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Biomedical subjects

W Sekundo

Publications and source records attributed to W Sekundo.

At least 37 records · Page 2Linked to original sources
PubMed1998

Primary conjunctival rhabdomyosarcoma: 2.5 years' follow-up after combined chemotherapy and brachytherapy.

BACKGROUND: The 2.5-year outcome of a 3-year-old girl with a primary intraconjunctival rhabdomyosarcoma treated by biopsy-controlled combined chemo- and brachytherapy is reported. METHODS: The patient presented with a conjunctival dermoid-like lesion which showed modest growth on 1-month follow-up. The first biopsy appointment was missed because of a viral illness. When she showed up 3 months later a further increase in size was obvious and several incisional biopsies were taken immediately. RESULTS: Light microscopy revealed an undifferentiated subepithelial small cell tumour. On immunohistochemistry the tumour reacted with vimentin and desmin antibodies. Thus, the diagnosis of an embryonal rhabdomyosarcoma was made. The patient underwent 9 cycles of polychemotherapy and the tumour mass disappeared macroscopically. However, immunohistochemistry of incisional biopsies showed residual tumour cells. The latter were eradicated by an individually shaped strontium-90 applicator. CONCLUSION: At 2.5 years after biopsy-controlled combined chemotherapy and brachytherapy the patient is free of tumour at a manageable level of complications. This new approach appears to be a good alternative in the treatment of primary conjunctival rhabdomyosarcomas since it takes advantage of the unique location of this rare tumour and avoids hemifacial retardation, known to be induced by external beam radiation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Hydroxyapatite orbital implant. A light- and electron-microscopic and immunohistochemical study.

OBJECTIVE: This study aimed to characterize the constituents of the ingrown host tissue in explanted orbital coral spheres by means of light electron microscopy and immunohistochemistry and to compare findings at different intervals after implantation. DESIGN AND METHODS: A microscopic retrospective laboratory study of three explanted coral spheres from three different patients was undertaken. The first specimen was an infected hydroxyapatite orbital implant, which was removed after 18.5 months and processed for standard light microscopy and transmission electron microscopy. Immunohistochemistry was performed using vimentin, actin, CD-68, and CD-34 marker. Two other explanted spheres (after 3 weeks and 2.5 months) were examined by light microscopy only, because no fibrovascular ingrowth could be detected. RESULTS: On light microscopy, the pores of the first coral were filled entirely with the fibrovascular tissue. A basophilic line reminiscent of calcium deposition was seen along hydroxyapatite spicules, where it often was associated with newly formed bony lamellae. Similar lines were seen partially in the 2.5-month specimen but not in the 3-week specimen. Immunohistochemistry of the first specimen enhanced visualization of the capillary network when the CD-34 marker was used. The fibrovascular tissue was uniformly vimentin-positive and partially actin-positive. On transmission electron microscopy, typical fibroblasts and myofibroblasts were observed. The latter were separated by thin sheets of banded collagen and formed pseudoepithelial structures. Proliferating vessels often showed high endothelial cells. CONCLUSIONS: The fibrovascular ingrowth contains not only vimentin-positive regular fibroblasts but also actin-positive myofibroblasts. Interaction between the invading tissue and hydroxyapatite structures leads to long-term ossification.

Actins↗
PubMed1998

Capillaries in the epithelium of pterygium.

AIM: To present new morphological observations of intraepithelial capillaries in pterygium and to provide some explanations for this phenomenon. METHODS: The ultrastructural features of pterygia from 26 patients were examined. Surgically excised tissue was processed for conventional light and transmission electron microscopy. RESULTS: Individual capillaries within the epithelium of the anterior half towards the head of pterygia were identified in 11 specimens out of 26 pterygia examined (42.3%). The perivascular connective tissue of the intraepithelial capillaries contained fibroblasts, collagen fibrils, and elastin-like material. Epithelial cells surrounding these capillaries showed defects in the basal lamina in contrast with the continuous basal lamina of the endothelium. In the intercellular space of the epithelium an amorphous substance, occasional fibroblast processes, and collagen fibrils were frequently observed. CONCLUSION: Capillaries in the epithelium of pterygia are rare, but not exceptional. The ingrowth of these vessels from the stroma into the epithelium can be interpreted as a reaction to hypoxia or deficiency of any other substance transported via the bloodstream. Apparently, the perivascular connective tissue can be used by ingrowing fibroblasts as a migration pathway. The migrating fibroblasts appear to use the defects of the epithelial basal lamina (whether partially or complete) in order to reach the intercellular space. It is possible that collagen fibrils in the epithelial intercellular space have been laid down by fibroblasts which contribute to the pathological dedifferentiation of the conjunctival epithelium.

Adult↗
PubMed1997

Immunomodulating activity of allopurinol in experimental lens-induced uveitis.

