The role of intraoperative swab during appendectomy in patients with uncomplicated and complicated appendicitis

INTRODUCTION

Bacteria play an important role not only in pathogenesis of appendicitis but also in the postoperative course of patients. However, the usefulness of an intraoperative swab during appendectomy is controversial. The primary aim of this study was to investigate the impact of intraoperative swab during appendectomy on the postoperative outcome in patients with uncomplicated and complicated appendicitis.

METHODS

A retrospective analysis was conducted on a consecutive series of 1570 adult patients who underwent appendectomy for acute appendicitis at the University Hospital Erlangen between 2010 and 2020. Data regarding the intraoperative swab were collected and analyzed for the entire cohort as well as for patients with uncomplicated and complicated appendicitis.

RESULTS

An intraoperative swab was taken in 29% of the cohort. The bacterial isolation rate in the obtained intraoperative swabs was 51%, with a significantly higher rate observed in patients with complicated appendicitis compared to those with uncomplicated appendicitis (79% vs. 35%, p < 0.001). The presence of a positive swab was significantly associated with worse postoperative outcomes, including higher morbidity, increased need for re-surgery, and longer hospital stay, when compared to patients without a swab or with a negative swab. A positive swab was an independent risk factor for postoperative morbidity (OR 9.9 (95% CI 1.2-81.9), p = 0.034) and the need for adjustment of postoperative antibiotic therapy (OR 8.8 (95% CI 1.1-72.5), p = 0.043). However, a positive swab resulted in postoperative antibiotic therapy adjustment in only 8% of the patients with bacterial isolation in the swab.

CONCLUSION

The analysis of swab samples obtained during appendectomy for acute appendicitis can help identify patients at a higher risk of a worse postoperative outcome. However, the frequency of antibiotic regime changes based on the swab analysis is low.

A contemporary assessment of total neoadjuvant therapy (TNT) protocols for locally advanced rectal cancer: adoption and expert perspectives at German Cancer Society (DKG)-certified colorectal cancer centers

PURPOSE

The treatment paradigm for locally advanced rectal cancer (LARC) is shifting toward the total neoadjuvant therapy (TNT) concept, which administered systemic chemotherapy in the neoadjuvant setting, either before or after chemoradiotherapy (CRT) or short-course radiotherapy (SCRT). First results have shown higher pathologic complete response (pCR) rates and a favorable impact on disease-free survival (DFS). Our study aimed to evaluate the current clinical practice and expert opinion regarding TNT for locally advanced rectal cancer across DKG (German Cancer Society)-certified colorectal cancer centers.

METHODS

A comprehensive online questionnaire, constituted of 14 TNT-focused queries targeting patients with locally advanced rectal cancer, was conducted among DKG-certified colorectal cancer centers registered within the database of the Addz (Arbeitsgemeinschaft Deutscher Darmzentren) between December 2022 and January 2023.

RESULTS

A significant majority (68%) indicated that they treated between 0 and 10 patients using a TNT protocol. Only a third (36%) of these centers participated in patient enrollment for a TNT study. Despite this, 84% of centers reported treating patients in a manner analogous to a TNT study, with the RAPIDO regimen being the most prevalent approach, employed by 60% of the respondents. The decision to adopt a TNT approach was primarily influenced by factors, such as the lower third of the rectum (93% of centers), cT4 stage (86% of centers), and a positive circumferential resection margin (80% of centers). Regarding concerns, 65% of the survey respondents expressed no reservations about the TNT concept, while 35% had concerns. In particular, there appears to be disagreement and uncertainty in regard to a clinical complete response and the "Watch and Wait" approach. While some centers adopt the watch-and-wait approach (42%), others only utilize it when extirpation is otherwise necessary (39%), and a portion still proceeds with surgery as initially planned (19%). The survey also addressed unmet needs, which were elaborated in the free-text responses. Overall, there was high interest in participating in planned observational studies.

CONCLUSIONS

This study presents an overview of current clinical practice and unmet needs within DKG-certified German colorectal cancer centers. It is noteworthy that total neoadjuvant therapy (TNT) is predominantly performed outside of clinical trials. Moreover, across the centers, there is significant heterogeneity in handling clinical complete response and adopting the "watch and wait" approach. Further research is needed to establish standardization in the care of locally advanced rectal cancer.

Myostatin is associated with the presence and development of acute-on-chronic liver failure

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) has been linked to different pathophysiological mechanisms, including systemic inflammation and mitochondrial dysfunction. Sarcopenia has also been proposed as a potential mechanism; myostatin is a key factor inducing sarcopenia. Therefore, this study aimed to evaluate the association of myostatin levels with the development of ACLF and mortality in patients with cirrhosis.

METHODS

We performed a prospective cohort study, including both outpatient and hospitalized patients with cirrhosis. Clinical, biochemical, and nutritional parameters were evaluated, and the development of acute decompensation (AD) or ACLF during follow-up was recorded. ACLF was defined according to the EASL-CLIF criteria. Receiver-operating characteristic, Kaplan-Meier and Cox regression analyses were performed.

RESULTS

A total of 186 patients with the whole spectrum of cirrhosis were included; mean age was 53.4 ± 14 years, mean Child-Pugh score was 8 ± 2.5 and mean MELD score was 15 ± 8. There was a stepwise decrease in myostatin levels from a compensated stage to AD and ACLF. Myostatin correlated positively with nutritional markers and negatively with severity scores. The prevalence of sarcopenia was 73.6%. During follow-up, 27.9% of patients developed AD and 25.8% developed ACLF. Most episodes were grade 2-3, mainly (62.5%) precipitated by infections. The most common organ failures observed were in the liver (63.3%) and the kidney (64.6%). Receiver-operating characteristic analysis yielded <1,280 pg/ml as the best serum myostatin cut-off for the prediction of ACLF. In Kaplan-Meier curves and multivariate analysis, myostatin levels remained independently associated with the incidence of ACLF and survival.

CONCLUSIONS

There is a progressive decrease in myostatin levels as cirrhosis progresses, demonstrating an association of sarcopenia with the development of ACLF and increased mortality.

IMPACT AND IMPLICATIONS

Myostatin is a muscle hormone, it is decreased in patients with muscle loss and is a marker of impaired muscle function. In this study we show that myostatin levels are decreased in patients with cirrhosis, with lower levels in patients with acute decompensation and acute-on chronic liver failure (ACLF). Low myostatin levels in cirrhosis predict the development of ACLF and mortality independently of liver disease severity and sex.

Risk Factors for Conversion from Laparoscopic to Open Appendectomy

(1) Background: Since its introduction in the 1990s, laparoscopic appendectomy has become established over the years and is today considered the standard therapy for acute appendicitis. In some cases, however, a conversion to the open approach is still necessary. The primary aim of this study was to identify risk factors for the need to convert from the laparoscopic to an open approach during appendectomy for acute appendicitis. (2) Methods: A retrospective analysis of 1220 adult patients who underwent laparoscopic appendectomy for acute appendicitis from 2010 to 2020 at the University Hospital Erlangen was performed. Data, including patient demographics and pre-, intra-, and postoperative findings, were collected and compared between patients with and without conversion. (3) Results: The conversion rate in our cohort was 5.5%. A higher preoperative WBC count and CRP (OR 1.9, p = 0.042, and OR 2.3, p = 0.019, respectively), as well as the presence of intraoperative perforation, necrosis or gangrene, perityphlitic abscess and peritonitis (OR 3.2, p = 0.001; OR 2.3, p = 0.023; OR 2.6, p = 0.006 and OR 2.0, p = 0.025, respectively) were identified as independent risk factors for conversion from the laparoscopic to the open approach. Conversion was again independently associated with higher morbidity (OR 2.2, p = 0.043). (4) Conclusion: The laparoscopic approach is feasible and safe in the majority of patients with acute appendicitis. Only increased inflammatory blood markers could be detected as the preoperative risk factors potentially influencing the choice of surgical approach but only with low specificity and sensitivity. For the decision to convert, intraoperative findings are additionally crucial. However, patients with conversion should receive special attention in the postoperative course, as these have an increased risk of developing complications.

