Biomedical subjects

A Encke

Publications and source records attributed to A Encke.

At least 37 records · Page 2Linked to original sources

PubMed1999

Antireflux surgery in children suffering from reflux-associated respiratory diseases.

The aim of our study was to evaluate the success, complications, and morbidity following a modified Thal fundoplication in children with reflux-associated respiratory disease (RARD). We used a procedure consisting of retroesophageal hiatal plasty, wrapping the gastric fundus around the gastroesophageal junction 180 degrees, and fixation of the lesser curvature at the abdominal wall. Follow-up by questionnaire of 128 (77 male, 51 females) out of 196 antireflux procedures between 1992 and 1995 was achieved. Surgical therapy was considered justified whenever there was gastroesophageal reflux resulting in severe recurrent respiratory symptoms. Eleven percent of the children suffered from bronchiectasis. The diagnosis of RARD was based on a high index of suspicion, barium swallow with fluoroscopy, 24-hr two-level pH-monitoring, bronchoscopy, bronchoalveolar lavage and detection of lipid-laden alveolar macrophages, esophago-gastroscopy, and esophageal biopsy. Patients with bronchopulmonary diseases such as allergy, immunodeficiency, cystic fibrosis, primary ciliary dyskinesia, and malformation of the bronchial tree or vessels had been excluded. "Evident improvement" as a result of surgery was reported in 88%, "no change" in 10%, and a "change for the worse" in 2% of patients. Persistent mild difficulties in swallowing were observed in 11%. Paraesophageal hernia, gas-bloat syndrome, and dumping syndrome were not observed. Two children needed a second operation because of relapse. The use of emergency steroidal medication for acute respiratory distress decreased impressively (219 single doses/year before surgery vs. 30 single doses/year after surgery). The need for more than 4 times/year of antibiotic therapy before surgery was reduced from 52. 3% before to 14% after surgery. Most (90.6%) of the parents stated they would agree to have surgery done again if medically indicated. In conclusion, Thal fundoplication is sufficient, safe, and effective in the management of RARD. Complications of the procedure were minor and of little consequence to the patient.

Adolescent↗

PubMed1999

Historical evolution of limb amputation.

The amputation of a limb is one of the oldest surgical procedures. In the course of medical history operative techniques and surgical instruments have been improved continuously. As early as the first century Celsus described an amputation. A major step in the development of the operative technique was the introduction of an artery forceps by Paré during the sixteenth century. Nevertheless, due to a lack of analgesics and narcotics the operation had to take only a few minutes. Therefore the amputation was completed in one cut (i.e., detachment of the skin, muscles, and bone at the same level). This technique, known as "classic circular cut," was modified several times in the following period: to reduce suture tension Petit recommended that we transect the skin first and the muscles and bone more proximally ("two-stage circular cut," 1718), and Bromfield approved that the skin be cut first, the muscles more proximally and the bone most proximal ("three-stage circular cut," 1773). Lowdham (1679), Verduyn (1696), and Langenbeck (1810) changed the operative technique in that they used a soft-tissue flap to cover the bone without tension ("flap amputation").

Amputation, Surgical↗

PubMed1999

Surgical strategies -- anastomosis or stoma, a second look -- when and why?

INTRODUCTION: The indication for performing a primary anastomosis or an intestinal stoma has to be confirmed or negated for every individual case of intestinal ischemia. DISCUSSION: In right-sided colonic emergency, primary anastomosis is possible except when associated with generalized peritonitis. In left-sided colonic ischemia and necrosis, delayed anastomosis is the preferred alternative. In ischemia following surgery for abdominal aortic aneurysms, primary anastomosis is contraindicated. In ischemia of the small bowel, an end-to-end anastomosis should be established whenever possible. CONCLUSION: In the case of intestinal ischemia, a second-look laparotomy is mandatory 24-48 h after initial surgery to ensure bowel viability. This second look should be performed regardless of the patient's postoperative clinical status. Laparoscopy has been successfully used for reexploration in intestinal ischemia, but one has to be aware of the present limitations of experience using this technique.

