Adaptive response to hydrogen peroxide in yeast: Induction,time course,and relationship to dose–response models

The assay for trp5 gene conversion and ilv1‐92 reversion in Saccharomyces cerevisiae strain D7 was used to characterize the induction of an adaptive response by hydrogen peroxide (H₂O₂). Effects of a small priming dose on the genotoxic effects of a larger challenge dose were measured in exponential cultures and in early stationary phase. An adaptive response, indicated by smaller convertant and revertant frequencies after the priming dose, occurred at lower priming and challenge doses in young, well‐aerated cultures. Closely spaced priming doses from 0.000975 to 2 mM, followed by a 1 mM challenge, showed that the induction of the adaptive response is biphasic. In exponential cultures it was maximal with a priming dose of 0.125–0.25 mM. Very small priming doses were insufficient to induce the adaptive response, whereas higher doses contributed to damage. A significant adaptive response was detected when the challenge dose was administered 10–20 min after the priming exposure. It was fully expressed within 45 min, and the yeast began to return to the nonadapted state after 4–6 hr. Because of the similarity of the biphasic induction to hormetic curves and the proposal that adaptive responses are a manifestation of hormesis, we evaluated whether the low doses of H₂O₂ that induce the adaptive response show a clear hormetic response without a subsequent challenge dose. Hormesis was not evident, but there was an apparent threshold for genotoxicity at or slightly below 0.125 mM. The results are discussed with respect to linear, threshold, and hormesis dose–response models. Environ. Mol. Mutagen. 54:384–396, 2013. © 2013 Wiley Periodicals, Inc.     

The diagnostic yield of colonoscopy in hospitalized patients. An observational multicenter prospective study.

BackgroundColonoscopy demands a considerable amount of resources, and little is known about its diagnostic yield among inpatients.AimsTo assess indications, diagnostic yield and findings of colonoscopy for inpatients, and to identify risk factors for relevant findings and cancer.MethodsMulticentre, prospective, observational study including 12 hospitals. Consecutive adult inpatients undergoing colonoscopy were evaluated from February through November 2019.Results1,302 inpatients underwent colonoscopy. Diagnostic yield for relevant findings and cancer was 586 (45%) and 112 (8.6%), respectively. Adequate colon cleansing was achieved in 896 (68.8%) patients. Split-dose/same-day regimen was adopted in 847 (65%) patients. Factors associated to relevant findings were age ≥70 years (RR 1.32), male gender (RR 1.11), blood loss (RR 1.22) and adequate cleansing (RR 1.63). Age ≥70 years (RR 2.08), no previous colonoscopy (RR 2.69) and split-dose/same-day regimen (RR 1.59) significantly increased cancer detection. Implementing adequate cleansing and split-dose/same-day regimen in all patients would increase the diagnostic yield for any relevant findings and cancer from 43% to 70% and from 6% to 10%, respectively.ConclusionRelevant colorectal diseases and cancer were frequent among inpatients. Factors associated with detection of relevant findings were identified. Adequate colon cleansing and split-dose/same-day regimen significantly increased colonoscopy diagnostic yield.     

Pattern of Gastric Emptying in Functional Dyspepsia. An Ultrasonographic Study

We assessed the ultrasonographic pattern of gastric emptying in patients with functional dyspepsia, evaluating its relationship with symptoms. Twenty dyspeptic patients, with slight (group A) and severe (group B) symptoms, and 10 controls (group C) underwent ultrasonographic study of gastric emptying by measuring postprandial variations of the antral area at regular intervals. The time at which the antral area returned to the basal value was assumed to be the final emptying time. The final emptying time was significantly longer in both group A (294 +/- 42 min) and group B (340 +/- 36 min) compared to controls (244 +/- 21 min), but no significant difference was observed between them. A significantly (P < 0.05) greater dilation of the antral area was found at 50 min in group B compared to group A patients. A different pattern of antral motor function rather than a delay of gastric emptying correlates with the severity of symtoms in dyspeptic patients.     

Brain perfusion and neuropsychological changes in schizophrenic patients after cognitive rehabilitation

The role of cognitive variables was compared in two single cases of schizophrenia hypofrontality. SPECT procedures and neuropsychological tests were used to study frontal brain function. After cognitive rehabilitation, neuropsychological performance were enhanced in both patients, but only one of them showed enhanced the frontal blood flow. The brain perfusion changes after cognitive rehabilitation could be associated with the cognitive-dependent hypofrontality.     

Cytoreduction combined with intraperitoneal hyperthermic perfusion chemotherapy in advanced/recurrent ovarian cancer patients: The experience of National Cancer Institute of Milan.

AIMS: We report the effects of cytoreductive surgery (CRS) and intraperitoneal hyperthermic perfusion (IPHP) in the treatment of advanced/recurrent epithelial ovarian cancer (EOC) on survival, morbidity and mortality. PATIENTS: Forty EOC patients were studied. Median age was 52.5 years (range: 30-68) and median follow-up 26.1 months (range: 0.3-117.6). Most patients presented advanced disease (stage III/IV). Previous systemic chemotherapy included cisplatin-based, taxol-based or taxol/platinum containing regimens. RESULTS: After the CRS, 33 patients presented no macroscopic residual disease. Five-year overall survival was 15%; the mean overall and progression-free survivals were 41.4 and 23.9 months, respectively. The morbidity, toxicity and mortality rates were 5%, 15% and 0%, respectively. CONCLUSION: Our results suggest that CRS + IPHP merits further evaluation by a formal prospective trial.     

Role of antibiotic sensitivity testing before first-line Helicobacter pylori eradication treatments

BACKGROUND: The resistance of Helicobacter pylori to antibiotics has been advocated as a major cause of treatment failure, and antimicrobial sensitivity testing has been proposed to improve efficacy; however, its role before first-line therapy has not been investigated in detail. AIM: To assess whether antimicrobial sensitivity testing improves the eradication rate of first-line anti-Helicobacter treatments and to compare the effectiveness of ranitidine bismuth citrate and omeprazole in the presence of H. pylori resistance to antibiotics. METHODS: Two hundred and forty-two patients were assigned to either empirical or antimicrobial sensitivity testing-based treatment; within each group, subjects were further randomized to receive ranitidine bismuth citrate, 400 mg b.d., tinidazole, 500 mg b.d., and clarithromycin, 500 mg b.d., or omeprazole, 20 mg b.d., clarithromycin, 500 mg b.d., and amoxicillin, 1 g b.d., for 1 week, with substitution of the resistant antibiotic in the antimicrobial sensitivity testing-based treatment group. RESULTS: Eradication rates were 67% [confidence interval (CI), 55-79%] in the empirical treatment group and 76% (CI, 65-87%) in the antimicrobial sensitivity testing-based group (P=N.S.). The overall success rate was 60% (CI, 51-69%) with omeprazole and 82% (CI, 73-91%) with ranitidine bismuth citrate (P<0.03); the latter overcame antibiotic resistance in 12 of 15 strains vs. zero of eight strains by omeprazole. CONCLUSIONS: Antimicrobial sensitivity testing before first-line treatment does not improve the eradication rate, which is greater when ranitidine bismuth citrate is included in the treatment.