Protective effect of hyperbaric oxygen treatment on rat intestinal mucosa after mesenteric ischaemia and reperfusion.

INTRODUCTION: Mesenteric ischaemia results from a lack of adequate blood flow to and oxygenation of the mesentery and intestines. The aim of the present study was to evaluate the effect of hyperbaric oxygen treatment (HBOT) on the healing process in intestinal mucosa of rats undergoing mesenteric ischaemia and reperfusion. METHODS: Thirty-two Wistar-Albino rats were divided into four groups of eight: 1) ischaemia/reperfusion (I/R); 2) sham operation; 3) I/R+HBOT started 6 hours after reperfusion; 4) I/R+HBOT started 12 hours after reperfusion. In the I/R groups, a vascular clamp was placed across the superior mesenteric artery to occlude arterial circulation for 60 minutes, followed by reperfusion. A dose of HBOT consisted of 100% oxygen breathing for 90 minutes at 2.5 atmospheres absolute pressure. Thirteen doses of HBOT were administered after ischaemia. The rats were sacrificed on the eighth day, and their intestinal tissues were harvested for histopathologic analysis. The tissue levels of catalase, malondialdehyde, and glutathione were determined. RESULTS: The histopathological scores (HSCORE) were consistent with macroscopic examinations. The scores were significantly higher (worse) in Group 1 compared to Group 2, Group 3, and Group 4 (for all comparisons, P < 0.05). Group 4's HSCORE was significantly higher than those of Group 2 and Group 3 (for both comparisons P < 0.05). Group 3's HSCOREs were only marginally higher than Group 2. Group 3 exhibited higher glutathione levels than Group 1 (P < 0.05). There were no significant differences across the groups with respect to malondialdehyde and catalase levels. CONCLUSION: A beneficial effect of HBOT was observed on oxidative stress and inflammation in acute mesenteric ischaemia-reperfusion.

Rosette-forming glioneuronal tumour of the fourth ventricle: case report and review of the literature.

Rosette-forming glioneuronal tumour (RGNT) of the fourth ventricle is one of the newly described primary tumours of the central nervous system. These tumours have two components of both neurocytic and glial areas but usually the glial component of the tumour predominates. They have biphasic cytoarchitecture with two elements; neurocytic rosettes resembling Homer-Wright rosettes, and astrocytic component resembling a pilocytic astrocytoma. They are low-grade tumours with lack of histopathological signs of malignancy. Here, clinical, magnetic resonance, computed tomography (CT) and pathological features of rosette-forming glioneuronal tumour of posterior fossa are presented. A 29-year-man was admitted with an acute neurological deterioration. A three ventricular hydrocephalus and a hypo-density around vermis in the posterior fossa were seen in his CT scans. He did well after an emergency external ventricular drainage. He had an elective operation and a mass that was reported to be a rosette-forming glioneuronal tumour of the fourth ventricle was excised.

Depletion of IL-2 receptor ß-positive cells protects from diabetes in non-obese diabetic mice.

The destruction of ß-cells in type 1 diabetes (T1D) progresses silently until only a minor fraction of the ß-cells remain. A late acting therapy leading to the prevention of further ß-cell killing would therefore be desirable. CD122, the ß chain of the interleukin-2 receptor, is highly expressed on natural killer (NK) cells and on a subpopulation of CD8 T cells. In this study, we have treated non-obese diabetic (NOD) mice with a depleting antibody against CD122. The treatment protected from diabetes, even when initiated just before disease onset. The degree of leukocyte infiltration into islets was unaffected by the treatment, further supporting effectiveness late in the disease process. It effectively removed all NK cells from the spleen, pancreas and pancreatic lymph nodes and abolished NK cell activity. Interestingly, despite the lack of CD122 expression on CD8 T cells in the pancreas, the overall frequency of CD8 cells decreased in this organ, whereas it was unaffected in the spleen. T cells were also still capable to respond against a foreign antigen. Conclusively, targeting of CD122(+) cells could represent a novel treatment strategy against T1D.

Investigation of the functional single-nucleotide polymorphisms in the BCRP transporter and susceptibility to colorectal cancer.