Anastomosis, Surgical↗

PubMed1999

[Esophageal perforation. A rare complication after operation of degenerative and traumatic pathology of the cervical spine].

Esophageal perforation is a rare complication in the surgical treatment of diseases of the cervical spine. Following cervical discectomy for degenerative arthritis at the C6/C7 level, a 42-year-old male patient experienced a progressive dislocation of a PMMA-implant with impending esophageal perforation. Neurological symptoms including dysphagia worsened and a new fusion had to be performed 3.5 months after initial surgery. On the 2nd postoperative day, a laceration of the esophagus was diagnosed clinically and on esophagogram. After drainage, the perforation healed under antibiotic treatment and enteral nutrition through a percutaneous endoscopic gastrostomy within 5 weeks.

Adult↗

PubMed1998

Development of an ultrasensitive in vitro assay to monitor growth of primary cell cultures with reduced mitotic activity.

Primary cell cultures, such as isolated epithelial cells, neuronal cells, or hepatocytes are characterized by a very low mitotic activity. Monitoring of small changes in cell numbers requires staining with a DNA-specific dye with an extremely high sensitivity and a low inter- and intraassay variability. For this purpose, an ultrasensitive in vitro assay has been developed based on the fluorescent nucleic acid stain PicoGreen. PicoGreen has been shown to detect as little as 0.5 ng pure DNA or 10(2) cells (interassay SD < 10%, intraassay SD < 5%). This is far above the limit of sensitivity of conventional fluorochromes, such as Hoechst 33342 or propidium iodide. To obtain optimum efficacy of PicoGreen, cells were digested with papain for 20 h at 60 degrees C prior to staining. Under these conditions, the slope factor was calculated to be 0.105 relative fluorescence units (RFU)/cell, which is far superior to the slope factor of Hoechst 33342 (0.0137 RFU/cell) or propidium iodide (0.0077 RFU/cell). Analysis of the blank values revealed a very low autofluorescence of PicoGreen, which is only 1/50th of the autofluorescence of Hoechst 33342 and 1/5th of the autofluorescence of propidium iodide. Additional coating of the culture plates with extracellular matrix proteins to prevent cellular dedifferentiation did not influence the high sensitivity of PicoGreen. In conclusion, the PicoGreen-assay seems to be the method of choice when the growth capacity of primary cell cultures needs to be analyzed with high accuracy.

Animals↗

PubMed1998

[Individual prognosis of critically ill patients with septic shock by neural network?].

From 1. 11. 93 to 30. 3. 97, 1149 patients were prospectively studied during their ICU stay. Of them, 114 met the criteria of septic shock, with lethality of 47.3%. A neural network was trained with datasets from 91 of these 114 patients. Testing the trained neural network with the remaining 23 patients, the following result was obtained: all 10 patients dying from septic shock were correctly predicted; of 13 surviving patients, 12 were correctly identified (sensitivity 100%; specificity 92.3%).

APACHE↗

PubMed1998

[Inflammatory esophageal stenosis with intramural pseudodiverticulosis of the esophagus].

Esophageal intramural pseudodiverticulosis is a very rare disease with unknown etiology, which especially affects male patients between 45 and 65 years. This disease is characterized by dilatation of the esophageal submucosal glands and their outlets. Stenosis caused by esophagitis due to intramural pseudodiverticulosis is found in most of the known patients. All patients presented with dysphagia, usually of long duration. The characteristic radiographic appearance is numerous intramural esophageal contrast-filled diverticulosis-like pouches--4 mm in depth.

Diagnosis, Differential↗

PubMed1998

Maintained function of primary human hepatocytes by cellular interactions in coculture: implications for liver support systems.