Risk factors for postoperative morbidity, prolonged length of stay and hospital readmission after appendectomy for acute appendicitis

PURPOSE

The aim of the present study was to identify risk factors associated with postoperative morbidity and major morbidity, with a prolonged length of hospital stay and with the need of readmission in patients undergoing appendectomy due to acute appendicitis.

METHODS

We performed a retrospective analysis of 1638 adult patients who underwent emergency appendectomy for preoperatively suspected acute appendicitis from 2010 to 2020 at the University Hospital Erlangen. Data including patient demographics, pre-, intra-, and postoperative findings were collected and compared between different outcome groups (morbidity, major morbidity, prolonged length of postoperative hospital stay (LOS) and readmission) from those patients with verified acute appendicitis (n = 1570).

RESULTS

Rate of negative appendectomies was 4%. In patients with verified acute appendicitis, morbidity, major morbidity and readmission occurred in 6%, 3% and 2%, respectively. Mean LOS was 3.9 days. Independent risk factors for morbidity were higher age, higher preoperative WBC-count and CRP, lower preoperative hemoglobin, longer time to surgery and longer duration of surgery. As independent risk factors for major morbidity could be identified higher age, higher preoperative CRP, lower preoperative hemoglobin and longer time to surgery. Eight parameters were independent risk factors for a prolonged LOS: higher age, higher preoperative WBC-count and CRP, lower preoperative hemoglobin, need for conversion, longer surgery duration, presence of intraoperative complicated appendicitis and of postoperative morbidity. Presence of malignancy and higher preoperative WBC-count were independent risk factors for readmission.

CONCLUSION

Among patients undergoing appendectomy for acute appendicitis, there are relevant risk factors predicting postoperative complications, prolonged hospital stays and readmission. Patients with the presence of the identified risk factors should receive special attention in the postoperative course and may benefit from a more individualized therapy.

Preoperative risk assessment for postoperative pancreatic fistula (POPF): Image-based calculation of duct-to-parenchyma (D/P) ratio and an Alignment of Duct and Mucosa (ADAM) anastomosis may lead to a low POPF rate—results from 386 patients

Background

Postoperative pancreatic fistula (POPF) is the most critical complication after pancreatoduodenectomy (PD). Preoperative identification of high-risk patients and optimal pancreatic reconstruction technique can be a way to reduce postoperative complications.

Methods

A series of 386 patients underwent PD over a 10-year period (2009–2019). On routinely performed preoperative computed tomography (CT) images, the ventro-dorsal diameters of duct (D) and parenchyma (P) were measured in the cutting plane at the superior mesenteric vein. Then, the ratio of both values was calculated (D/P ratio) Double-layer pancreatojejunostomy with alignment of duct and mucosa (ADAM) by two monofilament threads (MFT) was performed in 359 patients and pancreatogastrostomy (PG) in 27 patients. The incidence of POPF was diagnosed according to the International Study Group for Pancreatic Fistula criteria.

Results

The overall rate of POPF was 21% (n = 80), and the rate of clinically relevant type B/C fistulas 6.5% (n = 25). A D/P ratio of &lt;0.2 was significantly associated with type B/C fistula (11%, p &lt; 0.01). In low-risk patients (D/P ratio &gt;0.2), type B/C fistula occurred only in 2%, and in high-risk patients (D/P ratio &lt;0.2) in 9%. ADAM anastomosis was performed safely by two different surgeons. A PG anastomosis had double-digit POPF rates in all groups.

Conclusion

Preoperative CT imaging with D/P measurement may predict the risk of POPF development. A cut off D/P ratio of &lt;0.2 was significantly associated with clinical relevant POPF. ADAM anastomosis may be an option for pancreatojejunostomy. However, preoperative knowledge of the D/P ratio could guide decision-making for primary pancreatectomy when pancreatic reconstruction is critical.

A faecal microbiota signature with high specificity for pancreatic cancer

BACKGROUND

Recent evidence suggests a role for the microbiome in pancreatic ductal adenocarcinoma (PDAC) aetiology and progression.

OBJECTIVE

To explore the faecal and salivary microbiota as potential diagnostic biomarkers.

METHODS

We applied shotgun metagenomic and 16S rRNA amplicon sequencing to samples from a Spanish case-control study (n=136), including 57 cases, 50 controls, and 29 patients with chronic pancreatitis in the discovery phase, and from a German case-control study (n=76), in the validation phase.

RESULTS

Faecal metagenomic classifiers performed much better than saliva-based classifiers and identified patients with PDAC with an accuracy of up to 0.84 area under the receiver operating characteristic curve (AUROC) based on a set of 27 microbial species, with consistent accuracy across early and late disease stages. Performance further improved to up to 0.94 AUROC when we combined our microbiome-based predictions with serum levels of carbohydrate antigen (CA) 19-9, the only current non-invasive, Food and Drug Administration approved, low specificity PDAC diagnostic biomarker. Furthermore, a microbiota-based classification model confined to PDAC-enriched species was highly disease-specific when validated against 25 publicly available metagenomic study populations for various health conditions (n=5792). Both microbiome-based models had a high prediction accuracy on a German validation population (n=76). Several faecal PDAC marker species were detectable in pancreatic tumour and non-tumour tissue using 16S rRNA sequencing and fluorescence in situ hybridisation.

CONCLUSION

Taken together, our results indicate that non-invasive, robust and specific faecal microbiota-based screening for the early detection of PDAC is feasible.

Metagenomic Identification of Microbial Signatures Predicting Pancreatic Cancer From a Multinational Study

BACKGROUND & AIMS

To identify gut and oral metagenomic signatures that accurately predict pancreatic ductal carcinoma (PDAC) and to validate these signatures in independent cohorts.

METHODS

We conducted a multinational study and performed shotgun metagenomic analysis of fecal and salivary samples collected from patients with treatment-naïve PDAC and non-PDAC controls in Japan, Spain, and Germany. Taxonomic and functional profiles of the microbiomes were characterized, and metagenomic classifiers to predict PDAC were constructed and validated in external datasets.

RESULTS

Comparative metagenomics revealed dysbiosis of both the gut and oral microbiomes and identified 30 gut and 18 oral species significantly associated with PDAC in the Japanese cohort. These microbial signatures achieved high area under the curve values of 0.78 to 0.82. The prediction model trained on the Japanese gut microbiome also had high predictive ability in Spanish and German cohorts, with respective area under the curve values of 0.74 and 0.83, validating its high confidence and versatility for PDAC prediction. Significant enrichments of Streptococcus and Veillonella spp and a depletion of Faecalibacterium prausnitzii were common gut signatures for PDAC in all the 3 cohorts. Prospective follow-up data revealed that patients with certain gut and oral microbial species were at higher risk of PDAC-related mortality. Finally, 58 bacteriophages that could infect microbial species consistently enriched in patients with PDAC across the 3 countries were identified.

CONCLUSIONS

Metagenomics targeting the gut and oral microbiomes can provide a powerful source of biomarkers for identifying individuals with PDAC and their prognoses. The identification of shared gut microbial signatures for PDAC in Asian and European cohorts indicates the presence of robust and global gut microbial biomarkers.

