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Biomedical subjects

W Lieb

Publications and source records attributed to W Lieb.

At least 19 recordsLinked to original sources
PubMed2004

Loss of nonclassical MHC molecules MIC-A/B expression during progression of uveal melanoma.

Uveal melanoma differs from cutaneous melanoma with respect to aetiology, metastatic behaviour and immune biology. The notion that loss of classical MHC class I molecules in uveal melanoma lesions is associated with an improved prognosis suggests that NK cells act as the predominant cells responsible for immune surveillance of this tumour. Consequently, immune escape mechanisms of uveal melanoma should impair the innate immunity. To this end, expression of the ligand for the NK receptor NKG2D, that is, MIC-A/B was expressed by 50% of primary tumours, but none of the metastatic lesions. MIC+ tumours were characterised by a NKG2D+ infiltrate, which was absent in MIC- lesions subsequent to chemoimmune therapy. Strikingly, MIC-A/B expression in metastatic lesions was observed subsequent to chemotherapy with fotemustine in one case. In summary, MIC/NKG2D interactions seem to be involved in the immune surveillance of primary uveal melanomas, whereas for metastatic tumours this ligand/receptor system seems not to be relevant, thus, suggesting an immune selection of MIC negative tumour cells.

CD57 Antigens↗
PubMed2004

[Criswick-Schepens syndrome -- familial exudative vitreoretinopathy. Report of six cases in two consanguineous families].

BACKGROUND: Familial exudative vitreoretinopathy is a hereditary, bilaterally progressive formation of a vitreoretinal membrane. It usually occurs in full-term newborns without previous treatment with hyperbaric oxygen. In this report, we present six cases of this disease with various abnormalities of the posterior segment diagnosed in two Syrian families related by first degree of consanguinity. DESIGN: A retrospective family analysis and presentation of cases. CASE PRESENTATION: Six members of the two consanguineous families, aged between 3.5 and 13 years, who were systemically healthy, presented with a visual acuity ranging between light perception and 0.4 with bilateral fundus changes. The findings included: papillary, macular, and retinal temporal traction in 11 eyes, a retinal fold in 7 eyes, a fibrovascular mass in 11 eyes, vitreoretinal traction in 5 eyes, subretinal exudation in 2 eyes, pigmentary abnormalities in 2 eyes, temporal or total tractional retinal detachment in 2 eyes, and vitreous hemorrhage in 1 eye. SUMMARY: Familial exudative vitreoretinopathy is characterized by fundus changes that resemble retinopathy of prematurity and must be differentiated from other diseases (e.g., Coats' disease, incontinentia pigmenti, persistent hyperplastic primary vitreous, and Norrie's disease).

Adolescent↗
PubMed2003

[Immunochemical demonstration of human herpes virus 8 in conjunctival Kaposi's sarcoma].

BACKGROUND: Angiomatous lesions of the conjunctiva and chronic conjunctivitis are frequently difficult to differentiate. CASE: A 28 year old white male sought help because of a conjunctival swelling. A biopsy made elsewhere had revealed a capillary haemangioma of the conjunctiva. Recently striking alterations of the skin led to the suspicion of a Kaposi's sarcoma. Immunohistochemical and dermatological examinations confirmed the diagnosis of a Kaposi's sarcoma and viral testing of serum revealed an HIV-infection. Besides intensive antiviral therapy, our patient underwent local irradiation of the right eye, the nose and of the left shoulder with an external beam. CONCLUSIONS: Kaposi's sarcoma is the most frequent Aids-associated malignant tumor. In about 30% of all patients with Aids, a Kaposi's sarcoma is diagnosed. The angiomatous character may lead to the histopathological diagnosis of a haemangioma. Human herpes virus 8 is known to be the transforming element.

AIDS-Related Complex↗
PubMed2002

Treatment of disseminated ocular melanoma with sequential fotemustine, interferon alpha, and interleukin 2.

Malignant melanoma of the uvea is remarkable for purely haematogenous dissemination and its tendency to metastasise to the liver. Although the liver is involved in up to 95% of patients, 50% of these also develop extrahepatic metastases, most often in the lungs, bone, skin, and brain. The only effective treatments reported to date relied on hepatic arterial chemoembolisation or -perfusion. The objective of this study was to establish a therapy protocol addressing patients with both sole liver involvement and systemic disease. Forty-eight patients with metastatic ocular melanoma received fotemustine 100 mg m(-2) either as 60-min infusion into the hepatic artery or as 15-min infusion via a peripheral vein, depending on the metastatic sites involved, i.e., restriction to the liver or hepatic together with extrahepatic disease. For the first treatment cycle this infusion was repeated after one week. For all cycles, subsequent to a three week resting period, patients received an immunotherapy consisting of subcutaneous interleukin 2 and interferon alpha(2). Although objective responses were more frequent within the cohort receiving intraarterial fotemustine (21.7 vs 8%), this difference did not translate into a significant benefit in overall survival, i.e., 369 and 349 days, respectively. Of note, this overall survival is much longer than that repeatedly reported for stage IV uveal melanoma not treated with fotemustine, suggesting a therapeutic activity of this cytostatic drug even after systemic administration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Soft X-ray therapy of recurrent pterygium--an alternative to 90Sr eye applicators.