The application of primary hepatocytes in hybrid artificial liver systems has been hampered by the gradual loss of differentiated morphology and function in vitro. Therefore, we have established a coculture model of autologous human hepatocytes and biliary epithelial cells (BEC) in collagen gel in the presence of hepatotrophic growth factors. Furthermore, we examined the effect of hepatocyte cell perfusion in a women multicompartment capillary membrane system. Normal hepatocytes isolated from human liver produced albumin for more than 2 weeks in serum-free media, and were further stimulated by conditioned medium. When cocultured with BEC, albumin secretion was greatly enhanced, suggesting that cellular interactions promote tissue-specific differentiation. When perfused in bioreactors, albumin levels were maintained at steady state for longer than 2 weeks. These data indicate that differentiation of primary hum hepatocytes can be maintained by coculture interactions and three-dimensional hybrid organ devices, providing appropriate growth factors and matrix for tissue regeneration.

Cell Communication↗

PubMed1998

Historical development of surgical instruments exemplified by hemostatic forceps.

We describe the historical development of surgical instruments exemplified by hemostatic forceps, starting with antique and medieval forceps used for the arrest of bleeding to modern atraumatic hemostatic forceps used for vascular reconstruction. Their development proceeded mainly in three steps: (1) development of ligature forceps directly for hemostasis (Celsus, first century AD; Paré, 1582; L. Heister, 1743; (2) development of atraumatic forceps, which facilitate vascular reconstruction or anastomosis creation by temporarily clamping vessels (Höpfner, 1903; Stich, 1907; Jeger, 1913; (3) construction of tangential forceps, which, by partially clamping vessels with partial maintenance of blood flow, allow the reconstruction or anastomosis of large vessels in a side-to-side technique. The first tangential occlusion clamp was developed by Friedrich Trendelenburg (1844-1924) in 1908, when he established the operative treatment for embolism of the pulmonary artery. This clamp was later modified by A. W. Meyer (1927) and V.P. Satinsky (ca. 1950).

Hemostasis, Surgical↗

PubMed1998

Role of HLA antigens in liver transplantation with special reference to cellular immune reactions.

In previous statistical analyses we have demonstrated the importance of the dualistic effect of HLA on liver transplant survival: HLA compatibility decreases cellular rejection but also increases other immunologically mediated, HLA-restricted mechanisms of allograft injury. More recently these results have been confirmed by other researchers, and several studies have shown higher recurrence rates of infectious diseases such as hepatitis B and C and CMV hepatitis for HLA-compatible liver transplants. Although current practice does not consider HLA in liver transplantation, cellular in vitro studies show a significant role of HLA antigens in clinically relevant phenomena. While increasing the amount of infection-related immune damage, HLA compatibility also decreases the alloproliferative response of the recipient to the donor tissue. Further studies must examine whether non-HLA antigens such as tissue-specific antigens and heat-shock-proteins participate in this process, and how target cells can present different peptides such as soluble HLA antigens or viral proteins to the recipient.

Cells, Cultured↗

PubMed1998

A randomized, double-blind trial for stress ulcer prophylaxis shows no evidence of increased pneumonia.

BACKGROUND: H2-receptor antagonists are commonly used for stress ulcer prophylaxis on intensive care units. However, there is evidence that via the route of an elevated gastric pH, followed by bacterial overgrowth and subsequent tracheal aspiration, pneumonia could occur. In line with this assumption total gastrectomized patients should develop a very high incidence of pneumonia, which is actually not the case. We therefore formulated the hypothesis that stress ulcer prophylaxis with H2-receptor antagonists does not lead to an increased pneumonia rate. METHODS: A total of 158 patients with mechanical ventilation > or =48 hours of a surgical intensive care unit were randomized to the following groups: A, placebo (n = 57); B, pirenzepine (3 x 10 mg intravenously, n = 44); and C, ranitidine (3 x 50 mg intravenously, n = 57). RESULTS: The pneumonia rate in ranitidine-, pirenzepine-, and placebo-treated patients is 10 of 57, 10 of 44, and 12 of 57, respectively. CONCLUSIONS: Pneumonia rate is not adversely affected by H2-receptor antagonists in stress ulcer prophylaxis.

Adolescent↗

PubMed1998

Dedifferentiation of human hepatocytes by extracellular matrix proteins in vitro: quantitative and qualitative investigation of cytokeratin 7, 8, 18, 19 and vimentin filaments.

