Thoracic Duct Visualization in Esophageal Resection: A Pilot Trial

INTRODUCTION

Inadvertent thoracic duct injury is common during esophagectomy and may result in postoperative chylothorax. This study's objective was to investigate utility of patent blue injection as a modality for intraoperative thoracic duct visualization.

METHODS

A prospective, single-arm, interventional study of patients undergoing minimally invasive esophagectomy was performed. Patients were injected with patent blue dye into both groins prior to thoracic stage of surgery and assessed for duct visualization. Control group was formed by propensity score matching using retrospectively collected data regarding patients who underwent esophagectomy.

RESULTS

A total of 25 patients were included in analysis, compared to a control of 50 patients after matching. Thoracic duct was visualized in 60% of patients in the study group (15/25 patients). Significant differences were found between study and control groups (p < 0.05) with regards to median operative time (422 vs. 285 min, respectively), overall complications (16 vs. 34%, respectively), and median postoperative length of stay (13.5 vs. 10 days, respectively). There was a difference in rate of chyle leak between study and control groups; however, this was not significant (0 vs. 12%, respectively, p = 0.17).

CONCLUSION

Patent blue injection represents a simple method for thoracic duct visualization during minimally invasive esophagectomy which may improve surgical outcomes.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: Effects of postoperative fluids beyond the first 24 h

BACKGROUND AND OBJECTIVES

There are no guidelines for intravenous fluid (IVF) administration after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). This study assessed rates of post-CRS/HIPEC morbidity according to perioperative IVF administration.

METHODS

All patients undergoing CRS/HIPEC March 2007 to June 2018 were reviewed, recording clinicopathologic, operative, and postoperative variables. Patients were divided by peritoneal cancer index (PCI), comparing IVF volumes and types administered intraoperatively and during the first 72 h postoperatively. Optimal IVF rate cutoffs calculated using area under the receiver operating characteristic curves and Youden's index determined associations with complications.

RESULTS

Overall, 185 patients underwent CRS/HIPEC, and 81 (51%) had low PCI (<10) and 77 (49%) had high PCI (≥10). In low-PCI patients, high IVF rates on postoperative days (POD) #0-2 were associated with higher overall complications: POD#0 (46% vs. 89%, p = 0.001), POD#1 (40% vs. 86%, p < 0.05), and POD#2 (42% vs. 72%, p < 0.05). High IVF rates were associated with respiratory distress (7% vs. 26%, p = 0.02) on POD#0, ileus (14% vs. 47%, p = 0.007) and intensive care unit stay (11% vs. 33%, p = 0.022) on POD#1, and ICU stay (8% vs. 33%, p = 0.003) on POD#2.

CONCLUSIONS

For low PCI patients undergoing CRS/HIPEC, higher IVF rates were associated with postoperative complications. Post-CRS/HIPEC, IVF rates should be limited to prevent morbidity.

Actual and perceived gender differences in virtual tumor board participation

Introduction

Participant characteristics are known to affect group discourse and discussion outcomes. In medicine, many decisions are made by group consensus, therefore an understanding of these factors is highly relevant. We aimed to measure the effects of participant characteristics on tumor board discussions.

Methods

We performed a prospective, multi-institution, quantitative study of multi-disciplinary virtual tumor board meetings. Participant characteristics included age, gender, and clinical discipline. Outcomes of interest were speech events, duration, and discourse style. Participant impressions was assessed by a post-hoc survey.

Results

A total of 361 cases were discussed across 32 virtual meetings. Of the 283 attendees, 66.4 % were women, and all moderators were men. Women comprised 43 % of the 54 speakers, thus speaking less than male attendees (p < 0.001). No significant differences were detected in the duration or style of speech between men and women. Women participants commented more frequently on cases where the clinical attending was a woman (4.09 comments by women vs. 2.99 comments by men, p < 0.001), and less frequently when the attending was a man (2.48 comments by women vs. 3.20 comments by men, p < 0.001). On post hoc survey, men responded that they introduced ideas, guided discussions, and succeeded in influencing decisions significantly more than women reported that they did.

Conclusion

Women physicians were underrepresented in tumor boards as moderators, speakers, and attendings of record. Women physicians commented less on men physicians' patients. Women felt less impactful than their men counterparts, despite having the same duration and style of speech. Prompted participation, moderator feedback, talking points, and limiting the number of cases can be used to balance representation in discussions.

Excision of malignant and pre-malignant rectal lesions by transanal endoscopic microsurgery in patients under 50 years of age

BACKGROUND

The most common technique for treating benign and early malignant rectal lesions is transanal endoscopic microsurgery (TEM). Local excision is an acceptable technique for high-risk and elderly patients, but there are hardly any data regarding young patients.

AIM

To describe TEM outcomes in patients under 50 years of age.

METHODS

We collected demographic, clinical, and pathological data from all patients under the age of 50 years who underwent the TEM procedure at Hasharon Rabin Medical Center from January 2005 to December 2018.

RESULTS

During the study period, a total of 26 patients under the age of 50 years underwent TEM procedures. Their mean age was 43.3 years. Eleven (42.0%) were male. The mean operative time was 67 min, and the mean tumor size was 2.39 cm, with a mean anal verge distance of 8.50 cm. No major intraoperative or postoperative complications were recorded. The median length of stay was 2 d. Seven (26.9%) lesions were adenomas with low-grade dysplasia, four (15.4%) were high-grade dysplasia adenomas, two were T1 carcinomas (7.8%), and three were T2 carcinomas (11.5%). No residual disease was found following endoscopic polypectomy in two patients (7.8%), but four (15.4%) had other pathologies. Surgical margins were negative in all cases. Local recurrence was detected in one patient 33 mo following surgery.

CONCLUSION

Among young adult patients, TEM for benign rectal lesions has excellent outcomes. It may also offer a balance between the efficacy of complete oncologic resection and postoperative quality of life in the treatment of rectal cancer. In some cases, it may be considered an alternative to radical surgery.

The Effects of Primary Tumor Location on Survival after Liver Resection for Colorectal Liver Metastasis in the Mediterranean Population

(1) Background: There is an abundance of literature available on predictors of survival for patients with colorectal liver metastases (CRLM) but minimal information available on the relationship between the primary tumor location and CRLM survival. The studies that focus on the primary tumor location and CRLM survival exhibit a great deal of controversy and inconsistency with regard to their results (some studies show statistically significant connections between the primary tumor location and prognosis versus other studies that find no significant relationship between these two factors). Furthermore, the majority of these studies have been conducted in the West and have studied more diverse and heterogenous populations, which may be a contributing factor to the conflicting results. (2) Methods: We included patients who underwent liver resection for CRLM between December 2004 and January 2019 at two university-affiliated medical centers in Israel: Carmel Medical Center (Haifa) and Rabin Medical Center (Petach Tikvah). Primary tumors located from the cecum up to and including the splenic flexure were labeled as right-sided primary tumors, whereas tumors located from the splenic flexure down to the anal verge were labeled as left-sided primary tumors. (3) Results: We identified a total of 501 patients. Of these patients, 225 had right-sided primary tumors and 276 had left-sided primary tumors. Patients with right-sided tumors were significantly older at the time of liver surgery compared to those with left-sided tumors (66.1 + 12.7 vs. 62 + 13.1, p = 0.002). Patients with left-sided tumors had slightly better overall survival rates than those with right-sided tumors. However, the differences were not statistically significant (57 vs. 50 months, p = 0.37 after liver surgery). (4) Conclusions: The primary tumor location does not significantly affect patient survival after liver resection for colorectal liver metastasis in the Mediterranean population.

Major Postoperative Complications Limit Adjuvant Therapy Administration in Patients Undergoing Pancreatoduodenectomy for Distal Cholangiocarcinoma or Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Guidelines for perioperative systemic therapy administration in patients undergoing pancreatoduodenectomy for pancreatic adenocarcinoma (PDAC) and distal cholangiocarcinoma (dCCA) are evolving. Decisions regarding adjuvant therapy are influenced by postoperative morbidity, which is common after pancreatoduodenectomy. We evaluated whether postoperative complications are associated with receipt of adjuvant therapy after pancreatoduodenectomy.

METHODS

A retrospective analysis of patients undergoing pancreatoduodenectomy for PDAC or dCCA from 2015 to 2020 was conducted. Demographic, clinicopathologic, and postoperative variables were analyzed.

