FAT1 acts as an upstream regulator of oncogenic and inflammatory pathways, via PDCD4, in glioma cells.

Glioblastoma multiforme (GBM) is the most aggressive and the commonest primary brain tumor with a tendency for local invasiveness. The pathways of neoplasia, invasion and inflammation are inextricably linked in cancer and aberrations in several regulatory pathways for these processes have been identified. Here we have studied the FAT1 (Homo sapiens FAT tumor-suppressor homolog 1 (Drosophila)) gene to identify its role in the tumorigenecity of the gliomas. The expression of FAT1 was found to be high in grade IV glioma cell lines (U87MG, A172, U373MG and T98G) but low in grade III glioma cell lines (GOS3 and SW1088). Two cell lines (U87MG and A172) with high FAT1 expression were chosen for in vitro FAT1-knockdown studies. FAT1 knockdown by small interfering RNA resulted in decreased migration and invasion of both the cell lines along with increased expression of the tumor-suppressor gene programmed cell death 4 (PDCD4). Increased PDCD4 expression led to the attenuation of activator protein-1 (AP- 1) transcription by inhibiting c-Jun phosphorylation and resulted in concomitant decrease in the expression of AP-1-target genes like MMP3, VEGF-C and PLAU, the pro-inflammatory regulator COX-2 and cytokines IL1b and IL-6. Conversely, simultaneous silencing of PDCD4 and FAT1 in these cells significantly enhanced AP-1 activity and expression of its target genes, resulting in increase in mediators of inflammation and in enhanced migratory and invasive properties of the cells. We also observed a negative correlation between the expression of FAT1 and PDCD4 (P = 0.0145), a positive correlation between the expression of FAT1 and COX-2 (P = 0.048) and a similar positive trend between FAT1 and IL-6 expression in 35 primary human GBM samples studied. Taken together, this study identifies a novel signaling mechanism mediated by FAT1 in regulating the activity of PDCD4 and thereby the key transcription factor AP-1, which then affects known mediators of neoplasia and inflammation.

TIGAR induces p53-mediated cell-cycle arrest by regulation of RB-E2F1 complex.

BACKGROUND: p53 induces cell-cycle arrest and apoptosis in cancer cells and negatively regulates glycolysis via TIGAR. Glycolysis is crucial for cancer progression although TIGAR provides protection from reactive oxygen species and apoptosis. The relation between TIGAR-mediated inhibition of glycolysis and p53 tumour-suppressor activity is unknown. METHODS: RT-PCR, western blot, luciferase and chromatin immunoprecipitation assays were used to study TIGAR gene regulation. Co-IPP was used to determine the role of TIGAR protein in regulating the protein-protein interaction between retinoblastoma (RB) and E2F1. MCF-7 tumour xenografts were utilised to study the role of TIGAR in tumour regression. RESULTS: Our study shows that TIGAR promotes p21-independent, p53-mediated G1-phase arrest in cancer cells. p53 activates the TIGAR promoter only in cells exposed to repairable doses of stress. TIGAR regulates the expression of genes involved in cell-cycle progression; suppresses synthesis of CDK-2, CDK-4, CDK-6, Cyclin D, Cyclin E and promotes de-phosphorylation of RB protein. RB de-phosphorylation stabilises the complex between RB and E2F1 thus inhibiting the entry of cell cycle from G1 phase to S phase. CONCLUSION: TIGAR mediates de-phosphorylation of RB and stabilisation of RB-E2F1 complex thus delaying the entry of cells in S phase of the cell cycle. Thus, TIGAR inhibits proliferation of cancer cells and increases drug-mediated tumour regression by promoting p53-mediated cell-cycle arrest.

Re-oxygenation causes hypoxic tumor regression through restoration of p53 wild-type conformation and post-translational modifications.

