Biomedical subjects

A Morgenroth

Publications and source records attributed to A Morgenroth.

15 recordsLinked to original sources

PubMed2005

Inhibition of malignant glioma cell growth by a survivin mutant retrovirus.

Glioblastoma multiforme (GBM) is a highly malignant brain tumor that is resistant to conventional radiotherapy and chemotherapy. The median survival time of patients with GBM has remained less than 2 years despite concerted efforts to improve therapy. As a new approach to treat GBM we generated retroviral particles encoding mutant survivin for transduction of glioma cells. We demonstrate here that retroviral overexpression of a nonphosphorylatable Thr-34 --> Ala mutant of survivin (survivinT34A), in the glioma cell lines U373 and H4 resulted in a marked increase in the percentage of cells bearing multiple nuclei, which was accompanied by significantly decreased cell proliferation, and in greater numbers of cells with hypodiploid DNA content. Administration of the broad caspase inhibitor z-Val-Ala-Asp(OMe)-fluoromethyl-ketone did not reduce the cell death rate. Yet increased nuclear translocation of apoptosis-inducing factor (AIF) was observed in cells transduced with survivinT34A, indicating caspase-independent cell death. Transduction of retroviral vectors encoding wild-type survivin also led to the appearance of multinuclear cells. In contrast to mutant survivin, overexpressed wild-type survivin did not increase the cell death rate and no enhanced nuclear AIF translocation was observed. We suggest that retroviral vectors delivering mutant survivinT34A might be employed for the treatment of glioblastoma.

Apoptosis↗

PubMed2002

Efficient transduction and long-term retroviral expression of the melanoma-associated tumor antigen tyrosinase in CD34(+) cord blood-derived dendritic cells.

Differentiation of genetically modified CD34(+) hematopoietic stem cells into dendritic cells (DCs) will contribute to the development of immunotherapeutic anticancer protocols. Retroviral vectors that have been used for the transduction of CD34(+) cells face the problem of gene silencing when integrated into the genome of repopulating stem cells. We reasoned that a high copy number of retroviral DNA sequences might overcome silencing of transgene expression during expansion and differentiation of progenitor cells into functional DCs. To prove this, we utilized a retroviral vector with bicistronic expression of the melanoma-associated antigen tyrosinase and the enhanced green fluorescent protein (EGFP). Human cord blood CD34(+) cells were transduced with vesicular stomatitis virus G-protein (VSV-G) pseudotyped Moloney murine leukemia virus (MoMuLV) particles using 100-150 multiplicity of infection. During expansion of transduced cells with immature phenotype, transgene expression was strongly silenced, but upon differentiation into mature DCs, residual transgene expression was retained. Intracellular processing of the provirally expressed tyrosinase was tested in a chromium release assay utilizing a cytotoxic T cell clone specific for a HLA-A*0201-restricted tyrosinase peptide. We suggest that retroviral transduction of tumor-associated antigens in hematopoietic progenitor cells and subsequent differentiation into DCs is a suitable basis for the development of potent anti-tumor vaccines.

Antigens, CD34↗

PubMed1997

Two-center German experience with aortic endografting.

PURPOSE: To report the results of a two-center study of endovascular abdominal aortic aneurysm (AAA) exclusion using a polyester-covered nitinol stent-graft. METHODS: Candidates were evaluated with arteriography and computed tomography. Criteria for endovascular therapy were a proximal aortic neck > 10 mm in length and < 25 mm in diameter, no bilateral internal iliac artery involvement in the aneurysm, no markedly tortuous common iliac arteries (CIAs) or CIAs < 7 mm in diameter, and no superior mesenteric artery occlusive disease. Patients were treated with the Mialhe Stentor and Vanguard stent-grafts in either tube or bifurcated versions. RESULTS: Between August 1994 and November 1996, 149 patients (mean age 67 years, range 49 to 90) were admitted to the study. Overall primary technical success (aneurysm exclusion without endoleak) was 87% (130 patients): 78% (7 patients) for tube grafts and 88% (123 patients) for bifurcated endografts. The rate of local, remote, or systemic complications was 10.8%, with a 30-day mortality rate of 0.7%. During an average 13.5-month follow-up, there were no late deaths. Four of 20 endoleaks sealed spontaneously, 14 were treated with endoluminal techniques, and 2 remain untreated by patient request. Three graft limb thromboses occurred; one was treated surgically, one with lytic therapy, and one was untreated. Secondary patency was 96%. CONCLUSIONS: Endoluminal repair of infrarenal AAAs using straight or bifurcated grafts is a feasible alternative to conventional surgical repair. Longer follow-up and more experience with refined endograft models will elucidate the durability of this endovascular approach to treating AAAs.

Aged↗

PubMed1995

Tuberous sclerosis complex with end-stage renal failure.

