg in small weekly doses, and alcohol was prohibited. Below this cumulative dose the risk of clinically significant liver damage in carefully selected patients is very low. In view of this experience, the recommendation that RA patients have liver biopsies after 1,500 mg of methotrexate (a holdover from the psoriasis literature) may be too conservative in low-risk RA patients, provided methotrexate is administered weekly and alcohol is prohibited. Recognizing that the absolute need for biopsy is unproven, a more realistic milestone for those choosing biopsy might be after each 2,000 to 2,500 mg.(ABSTRACT TRUNCATED AT 400 WORDS)

Gastric schwannoma found incidentally 19 years after a horizontal gastroplasty for morbid obesity.

This report represents the first known case of a gastric schwannoma in a patient subsequent to a gastric stapling and partitioning procedure for morbid obesity. The submucosal tumor found in the collapsed distal portion of the stomach was merely an incidental finding and it appeared that all of the patient's ongoing symptomatology (nausea and vomiting after meals) was a reflection of the chronic obstruction that was present at the gastric partitioning staple-line. No correlation between gastric stapling and partitioning and the development of gastric schwannoma is known or is suggested in this report.

Development of hematogenous pneumococcal meningitis in adult mice: the role of TNF-alpha.

Bacterial penetration across the blood-brain barrier (BBB) into the central nervous system is the first step in development of meningitis. The role of tumor necrosis factor-alpha (TNF-alpha) in the penetration process was examined with peripheral infection of Streptococcus pneumoniae type 6. After intraperitoneal infection of S. pneumoniae type 6, the BBB opening was increased continuously from 6 h and the mice died of septic shock within 36 h due to bacterial overgrowth. The bacteria crossed the BBB and began to deposit in brain at 6 h post infection. There was strong staining of TNF-alpha on blood vessels of brain from 6 h to 24 h post infection. Anti-TNF-alpha antibody blocked both the BBB opening and the entrance of circulatory S. pneumoniae type 6 into brain, indicating that TNF-alpha played an important role in controlling the opening of BBB. Furthermore, an adult murine model of hematogenous pneumococcal meningitis was developed that is based on opening of the BBB by TNF-alpha and controlling the degree of bacteremia by cefazolin antibiotic. In conclusion, hematogenous meningitis developed as TNF-alpha initiated BBB opening, peripheral bacteria entered into the brain and formed bacterial emboli, and then progressed to meningitis.

Histogenesis of tubular adenomas in hereditary colonic adenomatous polyposis.

Tubular adenomas were studied morphometrically and histopathologically in colectomy specimens from seven children and five young adults with hereditary colonic adenomatous polyposis. In each age group and in each patient, the diameter and height of adenomas showed a log normal distribution. Both variables differed significantly among patients in each age group and also between the two age groups. In the young adults, there was a selective growth of certain adenomas. Scatter diagrams of the diameter vs height of adenomas showed that adenomas grew preferentially in the horizontal plane in early development, giving adenomas a discoid shape. Adenomas greater than 8 mm in diameter grew both horizontally and vertically. The horizontal growth was due to division of adenomatous crypts, and adenomas greater than 8 mm in diameter also exhibited elongation of crypts.

Solitary intestinal fibromatosis: a rare cause of intestinal obstruction in neonate and infant.

A 5-month-old white boy infant exhibited remarkable growth retardation and subsequently developed ileal obstruction, which was found to be due to solitary intestinal fibromatosis. This rare lesion has an excellent prognosis if it is completely excised. This is in contrast to cases of congenital fibromatosis with multiple lesions, which carries a poor prognosis.