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Biomedical subjects

G Schumacher

Publications and source records attributed to G Schumacher.

At least 19 recordsLinked to original sources

Transabdominal ligation of the thoracic duct as treatment of choice for postoperative chylothorax after esophagectomy.

Postoperative chylothorax after injury of the thoracic duct during esophagectomy is a rare but severe complication which may lead to serious problems such as loss of fat and proteins, and immunodeficiency. Without treatment mortality can rise to over 50%. From 1988 to 2005, we treated 10 patients with postoperative chylothorax after 409 resections of the esophagus (2.4%). Of these 10 patients nine underwent transthoracic esophagectomy with gastric pull-up to enable an intrathoracic (n = 7) or cervical (n = 2) anastomosis and one patient received a transhiatal esophagectomy with gastric pull-up and cervical anastomosis. The average amount of postoperative chylus was 2205 mL (200-4500 mL) per day. After a median postoperative interval of 10 days, relaparotomy and transhiatal double ligation of the thoracic duct was performed in nine out of 10 patients. One patient could be managed conservatively. The average amount of chylus was reduced to 151 mL per day (90.5%). Seven patients had no complications, and three suffered from postoperative pneumonia. Two of the patients with pneumonia recovered, and one died. Discharge from hospital, after ligation of the thoracic duct, was possible after a median time of 18 days (11-52). Ligation of the thoracic duct via relaparotomy appeared to be a simple and safe method to treat postoperative chylothorax.

Aged↗

Repeat liver resection for recurrent liver metastases from colorectal cancer.

AIMS: Numerous patients suffer from recurrence after resection of liver metastases from colorectal cancer. Recurrence is frequently restricted to the liver and repeat liver resection may offer a curative option in these patients. This study was conducted to clarify safety and effectiveness of this treatment and to identify prognostic factors of a favourable outcome after repeat hepatectomy. METHODS: Between January 1988 and March 2006 in our institution 811 patients underwent 841 liver resections for metastases from colorectal cancer. Among these, 94 patients underwent a repeat hepatectomy. Patients were identified from a prospective database and retrospectively reviewed. Results of different time periods were assessed and prognostic factors for a favourable outcome were determined. RESULTS: The perioperative morbidity and mortality was 24% (23 of 94) and 3% (3 of 94), respectively. The one-, three-, five- and ten-year survival for all patients in this series was 89%, 55%, 38% and 23%, respectively. In the univariate analysis, pT-stage of the primary, diameter of the largest metastases, surgical radicality, period of resection and distribution of metastases showed statistically significant influence on survival. The multivariate analysis revealed only pT-stage of the primary tumour, surgical radicality and period of resection as independent prognostic factors. CONCLUSIONS: Repeat hepatectomy is a safe and effective treatment for recurrent liver metastases from colorectal cancer. Perioperative risk and long-term survival were similar when compared to the results obtained during the initial resection. Achieving a curative resection is the most relevant prognostic factor for a favourable prognosis after repeat liver resection.

Aged↗

[2-Methoxyestradiol -- a new compound for cancer treatment].

2-Methoxyestradiol (2-ME2), a physiological metabolite of estrogen, inhibits the growth of different tumor types. Many mechanisms of action have been described. In addition to a strong antiangiogenic effect and induction of apoptosis, there are other important mechanisms, such as the inhibition of microtubules during mitosis or the inhibition of the hypoxia-inducible-factor 1alpha (HIF1 alpha). Multidrug-resistant cancer cells appear to be highly sensitive to 2-ME2. Studies with high dosage 2-ME2 have shown that there are only minimal reversible side effects on normal tissue. The experimental data on human tumors have led to the initiation of several clinical trials with promising results. We here summarize the effect of 2-ME2 on various tumor types in vitro and in vivo, as well as the initial results of current clinical trials.

2-Methoxyestradiol↗

Improved long-term graft survival after HO-1 induction in brain-dead donors.

