Weight Factor as a Parameter for Optimal Part Orientation in the L-PBF Printing Process Using Numerical Simulation.

The L-PBF process belongs to the most modern methods of manufacturing complex-shaped parts. It is used especially in the automotive, aviation industries, and in the consumer products industry as well. Numerical simulation in the powder sintering process is a means of optimizing time efficiency, accuracy and predicting future errors. It is one of the means to optimize the L-PBF process, which makes it possible to investigate the influence of individual parameters on additive manufacturing. This research makes it possible to predict the correct orientation of a part based on selected criteria, which are assigned a weighting factor in the form of parameters with which the simulation software Simufact Additive can work. Based on these, three possible orientations of the part were analysed with respect to the area of the supporting material, the volume of the supporting material, the number of voxels, and the building risk. Finally, the results of a simulation and the results of the tensile test were compared. From the results of the static tensile test, as well as from the results of the numerical simulation, it was found that better characteristics were achieved for the orientation of part no. 1 compared to orientation of part No. 3.

Simulation of 316L Stainless Steel Produced the Laser Powder Bed Fusion Process.

Additive manufacturing is increasingly being used in the production of parts of simple as well as complex shapes designed for various areas of industry. Prevention of errors in the production process is currently enabled using simulation tools that have the function of predicting possible errors and, at the same time, providing a set of information about the behaviour of the material in the metal additive manufacturing process. This paper discusses the simulation processes of 316L stainless steel produced using the laser powder bed fusion (L-PBF) process. Simulation of the printing process in the Simufact Additive simulation program made it possible to predict possible deformations and errors that could occur in the process of producing test samples. After analysing the final distortion already with compensation, the simulation values of maximum deviation -0.01 mm and minimum -0.13 mm were achieved.

Experimental Study of Steel-Aluminum Joints Made by RSW with Insert Element and Adhesive Bonding.

This work focuses on joining steel to aluminum alloy using a novel method of joining by resistance spot welding with an insert element based on anticorrosive steel in combination with adhesive bonding. The method aims to reduce the formation of brittle intermetallic compounds by using short welding times and a different chemical composition of the insert element. In the experiment, deep-drawing low-carbon steel, HSLA zinc-coated steel and precipitation-hardened aluminum alloy 6082 T6 were used. Two types of adhesives-one based on rubber and the other based on epoxy resin-were used for adhesive bonding, while the surfaces of the materials joined were treated with a unique adhesion-improving agent based on organosilanes. The surface treatment improved the chemical bonding between the substrate and adhesive. It was proved, that the use of an insert element in combination with adhesive bonding is only relevant for those adhesives that have a load capacity just below the yield strength of the substrates. For bonded joints with higher load capacities, plastic deformation of the substrates occurs, which is unacceptable, and thus, the overall contribution of the insert element to the load capacity of the joint becomes negligible. The results also show that the combination of the resistance spot welding of the insert element and adhesive bonding facilitates the joining process of galvanized and nongalvanized steels with aluminum alloys and suppresses the effect of brittle intermetallic phases by minimizing the joining area and welding time. It is possible to use the synergistic effect of insert element welding and adhesive bonding to achieve increased energy absorption of the joint under stress.

Predictive factors of endometriosis progression into ovarian cancer.

BACKGROUND: In recent years, the endometriosis has overcome a noteworthy renaissance in the recognition of its potential. In certain patients, a demonstrable malignant progression of ectopic foci leading to development of ovarian cancer is seen. The knowledge of endometriosis overthrow background into endometriosis associated ovarian cancer is of paramount importance for selection of patients at risk. The goal of the presented study was to review a malignant potential of the endometriosis and to specify predictive factors of endometriosis progression into ovarian cancer. Altogether 189 patients were included in the study. Conventional cytogenetics as well as measurement of transcriptional activity of CTNNB1 (ß-catenin) and HIF1A (HIF1-α) genes were prospectively studied in 60 endometriosis patients and 50 control group patients. The retrospective histopathological analysis was performed in 19 endometriosis associated ovarian cancer patients and 60 patients with histologically confirmed endometriosis. RESULTS: Five endometriosis patients showed a deviation from normal cytogenetics finding without affecting of their phenotype. In 6 cases of endometriosis associated ovarian cancer ectopic endometrium was not confirmed. The remaining 13 cases demonstrated either benign or atypical endometriosis or even structures of borderline carcinoma. Atypical endometriosis was histologically confirmed in 20% of 60 endometriosis patients. Determination of gene expression (CTNNB1, HIF1A) formed two subgroups. Transcriptionally incipient endometriosis subgroup with insignificant genes expression compared to control group. In transcriptionally evident endometriosis subgroup were genes expressions significantly higher compared to control group (p < 0.01) as well as transcriptionally incipient endometriosis subgroup (p < 0.05). CONCLUSIONS: Significant structural abnormalities of chromosomes are not included in genetic rigging of endometriosis patients. Atypical endometriosis represents a histopathologically detectable intermediate of endometriosis progression. Determination of genes expression CTNNB1 and HIF1A helps to allocate risk patients with endometriosis where more precise management is needed.

