Severe exacerbations and mortality in COPD patients: A retrospective analysis of the database of the Hungarian National Health Insurance Fund.

INTRODUCTION: COPD is one of the most common pulmonary diseases and one of the leading causes of death worldwide. Exacerbations of COPD include acute worsening that could lead to hospitalization and death. In this study, our objective was to investigate the natural course of moderate and severe exacerbations (SAE) and mortality in the Hungarian population in the past decade. METHODS: A retrospective financial database analysis was performed to examine the risk of additional SAEs and death after the first ever SAE in COPD patients, using the financial database of the Hungarian National Health Insurance Fund (NHIF). Patients were enrolled between 2009.01.01. and 2019.12.31. if they had received at least one inhaled drug (LABA, LAMA, ICS or SABA/SAMA) and had been hospitalized for a COPD exacerbation (ICD-10 code J44). RESULTS: A total of 63,037 patients with COPD were enrolled after their first SAE. Of them, 27,095 patients suffered at least one subsequent SAE, and 32,120 patients died during the 10-year follow-up. The median survival was 4.7 years. The risk of subsequent hospitalizations increased significantly after each SAE, with hazard ratios ranging from 1.65 to 5.01. The risk for mortality was increased after each SAE, but did not increase further with the number of SAEs. Moreover, the risk for subsequent SAE and death increased with moderate exacerbations; however, this risk did not increase further with each event. CONCLUSIONS: Despite a relevant improvement in COPD treatment, the natural course of exacerbations remained unchanged. This result highlights the importance of preventing exacerbations and the need for more research to better predict them.

Prevalence and screening of active tuberculosis in a prison in the South of Brazil.

SETTING: Tuberculosis (TB) remains a challenge in Brazil, particularly among prison inmates. OBJECTIVE: To assess TB prevalence by active case finding in a public prison in southern Brazil. DESIGN: Prison inmates were screened for TB using the presence of cough and chest X-ray (CXR) from October 2014 to August 2016. Presence of cough, irrespective of duration, and abnormal CXRs were further investigated using laboratory tests. RESULTS: Of 10 326 inmates screened, 196 had confirmed TB (1898/100 000 inmates screened). At the first screening, 1759 inmates presented with cough only, 16 of whom had TB; among those with only abnormal CXR (n = 1273), 92 had TB. Xpert was positive in 155 patients, and negative in 15; these results were confirmed using culture. The remaining 26 patients did not undergo Xpert testing and were confirmed using microscopy (27%), culture (42%) or both (31%). CONCLUSION: The combined use of symptom screening (cough) and CXR was much more effective in maximising TB yield than using either method alone. If patients presenting with cough alone had not been investigated, 10% of TB patients would have been missed; if those with abnormal CXR but no cough had not been investigated, 51% of TB patients would have been missed. We detected high TB prevalence in this prison by using active case finding.

Medication prescribing and monitoring errors in primary care: a report from the Practice Partner Research Network.

INTRODUCTION: Medication errors have been associated with poor patient outcomes and pose significant public health consequences. Establishing medication safety quality indicators is crucial to capturing the pervasiveness of preventable errors and is a fundamental first step in the process of improvement. In this article, a study is presented in which a set of medication prescribing and monitoring quality indicators were developed, and adherence to them was assessed among a group of US primary care practices. METHODS: Twenty Practice Partner Research Network practices in 14 US states with 94 clinicians and 52,246 active adult patients participated in the study. All practices use a common electronic medical record with dosing, interaction and monitoring decision support features. A consensus development process was used to select indicators in the categories of inappropriate treatment, dosing, drug-drug and drug-disease interactions, and monitoring of potential adverse events. Data extracted electronically from practices' electronic medical record were used to assess practice-level adherence with the indicator set as of 1 July 2008. RESULTS: Thirty medication safety indicators were selected. Across all practices, inappropriate treatment, dosing, drug-drug and drug-disease interactions were avoided in 75%, 84%, 98% and 86% of eligible patients, respectively; monitoring of preventable adverse drug events occurred in 75% of patients. There was wide variability in practice adherence with the indicators. DISCUSSION: The consensus development process was successful in selecting a broad set of primary care medication safety quality indicators. Although aggregate adherence was relatively high in this group of practices, opportunities exist to improve potential errors in treatment selection, dosing and monitoring.