RESULTS

Overall, 186 patients were included-145 with PDAC and 41 with dCCA. Postoperative complication rates were similar for both pathologies (61% and 66% for PDAC and dCCA, respectively). Major postoperative complications (MPCs), defined as Clavien-Dindo >3, occurred in 15% and 24% of PDAC and dCCA patients, respectively. Patients with MPCs received lower rates of adjuvant therapy administration, irrespective of primary tumor (PDAC: 21 vs. 72%, p = 0.008; dCCA: 20 vs. 58%, p = 0.065). Recurrence-free survival (RFS) was worse for patients with PDAC who experienced an MPC [8 months (interquartile range [IQR] 1-15) vs. 23 months (IQR 19-27), p < 0.001] or who did not receive any perioperative systemic therapy [11 months (IQR 7-15) vs. 23 months (IQR 18-29), p = 0.038]. In patients with dCCA, 1-year RFS was worse for patients who did not receive adjuvant therapy (55 vs. 77%, p = 0.038).

CONCLUSION

Patients who underwent pancreatoduodenectomy for either PDAC or dCCA and who experienced an MPC had lower rates of adjuvant therapy and worse RFS, suggesting that clinicians adopt a standard neoadjuvant systemic therapy strategy in patients with PDAC. Our results propose a paradigm shift towards preoperative systemic therapy in patients with dCCA.

Short- and Long-Term Outcomes in Elderly Patients Following Hand-Assisted Laparoscopic Surgery for Colorectal Liver Metastasis

(1) Background: Hand-assisted laparoscopic surgery (HALS) has engendered growing attention as a safe procedure for the resection of metastatic liver disease. However, there is little data available regarding the outcomes of HALS for colorectal liver metastasis (CRLM) in patients over the age of 75. (2) Methods: We compare the short- and long-term outcomes of patients >75-years-old (defined in our study as "elderly patients" and referred to as group 1, G1), with patients <75-years-old (defined in our study as "younger patients" and referred to as group 2, G2). (3) Results: Of 145 patients, 28 were in G1 and 117 were in G2. The most common site of the primary tumor was the right colon in G1, and the left colon in G2 (p = 0.05). More patients in G1 underwent laparoscopic anterior segment resection compared with G2 (43% vs. 39% respectively) (p = 0.003). 53% of patients in G1 and 74% of patients in G2 completed neoadjuvant therapy (p = 0.04). The median size of the largest metastasis was 32 (IQR 19-52) mm in G1 and 20 (IQR 13-35) mm in G2 (p = 0.001). The rate of complications (Dindo-Clavien grade ≥ III) was slightly higher in G1 (p = 0.06). The overall 5-year survival was 30% in G1 and 52% in G2 (p = 0.12). (4) Conclusions: Hand-assisted laparoscopic surgery for colorectal liver metastasis is safe and effective in an elderly patient population.

Perineural Invasion of Pancreatic Ductal Adenocarcinoma is Associated with Early Recurrence after Neoadjuvant Therapy Followed by Resection

BACKGROUND

Neoadjuvant therapy (NAT) is increasingly utilized in the treatment of pancreatic ductal adenocarcinoma (PDAC). However, there are limited data on risk factors and patterns of recurrence after surgical resection. This study aimed to analyze timing and recurrence patterns of PDAC after NAT followed by curative resection.

METHODS

The medical charts of patients with PDAC treated with NAT followed by curative-intent surgical resection at a single health system from January 1, 2012 to January 1, 2020 were retrospectively reviewed. Early recurrence was defined as recurrence within 12 months of surgical resection.

RESULTS

91 patients were included and median follow up was 20.1 months. Recurrence occurred in 50 (55%) patients, with median recurrence free survival (RFS) of 11.9 months. Overall, 18 (36%) patients had local and 32 (64%) had distant recurrences. Median RFS and overall survival (OS) between local and distant recurrence were similar. Perineural invasion (PNI) and the presence of a T2 + tumor was significantly higher in recurrence group than in no recurrence group. PNI was a significant risk factor for early recurrence.

CONCLUSION

After NAT and surgical resection of PDAC, disease recurrence was common, with distant metastasis being the most common. PNI was significantly higher in the recurrence group.

T1 Gastric Cancer is Associated With a High Incidence of Regional Lymph Node Metastases

INTRODUCTION

Early stage gastric cancer, particularly T1 disease, is associated with high recurrence-free and overall survival rates following resection with curative intent. However, rare cases of T1 gastric cancer have nodal metastasis and this is associated with poor outcomes.

METHODS

Data from gastric cancer patients treated with surgical resection and D2 lymph node (LN) dissection at a single tertiary care institution from 2010 to 2020 were analyzed. Patients with early stage (T1) tumors were assessed in detail to identify variables associated with regional LN metastasis including histologic differentiation, signet ring cells, demographics, smoking history, neoadjuvant therapy, and clinical staging by endoscopic ultrasound (EUS). We used standard statistical techniques including Mann-Whitney U and Chi-squared tests.

RESULTS

Of 426 patients undergoing surgery for gastric cancer, 34% (n = 146) were diagnosed with T1 disease on surgical pathology. Among 146 T1 (T1a, T1b) gastric cancers, 24 patients [(17%) T1a (n = 4), T1b (n = 20)] had histologically confirmed regional LN metastases. The age at diagnosis ranged between 19 and 91 y and 54.8% were male. Prior smoking status was not associated with nodal positivity (P = 0.650). Of the 24 patients with positive LN on final pathology, seven patients received neoadjuvant chemotherapy. EUS was performed on 98 (67%) of the 146 T1 patients. Of these patients, 12 (13.2%) had positive LN on final pathology; however, none (0/12) were detected on preoperative EUS. There was no association between node status on EUS and node status on final pathology (P = 0.113). The sensitivity of EUS for N status was 0%, specificity was 84.4%, negative predictive value was 82.2% and positive predictive value was 0%. Signet ring cells were identified in 42% of node negative T1 tumors and 64% of node positive T1 tumors (P = 0.063). For LN positive cases on surgical pathology, 37.5% had poor differentiation, 42% had lymphovascular invasion, and regional nodal metastases were associated with increasing T stage (P = 0.003).

CONCLUSIONS

T1 gastric cancer is associated with a substantial risk (17%) of regional LN metastasis, when pathologically staged following surgical resection and D2 lymphadenectomy. Clinically staged N+ disease by EUS was not significantly associated with pathologically staged N+ disease in these patients.

Preoperative frailty to predict short-term outcomes in patients with cancer

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Background: Frailty is associated with increased postoperative complications. Despite multiple evidence-based modalities to assess frailty, surgeons often make subjective assessments of patients’ ability to tolerate surgery. Identification of those at risk of poor outcomes is particularly important in Surgical Oncology, as major resections may worsen debility and functional status, limiting the patients' ability to receive further therapy. The Risk Analysis Index (RAI-C) is a validated tool to assess frailty in surgical patients. It assigns points for any cancer diagnosis, potentially overestimating frailty in Surgical Oncology patients, and has not been validated in this subgroup. Methods: We performed a prospective, surgeon-blinded study to correlate results of a preoperatively administered frailty survey to predict short- and long-term outcomes in patients with histologically proven malignancy who underwent surgery. The RAI-C, Patient Health Questionnaire (PHQ9), and General Anxiety Disorder (GAD) surveys were administered to assess for frailty, depression, and anxiety, respectively; C-reactive protein (CRP), pre-albumin, albumin, and hematocrit were obtained. Outcomes, including readmission, major complications, ICU admission, disposition (home vs rehabilitation/nursing facility), and 1-year survival were compared between the different groups as defined by survey and lab results. Results: One hundred ninety-one patients were included, of which 135 patients were considered frail based on the predefined value (RAI-C ≥21). Frail patients were more likely to be readmitted within 30 days (14% vs 2%, P=0.01). No difference was found in length of stay, 90-day readmission, ICU admission, major complications, or disposition. Only 15.8% of patients met criteria for anxiety and 11% met criteria for depression. Measured outcomes were similar in patients defined as anxious or depressed. Patients with abnormal pre-albumin levels were more likely to require ICU admissions (31% vs 8%, P <0.005), postoperative intubation (12% vs 0.02%, P=0.02), and to be discharged to a facility other than home (19% vs 10%, P=0.01). Similar trends were noted for patients with abnormal albumin levels who also had longer lengths of stay (mean 9.32 vs 7.88 days, P=0.007). There was an association of improved 1-year survival in patients with normal CRP, pre-albumin, albumin, and hematocrit levels. Frailty as determined by RAI-C survey was not associated with decreased 1-year survival. Conclusions: The RAI-C is a validated tool that can be used for prescreening of Surgical Oncology patients at risk of postoperative readmission, however the score did not correlate with other important outcomes including major morbidity, discharge disposition, and 1-year survival. Results from the survey, as well as preoperative laboratory results can be used in screening patients who may benefit from preoperative optimization and increased follow-up.

