Investigations on the life cycle and morphology of Tunga penetrans in Brazil

In the present study, the life cycle of Tunga penetrans was established in Wistar rats in the laboratory, and the morphology of the resulting developmental stages was studied by means of light and scanning electron microscopy. It was seen that the females enter at a nonfertilized stage through the skin of their hosts. Only there the copulation occurs, while females and males brought together in a Petri dish showed no interest in each other. In any way -- fertilized or not -- the females start about 6 days after penetration and hypertrophy with the ejection of eggs. While fertilized eggs proceed to development, the unfertilized ones remain arrested. The eggs are ovoid and measure about 600 x 320 mum. The larvae hatch from the eggs 1-6 days (mean 3-4) after ejection. Formation of larvae 2 took at least another day, while 4 up to 10 days more were needed until this larva starts pupation (mean 5-7 days). The formation of the adult fleas inside the puparium occurred within 9-15 days (with a maximum hatch at day 12). Adult female fleas having reached the skin of a host start blood sucking within 5 min and prepare to enter the skin. After 24 h, the flea stacked already with two thirds of its body inside the skin. After 40 h, the penetration was completed, and feeding and hypertrophical enlargement started, which was completed on day 6, when eggs became ejected. When studying the morphology of the fleas obtained from different hosts, slight variations were seen, which, however, are not significant for a species separation but may be an indication of the presence of different strains/races or the beginning of such a formation.

A primary peritoneal pseudomyxoma peritonei arising from the Mullerian tissue: a case report

A primary Pseudomyxoma Peritonei is uncommon. For a long time, ovaries, colon and appendix were proposed like a site origin of these enigmatic lesions. Recent publications show that the majority of cases are due to a rupture of appendicle adenoma. We report a case of a pseudomyxoma peritonei arising in an elderly patient with a previous medical history of appendectomy undergone in infancy. The pseudomyxoma was misdiagnosed as an abdominal abscess related to colitis. In our opinion, metaplasia of the Müllerian system is a possible source of a primary peritoneal pseudomyxoma.

Perineal lipoma in a newborn boy--a case report

We report the case of a newborn presenting with a pediculated mass arising from the anal margin. Antenatal sonogram and magnetic resonance imaging were unable to diagnose the precise nature of the lesion. Sacrococcygeal teratoma, an enterogenous cyst, a polyp, a prolapse or other perineal tumors were all proposed as possible entities. At birth, no other anatomic anomaly than this homogenous 2 cm para-anal lesion was seen. Excision of the mass was performed under general anesthesia. The postoperative histological exam showed mature fat cells. Reviewing the literature, there have been few previously reported cases of congenital perineal lipoma. It is a rare, benign and easy-to-treat condition that can be evocated by morphological sonography or magnetic resonance imaging (MRI).

Chemokine receptor CCR5 deficiency exacerbates cerulein-induced acute pancreatitis in mice

Acute pancreatitis (AP) is an inflammatory disease involving the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands [the CC chemokines CCL3/MIP-1alpha, CCL4/MIP-1beta, and CCL5/regulated upon activation, normal T cell expressed and secreted (RANTES)] regulate leukocyte chemotaxis and activation, we investigated the expression of CCR5 ligands and the role of CCR5 and its ligands in experimental AP in mice. AP was induced by hourly intraperitoneal injections of cerulein in CCR5-deficient (CCR5(-/-)) or wild-type (WT) mice. Induction of AP by cerulein resulted in an early increase of pancreatic CCL2, CCL3, and CCL4 mRNA expression, whereas CCL5 mRNA expression occurred later. CCR5(-/-) mice developed a more severe pancreatic injury than WT mice during cerulein-induced AP, as assessed by a more pronounced increase in serum amylase and lipase levels and by more severe pancreatic edema, inflammatory infiltrates (mainly neutrophils), and necrosis. CCR5(-/-) mice also exhibited increased production of CCL2/MCP-1, CCL3/MIP-1alpha, and CCL4/MIP-1beta during the course of cerulein-induced AP. In vivo simultaneous neutralization of CC chemokines with monoclonal antibodies in CCR5(-/-) mice reduced the severity of cerulein-induced AP, indicating a role of CC chemokines in exacerbating the course of AP in the absence of CCR5. Moreover, simultaneous neutralization of CCR5 ligands in WT mice also reduced the severity of cerulein-induced AP. In conclusion, lack of the chemokine receptor CCR5 exacerbates experimental cerulein-induced AP and leads to increased levels of CC chemokines and a more pronounced pancreatic inflammatory infiltrate, suggesting that CCR5 expression can modulate severity of AP.

