The interplay of collagen IV,tumor necrosis factor-alpha,gelatinase B (matrix metalloprotease-9), and tissue inhibitor of metalloproteases-1 in the basal lamina regulates Sertoli cell-tight junction dynamics in the rat testis

During spermatogenesis, preleptotene and leptotene spermatocytes must translocate across the blood-testis barrier formed by inter-Sertoli cell-tight junctions (TJs) from the basal compartment of the seminiferous epithelium adjacent to the basement membrane to the adluminal compartment at stages VIII-IX for further development. Because of the close proximity between extracellular matrix (ECM) that constitutes the basement membrane and the blood-testis barrier, we sought to investigate the role of ECM in Sertoli cell TJ dynamics. When Sertoli cells were cultured in vitro to initiate the assembly of the Sertoli cell TJ-permeability barrier, the presence of an anticollagen IV antibody indeed perturbed the barrier. Because ECM is known to maintain a pool of cytokines and TNFalpha has been shown to regulate TJ dynamics in other epithelia, we investigated whether TNFalpha can regulate Sertoli cell TJ function via its effects on collagen alpha3(IV) and other proteins that maintain the homeostasis of ECM. As expected, recombinant TNFalpha perturbed the Sertoli cell TJ-barrier assembly in vitro dose dependently. TNFalpha also inhibited the timely induction of occludin, which is known to associate with the Sertoli cell TJ-barrier assembly. Furthermore, TNFalpha induced the expression of Sertoli cell collagen alpha3(IV), gelatinase B (matrix metalloprotease-9, MMP-9) and tissue inhibitor of metalloproteases-1 but not gelatinase A (matrix metalloprotease-2), and promoted the activation of pro-MMP-9. These results thus suggest that the activated MMP-9 induced by TNFalpha is used to cleave the existing collagen network in the ECM, thereby perturbing the TJ-barrier. This in turn creates a negative feedback that causes TNFalpha to induce collagen alpha3(IV) and tissue inhibitor of metalloproteases-1 expression so as to replenish the collagen network in the disrupted TJ-barrier and limit the activity of MMP-9. Taken collectively, these observations strengthen the notion that ECM is involved in the regulation of junction dynamics in addition to its structural role in the testis.     

Screening for oesophageal adenocarcinoma: an evaluation of a surveillance program for columnar metaplasia of the oesophagus

BACKGROUND: Screening patients with columnar metaplasia of the oesophagus for adenocarcinoma is controversial owing to the low cancer incidence and diverging opinions as to whether screening improves the prognosis of these patients. Our aim was to evaluate a screening program for adenocarcinoma in patients with columnar metaplasia in the oesophagus, with focus on cancer incidence and costs. METHODS: One hundred and ninety-nine patients with columnar metaplasia of the oesophagus were identified through an endoscopy database, and the original patient records were reviewed. RESULTS: The patients were followed up for 797 years in total and during this time were subjected to 1071 upper gastrointestinal endoscopies. During the screening period 5 patients presented with adenocarcinoma; thus the cancer-incidence was 1 in 159 patient-years. The cost of detecting one cancer was 294,950 SEK (US$ 37,815). However, only four of the five patients were suitable for oesophagectomy, and of these, one patient turned out to have an advanced cancer. All patients developing cancer had columnar metaplasia of the oesophagus longer than 3 cm and specialized columnar epithelium (intestinal metaplasia/Barrett oesophagus). CONCLUSIONS: Low cancer incidence, high costs, and the doubtful prognosis for the patients with identified cancer question the benefits and cost-effectiveness of cancer screening among patients with columnar metaplasia in the oesophagus.     

Interventional ERCP in patients with cholestasis. Degree of biliary bacterial colonization and antibiotic resistance]