Brain death (BD) of the donor, a risk factor uniquely relevant for organs derived from cadaver donors, influences organ quality by induction of various inflammatory events. Consequently ischemia/reperfusion injury is deteriorated and acute and chronic rejections accelerated. Donor treatment might be an approach to improve the quality of the graft. The induction of heme oxygenase 1 (HO-1) has been shown to exert beneficial effects in living-donor transplantation models. Therefore, we examined the impact of donor treatment with the selective inducer of HO-1, cobalt protoporphyrin (CoPP), on organ quality and transplant outcome in a standardized BD model in a F344-->LEW kidney transplant rat model. Immediately after BD induction, donor animals were administered a single dose of CoPP (5 mg/kg) and in control groups, HO-1 activity was blocked with zinc protoporphyrin (ZnPP, 20 mg/kg). Recipients of organs from brain-dead donors treated with CoPP survived significantly better than those from untreated brain-dead donors (p < 0.05) and intra-graft analysis showed improved histology (p < 0.05). Blockade of HO-1 with ZnPP decreased the survival rates (p < 0.05) comparable to untreated brain-dead donors. Our results demonstrate that HO-1 induction by one single treatment of CoPP in brain-dead donors leads to enhanced allograft survival.

Animals↗

Changes in serum levels of growth factors in healthy individuals after living related liver donation.

INTRODUCTION: To obtain better insight into the kinetics of hepatic growth factors following partial hepatectomy for living related liver donation, we investigated the postoperative changes in serum levels of hepatocyte growth factor (HGF), epidermal growth factor (EGF), vascular epidermal growth factor (VEGF), and transforming growth factor-alpha (TGF-alpha). PATIENTS AND METHODS: Eighteen healthy donors undergoing right hepatectomy for living related donation were enrolled in this study. Serum levels of HGF, EGF, VEGF, and TGF-alpha were measured using enzyme-linked immunosorbent assay kits before surgery, at 2 hours after resection, and daily during 5 days postoperatively. RESULTS: Mean preoperative HGF serum levels in healthy adults were 778 +/- 64 pg/mL. Within 2 hours after operation, they significantly increased to 9608 +/- 3111 pg/mL afterward decreasing to 2726 +/- 241 at day 1 and 2283 +/- 250 pg/mL at day 2. Hereafter HGF serum levels stabilized at increased levels until day 5 (2109 +/- 138, 2047 +/- 219, 2283 +/- 336 pg/mL, respectively). At all time points, the differences between pre- and postoperative HGF levels were significant (P < .01). In contrast, VEGF and EGF serum levels showed no significant differences between pre- and postoperative levels at all time points. TGF-alpha was not detected using a commercially available test with a detection limit of 10 ng/mL, suggesting only low TGF-alpha serum levels following liver resection. CONCLUSION: Significantly increased HGF serum levels after hepatectomy demonstrate its crucial role among the other investigated growth factors in regeneration of the remnant liver tissue during the early period after the operation.

Epidermal Growth Factor↗

Liver transplantation for hepatocellular carcinoma in cirrhosis: prognostic parameters.

Selection of patients suffering from hepatocellular carcinoma (HCC) in cirrhosis for liver transplantation is based upon the number and diameter of tumor nodules but not with vascular invasion. From 1989 to 2003, 1619 liver transplantations were performed in 1471 patients, including 163 patients with an HCC in cirrhosis. Selection criteria were a maximal diameter of up to 5 cm when the tumor appeared to be uninodular, or up to 3 cm in the case of two or three nodules and no vascular invasion prior to transplantation. The postoperative mortality rate was 1.7%. One-, 5- and 10-year survivals were 88%, 62%, and 51%, respectively. Among 1307 transplantations without HCC, the rates were 90%, 84%, and 76%, respectively (P < .0001). Multivariate analysis identified histopathological grading and vascular invasion to predict survival. A subgroup analysis showed 5-year survivals of 67% and 57% for well versus moderately differentiated tumors with vascular invasion. Liver transplantation is a safe and effective long-term treatment for small HCC in cirrhosis. Exeptions from the morphometric rules may be justified for patients with HCC in cirrhosis who show well or moderately differentiated tumors with vascular invasion.

Carcinoma, Hepatocellular↗

[Treatment of iatrogenic bile duct lesions from laparoscopic cholecystectomy].