Differential liver sensitization to toll-like receptor pathways in mice with alcoholic fatty liver

Gut-derived, endotoxin-mediated hepatocellular damage has been postulated to play a crucial role in the pathogenesis of alcohol-induced liver injury in rodents. Endotoxins induce production of tumor necrosis factor alpha (TNF-alpha) by Kupffer cells via Toll-like receptor (TLR) 4 and contribute to liver injury. This study addressed the contribution of other TLRs and ligands to alcoholic fatty liver. C57Bl6/J mice were fed a modified Lieber-DeCarli diet. Serum aminotransferase measurements, histological analysis, and quantification of liver TNF-alpha and TLR1-9 messenger RNA (mRNA) were performed. The effect of TLR ligands on liver injury was assessed in vivo. Neomycin and metronidazole or diphenyleneiodonium sulfate (DPI) were administered to evaluate the role of gut bacteria and NADPH oxidase activity, respectively, in hepatic TLR expression. Enteral ethanol (EtOH) exposure induced steatosis and increased liver weight, aminotransferase levels, and expression of TLR1, 2, 4, 6, 7, 8, and 9 liver mRNA. Injection of lipoteichoic acid, peptidoglycan (PGN), lipopolysaccharide (LPS), loxoribine, and oligonudeotide containing CpG (ISS-ODN) increased TNF-alpha mRNA expression more in the livers of EtOH-fed mice than in control mice. PGN, LPS, flagellin, and ISS-ODN induced liver inflammatory infiltrate in EtOH-fed mice but not control mice. Addition of antibiotics reduced the severity of alcoholic fatty liver without affecting TLR expression, whereas daily DPI injections reduced the EtOH-mediated upregulation of TLR2, 4, 6, and 9 mRNA. In conclusion, EtOH-fed mice exhibited an oxidative stress dependent on upregulation of multiple TLRs in the liver and are sensitive to liver inflammation induced by multiple bacterial products recognized by TLRs.

Supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas are characterized by a differential expression of S100 proteins

The levels of expression of the S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B proteins were immunohistochemically assayed and quantitatively determined in a series of 95 astrocytic tumors including 26 World Health Organization (WHO) grade I (pilocytic astrocytomas), 23 WHO grade II (astrocytomas), 25 WHO grade III (anaplastic astrocytomas) and 21 WHO grade IV (glioblastomas) cases. The level of the immunohistochemical expression of the S100 proteins was quantitatively determined in the solid tumor tissue (tumor mass). In addition twenty blood vessel walls and their corresponding perivascular tumor astrocytes were also immunohistochemically assayed for 10 cases chosen at random from each of the four histopathological groups. The data showed modifications in the level of S100A3 protein expression; these modifications clearly identified the pilocytic astrocytomas from WHO grade II-IV astrocytic tumors as a distinct biological group. Modifications in the level of S100A6 protein expression enabled a clear distinction to be made between low (WHO grade I and II) and high (WHO grade III and IV) grade astrocytic tumors. Very significant modifications occurred in the level of S100A1 protein expression (and, to a lesser extent, in their of the S100A4 and S100B proteins) in relation to the increasing levels of malignancy. While the S100A5 protein was significantly expressed in all the astrocytic tumors (but without any significant modifications in the levels of malignancy), the S100A2 protein was never expressed in these tumors. These data thus indicate that several S100 proteins play major biological roles in human astrocytic tumors.

