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Biomedical subjects

F Bittinger

Publications and source records attributed to F Bittinger.

At least 19 recordsLinked to original sources

Endosonography of insulin-secreting and clinically non-functioning neuroendocrine tumors of the pancreas: criteria for benignancy and malignancy.

OBJECTIVE: Endosonography is a powerful tool in the diagnosis of gastroenteropancreatic neuroendocrine tumors. This study was performed in order to characterize endosonographic criteria of malignant and benign neuroendocrine pancreatic tumors focussing on those typically presented to endocrinologists, i.e. insulin-secreting tumors and clinically non-functioning tumors in MEN-1. DESIGN: We studied six benign insulinomas, four hormone inactive benign neuroendocrine adenomas in MEN-1, and three non-metastatic neuroendocrine carcinomas with clinically symptomatic insulin secretion. METHODS: Endosonography was performed using Pentax FG 32 UA endosonoscope with a longitudinal 7.5 MHz sector array. RESULTS: Tumor diameter was larger in malignant tumors (19 - 70 / 47.0 +/- 25.9 mm) than in benign lesions (2.3 - 19 / 9.7 +/- 5.8 mm). Hypoechoic echogeneity was more or less present in benign and in malignant tumors and could not be used as a criteria for differential diagnosis. Heterogeneous or multinodular structure on endosonographic imaging however, was an exclusive feature of malignant tumors. Echo-free areas representing cystic transformation or necrosis and vascular invasion were additional signs of malignancy. CONCLUSIONS: Molecular genetic diagnosis of MEN-1 and new therapeutic developments such as endoscopic surgery make sufficient imaging procedures in the management of neuroendocrine pancreatic tumors mandatory. Besides valid detection and exact localization, endosonography provides criteria for benign and malignant tumors and thus may be helpful in planning therapeutic strategies.

Carcinoma, Neuroendocrine↗

c-erbB-2 expression in small-cell lung cancer is associated with poor prognosis.

Small-cell lung cancer (SCLC) carries a bad prognosis despite good initial response to chemotherapy. It is therefore important to identify molecular markers that influence survival as potential new therapeutic targets. In our study, expression of the tyrosine kinase c-erbB-2 (HER2/neu) receptor in tumor tissues of 107 consecutive newly diagnosed patients with primary SCLC was quantified using a monoclonal antibody directed against the c-terminal domain of c-erbB-2. A clear-cut positive expression of c-erbB-2 was observed in 13% of patients. Surprisingly, c-erbB-2 was an independent prognostic factor (RR = 2.16; p = 0.014) when a proportional-hazard model was adjusted to stage (limited vs. extensive disease) and performance status (WHO I-IV), the most relevant clinical parameters. Similarly, a significant association between c-erbB-2 and survival was obtained if a larger number of clinical parameters were included into the analysis, namely response to chemotherapy, TNM stage, lactate dehydrogenase (LDH), neuron-specific enolase (NSE), gender and age (p = 0.033). Interestingly, c-erbB-2 expression was more relevant for patients with advanced tumors. In the subgroup of patients with bad performance status (WHO II-IV), median survival of patients with undetectable c-erbB-2 expression was 274 days compared with only 23 days for patients with clear-cut positive c-erbB-2 immunohistochemistry (p = 0.0031; log-rank test). Similar results were obtained for patients with extensive disease (p = 0.028) and high TNM stages (T>2 or N>1 or M1; p < 0.068, all comparisons). In contrast, c-erbB-2 expression was not associated with survival in patients with limited disease (p = 0.97), low TNM stages (p > 0.56, all comparisons) and good performance status (p = 0.97). In conclusion, c-erbB-2 is expressed in more than 10% of SCLC. Expression of c-erbB-2 is an independent prognostic factor of survival. The effect of c-erbB-2 expression seems to become more important in advanced stages of the disease. Since c-erbB-2 is a therapeutical target in other types of cancer, further studies to identify the role of c-erbB-2 in SCLC are clearly warranted.

Age Factors↗

Release of non-neuronal acetylcholine from the human placenta: difference to neuronal acetylcholine.