Injuries of the biliary tract following laparoscopic cholecystectomy have increased with the widespread use of the procedure. Compared to the conventional open choelycstectomy, the incidence of bile duct injuries is at least twofold higher after the laparoscopic procedure. A number of risk factors for the occurrence of bile duct injuries have been well described, including severe inflammation, bleeding, anatomical variations and lack of surgical experience. The appropriate management of bile duct injuries depends on the time of diagnosis after the injury and the type of injury. While peripheral leakages and short strictures can be treated endoscopically, extended injuries and long strictures require surgical reconstruction. The best long-term results are achieved with a tension-free, end-to-side mucosa-to-mucosa Roux-Y hepaticojejunostomy.

Bile Ducts↗

[Adenoviral vector expressing the TRAIL gene driven by the hTERT promoter].

BACKGROUND: Resistance can be overcome by modified adenoviral vectors containing an Arg-Gly-Asp (RGD) sequence. We constructed an adenoviral vector with RGD-modified fibers, expressing the TRAIL gene from the human telomerase reverse transcriptase (hTERT) promoter (designated Ad/TRAIL-F/RGD), and evaluated its antitumor activity in vitro and in vivo. METHODS: The induction of apoptosis by the new vector Ad/TRAIL-F/RGD was evaluated in human carcinoma cells derived from hepatocellular carcinoma (Hep G2, Hep 3b), pancreatic carcinoma (Panc-1, Capan-1), and colon carcinoma (LOVO, SW 620) . Cell viability was measured by the XTT assay and GFP expression and apoptosis induction by fluorescence-activated cell sorting (FACS) and Western blot. In vivo experiments were performed in an orthotopic pancreas tumor model in nu/nu nude mice. RESULTS: Treatment with Ad/TRAIL-F/RGD and Ad/gTRAIL resulted in significantly reduced cell viability in comparison to PBS and Ad/CMV-GFP treatment in all examined human carcinoma cell lines. In addition, mice treated with Ad/TRAIL-F/RGD showed a significantly decreased tumor growth than both control groups. CONCLUSIONS: Our results suggest that Ad/TRAIL-F/RGD may become a potent therapeutic agent for the treatment of different human solid carcinomas.

Adenoviruses, Human↗

Fatal pulmonary scedosporiosis.

We report on a case of scedosporiosis in a 72-year-old German woman. Her disease started with a purulent ulceration of unknown course at her left foot. Soon after onset of oral antibacterial therapy she needed in-hospital treatment because of an acute pneumonia. The infection progressed despite the application of different antibiotics. Microscopic examination of tracheal fluid revealed fungal hyphae and therefore treatment with itraconazole was initiated. However, the patient developed renal failure, required mechanical ventilation and finally died in treatment-resistant septic shock. Post-mortem Scedosporium apiospermum was cultured from lung tissue taken during autopsy. This is the fourth case of human infection caused by Scedosporium species diagnosed in our laboratory during the last 4 years.

Aged↗

Selectin-blocking semisynthetic sulfated polysaccharides as promising anti-inflammatory agents.

Selectin-induced leucocytes rolling along the endothelial surface of blood vessels initiate a complex adhesion cascade, which is an essential step in the cellular immune response. Consequently, blocking the binding between the selectins and their ligands represents a promising strategy for suppressing pathological inflammatory reactions. This study describes the effects of an unfractionated heparin and a low-molecular-weight heparin and a series of structurally well-defined semisynthetic glucan sulfates on selectin-mediated cell-rolling with respect to inhibition. To simulate the blood flow characteristics of postcapillary venules, the rolling experiments were performed in a dynamic-flow-chamber system with immobilized selectins and selectin ligand-carrying U937 cells. The influence of the test compounds on cell rolling was measured by the percentage of adherent cells after a certain flow time and the velocity of the rolling cells. Whereas the test compounds displayed no inhibitory effect on E-selectin-mediated cell rolling, they efficiently blocked the rolling induced by P-selectin. The glucan sulfates were much more active than either unfractionated heparin or low-molecular-weight heparin, or the standard inhibitor Sialyl Lewis(X). Their inhibitory potency turned out to be strongly dependent on various structural parameters, such as sulfation pattern and molecular weight. In conclusion, the semisysnthetic glucan sulfates represent promising candidates in the development of selectin blocking agents.