Improving morphology-based malignancy grading schemes in astrocytic tumors by means of computer-assisted techniques

We propose an original methodology which improves the accuracy of the prognostic values associated with conventional morphologically-based classifications in supratentorial astrocytic tumors in the adult. This methodology may well help neuropathologists, who must determine the aggressiveness of astrocytic tumors on the basis of morphological criteria. The proposed methodology comprises two distinct steps, i.e. i) the production of descriptive quantitative variables (related to DNA ploidy level and morphonuclear aspects) by means of computer-assisted microscopy and ii) data analysis based on an artificial intelligence-related method, i.e. the decision tree approach. Three prognostic problems were considered on a series of 250 astrocytic tumors including 39 astrocytomas (AST), 47 anaplastic astrocytomas (ANA) and 164 glioblastomas (GBM) identified in accordance with the WHO classification. These three problems concern i) variations in the aggressiveness level of the high-grade tumors (ANA and GBM), ii) the detection of the aggressive as opposed to the less aggressive low-grade astrocytomas (AST), and iii) the detection of the aggressive as opposed to the less aggressive anaplastic astrocytomas (ANA). Our results show that the proposed computer-aided methodology improves conventional prognosis based on conventional morphologically-based classifications. In particular, this methodology enables some reference points to be established on the biological continuum according to the sequence AST-->ANA-->GBM.

Human galectin-2: expression profiling by RT-PCR/immunohistochemistry and its introduction as a histochemical tool for ligand localization

Sugar-encoded information of glyco-conjugates is translated into cellular responses by endogenous lectins. Galectins stand out against other lectin families due to their wide range of functions including cell adhesion, tissue invasion or growth regulation exerted at extracellular, membrane, cytoplasmic and nuclear sites. This remarkable versatility warrants close scrutiny of their emerging network, in this study with focus on homodimeric human galectin-2. We first detected presence of specific mRNA in various tissue types by processing post mortem and surgical specimens by RT-PCR protocols. Overlap of gene expression was noted with proto-type galectins-1 and -7 and also family members from the other two subgroups. To monitor expression on the level of protein a polyclonal anti-galectin-2 antibody was raised. Immunopositivity was semi-quantitatively assessed in sections of 209 human samples establishing an array both of normal tissues and samples with inflammation or benign/malignant growth. In general, positivity was predominantly epithelial without restriction of staining to certain tissue types, as fittingly indicated by our RT-PCR analysis. Staining was not limited to the cytoplasm but also included nuclear sites. To examine the suitability of the labeled lectin as a histochemical probe we biotinylated galectin-2 under activity-preserving conditions and introduced it to tissue profiling. Specific cytoplasmic staining proved the validity of the concept. Our results encourage systematic histopathologic studies by immuno- and lectin histochemistry, especially by adding galectin-2 as study object to galectin fingerprinting which has already yielded prognostic information on galectins-1, -3, -4 and -8 and hereby contributed to define functional overlap/divergence in this lectin family.

Clinical implication of immunohistochemical markers

The role of the pathologist is to establish accurate diagnosis more and more with the help of complementary techniques. At present immunohistochemical expression of some diagnostic and prognostic factors may possibly predict the response to specific therapies. We focus here on the expression of three of these markers: epidermal growth factor receptor which overexpression is correlated with aggressive tumoral behaviour and with the possibility of a targeted therapy, cytokeratins 7 and 20 with their diagnostic implication in carcinomatous differentiation, and we close this review with the identification of markers related to hereditary non-polyposis colorectal cancer involving microsatellite instability.