Ultimate Load-Carrying Ability of Rib-Stiffened 2024-T3 and 7075-T6 Aluminium Alloy Panels under Axial Compression.

Stringer-stiffened panels made of aluminium alloys are often used as structural elements in the aircraft industry. The load-carrying capacity of this type of structure cannot relieve the reduction in strength in the event of local buckling. In this paper, a method of fabrication of rib-stiffened panels made of EN AW-2024-T3 Alclad and EN AW-7075-T6 Alclad has been proposed using single point incremental forming. Panels made of sheets of different thickness and with different values of forming parameters were tested under the axial compression test. A digital image correlation (DIC)-based system was used to find the distribution of strain in the panels. The results of the axial compression tests revealed that the panels had two distinct buckling modes: (i) The panels buckled halfway up the panel height towards the rib, without any appreciable loss of rib stability, and (ii) the rib first lost stability at half its height with associated breakage, and then the panel was deflected in the opposite direction to the position of the rib. Different buckling modes can be associated with the character of transverse and longitudinal springback of panels resulting from local interaction of the rotating tool on the surface of the formed ribs.

Cryptorchidism and pesticides: Is there a connection?

INTRODUCTION: The aim of our study was to compare the level of the most common organophosphate metabolite, dimethyl phosphate, in urine of women giving birth to both boys with cryptorchidism (study group), and healthy boys (control group), as well as to compare the level of dimethyl phosphate in our population with the results obtained in other populations. MATERIAL AND METHODS: After the ethical approval we included thirty women in both study and control groups. All newborns were born between 38 and 42weeks' gestation. Urine samples were taken on 3rd postpartal day. Gas chromatography with flame photometric detection was used to analyze dimethyl phosphate in urine following the method of Wu et al. Statistical analysis was done using Mann-Whitney test to compare the results in the two groups. RESULTS: Geometric mean of dimethyl phosphate in the study group was 7.18±8.26µg/L and the creatinine-corrected level was 5.63±5.95µg/L, and in the control group, the values are 7.98±6.75µg/L and 6.15±7.01µg/L, respectively. There was not a statistically significant difference in levels of dimethyl phosphate between these two groups (p=0.72786). Dimethyl phosphate levels obtained in similar studies are: 14.4µg/L in Israel, 3.7µg/L in Palestine, 10.3µg/L in Jerusalem, 1.60µg/L in Caribbean islands and 2.60µg/L in Canada. CONCLUSIONS: Pregnant women in our country are exposed to organophosphate pesticides, but a correlation between the exposure to organophosphate pesticides and cryptorchidism was not found. LEVEL OF EVIDENCE: I. TYPE OF STUDY: Prognostic study, prospective study.

Protective effect of ischemic preconditioning on the jejunal graft mucosa injury during cold preservation.