Hypoxic tumors are resistant to conventional therapies through indirect mechanisms such as the selection of resistant phenotype under chronic hypoxia. Hyperbaric oxygen (HBO) therapy has been shown to increase oxygen level and induce apoptosis in hypoxic tumor. However, it could produce significant adverse effects including oxygen toxic seizures and severe radiation tissue injury due to high pressure. We have shown that repeated oxygenation at 30% O(2) (1 atmospheres absolute) results in significant regression of MCF-7 tumor xenografts without any adverse effect. In MCF-7 cells, re-oxygenation showed an eightfold increase in cellular apoptosis. Both in hypoxic tumor and in hypoxic cells, that exclusively favor p53 to exist in mutant conformation, re-oxygenation restores p53 wild-type conformation. The oxygen-mediated rescue of mutant p53 followed by its trans-activation is responsible for the induction of p53-downstream apoptotic, cell-cycle arrest and DNA-repair genes. Further, p53 trans-activation may thus be due to its post-translational modifications as a result of re-oxygenation. We have thus concluded that oxygen therapy without pressure, as opposed to HBO therapy, may be ideal for hypoxic tumor regression, which functions through oxygen-mediated rescue of mutant p53 followed by induction of apoptosis.

Modification of P450 activity and its effect on 1,2-dichlorobenzene toxicity in Fischer 344 rats.

This study examined the contribution of biotransformation by the mixed function oxidase system on hepatic and renal toxicity of 1,2-dichlorobenzene (1,2-DCB). Male Fischer 344 (F344) rats (190-250 g) were pretreated with phenobarbital (PB), beta-naphthoflavone (BNF), pyridine (PYR), piperonyl butoxide (PiBx) or vehicle prior to the administration of 2 or 3 mmol/kg of 1,2-DCB. Pair-fed control animals were treated with corn oil, (1 ml/kg). Plasma alanine amino-transaminase (ALT/GPT) was increased in a dose-dependent manner by 1,2-DCB. Pretreatment with PB, BNF or PB pretreatment prior to 1,2-DCB administration increased hepatic toxicity within 24 h. Toxicity was characterized by increased ALT/GPT activity and increased liver weight. Acute administration of 1,2-DCB produced renal alterations within 24 h. Renal toxicity was characterized by altered blood urea nitrogen (BUN) concentration and decreased renal cortical slice accumulation of p-aminohippurate (PAH) 24 h after injection of 3 mmol/kg 1,2-DCB. Pretreatment with PB, BNF or PYR increased the renal toxicity of 2 and 3 mmol/kg 1,2-DCB. Conversely, pretreatment with PiBx to inhibit P450 activity slightly decreased the hepatic and renal toxicity of 1,2-DCB. These results establish that the kidney was a target organ for 1,2-DCB toxicity and that the proximal tubule was a site of damage. Additionally, these studies indicate induction of P450 isozymes increased the hepatic and renal toxicity of 1,2-DCB. Further studies are needed to examine the specific role of P450 in generation of toxicity.

Acute hepatic and renal toxicity of dichlorobenzene isomers in Fischer 344 rats.

Studies were conducted to examine acute hepatic and renal toxicity of dichlorobenzene (DCB) structural isomers. Male Fischer 344 (F344) rats were injected with 2, 3 or 4 mmol kg-1 of 1,2-DCB, 1,3-DCB or 1,4-DCB (o-, m-, p-). Pair-fed control (PFC) animals were injected (i.p.) with corn oil (1 ml kg-1). Hepatic and renal toxicity was quantitated 24 h after injection of DCB or vehicle. Plasma transaminase (ALT/GPT) activity was increased (P < 0.05) by 1,2-DCB as a function of dose administered. Centrilobular necrosis was observed in rats treated with 1,2-DCB while morphology was relatively normal in rats treated with m- or p-DCB. Administration of (2 or 4 mmol kg-1) 1,3-DCB or 1,4-DCB did not alter kidney weight or blood urea nitrogen (BUN) levels. Renal cortical slice accumulation of p-aminohippurate (PAH) was decreased (P < 0.05) by (2 and 4 mmol kg-1) 1,3-DCB and (3 and 4 mmol kg-1) 1,2-DCB while accumulation of the cation tetraethylammonium (TEA) was decreased by 4 mmol kg-1 1,4-DCB. (TEA). The results of these studies demonstrated that ortho substitution enhanced hepatic and renal toxicity. The results also would suggest that the liver was more sensitive than the kidney for DCB toxicity.

Acute renal and hepatic toxicity of 2-haloanilines in Fischer 344 rats.

