New treatment strategies for non-metastatic rectal cancer

The most widely practiced (standard) treatment of non-metastatic rectal cancer is based on proctectomy with mesorectal excision (partial or total according to the location of the tumor and commonly called TME). Surgery is preceded by CAP50-type chemoradiotherapy (capecitabineand 50 Grays radiation) and performed 6-8 weeks after the end of chemoradiotherapy. The development of new endoscopic, surgical, radiation-based and chemotherapeutic modalities leads surgeons to envisage customized treatment to find the best compromise between functional and oncologic results according to the locoregional extension of the tumor. Superficial lesions are amenable to transanal excision. T2-3 tumors<4cm are amenable to rectal preservation when neoadjuvant treatment obtains a complete response, allowing local excision or close surveillance. Intensification endocavitary radiotherapy and induction and consolidation chemotherapy regimens to avoid recourse to salvage abdomino-perineal resection (APR) are under investigation. For locally advanced rectal cancers (T3-4 and all N+ irrespective of T), the following scenarios can be envisaged: for initially resectable tumors (T3N0, T1-T3N+, circumferential resection margin>2mm), neoadjuvant chemotherapy alone aims to minimize the risk of local recurrence while avoiding the sequelae of radiotherapy. In case of initially non-resectable tumors (T4, circumferential resection margin<1mm), induction chemotherapy before chemoradiotherapy and consolidation chemotherapy after short course radiotherapy provide better results than standard treatment in terms of complete response and recurrence-free survival, and should be routinely proposed in this indication.

Endothelial cell-derived extracellular vesicles exert cardio-protective effect via their protein cargo

Background

Extracellular vesicles (EV) are recognized as carriers of relevant biological effects and have been identified as regulators of cell-to-cell communication contributing to several patho-physiological processes. These processes include angiogenesis/coagulation/tissue repair/inflammation. In ischemia/reperfusion (I/R) settings, along with the direct effects of the I/R itself, paracrine mechanisms associated with the activation of the inflammatory response, primary involving endothelial cells, are crucial drivers of both vessel and cardiomyocyte damage.

Purpose

Since in models of myocardial I/R injury the role of EV released from endothelial cells is still unclear, our hypothesis was to provide insight on this specific topic. To this end, naïve endothelial cell (EC)-derived EV (eEV) and eEV released in response to the pro-inflammatory cytokine interleukin-3 (IL-3) (eEV-IL-3) have been evaluated on different I/R models.

Methods

eEV were characterized by MACSPlex-Exosome-Kit and western blot analysis. For the in-vitro hypoxia-reoxygenation (H/R) experiments, H9c2 or EC were pretreated with eEV, eEV-IL-3 (1x104 EV/cell) or IL-3 (10ng/ml) for 2 hours and then exposed to hypoxia (1% O2, 5% CO2) for additional 2 hours in the presence of eEV, eEV-IL-3 or IL-3 and subsequently reoxygenated (21% O2 and 5% CO2) for 1 hour. To verify the effect of EC treated with eEV, eEV-IL-3 or IL-3 on H9c2 and subjected to H/R protocol, transwell assay was used. At the end of the H/R protocol, cell viability was assessed. For ex-vivo experiments, isolated rat hearts, pretreated with a buffer containing EV (from EC pretreated or not with IL-3), were subjected to 30 minutes global normothermic ischemia and 1 hour reperfusion. Triton infusion was also used as a model of endothelial damage. At the end of I/R, the infarct size was measured and expressed as a percentage of total left ventricular mass (LVM). The role of eNOS/guanylyl-cyclase/MEK1/2 pathways in mediating eEV biological effects was also evaluated using different inhibitors both in in-vitro and ex-vivo models. Finally, protein profiles of eEV and eEV-IL-3 were analyzed using label free mass spectrometry.

Results

eEV and eEV-IL-3 protect EC, but not H9c2 exposed to H/R protocol, while eEV, but not eEV-IL-3-treatment limits I/R injury in the rat heart. Rat hearts pre-treated with triton significantly avoid eEV-induced cardio-protection. Transwell assay showed a reduction of H9C2 mortality after treatment with both eEV and eEV-IL-3. Proteomic analysis revealed that MEK1/2 and the endothelial-NOS (eNOS)-antagonist caveolin-1 were differentially expressed in eEV and eEV-IL-3. The use of eNOS/guanylyl-cyclase/MEK1/2 inhibitors prevented eEV-induced cardio-protection.

Conclusions

These observations indicate that eEV, but not eEV-IL-3, have cardio-protective effects when given as preconditioning agents. We have also shown that the activation of eNOS/GC/MEK1/2 pathway is crucial for eEV-mediated cardio-protection.

Funding Acknowledgement

Type of funding source: None

COVID-19-associated cardiovascular morbidity in older adults: a position paper from the Italian Society of Cardiovascular Researches

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells following binding with the cell surface ACE2 receptors, thereby leading to coronavirus disease 2019 (COVID-19). SARS-CoV-2 causes viral pneumonia with additional extrapulmonary manifestations and major complications, including acute myocardial injury, arrhythmia, and shock mainly in elderly patients. Furthermore, patients with existing cardiovascular comorbidities, such as hypertension and coronary heart disease, have a worse clinical outcome following contraction of the viral illness. A striking feature of COVID-19 pandemics is the high incidence of fatalities in advanced aged patients: this might be due to the prevalence of frailty and cardiovascular disease increase with age due to endothelial dysfunction and loss of endogenous cardioprotective mechanisms. Although experimental evidence on this topic is still at its infancy, the aim of this position paper is to hypothesize and discuss more suggestive cellular and molecular mechanisms whereby SARS-CoV-2 may lead to detrimental consequences to the cardiovascular system. We will focus on aging, cytokine storm, NLRP3/inflammasome, hypoxemia, and air pollution, which is an emerging cardiovascular risk factor associated with rapid urbanization and globalization. We will finally discuss the impact of clinically available CV drugs on the clinical course of COVID-19 patients. Understanding the role played by SARS-CoV2 on the CV system is indeed mandatory to get further insights into COVID-19 pathogenesis and to design a therapeutic strategy of cardio-protection for frail patients.

Social deprivation aggravates post-operative morbidity in carcinologic colorectal surgery: Results of the COINCIDE multicenter study

AIM OF THE STUDY

Evaluate the impact of social deprivation on morbidity and mortality in surgery for colorectal cancer.

METHODS

The COINCIDE prospective cohort included nearly 2,000 consecutive patients operated on for colorectal cancer at the Assistance Publique-Hospitals of Paris (AP-HP) from 2008 to 2010. The data on these patients were crossed with the PMSI administrative database. The European Social Deprivation Index (EDI) was calculated for each patient and classified into five quintiles (quintiles 4 and 5 being the most disadvantaged patients). Thirty-day post-operative morbidity was determined according to the Dindo-Clavien classification, with a Had®Hoc re-analysis of each file. Statistical analysis was performed using the proprietary Q-finder® algorithm.