The synthesis and release of non-neuronal acetylcholine, a widely expressed signaling molecule, were investigated in the human placenta. This tissue is free of cholinergic neurons, i.e. a contamination of neuronal acetylcholine can be excluded. The villus showed a choline acetyltransferase (ChAT) activity of 0.65 nmol/mg protein per h and contained 500 nmol acetylcholine/g dry weight. In the absence of cholinesterase inhibitors the release of acetylcholine from isolated villus pieces amounted to 1.3 nmol/g wet weight per 10 min corresponding to a fractional release rate of 0.13% per min. The following substances did not significantly modify the release of acetylcholine: oxotremorine (1 microM), scopolamine (1 microM), (+)-tubocurarine (30 microM), forskolin (30 microM), ouabain (10 microM), 4alpha-phorbol 12,13-didecanoate (1 microM) and tetrodotoxin (1 microM). Removal of extracellular calcium, phorbol 12,13-dibutyrate (1 microM) and colchicine (100 microM) reduced the acetylcholine release between 30% and 50%. High potassium chloride (54 mM and 108 mM) increased the acetylcholine release slightly (by about 30%). A concentration of 10 microM nicotine was ineffective, but 100 microM nicotine enhanced acetylcholine release gradually over a 50-min period without desensitization of the response. The facilitatory effect of nicotine was prevented by 30 microM (+)-tubocurarine. Inhibitors of cholinesterase (physostigmine, neostigmine; 3 microM) facilitated the efflux of acetylcholine about sixfold, and a combination of both (+)-tubocurarine (30 microM) and scopolamine (1 microM) halved the enhancing effect. In conclusion, release mechanisms differ between non-neuronal and neuronal acetylcholine. Facilitatory nicotine receptors are present which are activated by applied nicotine or by blocking cholinesterase. Thus, cholinesterase inhibitors increase assayed acetylcholine by two mechanisms, protection of hydrolysis and stimulation of facilitatory nicotine receptors.

Acetylcholine↗

The biological role of non-neuronal acetylcholine in plants and humans.

Acetylcholine, one of the most exemplary neurotransmitters, has been detected in bacteria, algae, protozoa, tubellariae and primitive plants, suggesting an extremely early appearance in the evolutionary process and a wide expression in non-neuronal cells. In plants (Urtica dioica), acetylcholine is involved in the regulation of water resorption and photosynthesis. In humans, acetylcholine and/or the synthesizing enzyme, choline acetyltransferase, have been demonstrated in epithelial (airways, alimentary tract, urogenital tract, epidermis), mesothelial (pleura, pericardium), endothelial, muscle and immune cells (granulocytes, lymphocytes, macrophages, mast cells). The widespread expression of non-neuronal acetylcholine is accompanied by the ubiquitous expression of cholinesterase and acetylcholine sensitive receptors (nicotinic, muscarinic). Both receptor populations interact with more or less all cellular signalling pathways. Thus, non-neuronal acetylcholine can be involved in the regulation of basic cell functions like gene expression, proliferation, differentiation, cytoskeletal organization, cell-cell contact (tight and gap junctions, desmosomes), locomotion, migration, ciliary activity, electrical activity, secretion and absorption. Non-neuronal acetylcholine also plays a role in the control of unspecific and specific immune functions. Future experiments should be designed to analyze the cellular effects of acetylcholine in greater detail and to illuminate the involvement of the non-neuronal cholinergic system in the pathogenesis of diseases such as acute and chronic inflammation, local and systemic infection, dementia, atherosclerosis, and finally cancer.

Acetylcholine↗

The non-neuronal cholinergic system in the endothelium: evidence and possible pathobiological significance.