Breast cancer resistance protein (BCRP) protects tissues by actively transporting xenobiotics and their metabolites out of the cells. BCRP is expressed in the apical membrane of normal intestinal and colonic epithelium. The BCRP substrates include a number of structurally unrelated compounds, such as drugs, pesticides, carcinogens and endogenous compounds. Although the functional and common BCRP alleles, 34G>A and 421C>A, are shown to vary by ethnicity, their potential mechanism has not been adequately described with regards to affecting the susceptibility to colorectal cancer. The present study aimed to evaluate the effects of the BCRP variants on the susceptibility to colorectal cancer and to predict the individual responses to xenobiotics transferred by BCRP. BCRP 421C>A was significantly associated with the colorectal cancer risk (odds ratio, 16.12; P=0.005). These findings are the first results of BCRP allele distributions in the Turkish population and provide an understanding of the correlation between therapeutic approaches and etiology of colorectal cancer.

Associations between the functional polymorphisms in the ABCB1 transporter gene and colorectal cancer risk: a case-control study in Turkish population.

Colorectal cancer is among the most common cancer types in the world and its etiology involves the interaction of genetic and environmental factors. ABCB1 is highly expressed in the apical surface of colonic epithelial cells and acts as an efflux pump by transporting toxic endogenous substances, drugs and xenobiotics out of cells. ABCB1 polymorphisms may either change its protein expression or alter its function. Several studies have reported a possible association between ABCB1 variants and colorectal cancer, but no consistent conclusion has been arrived at. Therefore, we aimed to investigate the relationship between colorectal cancer and the functional common variants of ABCB1 (1236C > T; 2677G > T/A; 3435C > T). The distributions of the variants were determined in 103 patients with colorectal cancer and 150 healthy volunteers using polymerase chain reaction-restriction fragment length polymorphism methods. ABCB1 1236C > T was statistically significantly associated with colorectal cancer risk (OR, odd ratio = 1.91; 95% CI, confidence interval = 1.09-3.35; p = 0.034). In haplotype-based analysis, the proportion of individuals with the ABCB1 haplotype C1236-G2677-T3435 was significantly more common in patients than in controls (OR = 11.96; 95% CI = 2.59-55.32; p = 0.0004). We believe that the findings may be beneficial to the development of efficacious preventive strategies and therapies for colorectal cancer.

Influence of the functional polymorphisms in the organic anion transporting polypeptide 1B1 in the susceptibility to colorectal cancer.

Colorectal cancer is an important cause of death throughout the world, and its etiology involves the interaction of genetic and environmental factors. Transporter proteins are important in protecting organs from xenobiotics or toxins. Organic anion-transporting polypeptide 1B1 (OATP1B1) plays role in hepatic uptake and clearance of albumin-bound amphipathic organic compounds, including endogen substances, drugs, or xenobiotics. The SLCO1B1 gene expressing OATP1B1 is highly polymorphic. Up to now, SLCO1BI variants were the focus of several investigations on drug pharmacokinetics and cancer susceptibility. However, no information has been available on association between SLCO1B1 and colorectal cancer risk. Therefore, the study aims to investigate the relationship between colorectal cancer and the functional common variants of SLCO1B1 (388 A>G, -11187 G>A, 521 T>C) and to estimate the prevalence of these variants in the Turkish population. To that end, the distributions of the variants were determined in 100 patients with colorectal cancer and 150 healthy volunteers. SLCO1B1 521 T>C was statistically significantly associated with colorectal cancer risk (odds ratio [OR]=2.66; 95% confidence interval [CI]=1.31-5.41; p=0.0057). In haplotype-based analysis, SLCO1B1 haplotype G(388)-T(11187)-T(521) might be associated with the development of colorectal cancer (OR=4.26; 95% CI=1.62-11.16; p=0.002). We believe that the findings may be beneficial to the development of efficacious preventive strategies and therapies for colorectal cancer.

Polymorphisms in tumour necrosis factor alpha (TNFalpha) gene in patients with acute pancreatitis.

Proinflammatory cytokines, such as tumour necrosis factor alpha (TNFalpha), play fundamental roles in the pathogenesis of acute pancreatitis (AP). The aim of this study was to determine if polymorphisms in the TNFalpha gene are associated with AP. Two polymorphisms located in the promoter region (positions -308 and -238) in TNFalpha gene were determined using polymerase chain reaction- (PCR-) restriction fragment length polymorphism (RFLP) methods in 103 patients with AP and 92 healthy controls. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression analysis adjusted for age, sex, BMI and smoking. The frequencies of TNFalpha polymorphisms were both similar in patients with mild or severe pancreatitis, so were in pancreatitis patients and in controls. We suggest that both SNPs of TNFalpha are not genetic risk factor for AP susceptibility (OR = 1.63; 95% CI: 1.13-4.01 for TNFalpha(-308) and OR = 0.86; 95% CI: 0.75-1.77 for TNFalpha(-238)).

