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Biomedical subjects

K M Kreusel

Publications and source records attributed to K M Kreusel.

At least 19 recordsLinked to original sources
PubMed2004

[Endoresection following proton beam irradiation of large uveal melanomas].

PURPOSE: Large uveal melanomas located close to the optic nerve and/ or to the fovea have an unfavourable prognosis with regard to visual preservation and eye retention, due to the high incidence of radiation and tumour necrosis induced complications. Endoresection of the tumour after proton beam irradiation, is an alternative approach, aiming to reduce the incidence of ocular morbidity caused by tumour necrosis after sole radiotherapy. PATIENTS AND METHODS: 32 patients with large uveal melanomas (mean tumour thickness: 9.1 mm, mean tumour volume: 0.77 cc), received a primary proton beam irradiation (60 CGE) and underwent subsequent endoresection via a 3-port pars plana vitrectomy. The median pretreatment visual acuity was 0.2. The mean follow-up was 13.9 months. RESULTS: The postoperative visual acuity after 12 months was 0.12 (median, mean visual acuity loss 0.08). The probability of developing radiation retinopathy or papillopathy within the first year after treatment was 35% and 28% respectively and the probability of enucleation was 9% within the first postoperative year. No tumour recurrences were observed and 2 patients developed liver metastases. CONCLUSIONS: Endoresection following irradiation of large uveal melanomas located close to the optic nerve and/ or the fovea seems to be a useful and safe alternative to the traditional irradiation or enucleation. The incidence of complications following our approach seems to be lower when compared to radiation alone, where tumour necrosis is a substantial problem.

Combined Modality Therapy↗
PubMed2002

[Indocyanine green angiography in choroid metastases].

BACKGROUND: Up to now the diagnosis of choroidal tumors was mainly based on ophthalmoscopy and ultrasound examination. Indocyanine green angiography allows the identification of vascular patterns in these tumors, which could be helpful in the differential diagnosis. The aim of the study was to characterize the staining patterns of choroidal metastases. METHODS: In the years 1996-2000 we performed ICG-A of 15 choroidal metastasis using the scanning laser ophthalmoscope from Rodenstock. The mean tumor height was 3.7 mm (2.0-9.0). These angiographies were compared to the angiographies of 38 choroidal malignant melanomas with a mean height of 3.6 mm (1.4-6-6). RESULTS: All metastases showed a blockage of the background staining and a patchy staining of the tumor surface. Intratumoral vessels could be detected in 13% of all cases of metastases. The choroidal melanomas examined showed a blockage of the background staining in all cases and tumor vessels in 89%. CONCLUSION: The angiographic picture of the metastatic lesions was characteristic. Intratumoral vessels could not be detected using ICG-A. Most of the metastases showed a patchy staining of the tumor surface.

Angiography↗
PubMed2001

[Vitrectomy in advanced Coats disease].

BACKGROUND: Coats disease is a retinal vasculopathy of unknown cause. Untreated cases usually lead to an exudative retinal detachment and rubeosis iridis with secondary glaucoma. Photocoagulation and/or cryotherapy are generally the first interventions in treating the disease. Pars plana vitrectomy may be indicated in cases of vitreous hemorrhage or retinal detachment. METHODS: We performed pars plana vitrectomy in 9 eyes with Coats disease between 1992 and 1999. A retinal detachment was present in 3 cases, and three showed a vitreous hemorrhage. In two cases surgery was indicated because of paramacular localization of the pathological vessels with associated exudations. RESULTS: The two cases with paramacular involvement showed improvement in visual acuity of eight lines. In the remaining cases visual acuity remained within two lines compared to the initial visual acuity. All eyes except one could be saved. CONCLUSION: Pars plana vitrectomy is a useful option in treating advanced Coats disease, especially in cases associated with vitreous hemorrhage or retinal traction.

Adolescent↗
PubMed2000

[Intraocular metastases of metastatic breast carcinoma in the woman. Incidence, risk factors and therapy].

