Two types of autologous cells in stricture development prevention after complete circular endoscopic dissection in minipig

INTRODUCTION

Complete circular endoscopic dissection (CED) is frequently accompanied with post-operative strictures formation in the esophagus. Various types of therapeutic approaches have recently been tested to prevent these strictures, e.g. cell therapy or stenting.

METHODS

Miniature pigs of Gottingen/Minnesota origin (n=10) were used in the study. First, we made the complete CED in the mid esophagus; next, the defect was left untreated or covered with mesenchymal stem cells (MSCs) or a mixture of MSCs and primary oral keratinocytes (pOKs) suspension without/with fully covered self-expandable metallic stent (SEMS). Consequently, we performed a control endoscopy with a stent removal, and necropsy was performed 17-36 days after cells application.

RESULTS

All CED procedures were completed successfully without serious complications. Although we were able to detect MSCs or pOKs in the post-CED defects up to the 36th day after transplantation, the combination of MSCs or MSCs/pOKs with or without SEMS application did not prevent post-CED strictures development. The mixture of MSCs and pOKs resulted in the formation of cellular aggregates, which were mainly observed in submucosa, and the post-CED defect was covered with collagen fibers containing a thin scarred epithelium, accompanied by various degrees of reconstruction and integrity.

CONCLUSION

Suspension application of autologous MSCs alone or in combination with pOKs with or without SEMS was ineffective in the prevention of strictures formation after complete CED. Nevertheless, the presence of MSCs or pOKs in the post-CED defect was confirmed even 5 weeks after transplantation.

Autologous transplantation of mesenchymal stem cells into the portal vein of the miniature pig; a preliminary experiment for NOTES approach

INTRODUCTION

There is evidence that mesenchymal stem cells (MSCs) could trans-differentiate into the liver cells in vitro and in vivo and thus may be used as an unfailing source for stem cell therapy of liver disease. Combination of MSCs (with or without their differentiation in vitro) and minimally invasive procedures as laparoscopy or Natural Orifice Transluminal Endoscopic Surgery (NOTES) represents a chance for many patients waiting for liver transplantation in vain.

METHODS

Over 30 millions of autologous MSCs at passage 3 were transplanted via the portal vein in an eight months old miniature pig. The deposition of transplanted cells in liver parenchyma was evaluated histologically and the trans-differential potential of CM-DiI labeled cells was assessed by expression of pig albumin using immunofluorescence.

RESULTS

Three weeks after transplantation we detected the labeled cells (solitary, small clusters) in all 10 samples (2 samples from each lobe) but no diffuse distribution in the samples. The localization of CM-DiI+ cells was predominantly observed around the portal triads. We also detected the localization of albumin signal in CM-DiI labeled cells.

CONCLUSION

The study results showed that the autologous MSCs (without additional hepatic differentiation in vitro) transplantation through the portal vein led to successful infiltration of intact miniature pig liver parenchyma with detectable in vivo trans-differentiation. NOTES as well as other newly developed surgical approaches in combination with cell therapy seem to be very promising for the treatment of hepatic diseases in near future.

Fixation of biomaterial to metallic stent and fixation of stents after circular endoscopic dissection in the esophagus on an animal model

INTRODUCTION

Complete circular endoscopic (submucosal) resection (CER) performed using the endoscopic submucosal dissection (ESD) technique is burdened with a high incidence of post-operative strictures in the esophagus. The most effective method of preventing them is not known so far; one of the possible methods is to prevent these strictures directly at the site of their formation by covering the defect with a stent. The aim of the study was to find a way to fix a selected biomaterial to a stent, and subsequently, to fix the stent at the CER site to prevent esophageal strictures in an animal model.

METHOD

Miniature piglets from the Czech Academy of Sciences breeding unit in Libechov (N=10) were used. Endoscopy was performed using a single-channel endoscope. First, we made two circular mucosal cuts spaced 5 cm apart in the middle esophagus and we performed the CER between them using the endoscopic submucosal dissection technique. After that, we covered the defect with a stent coated with biomaterial (Xe-Derma®) while we tried to prevent stent migration into the stomach. For stent fixation, we tested endo-clips (N=3), the Apollo endoscopic system (N=1) and the suspension technique using two polyamide threads (N=6) anchored in the nasal septum. We performed a control endoscopy, stent removal and subsequent autopsy after 12 weeks.