Animals↗

Bacteria reduction and nutrient removal in small wastewater treatment plants by an algal biofilm.

Attached algae settlement is frequently observed in effluents of wastewater treatment plants at locations with sufficient sunlight. For their growth they incorporate nutrients and the surface of the algal biofilm accumulates suspended solids from the clarified wastewater. During the photosynthesis process of algal biofilms oxygen is produced while dissolved carbon dioxide is consumed. This led to an increasing pH due to the change of the carbon dioxide equilibrium in water. The high pH causes precipitation of dissolved phosphates. Furthermore an extensive removal of faecal bacteria was observed in the presence of algae, which may be caused by the activity of algae. The experimental results indicate the high potential of these attached algae for polishing secondary effluent of wastewater treatment plants. Especially for small wastewater treatment plants a post connected stage for nutrient removal and bacteria reduction can be developed with the aid of an algal biofilm.

Biofilms↗

Improving the effluent of small wastewater treatment plants by bacteria reduction and nutrient removal with an algal biofilm.

In wastewater ponds, bacteria numbers decrease considerably in the case of raised algae concentrations in the effluent. This shows that algae have a high potential for bacteria reduction in wastewater. Simultaneously, algae remove nutrients from the water for the formation of biomass. However, suspended algae also cause a high secondary pollution in the effluent of wastewater treatment plants. By using attached algae, as they are frequently observed as an algal biofilm in the effluent of wastewater treatment plants, the problem of separation of algae and water can be avoided. Furthermore, the algae can be removed simply from the water. In this study the possibilities for bacteria reduction and nutrient removal were examined with the aid of an algal biofilm. The results show that an algal biofilm process can be used for cases where small amounts of wastewater should be treated and a high quality of the effluent should be attained.

Bacteria↗

Case Report. Maxillary sinus infection due to Emericella nidulans.

Fungal infections of the maxillary sinus are frequently caused by Aspergillus species, particularly A. fumigatus. In otherwise healthy persons there is an association with overfilling of dental root canals, when zinc-containing filling materials were used. Below, a maxillary sinus aspergilloma is reported in a young immunocompetent female patient caused by Aspergillus (Emericella) nidulans.

Adult↗

A case of imported paracoccidioidomycosis in a German legionnaire.

We report on a case of the chronic form of paracoccidioidomycosis with swelling and ulcerations of the mouth in a German legionnaire who also suffered from a chronic bronchitis. The patient had worked for many years in Brazil, an area endemic for the disease. Infection due to Paracoccidioides brasiliensis was diagnosed in Germany, more than 10 years after the patient's return. Diagnosis was established by the presence of yeast cells with multipolar budding in the tissue of the oral lesion. Furthermore, the fungus was grown in a liquid Leishmania culture medium. Identification of the fungus was based on morphology and genetic sequencing. Furthermore, IgG antibodies against a 43-kDa antigen of P. brasiliensis were detected in a western blot. After itraconazole therapy (400 mg day(-1)) for 4 weeks, the lesions had disappeared almost completely, but the therapy was continued for further 5 months to avoid relapse of the infection.

Antifungal Agents↗

Polishing of secondary effluent by an algal biofilm process.

The potential in polishing secondary effluent by an algal biofilm composed of different green and bluegreen algae was investigated. During the photosynthesis process of algal biofilm oxygen was produced while dissolved carbon dioxide was consumed. This led to an increasing pH due to the change of the carbon dioxide equilibrium in water. The high pH caused precipitation of dissolved phosphates. The attached algae took up nitrogen and phosphorus during the growth of biomass. In addition to nutrient removal, an extensive removal of faecal bacteria was observed probably caused by adsorption of the algal biofilm and by photooxidation involving dissolved oxygen. The experimental results suggest that a low-cost, close to nature process especially for small wastewater treatment plants for nutrient removal and bacteria reduction can be developed with the aid of an algal biofilm.

Biofilms↗