Interventional ERCP in patients with cholestasis. Degree of biliary bacterial colonization and antibiotic resistance.Biliary obstruction together with bacterial colonization of the bile duct may lead to development of acute cholangitis. The aim of our prospective study was to investigate the presence and degree of biliary bacterial colonization by means of bile aspiration during ERCP in patients with biliary obstruction. Furthermore, we evaluated antibiotic therapy regimens, which would cover the bacterial species obtained by ERCP and subsequent culture in each patient. In addition, analysis of risk factors was performed that would predispose to the development of cholangitis.80 patients with clinical and laboratory evidence of biliary obstruction underwent ERCP with initial aspiration of bile via the cannulation catheter.This material was used to culture aerobic and anaerobic bacteria and determine the colony count/ml bile, followed by identification of each species and antibiotic resistance testing. The minimal inhibitory concentration for Levofloxacin, Ciprofloxacin, Piperacillin, Ampicillin, Ceftriaxone, Imipenem, Gentamycin und Metronidazole was determined. Immediately after the ERCP or if the body temperature (after ERCP) rose to > 38 degrees C blood cultures were obtained.In 45 (56 %) patients biliary colonization with bacteria could be identified (56 %). In 20 patients a single isolate was cultured, in 25 cases mixed infection was present. A total of 83 species were isolated. The most common bacteria were E. coli, Enterococcus and Klebsiella. 9.6 % of all isolates were obligatory anaerobes. In 9 of 80 patients bloodcultures tested positive for bacterial growth (rate of bacteremia: 11.3 %). 10 patients had acute cholangitis clinically before ERCP, 13 patients developed signs of infection after ERCP.Statistically significant factors contributing to the risk of infection were age of the patient, the clinical condition of the patient before ERCP and the biliary colony count.Patients with development of infection after ERCP showed a significantly higher incidence of bacterial colonization of the biliary tree and a higher colony count.In all bacterial species Imipenem (4.5 %) or Levofloxacin (2.2 %) exhibited the lowest rate of in-vitro resistance.Based on these data, the implementation of Levofloxacin in combination with anaerobic coverage is advantageous as a calculated therapy for patients with acute cholangitis.     

P-glycoprotein regulates blood-testis barrier dynamics via its effects on the occludin/zonula occludens 1 (ZO-1) protein complex mediated by focal adhesion kinase (FAK)

The blood-testis barrier (BTB), one of the tightest blood-tissue barriers in the mammalian body, creates an immune-privileged site for postmeiotic spermatid development to avoid the production of antibodies against spermatid-specific antigens, many of which express transiently during spermiogenesis and spermiation. However, the BTB undergoes extensive restructuring at stage VIII of the epithelial cycle to facilitate the transit of preleptotene spermatocytes and to prepare for meiosis. This action thus prompted us to investigate whether this stage can be a physiological window for the delivery of therapeutic and/or contraceptive drugs across the BTB to exert their effects at the immune-privileged site. Herein, we report findings that P-glycoprotein, an ATP-dependent efflux drug transporter and an integrated component of the occludin/zonula occludens 1 (ZO-1) adhesion complex at the BTB, structurally interacted with focal adhesion kinase (FAK), creating the occludin/ZO-1/FAK/P-glycoprotein regulatory complex. Interestingly, a knockdown of P-glycoprotein by RNAi was found to impede Sertoli cell BTB function, making the tight junction (TJ) barrier "leaky." This effect was mediated by changes in the protein phosphorylation status of occludin via the action of FAK, thereby affecting the endocytic vesicle-mediated protein trafficking events that destabilized the TJ barrier. However, the silencing of P-glycoprotein, although capable of impeding drug transport across the BTB and TJ permeability barrier function, was not able to induce the BTB to be "freely" permeable to adjudin. These findings indicate that P-glycoprotein is involved in BTB restructuring during spermatogenesis but that P-glycoprotein-mediated restructuring does not "open up" the BTB to make it freely permeable to drugs.     

Importance of Performing Transesophageal Echocardiography in Acute Stroke Patients older than Fifty

Background: The purpose of this study was to determine the value of transesophageal echocardiography (TEE) in determining the presence of cardiac manifestations that required anticoagulation in patients presenting with acute stroke. Methods: Of 626 consecutive stroke patients who underwent TEE, 188 patients with no obvious etiology for stroke were subcategorized according to age. TEE results were analyzed for cardiac findings suggestive of a cause for embolic stroke, including complex atheromas in the arch/ascending aorta, patent foramen ovale (PFO), atrial septal aneurysm (ASA), and intracavitary thrombi. Data were analyzed using Fisher's exact test. Results: Of 188 patients, 66% (125/188) were older than 50 years and 34% (63/188) were younger than 50 years. The incidence of complex atheroma was 12.8% (16/125) in patients older than 50 years as compared to 0% (0/63) in patients who were younger than 50 years (P = 0.002). In patients older than 50 years, findings that indicated a need for anticoagulation based on TEE results were found in 22.4% (28/125) (atheroma = 16, PFO = 12, ASA = 5, thrombus = 3, PFO + ASA = 1) compared to 14.3% (9/63) (atheroma = 0, PFO = 5, ASA = 2, thrombus = 2, PFO + ASA = 1) in patients younger than 50 years. Conclusions: TEE plays an important role in suspected embolic stroke patients of all age groups. Due to the higher incidence of complex atheromas in patients older than 50 years of age, TEE might be of added importance in identifying the candidates who may benefit from anticoagulation. (Echocardiography 2010;27:1086‐1092)     