BACKGROUND/AIMS: Liver cirrhosis and carcinogenesis are accompanied by an alteration in extracellular matrix material. Histological studies reveal upregulation of the intermediate filaments cytokeratins 8 and 18 and de novo synthesis of vimentin, and cytokeratin 7 or 19 in hepatocytes. The aim of this study was to investigate how these two processes are linked. METHODS: Human hepatocytes were seeded: (i) on the matrix components collagen I, IV, laminin, or fibronectin; (ii) on stoichiometrically different complete matrices, derived from human placenta (matrix I) or the Englebreth-Holm-Swarm tumor (matrix II), and (iii) inside a three-dimensional collagen I sandwich. Filament expression and assembly were measured by cytofluor analysis or confocal laserscan microscopy. RESULTS: The matrix components or complete matrices triggered enhancement of cytokeratins 8 and 18 and de novo synthesis of cytokeratins 7, 19 and vimentin in a characteristic way. Confocal images demonstrated a dense and uniform network of cytokeratin 18 in freshly isolated cells, which was "replaced" by a few, thick protein bundles within 20 days. Interestingly, newly synthesized cytokeratin 19 structurally resembled the cytokeratin 19 organization in biliary epithelial cells. Marked cytokeratin alterations could be partially prevented when hepatocytes were grown in a three-dimensional collagen sandwich. CONCLUSIONS: Pathological alterations to the chemical composition, molecular structure, or spatial arrangement of the liver matrix lead to specific changes in the intermediate filament pattern in human hepatocytes. We assume that degradation of the matrix results in pathological alterations to the hepatocyte-receptor matrix-ligand ratio, followed by a switch from physiological to pathological cell-activation.

Cell Count↗

PubMed1998

Isolated hypoxic perfusion with mitomycin C in patients with advanced pancreatic cancer.

AIMS: Chemotherapy as a palliative therapy option for patients with advanced pancreatic cancer remains disappointing. Some authors have recently claimed high response rates and a prolongation of median survival after regional chemotherapy. Isolated perfusion may result in the highest drug concentrations within the target tissue without causing systemic side-effects. An established, commercially available system of isolated hypoxic perfusion (IHP) was therefore evaluated in patients with unresectable or recurrent pancreatic cancer. PATIENTS AND METHODS: IHP was performed in 17 patients with unresectable pancreatic cancer. Five women and 12 men with a median age of 61 years were treated. A 20-min isolated hypoxic perfusion was performed after 40 mg of mitomycin C (MMC) had been instilled into the running perfusion system over 5 min. Tumour response was evaluated by CT-scan 6 weeks after IHP. RESULTS: Twenty perfusions were carried out in 17 patients. Within 10 min of perfusion, the perfusate's PO2 decreased to 13% of the baseline value. Five minutes after the infusion of MMC a local concentration of 15.2 mg/litre was observed. Toxicity-related deaths did not occur. Nausea and vomiting (NCI> or =II: 12 episodes) were the most frequently observed toxicities after IHP. In five patients (29%) a deep vein thrombosis occurred. None of the treated patients responded to the regimen used in this trial. The median survival time after IHP was 4.2 months (range 1.3-21). CONCLUSIONS: The overall rate of side-effects and complications after IHP was high. In spite of some hopeful reports on this treatment in recent years, IHP did not show any benefit in terms of tumour response or median survival. On the basis of these experiences, this procedure should no longer be used as treatment for patients with unresectable or recurrent pancreatic cancer.

Aged↗

PubMed1998

Inhibition of endothelial receptor expression and of T-cell ligand activity by mycophenolate mofetil.