Increased diabetes development and decreased function of CD4+CD25+ Treg in the absence of a functional DAP12 adaptor protein.

Prior to the development of type 1 diabetes, T cells are primed in the pancreatic lymph nodes (PLN) where they interact with APC displaying beta cell-derived peptides. The details concerning the regulation of autoreactive T cell responses in the PLN are unclear. BDC2.5/B6g7 TCR transgenic mice represent a simplified model of type 1 diabetes, in which beta cell-specific CD4+ T cells expressing a diabetogenic transgenic TCR are first activated in the PLN and subsequently home to the pancreas where they mediate killing of beta cells. DNAX-activating protein of 12 kDa (DAP12) is an adaptor molecule carrying an ITAM motif. It associates with receptors on lymphoid and myeloid cells, including APC. We here show that introduction of a DAP12 null mutation in BDC2.5/B6g7 mice accelerated diabetes development and promoted an augmented activation state of PLN T cells expressing the transgenic TCR. Transferred BDC2.5 T cells proliferated more efficiently in the PLN of DAP12-deficient B6g7 recipients, which correlated with a decreased impact of co-transferred BDC2.5+CD4+CD25+ T cells. We propose that signaling through a DAP12-associated receptor on APC facilitates activation of Treg in the PLN and by this contributes to the maintenance of peripheral tolerance to beta cell-derived antigens.

CARD6 is interferon inducible but not involved in nucleotide-binding oligomerization domain protein signaling leading to NF-kappaB activation.

We have previously reported the cloning and characterization of CARD6, a caspase recruitment domain (CARD)-containing protein that is structurally related to the interferon (IFN)-inducible GTPases. CARD6 associates with microtubules and with receptor-interacting protein 2 (RIP2). RIP2 mediates NF-kappaB activation induced by the intracellular nucleotide-binding oligomerization domain (NOD) receptors that sense bacterial peptidoglycan. Here we report that the expression of CARD6 and RIP2 in bone marrow-derived macrophages is rapidly induced by beta IFN and gamma IFN. This IFN-induced upregulation of CARD6 is suppressed by lipopolysaccharide (LPS), in contrast to LPS's enhancement of IFN-induced RIP2 upregulation. We generated CARD6-deficient (CARD6(-/-)) mice and carried out extensive analyses of signaling pathways mediating innate and adaptive immune responses, including the NOD pathways, but did not detect any abnormalities. Moreover, CARD6(-/-) mice were just as susceptible as wild-type mice to infection by Salmonella enterica serovar Typhimurium, Listeria monocytogenes, Candida albicans, lymphocytic choriomeningitis virus, or mouse adenovirus type 1. Thus, although structural and in vitro analyses strongly suggest an important role for CARD6 in immune defense, the physiological function of CARD6 remains obscure.

RIP2 contributes to Nod signaling but is not essential for T cell proliferation, T helper differentiation or TLR responses.

Receptor-interacting protein 2 (RIP2), also known as CARDIAK and RICK, has been reported to play a role in both adaptive T cell responses and innate immunity as a mediator in TLR signaling and nucleotide-binding oligomerization domain (Nod) signaling. Because initial reports remain controversial, we have further examined both innate and adaptive immune responses in RIP2-deficient mice on the C57BL/6 background. Despite the up-regulation of RIP2 after T cell activation, we could not detect any defect in T cell proliferation or Th1/Th2 responses in RIP2-KO mice. Furthermore, we found that TLR responses in RIP2-deficient macrophages were normal. However, our analysis showed that Nod signaling was impaired in macrophages from RIP2-deficient mice. In conclusion, our data demonstrate a critical role for RIP2 in Nod signaling, while T cell proliferation, T helper differentiation and TLR responses were unaffected by the absence of RIP2.

Pregnancy-related spinal epidural capillary-cavernous haemangioma: magnetic resonance imaging and differential diagnosis.

Epidural haemangiomas are very rare tumours of the spine. Only a few case reports have been published and most of them were cavernous or capillary. To the best of our knowledge, we report the first case of a histologically confirmed epidural capillary-cavernous haemangioma of the thoracic spine presented in the MRI.

Bacterial brain abscesses: prognostic value of an imaging severity index.