RESULTS

One thousand two hundred and fifty nine curative colorectal resections were analyzed. Mortality was 2.7% and severe morbidity (Dindo-Clavien≥3) occurred in 16.4%. Mortality was not statistically significantly increased among the most disadvantaged who made up almost two thirds of the population (64.2%). Patients in quintiles 4 and 5 had a statistically significant increase in severe morbidity. The relative risk remained 1.5 even after adjustment for the known risk factors found in the analysis: age>70 years, ASA score, urgency, and laparotomy.

CONCLUSIONS

The EDI represents an independent risk factor for severe morbidity after carcinologic colorectal resection. This study suggests that the determinants of health are multidimensional and do not depend solely on the quality and performance of the care system. The inclusion of this index in our surgical databases is therefore necessary, as is its use in health policy for the distribution of resources.

Elective surgery for tumours of the splenic flexure: a French inter-group (AFC, SFCD, FRENCH, GRECCAR) survey

BACKGROUND

In an elective setting, there is no consensus regarding the type of colectomy that is best for patients with tumors of the splenic flexure: segmental left colectomy (or splenic flexure colectomy), left hemicolectomy or subtotal colectomy (or extended right hemicolectomy). In the United Kingdom, extended right hemicolectomy is preferred by surgeons. The aim of the present survey was to report on the practices in France for this particular tumor location.

METHODS

Between 15/07/17 and 15/10/17, members of two French surgical societies [the French Association of Surgery (AFC) and the French Society of Digestive Surgery (SFCD)] and two French surgical cooperative groups [the French Federation of Surgical Research (FRENCH) and the French Research Group of Rectal Cancer Surgery (GRECCAR)] were solicited by email to answer an online anonymous questionnaire.

RESULTS

A total of 190 out of 420 surgeons participated in this study (response rate 45%). The preferred procedure was splenic flexure colectomy (70%), followed by left hemicolectomy (17%) and subtotal colectomy (13%). The most used surgical approach was laparoscopy (63%), followed by laparotomy (31%) and hand-assisted laparoscopy (6%). Lymph node dissection was extended to the middle colic artery in 29% of splenic flexure colectomies and in 33% of left hemicolectomies. Twenty-nine percent of responders thought that tumors of the splenic flexure had a worse prognosis in comparison with other colonic sites, because of insufficient lymph node dissection (73%) or a more advanced stage (50%) at diagnosis. However, this opinion did not change the type of colectomy performed.

CONCLUSIONS

There is a strong consensus in France to operate tumors of the splenic flexure with a splenic flexure colectomy and lymph node dissection limited to the left colic artery.

Intralesional Beta-Interferon Treatment of Cervical Intraepithelial Neoplasia Associated with Human Papillomavirus Infection

Aims and backround

Interferons (IFN) have offered considerable advances in the therapy of genital warts even those associated with cervical intraepithelial neoplasia (CIN); intralesional therapy either alone or in combination with other modalities such as cryosurgery and laser surgery provides improved clearing and cure of these often recalcitrant lesions. The purpose of this study was to evaluate the effectiveness of intralesional IFN therapy in patients with CIN associated with human papillomavirus (HPV) infection.

Methods

Beta-IFN was injected intra-perilesionally into the cervix in 41 patients with CIN associated with HPV infection.

Results

The regimen of 3 million international units (IU) injected intralesionally daily in the 1st week and 3 times a week in the 2nd and 3rd weeks for a total of 11 injections and a total dosage of 33 million IU yielded an 80 percent cure rate and may be more advantageous than other treatment options in certain instances. Cytocolposcopic and histologic examination was carried out before and after treatment and 24 lesions were also analyzed for type-specific papillomaviruses using in situ DNA hybridization. CIN disappeared in 33 patients 6 months after the end of therapy. Side effects of intralesional IFN therapy are dose related and for the most part readily tolerated.

Conclusions

Intralesional IFN proved to be effective treatment for CIN associated with HPV infection (cure rate: 80%) and well accepted because hospitalization is not required and no important side effects occur.

High-Grade Cervical Intraepithelial Neoplasia (CIN) in Pregnancy: Clinicotherapeutic Management

An increasing incidence of cervical intraepithelial neoplasia (CIN) among young women has been noticed in recent years. For this reason pregnancy might represent a peculiar opportunity to undergo cytocolposcopic examination for those women who do not take part in a screening program for cervical carcinoma. Diagnosis of CIN during pregnancy poses the question of the management of this disease and particularly of whether it is better to treat the lesion or not during pregnancy. To contribute to the solution of this issue we initiated a study on the management of high-grade CIN in pregnancy.

Material and methods

Five hundred and seventy-one pregnant women underwent cytologic, colposcopic and, when necessary, histologic examination. Those in whom a CIN was discovered in the first four months of gestation underwent laser conization. When the diagnosis of CIN was made after the sixteenth week of gestation, cytocolposcopic monitoring was performed every eighth week during pregnancy and two months after childbirth. Laser conization was performed under colposcopic guidance in the outpatient setting in all cases. All treated patients were submitted to cytologic, colposcopic and, if necessary, histologic examination every third month in the first year after treatment, every sixth month in the second year and yearly from the third year onwards.

Results

In 14 (2.4%) of the 571 examined women a CIN III was discovered, 6 of which associated with a human papilloma virus (HPV) infection. Of these, 8 patients, whose diagnosis was made within the sixteenth week of pregnancy, underwent laser conization. In one case a minor hemorrhage occurred during treatment. Two patients reported minor bleeding up to ten days after treatment. No major hemorrhages or cervical stenosis were observed. Histologic examination of the cones confirmed the preoperative diagnosis based on cervical biopsies and the lesion was entirely removed by conization in all cases. Seven of the 8 patients who underwent laser conization during pregnancy had a spontaneous delivery at term. The remaining patient, who had had a previous cesarean section, was again delivered by cesarean section. All treated patients were cured after the first-year follow-up visit. In 6 patients CIN was diagnosed after the sixteenth week of pregnancy. These women underwent cytocolposcopic examination every eighth week during pregnancy and two months after delivery, when the cervical changes associated with gestation had disappeared. Four of these patients showed persistence of CIN at postpartum follow-up and therefore underwent laser conization. In two patients spontaneous regression of the lesion was observed. In no case did progression to invasive carcinoma occur.

Conclusions

Given the increasing incidence of CIN in young women, the beginning of pregnancy may represent a peculiar opportunity for all pregnant women who do not take part in cervical screening programs to undergo a cytocolposcopic examination. In case of a diagnosis of high-grade CIN within the first 16 weeks of pregnancy, a conservative excisional treatment, which does not expose the pregnancy to any risk, should be carried out in order to confirm the intraepithelial localization of the lesion.

The accuracy of preoperative imaging in measuring the length of the ileocolic segment affected by Crohn's disease: a prospective cohort study

AIM

The study aimed to evaluate the accuracy of imaging for measurement of the length of the ileocolic segment affected by Crohn's disease.

METHOD

Fifty-four consecutive patients who underwent resection between 2011 and 2014 for ileocolic Crohn's disease were prospectively studied. All had preoperative MR or CT enterography. Two independent radiologists measured the length of the diseased intestinal segment. The measurements were compared with the length of disease assessed on pathology of the non-fixed surgical specimen.