Aniline and its halogenated derivatives are widely used as chemical intermediates. The purpose of this study was to determine the hepatotoxic and nephrotoxic potential of the 2-haloanilines. Male Fischer 344 rats (n > or = 4) were injected (i.p.) with 1.0 or 1.25 mmol/kg of: aniline (A), 2-fluoroaniline (2-FA), 2-chloroaniline (2-ClA), 2-bromoaniline (2-BrA), 2-iodoaniline (2-IA) or vehicle (0.9% saline, 2.5 ml/kg). All compounds were injected as hydrochloride salts. Renal and hepatic function was monitored 24 h after treatment. All of the 2-haloanilines induced oliguria, diminished kidney weight, tubular casts and decreased renal cortical slice accumulation of organic anions. Blood urea nitrogen (BUN) levels were increased (P < 0.05) by treatment with 1.0 or 1.25 mmol/kg of 2-FA, 2-ClA or 2-BrA. Hepatic alterations were also observed and characterized by elevated plasma ALT/GPT activity and altered morphology in the centrilobular region. The nephrotoxic and hepatotoxic potentials were similar among the 2-haloanilines but aniline was less toxic than its 2-halo derivatives. These results demonstrated that halogen substitution at the 2-position of aniline increased hepatic and renal toxicity. However, the severity of toxicity was not influenced by the nature of the halogen substituent.

[The sexuality of adolescents from 14 to 19 in a given population]. / La sexualidad de los adolescentes de 14 a 19 años de una población dada.

A study by a survey about sexuality in adolescents was performed in 218, subjects aged 14-19 years with the aim of knowing the level of sexual intercourse practice, the degree of sexual information and the use of contraceptive methods and history of pregnancy by age and sex. In the analysis made it was found that 51% of the sample have sexual intercourse since early adolescents. The majority has information about contraceptive methods. Only 66% of adolescents who have sexual intercourse is protected against impregnation or infections; 38 have no protection at all. The most effective contraceptive methods for this group such as condom or diaphragm are not known or not used by them. 61% of young people who has sexual intercourse had a history of pregnancy, most of them having given birth to a child in first place, followed by uterine curettage and as a result they left school and a few began to work. The family doctor and the nurse must provide sexual education to the family due to the relation they have with their population.

Catalase negative mutants of Helicobacter pylori.

Nine strains of Helicobacter pylori have been isolated exhibiting spontaneous mutations with a loss of catalase activity. Growth characteristics in vitro were unaffected by the mutation showing that catalase is not essential for growth of Helicobacter pylori. Parent strains and mutants could not be distinguished morphologically from each other when compared by electron microscopy. Restriction endonuclease digestion with HindIII, separated in an 0.7% agarose gel in TBE buffer, showed each pair to be highly related to each other. SDS-PAGE separation of proteins from four mutants and parent strains showed that all mutants lacked a 57 kDa protein. The partial N-terminal sequence of this protein shows homology with maize catalase and may be the subunit of the Helicobacter pylori catalase tetramer. It is concluded that catalase negative mutants of Helicobacter pylori occur spontaneously in vitro, but have not yet been observed in vivo. The paucity of such catalase negative strains in clinical specimens could mean that catalase is a virulence factor in vivo that puts mutants at a selective disadvantage.

Double-blind randomized trial of bismuth subsalicylate and clindamycin for treatment of Helicobacter pylori infection.

We evaluated clindamycin and bismuth subsalicylate (Pepto-Bismol) for treatment of Helicobacter pylori infection. Patients with culture or histology positive for H. pylori were randomized to receive two tablets of bismuth subsalicylate four times daily for 4 weeks or bismuth combined with 2 weeks of 300 mg clindamycin four times daily. Clinical symptoms were recorded before and after treatment by means of visual analog scales. Patients in both treatment arms showed improvement in clinical scores for abdominal pain, heartburn, and gas or bloating. Microbiologic cure was achieved in only 1 of 11 patients treated with bismuth alone and in none of 7 treated with bismuth/clindamycin. Successful eradication of H. pylori may require combination of multiple antibiotics, as recommended at the IXth World Congress of Gastroenterology, or pharmacokinetic modulators such as H2-blockers or omeprazole.

Diagnosis of Helicobacter pylori infection in adult and pediatric patients by using Pyloriset, a rapid latex agglutination test.

