Studies in rodents with the dipeptidyl peptidase-4 inhibitor vildagliptin to evaluate possible drug-induced pancreatic histological changes that are predictive of pancreatitis and cancer development in man

AIM

The present report summarizes rodent studies with vildagliptin, relevant to predicting pancreatitis or pancreatic cancer in man.

METHODS

As part of the regulatory development program for vildagliptin, a rodent toxicity program included two 104-week rodent (mouse and rat) carcinogenicity studies that were conducted according to guidelines assigned in Food and Drug Administration's Draft Guidance for Industry.

RESULTS

Vildagliptin exposure in animals was evaluated for its effects on endocrine and exocrine pancreas. Two-year carcinogenicity studies were conducted in rats at oral doses up to 900 mg/kg (approximately 200 times the human exposure at the maximum recommended dose) and in mice at oral doses up to 1000 mg/kg (up to 240 times the human exposure at the maximum recommended dose). The results from these studies show the expected preservation and growth of the endocrine β-cells with no significant findings in the exocrine acinar pancreas. There was no evidence of inflammatory infiltrates characteristic of pancreatitis, no palpable mass detection based on gross examination or any microscopic findings indicative of pancreatic islet cell (endocrine), acinar cell (exocrine) or ductal (exocrine) neoplasia in rat or mouse.

CONCLUSIONS

Evaluation of vildagliptin in 2-year preclinical carcinogenicity studies in both rats and mice indicates that while vildagliptin results in pharmacological benefits to the endocrine pancreas, this was not associated with any evidence of pancreatitis, pancreatic islet cell, acinar cell or ductal neoplasia. These data predict no increased risk of pancreatic cancer in man.

[Phytobezoar in the common hepatic duct - rare cause of obstructive jaundice following pancreatoduodenectomy: case report and review of the literature]

Obstruction of bile flow following pancreatoduodenectomy can be caused by stenosis of the hepaticojejunostomy created at the time of surgery, obstruction of the bile-draining jejunal loop, stones or, very rarely, ingested foreign bodies in the common hepatic duct. In analogy with endoscopic sphincterotomy or the once popular side-to-side-choledochduodenostomy, the creation of a hepaticojejunostomy eliminates the barrier of the sphincter Oddi, enabling intestinal content such as ingested foreign bodies or food fibers to migrate into the bile duct. We report on the case of a patient developing biliary tract obstruction due to fibrous material in the common hepatic duct 15 years after pancreatoduodenectomy. In addition, an overview of the literature on the rare phenomenon of foreign body-associated obstructive jaundice is given.

[Acute scrotum in childhood]

BACKGROUND

Due to the variety of differential diagnoses causing acute scrotum and their possible consequences, this finding is a challenge for diagnostic and therapeutic management in the daily clinical practice of paediatric medicine.

PATIENTS AND METHODS

Through a defined time period, all consecutive paediatric patients of a tertiary surgical centre aged up to 16 years who were diagnosed with and treated for primary acute scrotum were prospectively registered and retrospectively evaluated for patient, finding and treatment (intervention) associated specifics in this systematic unicentric observational study (design: case series) to reflect daily clinical practice.

RESULTS

A total of 141 cases with acute scrotum were enrolled in the study during the 10-year period from January 2000 to December 2009. Eight percent of cases (n = 11) showed bilateral findings. There were two age peaks: newborns and puberty. The most common diagnoses were epididymitis and orchitis (26 %), torsion of the testicular appendix (22 %) and testicular torsion (21 %). Trauma, hydrocele, inguinal hernia, idiopathic scrotal oedema and tumours were rather rare differential diagnoses as possible causes for an acute scrotum. The mean period of discomfort, complaints and symptoms up to presenting in the outpatient clinic was 24 hours. For sixty percent (n = 84, i.e., all patients treated conservatively and 43 % of the operated patients) an imaging study was obtained with ultrasound or Doppler ultrasonography, respectively. Two thirds of the patients underwent an operative exploration. The orchiectomy rate in testicular torsion amounted to 40 %. In one newborn, a bilateral orchiectomy was necessary. In patients with unilateral orchiectomy, a prophylactic fixation of the contralateral testis was performed preferentially at 4-8 weeks after the initial intervention even though a simultaneous procedure is being increasingly used.

CONCLUSIONS

In approximately one fifth of registered patients, a testicular torsion is present causing the acute scrotum, and leading to an obligatory surgical intervention. Various causative differential diagnoses can be clarified by precise medical history and exact physical examination. Imaging procedures can be helpful in decision-finding. Finally, the clinical finding is crucial and decisive. If a testicular torsion cannot reliably be excluded by clinical investigation or imaging, an immediate surgical exploration of the testis has to be performed.

The role of bile acids in the neoplastic progression of Barrett's esophagus - a short representative overview

Barrett's esophagus (BE) is an intestinal metaplasia of the distal esophagus in which squamous cells are replaced by a columnar epithelium. It is considered as a premalignant lesion, which can lead to esophageal adenocarcinoma, a very aggressive type of cancer, and can often be found in patients with gastro-esophageal reflux disease (GERD). In spite of the widespread use of acid-suppressing therapy with proton pump inhibitors, the incidence of adenocarcinoma has been steadily rising during the last 30 years. So, it can strongly be suggested that refluxed material other than acid might contribute to the progression of cancer within Barrett's esophagus. Along with gastric acid, bile acids enter the esophagus during an episode of reflux, and bile acids may be important in carcinogenesis. In their refluxates, patients with GERD and BE show high concentrations of the hydrophobic bile salt deoxycholic acid (DCA), which has cytotoxic effects and is able to induce DNA damage in different cell types. Other bile acids, like the hydrophilic urodeoxycholic acid (UDCA), have been therapeutically used to treat cholestatic liver diseases and to prevent colon carcinoma. This article reviews the effects of bile acids and points out new perceptions in the progression of Barrett's-associated carcinogenesis.