AIM: To assess the correlation between imaging findings [computed tomography (CT) or magnetic resonance imaging (MRI)] and neurological status before and after the treatment of bacterial brain abscesses. MATERIALS AND METHODS: CT and MRI images of 96 patients with brain abscesses were retrospectively evaluated in terms of the number, location and size of lesions, and the presence and extent of perilesional oedema and midline shift. An imaging severity index (ISI) based on these different radiological parameters was calculated. Initial Glasgow Coma Scale (GCS) scores and ISI were assessed and the prognostic value of these two indices was calculated. The Pearson correlation test, Mann-Whitney test, Chi-square test, receiver-operating characteristic (ROC) analysis, together with comparison of ROC analyses and Fisher's exact test were used. RESULTS: There was a negative correlation between ISI and the initial GCS values: ISI increased as the GCS score decreased, indicating an inverse relationship (r=-0.51, p<0.0001). There was a significant difference between the ISI and GCS scores of patients with an adverse event compared with patients with good recovery. Outcome was significantly worse in patients with initial ISI over the calculated cut-off values of 8 points or GCS scores under the cut-off value of 13 points. CONCLUSION: ISI is a useful prognostic indicator for bacterial brain abscess patients and correlates strongly with the patient outcome for all parameters studied. ISI score had a better prognostic value than GCS.

Reduced antigen concentration and costimulatory blockade increase IFN-gamma secretion in naive CD8+ T cells.

CD8+ T cells are killer cells but also major producers of IFN-gamma. We have investigated the effects of peptide antigen titration and costimulatory blockade on IFN-gamma production and proliferation by naive CD8+ T cells. Mature dendritic cells (DC) pulsed with high amounts of agonist peptide triggered proliferation but little IFN-gamma secretion in individual T cells. In contrast, immature DC pulsed with similar amounts of peptide induced IFN-gamma secretion in a larger fraction of T cells but triggered less proliferation. Blocking B7.2 or lowering the amount of peptide on mature DC led to a response similar to that induced by immature DC, suggesting that differences in stimulatory strength were responsible for the different responses. Using splenic antigen-presenting cells (APC) we demonstrate that reducing the amount of peptide in combination with B7 blockage enhanced IFN-gamma secretion and decreased proliferation in naive CD8+ T cells in an additive way. Our data suggest that IFN-gamma secretion and proliferation are independently and inversely controlled by stimulatory strength in naive CD8+ T cells. This may enable CD8+ T cells to respond with IFN-gamma secretion to immature APC with few peptide ligands consistent with an early immunoregulatory role of CD8+ T cells.

Spectrum of cytokeratin-positive cells in the bone marrows of colorectal carcinoma patients.

BACKGROUND: Bone marrow micrometastases (BMM) is considered to be of interest as a prognostic marker in solid tumors. The use of density-gradient separated bone marrow (BM) aspirates does not allow proper morphological characterization of the cells. An alternative approach, using routinely processed clots of BM aspirates, is presented. MATERIALS AND METHODS: BM clots from 56 colorectal carcinoma patients were stained for cytokeratin (CK), p53 and Ki67 by double immunohistochemistry. Cytokeratin-positive (CK+) cells were immunohistochemically divided into three groups, viz. Group A (CK+ probably malignant epithelial cells), Group B (CK+ morphologically non-epithelial cells) and Group C (CK+ contaminating cells). RESULTS: Thirty-three patients (59%) had CK+ cells, of which 19 (58%) had Group A cells and 14 (42%) had Group B cells. Fourteen of the 56 patients had reactive BM, eight of these had Group A cells and 3 had Group B cells. Group B cells and Group C cells did not express p53. Group A cells were noted in 35% of patients with carcinomas of Dukes' stage C and in 41% of patients with metastatic disease. CONCLUSION: Double immunohistochemical staining of routinely processed BM clot, for p53 and Ki67 along with CK allows the sub-classification of CK+ cells.

Traumatic spinal cord injuries in Istanbul, Turkey. An epidemiological study.

This is a retrospective study conducted in all of the hospitals of Istanbul to survey new patients with a traumatic spinal cord injury (SCI) in 1992. In that year 152 new traumatic SCI were identified. The estimated annual incidence was 21 per million population. The male/female ratio was 3/1. The mean age was 33, being 34 for male patients and 31 for female patients. 72% of all patients were under the age of forty. The major causes of SCI were falls (43%) and car accidents (41%), followed by being struck by an object (7%), gunshot injury (5%), stab injury (2%). Fifty patients (33%) were tetraplegic and 102 (67%) paraplegic. Regarding the tetraplegic patients the commonest level was C5, in those who were paraplegic L1. There were no cases at levels C1, T1 or T2. The commonest associated injury was head trauma, followed by fractures of an extremity (or extremities). Severe head trauma, as a major cause of death, may obscure the actual incidence of SCI in this study. Accidental falls (exceeding road accidents) were mostly due to falls from buildings and accidents on work premises.