The novel immunosuppressive drug mycophenolate mofetil (CellCept, MMF) blocks DNA-synthesis by the inhibition of the enzyme inosine monophosphate dehydrogenase (IMDH). IMDH is also involved in the synthesis of adhesion receptors which are known to play an important role in the regulation of cell-cell contacts. Therefore, application of MMF might lead to a reduction of cellular infiltrates in the course of transplant rejection. To evaluate the therapeutic value of MMF, we investigated to what extent MMF blocks T-lymphocyte infiltration in vitro with regard to (a) adhesion to endothelial cells, (b) horizontal migration along these cells and (c) penetration through the endothelial cells. The results demonstrated a strong inhibition of both CD4+ and CD8+ T-cell adhesion and penetration by MMF. The ID50 value for CD4+ T-cell adhesion was calculated to be 0.03 microM and the ID50 value for CD4+ T-cell penetration 1.21 microM. MMF did not significantly influence the horizontal migration of T-lymphocytes along the human vascular endothelial cell (HUVEC) borders. FACS-analysis revealed a diminished E-selectin and P-selectin expression on endothelial cell membranes in the presence of MMF. Although MMF did not interfere with the synthesis of T-cell adhesion ligands, the binding activity of lymphocytic leucocyte function associated antigen 1 (LFA-1), very late antigen 4 (VLA-4) and PSGL-1 (P-selectin glycoprotein ligand 1) to immobilized intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and P-selectin was impaired. Moreover, MMF prevented VLA-4 and PSGL-1 receptor accumulation on the membranes of T-cell pseudopodia. It can be concluded that MMF possesses potent infiltration blocking properties. MMF evoked down-regulation of specific endothelial membrane molecules and the loss of protein localization in the lymphocyte protrusions might be predominantly responsible for the observed blockade of cell adhesion and penetration.

CD4-Positive T-Lymphocytes↗

PubMed1998

Novel mode of action of the calcium antagonist mibefradil (Ro 40-5967): potent immunosuppression by inhibition of T-cell infiltration through allogeneic endothelium.

Cyclosporin A reduces the mitotic activity of allosensitized lymphocytes, but fails to limit emigration of these cells into the donor organ. However, the modulation of both lymphocyte proliferation and infiltration are desirable characteristics of immunosuppressive therapy. The calcium-channel blocker, verapamil, has recently been shown to effectively prevent the transmigration of CD4+ and CD8+ T cells through allogeneic endothelium. Mibefradil (Ro 40-5967) represents a new generation of calcium antagonists with high potency and long-term activity. To evaluate the immunosuppressive potential of this drug, the influence of mibefradil on lymphocyte adhesion to, horizontal locomotion along, and penetration through allogeneic endothelium (HUVEC) was performed. When lymphocytes were prestimulated for 24 hr with mibefradil, adhesion and penetration were dose-dependently reduced. The adhesion ID50 values were 3.4 microM (CD4+ T cells) versus 9.2 microM (CD8+ T cells) and 2.1 microM (CD4+ T cells) versus 3.9 microM (CD8+ T cells) with regard to penetration. Mibefradil also effectively blocked horizontal locomotion. Specific down-regulation of T-cell binding to the P-selection receptor (ID50: CD4+ T cells, 0.8 microM: CD8+ T cells, 1.2 microM) and to the intracellular adhesion molecule-1 (ICAM-1) receptor (ID50: CD4+ T cells, 1.9 microM; CD8+ T cells, 1.5 microM) by mibefradil seems to be responsible for the decreased adhesion and penetration rates. Reduction of intracellular F-actin in T lymphocytes could diminish cell locomotion. In conclusion, the potent suppressive properties of mibefradil support its use as a co-medication in cyclosporin A-based immunosuppressive therapy.

Actins↗

PubMed1998

Evidence of survival benefit of extended (D2) lymphadenectomy in western patients with gastric cancer based on a new concept: a prospective long-term follow-up study.