RESULTS

All procedures were completed successfully without serious complications or deaths. Although stents covered with Xe-Derma® were applied to the entire resection area, one case of mediastinitis and one paraesophageal abscess were found during autopsy, most likely due to microperforations caused during the procedure. Histological analysis showed that after contact with the biomaterial, re-epithelisation took place within one week of application to the resection area. Stent migration occurred in each case when the stent was attached to the esophageal wall by endo-clips or with the endoscopic suture system (Apollo). There was no stent dislocation in the cases where the stent was suspended by two polyamide threads.

CONCLUSION

We developed a technique of fixing biomaterial to the surface of metallic stents which we used to prevent the formation of esophageal strictures after CER. Distal suspension fixation of the stent with a polyamide thread proved to be the most effective, while fixations by endo-clips or with the endoscopic suture system were ineffective.Key words: benign esophageal strictures circular endoscopic resection endoscopic submucosal dissection complication prevention.

Impact of acute metabolic acidosis on the acid-base balance in follicular fluid and blood in dairy cattle

Acid-base balance is one of the most vigorously regulated variables of the body, including genital organs. Subacute ruminal acidosis is a common disturbance in dairy cows that disturbs several biochemical indices in the blood, cerebrospinal fluid, and urine. The possible negative effects of metabolic acidosis on the follicular fluid (FF) composition and, subsequently, on oocyte quality, are not fully elucidated. This study aimed to evaluate the changes in acid-base balance (ABB) in FF and blood during acute metabolic acidosis in dairy heifers. Ten Holstein heifers were stimulated with FSH in eight decreasing doses at 12-hour intervals (D0-D3). Acidosis was induced by oral administration of sucrose at 9 g/kg of body weight, dissolved in 10 L of warm tap water, at D3. Samples were collected from each cow at 0, 8, 12, 16, 24, 32, 40, and 48 hours after treatment. Samples of FF, obtained by transvaginal follicular aspiration, and peripheral blood were examined for ABB parameters: pH, pCO₂, pO₂, HCO₃^-, and base excess (BE). A significant decrease in pH, HCO₃^-, and BE values in the blood, as well as FF, occurred after sucrose treatment. The lowest pH values occurred in blood at 16 hours, and in FF at 24 hours, after treatment (7.30 ± 0.05 and 7.33 ± 0.05, respectively). The lowest HCO₃^- values in blood (18.75 ± 3.2 mmol/L) and FF (18.07 ± 2.84 mmol/L) occurred 24 hours after treatment, as did the lowest BE values (-6.61 ± 3.7 mmol/L and -7.53 ± 3.89 mmol/L, in blood and FF, respectively). Significant correlations for HCO₃^- (r = 0.928), BE (r = 0.946), pH (r = 0.889), and pCO₂ (r = 0.522) existed between blood and FF samples. The results demonstrated that metabolic acute acidosis substantially influences the characteristics of both serum and FF.

A comparison of two endoscopic closures: over-the-scope clip (OTSC) versus KING closure (endoloop + clips) in a randomized long-term experimental study

BACKGROUND

Both over-the-scope clip (OTSC) and KING (endoloop + clips) closures provide reliable and safe full-thickness endoscopic closure. Nevertheless, OTSC clip demonstrated significantly inferior histological healing in the short-term follow-up.

AIM

To compare OTSC versus KING closure of a perforation with regard to long-term effectiveness and macroscopic and histological quality of healing.

METHODS

We performed a randomized experimental study with 16 mini-pigs (mean weight 43.2 ± 11.2 kg). A standardized perforation was performed on the anterior sigmoid wall. KING closure (n = 8) was attained by approximation of an endoloop fixed to the margins of a perforation with endoclips. OTSC closure (n = 8) was performed by deploying OTSC (OVESCO) over the defect. Pigs underwent a control sigmoidoscopy 8 months after the closure to assess the macroscopic quality of healing. Then, autopsy was performed and the rectosigmoid was sent for histopathological assessment.