Effects of doxorubicin and ibrutinib on atrial arrhythmogenity: ex-vivo assessment in human myocardium

Introduction

The cytostatic drugs doxorubicin (Dox) and ibrutinib (Ibr) are established in the treatment of various tumor diseases. In (pre-) clinical studies, both chemotherapeutic agents showed cardiotoxic side effects, including atrial fibrillation [1]. In this context, patients with limited cardiac performance or diabetes might be particularly vulnerable, as these pre-existing conditions represent independent risk factors for cardiac complications [2].

Objectives

The dose-dependency of acute pro-arrhythmogenic effects of Dox and Ibr on the contractile activity of human atrial muscle tissue was investigated.

Patients and methods

Atrial samples were taken intraoperatively during cardiac procedures. Functional muscle strips were prepared from the cardiac trabeculae, followed by incubation with different concentrations of Dox or Ibr for 30 minutes. Subsequently, functional measurements were performed. Isometric contraction force and arrhythmogenic occurrences were recorded. The samples were consecutively exposed to external stressors during measurement (Fig. 1).

We evaluated the overall occurrence of arrhythmogenic contractions and during which phase of the protocol they occurred. The latter was expressed as degree of arrhythmogenesis (Fig. 1).

Following the functional measurements, the muscle strips were conserved at −80°C.

Results

We isolated 127 muscle strips from 29 patients. Highest rates of overall arrhythmic contractions were observed at 10μM Dox and 0.5μM Ibr (77.8 & 100% vs. 58.4% (control)). Mean degree of arrhythmogenesis increased from 1.63 (control) to 2.17 (10μM Dox) and 3.11 (0.5μM Ibr).

Analyzing our data according to the included individuals, treatment with Dox and Ibr enhanced the degree of arrhythmogenesis in the majority of patients. (Fig. 2)

Conclusion

Our protocol is suitable for investigating drug related acute pro-arrhythmogenic effects on human atrial myocardium. Treatment of isolated atrial myocardium with Dox and Ibr enhanced its susceptibility to arrhythmogenic occurrences. Optimal pro-arrhythmogenic conditions were observed at 10μM Dox and 0.5μM Ibr. The treated samples showed higher overall rates of arrhythmogenic contractions and the arrhythmogenic activity occurred earlier within our protocol.

Outlook

We will correlate the experimentally obtained data with clinical patient data, such as LVEF, BMI and diabetic status. The conserved muscle strips will be analyzed using standardized assays comparing post-translational modification (e.g. phosphorylation and oxidation) of key regulators of excitation contraction coupling (e.g. PKA, CaMKII, Ca2+ channels).

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): DZHK (German Centre for Cardiovascular Research), partner site Berlin

Surgical management of pancreatic cancer liver oligometastases

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer, which commonly metastasizes to the liver. The current standard of care for metastatic PDAC is systemic chemotherapy, however there are limited emerging data regarding surgical resection of pancreatic oligometastases in select patients. Here we review the literature addressing resection of PDAC liver oligometastases.

Gallbladder Cancer: A Single-Institution 10-Year Experience-Analysis of Adenocarcinoma Subtypes and Tumors Arising from Intracholecystic Papillary Neoplasms

BACKGROUND

Gallbladder cancer accounts for 1.2% of global cancer diagnoses. Literature on biliary-type adenocarcinoma (BTA), and specifically carcinoma arising from intracholecystic papillary-tubular neoplasms (ICPNs), is limited. This study describes a retrospective, single-institution experience with gallbladder cancer, focusing on histological subtypes and prognosis.

METHODS

A retrospective review was performed of patients who underwent cholecystectomy for a malignant neoplasm of the gallbladder between 2007 and 2017. Demographic, clinicopathologic, and operative variables, as well as survival outcomes, were analyzed.

RESULTS

From a total of 145 patients, BTAs were most common (93, 64%). Compared with non-BTAs, BTAs were diagnosed at a lower American Joint Committee on Cancer stage (p = 0.045) and demonstrated longer median recurrence-free survival (38 vs. 16 months, p = 0.014; median follow-up 36 months). Tumors arising from ICPNs (18, 12%) were more commonly associated with BTA (14 cases). Compared with BTAs not associated with ICPNs (29 patients), associated cases demonstrated lower pathologic stage (p = 0.006) and lower rates of liver and perineural invasion (0% vs. 49% and 14% vs. 48%, respectively; p < 0.05). Cumulative 5-year survival probability was higher for patients with gallbladder neoplasm of any subtype associated with ICPNs compared with those that were not associated with ICPNs (54% vs. 41%, p = 0.019; median follow-up 23 months). This difference was also significant when comparing BTAs associated with ICPNs and non-associated cases (63% vs. 52%, p = 0.005).

CONCLUSIONS

This study demonstrated unique pathological and prognostic features of BTAs and of carcinomas arising from ICPNs. Histopathological variance may implicate prognosis and may be used to better guide clinical decision making in the treatment of these patients.

Hand-Assisted Laparoscopic Surgery Is Superior to Open Liver Resection for Colorectal Liver Metastases in the Posterosuperior Segments

Introduction: Laparoscopic liver resections (LLR) of colorectal metastasis located in posterosuperior segments (1, 4A, 7 and 8) are challenging and highly demanding. The aim of our study is to determine the safety and feasibility of hand-assisted laparoscopic surgery (HALS) in the resections of the posterosuperior lesions and to compare the peri-operative, short-term and long-term outcomes with the open liver resection (OLR) approach.

Methods and Results: A retrospective study of patients who underwent either HALS or OLR for metastatic colorectal cancer (mCRC) located in the posterosuperior segments of the liver between 2008 and 2018 in two university affiliated medical centers.

Results: A total of 187 patients were identified, of whom 78 underwent HALS and 109 underwent OLR. There was no difference between the HALS and OLR with regard to preoperative factors (age, primary CRC tumor location, number and anatomical distribution of liver metastasis, pre-operative neo-adjuvant treatment, operative time, blood transfusion rate, and resection margins positivity). On the other hand, HALS compared to OLR had a significantly shorter mean hospital stay (4 vs. 6 days; P = 0.003), and a lower total complications rate (25 vs. 47% P = 0.006). Both groups had no 30-day mortality. Also, patients who underwent HALS vs. OLR had similar liver metastases recurrence (55 vs. 51%. P = 0.65) and 5-year survival (47 vs. 45%. P = 0.72).

Conclusions: HALS for mCRC located in posterosuperior liver segments is safe and feasible and it is a preferable approach due to its lower complication rate and shorter hospital stay while not compromising survival and disease recurrence.

Revue exhaustive de la littérature sur le bon usage des AINS, dont l’ibuprofène, en période de Covid-19

Introduction

Le GRAINS, groupe de réflexion sur les AINS, est composé d’experts pluridisciplinaire hospitalier et de ville qui regroupe plusieurs médecins spécialistes. Il s’est constitué en vue de réfléchir sur le bon usage des anti-inflammatoires non-stéroïdiens (AINS) dans le contexte de la pandémie de COVID-19, et est soutenu par GlaxoSmithKline Santé Grand Public. Les travaux effectués par le GRAINS ont été publiés dans une revue de littérature exhaustive. L’objectif du GRAINS est d’avoir une discussion ouverte sur l’utilisation des AINS dans la gestion de la douleur dans le contexte de la COVID-19 et des infections en général, considérant les progrès réalisés dans la production de connaissances et les preuves de la littérature scientifique.

Matériels et méthodes

Ce groupe pluridisciplinaire d’experts constitué de rhumatologues, infectiologues, pédiatre, médecin généraliste, pharmacologue et pharmaciens, a pointé l’inquiétude et le manque d’informations énoncés par les patients à leur pharmacien. Les experts du GRAINS se sont réunis au travers de différentes assemblées et se sont accordés sur la nécessité de mettre à disposition des professionnels de santé une information synthétique de la littérature scientifique et des outils pour vulgariser cette information pour le grand public. La revue de littérature réalisée par les experts du GRAINS porte sur plus de 40 études internationales récentes concernant l’utilisation des AINS dans un contexte de la COVID-19.

Résultats

Le recours aux anti-inflammatoires non stéroïdiens (AINS) en général, et à l’ibuprofène en particulier, n’expose pas à un risque accru de la Covid-19 ni à des formes grave de cette infection.

Discussion

Encourager la discussion sur le bon usage des AINS en automédication. Les experts pointent l’inquiétude et le manque d’information énoncés par les patients à leur pharmacien. Par leur action ils souhaitent alerter sur les risques liés au surdosage d’alternatives aux AINS en particulier dans le traitement de la fièvre et de la douleur. Ils encouragent à ne pas se priver davantage de l’arsenal thérapeutique des AINS et militent pour une utilisation raisonnée de ces traitements.

Conclusion

Il n’existe actuellement aucune preuve scientifique établissant un lien entre l’ibuprofène et l’aggravation de l’infection due au SARS-CoV-2.