Correlation Between the Response to Cetuximab Alone or in Combination With Irinotecan and the Activated/Phosphorylated Epidermal Growth Factor Receptor in Metastatic Colorectal Cancer

Despite staining positive for the epidermal growth factor receptor (EGFR), a significant number of EGFR-expressing colorectal cancers are resistant to cetuximab, a chimeric monoclonal antibody directed against EGFR. Activation of EGFR through the autophosphorylation of its tyrosine residues stimulates different signaling downstream pathways and may reflect the level of receptor utilization by the tumor. This study investigated activated/phosphorylated EGFR (pEGFR) in 23 patients with EGFR-positive metastatic colorectal cancer refractory to irinotecan and treated with cetuximab, alone or in combination with irinotecan. Seven patients received cetuximab, and 16 patients received cetuximab plus irinotecan. Among the 23 patients, six (26%) had a partial response, 10 (44%) had stable disease, and seven (30%) had progressive disease. Median duration of disease control (partial response + stable disease) was 6 months. Nineteen out of 20 EGFR-positive tumors (95%) stained positive for pEGFR and had a median pEGFR immunohistochemical score of 5. Disease control rates differed between patients with a pEGFR immunohistochemical score >or= 7 (7/7, 100%) and less than 7 (7/13, 53.8%), showing a trend toward higher disease control in patients with high levels of pEGFR (>or= 7) who were treated with cetuximab with or without irinotecan (P = .05).

Regulatory Role of Host CD8+ T Lymphocytes in Experimental Graft-versus-Host Disease across a Single Major Histocompatibility Complex Class II Incompatibility

BACKGROUND

CD8+ T cells are known to regulate type 2 helper T cell (Th2) alloreactive immune responses but their mode of activation is unclear. We investigated the role of host CD8+ T cells in experimental Th2-type graft-versus-host disease (GVHD) where donor/recipient disparity is restricted to a single major histocompatibility complex (MHC) class II antigen.

METHODS

Immunoglobulin (Ig) E serum levels, eosinophilia and lymphoid tissue hyperplasia were compared after injection of bm12 CD4+ T cells in either wild-type or CD8+ T cell-deficient (CD8-/-) C57BL/6 mice. In vitro, we explored effects of the addition of CD8+ T cells from wild-type or IFN-gamma-/- mice in mixed leukocyte cultures prepared with beta2 microglobulin-deficient (beta2m-/-) CD4+ T cells as responders or beta2m dendritic cells as stimulators.

RESULTS

HyperIgE resolved after 3 weeks in wild-type hosts whereas it persisted for 6 weeks in CD8-/- hosts. Eosinophil infiltrates in lymph nodes were significantly enhanced in CD8-/- hosts. Increased serum levels of IL-5 and IL-13 in CD8-/- hosts confirmed the enhancement of Th2-type responses in the context of recipient CD8+ T cell deficiency. Hyperplasia of lymph nodes and spleen were similar in both groups, as well as in vivo proliferation of donor CD4+ T cells. In vitro, CD8+ T cell regulation of the alloreactive Th2 response depended on their production of IFN-gamma and did not require expression of beta2m on CD4+ T cells or antigen-presenting cells.

CONCLUSIONS

Host CD8+ T cells regulate alloreactive Th2 responses during graft-versus-host disease through an IFN-gamma dependent pathway, independently of the recognition of beta2m-associated MHC class I molecules.

The role of exogenous carbon monoxide in the recovery of post-ischemic cardiac function in buffer perfused isolated rat hearts