Pyloriset (Orion Diagnostica, Espoo, Finland) is a rapid antibody test using latex particles coated with acid-extracted antigen of Helicobacter pylori. We evaluated its ability to predict infection in 100 adult patients and 50 pediatric patients referred for gastric endoscopy. Sixty of 65 H. pylori-infected adults were correctly identified by the test. There were 12 false-positive and 5 false-negative reactions seen. Pyloriset had a sensitivity of 92% and a specificity of 66%. The positive predictive value was 83% and the negative predictive value 82%. In contrast, sensitivity dropped to 36% in the pediatric patients and the positive predictive value was only 40%. Pyloriset could become an important alternative to other more time-consuming diagnostic tests for H. pylori-infected adult patients but is inadequate for diagnosis of pediatric H. pylori infection.

Extramedullary plasmacytoma of the soft palate.

A 59-year-old white male presented with symptoms of an upper respiratory infection and the sensation of nasal fullness or obstruction. There were no constitutional symptoms or history of previous oropharyngeal neoplasms. Examination revealed a fleshy tan-pink 2 cm. x 1 cm. pedunculated lesion at the base of the uvula posteriorly, extending into the posterior soft palate. Indirect laryngoscopy confirmed extension of the lesion base onto the posterior soft palate. There was no palpable cervical adenopathy. CT scan of the sinuses and neck revealed no abnormality except the soft tissue mass in the area of the uvula and soft palate. Excisional biopsy of the lesion revealed a plasmacytoma which produced a monoclonal lambda chain immunoglobulin. Hemoglobin was 17.2 g/d. Serum electrophoresis and immunophoresis, Bence-Jones protein, bone marrow, and bone scan were normal. Twenty-six months later, a 1.5 cm. pedunculated lesion was noted at the site of original tumor, which was demonstrated to be recurrent plasmacytoma on excisional biopsy. No other lesions were identified on direct laryngoscopy and skeletal survey was normal. Repeat laboratory studies were normal except for a slight hypergammaglobulinemia (total protein 6.4 g/d., albumin 51.5 percent, alpha 1 globulin 4.0 percent, alpha 2 globulin 11.4 percent, beta globulin 12.8 percent, and gamma globulin 20.2 percent). The patient refused further treatment and has had no further recurrences at one year.

Egg yolk emulsion agar, a new medium for the cultivation of Helicobacter pylori.

We developed a new agar, egg yolk emulsion (EYE) agar, for cultivation of Helicobacter pylori. EYE agar contains Columbia agar base (Oxoid), 10% EYE (Oxoid), 1% IsoVitaleX (BBL), and 40 mg of Triphenyleteraxolium chloride (Sigma) per liter. We compared EYE agar with the following agars: (i) brain heart infusion agar-7% horse blood-1% IsoVitaleX (GDW agar; C. S. Goodwin, E. D. Blincow, J. R. Warren, T. E. Waters, C. R. Sanderson, and L. Easton, J. Clin. Pathol. 38:1127-1131, 1985), (ii) brain heart infusion agar-10% horse serum-0.2% charcoal-1% yeast extract-40 mg of triphenyltetrazolium chloride per liter (GLU agar; Y. Glupczynski, M. Labbe, and F. Thiabaumont, p. 3-6, in F. Megraud and H. Lamouliatte, ed., Gastroduodenal Pathology and Campylobacter pylori, 1989), (iii) Columbia agar with 7% lysed horse blood (D&M agar; J. C. Dent and C. A. M. McNulty, Eur. J. Clin. Microbiol. Infect. Dis. 7:555-558, 1988), and (iv) brain heart infusion agar-10% EYE-1% IsoVitaleX (BHIE agar). H. pylori CFU counts, expressed as average percentages of maximum growth, were as follows: EYE agar, 96; GDW agar. 76; BHIE agar, 57; D&M agar, 52; and GLU agar, 23. Colony counts for EYE agar were significantly higher than for GDW agar (P = 0.027), BHIE agar (P = 0.005), D&M agar (P = 0.0001), and GLU agar (P less than 0.0001). EYE agar also had higher CFU counts than two commercial chocolate media; the EYE agar count was 80%, versus 33% for BBL chocolate medium and 63% for Remel chocolate medium.

Renal accumulation and urinary excretion of cisplatin in diabetic rats.