Protection of intestinal graft mucosa during cold preservation is still an unmet need in clinical practice, thus affecting the success of transplantation. The present study investigates the ability of two ischemic preconditioning (IPC) procedures to limit cold preservation injury. Three groups of Sprague-Dawley rats were recruited (n=11 each) as follows: the short IPC (SIPC) performed through 4 cycles of mesenteric ischemia of 4 min each followed by 10 min of reperfusion, the long IPC (LIPC) obtained by 2 ischemic cycles of 12 min each followed by 10 min of reperfusion, and the control group (C) without IPC. Grafts were then stored in cold histidine-tryptophan-ketoglutarate solution and samples were taken at 0, 3, 6 and 9 h lasting preservation. Both IPC groups showed an advanced degree of preservation with delayed development of graft mucosa damage, mainly in the crypt region. At the beginning of preservation, the graft mucosa in both IPC groups showed lower degree of mucosal injury index (MII) by 50% in comparison with C group. Specifically, a significant improvement of MII was observed after 3h of preservation in the LIPC group (p<0.05) in comparison with untreated C grafts. Significant atrophy of the intestinal mucosa in C group was found after 3h of preservation (p<0.01), in SIPC group the progress of atrophy was delayed to 6 h (p<0.001), and in LIPC group only moderate decrease in that was found. A parallel increase of laminin expression with the MII rate after 6 and 9h of preservation in comparison with the level at time 0 was observed in all grafts (p<0.001 and p<0.01, respectively). In both IPC groups the apoptotic cell (AC) rate was significantly reduced at the beginning of cold preservation (p<0.05 both). Moreover, in both the SIPC and C groups, the progressive increase in MII rate connected with AC rate decrease was due to a predominance of necrosis. By contrast in the LIPC group, after an increase of nearly 50% in the AC rate at the 3rd hour, its level remained fairly constant during the further 6 h of preservation, thus probably preventing necrosis and improving graft viability.

Intestinal ischemia-reperfusion injury mediates expression of inflammatory cytokines in rats.

The small intestine is an organ with very well developed immunological activity, responsible for synthesis of specific inflammatory mediators that participate in causing the systemic inflammation that can occur after ischemia-reperfusion injury. The aim of our work was to study mRNA expression and protein concentration of inflammatory cytokines IL-10 and TNFα in the jejunal wall after intestinal ischemia-reperfusion injury (IRI). Cytokine concentration levels confirmed the direct effect of IRI on the inflammation process. The results refer to the changes in balance between pro-inflammatory and anti-inflammatory mediators and indicate that the predominant disturbance of homeostasis after intestinal IRI is present after 1 hour of reperfusion.

Vascular marker expression during the development of various types of gynaecological malignancy.

Clinical diagnosis of gynaecological malignancies is usually successful in the advanced stages of the tumour, and this has a major impact on the success of therapy. Therefore, in the last few years, cancer research has tried to identify and characterise new biochemical and molecular markers needed as predictive indicators for the diagnosis of cancer. Our aim has been to search the molecular changes in gene expression of death receptor 6, glycoprotein M6B (Gpm6B) and genes associated with tumours of the female genital system. After isolation of messenger RNA (mRNA), transcription of mRNA into the cDNA was performed. The quantification of gene expression changes was detected using the reverse transcription polymerase chain reaction (RT-PCR) method. Analysis at the protein level was performed using the Western blot method. In both methods, we used actin as a housekeeping gene for normalisation. Numerical quantification of changes in expression and in the level of the specific proteins was evaluated using the Data Syngene program. Significant changes in the levels of protein and mRNA expression were detected, mainly in the death receptor 6 (Dr6) gene of patients suffering from cancer of the corpus and cervix uteri and ovarian cancer, which also corresponded with the level of protein Dr6. At the level of transcription, a significant increase in the expression levels of mRNA for the Gpm6B gene was detected, which led to an increase in corresponding protein in the peripheral blood of patients with gynaecological tumours against the healthy control group. This article could help to find an adequate marker for clinical application that will enable more sensitive detection of the early stages of gynaecological malignancies from the peripheral blood of patients.

Breast carcinoma progression and tumour vascular markers related to apoptotic mechanisms.