RESULTS

The median preoperative length of the Crohn's disease segment on imaging was 20.5 (2-73) cm and 20 (3-90) cm, as measured by the two radiologists. Interobserver agreement was substantial (κ = 0.69) with a correlation coefficient (r) of 0.82 (P < 0.001). The median length of the Crohn's disease segment on pathological examination was 16.5 (2-75) cm and was closely correlated with the radiological measurement (r = 0.76, P < 0.001). The length of the Crohn's disease segment on imaging was correct to within 5 cm of the value on pathology. It was correct in 30 (55%) patients and was underestimated and overestimated in 6 (11.1%) and 18 (33.3%). A length of disease of less than 20 cm found on imaging in 26 patients was confirmed in 25 (96%) on pathology, whereas a length of more than 20 cm found on imaging in 28 patients was confirmed in 18 (64%) on pathology. The sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of imaging for predicting a length of less than 20 cm were 71%, 95%, 96%, 64% and 79%.

CONCLUSION

Imaging accurately identifies the length of the ileocolic segment of Crohn's disease when it is 20 cm or less on pathological examination. In patients with more extensive disease, imaging tends to overestimate the length and should be interpreted with caution.

Outcome of emergency surgery for severe neuroleptic-induced colitis: results of a prospective cohort

AIM

The study evaluated the outcome of severe acute antipsychotic (neuroleptic) drug related colitis requiring emergency surgery.

METHOD

From 2009 to 2014, 20 patients underwent emergency surgery for acute and severe neuroleptic-related ischaemic colitis. Neuroleptic-induced colitis was defined as another cause besides inflammatory, infectious or ischaemic colitis with a relationship to treatment by antipsychotic drugs.

RESULTS

The main drugs involved were cyamemazine (n = 9, 45%), loxapine (n = 5, 25%), haloperidol (n = 4, 20%) and alimemazine (n = 4, 20%). Most (n = 14, 70%) patients presented with haemodynamic instability requiring massive resuscitation and vasopressive drugs. CT signs of digestive impairment were found in 13 (65%) patients having emergency surgery. The lesions were pancolonic in 40%; transparietal necrosis was found in 45% and 15% had colonic perforation. Twelve (60%) patients had total or subtotal colectomy and eight (40%) a segmental colectomy with colostomy or ileostomy in all cases. The postoperative mortality was 15% and morbidity was 70%, necessitating surgical reintervention in two (10%) patients. Of the 17 surviving patients, 11 (64.7%) had restoration of intestinal continuity after a median delay of 103 days, with a postoperative morbidity rate of 36.3%. In the intent-to-treat population, the permanent stoma rate was 30%.

CONCLUSION

The morbidity and mortality of surgery for neuroleptic-drug-induced colitis is higher than for colitis due to other causes. A better knowledge of this condition should lead to early diagnosis.

The innovative "Bio-Oil Spread" prevents metabolic disorders and mediates preconditioning-like cardioprotection in rats

BACKGROUND AND AIMS

Obesity is often associated with an increased cardiovascular risk. The food industry and the associated research activities focus on formulating products that are a perfect mix between an adequate fat content and health. We evaluated whether a diet enriched with Bio-Oil Spread (SD), an olive oil-based innovative food, is cardioprotective in the presence of high-fat diet (HFD)-dependent obesity.

METHODS AND RESULTS

Rats were fed for 16 weeks with normolipidic diet (ND; fat: 6.2%), HFD (fat: 42%), and ND enriched with SD (6.2% of fat + 35.8% of SD). Metabolic and anthropometric parameters were measured. Heart and liver structures were analyzed by histochemical examination. Ischemic susceptibility was evaluated on isolated and Langendorff-perfused cardiac preparations. Signaling was assessed by Western blotting. Compared to ND rats, HFD rats showed increased body weight and abdominal obesity, dyslipidemia, and impaired glucose tolerance. Morphological analyses showed that HFD is associated with heart and liver modifications (hypertrophy and steatosis, respectively), lesser evident in the SD group, together with metabolic and anthropometric alterations. In particular, IGF-1R immunodetection revealed a reduction of hypertrophy in SD heart sections. Notably, SD diet significantly reduced myocardial susceptibility against ischemia/reperfusion (I/R) with respect to HFD through the activation of survival signals (Akt, ERK1/2, and Bcl2). Systolic and diastolic performance was preserved in the SD group.

CONCLUSIONS

We suggest that SD may contribute to the prevention of metabolic disorders and cardiovascular alterations typical of severe obesity induced by an HFD, including the increased ischemic susceptibility of the myocardium. Our results pave the way to evaluate the introduction of SD in human alimentary guidelines as a strategy to reduce saturated fat intake.

Cardiophrenic angle lymph node is an indicator of metastatic spread but not specifically peritoneal carcinomatosis in colorectal cancer patients: Results of a prospective validation study in 91 patients

BACKGROUND

The presence of cardiophrenic angle lymph node (CPALN) has been associated with the risk of peritoneal carcinomatosis (PC) in high risk colon cancer patients. Its accuracy to predict PC and its prognostic value in non-selected CRC patients has not been validated prospectively.

METHODS

From 2011 to 2013, all patients undergoing colectomy for colon cancer were included prospectively. Presence of CPALN was assessed on preoperative computed tomography scan by two radiologists. Surgical exploration was used as reference for the diagnosis of PC. Factors associated with presence of CPALN and progression-free survival were analyzed.

RESULTS

Ninety one patients fulfilled inclusion criteria. CPALN was detected in 36 patients (39.5%) on CT scan. At surgical exploration, PC was found in 6 patients (6.5%). Sensitivity, specificity, negative predictive value, positive predictive value and overall accuracy of CPALN on CT scan for predicting PC were 67%, 62%, 96%, 11% and 63% respectively. In multivariate analysis, the presence of distant metastases whatever the site was associated with the presence of CPALN (p = 0.03; hazard ratio HR = 3.8; confidence interval CI 95% = 1.1-13.3). In the multivariate analysis, only vascular involvement (p = 0.034, HR = 3.574, CI 95% = 1.10-11.60) was associated with progression-free survival whereas CPALN was not found to predict outcome (p = 0.893).

