Biomedical subjects

K Engelmann

Publications and source records attributed to K Engelmann.

At least 19 recordsLinked to original sources

PubMed2004

[Intraocular epithelial downgrowth - report on 14 cases from 1986 to 2000].

BACKGROUND: Diffuse and cystic epithelial downgrowth occur rarely, but they represent a mostly preventable potential cause of blindness as sequels to trauma and surgery. The aim of this study is to report on the etiology and course of disease in patients with histologically verified epithelial downgrowth. PATIENTS AND METHODS: From 1986 until 2000 the ophthalmopathological laboratory of the University Eye Hospital Hamburg-Eppendorf received 13 (4 external) referrals. Ten patients with cystic of diffuse intraocular epithelial downgrowth were treated and 9 eyes were operated on in the Hospital. RESULTS: At presentation 4/10 patients had a visual acuity of < or = 0.1, and 2/10 had no light perception. A cystic epithelial downgrowth was verified histologically in 9/13, and a diffuse form in 4/13 patients. Mucin production was proven histochemically in 1/9 intraocular epithelial downgrowth sections. In one case a spontaneous iris cyst was detected by the immunohistological examinations. Trauma (10/14) and surgery (3/14) were the most frequent causes and were symptomatic on average 17 years after the primary event. A curative surgery was done in 13/14 patients (5 x en bloc excision, 2 x penetrating keratoplasty, 1 x iridectomy, 2 x enucleations, 3 x external) resulting in no recurrences during the follow-up of 4(1/2) years (1 - 12 years). The postoperative visual acuity was ameliorated in 5/9, worsened in 2 patients, and 2 were enucleated. CONCLUSIONS: Epithelial downgrowth is a rare but preventable cause of blindness. The most important prophylaxis is meticulous primary surgery including a sufficient wound closure. The visual outcome depends on the preoperative conditions.

Adolescent↗

PubMed2003

Phase II study of the efficacy and safety of cisplatin-epinephrine injectable gel administered to patients with unresectable hepatocellular carcinoma.

PURPOSE: To study the efficacy and safety of percutaneous cisplatin-epinephrine (CDDP-EPI) injectable gel in patients with localized unresectable hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Eligible patients had histologically proven HCC, no prior treatment except for surgery, and no more than three tumors (each measured < or = 7 cm, total tumor volume < or = 200 cm(3)). They were treated percutaneously under ultrasound or computed tomography (CT) guidance, with up to 10 mL of CDDP-EPI gel (1 mL contains 4 mg of CDDP and 0.1 mg of EPI) per treatment and four treatments in 6 weeks to a maximum of eight treatments. The primary end points were tumor response, defined by change of percentage of tumor necrosis according to CT criteria, and safety. Survival parameters were secondary end points. RESULTS: From June 1997 to April 2000, 58 patients (median age, 65 years) entered the study. All patients were assessable for safety, and 51 were assessable for efficacy. The median number of treatments was four (range, one to eight treatments). Objective response rate was 53% (27 of 51 patients), including 16 complete and 11 partial responses. Of the 27 responders, 14 (52%) subsequently developed progressive disease, but in most of them (93%), a new tumor arose at untreated liver sites. Median survival was 27 months (range, 18.4 to 35.7 months). The 1-, 2-, and 3-year survival rates were 79%, 56%, and 14% respectively. The procedure was well tolerated with only minor side effects. CONCLUSION: Percutaneous local ablation with CDDP-EPI injectable gel can induce significant tumor necrosis and local control for localized unresectable HCC, and the treatment is well tolerated.

Adult↗

PubMed2003

[Pathogenesis of choroidal neovascularization. Old concepts, new questions].

Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world but the pathogenesis remains poorly understood. Malfunction of the retinal pigment epithelium (RPE) plays a central role in the disease and leads to either choriodal atrophy or proliferation. This article reviews the current concepts of the development of choriodal atrophy and neovascularisation. Furthermore, available animal models and potential therapeutical targets are discussed.

Age Factors↗

PubMed2003

[Interstitial photodynamic laser therapy for liver metastases: first results of a clinical phase I-study].