BACKGROUND: In the last few years, the cancer research had tried to identify and characterize new biochemical and molecular pathways in which the inhibition induces prosurvival mechanisms. Our work describes the expression of two different members of apoptotic regulatory pathway and their relationship with a progression of breast carcinoma. MATERIALS AND METHODS: We compared expression of genes related to apoptosis (DR6 and Gpm6B) in the blood of patients suffering from stage I of breast cancer in different grades (I-IV), with healthy controls. After isolation of mRNA, transcription of mRNA into the cDNA was performed. The quantification of gene expression changes in DR6 and Gpm6B was detected by RT-PCR method. Analysis at the protein level was performed by the Western blot. RESULTS: In statistical analysis of Dr6 mRNA level changes we detected significant increase starting in Grading 1 (G1) and reached maximal level in G3.This expression on mRNA levels was similar to protein levels, which copy rising tendency with maximal value in G3. The results of Gpm6B were significantly lower. CONCLUSION: This result showed that antiapoptotic signalling during neovascularization is increased significantly. It would be advisable in the future to study the influence of cytostatic treatment on the expression of genes related to apoptotic pathways and their relationship with progression of breast cancer tumours.

Trehalase as a possible marker of intestinal ischemia--reperfusion injury.

BACKGROUND: Different pathological affections of the small intestine cause corresponding morphological and functional changes. The present study was aimed to assess intestinal trehalase activities during ischemia and following reperfusion, correlate them with the pathological changes and determine whether trehalase could be used as a biochemical marker of the intestinal ischemia, ischemia - reperfusion injury. MATERIAL AND METHODS: Wistar rats, randomly divided into 5 experimental groups (IR) (each n=15), were subjected to one hour mesenteric ischemia followed by 0, 1, 4, 12 and 24 hours of reperfusion. As a control group sham operated animals were used (n=15). The activity of trehalase was determined using an adapted Dahlqwist method. The range of intestinal injury was determined using histological (histopathological injury index and goblet cell quantification) and immunohistochemical (Ki67, InSitu TUNEL) methods. RESULTS: The highest activities of trehalase were recorded in the control group (C=4.42 ± 0.373 µmol/mg/h). The most altered intestinal histology detected in group IR1 was accompanied by the lowest trehalase activity (IR1=0.97 ± 0.209 µmol/mg/h; p < 0.001 C vs. IR1). Improved histological structure in the remaining reperfusion periods correlated with increase in trehalase activity. Almost normal mucosal histological architecture and 72% of the enzymatic activity were restored after 24 hours of reperfusion (IR24=3.20 ± 0.266 µmol/mg/h; p < 0.01 IR1 vs. IR24). CONCLUSION: The correlation between intestinal histology and trehalase activities during intestinal injury has been shown. Trehalase activity is closely associated with the status of the histological architecture of the small intestine.

Intravenous administration of tetramethylpyrazine reduces intestinal ischemia-reperfusion injury in rats.

Intestinal ischemia-reperfusion injury (IIRI) is a life-threatening condition requiring prompt medical intervention. Tetramethylpyrazine (TMP) is a biologically active alkaloid isolated from Ligusticum wallichii. Previously, it was shown that TMP causes vasodilatation and inhibition of platelet aggregation as well as exhibits significant antioxidant effects. Therefore, the aim of the present study was to evaluate possible therapeutic effects of TMP in the prevention of IIRI. Wistar rats (n = 80) were randomly divided into eight experimental groups and subjected to a 1 h occlusion of cranial mesenteric artery followed by 0, 1, 12, and 24 h period of reperfusion. Thirty minutes before the IIRI animals received either TMP (30 mg/kg, i.v.) or identical volume of saline. In addition, a control group of 10 animals was not exposed to IIRI. Intestine morphology was evaluated by using histopathological injury index examination (HII), goblet and Paneth cells quantification as well as by applying immunofluorescent methods such as InSitu TUNEL and caspase-3 positivity assessment. Here we showed that preconditioning with TMP prior IIRI decreases the grade of injury. Significant reduction of HII was detected in TMP pretreated groups after 0, 1, and 12 h of reperfusion where injury reduction up to 75% was found. Lower histopathological damage in preconditioned groups was accompanied with increased number of secretory epithelial cells and decreased number of apoptotic cells. These results demonstrate the protective effect of TMP on the small intestine mucosa, suggesting administration of TMP as a molecule for pharmacological intervention against IIRI.

Immunohistochemical study of jejunal graft mucosa cell populations during the initial adaptation phase in the host body in rats.