An increasing body of knowledge indicates that the cholinergic system is not confined to the nervous system, but is practically ubiquitous. The present paper will address the question of the non-neuronal cholinergic system in vascular endothelial cells (EC). In tissue sections of human skin, immunohistochemical studies using confocal laser scanning microscopy showed ChAT (choline acetyltransferase) activity in the EC of dermal blood vessels. Positive ChAT immunoreactivity was also demonstrated in monolayer cultures of human umbilical vein EC (HUVEC) and a human angiosarcoma EC line (HAEND). That the synthesizing enzyme is not only present in EC, but also active was shown by measuring ChAT activity. Thus, in HUVEC cultures, ChAT activity amounted to 0.78 +/- 0.15 nmol x mg protein(-1) x h(-1) (n = 3), but was only partially (about 50%) inhibited by the ChAT inhibitor bromoacetylcholine (30 microM). In HPLC measurements, a concentration of 22 +/- 2 pmol acetylcholine (ACh) per 10(6) cells was found (n = 6). However, using a cholinesterase-packed analytical column to check the identity of the acetylcholine peak, the peak height was found to be reduced, although a significant peak still remained, indicating the existence of a compound closely related to ACh. Further immunocytochemical experiments indicated that EC in vitro also express the vesicular acetylcholine transporter (VAChT) system. Preliminary immunoelectron microscopic studies suggest a topographical association of VAChT with endothelial endocytotic vesicles. The presented experiments clearly demonstrate the existence of essential elements of the cholinergic system (ChAT, VAChT, ACh) in the human endothelium. The biological functions of ACh synthesized by endothelial cells are the focus of ongoing research activity.

Acetylcholine↗

Microcirculatory dysfunction in sepsis: a pathogenetic basis for therapy?

Sepsis is a frequent complication of multiple organ dysfunction syndrome and remains a major problem of intensive care medicine. It is also a common factor in the final cause of death in hospital populations. Clinical observations, assisted by invasive monitoring techniques as well as pathological-anatomical studies, clearly indicate that microcirculatory dysfunction lies at the centre of sepsis pathogenesis. Numerous animal models, from rodents to primates, many of which employ bacteria or their toxins, especially endotoxins, have helped to shed light on the pathomechanisms leading to this dysregulation in the peripheral circulation. Among these are activation of humoral and cellular inflammatory mediator systems, with special emphasis on neutrophil-endothelial interactions, affecting endothelial barrier function and vasoregulation and ultimately leading to severely perturbed oxygen transport and utilization. In vitro studies have provided more insight into the molecular mechanisms involved in this microcirculatory dysfunction, although much more attention must be directed towards microvascular endothelial cells and the role of heterogeneity of response in various vascular beds. These experimental data must in turn be validated by comparing with the human in situ situation, both clinical and morphological. This review aims at a critical appraisal of the clinical and experimental evidence for sepsis-induced dysregulation of the microcirculation and how knowledge of the underlying cellular and molecular pathology could be used to make therapy more rational and effective. To date, therapeutic approaches, such as anti-cytokine and anti-oxidant regimens, which have been highly successful in experimental models, have failed to demonstrate clinical efficacy. Newer approaches, such as targeting the coagulation system, nitric oxide synthesis or intracellular signal transduction, are also discussed. The necessity to focus on the role of anti-inflammatory mediators, as well as the pathogenetic significance of important molecular groups, such as the heat shock proteins, which until now have been given scant attention, will be stressed.

Animals↗

[Calciphylaxis: ischemic tissue necrosis in chronic renal failure. Case report and review of the literature].

Calciphylaxis is a rare but potentially life-threatening complication in chronic renal failure. It is characterized by ischemic tissue necrosis primarily of the skin. The typical histopathologic finding is microvascular calcification with endovascular fibrosis. Patients typically present with violaceous, mottled and painful lesions which tend to progress to non-healing ulcers and necrosis. Most frequently the lower extremities are involved in a symmetric fashion but the trunk may also be affected. Sepsis from superinfection of the lesions accounts for the high mortality of this disease which is of importance for dermatologists and nephrologists alike. 61-year-old female patient developed lesions of calciphylaxis on both calves two years after beginning hemodialysis to treat renal failure due to diabetic glomerulosclerosis. We discuss aspects of the pathogenesis of calciphylaxis, as well as diagnosis, treatment and means of prevention, and review the current literature.

Biopsy↗

[A case report: suppurative pericardial effusion].