CONCLUSION

CPALN is a common finding in non-selected colon cancer patients. Although in the absence of CPALN, PC can almost be excluded, its value for the diagnosis of PC is limited. Our findings support that CPALN is mainly an indicator of metastatic spread of the tumor.

pGlu-serpinin protects the normotensive and hypertensive heart from ischemic injury

Serpinin peptides derive from proteolytic cleavage of Chromogranin-A at C-terminus. Serpinin and the more potent pyroglutaminated-serpinin (pGlu-Serp) are positive cardiac β-adrenergic-like modulators, acting through β1-AR/AC/cAMP/PKA pathway. Because in some conditions this pathway and/or other pro-survival pathways, activated by other Chromogranin-A fragments, may cross-talk and may be protective, here we explored whether pGlu-Serp cardioprotects against ischemia/reperfusion injury under normotensive and hypertensive conditions. In the latter condition, cardioprotection is often blunted because of the limitations on pro-survival Reperfusion Injury Salvage Kinases (RISK) pathway activation. The effects of pGlu-Serp were evaluated on infarct size (IS) and cardiac function by using the isolated and Langendorff perfused heart of normotensive (Wistar Kyoto, WKY) and spontaneously hypertensive (SHR) rats exposed to ischemic pre-conditioning (PreC) and post-conditioning (PostC). In both WKY and SHR rat, pGlu-Serp induced mild cardioprotection in both PreC and PostC. pGlu-Serp administered at the reperfusion (Serp-PostC) significantly reduced IS, being more protective in SHR than in WKY. Conversely, left ventricular developed pressure (LVDevP) post-ischemic recovery was greater in WKY than in SHR. pGlu-Serp-PostC reduced contracture in both strains. Co-infusion with specific RISK inhibitors (PI3K/Akt, MitoKATP channels and PKC) blocked the pGlu-Serp-PostC protective effects. To show direct effect on cardiomyocytes, we pre-treated H9c2 cells with pGlu-Serp, which were thus protected against hypoxia/reoxygenation. These results suggest pGlu-Serp as a potential modulatory agent implicated in the protective processes that can limit infarct size and overcome the hypertension-induced failure of PostC.

Pathological response of locally advanced rectal cancer to preoperative chemotherapy without pelvic irradiation

AIM

Pathological response to chemotherapy without pelvic irradiation is not well defined in rectal cancer. This study aimed to evaluate the objective pathological response to preoperative chemotherapy without pelvic irradiation in middle or low locally advanced rectal cancer (LARC).

METHODS

Between 2008 and 2013, 22 patients with middle or low LARC (T3/4 and/or N+ and circumferential resection margin < 2 mm) and synchronous metastatic disease or a contraindication to pelvic irradiation underwent rectal resection after preoperative chemotherapy. The pathological response of rectal tumour was analysed according to the Rödel tumour regression grading (TRG) system. Predictive factors of objective pathological response (TRG 2-4) were analysed.

RESULTS

All patients underwent rectal surgery after a median of six cycles of preoperative chemotherapy. Of these, 20 (91%) had sphincter saving surgery and an R0 resection. Twelve (55%) patients had an objective pathological response (TRG 2-4), including one complete response. Poor response (TRG 0-1) to chemotherapy was noted in 10 (45%) patients. In univariate analyses, none of the factors examined was found to be predictive of an objective pathological response to chemotherapy. At a median follow-up of 37.2 months, none of the 22 patients experienced local recurrence. Of the 19 patients with Stage IV rectal cancer, 15 (79%) had liver surgery with curative intent.

CONCLUSION

Preoperative chemotherapy without pelvic irradiation is associated with objective pathological response and adequate local control in selected patients with LARC. Further prospective controlled studies will address the question of whether it can be used as a valuable alternative to radiochemotherapy in LARC.

Redox signalling and cardioprotection: translatability and mechanism

The morbidity and mortality from coronary artery disease (CAD) remain significant worldwide. The treatment for acute myocardial infarction has improved over the past decades, including early reperfusion of culprit coronary arteries. Although it is mandatory to reperfuse the ischaemic territory as soon as possible, paradoxically this leads to additional myocardial injury, namely ischaemia/reperfusion (I/R) injury, in which redox stress plays a pivotal role and for which no effective therapy is currently available. In this review, we report evidence that the redox environment plays a pivotal role not only in I/R injury but also in cardioprotection. In fact, cardioprotective strategies, such as pre- and post-conditioning, result in a robust reduction in infarct size in animals and the role of redox signalling is of paramount importance in these conditioning strategies. Nitrosative signalling and cysteine redox modifications, such as S-nitrosation/S-nitrosylation, are also emerging as very important mechanisms in conditioning cardioprotection. The reasons for the switch from protective oxidative/nitrosative signalling to deleterious oxidative/nitrosative/nitrative stress are not fully understood. The complex regulation of this switch is, at least in part, responsible for the diminished or lack of cardioprotection induced by conditioning protocols observed in ageing animals and with co-morbidities as well as in humans. Therefore, it is important to understand at a mechanistic level the reasons for these differences before proposing a safe and useful transition of ischaemic or pharmacological conditioning. Indeed, more mechanistic novel therapeutic strategies are required to protect the heart from I/R injury and to improve clinical outcomes in patients with CAD.

Spontaneous regression of low-grade cervical intraepithelial lesions is positively improved by topical bovine colostrum preparations (GINEDIE®). A multicentre, observational, italian pilot study

OBJECTIVES

Human papillomavirus (HPV) is the causal agent of cervical cancer. The great majority of abnormal Pap test results - almost 90% - is referrable to either atypical squamous intraepithelial lesion or CIN1. For these lesions, worldwide agreement exists concerning the high rate - ranging from 40% to 70% - of spontaneous regression over a period of 1-5 years. Host's immune response is a key point influencing the natural history of these conditions. Bovine colostrum is a natural agent positively promoting several immune activities against bacterial and viral agents. The aim of this report was to evaluate the potential positive effect of bovine colostrum-containing vaginal tablets administered to CIN1 diagnosed patients in a prospective trial in regards to spontaneous regression rate.

PATIENTS AND METHODS

A series of 256 consecutive patients with histologically proven CIN1 recruited in a multicentre, observational, Italian study. Patients have been enrolled in a 24-weeks protocol of treatment and re-tested at the end of the study. Rates of regression have been recorded.

RESULTS

Overall regression rate to a negative histology at the end of the 6 month follow up was 75.5%.

CONCLUSIONS

Regression to normal histology was observed in a very high rate of cases in a very short period compared to the natural history of these lesions. CIN1 patients could benefit from bovine colostrum topical administration in terms of significantly shortening the regression time.

Number of examined lymph nodes and nodal status assessment in pancreaticoduodenectomy for pancreatic adenocarcinoma

BACKGROUND

The accuracy of the assessment of the nodal status in resected cephalic pancreatic adenocarcinoma (PA) depends on the number of examined lymph nodes (NELN). This study assesses the impact of the NELN on N staging and survival and propose a minimal number of examined lymph nodes (MNELN) ensuring reliability of the pN status determination.

METHODS

188 consecutive patients treated by pancreaticoduodenectomy (PD) for PA. Correlations between NELN and survivals of pN0 and pN1 groups and with the rate of pN1 patients were studied. A probability model based on the binomial law was built to estimate the MNELN able to detect pN1 patients with a sensitivity ≥ 95%.

RESULTS

Overall and disease free 5-year survivals were 27.2% and 24.6% respectively. 135 patients (71.8%) were staged pN1. The median NELN was 17 (range 0-68). Overall and disease free survivals of pN1 patients were not related to NELN. The influence of NELN on survival in pN0 patients due to stage migration did not reach significance. The probability model showed that a MNELN of 16 nodes was required to detect pN1 patients with a sensitivity of 95%.

CONCLUSION

A MNELN of 16 is required to assess pN status and should be considered as a quality criterion in future studies and trials on PD for PA.