PURPOSE: The aim of this study was to evaluate the immunomodulating activity of allopurinol using a model of lens-induced uveitis (LIU) and to compare these effects to those of steroids. METHODS: We tested the sera of both LIU and control rats against western blots (WB) of SDS-PAGE separations of protein fractions from normal and LIU rat lenses. These blots were scanned using digital image analysis. A newly developed technique was used to compare the complex autoantibody (AAB) repertoires. Five groups of LIU rats were investigated: no treatment; single doses of methylprednisolone (MPR; 7.5 mg/kg body wt.i.v.); allopurinol (AL; 50 mg/kg body wt. i.v.); a combination of both drugs (AL and MPR); repeated application of AL (ALFR; 50 mg/kg body wt.i.v. every 2 weeks during the immunization period and a daily dose of approx. 25 mg/kg body wt. orally). RESULTS: Immunization induced complex antibody repertoires against lens proteins. Antibody repertoires of LIU rats were identical, regardless of whether the proteins were obtained from control, uveitis eyes, or corresponding healthy eyes of the same individual. AL showed a dose-dependent immunological effect in LIU treatment. Given as a single dose, AL revealed no significant change in the AAB repertoire; however, ALFR showed very clear modification of the AAB repertoires compared to both controls and rats receiving steroids. CONCLUSIONS: These results suggest dose-dependent effects of allopurinol in LIU treatment. Repeated application during the immunization period induced a strong immunomodulating effect of AL that was not observed after single doses.

Adjuvants, Immunologic↗
PubMed1997

Orbital tumour as a presenting symptom of breast carcinoma: value of detecting hormone receptors.

A 54-year-old woman was referred for evaluation of an orbital tumour after 5 months of non-specific ophthalmic symptoms. Tissue obtained by an open orbital biopsy was highly suspicious for asymptomatic metastatic breast carcinoma, which was discovered a few weeks later. Unlike the primary tumour, which was an invasive lobular breast carcinoma, the metastatic tissue was repeatedly negative for oestrogen and progesterone receptor markers. A possible reason is a change in cellular cytoplasmic and nuclear protein composition during the metastatic process. Since the primary tumour was positive for the hormone receptors, the patient was treated by chemotherapy and tamoxifen. The follow-up supports a favourable effect of adjuvant endocrinological therapy even in cases with receptor-negative metastatic tissue. This report is in partial contradiction to some previously published cases and emphasises the role of receptor status in the primary tumour.

Biomarkers, Tumor↗
PubMed1996

Hemangiopericytoma of the inner canthus.

PURPOSE: A 31-year-old woman with a mass at the left inner canthus was referred to our hospital. METHODS: Clinical examination failed to establish a diagnosis and the patient underwent an incisional biopsy. RESULTS: Histopathologic examination disclosed a hemangiopericytoma. CONCLUSIONS: Because the behavior of a hemangiopericytoma is unpredictable, this tumor should be included when making a differential diagnosis in lesions of the inner canthus.

Adult↗
PubMed1996

Effects of allopurinol and steroids on inflammation and oxidative tissue damage in experimental lens induced uveitis: a biochemical and morphological study.

AIMS: To evaluate the effects of allopurinol in lens induced uveitis (LIU) by morphological methods and to compare these effects with those of steroids and a combination of both drugs biochemically and morphologically. METHODS: Lipid peroxides (LPO) of the retinal tissue were determined by two different methods (thiobarbituric acid assay (TBA) and high performance liquid chromatography expressed as malondialdehyde-like substances). Myeloperoxidase (MPO) activity in the iris/ciliary body complex was analysed spectrophotometrically. Histological changes on three morphological levels of LIU eyes were evaluated. RESULTS: Both allopurinol and the combination of allopurinol/prednisolone led to a significant reduction in the increaed retinal LPO values. Prednisolone only revealed significant effects on retinal LPO when being measured with the TBA method. MPO activity in iris and ciliary body was significantly reduced in all therapy groups. The morphological evaluation of the sections by two masked investigators revealed a significant reduction (p < 0.05) in the inflammation score in all therapy groups. Morphometric studies using the QUANTIMED system (Leica, Cambridge) showed significantly reduced values (p < 0.05) in the allopurinol group and in the group receiving prednisolone and allopurinol. Prednisolone alone did not lead to a significant reduction in the values. CONCLUSIONS: The findings show that both allopurinol and steroids exert positive effects on the variables determined in LIU. The effects of steroids are believed to be mostly due to their direct action on inflammatory cells. The recently reported scavenging effects of methylprednisolone should play a minor role in this disease model. Allopurinol and oxypurinol act as direct scavengers of free radicals and hypochlorous acid, which is produced via MPO catalysis, thus leading to a reduction in tissue inflammation and tissue damage.