Orchestrating Treatment Modalities in Metastatic Pancreatic Neuroendocrine Tumors-Need for a Conductor

Simple Summary

Pancreatic neuroendocrine tumors (pNET) are a heterogeneous and challenging entity, and today’s guidelines offer a variety of treatment modalities, while surgery has a clear role for patients with resectable tumors and early stages, advanced, or metastatic pNET may benefit from treatments that were evaluated in randomized controlled studies during the last year. With this review, we aim to provide an updated view on treatment options for metastatic pNET.

Abstract

Pancreatic neuroendocrine tumors (pNETs) are a vast growing disease. Over 50% of these tumors are recognized at advanced stages with lymph node, liver, or distant metastasis. An ongoing controversy is the role of surgery in the metastatic setting as dedicated systemic treatments have emerged recently and shown benefits in randomized trials. Today, liver surgery is an option for advanced pNETs if the tumor has a favorable prognosis, reflected by a low to moderate proliferation index (G1 and G2). Surgery in this well-selected population may prolong progression-free and overall survival. Optimal selection of a treatment plan for an individual patient should be considered in a multidisciplinary tumor board. However, while current guidelines offer a variety of modalities, there is so far only a limited focus on the right timing. Available data is based on small case series or retrospective analyses. The focus of this review is to highlight the right time-point for surgery in the setting of the multimodal treatment of an advanced pancreatic neuroendocrine tumor.

The use of single-stapling techniques reduces anastomotic complications in minimal-invasive rectal surgery

BACKGROUND

Leakage of rectal anastomoses is one of the most important and feared complications in colorectal surgery. Apart from patient-specific risk factors, technical aspects may influence the occurrence of anastomotic complications. This study investigated whether using single-stapling techniques (SST) instead of the double-stapling technique (DST) for minimal-invasive rectal anastomosis is associated with a lower rate of anastomotic complications.

METHODS

A retrospective review of 272 patients who received a minimally invasive stapled rectal anastomosis (3-16 cm from the anal verge) at our institution from 2015 to 2020 was performed. In 131 patients, rectal anastomosis was created by SST (SST group), while 141 patients received a rectal anastomosis with crossing stapler lines (DST group). The impact of the anastomotic technique on patient outcomes was determined by uni- and multivariate analyses.

RESULTS

Overall anastomotic leakage rate was 6%. Patients with SST anastomoses had a lower leakage rate than patients with DST anastomoses (3% vs. 9% in the DST group, p = 0.045). The rate of anastomotic stenosis was lower in the SST group than in the DST group (1% vs. 6%, p = 0.037). Overall morbidity and mortality did not differ between the two groups. Multivariate analysis showed that single-stapling techniques significantly reduce the risk of anastomotic leakage (OR 3.5 [1.0-11.5], p = 0.043).

CONCLUSION

The use of SST for rectal anastomosis may help to reduce anastomotic complications. This finding should be confirmed by a randomized controlled trial.

Proposal of a Standardized Questionnaire to Structure Clinical Peer Reviews of Mortality and Failure of Rescue in Pancreatic Surgery

Background: Quality management tools such as clinical peer reviews facilitate root cause analysis and may, ultimately, help to reduce surgery-related morbidity and mortality. This study aimed to evaluate the reliability of a standardized questionnaire for clinical peer reviews in pancreatic surgery. Methods: All cases of in-hospital-mortality following pancreatic surgery at two high-volume centers (n = 86) were reviewed by two pancreatic surgeons. A standardized mortality review questionnaire was developed and applied to all cases. In a second step, 20 cases were randomly assigned to an online re-review that was completed by seven pancreatic surgeons. The overall consistency of the results between the peer review and online re-review was determined by Cohen’s kappa (κ). The inter-rater reliability of the online re-review was assessed by Fleiss’ kappa (κ). Results: The clinical peer review showed that 80% of the patient mortality was related to surgery. Post-operative pancreatic fistula (POPF) (36%) followed by post-pancreatectomy hemorrhage (PPH) (22%) were the most common surgical underlying (index) complications leading to in-hospital mortality. Most of the index complications yielded in abdominal sepsis (62%); 60% of the cases exhibited potential of improvement, especially through timely diagnosis and therapy (42%). There was a moderate to substantial strength of agreement between the peer review and the online re-review in regard to the category of death (surgical vs. non-surgical; κ = 0.886), type of surgical index complication (κ = 0.714) as well as surgical and non-surgical index complications (κ = 0.492 and κ = 0.793). Fleiss’ kappa showed a moderate to substantial inter-rater agreement of the online re-review in terms of category of death (κ = 0.724), category of common surgical index complications (κ = 0.455) and surgical index complication (κ = 0.424). Conclusion: The proposed questionnaire to structure clinical peer reviews is a reliable tool for root cause analyses of in-hospital mortality and may help to identify specific options to improve outcomes in pancreatic surgery. However, the reliability of the peer feedback decreases with an increasing specificity of the review questions.

Defining early recurrence in patients with resected primary colorectal carcinoma and its respective risk factors

PURPOSE

There is no evidence-based definition of early recurrence following resection of colorectal cancer. The purpose of this study is to define a point that discriminates between early and late recurrence in patients who have undergone colorectal cancer resection with curative intent and to analyze associated risk factors.

METHODS

A retrospective single-center cohort study was performed at a university hospital recognized as a comprehensive cancer center, specializing in colorectal cancer surgery. Patient data were retrieved from a prospectively maintained institutional database. Included patients underwent resection for primary, non-metastatic colorectal carcinomas with curative intent between 1995 and 2010. Aims of the study were (1) to define the optimal cut-off point of recurrence-free survival based on overall survival using a minimum p value approach and (2) to identify patterns of initial recurrence and putative risk factors for early recurrence using regression models.

RESULTS

Recurrence was diagnosed in 412 of 1893 patients. Statistical analysis suggested that a recurrence-free survival of 16 months could be used to distinguish between early and late recurrence based on overall survival (p < 0.001). Independent risk factors for early recurrence included advanced pT categories (pT3,4/ypT3,4) and positive lymph node status (pN+/ypN+). Early recurrence was independent of site of recurrence and was associated with worse prognosis.

CONCLUSIONS

Recurrence of colorectal carcinoma within 16 months after primary treatment should be labeled as "early." Tumor categories pT3,4/ypT3,4 and positive lymph node status pN+/ypN+ are predictive of early recurrence.

Microbiome Patterns in Matched Bile, Duodenal, Pancreatic Tumor Tissue, Drainage, and Stool Samples: Association with Preoperative Stenting and Postoperative Pancreatic Fistula Development

Postoperative complications after pancreatic surgery are still a significant problem in clinical practice. The aim of this study was to characterize and compare the microbiomes of different body compartments (bile duct, duodenal mucosa, pancreatic tumor lesion, postoperative drainage fluid, and stool samples; preoperative and postoperative) in patients undergoing pancreatic surgery for suspected pancreatic cancer, and their association with relevant clinical factors (stent placement, pancreatic fistula, and gland texture). For this, solid (duodenal mucosa, pancreatic tumor tissue, stool) and liquid (bile, drainage fluid) biopsy samples of 10 patients were analyzed using 16s rRNA gene next-generation sequencing. Our analysis revealed: (i) a distinct microbiome in the different compartments, (ii) markedly higher abundance of Enterococcus in patients undergoing preoperative stent placement in the common bile duct, (iii) significant differences in the beta diversity between patients who developed a postoperative pancreatic fistula (POPF B/C), (iv) patients with POPF B/C were more likely to have bacteria belonging to the genus Enterococcus, and (v) differences in microbiome composition with regard to the pancreatic gland texture. The structure of the microbiome is distinctive in different compartments, and can be associated with the development of a postoperative pancreatic fistula.