PURPOSE: Development and evaluation of a new photodynamic treatment technique for the laser therapy of liver malignancies MATERIAL AND METHODS: The combination with new catheter systems enables the use of the photodynamic therapy (PDT) to treat also tumors in parenchymal organs. So far it is mainly used to treat superficial or endoluminal tumors. The presented study is part of a multicenter phase I-study. We treated 5 patients with colorectal liver metastases with the new photosensitizer SQN 400 and following interstitial photodynamic laser treatment. Evaluation of tumors were performed by contrast-enhanced CT scans. RESULTS: In the contrast enhanced CT scans the development of a complete necrosis within a radius of 1 cm around every single fibre could be shown. Additional the ablation of tumors with the combined use of several fibres is possible. Severe complications or toxicities were not observed. CONCLUSION: The photodynamic laser therapy of liver malignancies is a minimal invasive procedure with little side effects which produces sharply defined yet small volumes of necrosis.

Aged↗

PubMed2003

[MR-guided biopsies of undetermined liver lesions: technique and results].

PURPOSE: To evaluate safety and precision of liver tumor biopsies performed in an open low field system using different sequence techniques. MATERIALS AND METHODS: In 47 patients with liver tumors, MR-guided biopsies were performed in a low field system (0.2 Tesla, Magnetom Open, Siemens) using two different sequences. The procedure was monitored with T1-weighted FLASH sequences (TR/TE = 100/9; 70(3)) in all patients and with FISP-Rotated-Keyhole-sequence (TR/TE = 18/8; 90(3)) in additional 20 patients. After positioning of the needle tip in the tumors, 166 biopsy specimens were acquired with 16 G cutting needles (Somatex*). The diameter of the biopsied lesions ranged from 1 to 10 cm (mean diameter 3.2 cm). Visibility of the needles and precision of the biopsies were evaluated. RESULTS: All interventional biopsies were performed without vascular or organ injuries. Adequate specimens for histologic interpretation were obtained in 42 cases (89.3%). The biopsy results were non-specific in 2 patients (4.2%) and the lesions missed in 3 patients (6.3%). Mean in-room time was 35 minutes and the intervention time was 8.3 minutes. T1-weighted FLASH images proved optimal for confirming needle-tip placement during the biopsies or punctures. Organs, tumors and vessels were easily identified. The FISP sequence proved to be inferior in visualizing vessels and tumors. CONCLUSION: MR-guided liver biopsies are safely and precisely performed using T1-weighted FLASH-sequences with sufficient visualization of the lesions and might be complementary to US- or CT-guided biopsies.

Adult↗

PubMed2002

CT-guided intratumoural administration of cisplatin/epinephrine gel for treatment of malignant liver tumours.

To analyze prospectively the interventional and clinical aspects of computed tomography-guided direct intratumoural injection of a novel chemotherapeutic administration and the parenchymal changes of tumour and necrosis in malignant liver tumours. Eight patients with 17 colorectal liver metastases were treated with a mean of 5.1 injections and nine patients with 13 hepatocellular carcinoma nodules with a mean of 3.1 treatments with computed tomography guided local applications of a novel cisplatin/epinephrine gel. This application provides a higher local and lower systemic drug concentration. Volumes of tumour and necrosis prior and after treatment were measured by computer generated volumetric analysis. Contrast enhanced studies verified pretherapeutic viable tumour volumes with a value of 77.4 ml in the metastases and 29.2 ml in the hepatocellular carcinoma nodules. Intratumoural drug application resulted in a significant increase of necrosis and a decrease in viable tumour volume to be 68.3 ml in metastases and 14.5 ml in hepatocellular carcinoma. Local therapy control rate for the follow up to 6 months was 38 and 71% for the group of metastases and hepatocellular carcinoma, respectively. Direct intratumoural injection of cisplatin/epinephrine injectable gel is a feasible and good tolerated method and results in the development of a statistically significant increase in necrosis in malignant liver tumours. For hepatocellular carcinoma a higher local therapy control rate compared to colorectal metastases can be reported.

Adult↗

PubMed2002

[Rheophoresis. A systematic approach to therapy of age-related macular degeneration (AMD)?].