Previous work has demonstrated that cisplatin nephrotoxicity was attenuated in streptozotocin (STZ)-induced diabetic rats. The following studies investigated the hypothesis that renal cisplatin accumulation was reduced in diabetic rats. Male Fischer 344 (F344) rats were injected with 32 mg/kg STZ (i.p.) or citrate buffer. Renal platinum (Pt) accumulation was quantitated 0-96 h after the administration of 5 mg/kg cisplatin (i.p.) to normoglycemic and diabetic rats (greater than or equal to 4/group). Total renal Pt accumulation was decreased (P less than 0.05) in the diabetic rats, when compared to the normoglycemic group, 6-48 h after cisplatin injection. Further studies were also conducted to examine if urinary cisplatin excretion was enhanced in diabetic relative to normoglycemic groups. Urinary Pt excretion was quantitated 0-96 h following cisplatin (5 mg/kg, i.p.) administration. Pt excretion was increased in the diabetic group relative to the normoglycemics when comparisons were made on the basis of Pt excreted per hour or cumulative Pt excretion. Differences were also detected in urinary Pt concentration. The diabetic group had a lower urinary concentration of the metal 12-96 h after cisplatin injection. These findings suggest that the reduction in nephrotoxicity in diabetic rats may be at least partially due to decreased renal accumulation as well as altered renal excretion.

Histologic characteristics of Campylobacter pylori (Helicobacter pylori) mediated gastritis.

One hundred-nineteen specimens were reviewed to determine whether or not there were histologic changes specific for Campylobacter pylori (CP), (Helicobacter pylori) mediated gastritis. Hematoxylin and eosin (H&E), Brown-Hopp, and Wright-Giemsa stained sections were examined independently by two pathologists for (a) the presence of acute cryptitis, (b) percent and degree of crypt involvement, and (c) spectrum of inflammatory cells within the lamina propriae. The amount of mucus was quantified on the Periodic Acid Schift (PAS)-Alcian Blue stain sections. Changes in the character of the mucus were noted by using both the PAS-Alcian Blue and the High Iron Diamine-Alcian Blue. A positive specimen for Campylobacter pylori (CP+), (Helicobacter pylori) was defined as one in which curved or spiral shaped microbes were identified on Wright-Giemsa and Brown-Hopp stain. Seventy-eight specimens were CP+ and 41 CP-. Statistically significant histologic findings included the extent and degree of superficial cryptitis and the preponderance of plasma cells in CP+ cases. These findings confirm aspects seen in an animal model and suggest that there is an histologic pattern consistent with C. pylori (Helicobacter pylori) mediated gastritis.

Giant basal cell carcinoma of the back.

Basal cell carcinoma accounts for 65-75 per cent of all skin carcinomas. We describe the case of a basal cell carcinoma of the back that was allowed to grow to a giant size. Even when this size, basal cell carcinomas rarely metastasize.

Wound endotoxin is not a principal mediator of postburn hypermetabolism in rats.

Localized bacterial colonization of a 30% total body surface burn (TBSB) wound raises the resting metabolic rate of rats. To determine whether endotoxin (LPS) released in the burn wound contributes to this response, the metabolic rates and colonic temperatures of male Sprague-Dawley rats were monitored before and for 1 week after thermal injury. Wounds were seeded with non-virulent P. aeruginosa (NVP), or S. epidermidis (SE) or were left unseeded at the time of injury. Non-bacteremic SE-seeded rats were as hypermetabolic as the NVP-seeded animals on postburn days (PBDs) 3-4 and 7-8, indicating that wound LPS is not an obligatory mediator of postburn hypermetabolism. Continuous subcutaneous infusion of NVPlps (2.6 and 12.6 micrograms/100 gm/hr) beneath unseeded burn wounds did not raise metabolic rates above those of burned, unseeded controls. Neither NVP seeding nor LPS infusion resulted in measurable endotoxemia on PBDs 7-8. These results indicate that the LPS released in the colonized burn wound does not serve as either a circulating mediator or the principal inducer of other mediators of postburn hypermetabolism in rats.

Guinea pig model for antibiotic transport across gastric mucosa: inhibitory tissue concentrations of clindamycin against Helicobacter pylori (Campylobacter pylori) following two separate dose regimens.