The TLR9 Agonist Cobitolimod Induces IL10-Producing Wound Healing Macrophages and Regulatory T Cells in Ulcerative Colitis

BACKGROUND AND AIMS

The topically applied Toll-like receptor 9 [TLR9] agonist cobitolimod is a first-in-class DNA-based oligonucleotide with demonstrated therapeutic efficacy in clinical trials with ulcerative colitis [UC] patients. We here characterized its anti-inflammatory mechanism in UC.

METHODS

Luminal cobitolimod administration was evaluated in an experimental dextran sodium sulfate [DSS]-induced colitis model. Cultured blood and mucosal cells from UC patients were treated with cobitolimod and analysed via microarray, quantitative real-time PCR, ELISA and flow cytometry. Intestinal slides of cobitolimod-treated UC patients were analysed by immunohistochemistry.

RESULTS

Cobitolimod administration markedly suppressed experimental colitis activity, and microarray analyses demonstrated mucosal IL10 upregulation and suppression of IL17 signalling pathways. Cobitolimod treatment was associated with significant induction of mucosal IL10+Tr1 and Treg cells and suppression of Th17 cells. TLR9 knockout mice indicated that cobitolimod requires TLR9 signalling for IL10 induction. In UC patients, mucosal TLR9 levels correlated with severity of inflammation. Cobitolimod inhibited IL17A and IL17F, but increased IL10 and FoxP3 expression in cultured intestinal UC T cells. Cobitolimod-mediated suppression of intestinal IL17+T cells was abrogated by IL10 blockade. Furthermore, cobitolimod led to heightened IL10 production by wound healing macrophages. Immunohistochemistry in intestinal biopsies of cobitolimod-treated UC patients indicated increased presence of IL10+mononuclear and regulatory T cells, as well as reduction of IL17+cells.

CONCLUSION

Activation of TLR9 via cobitolimod might represent a novel therapeutic approach in UC, as it suppresses Th17 cells and induces anti-inflammatory IL10+macrophages and regulatory T cells, thereby modifying the dysregulated intestinal cytokine balance.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

Risk factors for appendiceal neoplasm and malignancy among patients with acute appendicitis

PURPOSE

Non-operative management of acute uncomplicated appendicitis has shown promising results but might carry the risk of delayed diagnosis of premalignant or malignant appendiceal tumors found by chance in 0.7-2.5% of appendiceal specimen after appendectomy. Purpose of this study was to analyze whether appendiceal tumors are associated with a complicated appendicitis and to determine risk factors for appendiceal neoplasm and malignancy in patients with acute appendicitis.

METHODS

We performed a retrospective analysis of 1033 adult patients, who underwent appendectomy for acute appendicitis from 2010 to 2016 at the University hospital Erlangen. Data included patients' demographics; comorbidities; pre-, intra- and postoperative findings; and histopathological results. Complicated appendicitis was defined in the presence of perforation or abscess.

RESULTS

Appendiceal neoplasm respectively malignancy rate was 2.8% respectively 1.5%. Using univariate analysis, we identified seven risk factors at least for appendiceal neoplasm or malignancy: age, ASA, C-reactive protein, appendiceal diameter, perforation, intraoperative perithyphilitic abscess, and complicated appendicitis. Risk for appendiceal neoplasm or malignancy was 4.4% respectively 2.7% in complicated acute appendicitis compared to 2.0% respectively 1.0% in uncomplicated appendicitis (p = 0.043 respectively p = 0.060). In multivariate analysis, age ≥ 50 years and a diameter of the appendix in the sonography ≥ 13 mm were independent risk factors predicting the presence of appendiceal neoplasm and malignancy.

CONCLUSION

Among patients with appendicitis, there are relevant risk factors predicting appendiceal tumors, especially age and appendiceal diameter in sonography. But the identified risk factors have a low sensitivity and specificity, so obtaining a confident preoperative diagnosis is challenging.

Genome-wide association analysis of diverticular disease points towards neuromuscular, connective tissue and epithelial pathomechanisms

OBJECTIVE

Diverticular disease is a common complex disorder characterised by mucosal outpouchings of the colonic wall that manifests through complications such as diverticulitis, perforation and bleeding. We report the to date largest genome-wide association study (GWAS) to identify genetic risk factors for diverticular disease.

DESIGN

Discovery GWAS analysis was performed on UK Biobank imputed genotypes using 31 964 cases and 419 135 controls of European descent. Associations were replicated in a European sample of 3893 cases and 2829 diverticula-free controls and evaluated for risk contribution to diverticulitis and uncomplicated diverticulosis. Transcripts at top 20 replicating loci were analysed by real-time quatitative PCR in preparations of the mucosal, submucosal and muscular layer of colon. The localisation of expressed protein at selected loci was investigated by immunohistochemistry.

RESULTS

We discovered 48 risk loci, of which 12 are novel, with genome-wide significance and consistent OR in the replication sample. Nominal replication (p<0.05) was observed for 27 loci, and additional 8 in meta-analysis with a population-based cohort. The most significant novel risk variant rs9960286 is located near CTAGE1 with a p value of 2.3×10^-10 and 0.002 (OR_allelic=1.14 (95% CI 1.05 to 1.24)) in the replication analysis. Four loci showed stronger effects for diverticulitis, PHGR1 (OR 1.32, 95% CI 1.12 to 1.56), FAM155A-2 (OR 1.21, 95% CI 1.04 to 1.42), CALCB (OR 1.17, 95% CI 1.03 to 1.33) and S100A10 (OR 1.17, 95% CI 1.03 to 1.33).

CONCLUSION

In silico analyses point to diverticulosis primarily as a disorder of intestinal neuromuscular function and of impaired connective fibre support, while an additional diverticulitis risk might be conferred by epithelial dysfunction.

[Treatment and Prognosis of the Oldest Old with Colorectal Cancer]

INTRODUCTION

The demographic trend will lead to an increase of elderly persons in Germany in the future. The population is becoming smaller and older because of the deficiency in childbirths. This results in demographic ageing of the population in Germany. Studies addressing patients ≥ 85 years, the oldest old, are becoming more and more important.

MATERIALS AND METHODS

The prospectively collected data of 141 patients ≥ 85 years with colorectal carcinoma treated between 1995 and 2014 were analysed retrospectively. Treatment, complications and prognosis were compared with a historical group of patients ≥ 85 years treated previously between 1978 and 1994 (n = 57) and with a less old group of patients 75 - 84 years old treated between 1995 and 2014 (n = 726).

RESULTS

The cohort consisted of 64 men and 77 women. 88 patients had colon carcinoma, 53 patients rectal carcinoma. 127 patients were treated with tumour resection; 112 were classified as R0. Compared with the historical cohort (1978 - 1994), the number of patients increased, and more patients were given tumour resection (74 vs. 90%, p = 0.003) and fewer patients had synchronous distant metastases (28 vs. 14%, p = 0.015). The 5-year locoregional recurrence rate after curative resection decreased from 11.5 to 1.4% (p = 0.027). Comparison with the younger age group (75 - 84 years) revealed more women (55 vs. 42.3%, p = 0.007), more emergencies (22 vs. 9.8%, p < 0.001) and less frequent neoadjuvant treatment (11 vs. 3%, p = 0.003). Morbidity (41 vs. 31.2%, p = 0.032) and mortality (16 vs. 5%, p < 0.001) were higher in the oldest old. After curative resection and exclusion of postoperative deaths, overall survival (2-year rate 66.4%, 5-year rate 32.9%) was found to be worse than for the less old group, whereas cancer-related survival (2-year rate 93.1%, 5-year rate 86.7%) was similar.

CONCLUSION

The number of oldest old patients ≥ 85 years with colorectal carcinoma will further increase. These patients have a higher risk of postoperative complications. After recovering from the surgery cancer-related survival is not worse than for less old patients.