Clinical and imaging findings in children with non-syndromic lambdoid synostosis

True unilateral lambdoid synostosis is a very rare type of craniosynostosis. Patients present with unilateral posterior plagiocephaly. The differentiation between frequent, simple positional (deformational) posterior plagiocephaly and lambdoid synostosis is not easy and to date subject of controversy. Accurate and early diagnosis is important, because treatment is different. Simple positional plagiocephaly responds to conservative treatment, but craniosynostosis may require neurosurgical intervention. We analyzed clinical presentation of five patients in whom non-syndromic lambdoid synostosis was confirmed by CT imaging, in one additionally by high-resolution ultrasound, and finally neurosurgical intervention. However, clinical inspection alone did not reliably identify infants with lambdoid synostosis. Conclusion: Diagnosis of lambdoid synostosis is not always possible based on clinical inspection alone. To confirm the diagnosis imaging is recommended. There is evidence that high-resolution ultrasound can be used first-line in the future.     

Efficacy of intranasal naloxone as a needleless alternative for treatment of opioid overdose in the prehospital setting

Prehospital providers are at increased risk for blood-borne exposure and disease due to the nature of their environment. The use if intranasal (i.n.) medications in high-risk populations may limit this risk of exposure. To determine the efficacy of i.n. naloxone in the treatment of suspected opiate overdose patients in the prehospital setting, a prospective, nonrandomized trial of administering i.n. naloxone by paramedics to patients with suspected opiate overdoses over a 6-month period was performed. All adult patients encountered in the prehospital setting as suspected opiate overdose (OD), found down (FD), or with altered mental status (AMS) who met the criteria for naloxone administration were included in the study. i.n. naloxone (2 mg) was administered immediately upon patient contact and before i.v. insertion and administration of i.v. naloxone (2 mg). Patients were then treated by EMS protocol. The main outcome measures were: time of i.n. naloxone administration, time of i.v. naloxone administration, time of appropriate patient response as reported by paramedics. Ninety-five patients received i.n. naloxone and were included in the study. A total of 52 patients responded to naloxone by either i.n. or i.v., with 43 (83%) responding to i.n. naloxone alone. Seven patients (16%) in this group required further doses of i.v. naloxone. In conclusion, i.n. naloxone is a novel alternative method for drug administration in high-risk patients in the prehospital setting with good overall effectiveness. The use of this route is further discussed in relation to efficacy of treatment and minimizing the risk of blood-borne exposures to EMS personnel.     

Differential treatment and early outcome in the interventional endoscopic management of pancreatic pseudocysts in 27 patients

AIM: Pancreatic pseudocysts (PPC) as a complication of pancreatitis are approached only in the case of abdominal pain, infection, bleeding, and compression onto the gastrointestinal tract or biliary tree. METHODS: From 02/01/2002 to 05/31/2004, all con-secutive patients with symptomatic PPC who underwent an interventional endoscopic approach were evaluated in this pilot case-series study: Group (Gr.) I-Primary percutaneous (external), ultrasound-guided drainage. Gr. II-Primary EUS-guided cystogastrostomy. Gr. III-EUS-guid-ed cystogastrostomy including intracystic necrosectomy. RESULTS: (="follow up": n = 27): Gr. I (n = 9; 33.3%): No complaints (n = 3); change of an external into an internal drainage (n = 4); complications: (a) bleeding (n = 1) followed by 3 d at ICU, discharge after 40 d; (b) septic shock (n = 1) followed by ICU and several laparotomies for programmed lavage and necrosectomy, death after 74 d. Gr. II (n = 13; 48.1%): No complaints (n = 11); external drainage (n = 2); complications/problems out of the 13 cases: 2nd separate pseudocyst (n = 1) with external drainage (since no communication with primary internal drainage); infection of the residual cyst (n = 1) following external drainage; spontaneous PPC perforation (n = 1) following closure of the opening of the cystogastrostomy using clips and subsequently ICU for 2 d. Gr. III (n = 5; 18.5%): No complaints in all patients, in average two endoscopic procedures required (range, 2-6). CONCLUSION: Interventional endoscopic management of pancreatic pseudocysts is a reasonable alternative treatment option with low invasiveness compared to sur- gery and an acceptable outcome with regard to the complication rate (11.1%) and mortality (3.7%), as shown by these initial study results.