The character of the changes in cell populations within the jejunal graft mucosa during the initial adaptation phase in the host body was investigated. 24 adult male Wistar rats underwent intestinal heterotopic allotransplantation. Aorto-aortal and porto-caval anastomoses were performed using the end-to-side microsurgery technique. Graft tissues were compared to the intestinal tissues of the recipients. This study demonstrates that: (1) Distinct injury to the graft mucosa 1h after transplantation was accompanied by significant reduction in numbers of epithelial secretory cell populations. The injury was more intense in the mesenteric portion. Six hours after transplantation the graft mucosa was covered by a continuous epithelium, but the number of goblet and Paneth cells was found to be less than 30% of that in the recipient epithelium. (2) In comparison with recipients, myeloperoxidase-positive cell numbers increased significantly in the graft mucosa 1 h after transplantation. In the epithelial layer, denudation and destruction of villi was associated with a significant reduction in intraepithelial lymphocyte numbers. A significant decrease in mucosal mast cell numbers was detected 6 h after transplantation. They attained only 10% of the number found in the recipients. (3) Time-dependent changes in the graft mucosa revealed that CD163-positive cells increased significantly in the graft mucosa during 6 h after transplantation and reached the level found in the recipients. In contrast, the myeloperoxidase-positive cell population significantly decreased in the graft mucosa within the initial 6 h.

The relationship between morphology and disaccharidase activity in ischemia- reperfusion injured intestine.

BACKGROUND: Questions regarding functional markers characterizing injured intestines remain unanswered. Brush border disaccharidases are crucial for the functioning of the intestines. AIMS: The study was designed to assess changes in disaccharidase activity (DA) following intestinal injury and to compare them with morphological changes. METHODS: Wistar rats, randomly divided into six experimental groups (each n = 6), were subjected to different ischemic/reperfusion injury. One-hour mesenteric ischemia followed by reperfusion for 0, 1, 2, 4, 12 or 24 hours was induced. As a control group sham-operated animals were used (n = 6). Intestine morphology was evaluated using histopathological injury index (HII) and goblet cell (GC) detection. DA (sucrase and maltase) was studied in mucosal scrape or in entire intestinal wall samples. RESULTS: Moderate morphological damage (HII, GC) after mesenteric ischemia was detected. Deepening of the injury was found during reperfusion with a maximum after two hours. Improved morphology with longer reperfusion confirmed reversible damage with almost normal mucosal structure after 24 hours of reperfusion. Similar pattern was observed when DA was measured. The lowest activity was detected after 2 hours of reperfusion followed by increasing activity in the subsequent reperfusion periods. Physiological values after 24 hours of reperfusion were seen only in samples of entire intestinal wall. CONCLUSIONS: Significant changes in intestinal DA were observed after intestinal ischemia/reperfusion injury. A similar pattern was seen for morphological characteristics. Although based on microscopic survey the intestine seems to be fairly regenerated, some functional limitation is expected to persist.

Intestinal ischemia-reperfusion injury - the histopathological status of remote vital organs in acute and subacute phases.

BACKGROUND: Improvement of graft recovery and function follows current trends in intestinal transplantation; however, the alteration of remote organs (RO) predicts complicated systemic rejection. This study was conceived to describe the histopathological status of RO arising in both acute and subacute stages after intestinal ischemia-reperfusion injury (IIR) injury. MATERIAL/METHODS: Wistar rats (n=54) were divided into 7 experimental groups (n=7 each). All the animals were subjected to 60 min mesenteric ischemia and subsequently to reperfusion 2 h, 4 h, 24 h, 72 h, 10 days, 20 days and 30 days following the groups IR2 h, IR4 h, IR24 h, IR72 h, IR10 d, IR20 d and IR30 d. As a control group (S; n=5) sham-operated animals were used. Histopathological scores (HPS) were evaluated in biopsies of the right kidney, heart and colon ascendens. RESULTS: Statistically significant increase in kidney HPS was seen during reperfusion, with the peak in IR4h group (p<0.01). Thereafter, improved morphology was observed; however, increased HPS was seen even in the subacute stage, and significant deterioration of HPS up to 10 days of reperfusion was detected (p<0.05). Heart biopsies also showed statistically increased HPS value in IR4h group (p<0.05). Intact morphology of the colon was detected in all reperfusion periods. CONCLUSIONS: IIR causes a systemic reaction affecting RO. The peak of alteration for kidney and heart morphology was induced by 60 min of ischemia followed by 4 h of reperfusion. Thereafter, improved morphology was observed, although latent persistence of histopathological changes was seen even in the subacute stage. The colon remained intact during the whole experiment despite its anatomical proximity, confirming its high immunological capacity.