We present the case of a 67 year old woman who was resuscitated due to cardiac tamponade. Examination of the pus fluid showed a bacterial infection with streptococcus milleri. Four days before resuscitation the patient experienced weakness, dyspnoea, increased temperature (39 degrees C), swelling of the neck, and pain on swallowing. Using computed tomography, examination revealed an infection extending from the right tonsil to the mediastinum and into the pericardium. After surgery to remove the retropharyngeal abscess, the patient healed well. Therefore, on presentation of a cardiac tamponade, possible hematogenous or lymphogenous causes or per continuitatem infections should always be considered. In this case the germs in the fluid and the typical patient history indicated an oropharyngeal reason.

Aged↗

Biomaterial-induced sarcoma: A novel model to study preneoplastic change.

In the study of carcinogenesis most interest has focused on carcinomas, as they represent the majority of human cancers. The recognition of the adenoma-carcinoma sequence both in humans and in animal experimental models has given the field of basic oncology the opportunity to elucidate individual mechanisms in the multistep development of carcinoma. The relative scarcity of human sarcomas coupled with the lack of adequate animal models has hampered understanding of the molecular genetic steps involved. We present an experimental model in the rat in which a high incidence of malignant mesenchymal tumors arise around a subcutaneously implanted biomaterial. Nine commercially available biomaterials were implanted in a total of 490 rats of the Fischer strain for 2 years. On average, macroscopic tumors were found in 25.8% of implantation sites over a period from 26 to 110 weeks after implantation. The most frequent tumors were malignant fibrous histiocytomas and pleomorphic sarcomas, although fibrosarcomas, leiomyosarcomas, and angiosarcomas readily developed, the latter especially around polyurethane implants. Of particular interest are the results of a detailed histological study of the capsules around the implanted biomaterials without tumors. Here a spectrum of change from focal proliferative lesions through preneoplastic proliferation to incipient sarcoma could be observed. A parallel immunohistochemical study of peri-implant capsules showed that proliferating cell nuclear antigen was of particular help in identifying these atypical proliferative lesions. To our knowledge this is the first description of a sarcoma model in which preneoplastic lesions can be readily identified and also reproducibly induced. This model provides the molecular biologist with defined stages in the development of mesenchymal malignancy, with which the multistage tumorigenesis hypothesis can be tested, analogous to the well-known adenoma-carcinoma sequence.

Animals↗

Inhibin-alpha CD99, HEA125, PLAP, and chromogranin immunoreactivity in testicular neoplasms and the androgen insensitivity syndrome.

We investigated 115 testicular and 3 epididymal tumors and 6 cases of the complete androgen insensitivity syndrome (AIS) for the expression of inhibin-alpha, CD99, HEA125, PLAP, and chromogranin, using monoclonal antibodies and standard immunhistochemical techniques. Ihibin-alpha was detected in the neoplastic cells in 27 of 27 primary Leydig cell tumors (LCTs), 1 of 1 metastatic LCT, 6 of 20 Sertoli cell tumors (SCTs), 4 of 5 juvenile granulosa cell tumors (GCTs), and 2 of 5 unclassified sex cord-stromal tumors (USCSTs). Except for 2 choriocarcinomas, the choriocarcinomatous component of 1 mixed germ cell tumor, and a small focus of inhibin-positive syncytiotrophoblast in 1 embryonal carcinoma, inhibin-a immunoreactivity was not present in the neoplastic cells of the 38 remaining testicular germ cell tumors; 11 B-cell and 1 T-cell lymphomas; 1 granulocytic sarcoma; and 1 rhabdomyosarcoma of the testis; 1 adenoma of the rete testis, and 3 adenomatoid tumors of the epididymis. Inhibin-alpha immunoreactivity was present in the Sertoli cells and Leydig cells in 5 testicular hamartomas and in 1 Sertoli cell adenoma in 6 cases of AIS; both Sertoli and Leydig cells were also positive in the extranodular testicular parenchyma present in 2 of these cases. CD99 was detected in 10 of 15 primary LCTs, 1 of 7 SCTs, 3 of 5 JGCTs, and in 1 of 5 USCSTs but was not found in any tumor outside the sex cord-stromal category. HEA125 immunostaining was not detected in sex cord-stromal tumors; however, 3 of 12 seminomas, 3 of 12 embryonal carcinomas, 6 of 8 yolk sac tumors, and 1 of 2 teratomas were HEA125 positive. PLAP was not detected in sex cord-stromal tumors except for 4 of 15 primary LCTs but was present in most germ cell tumors. Chromogranin immunostaining was present in the sex cord-like element in 1 of 5 USCSTs, 1 of 8 YSTs, 1 of 2 teratomas, and in 1 of 1 rete adenoma, and in normal adjacent rete testis. In conclusion, although inhibin-alpha and PLAP, and, to a somewhat lesser extent, CD99 and HEA125 immunostaining are helpful in the differential diagnosis of certain testicular neoplasms that are difficult to distinguish on morphologic grounds, chromogranin is far less helpful in this context.