Cardioprotection against ischemia/reperfusion injury and chromogranin A-derived peptides

Chromogranin A (CgA) is produced by cells of the sympathoadrenal system and by human ventricular myocardium. In the clinical setting CgA has been mainly used as a marker of neuroendocrine tumors, but in the last decade a plenty of data have been published on the role of CgA and its derived peptides, particularly catestatin and vasostatin, in the regulation of cardiovascular function and diseases, including heart failure and hypertension. CgA-derived peptides, namely catestatin and vasostatin, may exert negative inotropic and lusitropic effects on mammalian hearts. As such CgA and its derived peptides may be regarded as mediators of a complex feedback system able to modulate the exaggerated release of catecholamines. This system may be also interpreted as an attempt for compensatory cardioprotective response against myocardial injury in the pre and postischemic scenarios. In fact, while vasostatin can trigger cardioprotective effects akin ischemic preconditioning (protection is triggered before ischemia), catestatin is a potent cardioprotective agent in the early post-ischemic phase, acting like a postconditioning agent (protection is triggered at the onset of reperfusion). Admittedly, the exact mechanism of cardioprotection of this system is far from being fully understood. Interestingly, both vasostatin and catestatin have shown to be able to activate multiple cardioprotective pathways. In particular, these two CgA-derived peptides may induce nitric oxide dependent pathway, which may play a pivotal role in cardioprotection against ischemia/reperfusion injury. Here, we review the literature about the cardiac effects of catestatin and vasostatin, the mechanisms of myocardial injury and protection and the role of CgA derived peptides in cardioprotection.

Contribution of CXCR4 and SMAD4 in predicting disease progression pattern and benefit from adjuvant chemotherapy in resected pancreatic adenocarcinoma

BACKGROUND

Prognosis of patients with pancreatic adenocarcinoma is poor. Many prognostic biomarkers have been tested, but most studies included heterogeneous patients. We aimed to investigate the prognostic and/or predictive values of four relevant biomarkers in a multicentric cohort of patients.

PATIENTS AND METHODS

A total of 471 patients who had resected pancreatic adenocarcinoma were included. Using tissue microarray, we assessed the relationship of biomarker expressions with the overall survival: Smad4, type II TGF-β receptor, CXCR4, and LKB1.

RESULTS

High CXCR4 expression was found to be the only independent negative prognostic biomarker [hazard ratio (HR) = 1.74; P < 0.0001]. In addition, it was significantly associated with a distant relapse pattern (HR = 2.19; P < 0.0001) and was the strongest prognostic factor compared with clinicopathological factors. In patients who did not received adjuvant treatment, there was a trend toward decrease in the overall survival for negative Smad4 expression. Loss of Smad4 expression was not correlated with recurrence pattern but was shown to be predictive for adjuvant chemotherapy (CT) benefit (HR = 0.59; P = 0.002).

CONCLUSIONS

CXCR4 is a strong independent prognostic biomarker associated with distant metastatic recurrence and appears as an attractive target to be evaluated in pancreatic adenocarcinoma. Negative SMAD4 expression should be considered as a potential predictor of adjuvant CT benefit.

Previous transanal full-thickness excision increases the morbidity of radical resection for rectal cancer

AIM

The aim of the study was to determine the impact of primary full-thickness transanal excision (TAE) on the morbidity rate following radical rectal resection for cancer.

METHOD

Fourteen consecutive patients underwent radical resection for lower third rectal cancer following full-thickness TAE without closure of the defect. They were compared with 25 matched patients from a prospective database of 275 rectal resections who had undergone radical resection without previous TAE for lower third rectal cancer (control group). The confounding factors were: age, sex, body mass index (BMI), classification according to the American Society of Anaesthesiologists, administration of neoadjuvant radiotherapy before rectal resection, tumour stage and type of surgical procedure.

RESULTS

There were no deaths. Overall morbidity was 64.3% in the TAE group and 32% in the control group (P = 0.112). Surgical complications were significantly more frequent in the former (57.1%vs 20%; P = 0.048). The frequency of specific surgical site complications, including anastomotic complications and pelvic abscess formation requiring surgical drainage, was significantly higher in the TAE group than in the control group (42.8%vs 8%; P = 0.032). In univariate analysis, the only factors associated with specific surgical site complications were BMI > 27 and TAE before rectal resection.

CONCLUSION

This case-matched study suggests that previous full-thickness TAE increases the risk of surgical complications after radical resection for lower third rectal cancer, including anastomotic dehiscence and pelvic sepsis.

Salvage colectomy for endoscopically removed malignant colon polyps: is it possible to determine the optimal number of lymph nodes that need to be harvested?

AIM

The total number of lymph nodes examined after salvage colectomy for endoscopically removed malignant polyps was evaluated and an attempt was made to determine whether there was an optimal number of lymph nodes that should be harvested.

METHOD

From 2000 to 2009, 531 patients underwent segmental resection for non-metastatic colon cancer. Of these, 22 underwent a salvage colectomy for an endoscopically removed malignant polyp, the main indication for which was a resection margin of < 1 mm. The surgical procedure was identical to that used for all colon cancers.

RESULTS

The mean number of lymph nodes examined was 11.6 ± 7.6 for the 22 patients with an endoscopically removed malignant polyp and 26.2 ± 13.9 for the remaining 509 patients (P = 0.0006). Fewer than 12 lymph nodes were examined in 62 (12%) of the 509 patients and in 13 (59%) of the 22 patients with an endoscopically removed malignant polyp (P < 0.0001). In the group of 22 patients who underwent a salvage colectomy, the total number of lymph nodes examined ranged from 2 to 33. At a mean follow up of 41 ± 15.6 months, no local or distant recurrence was observed in the 22 patients.

CONCLUSION

The total number of lymph nodes examined after colectomy for endoscopically removed malignant polyps varies and is less than the recommended number of 12 in most cases: this does not appear to have long-term prognostic significance. There is no biological reason to explain this clinical observation.

Where does pelvic nerve injury occur during rectal surgery for cancer?

AIM

Optimal treatment of rectal adenocarcinoma involves total mesorectal excision with nerve-preserving dissection. Urinary and sexual dysfunction is still frequent following these procedures. Improved knowledge of pelvic nerve anatomy may help reduce this and define the key anatomical zones at risk.

METHOD

The MEDLINE database was searched for available literature on pelvic nerve anatomy and damage after rectal surgery using the key words 'autonomic nerve', 'pelvic nerve', 'colorectal surgery', and 'genitourinary dysfunction'. All relevant French and English publications up to May 2010 were reviewed. Reviewed data were illustrated using 3D reconstruction of the foetal pelvis.

RESULTS

The ligation of the inferior mesenteric artery and dissection of the retrorectal space can cause damage to the superior hypogastric plexus and/or hypogastric nerve. Anterolateral dissection in the 'lateral ligament' area and division of Denonvilliers' fascia can damage the inferior hypogastric plexus and efferent pathways. Perineal dissection can indirectly damage the pudendal nerve.