Renal angiomyolipoma is common in the tuberous sclerosis complex (TSC), the classic features of which are facial angiofibroma, seizures, and mental retardation. We report a family with three affected members demonstrating the wide spectrum of TSC-associated lesions ranging from asymptomatic findings to life-threatening complications. The predominant symptoms of the index patient were hypertension and mild renal insufficiency at age 48, resulting in end-stage renal failure at age 63 due to giant bilateral angiomyolipoma of the kidneys. The two TSC-affected siblings had died years previously, one from pulmonary lymphangioleiomyomatosis and the other during an epileptic state; the latter had situs inversus totalis as another remarkable finding. The diagnosis of TSC may be overlooked if CNS symptoms are absent and if cutaneous lesions are masked by cosmetic procedures, as occurred in the index case. Chronic renal failure due to angiomyolipoma is not widely known to clinical nephrologists, but develops in approximately 15% of TSC patients. Displacement of functional renal parenchyma by abnormal tissue appears to be the major pathogenetic mechanism leading to end-stage renal failure. Angiomyolipomas can be diagnosed from this characteristic sonographic pattern and the demonstration of fatty tissue in CT or MRI. Multiple renal cysts are also common in TSC. Therefore TSC should be considered in the differential diagnosis of polycystic kidney disease.

Angiomyolipoma↗

PubMed1991

Pleural penetration of ciprofloxacin in patients with empyema thoracis.

We evaluated the pharmacokinetics of a single 200-mg dose of ciprofloxacin, administered as a 30-minute infusion, into pleural exudate in five elderly patients with empyema thoracis. Ciprofloxacin was measured by HPLC and the pharmacokinetic parameters were determined by noncompartmental methods. Mean peak serum levels 30 minutes after administration were 1.98 +/- 0.07 mg/L. Terminal serum half-lives ranged from 3.9 to 5.1 h. Mean concentrations of ciprofloxacin in pleural exudate were 1.44 +/- 0.42 mg/L at a mean time of 4.5 +/- 2.5 h. After this time, the pleural exudate level exceeded the corresponding serum twofold to tenfold. The mean percentage penetration into the inflammatory compartment was approximately 210 percent. Our data suggested that ciprofloxacin penetrates well into the pleural fluid of patients with empyema thoracis. The concentrations achieved were well above the MIC90 of most pathogens normally found in patients with empyema thoracis for a period of approximately 12 h.

Aged↗

PubMed1989

[Enoxacin--comparative pharmacokinetics and tissue penetration].

The choice of an antimicrobial agent is primarily dependent on its antimicrobial activity and the pharmacokinetics in the host. The gyrase inhibitors differ in their antimicrobial spectrum as well as in their pharmacokinetics. In this review we compare key pharmacokinetic parameters of the most important 4-quinolones. Clearly, there are differences in their absorption, their sensitivity of the absorption process to food or di-or trivalent cations. On a weight basis enoxacin tends to have higher plasma levels then e.g. ciprofloxacin or norfloxacin and also tissue penetration of enoxacin as determined in the Body Fluid Model is superior to ciprofloxacin or norfloxacin. The elimination of enoxacin is mostly by the kidney (approximately 50-60% of dose) another 12-15% are metabolized in the liver. Renal failure therefore requires dose adjustments. The inhibitory effect of enoxacin on other compounds' metabolism has to be considered.

Anti-Infective Agents↗

PubMed1989

Six years' experience with perthoracic core needle biopsy in pulmonary lesions.

Six years' experience of percutaneous core needle biopsy using the Hausser needle in 502 patients, aged 20-89 years, is reported. A biopsy was carried out when sputum and bronchoscopic methods had failed to establish a definitive histological diagnosis. Over 60% of the lesions were peripheral and about 40% were 2-4 cm in diameter. A correct diagnosis was made by this means in 312 of the 339 patients shown eventually to have a malignant lesion (92%) and in 130 of 146 patients with a benign lesion (89%). A definitive diagnosis was never established in 17 patients. Complications arose in 15% of cases. Pneumothorax occurred in 43 patients (7%), of whom 12 required a chest drain. Further complications included a small haemoptysis (less than 30 ml) in 27 patients (5%), haemothorax necessitating a chest drain in three patients, and an intrapulmonary haematoma in five patients. There were no fatal or permanent complications. Percutaneous core needle biopsy is a valuable procedure with a high diagnostic accuracy in these patients and a low rate of complications.

Adult↗

PubMed1989

Primary chondrosarcoma of the left inferior lobar bronchus.

A primary chondrosarcoma arising in the left inferior lobar bronchus is described in a 67-year-old man. The symptoms upon admittance were dyspena, cough with purulent sputum and weight loss. The tumor was removed by pneumonectomy. Eight months later the patient died of massive mediastinal lymph node involvement. While tracheobronchially located primary pulmonary chondrosarcoma tends to remain localized, the peripheral variety tends toward mediastinal lymph node involvement and thoracic metastasis. The treatment of choice is resection in a radical manner, whenever possible.

Aged↗

PubMed1988