RESULTS

All closures were completed successfully without air leaks. The duration of closure was similar in both techniques (OTSC 17.8 ± 7.6 min vs. KING 19.6 ± 8.8 min). At autopsy, all KING closures (100 %) were healed with a flat scar without signs of leakage. Microscopically, no inflammatory changes were observed after KING closure. In the OTSC group, microscopic ulcers were present in two pigs (25 %), cryptal abscesses in three pigs (38 %) and significant neutrophil accumulation in all eight pigs (P < 0.01). Giant cell granulomas, dysplasia or abundant scarification was not observed in either group.

CONCLUSIONS

Both OTSC and KING closures offer a long-term reliable seal of a gastrointestinal perforation without stenosis or fistulas. KING closure provides long-term histologically superior healing.

[Transrectal hybrid NOTES versus laparoscopic cholecystectomy--a randomized prospective study in a large laboratory animal]

INTRODUCTION

NOTES (Natural Orifice Transluminal Endoscopic Surgery) technique was developed to achieve less invasive surgery with the aim to lower frequency of postoperative complications. Cholecystectomy is one of the most frequent elective surgical procedures and is relevant for evaluation of NOTES. The aim of the experimental study was to compare hybrid transrectal and laparoscopic cholecystectomy regarding feasibility and inflammatory response.

MATERIAL AND METHODS

A total of 20 pigs weighing 26-56 kg were randomized to laparoscopic or NOTES group. Transrectal approach (15-18 cm from anal edge) was created by needle knife, followed by balloon dilatation and two-channel endoscope was introduced into the abdominal cavity. Cystic artery and duct were clipped and dissected. After extirpation of the gall bladder the colostomy was closed by occlusion loop-and-clip (King' closure) technique. In the laparoscopic group, cholecystectomy was performed by three-port access. Blood samples for evaluation of inflammatory response markers (leukocytes, CRP, interleukin 6) were taken 0, 2nd, 7th and 30th postoperative day, when the experiment ended and pig was euthanized.

RESULTS

Two pigs were excluded (1 died early postoperatively for pneumonia, 1 for the rectal closure impossibility after it's laceration during of the gall bladder extirpation). Other pigs survived without complications. Procedure time was significantly longer in NOTES group (134 +/- 27 minutes versus 60 +/- 22 minutes, p < 0.05). White blood cells count and CRP level increased significantly in both groups 2nd and 7th postoperative day and then normalized. Differences between groups were not significant in any of the measured laboratory markers. Sectional finding of exudate and adhesions was comparable in both groups and all transrectal closures were healed. Small subhepatal abscess was found in one pig from NOTES group.

CONCLUSION

Transrectal hybrid cholecystectomy is a safe and feasible method with comparable inflammatory responses and longer operating time compared to laparoscopy. A novel loop-and-clip technique was verified as a safe and simple rectal closure.

[Minimal node affection in gastric carcinoma--pilote multicentric study results]

INTRODUCTION

Lymphadenectomy is an essential part of surgical treatment of gastric cancer. In the part of hematoxylin-eosin negative nodes, small foci of tumour cells (micrometastastasis and isolated tumour cells) can be found using immunostaing or RT-PCR. The aim of this study is to asses clinical and prognostic relevance of these findings.

MATERIAL AND METHODS

Multicenter, prospective, non-randomised clinical trial running in four Czech centres. All lymphatic nodes from patients after radical resection are stained using standard hematoxylin-eosin technique, all negative nodes are further processed with immunostaining employing cytokeratin antibody.

RESULTS

In the period of two years (1st January 2009 - 31st December 2010), 73 patients (100%) were included into the study from four Czech centers. All patients underwent radical resection for gastric cancer. Subtotal resection was performed in 33 patients (45%), total gastrectomy in the remaining 40 patients (55%). Total number of acquired lymphatic nodes (LN) reached 1245, average number of nodes per one patient was 17.3. H-E metastasis were disclosed in 364 LN (29%). All H-E negative nodes were further processed using immunohistochemical staining. Lymph node micrometastasis (MM) were discovered in 35 LN (3%), isolated tumour cells (ITC) in another 72 LN (6%). Clinical and prognostic relevance of lymph node MM and ITC was assessed based on the patients' survival data.