12E7 Antigen↗

Remodeling of peritoneal-like structures by mesothelial cells: its role in peritoneal healing.

BACKGROUND: Intraabdominal adhesions are a common complication following laparotomy. Since the exact mechanisms involved in this processes are unknown we have analyzed in vitro the role of mesothelial cells in peritoneal healing. MATERIAL AND METHODS: Human mesothelial cells from omental tissue were cultivated for 2 weeks in a three-dimensional culture either on or in a collagen type I matrix. The effects of blood and collagen matrix were analyzed by exposing mesothelial cells to an overlying blood clot, simulating intraperitoneal bleeding, or a second collagen layer. The production of collagen types III and IV, fibronectin, and laminin was analyzed with immunohistochemical methods. RESULTS: Mesothelial cells grown on a collagen matrix formed a monolayer of flat or cobblestone-like cells whereas those cultivated in a collagen matrix exhibited spindle-like morphology. Mesothelial cells failed to grow into an overlying collagen matrix, but did grow into a blood clot, emphasizing a potential role of blood clots in peritoneal adhesion formation. Independent of the culture systems mesothelial cells produced collagen type III, fibronectin, and laminin but not collagen type IV. CONCLUSIONS: Our experiments demonstrate remodeling of peritoneal-like structures by mesothelial cells in a three-dimensional culture reflecting their putative role in the reepithelialization after serosal defects, and also in the formation of peritoneal adhesions.

Cells, Cultured↗

Confocal laser scanning microscopy: A nondestructive subsurface histotomography of healthy human bone.

Microscopy of bony tissue usually requires special treatment for decalcification and processing of thin sections. Confocal laser scanning microscopy (CLSM) allows the nondestructive histotomography of organic hard tissue. The aim of this study was to visualize healthy human bone structures and to correlate identical areas in CLSM and conventional light microscopy. Each sample of healthy human lower jaw (n = 20) was divided into three parts: (1) fresh, untreated bony blocks studied by CLSM; (2) MMA-embedded thin sections (without decalcification), HE stained and studied by CLSM and conventional light microscopy (correlation of identical areas); (3) decalcificated, HE stained, histological sections studied by conventional light microscopy. In untreated bony blocks, microstructures such as osteocytes and lamellae were identified by CLSM. These structures could be correlated with conventional light microscopy. In CLSM, subcellular structures cannot yet be interpreted, whereas cytoplastic processes of osteocytes were seen with high contrast. With CLSM, nondestructive histology of cortical bone can be obtained. The risk of artifacts due to pretreatment is minimized, and subsurface visualization does not affect the interpretation.

Histological Techniques↗

Modified cryopreservation and xenotransplantation of human parathyroid tissue.