Application of main component fraction collection method for purification of compound libraries.

In order to support high-throughput library purification, a novel UV triggered fraction collection method was developed in which a maximum-seeking-algorithm-driven, six-port valve collects the largest chromatographic peak. This straightforward strategy achieves the one sample-one fraction approach, thus resulting in a simpler and less error prone workup procedure. The effectiveness of this main component fraction collection method will be illustrated here by the results of the purification of compound libraries (altogether 6086 compounds, having an averaged success rate of 79.4%). Advanced applications, where the desired component differs from the main component, will also be discussed.

Vascular changes play a role in the pathogenesis of necrotizing enterocolitis in asphyxiated newborn pigs.

Necrotizing enterocolitis (NEC) is the most common acquired gastrointestinal emergency in neonates. We have developed an animal model of NEC in asphyxiated newborn pigs and investigated the effects of asphyxia on blood flow in superior mesenteric artery and abdominal aorta, cardiovascular data, arterial acid-base and blood gas parameters, and endothelial cytoskeletal structure in mesenteric microvasculature. Anesthetized, mechanically ventilated newborn pigs were included in two groups: piglets underwent severe asphyxia, and sham-operated control animals. A cardiovascular and metabolic failure developed in asphyxiated piglets approximately 1 h after the induction: severe hypotension and bradyarrhythmia were seen and significant reductions of the blood flow were measured in the superior mesenteric artery and abdominal aorta during the critical phase. Rearrangement of cytoskeletal actin structure corresponding to enhanced vascular permeability was seen with bodipy phallacidin in mesenterial endothelium of asphyxiated piglets after a 24-h recovery period. In conclusion, severe vasomotor changes during asphyxia may result in mesenteric endothelial dysfunction implicated in increased vascular permeability, edema formation, and development of NEC in asphyxiated piglets.

Successful surgical management of a prenatally diagnosed intrapericardial teratoma.

Congenital intrapericardial teratoma is a rare, usually benign tumour frequently associated with massive pericardial effusion, cardiac compression, and severe cardiorespiratory distress shortly after birth. Surgical removal is not only curative but also potentially lifesaving because these lesions often become fatal if not promptly excised. We present a case of a newborn with a huge intrapericardial teratoma diagnosed in utero. After normal delivery the infant underwent surgical removal and has had clinical follow-up for more than 11 months.

Effect of subsoiling on the yield of sugar beet under conditions of rhizomania infection.

The rhizomania is known in Hungary since 1982. The causal agent, Beet necrotic yellow vein benyvirus (BNYVV) is transmitted by a soil-borne fungus Polymyxa betae Keskin. A field experiment was done under rhizomania infested and non-infested conditions to compare the yield parameters of five tolerant and four sensitive sugar beet hybrids. Tolerant varieties produced higher root yield under rhizomania infected conditions. The root yields of the sensitive varieties were similar to the tolerant ones on the uninfested field, but the root mass of some tolerant varieties exceeded the production of the former group. Subsoiling was carried out in two strips of a heavily infested field, while conventional soil cultivation was done on the other parts. There was not any other difference in the cultivation of the treated and control areas. Sugar beet root samples were collected at the time of harvesting from the subsoiled and control plots. Beet necrotic yellow vein virus (BNYVV) infection was tested by means of ELISA. Virus content, yield and yield parameters of samples were compared. There were no significant differences in virus infection between sugar beet roots derived from subsoiled and untreated plots. Ratio of BNYVV infected plants was about 90% in both areas. However, yield and yield parameters showed remarkable difference. Root yield of treated plots, calculated from average individual root weight and 80,000 plant/ha plant density exceeded by 140% the yield of control. Sugar content was 2.6% higher and the harmful non-sugar content was lower on the subsoiled plots. Owing to the favourable chemical and technological value of beet the white sugar content was approximately three-times higher on the treated area.