CONCLUSIONS

In most cases, the pelvic nerves can be preserved during rectal surgery. Complete oncological resection may require dissection close to the nerves where the tumour is located anterolaterally where it is fixed and when the pelvis is narrow.

Post-ischaemic activation of kinases in the pre-conditioning-like cardioprotective effect of the platelet-activating factor

AIM

Platelet-activating factor (PAF) triggers cardiac pre-conditioning against ischemia/reperfusion injury. The actual protection of ischaemic pre-conditioning occurs in the reperfusion phase. Therefore, we studied in this phase the kinases involved in PAF-induced pre-conditioning.

METHODS

Langendorff-perfused rat hearts underwent 30 min of ischaemia and 2 h of reperfusion (group 1, control). Before ischaemia, group 2 hearts were perfused for 19 min with PAF (2 x 10(-11) M); groups 3-5 hearts were co-infused during the initial 20 min of reperfusion, with the protein kinase C (PKC) inhibitor chelerythrine (5 x 10(-6) M) or the phosphoinositide 3-kinase (PI3K) inhibitor LY294002 (5 x 10(-5) M) and atractyloside (2 x 10(-5) M), a mitochondrial permeability transition pore (mPTP) opener respectively. Phosphorylation of PKCepsilon, PKB/Akappat, GSK-3beta and ERK1/2 at the beginning of reperfusion was also checked. Left ventricular pressure and infarct size were determined.

RESULTS

PAF pre-treatment reduced infarct size (33 +/- 4% vs. 64 +/- 5% of the area at risk of control hearts) and improved pressure recovery. PAF pre-treatment enhanced the phosphorylation/activation of PKCepsilon, PKB/Akappat and the phosphorylation/inactivation of GSK-3beta at reperfusion. Effects on ERK1/2 phosphorylation were not consistent. Infarct-sparing effect and post-ischaemic functional improvement induced by PAF pre-treatment were abolished by post-ischaemic infusion of either chelerythrine, LY294002 or atractyloside.

CONCLUSIONS

The cardioprotective effect exerted by PAF pre-treatment involves activation of PKC and PI3K in post-ischaemic phases and might be mediated by the prevention of mPTP opening in reperfusion via GSK-3beta inactivation.

[Functional outcome after hand-sewn versus stapled colonic J pouch anastomosis for rectal carcinoma]

STUDY AIM

The aim of this study was to compare the surgical and functional results of hand-sewn and stapled colonic J-pouch anastomoses after proctectomies for cancer.

PATIENTS AND METHODS

Over a 6-year period, 120 patients had a laparotomic conservative rectal excision with total mesorectal excision but without intersphincteric dissection, for cancer of the mid- and lower rectum: the colonic J-pouch anastomosis was hand-sewn for 49 and stapled for 71 patients. The functional results were assessed at 1 year, by a questionnaire completed by the patient.

RESULTS

Morbidity was 37% in the hand-sewn group and 38% in the stapled group (ns). Mean duration of surgery in the hand-sewn group was 288 minutes and in the stapled group, 246 minutes (p<0.001). At 1 year, the rate of perfect continence was 71% for the hand-sewn group and 76% for the stapled group (ns). Significantly, more patient from the hand-sewn groups used enemas (16% versus 3%, p<0.005). On the other hand, there was no significant difference between the two groups for wearing protection, urgency, number of stools a day or gas/stool discrimination.

CONCLUSIONS

There is no major difference in either the surgical or functional results between hand-sewn or stapled colonic J-pouch anastomosis by laparotomy for rectal cancer. Because it is simpler and faster to perform, a stapled pouch is preferable when the tumor site so permits.

Mesenchymal stem cell interaction with a non-woven hyaluronan-based scaffold suitable for tissue repair

The fabrication of biodegradable 3-D scaffolds enriched with multipotent stem cells seems to be a promising strategy for the repair of irreversibly injured tissues. The fine mechanisms of the interaction of rat mesenchymal stem cells (rMSCs) with a hyaluronan-based scaffold, i.e. HYAFF(R)11, were investigated to evaluate the potential clinical application of this kind of engineered construct. rMSCs were seeded (2 x 10(6) cells cm(-2)) on the scaffold, cultured up to 21 days and analysed using appropriate techniques. Light (LM), scanning (SEM) and transmission (TEM) electron microscopy of untreated scaffold samples showed that scaffolds have a highly porous structure and are composed of 15-microm-thick microfibres having a rough surface. As detected by trypan blue stain, cell adhesion was high at day 1. rMSCs were viable up to 14 days as shown by CFDA assay and proliferated steadily on the scaffold as revealed by MTT assay. LM showed rMSCs in the innermost portions of the scaffold at day 3. SEM revealed a subconfluent cell monolayer covering 40 +/- 10% of the scaffold surface at day 21. TEM of early culture showed rMSCs wrapping individual fibres with regularly spaced focal contacts, whereas confocal microscopy showed polarized expression of CD44 hyaluronan receptor; TEM of 14-day cultures evidenced fibronexus formation. Immunohistochemistry of 21-day cultures showed that fibronectin was the main matrix protein secreted in the extracellular space; decorin and versican were seen in the cell cytoplasm only and type IV collagen was minimally expressed. The expression of CD90, a marker of mesenchymal stemness, was found unaffected at the end of cell culture. Our results show that HYAFF(R)11 scaffolds support the adhesion, migration and proliferation of rMSCs, as well as the synthesis and delivery of extracellular matrix components under static culture conditions without any chemical induction. The high retention rate and viability of the seeded cells as well as their fine modality of interaction with the substrate suggest that such scaffolds could be potentially useful when wide tissue defects are to be repaired as in the case of cartilage repair, wound healing and large vessel replacement.

Comparison of the number of uterine myomas detected by in-office transvaginal ultrasonography removed by laparotomic myomectomy: preoperative work-up concerns

PURPOSE OF INVESTIGATION

To assess the ability of detecting the number of uterine myomas by transvaginal ultrasonography (TVS) performed supporting the clinical examination of general gynecologists' office practice.

METHODS

A retrospective comparison of the number of myomas revealed by preoperative in-office TVS and documented after laparotomic myomectomy was conducted in 110 consecutive premenopausal patients referred for surgery.

RESULTS

The sensitivity of TVS in revealing the exact number of myomas was 59.4% in the whole series. In the subgroup of 88 patients with a preoperative diagnosis of three or fewer myomas TVS missed at least one myoma in 31 (35.2%) cases, achieving a 64.8% sensitivity. Among the 72 women diagnosed with one myoma at preoperative TVS, 19 (26.4%) resulted to have two or more myomas at the end of surgery, reaching a 73.6% sensitivity of TVS in revealing the exact number of myomas.

CONCLUSIONS

In-office TVS reinforces the clinical diagnosis of uterine myomas but it often fails in the detection of their number, resulting in a poor preoperative characterization of patients. The fact that one myoma may be overlooked in one-third of patients theoretically eligible for laparoscopic conservative surgery may motivate the implementation of US diagnosis when laparoscopic myomectomy is considered.

Presentation and prognosis of local recurrence after total mesorectal excision

OBJECTIVE

The aim of this study was to describe the presentation, treatment and prognosis of local recurrences following total mesorectal excision for rectal adenocarcinoma.