Sarcopenia as a Predictor of Survival in Patients with Pancreatic Adenocarcinoma After Pancreatectomy

OBJECTIVE

To determine whether sarcopenia can potentially predict worse survival after resection of pancreatic ductal adenocarcinoma.

BACKGROUND

Sarcopenia is correlated with poor outcomes in hepatopancreatobiliary malignancies, but the relationship of both its qualitative and quantitative features with patient survival after pancreatectomy has not been investigated in a western population.

PATIENTS AND METHODS

Preoperative cross-sectional computed tomography scans of consecutive patients who underwent pancreatectomy in 2005-2017 were evaluated for skeletal muscle index (SMI), intramuscular adipose tissue content (IMAC), and visceral-to-subcutaneous adipose tissue area ratio (VSR). Sex-specific categorical cut-offs were determined. Findings were correlated with outcome.

RESULTS

The study included 111 patients, 47% of whom were female, with a median age of 67 years (range: 35-87 years), and median body mass index of 23 kg/m² (range: 16-40 kg/m²); 77% had a Whipple procedure and 66% received adjuvant chemotherapy. Low SMI correlated with poor overall survival (OS) (P = 0.007), disease-specific survival (DSS) (P = 0.006), and recurrence-free survival (RFS) (P = 0.01). High IMAC correlated with poor OS (P = 0.04). Patients with high IMAC tended to have a shorter DSS (P = 0.09), with no correlation with RFS (P = 0.6). VSR was not associated with survival. Multivariable analysis yielded an independent association of low SMI with OS (HR = 1.7, 95%CI: 1.1-2.8, P = 0.02), DSS (HR = 1.8, 95%CI: 1.03-3.2, P = 0.04), and RFS (HR = 1.8, 95%CI: 1.1-2.8, P = 0.01), and of high IMAC with OS (HR = 1.9, 95%CI: 1.1-3.1, P = 0.01).

CONCLUSION

Both qualitative and quantitative measures of skeletal muscle were independently associated with impaired survival in patients with resectable PDAC. Sarcopenia might serve as an early radiographic surrogate of aggressive tumor behavior, with potential implications for clinical decision-making and future study.

Robotic-assisted Heller Myotomy Is a Safe Operation

BACKGROUND

Surgical myotomy is the best therapeutic option for patients with achalasia. The minimally invasive technique is considered to be the preferred method for many surgeons. Robotic-assisted laparoscopic myotomy has several advantages over conventional laparoscopic surgery. These benefits include more accurate incisions that may result in a lower rate of intra-operative complications.

OBJECTIVES

To describe our technique of performing robotic-assisted Heller myotomy and to review the initial results of this procedure.

METHODS

All patients undergoing robotic-assisted Heller myotomy for achalasia between the years 2012-2018 at Rabin Medical Center were retrospectively reviewed from our institutional prospective database.

RESULTS

Thirty patients underwent robotic-assisted Heller myotomy for achalasia. Mean operative time was 77 minutes (range 47-109 minutes) including docking time of the robotic system. There were no cases of conversion to laparoscopic or open surgery. There were no cases of intra-operative perforation of the mucosa. None of the patients had postoperative morbidity or mortality. Good postoperative results were achieved in 25 patients. Four patients required additional intervention (3 had endoscopic dilatations and 1 with known preoperative endstage achalasia had undergone esophagectomy). One patient was lost to follow-up.

CONCLUSIONS

Robotic-assisted Heller myotomy is a safe technique with a low incidence of intra-operative esophageal perforation compared to the laparoscopic approach. We believe that robotic-assisted surgery should be the procedure of choice to treat achalasia.

Transanal endoscopic microsurgery under spinal anaesthesia

Background

Transanal endoscopic microsurgery (TEM) is considered the procedure of choice for rectal adenomas non-amendable for endoscopic excision and for early rectal cancer. TEM may gain more importance in patients who are considered unfit for major surgery. The option of spinal anaesthesia may offer many advantages for patients undergoing TEM while maintaining the principles of complete tumour excision. The aim of this study is to report the outcome of patients undergoing TEM under spinal anaesthesia.

Methods

Demographic and clinical data pertaining patients undergoing TEM under spinal anaesthesia between 2004 and 2015 were retrospectively collected.

Results

A total of 158 TEM procedures were recorded in the study period. Twenty-three patients (15%) underwent the procedure under spinal anaesthesia and were included in the study; 13 of them were male and ten were female. The mean age of the patients was 69.1 ± 10.6 years. Seventeen (74%) rectal lesions were adenomas, two (9%) were adenocarcinoma and four (17%) had involved margins after polypectomy. The mean tumour size was 2.1 cm (range, 0.5-3). Distance from the anal verge was 7.7 ± 2.2 cm. Seventeen (74%) lesions were in the posterior wall. The operative time was 73 min (range, 46-108) No adverse anaesthesia-related events were recorded, and the post-operative pain was reduced. The median time of hospitalisation was 2 days (range, 1-4). No major complications were noted, and the minor complications were treated conservatively. The surgical margins were free of tumour in all cases.

Conclusion

TEM under spinal anaesthesia had short duration of surgery, no increase in operative and post-operative complications or hospital length of stay. Avoiding the use of general anaesthesia, in such challenging procedure, may open new opportunities for patients determined to be unfit for general anaesthesia.

Intermolecular dynamics of NH3-rare gas complexes in the ν2 umbrella region of NH3 investigated by rovibrational laser jet-cooled spectroscopy and ab initio calculations

High resolution jet-cooled spectroscopy experiments have been realized to investigate the intermolecular dynamics of van der Waals (vdW) heterodimers between NH₃ and rare gas (Rg) atoms in the ν₂ umbrella mode region of NH₃. With respect to a previous study dedicated to NH₃-Ar [Asselin et al. Mol. Phys. 116, 3642 (2018)], the sensitivity and spectral resolution of our laser spectrometer coupled to a pulsed supersonic jet have been significantly improved to derive more accurate excited state spectroscopic parameters from rovibrational analyses. In addition, we calculated the ground and ν₂ excited vibration-rotation-tunneling (VRT) states of these complexes on the four-dimensional ab initio potential energy surfaces from Loreau et al. [J. Chem. Phys. 141, 224303 (2014), ibid. 143, 184303 (2015).] Transition frequencies and intensities of the allowed ν₂ = 1 ← 0 transitions obtained from the calculated energy levels and wave functions agree well with the experimental data and are helpful in their analysis. By means of a pseudodiatomic model with the assumption of weak Coriolis coupling, the rovibrational analysis of both the Π_e/f(j = 1,k = 0) ←Σ_f(j = 0,k = 0) and Σ_f(j = 1,k = 0) ←Σ_f(j = 0,k = 0) transitions in ortho NH₃-Rg (Rg = Ne, Ar, Kr, Xe) complexes enabled us to determine reliable excited state parameters and derive accurate values of the effective vdW bond length R_eff, force constant k_s, and vdW stretching frequency ν_s. Comparison between the experimental structural parameters and those from the ab initio calculated VRT levels shows good agreement for NH₃-Ne, NH₃-Ar and NH₃-Kr, and a similar variation of R_eff, k_s, and ν_s with the polarizability of Rg in the ground and ν₂ excited states. Anomalously small values of ν_s and k_s derived for NH₃-Xe in the Π_e/f(j = 1,k = 0) state suggest that the applied model is not valid in this case, due to the presence of another state coupling to the perturbed Π_f state. Such a state could not be found, however.

Neutrophil-to-Lymphocyte Ratio Predicts Recurrence Pattern in Patients with Resectable Colorectal Liver Metastases

BACKGROUND

Studies have suggested that neutrophil-to-lymphocyte ratio (NLR) has value as a predictor of long-term outcomes in various cancer types. Its prognostic potential in patients with CRLM has not been thoroughly investigated. This original, retrospective study assessed the relationship between the preoperative NLR, survival outcomes, and recurrence patterns in patients after colorectal liver metastasis resection (CRLM).

METHODS

The prospectively maintained database of a tertiary medical center was queried for all patients who underwent CRLM resection between 2005 and 2017. Patients were divided into two groups: NLR <3 (normal) or >3 (high). Recurrence risk was analysed using Fine and Gray correction for competing risk method and cause specific analyses.

RESULTS

The cohort included 231 patients of whom 53 (23%) had a high neutrophil-to-lymphocyte ratio. At presentation, 35% had synchronous disease and 48% had a solitary metastasis; median tumor size was 2 cm. Patients with a high NLR had a significantly higher rate of simultaneous colorectal resection (P = 0.01). A high NLR was independently associated with worse OS (P = 0.02), worse DFS (P = 0.03), and higher risk of recurrence (P = 0.048), specifically recurrence with an extrahepatic pattern (P = 0.03).