Isolation of Human Endothelial Cells from Normal Colon and Colorectal Carcinoma - An Improved Protocol

Primary cells isolated from human carcinomas are valuable tools to identify pathogenic mechanisms contributing to disease development and progression. In particular, endothelial cells (EC) constituting the inner surface of vessels, directly participate in oxygen delivery, nutrient supply, and removal of waste products to and from tumors, and are thereby prominently involved in the constitution of the tumor microenvironment (TME). Tumor endothelial cells (TECs) can be used as cellular biosensors of the intratumoral microenvironment established by communication between tumor and stromal cells. TECs also serve as targets of therapy. Accordingly, in culture these cells allow studies on mechanisms of response or resistance to anti-angiogenic treatment. Recently, it was found that TECs isolated from human colorectal carcinoma (CRC) exhibit memory-like effects based on the specific TME they were derived from. Moreover, these TECs actively contribute to the establishment of a specific TME by the secretion of different factors. For example, TECs in a prognostically favorable Th1-TME secrete the anti-angiogenic tumor-suppressive factor secreted protein, acidic and rich in cysteine-like 1 (SPARCL1). SPARCL1 regulates vessel homeostasis and inhibits tumor cell proliferation and migration. Hence, cultures of pure, viable TECs isolated from human solid tumors are a valuable tool for functional studies on the role of the vascular system in tumorigenesis. Here, a new up-to-date protocol for the isolation of primary EC from the normal colon as well as CRC is described. The technique is based on mechanical and enzymatic tissue digestion, immunolabeling, and fluorescence activated cell sorting (FACS)-sorting of triple-positive cells (CD31, VE-cadherin, CD105). With this protocol, viable TEC or normal endothelial cell (NEC) cultures could be isolated from colon tissues with a success rate of 62.12% when subjected to FACS-sorting (41 pure EC cultures from 66 tissue samples). Accordingly, this protocol provides a robust approach to isolate human EC cultures from normal colon and CRC.

Reduced circulating B cells and plasma IgM levels are associated with decreased survival in sepsis - A meta-analysis

BACKGROUND

B cell function and antibody production are crucial factors in host protection during inflammation. We aimed to synthesize the available evidence on the association between the reduction of circulating B cells and plasma immunoglobulin (IgM) levels and decreased survival during sepsis.

METHODS

We performed a systematic search in PubMed, Embase, ISI Web of Knowledge, Cochrane Central Register of Controlled Trials, BioMed Central, and Science Direct. We selected studies with data on circulating B cells and plasma IgM levels within the initial 24 h after sepsis onset.

RESULTS

In total nine studies (n = 992 patients) were identified. Circulating B cells were reduced in septic patients as compared to non-septic patients (mean difference [MD] -88.2 cells/μl; 95% confidence interval [CI] -148.6--27.9). Sepsis non-survivors showed a significant reduction of circulating B cells and IgM levels compared to sepsis survivors (MD -77.1 cells/μl; 95% CI -111.4--42.7 and MD -20.9 mg/dl; 95% CI -33.8--8.0, respectively).

CONCLUSIONS

Our results suggest that a reduction of circulating B cells and IgM levels at sepsis onset are associated with decreased sepsis survival. However, due to methodological limitations and the risk of bias, we need further prospective studies to confirm this association.

REGISTRATION

The protocol was registered (PROSPERO 2016:CRD42016053184).

Metastatic adenocarcinomas of the stomach or esophagogastric junction (UICC stage IV) are not always a palliative situation: a retrospective analysis

BACKGROUND

Gastric cancer is one of the most common cancers. Unfortunately, it is often diagnosed at the advanced stage International Union Against Cancer stage IV. This induced us to carry out an interdisciplinary analysis of this patient group with the Department of Internal Medicine 1. Our aim was to discuss cancers classified initially as unresectable in a meeting of the interdisciplinary tumor board after palliative chemotherapy, and to refer selected patients for surgery after establishing resectability. The outcome of the chemotherapy, operation method, complication rate, and long-term survival were analyzed.

METHODS

From 1999 to 2008, 76 patients with metastatic gastric cancer or carcinoma of the esophagogastric junction were discussed by the interdisciplinary tumor board of the University of Erlangen and classified initially as unresectable. The patients then received palliative chemotherapy according to the AIO regimen (weekly high-dose 5-fluorouracil/folinic acid [FU/FA] in a 24 h infusion), plus irinotecan. If the tumor was subsequently classified as resectable, the patient underwent either gastric resection or gastrectomy with DII-III dissection. Metastases were resected depending on their location (liver). Peritoneal carcinomatosis was treated additionally by HIPEC. Statistical analysis was with SPSSS version 20.

RESULTS

Surgical and general complications and hospital mortality were acceptable. There were no cases of anastomotic leak, but one patient died of fulminant pneumonia. The R0 resection rate was 69 %, and four patients had long-term survival of more than 60 months. There were significant survival advantages.

CONCLUSIONS

Metastatic gastric cancer or carcinoma of the esophagogastric junction can become resectable after downsizing the tumor with palliative chemotherapy. Long-term survival is achieved in some cases. Therefore, every patient with this type of cancer should be discussed by the interdisciplinary tumour board after palliative chemotherapy to provide him with a chance of cure after re-evaluation.

Long-term outcome of liver transplantation as treatment modality in patients with hepatocellular carcinoma in cirrhosis: a single-center experience

BACKGROUND

Hepatocellular carcinoma (HCC) is among the most frequent malignant diseases worldwide. In the vast majority of cases, it is associated with liver cirrhosis. Liver transplantation (OLT) is potentially the gold standard treatment for patients suffering HCC in cirrhosis, because of synchronous eradication of HCC and of the underlying hepatic disease. The aim of this study was to evaluate long-term outcomes of OLT in HCC patients.

MATERIAL AND METHODS

Between January 2000 and December 2011, 43 patients who were diagnosed with HCC in liver cirrhosis and underwent OLT in our department, were identified from a prospective database. All patients received their grafts from deceased donors. We analyzed demographic data, laboratory values, number and size of lesions, primary liver disease, diagnostic methods, bridging therapy modalities, and postoperative outcomes, including complications, recurrences, and their treatment.

RESULTS

Patient follow-up as of January 2012 or to death ranged from 0 to 138 months (median, 59; mean, 63). None of the patients were lost to follow-up. The gender bias was 85%:15% (male:female) and the median age, 57.8 years (range, 44-69). The most common underlying diseases for cirrhosis and HCC were alcoholic (n = 12) and hepatitis C (n = 16). Thirty-one subjects underwent bridging therapy through transarterial chemoembolization (TACE), and/or radiofrequency ablation. All patients underwent OLT within the Milan criteria according to the preoperative evaluation and histopathologic examination of the explanted liver. Twenty-one of them suffered postoperative complications (48.8%). HCC recurrence, which occurred in 5 (10.4%), was treated by surgery (n = 3), systemic chemotherapy with sorafenib (n = 1), or TACE (n = 1).

CONCLUSIONS

OLT for HCC in cirrhosis, displays a relatively high complication rate. It shows good survivals with and low recurrence.

Management of hemangioma of the liver: surgical therapy or observation?

BACKGROUND

Elective surgery for liver hemangioma is controversial. We reviewed long-term outcomes following elective hepatectomy or observation only for symptomatic and asymptomatic liver hemangioma.

METHODS

All patients (n = 307) with liver hemangioma referred to our hospital for surgical evaluation from January 1988 to December 2009 were identified, and imaging results, tumor characteristics, surgical indication, surgical mode, outcome of observation, clinical and/or postoperative outcome, and adverse events were retrospectively evaluated.