BACKGROUND: The breast cancer metastasis is the most common intraocular tumor in females. Aim of this study was to determine incidence and risk factors for intraocular metastasis and to evaluate the benefit of an early treatment. PATIENTS AND METHODS: 151 patients suffering from metastatic breast cancer were screened for the presence of intraocular metastasis. The medical history and the tumor status at the time of screening were evaluated and risk factors for intraocular metastasis were determined. In case of choroidal metastasis external beam radiotherapy was performed. RESULTS: Intraocular metastasis was found in 7 out of 151 patients screened (4.6%). In one patient metastasis was located in the iris, in 6 patients in the choroid. Intraocular metastasis was only found in patients with more than one other organ system involved into disease (p = 0.002). In this subgroup of patients (n = 65) prevalence of intraocular metastasis was 10.8%. Other risk factors for intraocular metastasis were presence of lung metastasis or brain metastasis. In 5 out 6 patients with choroidal metastasis external beam radiotherapy was performed, resulting in durable regression of metastasis and stabilization or improvement of visual acuity. CONCLUSION: The prevalence of intraocular metastasis in metastatic breast cancer was determined to be 4.6%. It is most commonly located in the choroid and develops in the course of advanced metastatic disease. Since early external beam radiotherapy of choroidal metastasis prevents functional loss, patients at risk should be given an ophthalmological screening for intraocular metastasis.

Adult↗
PubMed2000

Retinal angiomatosis and von Hippel-Lindau disease.

BACKGROUND: To evaluate the significance of angioma number (single or multiple) for the presence of von Hippel-Lindau (VHL) disease in patients presenting with capillary retinal angioma. METHODS: Forty-one nonrelated patients presenting with capillary retinal angioma were evaluated. An ophthalmic workup, screening for other organ lesions, and molecular genetic screening for a mutation of the VHL gene was performed. The diagnosis of VHL was made on the basis of the personal and family history, the presence of other VHL-associated organ lesions, or the presence of a mutation of the VHL gene. RESULTS: Thirteen patients (32%) presented with a single angioma and 28 patients (68%) presented with multiple angiomas. In 81% of all patients, VHL could be diagnosed. Diagnosis of VHL could be readily made by the personal or family history in 51% of all patients. In another 27% of all patients, VHL disease was evidenced by screening for other VHL-associated lesions. In two patients (3%) VHL could be diagnosed by molecular genetics only. All patients with multiple retinal angiomas had VHL disease and, in 38% of patients with a single angioma, VHL was present. Reasons for a missing family history in patients with VHL disease were the presence of a de novo mutation (15% of VHL patients) or clinical anticipation of VHL disease (18% of VHL patients). CONCLUSION: The presence of multiple retinal angiomas strongly suggests VHL disease, which, however, can be obscured by presence of a de novo mutation or by clinical anticipation of VHL disease in affected families. A single retinal angioma may be sporadic as well as the presenting sign of VHL. Diagnosis and screening for this multitumor syndrome is substantially supported by molecular genetics.

Adolescent↗
PubMed1999

[Retinal capillary angioma. Clinical and molecular genetic studies].

UNLABELLED: Capillary retinal angiomas are rare vascular tumors that frequently occur in von Hippel-Lindau syndrome (vHL) but may also be sporadic. In all patients presenting with this tumor a thorough search for other vHL-associated lesions must be performed. After identification of the vHL gene on the short arm of chromosome 3 (3p25-26), the diagnosis is supported by molecular genetic analysis. PATIENTS: In 20 patients with retinal angioma a clinical search for other manifestations of vHL was performed. In 5 patients only one angioma was present. In all patients molecular genetic tests for a mutation of the vHL gene were performed by SSCP and direct sequencing. RESULTS: In 16 (80%) patients vHl was present, and in 15 it could be diagnosed by clinical findings or a positive family history. Organ lesions in vHL patients were CNS hemangioblastoma in 10 (63%), pancreatic cysts in 7 (43%) and renal cysts in 7 (43%) patients. In two patients (13%) renal carcinoma could be detected; in one patient a pheochromocytoma was present. A mutation could be detected in all 15 patients with clinically confirmed vHL. In three patients a new mutation of vHL disease was diagnosed genetically. In one of these patients a single retinal angioma was the only sign of vHL. CONCLUSION: In patients presenting with capillary retinal angioma a careful search for other vHL lesions has to be performed. A mutation of the vHL gene can be detected in the majority of patients; thus, molecular genetic testing is a powerful tool for diagnosis and detection of asymptomatic gene-carriers.