Sn-zeolite beta as a heterogeneous chemoselective catalyst for Baeyer-Villiger oxidations.

The Baeyer-Villiger oxidation, first reported more than 100 years ago, has evolved into a versatile reaction widely used to convert ketones-readily available building blocks in organic chemistry-into more complex and valuable esters and lactones. Catalytic versions of the Baeyer-Villiger oxidation are particularly attractive for practical applications, because catalytic transformations simplify processing conditions while minimizing reactant use as well as waste production. Further benefits are expected from replacing peracids, the traditionally used oxidant, by cheaper and less polluting hydrogen peroxide. Dissolved platinum complexes and solid acids, such as zeolites or sulphonated resins, efficiently activate ketone oxidation by hydrogen peroxide. But these catalysts lack sufficient selectivity for the desired product if the starting material contains functional groups other than the ketone group; they perform especially poorly in the presence of carbon-carbon double bonds. Here we show that upon incorporation of 1.6 weight per cent tin into its framework, zeolite beta acts as an efficient and stable heterogeneous catalyst for the Baeyer-Villiger oxidation of saturated as well as unsaturated ketones by hydrogen peroxide, with the desired lactones forming more than 98% of the reaction products. We ascribe this high selectivity to direct activation of the ketone group, whereas other catalysts first activate hydrogen peroxide, which can then interact with the ketone group as well as other functional groups.

Demonstration of neuronal networks in the human upper urinary tract using confocal laser scanning microscopy.

PURPOSE: To our knowledge innervation of the upper urinary tract and its role in motility and sensation are not clearly understood. The whole mount preparation technique provides 3-dimensional (D) morphology of the innervation and its relationship of branching and interconnecting nerve fibers to each other and to the neighboring tissues. Confocal laser scanning microscopy provides dramatic optical advantages for detecting 3-D structures in thick specimens. We investigated the distribution and morphology of the neuronal structures in the human upper urinary tract using the whole mount preparation technique and confocal laser scanning microscopy. MATERIALS AND METHODS: Whole mount preparations of the human renal pelvis and ureter were stained by standard immunohistochemical method using various neuronal markers (protein gene product 9.5, neuron specific enolase and neurofilament). The 3-D architecture of the specimens was investigated with the help of confocal laser scanning microscopy. RESULTS: We detected 2 mesh-like neuronal networks or plexus in the human upper urinary tract. The first and more prominent plexus was located in the submucosa between the lamina propria and tunica muscularis, and the second neuronal network was found between the smooth muscle fibers of the ureteral wall. There were frequent interconnections between the 2 networks in the ureteral wall. CONCLUSIONS: To our knowledge our study shows for the first time that there are 2 well formed mesh-like neuronal plexus in the human upper urinary tract. Our findings suggest that the autonomic nervous system of the human upper urinary tract may have a significant role in the propagation, coordination and modulation of ureteropelvic peristalsis.

[Problems of differential diagnosis in synovial sarcoma]. / Differenciáldiagnosztikai problémát okozó synovialis sarcoma.

The authors present a woman's case (age 50), who was hospitalised several times as she often had pain in her left leg and knee for one year. The pain increased in the last 2 months. The final diagnosis, the primer synovial sarcoma of the left knee was justified only post mortem. Not only this alteration in the knee caused the pain in the left leg. The symptoms of sciatic pain caused by lumbal discus herniation also occurred which made the diagnosis more difficult. Referring to relevant data in literature the authors analyse the differential diagnostic aspects of the final diagnosis and the clinical spectrum of the illness.

Three-dimensional morphology of c-Kit-positive cellular network and nitrergic innervation in the human gut.