METHOD

Between 1999 and 2002, 201 patients were treated with total mesorectal excision for mid or low rectal cancer and were followed up prospectively.

RESULTS

Overall 2-year survival was 85%. The 2-year recurrence rate was 8%. Eighteen patients developed local recurrence at 3-60 months. Nine recurrences originated from the pelvic sidewall. These recurrences were symptomatic in 90% of patients. Only two patients were reoperated with a R0 resection and were alive without local recurrence after 19 and 31 months. The seven others died within 9 months. Nine recurrences originated from an anastomotic suture line. Only two had symptoms. A R0 surgical resection was performed in all patients with a 67% sphincter conservation rate. After 26-months of median follow-up (range 7-58), all patients were alive.

CONCLUSION

Half of the local recurrence after total mesorectal excision was located at the anastomotic site. Rectoscopic examination should be performed regularly to detect these anatomotic recurrences that are accessible to a R0 itérative resection.

Synergistic effects against post-ischemic cardiac dysfunction by sub-chronic nandrolone pretreatment and postconditioning: role of beta2-adrenoceptor

Beta(2)-adrenoreceptor overexpression is beneficial against ischemia/reperfusion (I/R) injury. Whether beta-adrenoreceptors are involved in postconditioning (PostC) is unknown. We investigated whether nandrolone-decanoate (ND)-pretreatment can modulate (1) beta-adrenoreceptor expression and (2) post-ischemic cardiac function in response to I/R and PostC. Finally, we tested whether cardioprotection can be prevented by the inhibition of beta(2)-adrenoreceptors. Isolated rat hearts from ND pretreated (15 mg/kg/day i.m., for 14 days) and untreated-animals underwent 30-min ischemia and 120-min reperfusion. In subgroups, at the end of ischemia a PostC protocol (five cycles of 10-s reperfusion and 10-s ischemia) was applied and/or a beta(2)-adrenoreceptor blocker, ICI-118.551 (10 microM), was infused. Left ventricular pressure (LVP) was measured with an electromanometer, and infarct-size was evaluated using nitro-blue-tetrazolium staining. ND-pretreatment increased beta(2)-adrenoreceptor expression, but did not alter cardiac-weight, LVP and maximum rate of increase of LVP (dP/dt(max)). After I/R, infarct-size was smaller in ND-pretreatment than in untreated-animals. Infarct-size was also reduced by PostC, both in untreated and ND-pretreated animals. Contracture was less marked in ND-pretreated animals. PostC reduced contracture in both ND-pretreated and untreated hearts. Moreover, PostC improved post-ischemic recovery of developed LVP and dP/dt(max) much more in earts of ND-pretreated than untreated-animals. ICI-118.551 abolished ND protection and PostC-protection both in ND-pretreated and untreated hearts. Data show that two-weeks ND-pretreatment induces 1) an overexpression of beta(2)-ARs without cardiac hypertrophy and 2) improves the post-ischemic diastolic and systolic cardiac function. Intriguingly, ND-pretreatment potentiates the improvement of systolic function induced by postconditioning via beta(2)-adrenoreceptor activation.

The platelet activating factor triggers preconditioning-like cardioprotective effect via mitochondrial K-ATP channels and redox-sensible signaling

Endogenous platelet activating factor (PAF) is involved in heart ischemic preconditioning. PAF can also afford pharmacological preconditioning. We studied whether mitochondrial-ATP-sensitive K(+) (mK(ATP)) channels and reactive oxygen species (ROS) are involved in PAF-induced cardioprotection. In Group 1 control hearts, Langendorff-perfused rat hearts underwent 30 min ischemia and 2 hours of reperfusion. Group 2 hearts, before ischemia, were perfused for 19 min with PAF (2x10(-11) M); Groups 3 and 4 hearts were co-infused with PAF and N-acetyl-L-cysteine or 5-hydroxydecanoate to scavenge ROS or to block mK(ATP) channels, respectively. Left ventricular pressure and infarct size were determined. PAF-pretreatment reduced infarct size (33 +/- 4% vs 64 +/- 4.6 % of the area at risk of control hearts) and improved pressure recovery. Infarct-sparing effect of PAF was abolished by N-acetyl-L-cysteine and 5-hydroxydecanoate. Thus, the cardioprotective effect exerted by PAF-pretreatment involves activation of mK(ATP) channels and redox signaling in pre-ischemic phase.

Prognostic significance of high-risk HPV persistence after laser CO2 conization for high-grade CIN: a prospective clinical study

PURPOSE OF INVESTIGATION

To estimate the persistence rate of high-risk HPV DNA (HR-HPV DNA) in a population treated totally by laser CO2 conization for high-grade cervical intraepithelial neoplasia (HG-CIN), and to examine if this persistence might be considered an independent risk factor for relapsing disease.

METHODS

All women with a histological diagnosis of HG-CIN and planned for laser CO2 conization from January 2003 to December 2004 were prospectively submitted to a HR-HPV test prior to surgery and at three and six months of follow-up. Women providing written informed consent with 24 months of follow-up were enrolled in the study group. A positive HPV test, involvement of resection margins, age at first intercourse, smoking habits, parity and age at conization > 50 years old were considered as risk factors for relapsing HG-CIN during follow-up, and were univariately and multivariately analyzed to discover any independent influencing factors.

RESULTS

Of HG-CIN 15.4% resulted not to be HPV related nor relapsing. The HPV clearance rate after treatment was 78.8%. Involvement of resection margins and HR-HPV DNA persistence post-treatment resulted as the only two statistically significant risk factors for HG-CIN recurrence (rate 3.8%). HR-HPV DNA persistence in follow-up resulted to be independent from other risk factors at multivariate analysis.

CONCLUSIONS

Although able to reach a low recurrence rate of HG-CIN, laser CO2 conization does not remove HPV infection completely from the cervix with a case of persistence in every five treated patients. In our experience this persistence in itself represents an independent risk factor for developing relapsing disease and constitutes the basis to introduce HPV testing even in the follow-up of patients treated for HG-CIN by laser CO2 conization.