Osteoinduction by combining bone morphogenetic protein (BMP)-2 with a bioactive novel nanocomposite

Objectives

There is increasing application of bone morphogenetic proteins (BMPs) owing to their role in promoting fracture healing and bone fusion. However, an optimal delivery system has yet to be identified. The aims of this study were to synthesise bioactive BMP-2, combine it with a novel α-tricalcium phosphate/poly(D,L-lactide-co-glycolide) (α-TCP/PLGA) nanocomposite and study its release from the composite.

Methods

BMP-2 was synthesised using an Escherichia coli expression system and purified. In vitro bioactivity was confirmed using C2C12 cells and an alkaline phosphatase assay. The modified solution-evaporation method was used to fabricate α-TCP/PLGA nanocomposite and this was characterised using X-ray diffraction and scanning electron microscopy. Functionalisation of α-TCP/PLGA nanocomposite by adsorption of BMP-2 was performed and release of BMP-2 was characterised using an enzyme-linked immunosorbent assay (ELISA).

Results

Alkaline phosphatase activity of C2C12 cells was increased by the presence of all BMP-2/nanocomposite discs compared with the presence of a blank disc (p = 0.0022), and increased with increasing incubation concentrations of BMP-2, showing successful adsorption and bioactivity of BMP-2. A burst release profile was observed for BMP-2 from the nanocomposite.

Conclusions

Functionalisation of α-TCP/PLGA with BMP-2 produced osteoinduction and was dose-dependent. This material therefore has potential application as an osteoinductive agent in regenerative medicine.

Aspects in the interdisciplinary decision-making for surgical intervention in ulcerative colitis and its complications

Ulcerative colitis (UC) is a chronic inflammation of the large bowel, predominantly affecting young adults of 20 to 30 years of age. Even though the majority of patients with limited and extensive UC can be managed medically, 20 to 30 % will require surgical intervention at some point in their life to gain control of the inflammatory process. The most common reason for urgent and emergency surgery is a lack of response to maximal medical inpatient therapy after five to ten days. Other indications include hemorrhage, free perforation, sepsis, and toxic megacolon. Procedure of choice for the majority of surgeons is open or laparoscopic subtotal colectomy and end ileostomy, with or without exteriorization of the rectal stump. The laparoscopic approach requires more time, but allows for faster return of bowel function and discharge from the hospital. Creation of a definite restoration in form of a J pouch should be delayed for at least three months. Indications for elective surgical intervention include cancer, dysplasia associated lesion or mass, and stricture. Preferably, the J pouch and Brooke ileostomy are performed in two stages, with a takedown of the ileostomy several months later. A single-stage operation is associated with increased anastomotic dehiscence, sepsis, and long-term pouch failure. The laparoscopic creation of a J pouch is largely dependent on the surgeon's experience, but results in a number of advantages, including faster return of bowel function, tolerance of diet, and discharge. Regardless of emergency, urgent, or elective surgical intervention, early involvement of a team of gastroenterologist, surgeon, nutritionist, and stoma nurse is essential in the management of severe UC to maximize a satisfactory patient outcome.

[Second primary malignancy among cancer survivors - epidemiology, prognosis and clinical relevance]

BACKGROUND

Rising population age and advances in treatment with improved survival from cancer have led to more frequent survivors of cancer treatment and subsequently to more patients with a second primary tumour. The consequences are presented in this overview.

METHOD

For the literature review, the Medline database (PubMed) was searched under the key words "multiple primary malignant tumors" and "(Neoplasms, second primary) AND "Neoplasms, Second Primary"[Mesh]". Primarily, publications in the last 7 years (2005 - 2011) were sought.

RESULTS

The prevalence of patients with second primary cancer is reported in various cancer registries with 6.6 % to 9 %. Here, the risk of developing new primary cancer in cancer survivors, depending on age, compared to the general population is increased at least by 20 %. Among childhood cancer survivors, the risk was even 3 - to 6-times higher than would have been expected in the general population. The incidence of second malignant neoplasms is crucially dependent on the prognosis of the first tumour. Fifteen years after initial diagnosis, in patients with prognostically unfavourable tumours such as pancreatic or gastric carcinoma, second primary malignancies are detected in less than 5 %. However, the cumulative incidence of all second cancers combined is approximately 15 % at 25 years in patients with colorectal or thyroid cancer.

CONCLUSION

Implications from these data arise for primary diagnostics which must look at cancers with frequent synchronous second malignancies for respective tumours before treatment. Examples are synchronous colorectal lesions in patients with colorectal carcinoma or synchronous cancers of the oral cavity and pharynx in patients with oesophageal carcinoma. Another consequence is a targeted follow-up of corresponding risk populations. This includes the screening for metachronous colorectal cancer, the exclusion of gastrointestinal second malignancies in patients with GIST, or the breast cancer screening in young female thyroid cancer survivors. Since radiotherapy increases the rate of second primary neoplasms, adjuvant radiotherapy should be well justified. Nevertheless, this is true only for young patients, mainly in childhood. The risk of a second cancer after irradiation in adults is small.