CONTEXT: -c-Kit-positive interstitial cells of Cajal (ICC) appear to play a key role in the normal motility function and development of intestine. Nitric oxide is considered to be the most important messenger of inhibitory nonadrenergic, noncholinergic nerves in the enteric nervous system. OBJECTIVES: The aims of this study were to examine the distribution of nitrergic innervation and ICCs in normal human bowel and to demonstrate interconnections between ICCs and nitrergic nerves and smooth muscle fibers using histochemical and immunohistochemical double-staining methods with a whole-mount preparation technique and confocal laser scanning microscopy. METHODS: Full-thickness small and large bowel specimens were obtained at autopsy from 18 children who died of nongastrointestinal diseases. A whole-mount preparation was performed for all specimens, and double staining was carried out with nicotinamide adenine dinucleotide phosphate (reduced form, NADPH)-diaphorase and c-Kit immunohistochemistry. Double immunofluorohistochemistry with neuronal nitric oxide synthase and c-Kit using confocal laser scanning microscopy was also performed in all specimens. RESULTS: The whole-mount preparation facilitated 3-dimensional visualization of the meshlike network of NADPH-diaphorase-positive nerve fibers in the myenteric plexus surrounded by a reticular network of c-Kit-positive ICCs. The dense c-Kit-positive cellular network located between longitudinal and circular muscle layers and at the innermost part of circular muscle layer intermingled with the myenteric plexus. Short, fine processes of ICCs made connections with the muscle fibers and c-Kit-positive cells. CONCLUSIONS: The development of double-NADPH-diaphorase histochemistry and c-Kit immunohistochemistry staining technique in a whole-mount preparation provides an easy and useful method for investigating the association between c-Kit-positive cellular network and nitrergic neuronal network in the human bowel wall. The characteristic profiles of the c-Kit-positive cellular network and nitrergic neuronal network and their relationship with the smooth muscle fibers provide a morphologic basis for investigating intestinal motility disorders.

Evidence of an inflammatory pathologic condition in "normal" appendices following emergency appendectomy.

BACKGROUND: Appendices removed from patients with suspected appendicitis often appear normal on histologic examination. OBJECTIVE: To study appendix specimens for the expression of inflammatory markers as an indicator of presence of an inflammatory response in this subgroup of patients. METHODS: Cyclooxygenase 1 and 2, prostaglandin E(2), inducible nitric oxide synthase, and major histocompatibility complex class II were investigated by immunofluorohistochemistry using confocal laser microscopy in 15 acutely inflamed appendix specimens, 39 histologically classified "normal" appendices, and 11 negative control specimens. RESULTS: Strong expressions of all the inflammatory mediators were found in the mucosa of inflamed appendices, in approximately 50% of histologically normal appendices from patients with a clinical diagnosis of appendicitis, and in none of the normal control specimens. CONCLUSION: This study confirms the existence of a subgroup of appendicitis within the so-called histologically normal appendices in which evidence of an inflammatory pathologic condition is only obvious at a molecular level. The initiating signal for this and all other forms of clinical appendicitis still remains elusive.

Three-dimensional morphology of gut innervation in total intestinal aganglionosis using whole-mount preparation.

BACKGROUND: Total intestinal aganglionosis (TIA) is a rare form of Hirschsprung's disease (HD). The aim of this study was to examine the 3-dimensional morphology of the myentric plexus of the entire gastrointestinal tract in a newborn with total intestinal aganglionosis. METHODS: Whole-mount preparations were made of the entire gastrointestinal tract using NADPH-diaphorase histochemistry and c-kit (a marker of interstitial cells of Cajal) immunohistochemistry. RESULTS: Whole-mount preparations of the esophagus, stomach, and duodenum showed 3-dimensional morphology of the myenteric plexus forming a meshlike network of nerve fibers, connected to each other and to ganglia. There were large numbers of NADPH-diaphrase-positive nerve fibers between the muscle fibers in the circular muscle layer. In esophagus, stomach, and duodenum, c-kit-positive interstitial cells of Cajal (ICC) formed a 3-dimensional network between the two muscle layers and also were abundant within the circular muscle layer. In the jejunum, ileum, and colon, the myenteric plexus was absent and was replaced by hypertrophic nerve bundles that stained weakly with NADPH-diaphrase. Circular muscle layer completely lacked NADPH-diaphrase-positive nerve fibers. The c-kit-positive ICCs in the jejunum, ileum, and colon were sparse and localized mainly around the nerve trunks between the circular and longitudinal muscle layers. CONCLUSIONS: Whole-mount preparation is an elegant 3-dimensional technique in which the relationship of branching and interconnecting nerve fibers to each other and to muscle can be seen clearly. Absence of myenteric plexus, lack of nitrergic innervation, and depletion of interstitial cells of Cajal in the bowel wall throughout the small and large bowel contribute to the inability of the smooth muscle to relax, thereby causing lack of peristalsis in TIA.