RESULTS

Complete median follow-up for 246 patients was 124 months. Elective surgery was performed in 103 patients (symptomatic [n = 62] and asymptomatic [n = 41]). Postoperative morbidity occurred in 17 % of the patients and was significantly lower in asymptomatic patients (p = 0.002). No perioperative mortality was registered. Surgery relieved complaints in most (88 %) patients. In the observation group (n = 143), 56 % of patients had persistent or new onset of hemangioma-associated symptoms. Major hemangioma-related complications occurred in 12 patients (9 %) during the follow-up period, and 2 patients died after traumatic hemangioma rupture. Overall the rate of adverse events was by trend lower in the surgical group than in the observation group (35 versus 57 %; p = 0.08).

CONCLUSIONS

The majority of patients with liver hemangioma can be safely managed by clinical observation. In a subset of patients, especially those with giant hemangioma and/or occurrence of symptoms, surgical treatment could be considered and is justified in high-volume centers.

Tumor-associated fibroblasts isolated from colorectal cancer tissues exhibit increased ICAM-1 expression and affinity for monocytes

Progression of colorectal cancer (CRC) is strongly associated with inflammation and other desmoplastic reactions in the tumor cell-surrounding tissue. We successfully isolated fibroblasts from the desmoplastic stroma of human CRC specimens and uninvolved colon tissue of patients treated surgically for CRC and investigated potential functional capacities. All of the isolated fibroblasts were vimentin-positive and CK-20/CD45-negative confirming the fibroblast phenotype. Differential expression patterns were detected between tumor-associated fibroblasts (TAFs) and normal tissue-associated fibroblasts (NAFs) regarding intercellular adhesion molecule-1 (ICAM-1) expression. In 11 of 12 TAF cultures, basal ICAM-1 expression was increased as compared to corresponding NAF cultures (p=0.001). After stimulation of the cultures with interleukin-1β, 8 of the 12 TAF cultures presented higher ICAM-1 levels when compared with the level in the corresponding NAF cultures (p=0.001). Moreover, the adhesive capacity of these cultures for U937 was increased in 8 out of 10 unstimulated and in 10 out of 10 stimulated cultures when TAFs and NAFs were compared. In corresponding tumor tissue sections from the same patients, the amount of ICAM-1-positive fibroblasts was significantly higher than that in the corresponding normal colon mucosa, indicating a tumor-specific effect that was maintained in the isolated cultures. These results indicate that fibroblasts from CRC tissue exhibit an increased affinity for monocytic cells. This increased intercellular interaction may contribute to elongated residence times of monocytes in CRC tissue. Therefore, these isolated fibroblasts are a useful tool for further functional investigation of desmoplastic tissue reactions in CRC.

[Colorectal Carcinoma in Young Patients - Is Age a Prognostic Factor?]

INTRODUCTION

Concerning younger patients with colorectal carcinoma (CRC) controversies still exist regarding outcome. The aim of this study was to evaluate possible differences between patients suffering from CRC at a younger age (< 40 years) and at an age over 40 years.

PATIENTS AND METHODS

Data of 51 younger patients (< 40 years) and 2122 older patients (≥ 40 years) were prospectively collected and retrospectively evaluated according to clinical parameters, treatment and prognosis. Patients with a CRC arising from familial adenomatous polyposis, ulcerative colitis or Crohn's disease have been excluded.

RESULTS

The younger patients presented significantly more often with mucinous adenocarcinomas (p = 0.033). There were no differences between the groups concerning gender, localisation, elective and emergency surgery, UICC (Union internationale contre le cancer) stages and residual tumour classification. Postoperative therapy - in adjuvant, therapeutic or palliative intent - was applied significantly more often in younger patients, especially in those with colon carcinoma (p = 0.001). After curative resection of colon carcinoma a significantly better observed (5 year rate 94 vs. 76 %; p = 0.024) and disease-free (88 vs. 69 %; p = 0.013) survival were found. This trend was similar in patients with rectal carcinoma (84 vs. 75 % and 72 vs. 65 %) without reaching the level of significance (p = 0.155 and 0.269). Taking into account differences in life expectancy, just minor differences were detected in relative survival (colon carcinoma, 5 year rate 94 vs. 89 %; rectal carcinoma, 84 % both).

CONCLUSIONS

The general assumption of a poorer prognosis in younger patients with CRC could not be confirmed. Younger patients have a poorer histological subtype of carcinoma. But this is compensated by the better overall condition, less comorbidities, faster postoperative recovery and an optimally organised post-operative (adjuvant, therapeutic or palliative) therapy. In summary, younger patients have a better observed survival but - considering differences in life expectancy - a similar relative survival.

Expression of annexin AI in conventional renal cell carcinoma (CRCC) correlates with tumour stage, Fuhrman grade, amount of eosinophilic cells and clinical outcome

There is increasing evidence that Annexin AI (ANX AI) expression is dysregulated in several carcinomas and tumour cell lines. In order to gain insight into the putative role of ANX AI in tumorigenesis, clinical outcome and metastatic potential of conventional renal cell carcinomas (CRCCs) we investigated the expression of ANX AI in CRCCs and metastases. Furthermore, it was elucidated whether ANX AI overexpression affects migratory potential in Caki-1 cells. ANX AI immunohistochemistry was performed on 33 samples of CRCCs and 10 metastases. ANX AI expression was assessed in 12 samples by 2-dimensional gelelectrophoresis (2-DE), subsequent mass spectrometry and RT-PCR. Immunohistochemical data were statistically correlated with pathological parameters, amount of eosinophilic cells and clinical outcome. Furthermore, a haptotactic migration assay was done on Caki-1 cells transfected with ANX AI. Immunostaining for ANX AI was found in 18 tumours and all metastases investigated. Intensity of immunohistochemical staining correlated to Fuhrman grade, amount of eosinophilic cells and clinical outcome. 2-DE and RT-PCR confirmed the presence of ANX AI in neoplastic tissue. Overexpression of ANX AI did not significantly influence cell migration. From these findings ANX AI expression seems to be related to Fuhrman grade, clinical outcome and metastatic potential of CRCCs. Thus ANX AI could serve as a prognostic marker for tumour progression.

Pharmacokinetic interaction of digoxin with an herbal extract from St John's wort (Hypericum perforatum)

OBJECTIVE

Extracts of St John's wort (Hypericum perforatum) are widely used in the treatment of depression, often as an over-the-counter drug. In contrast to its frequent use, knowledge about the pharmacokinetics of ingredients and drug interactions of St John's wort is poor. We studied the interaction between hypericum extract LI160 and digoxin.

METHODS

The pharmacokinetics of digoxin were investigated in a single-blind, placebo-controlled parallel study. After the achievement of steady state for digoxin on day 5, healthy volunteers received digoxin (0.25 mg/d) either with placebo (n = 12) or with 900 mg/d LI160 (n = 13) for another 10 days. Digoxin concentration profiles on day 5 were compared with day 6 (single-dose interaction) and day 15 (tenth day of co-medication).

RESULTS

There was a highly significant combined-day-and-group effect for digoxin area under the plasma concentration-time curve [AUC(0-24); P = .0001], peak concentration in plasma (Cmax; P = .0001), and plasma drug concentration at the end of a dosing interval (P = .0003) by two-way ANOVA. No statistically significant change was observed after the first dose of hypericum extract [AUC(0-24) at day 6 of 18.1+/-2.9 microg x h/L and 17.7+/-3.0 microg x h/L, mean +/- SD for placebo and hypericum group, respectively]. However, 10 days of treatment with hypericum extract resulted in a decrease of digoxin AUC(0-24) by 25% (day 15, 17.2+/-4.0 microg x h/L and 12.9+/-2.3 microg x h/L; P = .0035). Furthermore, comparison with the parallel placebo group after multiple dosing showed a reduction in trough concentrations and Cmax of 33% (P = .0023) and 26% (P = .0095), respectively. The effect became increasingly pronounced until the tenth day of co-medication.