BACKGROUND: Analysis of effectiveness of perioperative 20 kV soft X-ray irradiation in recurrent pterygium as an alternative to postoperative 90Sr beta irradiation. PATIENTS AND METHODS: Between 1987 and 2000 a total of 65 patients with 81 pterygia were treated with 20 kV X-ray therapy in the course of surgical treatment of recurrent pterygium. Until 1995 simple excision (bare sclera technique) followed by postoperative irradiation (generally four fractions of 5 Gy) was applied, with radiation starting on mean 4 days following surgery (34 cases, mean follow-up 52 months). Since 1995 we have changed our policy to a perioperative regimen starting with a single dose of 7 Gy prior to microsurgical excision with conjunctival autograft and proceeding within 24 hours with 5 Gy single dose to the surgical bed and then every other day to a total dose of 27 Gy (47 cases, mean follow-up 31 months). Recurrence rate was calculated by Kaplan Meier method. A multivariate Cox regression analysis of prognostic factors for recurrence was performed. RESULTS: A total of 19 recurrences were observed, 15 in the historical postoperative group and four in the perioperative group. Actuarial 2- and 5-year recurrence rate is 9% in the "new treatment group" compared to 34% and 56% in the historical group (p = 0.001). Only one of the four recurrences among the pre- and postoperatively irradiated group required a new surgical procedure. In this case radiation had been terminated at 17 Gy. Actuarial rate of surgical reintervention was only 2% at 2 and 5 years compared to 28% and 36% in the historical group. In multivariate Cox regression analysis only the new treatment strategy was found to influence control rate significantly. Until now no case of severe side effects like scleral necrosis or thinning, symble-pharon, radiation-induced cataract or glaucoma were observed in both groups. CONCLUSION: The combination of pre- and postoperative 20 kV X-ray therapy and microsurgical excision combined with conjunctival autograft is a highly effective treatment to prevent recurrence in the high-risk group of recurrent pterygia and can be recommended as an alternative to postoperative 90Sr beta irradiation.

Actuarial Analysis↗
PubMed2001

[Dynamic MRI imaging of orbital diseases and ocular motility disorders].

High temporal and spatial resolution has recently been achieved by rapid magnetic resonance imaging techniques. This offers the opportunity to perform dynamic magnetic resonance imaging in addition to topographic imaging and tissue analysis. Using sequences obtained by turbo-fast low-angle shot imaging we have reduced temporal resolution to 1 s per image.

Adult↗
PubMed2001

Transvenous embolization of carotid cavernous fistulas via the superior ophthalmic vein.

BACKGROUND: Treatment of choice for symptomatic carotid-cavernous and cavernous-dural fistulas is neuroradiologic intervention via the femoral artery. Owing to the location of the fistula and/or to anatomic variations, a direct surgical approach via the superior ophthalmic vein may be necessary for embolization. METHODS: Three patients presented with exophthalmos, episcleral venous congestion, chemosis, restricted eye movement, and secondary glaucoma. One patient had visual impairment and scotoma due to compression of the optic nerve by the fistula. The tentative diagnosis of an arteriovenous fistula was confirmed in two cases by color Doppler imaging and in all three cases with cerebral arterial angiography (two carotid-cavernous fistulas, one cavernous-dural fistula). After an unsuccessful transarterial attempt, embolization via the superior ophthalmic vein was chosen. RESULTS: In all three patients the preparation of the superior ophthalmic vein was performed without any complications. In two cases the fistula could be embolized completely with platinum coils. In one patient the placement of the microcatheter was impossible, because of an abnormal vascular pattern. Later on the fistula was successfully embolized by an approach via the femoral vein. All three patients had complete resolution of symptoms. There were no recurrences. CONCLUSION: Embolization of carotid-cavernous and cavernous-dural fistulas by a surgical approach via the superior ophthalmic vein represents safe and effective treatment when standard transarterial access is impossible. The cooperation of an orbital surgeon and an invasive neuroradiologist can be of benefit for this rare group of patients.