Sn-MCM-41--a heterogeneous selective catalyst for the Baeyer-Villiger oxidation with hydrogen peroxide.

A new heterogeneous catalyst, Sn-MCM-41, is described for the Baeyer-Villiger reaction with hydrogen peroxide which selectively activates the carbonyl function for the nucleophilic attack by the oxidant, with high chemoselectivities when double bonds are present in the molecule.

A method for detection of doxorubicin-induced cardiotoxicity: Flow-mediated vasodilation of the brachial artery.

BACKGROUND: The cardiotoxicity of anthracyclin antibiotics such as doxorubicin (DOX) is a serious side effect in cancer therapy. Reduced antioxidant capacity may be a factor responsible for DOX-induced oxidative damage to the heart. The endothelial dysfunction that results from excessive free radicals can be easily detected by flow-mediated vasodilation (FMD) of the brachial artery. OBJECTIVES: To determine the change in endothelial function after intravenous DOX bolus; to determine the change in biochemical parameters, reflecting increased activity of free radicals or decreased endogenous antioxidant capacity, after intravenous DOX bolus; and to determine the relation between alteration of en-dothelial function after the first DOX bolus and the change in left ventricular function during follow-up. PATIENTS AND METHODS: Twenty-two patients, with either non-Hodgkin's lymphoma (18 patients) or Hodgkin's disease (four patients) were enrolled for the study (seven women and 15 men), with a mean age of 37.3+/-13.7 years. Each patient was treated with a DOX-containing regimen. The actual mean dose of DOX was 33+/-12 mg/m(2). FMD was evaluated before and after DOX administration. In nine patients more frequent measures were taken to determine the time course of change in FMD after DOX administration. FMD was measured 6, 12, 24 and 48 h after DOX. On average each patient was followed up for 18.6+/-8.1 months following the first DOX administration. The mean cumulative DOX dose was 229+/-112 mg/m(2) by the end of the follow-up period. Left ventricular ejection fraction was determined regularly during and at the end of the study. RESULTS: FMD was normal (more than 5%) at baseline in each patient but decreased significantly after DOX bolus (9.9+/-4.4% versus 6.1+/-4.6%, P<0.02). Marked individual differences were found in FMD changes after DOX. Patients who had a more than 5% decrease in FMD after DOX bolus were pretreated with 1000 mg of vitamin C intravenously, just before the next intravenous bolus of DOX was given. The decrease in FMD was prevented. Stepwise multiple regression analysis showed that the decrease in left ventricular ejection fraction during follow-up significantly and independently correlated with the cumulative DOX dose and the value of FMD alteration after the first DOX bolus administration. CONCLUSIONS: FMD in the brachial artery was significantly impaired after the first DOX bolus. The marked individual differences suggest different antioxidant capacities in these patients. The results suggest that alterations in FMD after DOX allows for detection of patients with insufficient antioxidant capacity and patients at a higher risk of DOX-induced cardiotoxicity.

Role of occupational asbestos exposure in Hungarian lung cancer patients.