Mesenteric ischemia-reperfusion injury: specific impact on different cell populations within the jejunal wall in rats.

The progress of jejunal damage and recovery in the course of mesenteric ischemia-reperfusion injury in rats at different time periods was investigated. Mesenteric ischemia lasting 1h followed by 1h of reperfusion caused a significant disintegration of the mucosa, reduction of the muscular layer and diminution of the wall thickness. The loss of epithelium included enterocytes, goblet cells and Paneth cells. Paradoxically, increasing numbers of serotonin-producing cells and the beginning of regenerative processes, expressed by significantly higher proliferation, were recorded in the epithelium during this period. Disintegration of connective tissue and massive degranulation of serotonin-positive cells were found in the lamina propria. After 24h of reperfusion, restitution of the mucosa was found, expressed by normal villous morphology and re-epithelialization. However, some parameters were still significantly affected even more than in the acute phase of reperfusion. In the epithelium, decreased numbers of Paneth cells and increased population of serotonin-producing cells were found. The greatest proliferation of connective tissue cells and intensified reduction of the muscular layer were also detected in this reperfusion period. After 30 days of reperfusion, moderate damage remained, but only the increased number of Paneth cells and decreased number of serotonin-producing cells in the lamina propria were significant.

The outpatient utilization of non-steroidal anti-inflammatory drugs in South Backa District, Serbia.

OBJECTIVE: To evaluate the utilization of non-steroidal anti-inflammatory drugs (NSAIDs) in South Backa District (SBD), Serbia. SETTING: State-owned and private pharmacies in SBD, a northern district of Serbia, with 605,720 inhabitants (according to the 2008 census). METHOD: Data on the number of packages, size of packages, and retail price of NSAIDs (Anatomical Therapeutic Chemical (ATC) group M01A) from 1 January to 31 March 2008 were obtained from all state-owned and private pharmacies in SBD. This included NSAIDs bought without prescription and those issued by prescription (on the Health Insurance Companies List for Reimbursement). The number of defined daily doses/1000 inhabitants/day (DDD/1000 inh/day) was calculated. Within the DU90% (drug utilization 90%) segment, the proportion of high-, medium- and low-risk NSAIDs with respect to the risk of gastrointestinal (GI) bleeding was determined. Price/DDD was also calculated. MAIN OUTCOME MEASURE: Consumption of drugs expressed as DDD/1000 inh/day. RESULTS: The total consumption of NSAIDs over a 3-month period was 48.31 DDD/1000 inh/day. Only four drugs were within DU90%: diclofenac, ibuprofen, nimesulide and meloxicam (62.14, 19.87, 5.77, and 5.73% of total NSAID consumption, respectively). All dispensed NSAIDs within the DU90% segment except nimesulide (which was exclusively purchased without prescription) were nearly equally purchased without prescription and issued by prescription. The average price per DDD within the DU90% segment was 0.17 Euro/DDD, whereas it was 0.30 Euro/DDD for NSAIDs beyond the DU90% segment. The pattern of use of NSAIDs according to their GI risk showed that medium-risk diclofenac accounted for 66.45%, whereas low-risk ibuprofen was estimated to be 21.25% within the DU90% segment. CONCLUSION: Factors other than evidence-based medicine (such as poor health education in the past that led to long-lasting consequences on the cultural behaviour of the general population as well as on the prescribing habits of physicians) have a dominating impact on the use of NSAIDs in SBD. Targeted education from independent sources in the prescribing, dispensing and use of drugs is required to improve the quality of prescription and use of NSAIDs in Serbia.

Different ischemic preconditioning regimens affecting preservation injury of intestines.