INTRODUCTION: A modified cryopreservation technique for human parathyroid tissue was compared with the standard method using a programmed freezer. METHODS: Total parathyroidectomy was performed in three groups of 6-week-old Rowett nude rats. Group I (control) underwent no transplantation of parathyroid tissue (n=9). After 10 days, the rats of groups II (n=15) and III (n=15) underwent xenotransplantation of 20 mg cryopreserved human parathyroid tissue, which had been stored in liquid nitrogen at -196 degrees C for 1-22 months prior to xenotransplantation. The parathyroid tissue was derived from 15 parathyroidectomized patients with renal hyperparathyroidism. Two tissue samples were obtained from every patient. One sample from every patient was cryopreserved by means of the technique of programmed cryopreservation: programmed freezing of human parathyroid tissue at a controlled rate of -1 degrees C/min to -80 degrees C prior to transfer to liquid nitrogen (group II). The second sample from every patient was cryopreserved by means of a modified cryopreservation technique: immediate placement of human parathyroid tissue in a freezer at -20 degrees C and transfer to liquid nitrogen after 2 h (group III). Calcium and intact parathyroid hormone concentrations in serum were determined over a period of 60 days. Furthermore, individual differences in the calcium concentrations were assessed for each rat on the basis of the calcium levels recorded preoperatively and at day 60. RESULTS: All animals in the control group developed hypocalcemia. Serum calcium concentrations returned to normal levels 60 days after xenotransplantation of parathyroid tissue, which had been cryopreserved using the modified technique (group III) in 12 of 15 rats (80%). At day 60, serum calcium had normalized in 10 of 15 rats (67%) after xenotransplantation of parathyroid tissue cryopreserved using programmed freezing (group II). After modified cryopreservation (group III), the median individual difference in the calcium concentrations was -0.16 mmol/l after programmed freezing (group II). At the end of the study, a median level of human intact parathyroid hormone of 3.5 pg/ml and 2.4 pg/ml was estimated for groups II and III, respectively. There was no statistical significant difference of the individual differences in the calcium concentrations or of the levels of human intact parathyroid hormone between groups II and III. CONCLUSION: Human parathyroid tissue was successfully xenografted in the present experimental study. The results obtained after cryopreservation using the described modified technique were equivalent to those recorded after controlled freezing in a programmed freezer. The simplified cryopreservation technique therefore appears to be suitable for human parathyroid tissue.

Animals↗

[Significance of eosinophilic granulocytes in relation to allergy and aspirin intolerance in patients with sinusitis polyposa].

BACKGROUND: The development of nasal polyps might be influenced by different factors such as mucosal inflammation. Infiltration with eosinophils is a common finding, although in largely different quantitis. PATIENTS AND METHODS: We investigated 58 patients suffering from nasal polyps who were assigned for endonasal sinus surgery based on endoscopic and CT findings. Out of these patients, 52% have already had sinus surgery and had recurrent polyps. All patients were subjected to both, allergy testing and a functional in vitro test for aspirin intolerance. During surgery, tissue samples were gained and send for histological examination with special respect to eosinophil infiltration. RESULTS: Eosinophil infiltration was observed in 66% of all patients. 37 patients (64%) exhibited aspirin intolerance only, four (7%) had a positive allergy test only, in 9 patients (15%) both, allergy and aspirin intolerance were diagnosed. Allergy and aspirin intolerance were accompanied by eosinophil tissue infiltration. Eosinophil infiltration was more common and more severe if allergy and aspirin intolerance were found together compared with the tissue eosinophilia in patients with either one entity. CONCLUSION: This study confirms the importance of eosinophil infiltration in the pathogenesis of severe or recurrent nasal polyps based on allergy and aspirin intolerance. A coincidance of allergy and aspirin intolerance was found in an unexpected high number of patients.

Adult↗

Induction of stress proteins in human endothelial cells by heavy metal ions and heat shock.