CONCLUSION

As with grapefruit juice, a food product, physicians should also be aware of potential drug-herb interactions. The interaction of St John's wort extract with digoxin kinetics was time dependent. The mechanism involved may be induction of the P-glycoprotein drug transporter.

Hypericin levels in human serum and interstitial skin blister fluid after oral single-dose and steady-state administration of Hypericum perforatum extract (St. John's wort)

The photodynamically active plant pigment hypericin, a characteristic metabolite of Hypericum perforatum (St. John's wort), is widely used as an antidepressant. When administered orally, phototoxic symptoms may limit the therapeutic use of hypericin-containing drugs. Here we describe the high-performance liquid chromatographic (HPLC) detection of hypericin and semiquantitative detection of pseudohypericin in human serum and skin blister fluid after oral single-dose (1 x 6 tablets) or steady-state (3 x 1 tablet/day, for 7 days) administration of the Hypericum extract LI 160 in healthy volunteers (n = 12). Serum levels of hypericin and pseudohypericin were always significantly higher than skin levels (p </= 0.01). After oral single-dose administration of Hypericum extract the mean serum level of total hypericin (hypericin + pseudohypericin) was 43 ng/ml and the mean skin blister fluid level was 5.3 ng/ml. After steady-state administration the mean serum level of total hypericin was 12.5 ng/ml and the mean skin blister fluid level was 2.8 ng/ml. These skin levels are far below hypericin skin levels that are estimated to be phototoxic (>100 ng/ml).

The hypertensive Ren-2 transgenic rat TGR (mREN2)27 in hypertension research. Characteristics and functional aspects

Primary human hypertension is a polygenic disorder. It is the prevalent cause of cardiovascular disease leading to cardiac failure, stroke, chronic renal failure and, ultimately to death. Several genes are involved in cardiovascular control mechanisms and their genetics are complex. Experimental models which are well defined are needed to clarify the role of individual genes. The generation of the hypertensive transgenic rat line TGR (mREN2)27 bearing the murine Ren-2 gene cloned from the DBA/2J mouse strain provides a monogenic model of hypertension in which the genetic basis (the additional renin gene) is known. These rats develop severe hypertension, which reaches 200 mm Hg and higher at 8 weeks of age in the heterozygous animal. Homozygous rats develop even higher blood pressures than heterozygous animals, which is paralleled by a higher mortality rate in homozygous rats. Animals develop pathomorphologic alterations which are characteristic for systemic hypertension. The transgenic rats are characterized by unchanged or even suppressed concentrations of active renin, angiotensin I (ANG I), ANG II, and angiotensinogen compared to transgene-negative littermates. In contrast, plasma levels of inactive renin (prorenin) are much higher in TGR (mREN)27 rats than in control animals. In the kidneys, renin is suppressed, probably mediated through negative feedback inhibition, in other tissues, especially in the adrenal gland, murine Ren-2 mRNA is expressed at very high levels. The cascade of pathophysiologic events which finally lead to hypertension is not fully understood in this rat model. Treatment with ACE inhibitors or angiotensin II receptor antagonists such as losartan is extremely efficient, which could mean that hypertension in this model is mediated through ANG II. Since the the renin-angiotensin system (RAS) in the kidneys is suppressed, other ANG II generating sites must be considered. This favors the concept of extrarenal RASs in this model.

Role of the cardiac renin-angiotensin system in human heart failure

The local effects of angiotensin II (ANG II) on the heart may play an important role for the pathophysiology of cardiovascular disease. Numerous in vitro studies have demonstrated that angiotensin II has distinctive cellular effects in the cardiovascular system which are independent from its effects on blood pressure. These have led to the hypothesis that activation of the angiotensin system in the heart could be of functional relevance for the adaptive processes in several cardiovascular disorders such as cardiac hypertrophy heart failure. This concept has been further supported by clinical studies showing the beneficial effects of angiotensin-converting enzyme inhibitors in these circumstances. In order to study the gene regulation of renin-angiotensin system components in cardiac disorders we investigated the gene expression of angiotensin converting enzyme in human heart failure. Results showed that the enzyme is activated locally in this condition, supporting previous studies in animals. Taken together with recent evidence from genetic studies linking the enzyme to myocardial infarction and cardiac hypertrophy, our findings are in support of the notion that angiotensin converting enzyme plays a central role in cardiovascular physiology and pathophysiology.

PCR analysis of human renal biopsies--renin gene regulation in glomerulonephritis

Animal studies show that the renin-angiotensin system contributes to hypertension, glomerulosclerosis and progressive chronic renal failure in renal disease. Direct data on the activity of the renal renin-angiotensin system (RAS) in human renal disease are scarce, however. The small amount of tissue in renal biopsies and insufficient sensitivity of analytical methods have precluded reliable measurements of the tissue components of the RAS in the past. Due to its highly sensitivity the quantitative polymerase chain reaction (QPCR) assay today allows the quantitation of gene transcription products in small tissue samples, for example, renal biopsies. The clinical applicability of the PCR has raised the interest in this methodology. We adopted quantitative PCR to study expression and regulation of the renin gene in patients with different forms of glomerulonephritis. For PCR a deletion mutant of the renin gene was used as an internal standard exhibiting the same primer binding sites as the human gene. The number of glomeruli per biopsy sample was counted by microscopic transillumination immediately after biopsy and was used as a reference base. Renin mRNA was expressed as fg per glomerulus. Compared to nonaffected tissue of tumor nephrectomy samples, renin gene expression was significantly lower in glomerulonephritic patients without converting enzyme inhibitor (CEI) treatment, that is, 63 +/- 20 (6) versus 250 +/- 50 (7) (P < 0.02), although plasma renin concentration was in the normal range. Significantly higher renin mRNA expression was found in patients with glomerulonephritis treated with CEI, that is, 210 +/- 50 (8) versus 63 +/- 20 (6) in patients not treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucose content and efficiency of glycolysis in protected ischemic kidneys of different species

In ischemic canine kidneys protected by Bretschneider's HTK solution the glycolytic lactate production is limited by a low renal substrate content. However, for anaerobic energy supply ischemic organs depend on glycolysis. To evaluate the role of glycolysis in renal protection, the relationship between lactate production and anaerobic energy supply was examined in protected kidneys of dogs, sheep, and swine. Additionally, in canine kidneys an attempt was made to improve anaerobic energy provision by adding glucose to the protective solution. The results were as follows: (1) According to increasing lactate production from swine to dog to sheep, intraischemic ATP decay was delayed least in swine and most in sheep. (2) Glucose addition (10 mM) to the HTK solution roughly doubled the time for ATP to fall to 1 mumol/g dry wt (tATP) in dogs. (3) The greater the lactate production in all three species, the lower the decrease in SAN (ATP + ADP + AMP) from 5 to 120 min of ischemia. (4) A glucose additive in the protective solution led to a significant (p less than .005) increase of SAN in dogs at 120 min of ischemia. A sufficient substrate supply seems to be an essential component of a reliable renal protection.