Decreasing ischemia-reperfusion injury in intestinal transplantation is of paramount importance for improving graft recovery and function. This study explores the ability of two ischemic preconditioning (IPC) regimens to reduce preservation injury. Sprague-Dawley rats were divided into 3 groups (n = 11 each). In the controls (group C), intestinal grafts were harvested and preserved. IPC was performed either through 4 cycles of mesenteric ischemia of 4 min each followed by 10 min of reperfusion (group BIPC) or 2 ischemic cycles of 12 min each followed by 10 min of reperfusion (group LIPC). Grafts were stored in histidine-tryptophan-ketoglutarate, and samples were taken 0, 3, 6, 9, 12, 18, and 24 h after preservation. Preservation injury was scored using the Park/Chiu scale. Goblet cells (GC), enteroendocrine cells (EEC) and serotonin-producing EEC (SPEEC) were studied for evaluation of the graft conditions. Group C had the most advanced preservation injury followed by group BIPC. GC count was lowest in group C, followed by BIPC. Comparison between groups BIPC and LIPC showed superior parameters (preservation injury, GC, EEC, and SPEEC) in LIPC. In conclusion, an IPC regimen of 2 ischemic cycles of 12 min each followed by 10 min of reperfusion distinctly decreased the preservation injury of intestinal grafts compared with non-manipulated grafts.

Morphological and apoptotic changes in the intestinal mucosa and lung parenchyma after ischaemic/reperfusion injury of the jejunum.

Ischaemic/reperfusion (IR) injury of the small intestine may lead to the development of multiple organ failure. Little is known about the morphological changes occurring in the organs during the subacute course of this syndrome. The objective of this study was to observe histopathological features and the role of apoptosis in the jejunal mucosa and lung parenchyma after intestinal IR injury in a long-term experiment. Wistar rats (n = 36) were divided into 4 experimental groups (IR(10), IR(20), IR(30), S). Groups IR(10), IR(20) and IR(30) (each n = 10) were subjected to 1-hour ischaemia of the cranial mesenteric artery followed by 10, 20 or 30 days of reperfusion, respectively. The control group S (n = 6) was not subjected to ischaemia. The jejunal mucosa remained intact after all periods of reperfusion. Apoptotic cells were found particularly in the lamina propria, with the most significant difference observed in the IR(30) group (P < 0.01). The lung parenchyma had lower regenerative capacity, which was confirmed by a high index of histological damage after 30 days of reperfusion (P < 0.01) and by the presence of an increased number of apoptotic cells, especially in the pulmonary interstitium. The number of apoptotic cells was ten times higher than in the control group (P < 0.001).

Development of jejunal graft damage during intestinal transplantation.

BACKGROUND: Intestinal transplantation (ITx) represents difficult life-saving intervention reserved for patients with irreversible intestinal failure. A serious complication of ITx is jejunal graft (JG) damage. The aim of the study was to evaluate the development of JG damage during ITx and determine the share of pathological elements (mechanical manipulation, ischemia, reperfusion) in this damage. MATERIAL/METHODS: Male Wistar rats (n=60; 30 donors and 30 recipients) were used. The harvest of JG as well as heterotopic allotransplantation was performed using a technique adapted from Balaz et al. (2003). In all transplantations, three samples of JG were obtained: immediately after harvest (Sa1), after preservation (Sa2) and 60min after transplantation (Sa3). The samples were stained using the Hematoxylin&Eosin method and histopathological injury index (HII) was assessed using Park/Chiu classification. For detection and quantification of neuroendocrine cells (NECs) Singh's modification of the Masson-Hamperl argentaffin technique was used. RESULTS: The lowest level of HII was detected in Sa1=0.25+/-0.18; higher after preservation Sa2=1.42+/-0.38 and the highest HII was observed after transplantation Sa3=3.08+/-0.38. The percentage share of mechanical manipulation with the graft in jejunal damage during ITx was 8.11% (Sa1), the share of the ischemic element represented 37.98% (Sa2) and reperfusion had 53.91% of the share in jejunal damage (Sa3). The activity of NECs had sinusoidal character (Sa1=0.5+/-0.1; Sa2=1.4+/-0.0; Sa3=0.35+/-0.05). CONCLUSIONS: The development of JG damage during ITx had progressive character. Mechanical manipulation had minimal influence on jejunal damage. One third of damage was caused by the ischemic component and the largest impact on JG damage resulted from reperfusion.