OBJECTIVE: What is the frequency of occupational asbestos exposure among patients suffering from malignant respiratory tumours and how many of these tumours are associated with asbestos in Hungary? METHODS: An internationally established questionnaire with 29 questions, covering the most characteristic activities of asbestos exposure at the workplace was completed for 300 patients with respiratory malignancies, i.e. 297 patients with lung cancer and three with mesothelioma of the pleura. From the questionnaire, the smoking habits were estimated and cumulative asbestos exposure was assessed in fibre-years. Additionally, lung X-rays were classified and the national data on the incidence of malignant pleura mesothelioma were analysed. RESULTS: A cumulative asbestos exposure of 25 fibre-years or more was detected in 11 patients with lung cancer (4%) and in each of the three patients with pleural mesothelioma (100%). In a further 72 patients (24%), cumulative occupational asbestos exposure was assessed as below 25 fibre-years (between 0.01 and 23.9 fibre-years). In this group, car and truck mechanics, and installation and construction workers using asbestos-cement were registered. Among patients with an asbestos exposure of 25 fibre-years or more, six asbestos-cement production workers were observed, among them the three mesothelioma cases. A weak but significant association between positive X-ray findings and exposure estimates could be demonstrated. Additionally, results of the lung tissue fibre counts by scanning transmission electron microscopy were available for 25 of the lung cancer patients. A good correlation was observed between the asbestos fibre counts and the assessment of cumulative asbestos exposure. In Hungary, 84 cases of pleural mesothelioma were registered in 1997 and 73 in 1998. These numbers correspond to an annual incidence of about one new case per 100,000 inhabitants older than 15 years. CONCLUSIONS: The annual incidence of lung cancer in Hungary is about 6,000. Since in our series of lung cancer patients about 4% were observed, which could be accepted as representing occupational disease because of a cumulative exposure to 25 fibre-years or more, the annual asbestos related lung tumour incidences may be estimated to be approximately 150 or more. The proportion of nearly two estimated cases of lung cancer per case of pleural mesothelioma corresponds to international experience. Up to now, lung cancer cases only exceptionally have been registered as occupational diseases, i.e. they were seriously under-diagnosed in Hungary. For improving this situation, diagnostic assistance by a self-interview with a questionnaire covering the working history for all newly diagnosed lung cancer patients would be helpful.

Neuronal hypertrophy in acute appendicitis.

OBJECTIVE: The pathogenesis of appendicitis remains poorly understood. However, there is increasing evidence of involvement of the enteric nervous system in immune regulation and in inflammatory responses. This study was set up to characterize the status of the enteric nervous system in normal and in inflamed appendixes. METHODS: S100- and 2',2'-cyclic nucleotide 3' phosphodiesterase-positive Schwann cells, synaptophysin, and neuron-specific, enolase-positive nerve fibers and tryptase-positive mast cells were evaluated with immunohistochemical staining in surgically resected appendixes from 20 children with histologically proven acute appendicitis (HA), 10 histologically normal appendixes (HN) from patients with a clinical diagnosis of appendicitis, and 10 normal appendixes from patients undergoing elective abdominal surgery. Immunostained sections were subjected to quantitative image analysis. The number and size of ganglia and the number of nerve fibers, Schwann cells, and mast cells in each tissue compartment was quantitatively or semiquantitatively measured. RESULTS: Increased numbers of fibers, Schwann cells, and enlarged ganglia, widely distributed in the muscularis externa and submucosa, were seen in all HA appendixes and in 4 of 10 HN appendixes. The number and size of ganglia in muscularis externa and in the submucosa of appendixes with HA were significantly greater compared with those in control appendixes (P <.001). A significantly increased number of individually stained nerve fibers and Schwann cells (P <.05) were present in the muscularis externa in HA appendixes compared with control appendixes. Significantly increased numbers of tryptase-positive mast cells (P <.05) were present in the submucosa, muscularis, and especially in the lamina propria in HA specimens, compared with that of control tissue. CONCLUSIONS: The significant increase in neural components and mast cells in acute appendicitis is unlikely to develop during a single acute inflammatory episode. This suggests an underlying chronic abnormality as a secondary reaction to repeated bouts of inflammation, obstruction, or both. These results challenge our current understanding of the pathophysiological processes that give rise to acute appendicitis.