Adolescent↗
PubMed1999

Choroidal metastasis in men with metastatic breast cancer.

PURPOSE: To report two cases of choroidal metastasis in metastatic breast cancer in men. METHOD: Case reports of a 50-year-old man with an 8-year history of breast cancer who was initially examined with a solitary amelanotic choroidal tumor and a 62-year-old man with an 8-month history of breast cancer who was initially examined with numerous unilateral amelanotic choroidal tumors. RESULTS: Ophthalmoscopic and echographic characteristics of the choroidal tumors were typical for breast cancer metastasis. Systemic screening disclosed advanced metastatic disease in both patients. Choroidal metastasis could be effectively treated by external beam irradiation. CONCLUSIONS: Although breast cancer is a rare condition in men, it should be considered as a possible primary cancer in cases of choroidal metastasis.

Bone Neoplasms↗
PubMed1999

Radiotherapy of unilateral choroidal metastasis: unilateral irradiation or bilateral irradiation for sterilization of suspected contralateral disease?

Radiotherapy is the highly effective standard in the treatment of choroidal metastasis. Visual acuity can be stabilized or increased in about 70-80% of eyes treated, thus prevailing the quality of life in these worse prognostic patients. In about 30-40% bilateral macroscopic disease is found at diagnosis. The best treatment for unilateral metastasis remains controversial: unilateral or bilateral irradiation for sterilization of suspected contralateral metastasis or unilateral irradiation without irradiation of the contralateral choroidea. In the analysis of a prospective study (ARO 95-08) 35 out of 50 patients with choroidal metastasis had unilateral disease and received unilateral irradiation with a lateral field using 6 MeV-photons (40 Gy in 20 fractions) without sparing the contralateral choroidea. Therefore the posterior contralateral choroidea received 50-70% of the total dose (20-28 Gy) for suspected micrometastasis. None of these patients developed contralateral choroidal metastasis during the median follow up time of 11.5 months. A unilateral field with 40 Gy for unilateral choroidal metastasis without sparing the contralateral choroidea seems to be effective in destroying contralateral micrometastasis with a lower risk of late side effects compared with bilateral fields.

Adult↗
PubMed1998

Ruthenium-106 brachytherapy for peripheral retinal capillary hemangioma.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of ruthenium-106 brachytherapy of large peripheral retinal capillary hemangiomas. DESIGN: A retrospective case series. PARTICIPANTS: In 25 eyes of 24 patients, peripheral capillary retinal hemangiomas were treated. INTERVENTION: Brachytherapy using 106-ruthenium/106-rhodium plaques was performed. MAIN OUTCOME MEASURES: Eyes were reviewed for hemangioma regression after brachytherapy, occurrence of retinal detachment, requirement of additional vitreoretinal surgery, final visual outcome, and final retinal status. RESULTS: Preoperative mean visual acuity of all eyes treated was 20/60, mean hemangioma diameter was 3.8 mm, corresponding to approximately 2 disc diameters. In 14 eyes, the retina was attached before surgery, 8 eyes showed an exudative detachment, and 3 eyes showed a traction detachment. Fifteen patients had definite von Hippel-Lindau syndrome. Twenty-three of 25 hemangiomas could be destroyed by single brachytherapy. In 16 eyes, a favorable outcome could be achieved. In nine eyes, outcome was unfavorable, characterized by a severe drop in visual acuity, a persisting exudative retinal detachment, or a recurrent traction detachment. In one eye requiring repeated brachytherapy, irradiation retinopathy occurred. Hemangiomas up to a size of approximately 5.0 mm without preoperative exudative detachment could be treated safely by brachytherapy, whereas a larger hemangioma size or a pre-existing exudative retinal detachment predisposed to an unfavorable outcome. CONCLUSION: Solitary peripheral retinal hemangioma can be ablated effectively by ruthenium-106 brachytherapy. A favorable outcome can be expected if the hemangioma diameter is 5.0 mm or smaller and if there is no preoperative exudative retinal detachment.