BACKGROUND: Choroidal microcirculation is impaired in age-related macular degeneration (AMD), and leads to deposition of lipids and proteins in Bruch's membrane. Rheophoresis can improve choroidal microcirculation by eliminating high molecular weight, rheologically relevant plasma proteins. The objective of this post-certification study was to analyse the effect of rheophoresis in 10 AMD patients. PATIENTS AND METHODS: A total of 6 patients with early AMD and 4 with late AMD in one eye (initial visual acuity equivalent 0.2-0.8) received rheophoresis treatment 10 times over an 18-week period. Visual acuity and color vision were determined initially and after 3, 5 and 12 months and fluorescein angiography was performed. RESULTS: Patients with early AMD showed improvement of visual acuity (2 lines on ETDRS charts) in 2 out of 6 cases and a stable visual acuity in 4 out of 6 cases 1 year after rheophoresis, whereas patients with late AMD showed improvement of visual acuity (2 lines on ETDRS charts) in 1 out of 4 cases and a stable visual acuity in 3 out of 4 cases. In red-free fundus photography, a reduction in drusen size and number could be observed in 4 out of 10 cases. CONCLUSION: The results of this investigation seem to be in accordance with data from previously published controlled clinical trials. Recommendations for the indication of rheopheresis for AMD should be further defined and evaluated within the framework base of a multicentric cooperative study.

Aged↗

PubMed2001

Identification and topology of variant sequences within individual repeat domains of the human epithelial tumor mucin MUC1.

This study shows for the first time that the tandemly repeated icosapeptide of human MUC1 underlies a genetic sequence polymorphism at three positions (underlined): PDTRPAPGSTAPPAHGVTSA. The concerted replacement DT-->ES (sequence variation 1) and the single replacements P-->Q (sequence variation 2), P-->A (sequence variation 3), and P-->T (sequence variation 4) were identified by sequencing of polymerase chain reaction products and studied by minisatellite variant repeat analysis for their incidence and topology in the 5' and 3' peripheral regions of the variable number of tandem repeats domain. Minisatellite variant repeat analyses were performed with 27 individual samples of genomic DNA from human cells and tissues covering 30-60% of the domain. Within the peripheral regions, sequence variations 1-4 occur at high incidence and show a nearly constant repeat topology in all individual normal and tumor samples. Also, individuals who were non-Caucasian or of different ethnic background were found to have the same set of replacements with identical topology. The repeat variant 1 replacing the established tumor target motif DTR with ESR was found in all individuals and appears predominantly in repeat clusters (diads and triads). The largely constant topology of variant repeats is interpreted by the assumption that the variable number of tandem repeats domain has evolved as a recent expansion of sequence variable super-repeats.

Alleles↗

PubMed2001

Isolation and characterization of a mouse monoclonal antibody against human corneal endothelial cells.

In vitro cultivation of human corneal endothelial cells (HCEC) is associated with loss of typical cobblestone-like appearance during successive passages. Thus far morphology was the sole criterion for the cell's endothelial nature. Mouse monoclonal antibodies (mabs) to human corneal endothelial cells were raised using standard immunization and hybridoma isolation procedures. The specificity of mabs for human corneal endothelial cells was tested in comparison to other endothelial cell types, to fibroblasts, corneal keratocytes and to human retinal pigmented epithelial cells. In addition immunofluorescence or immunoperoxidase staining was performed with frozen tissue sections of human corneas and with various other human tissues. The mab 9.3.E reacts with cultured human corneal endothelial cells, but not with cultured human fibroblasts and human keratocytes. In frozen sections selective positivity of corneal endothelium in contrast to negativity of the other corneal cell types was confirmed. In investigated extraocular tissues positivity was observed in smooth muscle cells including related cells (i.e. Ito and mesangial cells) and in Schwann's cells and adipocytes, but apparently not in vascular endothelial cells. The mab is human-specific and binds to a protein with a molecular weight of 130 kDa mainly accumulating along cell membranes. A mouse monoclonal antibody against human corneal endothelial cells was established in vitro and was shown to be capable of differentiating corneal endothelial cells from other corneal cell types, especially from corneal keratocytes. It is, however, not cornea-specific, but also reacts with certain extraocular cell types.

Adipocytes↗

PubMed2001

[Thermal ablation of liver metastases. Current status and prospects].