CONCLUSIONS

A high preoperative NLR was independently associated with poorer survival outcomes and extrahepatic recurrence pattern. The NLR appears to have prognostic importance in CRLM and may serve as a surrogate marker of aggressive systemic disease after resection. These findings warrant external validation, preferably in a prospective design.

Hand-assisted Laparoscopic Surgery for Colorectal Liver Metastasis: Analysis of Short-term and Long-term Results

BACKGROUND

There is scant data regarding the outcomes of hand-assisted laparoscopic surgery (HALS) for colorectal liver metastasis (CRLM). The aim of this study is to report our experience and analyze the short-term and long-term results.

MATERIALS AND METHODS

Retrospective study of patients undergoing HALS for CRLM in 2 university affiliated medical centers.

RESULTS

Two hundred and thirty-eight liver procedures were performed on 145 patients including 205 parenchymal sparing resections and 33 anatomic resections. The median number of metastases was 1 (range: 1 to 8), 38 patients (26.2%) had 3 or more metastases, and 41 patients (28.3 had a bi-lobar disease. The tumor size was 20 (2 to 90) mm, and 52 patients (36.6%) had a tumor larger than 30 mm. Nighty-nine patients (67.8%) received neoadjuvant chemotherapy. In 8 patients (5.5%) the laparoscopic liver resection was combined with ablation, and 16 patients (11%) underwent a synchronous resection of colorectal cancer. The median operative time, blood loss during surgery, and postoperative hospital stay were 163 minutes, 300 mL, and 4 days, respectively. The median modified Iwate complexity score was 4 (0 to 10) and the conversion rate to open surgery was 5.5%. The overall and major complication rates were 23.8% and 3.6%, respectively. The mortality rate was 0.7%. R0 resections were achieved in 91% of patients. Median overall survival for all the cohort (intend to treat) was 59 months, and the 8- and 10-year overall survival rates were 47.3% and 24.9%, respectively.

CONCLUSIONS

This study shows that HALS is a safe and efficacious treatment for selected patients with CRLM.

Paediatric community-acquired bacteraemia, pneumococcal invasive disease and antibiotic resistance fell after the pneumococcal conjugate vaccine was introduced

AIM

This study examined the impact of the routine pneumococcal conjugate vaccination (PCV) on childhood community-acquired bacteraemia (CAB) and antibiotic resistance patterns in Israeli children.

METHODS

Israel added the PCV vaccine to its national immunisation programme in July 2009. We retrospectively analysed the medical records of all patients with CAB under 18 years at three children's hospitals in Tel Aviv and Jerusalem from 2007 to 2015. The microbiological data, clinical presentation, pneumococcal serotype distribution, antibiotic susceptibility and outcomes of infections were compared before and after the vaccine was introduced.

RESULTS

There were 511 904 emergency department visits and 125 922 children were hospitalised. Of those, 238 had CAB before vaccination was introduced (mean age 17 months) and 316 had CAB after the introduction (mean age 21 months). Emergency department presentations for CAB fell from 141.8 to 91.8 per 100 000 visits: a relative risk reduction (RRR) of 35%. Hospitalisations for CAB decreased from 430 to 337 per 100 000 admissions: an RRR of 22%. Hospitalisations due to Staphylococcus aureus increased significantly and penicillin nonsusceptible blood Streptococcus pneumoniae isolates decreased significantly.

CONCLUSION

Introducing national pneumococcal conjugate vaccination significantly changed the epidemiology of CAB, with reduced antibiotic-resistant Streptococcus pneumoniae and increased hospitalisation rates for Staphylococcus aureus infections.

Correlation Between Intraoperative and Pathological Findings for Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

This study aimed to examine the correlation between intraoperative and pathological findings for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) and to determine their prognostic significance.

METHODS

Pathological reports of all colorectal cancer (CRC) patients undergoing CRS/HIPEC between 2009 and 2016 were retrospectively reviewed. Pathological specimens lacking tumor cells were defined as negative pathological specimens (NPS). The intraoperative peritoneal cancer index (PCI) and pathological PCI (excluding NPS) were calculated separately. Receiver operating characteristic (ROC) curves were applied to compare the prognostic value of intraoperative and pathological scoring systems.

RESULTS

For 108 CRC patients, 113 CRS/HIPEC procedures were performed. Of 959 pathological specimens examined, 178 (18.6%) were NPS. Overall, 78 procedures (69%) showed NPS. In 52 procedures (46%), the pathological PCI differed from the intraoperative PCI (∆PCI > 0). The ROC areas for intraoperative PCI and pathological PCI were similar in predicting 1-year overall survival (OS), 2-year OS, and 1-year disease-free survival (all p values not significant). However, for the patients with NPS, the number of positive specimens (containing tumor tissue) was superior to intraoperative PCI in predicting 2-year OS (ROC under the curve areas, 0.69 vs. 0.58, respectively; p = 0.012). In addition, a subgroup of 15 patients with a high ∆PCI (≥ 3) had a more favorable median OS than a matched group of 30 patients with similar intraoperative PCI and a ∆PCI of 0 (median survival not reached vs. 21.6 months, respectively; p = 0.05).

CONCLUSIONS

In the majority of CRC CRS/HIPEC procedures, NPS may be found. Among patients with NPS, pathological correlation may have a prognostic significance.

The Antiaggregating Activity of Clopidogrel Is due to a Metabolic Activation by the Hepatic Cytochrome P450-1A

Clopidogrel and ticlopidine are two well known selective anti-ADP agents which are inactive in vitro and must be administered in vivo to fully exhibit their antiaggregating and antithrombotic effects. Since previous studies have clearly demonstrated that the activation steps take place in the liver, we examined the effect of specific induction or inhibition of cytochrome P450 subfamilies on the antiaggregating activity of clopidogrel. SKF 525-A, a global cytochrome P450 inhibitor, dramatically decreased the antiaggregating effect of clopidogrel, therefore indicating that cytochrome P450 enzymes are involved in the hepatic activation of clopidogrel. The efficacy of clopidogrel was increased in animals pretreated with 3-methylcholanthrene and (3-naphthoflavone, indicating that the cytochrome P450-1A subfamily pathway was mainly involved in the activating metabolism of clopidogrel. The use of specific antibodies directed against the various cytochrome P450 subfamilies ascertained this observation.

Colonoscopy after the first episode of acute diverticulitis: challenging management paradigms

BACKGROUND

Colonoscopy is commonly recommended after the first episode of acute diverticulitis to exclude colorectal neoplasia. Recent data have challenged this paradigm due to insufficient diagnostic yield. The aim of this study was to assess whether colonoscopy after the first episode of acute diverticulitis is needed to exclude colorectal neoplasia.

METHODS

We performed a retrospective cohort analysis of medical records of patients admitted for the first episode of acute diverticulitis between January 2008 and December 2012. Ambulatory colonoscopy was routinely recommended at discharge. Clinical follow-up and telephone surveys were used for data collection.

RESULTS

Four hundred and twenty-five patients with a mean age of 62.6 years (range 21-98 years) were admitted during the 5-year period. Three hundred and ten (72.9 %) patients underwent colonoscopy at median time of 3.2 months after discharge. Five patients (1.6 %) of the 310 available for evaluation had malignant findings in colonoscopy. Of those, one patient had rectal carcinoma away from the inflamed site and one had colonic lymphoma. None of the 95 patients <50 years of age was found to have adenocarcinoma of the colon.

CONCLUSIONS

Cancer is rarely detected in colonoscopy following the first episode of acute diverticulitis. These results question this indication for colonoscopy, especially in patients under 50.

From organelle to organ: ZRIZI MATE-Type transporter is an organelle transporter that enhances organ initiation

Plant architecture is a predictable but flexible trait. The timing and position of organ initiation from the shoot apical meristem (SAM) contribute to the final plant form. While much progress has been made recently in understanding how the site of leaf initiation is determined, the mechanism underlying the temporal interval between leaf primordia is still largely unknown. The Arabidopsis ZRIZI (ZRZ) gene belongs to a large gene family encoding multidrug and toxic compound extrusion (MATE) transporters. Unique among plant MATE transporters identified so far, ZRZ is localized to the membrane of a small organelle, possibly the mitochondria. Plants overexpressing ZRZ in initiating leaves are short, produce leaves much faster than wild-type plants and show enhanced growth of axillary buds. These results suggest that ZRZ is involved in communicating a leaf-borne signal that determines the rate of organ initiation.