Aged↗
PubMed2000

[Reconstruction of the medial canthal eyelid. Methods, problems and outcome].

BACKGROUND: Histologically controlled excision of medial canthal eyelid tumors often creates large skin defects, which may be closed by various reconstruction techniques. PATIENTS AND METHODS: To obtain information about indications for surgery, complications, and esthetic and functional results we analyzed 39 of our patients who underwent surgery in this area between August of 1995 and January 1998. RESULTS: Four small defects were closed primarily. A free full-thickness skin graft was used in 15 patients with a medium-sized defect, and 18 patients with large defects were handled by a local rotation or transposition flap. Granulation was left to occur spontaneously in two patients in poor general health. No tumor recurrences were seen. The functional and esthetic results were good. After 3 months free transplants and rotational flaps had healed in well. Increased scarring with mild medial ectropion was seen in five patients with rotation flaps. Patients who were left to spontaneous granulation required a more intensive and longer local treatment. CONCLUSIONS: For the reconstruction of medial canthal defects after tumor excision, free skin transplants were used for small to medium, and rotation flaps for large defects. These are successful procedures with good functional and esthetic results. Spontaneous granulation is an acceptable therapeutic alternative for patients in poor general health.

Aged↗
PubMed2000

Erbium-YAG laser-assisted preparation of deep sclerectomy.

BACKGROUND: Deep sclerectomy and viscocanalostomy are becoming more and more popular as non-penetrating filtering procedures. The purpose of the present study was to simplify the technique of this procedure and to reduce the rate of unintended perforations during the preparation of the deep lamella. METHODS: 20 enucleated porcine eyes were used. A superficial lamellar scleral flap with an area of 5x5 mm as for trabeculectomy was surgically prepared. Using a pulsed erbium:YAG laser the deep lamella (220 +/- 40 microm) with an area of 4x3 mm was removed. Ablation was performed with an energy of 40-100 mJ, a frequency of 1-10 Hz and a spot size of 500 microm and 1 mm (divergent beam). During the procedure the intraocular pressure was kept constant by continuous infusion. Finally the eyes were analyzed histologically. RESULTS: After initial trials it was possible to ablate the remaining deep corneoscleral lamella with the erbium:YAG laser without perforating into the anterior chamber. Starting with an energy of 70-85 mJ and a reduction to 40-60 mJ when reaching deeper layers, a spot size of 500 microm and a 10 Hz repetition rate gave the highest safety and efficiency in preparation. After a learning curve it was possible to preserve Descemet's membrane and intact trabecular meshwork in 10 consecutive operations as demonstrated by histology. CONCLUSION: Erbium:YAG laser-assisted deep sclerectomy offers an alternative to microsurgical preparation of the deep scleral lamella. The thermal damage is minimal (10-40 microm) and scarring may therefore not be stimulated.

Animals↗
PubMed2000

Ligneous conjunctivitis in a girl with severe type I plasminogen deficiency.

BACKGROUND: Ligneous conjunctivitis is a rare form of chronic recurrent pseudomembranous disease and may be associated with systemic membranous pathological changes. Recently ligneous conjunctivitis has been linked to severe type I plasminogen deficiency. We report on a patient with plasminogen deficiency and severe bilateral ligneous conjunctivitis. A new treatment approach and its outcome in this patient are described. CASE REPORT: We present the case of a 9-month-old Turkish girl with massive swelling of the eyelids and hard white pseudomembranes on both lids. The conjunctival smear was positive for Streptococcus pneumoniae. The clinical diagnosis was: ligneous conjunctivitis with superinfection. Histological investigation showed fibrin as major component of the pseudomembranes. The coagulation analyses revealed decreased plasminogen activity (<5%; normal 80-120%) and decreased plasminogen antigen (<0.4 mg/dl; normal 6-25 mg/dl). The failure of surgical therapy led to the attempt at treatment with intravenous lys-plasminogen. A significant improvement of the ocular symptoms occurred; stabilization with no recurrent pseudomembranes could be achieved for 6 months after treatment. DISCUSSION: The initial amelioration of symptoms in our patient after systemic replacement therapy confirms the etiological importance of plasminogen deficiency in the development of ligneous conjunctivitis. Curative treatment of ligneous conjunctivitis is still not available. However, intravenous application of plasminogen offers new possibilities in therapy, although long-term treatment seems necessary.

Conjunctiva↗
PubMed1999

A prospective randomized comparison of two techniques of combined cataract-glaucoma surgery.