PURPOSE: To present thermal ablation of liver metastases via laser induced thermotherapy. MATERIAL AND METHODS: Different technical procedures of thermal ablation and online monitoring are used, as there are the MR-guided laser induced thermotherapy (LITT) and the radiofrequency ablation thermotherapy (RF). RESULTS: In a prospective non randomized study 606 patients with liver metastases were treated via MR-guided laser induced thermotherapy. Inclusion criteria were the exclusion of extrahepatic tumor spread and a number of metastases lower than 5 and a size lower than 50 mm in diameter. The local tumor control rate in the 3 month and 6 month control study was 98.3%, the complication rate 3.5% (clinically relevant: 1.2%). The mean survival rate was 40.9 months for all patients with liver metastases without statistically relevant differences for various primaries, like colorectal carcinoma, breast cancer and various other tumors. Results for radiofrequency are so far limited with incidence of a higher local tumor recurrence rate versus LITT. CONCLUSION: MR-guided LITT results in a high local tumor control rate with improved survival.

Adult↗

PubMed2001

[Transarterial chemoembolization (TACE) of liver metastases. A palliative therapeutic approach].

Metastatic involvement of the liver determines the treatment. Hepatic artery chemoembolization (TACE) represents a safe palliative treatment for patients with unresectable liver metastases. Technical treatment, indication and results of the TACE are reported. The results of TACE depend on primary cancer, size and vascularisation of the hepatic tumors. Our results with out patient treatment of 245 patients prove that TACE results in a extremely low rate of side effects. Combination of TACE with local ablative treatment may present potentially curative treatment option for unresectable tumors.

Adult↗

PubMed2001

[Transarterial chemoembolization in hepatocellular carcinomas: technique, indications, results].

BACKGROUND: At time of diagnosis 80% of the patients with hepatocellular carcinoma (HCC) could not be treated with surgical treatments, so that transarterial chemoembolization (TACE) was used as an neoadjuvant or palliative treatment modality. MATERIAL AND METHODS: 60 patients were treated with 217 TACE courses, in the mean 3.6 TACE treatments per patient with an 4 week interval. TACE was performed with a dispersion of lipiodol, mitomycin C and spherex. 11 patients (18.3%) were treated in a neoadjuvant protocol with successful ablation. Lipiodol retention and size of the tumors were evaluated by CT and MRI. RESULTS: 60 patients were successful treated with TACE. After treatment a primary high lipiodol retention was displayed and in 68 (63.3%) patients a reduction of the tumor size and in 11 (20%) patients a reduction of tumor growth rate was noted. The 1 year survival rate was 59%. After response to TACE and reducing the tumor size 11 patients could be treated with MR-guided LITT 4 to 6 weeks post embolization. CONCLUSION: Chemoembolization is a minimal invasive and outpatient treatment protocol for HCC. TACE might be indicated as a palliative treatment to control the diseased liver. If repeated TACE alters the size and structure of primary unresectable HCC TACE expands the indication for MR-guided LITT.

Adult↗

PubMed2001

[Oligonodular hepatocellular carcinoma (HCC): MR-controlled laser-induced thermotherapy].

PURPOSE: To prospectively evaluate the therapeutic potential of MR-guided laser-induced thermotherapy (LITT) in patients with oligonodular hepatocellular carcinoma. MATERIAL AND METHODS: 39 patients with 61 intrahepatic lesions were treated with LITT. The Nd:YAG laser fiber was introduced with a percutaneously positioned irrigated laser application system. Qualitative and quantitative MR parameters and clinical data were evaluated. RESULTS: All patients tolerated the procedure well under local anesthesia. All observed complications were minor and no further treatment was necessary. Online MR thermometry allowed exact visualization. Lesions up to 2 cm in diameter could be efficiently treated with a single laser application, larger lesions were treated simultaneous multiapplication. In 97.5% we achieved a complete necrosis of the tumor and a 5 mm safety margin, resulting in a complete destruction of the tumor without local recurrences. Mean survival was 4.4 years (95% CI: 3.6-5.2 years) after the time of diagnoses of the HCC (Kaplan-Meier-method). CONCLUSION: In intrahepatic oligonodular involvement of hepatocellular carcinoma LITT appears to be an effective therapeutic procedure with a high tumor control rate and better survival data.

Adult↗

PubMed2001

[Correlation of 55 samples of contact lens fluid and direct swabbings of the eye surface of symptomatic wearers of contact lenses].