Stage-specific regulation of Solanum lycopersicum leaf maturation by class 1 KNOTTED1-LIKE HOMEOBOX proteins

Class 1 KNOTTED1-LIKE HOMEOBOX (KNOXI) genes encode transcription factors that are expressed in the shoot apical meristem (SAM) and are essential for SAM maintenance. In some species with compound leaves, including tomato (Solanum lycopersicum), KNOXI genes are also expressed during leaf development and affect leaf morphology. To dissect the role of KNOXI proteins in leaf patterning, we expressed in tomato leaves a fusion of the tomato KNOXI gene Tkn2 with a sequence encoding a repressor domain, expected to repress common targets of tomato KNOXI proteins. This resulted in the formation of small, narrow, and simple leaves due to accelerated differentiation. Overexpression of the wild-type form of Tkn1 or Tkn2 in young leaves also resulted in narrow and simple leaves, but in this case, leaf development was blocked at the initiation stage. Expression of Tkn1 or Tkn2 during a series of spatial and temporal windows in leaf development identified leaf initiation and primary morphogenesis as specific developmental contexts at which the tomato leaf is responsive to KNOXI activity. Arabidopsis thaliana leaves responded to overexpression of Arabidopsis or tomato KNOXI genes during the morphogenetic stage but were largely insensitive to their overexpression during leaf initiation. These results imply that KNOXI proteins act at specific stages within the compound-leaf development program to delay maturation and enable leaflet formation, rather than set the compound leaf route.

The NAC-domain transcription factor GOBLET specifies leaflet boundaries in compound tomato leaves

Leaves are formed at the flanks of the shoot apical meristem (SAM) and develop into a variety of forms. In tomato, prolonged leaf patterning enables the elaboration of compound leaves by reiterative initiation of leaflets with lobed margins. In goblet (gob) loss-of-function mutants, primary leaflets are often fused, secondary leaflets and marginal serrations are absent, and SAMs often terminate precociously. We show that GOB encodes a NAC-domain transcription factor expressed in narrow stripes at the leaf margins, flanking the distal side of future leaflet primordia, and at the boundaries between the SAM and leaf primordia. Leaf-specific overexpression of the microRNA miR164, a negative regulator of GOB-like genes, also leads to loss of secondary-leaflet initiation and to smooth leaflet margins. Plants carrying a dominant gob allele with an intact ORF but disrupted miR164 binding site produce more cotyledons and floral organs, have split SAMs and, surprisingly, simpler leaves. Overexpression of a form of GOB with an altered miR164 binding site in leaf primordia leads to delayed leaflet maturation, frequent, improperly timed and spaced initiation events, and a simple mature leaflet form owing to secondary-leaflet fusion. miR164 also affects leaflet separation in Cardamine hirsuta, a Brassicaceae species with complex leaves. Genetic and molecular analyses suggest that GOB expression is intact in the simplified leaves of entire tomato mutants, which have a defect in a putative repressor of auxin responses. Our results show that GOB marks leaflet boundaries and that its accurate spatial, temporal and quantitative activity affects leaf elaboration in a context-dependent manner.

Specific role of LeMAN2 in the control of seed germination exposed by overexpression of the LeMAN3 gene in tomato plants

Endo-beta-mannanase is one of the key enzymes involved in the hydrolysis of the mannan-rich cell walls of tomato (Solanum lycopersicon) seeds. Two isoforms of endo-beta-mannanase have been characterized in tomato seeds: LeMAN2 is active in the micropylar area prior to germination and LeMAN1 is active after germination in all endosperm cells surrounding the cotyledons. To explore whether general mannanase activity in the endosperm cap is sufficient to promote germination, the gene encoding LeMAN3 was inserted into transgenic tomato plants under the control of a CaMV-35S promoter. Expression of LeMAN3 was evident in the endosperm cap and in the lateral endosperm of the transgenic seeds 10 min after imbibition. An activity test indicated increased activity of endo-beta-mannanase in the transgenic lines relative to the control line in all seed parts, during the first 20 h of imbibition. However, overexpression of LeMAN3 in transgenic seeds inhibited seed germination at both optimal and suboptimal temperatures. Detailed RT-PCR analyses revealed the transcription patterns of the genes encoding the various mannanase isoforms, and indicated a delay in LeMAN2 transcription in the endosperm cap of the transgenic seeds. Interestingly, tissue-print assays indicated similar mannanase activity in the micropylar areas for both transgenic and control seeds. These results indicate that overexpression of active endo-beta-mannanase in the endosperm cap is not sufficient to enable hydrolysis of the cell walls or to promote germination of tomato seeds. Cell-wall hydrolysis in these endosperm cells is under tight control and requires the specific activity of LeMAN2.

Ethylene glycol and amino acid derivatives of 5-aminolevulinic acid as new photosensitizing precursors of protoporphyrin IX in cells

Protoporphyrin IX (PpIX) is used as a photosensitizing agent in photodynamic detection and therapy (PDT) of cancer and is synthesized intracellularly from aminolevulinic acid (ALA) precursors. To evaluate means to specifically target ALA derivatives to defined cells, we have synthesized and characterized ethylene glycol esters and amino acid pseudodipeptide derivatives of ALA as potential specific substrates for cellular esterases and aminopeptidases, respectively. The PpIX formation induced by these products was investigated using cultures of human and rat cell lines of carcinoma and endothelial origins. The cytotoxicity of these compounds in the absence of light was also controlled. The results have shown that ethylenglycol esters can induce high levels of PpIX and are useful at concentrations below their cytotoxicity threshold. From the ALA-amino acid derivatives which were evaluated, the highest PpIX production was obtained using ALA derivatives of neutral amino acids, as compared to acidic or basic amino acids.

Very slow chiral inversion of clopidogrel in rats: a pharmacokinetic and mechanistic investigation

Clopidogrel hydrogen sulfate, a thienopyridine derivative, is an ADP receptor antagonist that inhibits platelet aggregation. Clopidogrel is an enantiopure carboxylic ester of S-configuration. The R-enantiomer is devoid of antithrombotic activity and can provoke convulsions at high doses in animals. During preclinical safety evaluation, the possible chiral inversion of clopidogrel has, therefore, been investigated in vivo after repeated oral administration of different dose levels of clopidogrel to male and female rats. Due to rapid metabolism in the liver and low plasma levels of unchanged drug, possible chiral inversion was assessed by monitoring the plasma concentrations of the carboxylic acid metabolites, i.e., the (S)- and (R)-acid, by means of a stereoselective assay. The production of 4 to 8% of (R)-acid was observed. This could be the result of chiral inversion of either clopidogrel or its main metabolite, the (S)-acid. Thus, the possibility of nonenzymatic and enzymatic inversion of clopidogrel and its carboxylic acid metabolite was studied in vitro by chiral HPLC and (1)H NMR. Nonenzymatic chiral inversion of clopidogrel at 37 degrees C in 0.1 M phosphate buffers could be observed but was found to be slow, with estimated half-lives of 7 to 12 days, depending on the pH. The (S)-acid was configurationally fully stable up to 45 days in phosphate buffers. Neither clopidogrel nor its carboxylic acid metabolites were subject to enzymatic chiral inversion in isolated rat hepatocyte suspensions. We conclude that the nonenzymatic inversion of clopidogrel accounts for the 4 to 8% of chiral inversion seen in vivo in the rat.

Expression and induction of CYP1A1/1A2, CYP2A6 and CYP3A4 in primary cultures of human hepatocytes: a 10-year follow-up

1. The aims were to refine experimental conditions (using 76 human hepatocyte preparations) in terms of the selection of enzyme inducers and their optimal concentration, the treatment duration with inducers and the choice of specific cytochrome P450 isoform(s) probes to optimize the use of primary hepatocytes for predicting the potential induction by new chemical entities of cytochrome P450 isoforms in vivo in man. 2. In the absence of any inducer, basal cytochrome P450 isoform(s)-mediated activities decreased to 20% of their initial activity (end of the seeding period) by 72-96 h. In contrast, UGT-dependent enzyme activities remained at a constant level (+/- 20%) up to the fifth day of culture. 3. Beta-naphthoflavone, at an optimal concentration of 50 microM and after a 3-day treatment, specifically and potently induced 7-ethoxyresorufin (10.4 +/- 10.4-fold, n = 74) and phenacetin (6.6 +/- 6.4-fold, n = 60) O-deethylation processes, markers for CYP1A1 and CYP1A2 isoforms respectively. Only a 2-fold increase was noted following treatment with 2 mM phenobarbitone, whereas dexamethasone and rifampicin had no effect at all. 4. A 3-day treatment of human hepatocytes with 50 microM dexamethasone was associated with a major induction of both coumarin 7-hydroxylation (9.4 +/- 11.4-fold, n = 49) and nifedipine dehydrogenation (4.7 +/- 3.8-fold, n = 61), markers for CYP2A6 and CYP3A4 respectively. Phenobarbitone, however, exhibited a broad but moderate inducing effect on 7-ethoxyresorufin (2.2 +/- 1.5-fold, n = 55) and phenacetin (1.7 +/- 0.9-fold, n = 54) O-deethylation, coumarin 7-hydroxylation (3.9 +/- 9.2-fold, n = 50) and nifedipine dehydrogenation (2.1 +/- 2.0-fold, n = 47). 5. Km obtained for the different cytochrome P450 isoform substrates in untreated hepatocytes were in the same range of magnitude that those determined on human hepatic microsomal fractions. Enzyme induction processes were characterized by a large increase in apparent Vmax whereas apparent Km were not affected. 6. These studies demonstrate that human hepatocytes in primary culture can respond specifically and quantitatively to model inducers. This in vitro system offers a useful approach to study the regulation of human hepatic biotransformation activities and should facilitate the demand for a reproducible method for addressing cytochrome P450 induction.