Contribution of amino acids in protective solutions to postischemic functional recovery of canine kidneys

Amino acids are known to increase glomerular filtration rate (GFR). There is also an early resumption of filtration following 2-h renal ischemic stress under protection by histidine-buffered histidine-tryptophan-ketoglutarate solution (HTK), possibly due in part to an amino acid effect. Hence, we have examined the possibility of further enhancing the postischemic GFR by adding 32 (ASP I; 4 mM Mg2+) or 36 (ASP II; 6 mM Mg2+) mM L-aspartate (asp) or 32 mM DL-aspartate (ASP III) to the HTK solution in place of chloride. After infusion of 500 ml 5% glucose, canine kidneys were protected by an 8-min perfusion with HTK (n = 5), ASP I (n = 4), ASP II (n = 5) or ASP III-solution (n = 3). The subsequent ischemia lasted for 2 h at 27-31 degrees C. During reperfusion, both GFR and filtration fraction (FF) were higher in kidneys protected by L-aspartate-containing solutions. ASP III showed no improvement against HTK. An additional preischemic intra-aortal application of HTK or ASP I solution just above the exit of the renal arteries prior to the intrinsic protective perfusion further raised the postischemic GFR. The present results suggest that L-aspartate but also histidine may have favorable amino acid effects in renal protective solutions in addition to known positive effects of histidine.

Postischaemic interrelations between energy metabolism and functional recovery of protected canine kidneys

Following renal ischaemia under effective protection glomerular filtration starts at a time when renal high-energy phosphates are resynthesized. The present investigation was carried out to examine the interdependence of the two processes. Therefore, canine kidneys were protected with sodium poor and nominally Ca2+ free buffered solutions. After different times of ischaemia and reperfusion the glomerular filtration rates (GFR) were determined and afterwards tissue specimens were excised for the determination of high-energy phosphates. Both the GFR and the renal energy content were higher with shorter ischaemia periods or longer reperfusion. As a rule there was a correlation between GFR and ATP, both probably mainly signifying the degree of preservation of proximal nephron sites, as the interrelation between the GFR and the renal SAN (ATP + ADP + AMP) content also signifies. However, with the addition of aspartate to the protective solution it could be demonstrated that the GFR also can rise without a concomitant increase of ATP. Under certain conditions an increase of GFR can even be associated with a lowering of the renal ATP content.

Metabolic, energetic and structural changes in protected and unprotected kidneys at temperatures of 1 degree C and 25 degrees C

In 110 canine kidneys, we examined the time course of energy rich phosphates, lactate, intrarenal ph and renal morphology with Euro-Collins- or with HTK-protection of Bretschneider and compared these findings with unprotected kidneys during complete ischemia at 1 degree C and at 25 degrees C. Both kidney protective solutions prolonged energy-rich phosphate-decline by a factor of 3-4 compared with that of unprotected kidneys. The lactate increase was greater in Euro-Collins-protected kidneys than in HTK-protected and in unprotected kidneys, leading to pH values of 6.5 in Euro-Collins and to 6.4 in unprotected kidneys after 24 hours, in contrast to a pH-value of 7.3 with HTK-protection. This may be the reason for structural deterioration seen in unprotected and in Euro-Collins-protected kidneys after 12, and 48 h of ischemia at 1 degree C, whereas in HTK-protected kidneys a sufficient preservation of structure can be seen. In one human kidney, protected with Euro-Collins-solution, we were able to show that at 1 degree C intrarenal pH and lactate accumulation is similar to the levels in canine kidneys. In Euro-Collins preserved kidneys lactate accumulation at 25 degrees C is even greater than at 1 degree C, leading to inhibition of energy metabolism and to structural deterioration, whereas HTK-solution, because of its high buffer concentration, is able to maintain ischemic metabolism leading to sufficient protection of intrarenal pH and of adenine nucleotides as well as structural protection at 1 degree C and at 25 degrees C.

Effects of glucose in protected ischemic kidneys

Energy reserves (TAN) and anaerobic substrates (glucose, glycogen) are lower in renal than in myocardial tissue. Euro-Collins-solution contains nearly 200 mmol/l glucose, while the HTK-solution of Bretschneider contains none. Therefore the influence of glucose on kidney lactate production, on energy reserves (TAN), intrarenal pH and on morphology during the protection of ischemic kidneys was analysed using either Euro-Collins-solution, or modified "Euro-Collins-solution", containing mannitol instead of glucose, or HTK-solution with and without the addition of 5, 10 and 20 mmol/l glucose. Glucose content changed during kidney perfusion with Euro-Collins-solution from about 60 to 800 mumol/gdw. While intrarenal pH decreased from 7.1 to 5.1 in Euro-Collins-kidneys during 420 min of ischemia at 25 degrees C, pH decreased to 6.7 with the modified, mannitol containing "Euro-Collins-solution". In HTK-protected kidneys intrarenal pH decreased with increasing glucose addition to the solution. Although Total Adenine Nucleotides are highest at the end of ischemia with Euro-Collins-solution, structural protection after the same ischemic stress was best in HTK-protected kidneys without glucose addition. We conclude that glucose stimulated lactate production, reduced interstitial pH in the kidney even in combination with a highly buffered solution and that it might cause greater membrane permeability leading to a structural deterioration. Mannitol seemed more appropriate than glucose in this respect, although other substances, which provide energy substrate and prevent structural damage, may exist.

[Kidney function parameters following ischemia stress using the Euro-Collins solution or the Bretschneider cardioplegic HTK solution]

Protection-methods, for an improvement of ischemic tolerance of the kidney, can be investigated by intraischemic analysis of metabolism and structure. A definite proof for the effectiveness of a protection method is only postischemic function in combination with postischemic structure-regeneration. For this reason postischemic function was chosen for examination of the protective ability of the Euro-Collins-solution and the HTK-solution during a two-hour reperfusion period. We perfused 57 dog kidneys either with the Euro-Collins- or with the HTK-solution prior to ischemia. Ischemia was 7, 60, 90 and 120 min after Euro-Collins-perfusion and 7, 120, 150 and 180 min after HTK-protection. The protected and ischemic kidneys were left in-situ; the mean ischemic temperature was therefore 20-25 degrees C for the shorter ischemic times and 30-34 degrees C for the longer ischemic times. We compared the protected and ischemic kidneys with 14 untreated kidneys (control). Postischemic renal blood flow (RBF) was measured by an electromagnetic flow probe; renal oxygen consumption (V02/min) was calculated by arterio-venous oxygen content difference and the renal blood flow. If urine could be collected, the glomerular filtration rate (GFR) was measured by an endogenous creatinine clearance. In Euro-Collins-protected kidneys after 60-120 min ischemia the RBF was after 15 min of reperfusion between 20 and 100 ml/min/100 g. After 30 min we got values of 100-200 ml/min/100 g. The V02/min, which was in the control kidneys between 5-6 ml/min/100 g, was about 2 ml/min/100 g.(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term perfusion and "equilibration" of canine kidneys with protective solutions

Kidneys were perfused either with Euro-Collins-solution or with HTK-solution of Bretschneider. The perfusion pressure as well as the perfusion flow were measured during a six-minute perfusion. The perfusion resistance was higher in Euro-Collins-kidneys than during HTK-perfusion. The venous outflow of the kidney as well as the ureteral outflow was measured during each minute of the perfusion and has analysed for osmolality, and for sodium and potassium concentrations. In Euro-Collins-kidneys a complete "equilibration" of the extracellular space was not achieved, while during HTK-perfusion concentrations in the venous as in the tubular outflow, similar to those in the HTK-solution itself, could be reached. At the end of the different perfusions, tissue was analysed for biochemical parameters such as ATP, ADP, AMP and lactate as well as for morphological features. Lactate had increased and ATP had decreased during perfusion with Euro-Collins-solution, while ATP had not changed and lactate had decreased during perfusion with HTK-solution. Normal glomerular, tubular and dilated vascular structures can be seen after HTK-perfusion, while a glomerular and vascular contraction takes place during Euro-Collins-perfusion.