Isolated rat hearts were perfused for 10 min with oxygenated buffer and equilibrated with carbon monoxide (CO) of 0.001% and 0.01% before the induction of 30 min global ischemia followed by 120 min of reperfusion. These concentrations of CO significantly improved the post-ischemic recovery of coronary flow (CF), aortic flow (AF), and left ventricular developed pressure (LVDP). The improvement in recovery reflected in the reduction of infarct size and the incidence of reperfusion-induced ventricular fibrillation (VF). Thus, hearts subjected to 0.001% and 0.01% of CO exposure via the perfusion buffer, infarct size was reduced from the CO-free control value of 39% +/- 5% to 21% +/- 3% (*p<0.05) and 18% +/- 4% (*p<0.05), respectively. In the presence of 0.001% and 0.01% CO, the incidence of VF was also reduced from its control value of 92% to 17% (*p<0.05) and 17% (*p<0.05), respectively. Increasing the CO exposure to 0.1% in the buffer, all hearts showed VF combined with ventricular tachycardia or bradycardia and various rhythm disturbances indicating the direct toxic effects of CO on the myocardium. The results show that cardioprotective concentrations (0.01% and 0.001%) of exogenous CO related to an increase in cGMP levels and guanylate cyclase activities.

CCR5 deficiency exacerbates T-cell-mediated hepatitis in mice

Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A-induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5-/-) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5-/- mice also exhibited increased production of interleukin 4, tumor necrosis factor alpha, CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1+. In vivo neutralization of CCR5 ligands in CCR5-/- mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell-mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immuno-mediated liver injury.

Primary antibiotic resistance and effectiveness of Helicobacter pylori triple therapy in ulcero-inflammatory pathologies of the upper digestive tract

OBJECTIVES

To determine firstly, the rates of primary antimicrobial resistance for Helicobacter pylori-associated upper-digestive lesions in relation to the success rate of triple therapy; and secondly, the performance of HpSA stool antigen detection test for control of eradication after treatment.

METHODS

Prospective open study of 436 patients who underwent upper-digestive tract endoscopy with biopsies for histological examination and culture between January 1 and July 31, 2002 at a University hospital in Brussels, Belgium. The primary resistance to antibiotics of H. pylori isolates was determined by disc diffusion method. Seventy of 164 infected patients agreed to be included in the treatment study with standard triple therapy with amoxicillin + clarithromycin + omeprazole adjusted on the basis of antibiogram results. Control of eradication was tested by 14C-Urea breath test and H. pylori Stool Antigen test (HpSA test).

RESULTS

Primary resistance to clarithromycin and metronidazole was observed in 3% and 31% of the isolates, respectively. No primary resistance to amoxicillin and tetracycline was observed. By intention to treat analysis, H. pylori was eradicated in 56 (80%) patients included in the therapeutic study. Three (4%) patients were lost to follow-up. The rate of eradication failure was 20% (14/70), included 11 cases documented by a positive control test (14C-Urea breath test). In comparison with 14C-Urea breath test, the H. pylori Stool Antigen test showed a sensitivity of 100%, a specificity of 91%, PPV of 69%, and NPV of 100%.

CONCLUSION

Standard triple therapy achieved 80% bacterial eradication in this patient population with a low prevalence of H. pylori primary antibiotic resistance. Our data confirm that the H. pylori Stool Antigen test displays a diagnostic performance similar to the breath test for control of eradication.

Oesophageal tonsil of the chicken

The oesophageal tonsil of the chicken is a novel member of the mucosal-associated lymphoid tissue (MALT), which is located around the entrance of the proventriculus. It consists of 6 to 8 single units, which are surrounded by a thin fibrous capsule. Each one is organised around the bottom of the longitudinal folds of the oesophagus, and serves as a 'tonsillar crypt'. Stratified squamous epithelium is infiltrated by lymphoid cells, i.e. T cells, plasma cells, macrophages, and dendritic cells, but not B cells, to form lymphoepithelium (LE). In the LE vimentin-, MHC II- and ATPase-positive cells possibly represent Langerhans' cells, but the appearance of 74.3 positive cells in the LE is unusual, because the 74.3 monoclonal antibody (mAb) recognises chicken follicular dendritic cells in the germinal centre and medulla of the bursal follicles. The subepithelial lymphoid tissue is organised into T- and B-dependent regions, which are the interfollicular areas and the germinal centres, respectively. Existence of high-endothelial venules in the interfollicular region suggests an extensive cellular connection between the oesophageal tonsil and the other lymphoid organs. In the resting oesophagus the lumen is closed, but during swallowing a bolus the crypt opens and the lymphoepithelium can be exposed to undigested food, antigens, infectious agents and vaccines. The location of the oesophageal tonsil, cranial to the stomach, may provide this organ with a unique role as compared to the other parts of the MALT; namely, it may contribute to the replication of infectious bursal disease virus (IBDV) and/or the pathogenesis of infectious bursal disease.