Disposition of irbesartan, an angiotensin II AT1-receptor antagonist, in mice, rats, rabbits, and macaques

Metabolism and disposition of irbesartan, an angiotensin II AT(1) receptor antagonist, were investigated in mice, rats, rabbits, and macaques. In both rats and macaques, irbesartan was characterized by a rapid oral absorption, a large volume of distribution, a low plasma clearance, and a long terminal half-life. The oral bioavailability in macaques was notably higher than in rats. Irbesartan was highly protein bound in rats and macaques. A lower binding rate was found in mice and rabbits. In distribution studies performed in rats, mice, and rabbits, irbesartan was rapidly distributed into most organs and tissues including brain, intrauterine area, and milk. No retention of radioactivity in tissues other than liver and kidney was noted. Irbesartan was the main circulating compound in rats, rabbits, and macaques representing a maximum of 67, 68, and 80% of plasma radioactivity, respectively. The drug was metabolized mainly by glucuronidation (primarily on the tetrazole ring), hydroxylation, and additional oxidation. The overall pathways within the different species generated 18 metabolites identified from bile, urine, and feces samples. Irbesartan did not significantly induce or inhibit most of the isoenzymes commonly associated with drug metabolism in either rats or macaques after oral administration for 1 month. In most species irbesartan and its metabolites were mainly excreted in feces with more than 80% of a radioactive dose recovered within 24 or 48 h. Enterohepatic circulation was demonstrated in rats and macaques.

Disposition of tiludronate (Skelid) in animals

The disposition of tiludronate in mouse, rat, rabbit, dog and monkey has been studied after oral and intravenous doses. Like other bisphosphonates, tiludronate was characterized by poor absorption from the gastrointestinal tract. Peak plasma concentrations appeared shortly (0.5-1 h) after dosing, except for the baboon (4.5 h). Food intake highly impaired intestinal absorption The affinity of tiludronate for bone and the slow release from this deep compartment could account for the large volume of distribution and the low plasma clearance found in all species. Tiludronate has low affinity for red blood cells and binds moderately to serum proteins, mainly to serum albumin. Calcified tissues appeared to be the main target for deposition. Distribution into bone was not homogenous, with higher levels in the trabecular bone than in the corticol part of the long bones. The uptake of tiludronate into bone was unequivocally less in the older animal. No metabolism occurred in the tested animal species. The major route of elimination of the absorbed drug is urine. Preclinical observations made with tiludronate, like with other bisphosphonates, were predictive of results obtained in clinical investigation.

[Recording nocturnal erections following injuries and insurance claims: cost-effectiveness]

Road accidents, work accidents, or other trauma can cause impotence and are frequently followed by insurance claims. During 1990-97 we examined 230 males with such a complaint. All underwent full polysomnographic recordings in the sleep laboratory for 2 nights, during the course of which NPT (nocturnal penile tumescence) was examined with special equipment. It was assessed by an experienced technician following planned awakenings from REM sleep. In 75 of the 230 subjects (33%), satisfactory erections were observed. In 100 (43%), who experienced at least 3 periods of REM sleep, no erections occurred. These patients were categorized as suffering from organic impotence. In the remaining 55 (24%), the results were inconclusive, with only partial erections or not enough REM sleep periods. Since a man recognized as suffering from impotence may be awarded large monthly payments for life, these examinations, in our opinion, are an important tool to prevent unjustified claims, and can save the state unnecessary expenses.

Role of cytochrome P-4502C9 in irbesartan oxidation by human liver microsomes

The oxidative metabolism of irbesartan, a new nonpeptide angiotensin II receptor antagonist, was investigated on 12 human fully characterized hepatic microsomes and purified cytochrome P-450 (CYP) isoforms. After incubation of microsomes with irbesartan and NADPH, four main hydroxy metabolites were formed, as confirmed by liquid chromatography-mass spectrometry analysis. Irbesartan oxidation follows Michaelis-Menten kinetics, consistent with the involvement of a single CYP isoform in these hydroxylation processes. Only a low interindividual variability (2-fold difference) was observed in drug oxidation, even in preparations lacking CYP2D6. Km and Vmax for irbesartan oxidation were 54 +/- 6.5 microM and 0.62 +/- 0.18 nmol/min/mg, respectively. Irbesartan oxidation correlated (r2 = 0. 769) with tolbutamide (CYP2C9 substrate) 4-methyl-hydroxylation. Oxidation of irbesartan was markedly inhibited by sulfaphenazole (CYP2C9 inhibitor), but not by any of several other CYP inhibitors. In the same manner, both tolbutamide and warfarin (CYP2C9 substrates), were competitive-type inhibitors of irbesartan oxidation with Ki values of 500 and 30 microM, respectively. Moreover, irbesartan was a competitive-type inhibitor of tolbutamide 4-methylhydroxylation (Ki = 317 microM). Nifedipine also potentially decreased irbesartan oxidation, whereas neither ketoconazole and triacetyloleandomycin (CYP3A inhibitors), nor diltiazem and verapamil, (CYP3A4 substrates), exhibited an inhibitory effect. Additional studies demonstrated that nifedipine was an inhibitor of irbesartan (Ki = 20 microM) and tolbutamide oxidation processes, whereas irbesartan had no effect at all on nifedipine dehydrogenation. Enzyme kinetics suggest that nifedipine is a noncompetitive-type inhibitor of CYP2C9-mediated catalytic activities. Finally, only microsomes containing recombinant human liver CYP2C9 were capable of oxidizing irbesartan. These results provide evidence that CYP2C9 plays a major role in irbesartan oxidation.

Prolonged elimination half-life of phenol after dermal exposure

BACKGROUND

Phenol is a general protoplastic poison which has been in use in medicine and industry for decades. It is readily absorbed through the skin causing both local and systemic toxicity.

CASE REPORT

A 47-year-old male had 90% phenol spilled over his left foot and shoe (3% of body surface area). After a 4 1/2-hour exposure, manifestations included confusion, vertigo, faintness, hypotension, ventricular premature beats, atrial fibrillation, dark-green urine, and tense swelling, blue-black discoloration, hypalgesia, and hypoesthesia of the affected area. Treatment consisted of irrigation with copious amounts of water, incisions, and supportive measures.

RESULTS

Peak serum phenol was 21.6 micrograms/mL, considered in the fatal range. Peak urine phenol plus urine-conjugated phenol was 13,416 mg/g creatinine, indicating a major absorption. Elimination half-life was 13.86 hours, considerably longer than previously reported.

CONCLUSIONS

Prolonged skin contact with concentrated phenol in an occlusive environment may result in a major absorption and a long elimination half-life even if the area involved is small. Prolonged elimination may be explained by extensive tissue distribution or by "slow-release reservoir" properties of the skin. Such exposure may be associated with severe systemic and local toxicities. Immediate removal from exposure and aggressive decontamination of the skin are essential to reduce these risks.

Correlation between oral drug absorption in humans, and apparent drug permeability in TC-7 cells, a human epithelial intestinal cell line: comparison with the parental Caco-2 cell line

PURPOSE

To determine and compare the relationship between in vivo oral absorption in humans and the apparent permeability coefficients (Papp) obtained in vitro on two human intestinal epithelial cell lines, the parental Caco-2 and the TC-7 clone.

METHODS

Both cell lines were grown for 5-35 days on tissue culture-treated inserts. Cell monolayers were analysed for their morphology by transmission electron micrography, and for their integrity with respect to transepithelial electrical resistance, mannitol and PEG-4000 transport, and cyclosporin efflux. Papp were determined for 20 compounds exhibiting large differences in chemical structure, molecular weight, transport mechanisms, and percentage of absorption in humans.