BACKGROUND: Small-incision cataract surgery combined with trabeculectomy offers new options for surgical treatment of patients with glaucoma and cataract. The purpose of this prospective randomized study was to compare the efficacy and safety of two different techniques of combined surgery: a one-site and a two-site approach. METHODS: Fifty eyes of 50 patients were included in this study. Twenty-five patients were randomly assigned to the one-site procedure and 25 patients to the two-site procedure. The one-site approach consisted of a superior tunnel phacoemulsification under a scleral flap with subsequent trabeculectomy. The two-site approach included a temporal corneal phacoemulsification combined with a separate-incision superior trabeculectomy. RESULTS: The preoperative mean intraocular pressure (IOP) of 29.8+/-4.9 mmHg dropped significantly to 15.9+/-3.2 mmHg. The mean follow-up time was 19+/-4. 3 months (range 4-25 months). The reduction of IOP was more pronounced in the two-site group (50.1%) than in the one-site group (43%), but the difference was not statistically significant. Patients needed 2.2+/-1.7 antiglaucomatous medications preoperatively vs 0.52+/-1.39 postoperatively. Three patients (6%) required needling of encapsulated bleb, and two patients underwent a reoperation to control IOP. Mean visual acuity improved from 0. 14+/-0.36 to 0.38+/-0.30 postoperatively. The most common complications after combined surgery were fibrinous exudation (24%) and hyphema (12%). CONCLUSION: Both techniques of combined cataract and glaucoma surgery proved to be efficient and safe procedures to control IOP and to improve visual acuity. The reduction of IOP did not differ between the one-site approach and the two-site approach.

Aged↗
PubMed1999

Ocular manifestations in children and adolescents with Lyme arthritis.

BACKGROUND: Lyme arthritis is the most frequent late manifestation of Lyme borreliosis and has been associated with ocular inflammation. METHODS: A group of 153 children and adolescents with arthritis, 84 of whom had Lyme arthritis and 69 other causes of arthritis, were followed prospectively for 22-73 (median 44) months in the course of a national study. RESULTS: Three of 84 patients with Lyme arthritis had ocular inflammation (4%), including keratitis, anterior uveitis, and uveitis intermedia. All three had symptoms of decreased visual acuity. Whereas anterior uveitis disappeared without sequelae, a corneal scar and a permanent loss of visual acuity in the patients with keratitis and intermediate uveitis remained. Systematic examination of all patients revealed no further ocular involvement. Of 69 patients with other causes of arthritis who were followed in parallel as a control group, four of 15 patients with early onset pauciarticular juvenile rheumatoid arthritis had chronic anterior uveitis and two of 12 patients with juvenile spondyloarthropathy had acute anterior uveitis. CONCLUSIONS: Ocular involvement with keratitis, anterior uveitis, and intermediate uveitis may occur in children and adolescents with Lyme arthritis. Visual loss appears to be symptomatic, making regular ocular screening of such patients unnecessary.

Adolescent↗
PubMed1996

Acetazolamide and CO2: acute effects on cerebral and retrobulbar hemodynamics.

PURPOSE: Acetazolamide and CO2 are cerebral vasodilators whose specific effects in various brain regions have not been carefully defined. We investigated the effects of these agents in both larger cerebral and smaller, retrobulbar arteries, to compare their general cerebral vasodilatory influence with their specific ocular vascular effects. METHODS: Twelve young adults with healthy eyes were studied under normocapnic and hypercapnic (6% CO2, 94% O2 tanked gas) conditions after receiving either placebo or 1,000 mg acetazolamide (3 h before study). Color Doppler imaging was used to measure peak systolic and end-diastolic velocities (PSV and EDV) in the internal carotid, middle cerebral, ophthalmic, and central retinal arteries under each condition. RESULTS: Acetazolamide and CO2 each lowered intraocular pressure; combining the agents provided no additive ocular hypotensive effect. Hypercapnia or acetazolamide per se failed to alter PSV, EDV, or the derived resistance index [RI; (PSV-EDV)/PSV] in the internal carotid or in either orbital artery. However, when hypercapnia was superimposed upon acetazolamide, the resistance index fell in the internal carotid and central retinal arteries (each p < 0.05). In contrast, the middle cerebral artery was responsive to either vasodilator and to their combination: PSV and EDV rose, and RI fell with each experimental treatment. CONCLUSIONS: In the brain, the middle cerebral artery exhibits substantial dependence of flow velocity on the vasodilators CO2 and acetazolamide. In contrast, the ophthalmic and central retinal arteries appear less responsive. Nonetheless, the combination of carbonic anhydrase inhibition (acetazolamide) with CO2 augmentation did lower vascular resistance distal to the central retinal artery, suggesting that this mechanism vasodilates critical ocular tissues.

Acetazolamide↗