The paradigm of postconditioning to protect the heart

Ischaemic preconditioning limits the damage induced by subsequent ischaemia/reperfusion (I/R). However, preconditioning is of little practical use as the onset of an infarction is usually unpredictable. Recently, it has been shown that the heart can be protected against the extension of I/R injury if brief (10–30 sec.) coronary occlusions are performed just at the beginning of the reperfusion. This procedure has been called postconditioning (PostC). It can also be elicited at a distant organ, termed remote PostC, by intermittent pacing (dyssynchrony-induced PostC) and by pharmacological interventions, that is pharmacological PostC. In particular, brief applications of intermittent bradykinin or diazoxide at the beginning of reperfusion reproduce PostC protection. PostC reduces the reperfusion-induced injury, blunts oxidant-mediated damages and attenuates the local inflammatory response to reperfusion. PostC induces a reduction of infarct size, apoptosis, endothelial dysfunction and activation, neutrophil adherence and arrhythmias. Whether it reduces stunning is not clear yet. Similar to preconditioning, PostC triggers signalling pathways and activates effectors implicated in other cardioprotective manoeuvres. Adenosine and bradykinin are involved in PostC triggering. PostC triggers survival kinases (RISK), including A t and extracellular signal-regulated kinase (ERK). Nitric oxide, via nitric oxide synthase and non-enzymatic production, cyclic guanosine monophosphate (cGMP) and protein kinases G (PKG) participate in PostC. PostC-induced protection also involves an early redox-sensitive mechanism, and mitochondrial adenosine-5′ -triphosphate (ATP)-sensitive K⁺ and PKC activation. Protective pathways activated by PostC appear to converge on mitochondrial permeability transition pores, which are inhibited by acidosis and glycogen synthase kinase-3β (GSK-3β). In conclusion, the first minutes of reperfusion represent a window of opportunity for triggering the aforementioned mediators which will in concert lead to protection against reperfusion injury. Pharmacological PostC and possibly remote PostC may have a promising future in clinical scenario.

Nitric oxide and cardiac function

Nitric oxide (NO) participates in the control of contractility and heart rate, limits cardiac remodeling after an infarction and contributes to the protective effect of ischemic pre- and postconditioning. Low concentrations of NO, with production of small amounts of cGMP, inhibit phosphodiesterase III, thus preventing the hydrolysis of cAMP. The subsequent activation of a protein-kinase A causes the opening of sarcolemmal voltage-operated and sarcoplasmic ryanodin receptor Ca(2+) channels, thus increasing myocardial contractility. High concentrations of NO induce the production of larger amounts of cGMP which are responsible for a cardiodepression in response to an activation of protein kinase G (PKG) with blockade of sarcolemmal Ca(2+) channels. NO is also involved in reduced contractile response to adrenergic stimulation in heart failure. A reduction of heart rate is an evident effect of NO-synthase (NOS) inhibition. It is noteworthy that the direct effect of NOS inhibition can be altered if baroreceptors are stimulated by increases in blood pressure. Finally, NO can limit the deleterious effects of cardiac remodeling after myocardial infarction possibly via the cGMP pathway. The protective effect of NO is mainly mediated by the guanylyl cyclase-cGMP pathway resulting in activation of PKG with opening of mitochondrial ATP-sensitive potassium channels and inhibition of the mitochondrial permeability transition pores. NO acting on heart is produced by vascular and endocardial endothelial NOS, as well as neuronal and inducible synthases. In particular, while in the basal control of contractility, endothelial synthase has a predominant role, the inducible isoform is mainly responsible for the cardiodepression in septic shock.

[Colorectal carcinogenesis. 1. Hereditary predisposition and colorectal cancer]

Tumors arising sporadically represent 70-80% of colorectal cancer (CRC). The two best defined forms of inherited CRC-familial multiple polyposis (FMP) and Hereditary Non-Polyposis Colon Cancer (HNPCC) account respectively for<1% and 2-3% of CRC. These rare genetic syndromes (FMP, HNPCC, Peutz-Jeghers Syndrome) are caused by major predisposing gene mutations (APC gene, MMR gene, BMPR1A. SMAD4,...) and local environmental factors play only a minor role. In the sporadic forms of CRC, 25% have significant genetic predisposition probably related to alleles with weak penetration (APC*I1307K, TGFbR1*6Ala...) and are more strongly affected by environmental factors.

Plant-growth-promoting compounds produced by two agronomically important strains of Azospirillum brasilense, and implications for inoculant formulation

We evaluated phytohormone and polyamine biosynthesis, siderophore production, and phosphate solubilization in two strains (Cd and Az39) of Azospirillum brasilense used for inoculant formulation in Argentina during the last 20 years. Siderophore production and phosphate solubilization were evaluated in a chemically defined medium, with negative results. Indole 3-acetic acid (IAA), gibberellic acid (GA(3)), and abscisic acid (ABA) production were analyzed by gas chromatography-mass spectrometry. Ethylene, polyamine, and zeatin (Z) biosynthesis were determined by gas chromatography-flame ionization detector and high performance liquid chromatography (HPLC-fluorescence and -UV), respectively. Phytohormones IAA, Z, GA(3), ABA, ethylene, and growth regulators putrescine, spermine, spermidine, and cadaverine (CAD) were found in culture supernatant of both strains. IAA, Z, and GA(3) were found in all two strains; however, their levels were significantly higher (p < 0.01) in Cd (10.8, 2.32, 0.66 microg ml(-1)). ABA biosynthesis was significantly higher (p < 0.01) in Az39 (0.077 microg ml(-1)). Ethylene and polyamine CAD were found in all two strains, with highest production in Cd cultured in NFb plus L-methionine (3.94 ng ml(-1) h(-1)) and Az39 cultured in NFb plus L-lysine (36.55 ng ml(-1) h(-1)). This is the first report on the evaluation of important bioactive molecules in strains of A. brasilense as potentially capable of direct plant growth promotion or agronomic yield increase. Az39 and Cd showed differential capability to produce the five major phytohormones and CAD in chemically defined medium. This fact has important technological implications for inoculant formulation as different concentrations of growth regulators are produced by different strains or culture conditions.

Phytohormone production by three strains of Bradyrhizobium japonicum and possible physiological and technological implications

The aim of this work was to evaluate phytohormone biosynthesis, siderophores production, and phosphate solubilization in three strains (E109, USDA110, and SEMIA5080) of Bradyrhizobium japonicum, most commonly used for inoculation of soybean and nonlegumes in USA, Canada, and South America. Siderophore production and phosphate solubilization were evaluated in selective culture conditions, which had negative results. Indole-3-acetic acid (IAA), gibberellic acid (GA(3)), and abscisic acid (ABA) production were analyzed by gas chromatography-mass spectrometry (GC-MS). Ethylene and zeatin biosynthesis were determined by GS-flame ionization detection and high-performance liquid chromatography (HPLC-UV), respectively. IAA, zeatin, and GA(3) were found in all three strains; however, their levels were significantly higher (p < 0.01) in SEMIA5080 (3.8 microg ml(-1)), USDA110 (2.5 microg ml(-1)), and E109 (0.87 microg ml(-1)), respectively. ABA biosynthesis was detected only in USDA110 (0.019 microg ml(-1)). Ethylene was found in all three strains, with highest production rate (18.1 ng ml(-1) h(-1)) in E109 cultured in yeast extract mannitol medium plus L-methionine. This is the first report of IAA, GA(3), zeatin, ethylene, and ABA production by B. japonicum in pure cultures, using quantitative physicochemical methodology. The three strains have differential capability to produce the five major phytohormones and this fact may have an important technological implication for inoculant formulation.

Carcinogenèse colorectale

Gene alterations which have been implicated in colorectal carcinogenesis are characterized by three major mechanisms: chromosomal instability, microsatellite instability, and epigenetic mechanisms (i.e., CpG island hypermethylation). Progress in understanding of these genetic and epigenetic instabilities has led to advances in the individualization and characterization of more homogeneous sub-groups of colorectal tumors with regard to progression, prognosis and response to therapy.