Adolescent↗
PubMed1998

Frequency of asymptomatic choroidal metastasis in patients with disseminated breast cancer: results of a prospective screening programme.

AIM: To determine the frequency of visually asymptomatic choroidal metastasis in patients with disseminated breast cancer and its dependence on the incidence of metastasis by number and site of other organ metastases. METHODS: From January 1995 until April 1997 120 patients irradiated for disseminated breast cancer underwent ophthalmological screening for choroidal metastasis. No patient was symptomatic for ocular disease. 68 out of 120 patients were found to have metastases in one organ and 52 patients had metastases in more than one organ. 80% of the patients had bone metastases, 25% lung metastases, 22% liver metastases, 15% brain metastases, and 22% had metastases in other organs. RESULTS: Six patients (5%) were found to have asymptomatic choroidal metastases. Five patients had unilateral and one patient bilateral metastases. 52 patients with more than one involved organ had a significantly higher risk for asymptomatic choroidal metastasis (6/52, 11%) than 68 patients with metastases in only one organ (0/68) (p = 0.006). In univariate analysis a significantly higher risk was seen for patients with lung metastases (14% choroidal metastases versus 2% in patients without lung metastases, p = 0.03) and for patients with brain metastases (17% choroidal metastases versus 3% in those without brain metastases, p = 0.04). CONCLUSION: In disseminated breast cancer the incidence of asymptomatic choroidal metastases was 5% and increased to 11% when more than one organ was involved in metastatic spread. Risk factors for choroidal metastases were dissemination of disease in more than one organ and the presence of lung and brain metastases.

Adult↗
PubMed1997

Differential stimulation of intestinal mucin secretion by cholera toxin and carbachol.

Cholinergic stimulation triggers the secretion of apically stored, preformed mucin from goblet cells but the pathway of cAMP-stimulated mucin secretion is not known. In this study the effect of cholera toxin on mucin secretion in the human colonic goblet cell line HT-29/B6 was investigated and compared to the action of carbachol. PAS staining of mucin blotted onto nitrocellulose served to quantify the secretion of total mucin. Metabolic labelling was used to evaluate the secretion of newly synthesized mucin. The mucinous nature of the detected material was confirmed with an immunoblot employing a well-characterized polyclonal antibody reacting with MUC2-mucin. Cholera toxin caused a 116-fold increase of intracellular cAMP and strongly stimulated the secretion of both preformed and newly synthesized mucin for more than 20 h. Carbachol only triggered the release of preformed mucin immediately after addition. The secretory response to cholera toxin could be partly inhibited by the protein kinase A inhibitor H8 and the microtubule inhibitor colchicine. The action of carbachol was not affected by these agents. In conclusion, we demonstrate a direct cAMP-dependent effect of cholera toxin on mucin secretion by intestinal goblet cells. In contrast to carbachol, the action of cholera toxin involves de novo synthesis of mucin molecules and microtubule-mediated secretion. There seem to be distinct secretion pathways for muscarinic or cAMP-dependent stimulation of mucin secretion.

Calcium↗
PubMed1994

Tight junctions and paracellular permeability in cultured bovine corneal endothelial cells.

Intramembrane specializations of cultured bovine corneal endothelial cells were studied with thin section and freeze-fracture electron microscopy and related to the paracellular permeability and the transendothelial resistance (Rt) of the monolayers. The following intercellular junctions were found: single and discontinuous networks of tight junctions (TJ) which girdle the apico-lateral cell perimeter incompletely, gap junctions, and membrane undulations suggesting intermediate junctions. The macromolecular tracer ruthenium red penetrated into the lateral intercellular space beyond the level of the incomplete belt of TJ. Rt of these monolayers was 20.9 +/- 1.0 omega.cm2. Protamine induced a reversible increase of Rt to 118 +/- 5% of its control value. We conclude that incomplete belts of TJ may be the morphological counterpart of the high paracellular permeability of this monolayer and functionally and morphologically resemble those of their native endothelium. Cultured corneal endothelial cells are an excellent model for studying the influence of incomplete belts of TJ on paracellular permeability of cells.

Animals↗