CONCLUSION

Preliminary results of this study indicate that presence of the lymph node MM and ITC in gastric cancer patients is not linked to worse oncological outcome. Based on our results we can conclude, that expensive, time consuming and technically demanding immunostaining technique could not yet be recommended as a routine part of histological investigation of lymphatic nodes.

Transcriptomic analysis of in vivo and in vitro produced bovine embryos revealed a developmental change in cullin 1 expression during maternal-to-embryonic transition

Pre-implantation embryos derived by in vitro fertilization differ in their developmental potential from embryos obtained in vivo. In order to characterize changes in gene expression profiles caused by in vitro culture environment, we employed microarray constructed from bovine oocyte and preimplantation embryo-specific cDNAs (BlueChip, Université Laval, Québec). The analysis revealed changes in the level of 134 transcripts between in vitro derived (cultured in COOK BVC/BVB media) and in vivo derived 4-cell stage embryos and 97 transcripts were differentially expressed between 8-cell stage in vitro and in vivo embryos. The expression profiles of 7 selected transcripts (BUB3, CUL1, FBL, NOLC1, PCAF, GABPA and CNOT4) were studied in detail. We have identified a switch from Cullin 1-like transcript variant 1 to Cullin 1 transcript variant 3 (UniGene IDs BT.36789 and BT.6490, respectively) expressions around the time of bovine major gene activation (8-cell stage). New fibrillarin protein was detected by immunofluorescence already in early 8-cell stage and this detection correlated with increased level of fibrillarin mRNA. The qRT-PCR analysis revealed significant differences in the level of BUB3, NOLC1, PCAF, GABPA and CNOT4 gene transcripts between in vivo derived (IVD) and in vitro produced (IVP) embryos in late 8-cell stage. The combination of these genes represents a suitable tool for addressing questions concerning normal IVD embryo development and can be potentially useful as a marker of embryo quality in future attempts to optimize in vitro culture conditions.

[Gastrointestinal stromal tumor--analysis of a patient group, literature overview]

INTRODUCTION

Gastrointestinal stromal tumors (GIST) are common mesenchymal gastrointestinal tumors, however, their incidence rate is low. The tumors originate from progenitor cells of interstitial cells of Cajal-gastrointestinal pacemaker cells, and the majority of them express c-Kit, a tyrosin kinase receptor. The aim of this study was to assess the GIST treatment in a group of patients and to compare the outcomes with literature data.

METHODS

The authors performed a retrospecitve analysis of all patients with histologically confirmed GISTs, who were operated in the 2nd Surgical Clinic of the Charles University Medical Faculty (LF UK) in Prague and in the Central Military Hospital Prague (UVN Praha), from 2003 to 2008.

RESULTS

During the five-year period, 13 patients underwent surgery in the Central Military Hospital Prague. The commonest tumor locations were the following: stomach (46%), small intestine (duodenum 23%, jejunum 23%, ileum 8%). R0 resection was performed in 12 subjects (92%). 10 patients (77%) remain in remission, in one patient, the disease is stabilized (8%), and in one patient, the disease progression and generalization has been recorded (8%).

CONCLUSION

Surgery is a standard treatment in localized tumors. Following radical resection, the patients benefit from adjacent treatment with tyrosin kinase inhibitors. Specific tyrosin kinase inhibitors have been shown effective in the treatment of metastatic and relapsing disorders. Primary surgical treatment in metastatic diseases remains a paliative option for patients with bleeding and obstruction.

[Pancreatectoduodenectomy for multiple duodenal diverticula. Case report]

The authors present a case report of a 61-years old female with 12 month history of deteriorative chronic pain located in epigastrium and propagating to her back, tabescence and upper dyspeptic syndrome. The first grade oesophagitis and duodenogastric reflux were verified endoscopically. There were adequate biliary tree as well as pancreatic duct and two high-volumed parapapillar diverticula and the third one in the region of D 3 depicted by ERCP and enteroclysis. Neither ultrasound nor computed tomography detected any pancreatic or hepatic pathology. All the alternatives of internal medical treatment resulted in no effect. The surgical treatment lied in performance of pylorus-saving pancreatoduodenectomy (Traverso-Longmire). Five months after operation the patient suffers from no ailments and prospers in general. The authors render an account of duodenal diverticula surgical treatment.