BACKGROUND: The use of extended (D2) lymph node dissection in gastric cancer achieves better locoregional tumor control than limited (D1) lymphadenectomy, but its influence on survival is controversial. The value of D2 resection is unproven in randomized trials. However, a survival benefit in favor of D2 resection has been shown in reports from some specialized centers. This study was undertaken to assess whether D2 resection improves survival. We evaluated the efficacy of D2 resection on the basis of a new concept that eliminates the stage migration phenomenon. METHODS: D2 resection achieved with a standardized technique in this prospective study included dissection of the perigastric lymph nodes (stations 1 through 6, D1 resection), as well as those at the celiac axis (stations 7 through 11) and at hepatoduodenal ligament (station 12, N2 level). We evaluated survival data of patients with involved nodes at stations 7 through 12 (N2 disease) because these nodes are left behind in a D1 resection. RESULTS: D2 resection resulted in a resection of cure in 31 patients with N2 disease, a 25% (31 of 125) increase of the curative resection compared with a supposed D1 resection. The 5-year survival rate for N2 patients was 17%, which demonstrates the therapeutic benefit of the D2 resection. In patients with pN0 and pN1 disease, the 5-year survival rates were 71% and 53%, respectively. Overall hospital mortality and morbidity were 1.3% (2 of 146) and 33.4% (40 of 146), respectively. CONCLUSIONS: D2 resection can be performed safely and is of therapeutic value in patients with advanced lymph node metastases. Furthermore, the survival data suggest indirectly a possible beneficial effect for patients with node-negative disease (N0) or early node metastases (N1).

Adult↗

PubMed1998

Randomized trial of surgery versus surgery followed by adjuvant hepatic arterial infusion with 5-fluorouracil and folinic acid for liver metastases of colorectal cancer. German Cooperative on Liver Metastases (Arbeitsgruppe Lebermetastasen)

OBJECTIVE: To determine the impact of adjuvant hepatic arterial infusion (HAI) on survival relative to resection alone in patients with radical resection of colorectal liver metastases. SUMMARY BACKGROUND DATA: Nearly 40% to 50% of all patients with colorectal carcinoma develop liver metastases. Curative resection results in a 5-year survival rate of 25% to 30%. Intrahepatic recurrence occurs after a median of 9 to 12 months in up to 60% of patients. The authors hypothesized that adjuvant intraarterial infusion of 5-fluorouracil (5-FU) might decrease the rate of intrahepatic recurrence and improve survival in patients with radical resection of colorectal liver metastases. METHODS: Between April 5, 1991, and December 31, 1996, patients with colorectal liver metastases from 26 hospitals were stratified by the number of metastases and the site of the primary tumor and randomized to resection of the liver metastases followed by adjuvant HAI of 5-FU (1000 mg/m2 per day for 5 days as a continuous 24-hour infusion) plus folinic acid (200 mg/m2 per day for 5 days as a short infusion), or liver resection only. RESULTS: The first planned intention-to-treat interim analysis after inclusion of 226 patients and 91 events (deaths) showed a median survival of 34.5 months for patients with adjuvant therapy versus 40.8 months for control patients. The median time to progression was 14.2 months for the chemotherapy group versus 13.7 months for the control group. Grade 3 and 4 toxicities (World Health Organization), mainly stomatitis (57.6%) and nausea (55.4%), occurred in 25.6% of cycles and 62.9% of patients. CONCLUSION: According to this planned interim analysis, adjuvant HAI, when used in this dose and schedule in patients with resection of colorectal liver metastases, reduced the risk of death at best by 15%, but at worst the risk of death was doubled. Thus, the chance of detecting an expected 50% improvement in survival by the use of HAI was only 5%. Patient accrual was therefore terminated.

Adult↗

PubMed1998

[CO2 pneumoperitoneum inhibits in vitro proliferation of human carcinoma cells].

Up to this day, the influence of laparoscopy and hyperbaric carbon dioxide on the growth of tumor cells is not yet clear. Cells of human colonic carcinoma CX-2 and pancreatic carcinoma DAN-G were exposed to carbon dioxide under pressures of zero, 6 and 12 mmHg. Proliferation was measured by counting in NEUBAUER's counting chamber and by DNAstaining with Pico Green over five days after exposition. In a third experiment, dead cells were stained with Propidium Iodide and detected by flow cytometry. Only DAN-G after 6 mmHg showed at day five an increasing proliferation rate. Furthermore, exposition to carbon dioxide lead to an increased necrosis of cells. All other groups showed a significantly decreased proliferating activity of the cells exposed to carbon dioxide in comparison to a control group.

Air Pressure↗