RESULTS

The TC-7 clone exhibits morphological characteristics similar to those of the parental Caco-2 cell line, concerning apical brush border, microvilli, tight junctions and polarisation of the cell line. The TC-7 clone however appeared more homogenous in terms of cell size. Both cell lines achieved a similar monolayer integrity towards mannitol and PEG-4000. Monolayer integrity was achieved earlier for the TC-7 clone, mainly due to its shorter doubling time, i.e. 26 versus 30 hours for parental Caco-2 cells. When using cyclosporin A as a P-glycoprotein substrate, active efflux was lower in the TC-7 clone than in the parental Caco-2 cells. The Papp and mechanisms of transport (paracellular or transcellular routes, passive diffusion and active transport) were determined for 20 drugs. A relationship was established between the in vivo oral absorption in humans and Papp values, allowing to determine a threshold value for Papp of 2 10(-6) cm/sec, above for which a 100% oral absorption could be expected in humans. Both correlation curves obtained with the two cell types, were almost completely superimposable. These studies also confirmed that the dipeptide transporter is underexpressed in both cell lines.

CONCLUSIONS

On the basis of morphological parameters, biochemical activity and drug transport characteristics, the TC-7 clone appeared to be a valuable alternative to the use of parental Caco-2 cells for drug absorption studies.

Cytochrome P450 isoform inhibitors as a tool for the investigation of metabolic reactions catalyzed by human liver microsomes

Cytochrome P450 chemical inhibitors are widely used to define the role of individual cytochrome P450 isozyme(s) in a metabolism process. In this study, cytochrome P450 isoform-dependent reactions were investigated on our human liver microsomes bank (n = 34) and characterized for both KM and VMAX values (n > or = 3). These metabolic reactions were: 7-ethoxyresorufin O-deethylation (CYP1A1), phenacetin O-deethylation (CYP1A2), coumarin 7-hydroxylation (CYP2A6), tolbutamide 4-methylhydroxylation (CYP2C9), dextromethorphan O-demethylation (CYP2D6), aniline 4-hydroxylation (CYP2E1) and nifedipine dehydrogenation (CYP3A4). Literature data-based specific inhibitors were selected and characterized for both their inhibitory constant (Ki) and the inhibition-type toward their specific substrate. Results were as follows: alpha-naphthoflavone (CYP1A1; mixed-type interaction with a Ki = 0.01 microM), furafylline (CYP1A2; competitive-type interaction with a Ki = 3 microM when microsomes were incubated with both furafylline and phenacetin; noncompetitive-type interaction with a Ki = 0.6 microM when microsomes were preincubated with furafylline and NADPH), pilocarpine (CYP2A6; competitive-type interaction with a Ki = 4 microM), sulfaphenazole (CYP2C9; competitive-type interaction with a Ki = 0.3 microM), quinidine (CYP2D6; competitive-type interaction with a Ki = 0.4 microM, diallyldisulfide (CYP2E1; noncompetitive-type interaction with a Ki = 150 microM on an aniline concentration range of 10-60 microM; competitive-type interaction with a Ki = 100 microM on an aniline concentration range of 80-2000 microM) and ketoconazole (CYP3A4; mixed-type interaction with a Ki = 0.015 microM). Once the inhibitors' potency was determined, the selective effects of these inhibitors were evaluated after incubation of human hepatic microsomes with isoform-selective substrates in the presence of the different chemical inhibitors. Up to 10 times the Ki value toward the isoform-selective probe, pilocarpine, sulfaphenazole, quinidine and ketoconazole exhibited potent inhibitory and specific effects. alpha-Naphthoflavone and furafylline both inhibited phenacetin and 7-ethoxyresorufin O-deethylation processes, a consequence of the absence of CYP1A1 in noninduced human liver. Diallyldisulfide exhibited broad and nonspecific inhibitory effects. When used in their "window of selectivity," ie., up to 10-fold the Ki value, most chemical inhibitors powerfully and specifically inhibited cytochrome P450 isoform-specific reactions when analyzed at their KM values.

Outcomes and obstacles of urodynamics

Urodynamic testing provides information on bladder function and bladder outlet and sphincteric competence. The author explains when patients should be referred and provides some insight into these tests.

The human intestinal epithelial cell line Caco-2; pharmacological and pharmacokinetic applications

The gastrointestinal tract remains the most popular and acceptable route of administration for drugs. It offers the great advantage of convenience and many compounds are well absorbed and thereby provide acceptable plasma concentration-time profiles. Currently there is considerable interest from the pharmaceutical industry in development of cell culture systems that would mimic the intestinal mucosa in order to evaluate strategies for investigating and/or enhancing drug absorption. The intestinal epithelial cells of primary interest, from the standpoint of drug absorption and metabolism, are the villus cells, which are fully differentiated cells. An in vitro cell culture system consisting of a monolayer of viable, polarized and fully differentiated villus cells, similar to that found in the small intestine, would be a valuable tool in the study of drug and nutrient transport and metabolism. The Caco-2 cell line, which exhibits a well-differentiated brush border on the apical surface and tight junctions, and expresses typical small-intestinal microvillus hydrolases and nutrient transporters, has proven to be the most popular in vitro model (a) to rapidly assess the cellular permeability of potential drug candidates, (b) to elucidate pathways of drug transport (e.g., passive versus carrier mediated), (c) to assess formulation strategies designed to enhance membrane permeability, (d) to determine the optimal physicochemical characteristics for passive diffusion of drugs, and (e) to assess potential toxic effects of drug candidates or formulation components on this biological barrier. Since differentiated Caco-2 cells express various cytochrome P450 isoforms and phase II enzymes such as UDP-glucuronosyltransferases, sulfotransferases and glutathione-S-transferases, this model could also allow the study of presystemic drug metabolism.

In vitro N-glucuronidation of SB 47436 (BMS 186295), a new AT1 nonpeptide angiotensin II receptor antagonist, by rat, monkey and human hepatic microsomal fractions

The glucuronidation of the AT1 nonpeptide angiotensin II receptor antagonist, SR 47436 (BMS 186295), was investigated in hepatic microsomes prepared from various species, i.e., Sprague-Dawley rat, Cynomolgus monkey and Caucasian humans. The drug was found to undergo N-glucuronidation on the tetrazole moiety as confirmed by its hydrolysis by beta-glucuronidase, its associated radioactivity when UDP-[U-14C]glucuronic acid was used as substrate and by different techniques such as high-performance liquid chromatography-mass spectrometry and nuclear magnetic resonance. Glucuronide formation was optimal at pH 5.0 along with a "0.2 mg of Brij 58 per mg of protein" ratio, regardless of the investigated species. Cynomolgus monkey microsomes glucuronidated SR 47436 (BMS 186295) to the greatest extent, with a relative catalytic efficiency 11.0- and 2.6-fold higher than that observed in rat and human, respectively. SR 47436 (BMS 186295) glucuronidation followed Michaelis-Menten kinetics. Bilirubin:UDP-glucuronosyltransferase isoform was not involved, inasmuch as bilirubin did not affect its glucuronidation, 7,7,7-triphenylheptanoic acid was a noncompetitive inhibitor and glucuronidation was only decreased 2-fold in Gunn rats. SR 47436 (BMS 186295) glucuronidation was enhanced markedly after treatment of rats with dexamethasone (Vmax/Km = 71.5 vs. 2.6 in untreated animals). Among the drugs used which undergo phenolic, carboxylic acid, alcohol or tertiary amine glucuronidation, only monodigitoxigenin-monodigitoxoside, flurbiprofen, naproxen, testosterone and estrone inhibited SR 47436 (BMS 186295) glucoronidation in a noncompetitive manner. These data suggest that SR 47436 (BMS 186295) was glucuronidated by a highly dexamethasone-inducible UDP-glucuronosyltransferase isoform(s), different from that involved in the glucuronidation of monodigitoxigenin-monodigitoxoside.

The antiaggregating activity of clopidogrel is due to a metabolic activation by the hepatic cytochrome P450-1A

Clopidogrel and ticlopidine are two well known selective anti-ADP agents which are inactive in vitro and must be administered in vivo to fully exhibit their antiaggregating and antithrombotic effects. Since previous studies have clearly demonstrated that the activation steps take place in the liver, we examined the effect of specific induction or inhibition of cytochrome P450 subfamilies on the antiaggregating activity of clopidogrel. SKF 525-A, a global cytochrome P450 inhibitor, dramatically decreased the antiaggregating effect of clopidogrel, therefore indicating that cytochrome P450 enzymes are involved in the hepatic activation of clopidogrel. The efficacy of clopidogrel was increased in animals pretreated with 3-methylcholanthrene and beta-naphthoflavone, indicating that the cytochrome P450-1A subfamily pathway was mainly involved in the activating metabolism of clopidogrel. The use of specific antibodies directed against the various cytochrome P450 subfamilies ascertained this observation.