Volume of luteal tissue and concentration of serum progesterone in cows bearing homogeneous corpus luteum or corpus luteum with cavity

Ultrasonographical examinations of ovarian structures were performed in 27 inseminated cows at estrus days and on days 4, 9, 20, 25, 30, and 40 after ovulation. Three cows were used twice. Corpora lutea (CLs) with a cavity were compared with homogeneous CLs. in pregnant and nonpregnant cows. Diameters and volumes of CLs and cavities, as well as volumes of luteal tissue and concentrations of serum progesterone were determined. The volumes of the structures were calculated using a mathematical formula for a rotary ellipsoid. Homogeneous CLs and CLs with a cavity and their luteal tissue reached a maximum volume in nonpregnant and pregnant cows on day 9 after ovulation. At this time, CLs volumes were 7.52 +/- 3.14 (homogeneous CLs, n = 4) and 4.54 cm3 (CLs with a cavity, n = 1) in nonpregnant cows, and 6.05 +/- 1.71 (homogeneous CLs, n = 10) and 9.54 +/- 2.67 cm3 (CLs with a cavity, n = 15) in pregnant cows. The volumes of luteal tissue were 7.52 +/- 3.14 and 4.33 cm in nonpregnant cows and 6.05 +/- 1.71 and 8.62 +/- 3.46 cm3 in pregnant cows. Concentrations of progesterone in peripheral blood in pregnant cows bearing a homogeneous CLs or CLs with a cavity on day 9 were 3.15 +/- 0.69 ng ml-1 and 4.12 +/- 1.28 ng ml-1, respectively. The concentrations of progesterone were higher in pregnant cows in comparison with nonpregnant cows. CLs with a cavity in pregnant cows contained a higher volume of luteal tissue and higher secretory activity compared to homogeneous.

[Biochemical changes in the peripheral blood in cows 45 days after parturition]

Blood samples were collected from v. jugularis in five-day intervals from parturition to postpartum day 45 in the rearing conditions of a dairy cow production herd, consisting of 10 groups with 10 pluriparous cows each (crossbreds of Bohemian Pied cattle with Holstein-Friesian cattle). In blood serum the following activities were determined photometrically: aspartate aminotransferase--AST (0.36-0.47 mukat.l-1), gamma-glutamyl transferase--GMT (0.50-0.83 mukat.l-1) and lactate dehydrogenase--LD (7.22-9.10 mukat.l-1); their average values were at an almost constant level. Only did AST and GMT values decrease slightly from day 25 after parturition. The glucose average content on the day of parturition (4.07 mmol.l-1) steeply decreased to postpartum day 5 (2.79 mmol.l-1), and later on, it increased irregularly. The average values of total protein (66.7-73.2 g per 1) slightly increased from postpartum day 20. The values of urea (2.33-2.37 mmol.l-1) and bilirubin (3.49-5.15 mmol.l-1) did not show any larger changes in dependence on the time elapsing from parturition. The average content of creatinine (124-162 mmol.l-1) increased irregularly from postpartum day 15 and then it decreased. Cholesterol concentrations were gradually increasing from 2.58 mmol.l-1 on the day of parturition to 4.99 mmol.l-1 on day 45 after parturition. The average contents of calcium (2.20-2.66 mmol.l-1) and phosphorus (1.75-2.27 mmol.l-1) were irregularly increasing until day 20 after parturition. Also the average content of magnesium (0.86-1.15 mmol.l-1) rose from day 25 after parturition.

[Microscopic changes in intercaruncular endometrium and ovarian follicles in cows 35 days after parturition]

Surface epithelium of intercaruncular endometrium in pluriparous cows, crossbreds of Bohemian Pied cattle with Holstein-Friesian cattle, was not coherent until day 15 after parturition, with a variable height of cells (16-64 microns). Oedematous nature of lamina propria was subsiding gradually. From day 15 to day 20 after parturition the cell height of coherent surface epithelium and uterine glands became equable and stabilized (16-32 microns), and the lamina propria assumed its cellular nature with marked infiltration of polymorphonuclears and lymphocytes. Noticeable symptoms of atresia were demonstrated to occur more frequently in ovaries in the follicular population until day 15 after parturition. From day 10 to day 25 after parturition an increasing occurrence of luteinized follicles with diameters of maximally 3 mm was demonstrated.