The innervation of human bowel mucosa and its alterations in Hirschsprung's disease using a whole-mount preparation technique.

The innervation of the human bowel wall and its structural and functional changes in Hirschsprung's disease (HD) are well-recognised. The luminal surface of the bowel acts as a multifunctional barrier, and modifications in its physiochemical properties can result in serious complications such as enterocolitis (EC). The whole-mount preparation (WMP) technique produces a three-dimensional (3D) picture to better demonstrate the neuronal networks and the relationship of branching and interconnecting nerve fibres to each other. The aim of this study was to investigate the innervation of the mucosal layer in normal and HD bowel using a WMP immunohistochemistry technique in order to better understand the pathophysiology of HD. Full-thickness bowel specimens were collected from 9 HD patients at pull-through operation. Normal control small- and large-bowel specimens were collected from 10 patients at the time of bladder augmentation. Suction rectal biopsies from 8 patients with chronic constipation and 2 patients with HD were also included in this study. A WMP of the mucosal layer was made and stained with various neuronal markers (S100, PGP 9.5, and LICAM) using fluorescein immunohistochemistry. PGP 9.5, S100, and L1CAM immunofluorescence staining of the normal mucosa demonstrated a characteristic 3D meshlike neuronal network of uniform thickness surrounding the crypts. In the aganglionic bowel S100, PGP 9.5, and L1CAM-positive meshlike networks were replaced by thick nerve trunks in the muscosa without any interconnecting network. The present study demonstrates for the first time the 3D morphology of mucosal innervation in normal and aganglionic bowel. The WMP technique clearly demonstrated that the mucosal innervation in HD is morphologically abnormal, and this may adversely influence secretory and absorptive functions of the bowel. WMPs using suction rectal biopsy specimens may be a useful additional technique to diagnose HD.

Immunolocalization of the gap junction protein Connexin43 in the interstitial cells of Cajal in the normal and Hirschsprung's disease bowel.

BACKGROUND: Interstitial cells of Cajal (ICC) are pacemaker cells between gastrointestinal smooth muscles; they generate spontaneous slow waves of the smooth muscle layers and mediate neurotransmission. The cellular network of ICC is connected by Gap junctions to each other and to the smooth muscle cells. Although there have been several studies reporting distribution of ICC in the normal bowel and pathological conditions such as Hirschsprung's disease, there is little information on the crucial role of Gap junctions in the intercellular communication in the gut musculature. The aim of this study was to investigate the immunolocalization of the Gap junction protein Connexin43 in the normal and Hirschsprung's disease (HD) bowel using whole-mount preparation technique and confocal laser scanning microscopy. METHODS: Full-thickness bowel specimens were collected at pull-through operation from 8 patients diagnosed as having HD. Normal control large bowel specimens were collected from 12 patients during bladder augmentation operation. Whole-mount preparation was performed on all specimens and double immunostaining was carried out using anti c-kit and antiConnexin43 antibodies. The immunolocalization was detected with the help of confocal laser scanning microscopy. RESULTS: Connexin43 immunoreactivity appeared in and between the c-kit-positive cells and along the smooth muscle fibers of the normal bowel and ganglionic part of HD bowel. In the aganglionic part of HD bowel there was no expression of Connexin43. In the transitional zone of HD the Connexin43 staining was weak and colocalized only in the processes of the c-kit-positive Cajal cells. CONCLUSIONS: Results of this study show for the first time that Gap junctional protein Connexin43 is present in the ICCs, which form a 3-dimensional network in the normal bowel wall. The lack of expression of Connexin43 in the aganglionic bowel and reduced expression in the transitional zone of HD suggest that the impaired intercellular communication between ICCs and smooth muscle cells may partly be responsible for the motility dysfunction in HD.