The role of PET scan in the preoperative management of oesophageal cancer

AIM

The aim of this study was to evaluate the role of the 18F-FDG-PET in the preoperative evaluation of patients with oesophageal or gastro-oesophageal junction (GEJ) cancer and to define its impact on therapeutic management.

PATIENTS AND METHODS

This study included 58 patients with biopsy proven oesophageal or GEJ cancer who underwent PET in addition to the conventional diagnostic work-up. The sensitivity, specificity and accuracy of CT and PET were calculated for detection of tumour and distant metastases.

RESULTS

The sensitivity, specificity and accuracy of tumour detection were, respectively, 84, 100 and 84% for CT and 87, 100 and 87% for PET (p=ns). PET permitted detection of distant metastases, which were not seen on CT in seven patients. In two patients, a second primary tumour was detected on PET.

CONCLUSIONS

The sensitivity of PET for loco regional lymph nodes detection is low. The major clinical impact is the detection of distant metastases.

Wild-type p53 activates SAP expression in lymphoid cells

SAP is an adaptor molecule with one SH2 domain and it is expressed in activated T and NK cells, where it is required for the appropriate signaling from the SLAM family of surface receptors. Deleted or mutated SAP genes that encode functionally defective protein are associated with the X-linked lymphoproliferative disease (XLP). This primary immunodeficiency is characterized by extreme sensitivity to Epstein-Barr virus (EBV) infection, dysgammaglobulinemia and a high rate of lymphoma development. The vigorous T- and B-cell proliferation that follows EBV infection and the high incidence of lymphomas (30%) in XLP patients might reflect functional defects in cell cycle and/ or apoptosis control. Our experiments show that SAP is a target of p53. In Burkitt lymphoma (BL) lines transfected with a temperatur-sensitive (ts) p53, SAP mRNA and protein expression was dependent on wild-type (wt) p53. Activation of endogenous wt p53 in BLs and lymphoblastoid cell lines led to the induction of SAP and this was inhibited by the specific p53 inhibitor pifithrin-alpha. Cell lines that carried mutant p53 did not express SAP under similar conditions. Moreover, we have shown binding of wt p53 to the promoter region of SAP by ChIP assay. Our results suggest that SAP contributes to the execution of some p53 functions.

Evaluation of stool antigen detection for diagnosis of Helicobacter pylori infection in adults

OBJECTIVE

The aims of this study were to evaluate the performance of Helicobacter pylori stool antigen test in the diagnosis of H. pylori infection.

METHOD

The study included 63 out patients attending the ULB-Lothier Clinic between January 1 and July 31, 2002. They underwent an upper endoscopy, as well as biopsies for histological examination and for culture of H. pylori. Stool samples of these patients were collected either the day of the endoscopy or within 24 hours and tested for H. pylori antigen (HpSA Test)

RESULTS

The mean age of study patients included 29 men and 34 women was 51(+/- :16) years. H. pylori infection was detected in 29 cases (46 %) by culture and histology, and in 31 cases (49.2 %) by detection of the antigen in the feces. In 27 patients, all methods were positive whereas 5 in they provided discrepant results. Compared to the reference methods (culture and histology), the HpSA test had a sensitivity of 96.5% and a specificity of 91.2%. PPV of 90.3% and NPV of 96.8%.

CONCLUSION

The good correlation found between the results of the HpSA test and the methods based on endoscopy supports its use as an alternative to invasive methods of diagnosis of H. pylori infection and therapeutic follow-up.