An animal model for antibiotic secretion across gastric mucosa was developed using adult guinea pigs. Antibiotics were given intramuscularly, and levels in serum and gastric mucosa were measured by high-pressure liquid chromatography at 1, 2, 4, 6, and 8 h postinjection. Mucosal levels of the drugs were measured in the superficial luminal portion of the mucosa, which was removed by mechanical scraping. Clindamycin levels were measured after doses of 10 and 100 mg/kg of body weight. After doses of 100 mg/kg, levels in serum peaked at 15.95 micrograms/ml at 2 h. Gastric mucosa showed a bimodal concentration curve with peaks of 15.91 micrograms/g at 1 h and 25.07 micrograms/g at 4 h. Concentrations in mucosa remained high when levels in serum fell, showing a mucosa/serum ratio of 87.70 after 8 h. At all times, clindamycin levels in mucosa were in excess of the MIC for 90% of the Helicobacter (Campylobacter) pylori strains tested.

Influence of streptozotocin (STZ)-induced diabetes, dextrose diuresis and acetone on cisplatin nephrotoxicity in Fischer 344 (F344) rats.

The following studies examined the impact of the diabetic state on cisplatin nephrotoxicity. This study also investigated the potential mechanisms for diabetes mediated reduction of cisplatin toxicity. A diabetic state was induced in male Fischer 344 (F344) rats after intraperitoneal (i.p.) injection of 27-35 mg/kg STZ. Cisplatin (5 mg/kg, i.p.) nephrotoxicity was examined in normoglycemic and diabetic rats after 48 and 96 h. Cisplatin was nephrotoxic within 96 h to normoglycemic animals as indicated by an increased kidney weight, marked elevations in serum BUN levels as well as significant P less than 0.05) decreases in renal cortical slice accumulation of p-aminohippurate (PAH) and tetraethylammonium (TEA). Cisplatin failed to depress renal cortical slice accumulation of PAH and TEA in the diabetic rats. Cisplatin was also less effective in increasing BUN levels or kidney weight in diabetic rats. Further studies investigated the impact of glycosuric diuresis and ketone bodies on cisplatin nephrotoxicity. Dextrose diuresis of normoglycemic rats failed to reduce the effect of cisplatin on BUN levels, kidney weight and renal cortical slice uptake of PAH and TEA. Acetone pretreatment of normoglycemic rats also did not reduce cisplatin nephrotoxicity. These results indicate: (1) cisplatin nephrotoxicity is attenuated in the experimental diabetic state, (2) diabetes does not reduce cisplatin nephrotoxicity through glycosuric diuresis and (3) ketone body accumulation does not modulate cisplatin nephrotoxicity.

Cephaloridine nephrotoxicity in streptozotocin induced diabetic Fischer 344 (F344) rats.

The purpose of this study was to determine if cephaloridine nephrotoxicity is attenuated in streptozotocin (STZ)-induced diabetic rats. Fischer 344 (F344) rats (205-250 g) were given a single injection (i.p.) of STZ (27-35 mg/kg) or citrate buffer. The nephrotoxicity of (750 mg/kg) cephaloridine (i.p.) was then compared with normoglycemic and 14-day diabetic rats. Increased blood urea nitrogen (BUN) levels as well as diminished renal cortical slice accumulation of tetraethylammonium (TEA) and lactate-stimulated p-aminohippurate (PAH) were measured (P less than 0.05) in normoglycemic rats 48 h after cephaloridine administration. Cephaloridine failed to alter BUN levels and organic ion accumulation in diabetic rats. Diabetes did not totally protect against cephaloridine toxicity since kidney weights were elevated in normoglycemic and diabetic rats 48 h after administration of 750 mg/kg cephaloridine. A series of experiments also measured BUN levels, kidney weight and renal cortical slice uptake of PAH and TEA 24, 48 and 72 h after (1500 mg/kg) cephaloridine administration. Cephaloridine increased (P less than 0.05) kidney wt and decreased PAH and TEA uptake (P less than 0.05) in the normoglycemic group at 24-72 h. No change in kidney wt, PAH or TEA uptake was observed in the diabetic rats. These data indicate diabetes reduces cephaloridine nephrotoxicity.