BACKGROUND: The microbiological examination of contact lens storage solutions may reveal the etiological organisms responsible for keratitis and additionally harbour environmental contaminants. PATIENTS AND METHODS: From 1995 to 1998, conjunctival and corneal smears and scrapes, as well as the storage solutions of 55 soft contact lens wearers were examined microbiologically in a prospective non-randomised cohort study involving 53x unilateral and 2x bilateral cases of keraitis. RESULTS: In 42 of the in-use contact lens storage solutions, the following organisms were found: 8x Bacillus sp., 7x P. aeruginosa and 8x other pseudomonads, 6x Alcaligenes xylosans, 4x Serratia liquefaciens, 4x Enterobacter sp., 4x coagulase negative staphylococci, 3x Serratia marcescens, 3x S. aureus, 2x Streptococcus faecalis, 1x Klebsiella oxytoca and 5x Acanthameba. A significant correlation of ocular cultures was found for Pseudomonas, Enterobacter, Serratia, S. aureus, S. faecalis and Acanthameba, but not for Bacillus, Alcaligenes, and coagulase negative staphylococci. Fungi were not found. The more pronounced the clinical picture, the more Gram-negative bacteria were isolated. CONCLUSIONS: The microbiological examination of soft contact lens storage solutions of 55 keratitis patients confirmed that the microbes responsible were to be found in the fluid, in addition to environmental contaminants.

Acanthamoeba Keratitis↗

PubMed2001

[Immunosuppressive therapy with mycophenolate mofetil (CellCept) in treatment of uveitis].

BACKGROUND: Severe forms of uveitis can often only be managed sufficiently with systemic immunosuppression. All available drugs are known for their relative high rate of side-effects. Mycophenolate mofetil (MMF), an immunosuppressant successfully used in management after organ transplantation and many autoimmune diseases, has shown remarkably less side-effects when used for various forms of uveitis in monotherapy or in combination with corticosteroids. The aim of this multicenter-study was to investigate if monotherapy with MMF is effective in various forms of uveitis. METHOD AND PATIENTS: Ten patients with anterior uveitis (n = 3), intermediate uveitis (n = 2), panuveitis (n = 4) and retinal vasculitis (n = 1) were treated in a prospective study with 2 x 1 g MMF daily. Previous immunosuppression had been discontinued because of side-effects or ineffectivity in all patients. In these patients MMF was given in addition to the other immunosuppressant at the beginning of treatment. RESULTS: The follow-up time ranged from 1 to 12 months (mean 4.5 months). Under therapy with MMF (monotherapy in 4 patients, additional prednisolone in 5 patients and additional metotrexate in 1 patient) 8 patients remained free of recurrences. In one female patient depression of inflammation activity was only achieved after cessation of therapy with Cyclosporin A in combination with MMF and a switch to methotrexate. Another patient with a bilateral uveitis was free of recurrences in only one eye, the second eye did not develop recurrence due to the additional corticosteroid treatment. Side-effects were diarrhoea in one patient and probably gastrointestinal problems in another (leading to cessation of therapy in both patients) and in another case nausea, vomitus and alopecia 10 months after beginning therapy. CONCLUSIONS: MMF as a new immunosuppressant stopped inflammation or drastically reduced the rate of recurrences in 8 out of 10 patients with uveitis which was previously not brought under control by other immunosuppressants. The side-effects were tolerable in comparison with other immunosuppressive agents. More patients, longer follow-up times and a comparative study with Cyclosporin A are required to assess the long-term therapeutical success.

Adult↗

PubMed2001

[Follow-up of endothelial cell density after perforating keratoplasty. Effect of donor and recipient-related factors].

PURPOSE: Endothelial cell loss can be observed after keratoplasty, therefore in a retrospective study we analysed whether there is a correlation between donor age, recipient age, time post-mortem, preoperative cell density, diagnosis of the recipient and postoperative endothelial cell density. METHODS: The endothelial cell densities of 120 patients who had undergone penetrating keratoplasty were examined over a period of 2 years. We divided the patients into four groups based on the endothelial cell density over 2 years. We examined the groups with regard to the parameters given above. RESULTS: The lowest postoperative cell densities 2 years after keratoplasty showed a high correlation with the highest donor and recipient age. Even the lowest preoperative cell density was found in this group. Patients who underwent keratoplasty because of keratoconus had the highest cell densities after 2 years and also the lowest donor and recipient age. The preoperative cell density was also highest in this group. DISCUSSION: The results indicate a correlation between increasing donor and recipient age, decreasing preoperative cell density and loss of endothelial cells 2 years after penetrating keratoplasty. Patients with the diagnosis keratoconus should also receive transplants with higher donor age.