In the present study, we compared the induction of heat shock proteins (HSPs) by heat and heavy metal ions in three different endothelial cell types, namely, human umbilical vein endothelial cells, human pulmonary microvascular endothelial cells, and the cell line EA.hy 926. Our results show that especially Zn(2+) and Cd(2+) are inducers of 70-kDa (HSP70), 60-kDa (HSP60), 32-kDa (HSP32), and 27-kDa (HSP27) HSPs. The strength of inducibility is specific for each HSP. Ni(2+) and Co(2+) only show an inducible effect at very high concentrations, that is, in the clearly cytotoxic range. Furthermore, we investigated the time course of HSP expression and the involvement of heat shock factor-1. Our study demonstrates that the three endothelial cell types that were under investigation show comparable stress protein expression when treated with heavy metal ions or heat shock. The expression of stress proteins may be used as an early marker for the toxic damage of cells. This damage can be an inducer of acute respiratory distress syndrome in which microvascular endothelial lesions occur early. Our study provides evidence that human umbilical vein endothelial cells or EA.hy 926 cells, which are much more easily isolated and/or cultivated than pulmonary microvascular endothelial cells, could be used as alternative cell culture systems for studies on cellular dysfunction in the lung caused by toxic substances, certainly with respect to the expression of HSPs.

Blotting, Western↗

Glucocorticoids mediate reduction of epithelial acetylcholine content in the airways of rats and humans.

The cholinergic system in rat and human airways and the effects of glucocorticoids were investigated by assay of choline acetyltransferase activity, by high-pressure liquid chromatography measurement of acetylcholine, and by anti-choline acetyltransferase immunocyto-/histochemistry. Human bronchi were obtained at surgery from patients with lung cancer. Group 1 patients did not suffer from additional lung diseases and had not been treated with glucocorticoids. Group 2 patients, who suffered in addition to lung cancer from chronic obstructive bronchitis, had been treated for at least 6 weeks before surgery with four puffs of flusinolid daily. Isolated bronchial epithelial cells as well as intact surface epithelium of human bronchi expressed choline acetyltransferase immunoreactivity and choline acetyltransferase enzyme activity (3 +/- 1 nmol/mg protein per h). Ciliated epithelial cells showed strong choline acetyltransferase immunoreactivity at the basal body and the roolet of cilia. Surface epithelium in group 1 and 2 bronchi contained 23 +/- 6 (n = 14) and 1.8 +/- 0.3 pmol/g acetylcholine) (n = 7, P < 0.001), respectively, whereas the transmural acetylcholine content did not differ significantly between both groups. The amount of choline acetyltransferase immunoreactivity appeared similar in the surface epithelium of both groups. In an animal (rat) study the effects of oral dexamethasone (3 mg/day, 1 week) on choline acetyltransferase activity and acetylcholine levels were investigated. Dexamethasone treatment reduced epithelial acetylcholine in the airways and small intestine by about 80% and inhibited epithelial choline acetyltransferase activity. In conclusion, epithelial cells of human airways possess components of the cholinergic system, i.e., contain the synthesizing enzyme choline acetyltransferase and store acetylcholine. The data obtained from the animal study indicate that glucocorticoids can inhibit epithelial acetylcholine.

Acetylcholine↗

Differential expression of cell adhesion molecules in inflamed appendix: correlation with clinical stage.

The diagnosis of 'early inflamed', 'recurrent' or 'sub-acute' appendicitis is often difficult and accompanied by controversies between clinical data, histological findings, and their interpretation. The expression of the intercellular cell adhesion molecule-1 (ICAM-1), the vascular cell adhesion molecule-1 (VCAM-1), and E-selectin has been studied in 61 appendicectomy specimens for possible use as a diagnostic tool. This study demonstrates a different expression of CAM by endothelial (EC) and mesothelial cells (MC) in the various stages of appendicitis, with early E-selectin and ICAM-1 expression in EC, followed by VCAM-1 in EC and MC. Appendices from patients with prolonged clinical symptoms defined by clinicians as 'chronic' appendicitis showed VCAM-1 expression and occasionally weak expression of E-selectin in EC. In several cases, discrepancies were found between the pre-operative 'clinical' diagnosis, the histomorphological findings, and the immunohistological results. In this context, the expression of E-selectin and VCAM-1 in comparison with the histological features has potential significance in the diagnosis of 'early acute', 'sub-acute' or 'recurrent' appendicitis. In addition, a correlation was demonstrated between the histological stages of appendicitis and the kinetics of CAM expression. The study also indicates that the time course of E-selectin expression in vivo is longer than is suggested from in vitro data.

Acute Disease↗