Adult↗

PubMed2001

Evaluation of potential organ culture media for eye banking using a human corneal endothelial cell growth assay.

BACKGROUND: To evaluate the ability of different commercially available cell culture media to induce proliferation and morphological changes in primary cultures of human corneal endothelial cells (HCEC). This screening model was used in an attempt to establish a rational basis for the development of well-defined, serum-free preservation media for long-term organ culture of human donor corneas. METHODS: A total of 11 different culture media enriched with 0%, 2%, 5%, and 10% fetal calf serum (FCS) were compared. The test media were divided into three groups: Group 1: Media based on minimal essential medium (MEM), currently used for long-term corneal organ culture in European eye banks; Group 2: F99-based media, enriched for growth of corneal endothelial cells at serum-reduced conditions; and Group 3: Media designed for growth of special cell types or for short-term corneal organ culture. The growth-promoting capacity of each test medium was quantified using an HCEC proliferation assay, whereas changes in cell morphology were evaluated by phase-contrast microscopy. RESULTS: The morphological characteristics of HCEC were best maintained in the group of F99-based media, which also induced the highest level of cell proliferation under serum-reduced conditions. Specifically, the medium F99-Sr (F99 enriched with ascorbic acid, insulin, bFGF, transferrin, selenium, and lipids) induced a two- to three-fold higher HCEC density at both 0% and 2% FCS when compared to all other test media, and it also maintained the most endothelial cell-like morphology. Also, at higher serum concentrations (5% and 10% FCS), the cell growth was most prominent in F99-Sr, as well as in the medium SFM that originally was designed for serum-free growth of vascular endothelial cells. CONCLUSION: This study suggests that the media F99-Sr and SFM should be further tested and refined as potential new storage solutions for long-term corneal organ culture at physiological temperatures.

Aged↗

PubMed2001

Use of a serum-free medium for long-term storage of human corneas. Influence on endothelial cell density and corneal metabolism.

BACKGROUND: The success of long-term corneal organ culture is limited by the progressive loss of endothelial cells during culture and the use of culture medium supplemented with fetal calf serum as a possible source of contamination with infectious agents. In this study, we investigated the suitability of a serum-free medium (Endothelial-SFM) to improve preservation conditions for human donor corneas. METHODS: Six pairs of corneas were stored in Minimum Essential Medium (MEM) supplemented with 2% fetal calf serum (FCS) for 8-14 days. One cornea of each pair was then further cultivated in Endothelial-SFM supplemented with 2% FCS or in MEM with 2% FCS, respectively. In a second series of experiments, the endothelial cell density of seven pairs of freshly isolated donor corneas was determined during cultivation in Endothelial-SFM with 2% FCS or serum-free Endothelial-SFM. RESULTS: After precultivation in conventional medium, the endothelial cell density of corneas allocated to cultivation in Endothelial-SFM was 1000-1950 cells/mm2 and that of those subsequently cultured in MEM 1200-2000 cells/mm2. At 9 weeks, cell densities of 900-1500 cells/mm2 were found after cultivation in Endothelial-SFM compared with a total cell loss in MEM. Freshly isolated corneas cultured in Endothelial-SFM with or without FCS supplementation showed a decrease of endothelial cell density of about 20% within the first 2 weeks of storage. During further cultivation cell density remained constant without statistically significant differences between the groups. Glucose consumption of the corneas was higher in Endothelial-SFM than in MEM. Corneas stored in Endothelial-SFM with 2% FCS showed a higher glucose consumption than those preserved in serum-free Endothelial-SFM. CONCLUSION: Organ culture of human donor corneas using the serum-free basal medium Endothelial-SFM is superior to conventional culture conditions because the decrease in endothelial cell density can be ameliorated, the culture period can be prolonged and the risk of transmitting infectious agents via serum can be minimised.

Aged↗