Allopurinol↗
PubMed1996

Monoclonal corneal gammopathy: topographic considerations.

Desposition of immunoglobulins in the cornea occasionally occurs in benign and malignant lymphoproliferative conditions. A 52-year-old woman with recently discovered monoclonal gammopathy of undetermined significance (MGUS) was referred to our hospital. Slit-lamp and ultrasound biomicroscopy revealed bilateral deposits within all corneal layers. The precipitates were organized in a circle, leaving a perilimbal zone and the axial cornea clear. Light microscopy of a biopsy disclosed confluent subepithelial deposits and defects in Bowman's layer. Immunoperoxidase reaction was positive only for IgG and IgG-kappa. Transmission electron microscopy confirmed the presence of extracellular rectangular and arcuate immunoglobulin crystalloids with a 10-nm periodicity but a non-crystalline defraction pattern. A review of the literature showed that the circumferential pattern of immunoglobulin deposition is associated with short-term visual symptoms and good visual acuity. The present report supports a hypothesis of immunoglobulin deposition via the limbal arcade and contradicts the "tear theory."

Biopsy↗
PubMed1995

[Traumatic wound dehiscence and corneal rupture 3 1/2 years after radial keratotomy].

BACKGROUND: Severe complications such as a traumatic wound dehiscence have been described very rarely after radial keratotomy. The following case demonstrates for the first time that wound healing is not completed even 31/2 years postoperatively and that therefore an ocular blunt trauma may still cause a dehiscence of the radial incisions. CASE REPORT: A 22-year-old patient presented in July 1993 to our emergency unit because of a corneal perforation in his right eye after a blunt trauma. His past medical history was significant for radial keratotomy surgery performed in January 1990 to correct a bilateral low-degree myopia (OD = -3.25 D; OS = -3.75 D). At surgery a horizontal rupture running through the entire cornea and including the two radial keratotomies at the 3 and 9 o'clock position was evident. The whole iris and lens were missing. The retina was completely detached. The corneal laceration was sutured. Twelve days later the retina was reattached with an encircling band, vitrectomy, endolaser and cryocoagulation, as well as silicone oil fill. Finally, a penetrating keratoplasty was performed 6 months after the accident. Thereafter, visual acuity improved to 0.1. The histologic examination of the corneal button showed that the wound healing of the incisions that had remained intact was not completed yet. Epithelial plugs of various size were still filling the somewhat dehiscent wound margins. Fibroblastic activity was detected in the surrounding stroma. CONCLUSION: Even several years after surgery, blunt traumas represent a definite risk for eyes undergoing radial keratotomy.

Adult↗
PubMed1994

Immuno-electron labelling of matrix components in congenital hereditary endothelial dystrophy.

Two corneal buttons were obtained from a patient with congenital hereditary endothelial dystrophy (CHED) at the ages of 2.5 years (right eye) and 14 years (left eye) and were studied by light and electron microscopy including immunogold labelling for collagen types I-V and laminin. The posterior collagenous layer (PCL) of Descemet's membrane contained collagen types I, III-V, and laminin: the latter was also localised to fine-banded and granular material in the posterior non-banded zone (PNBZ). Comparison of the endothelium 2.5 years and 14 years revealed occasional dystrophic changes in the former and extensive dystrophic changes in the latter. The distribution of collagen types I, III and V within the PCL supports previous morphological observations of fibroblast-like change of the endothelium in CHED. Persisting endothelial properties were manifest as positive labelling of type IV collagen and laminin. An excessive amount of laminin found in PNBZ and PCL is another stress-related endothelial reaction.

Adolescent↗
PubMed1994

An ultrastructural investigation of an early manifestation of the posterior polymorphous dystrophy of the cornea.

BACKGROUND: Posterior polymorphous dystrophy of the cornea is an uncommon, but well-recognized, congenital disease affecting Descemet's membrane and endothelium. Visual impairment usually is minimal and slowly progressive. Edema develops in a small number of patients, necessitating a corneal graft in middle age. An early manifestation of posterior polymorphous dystrophy with corneal edema present at birth or soon thereafter is extremely rare; only a few ultrastructural reports are available. METHODS: The corneal button of a 5-month-old baby with posterior polymorphous dystrophy was examined by conventional light and electron microscopy. FINDINGS: The anterior banded zone of Descemet's membrane was thinned (2 microns) in the axial part of the cornea, contained defects in the paraxial part, and was absent at the periphery. Where present, the anterior banded zone was lined posteriorly by a fibrocellular layer (containing fibroblast-like spindle cells and striated collagen fibrils) and a fibrillar layer forming an abnormal posterior collagenous layer. This layer was lined posteriorly by degenerate overlapping endothelial cells, which also were in apposition to the stroma in regions with an absent anterior banded zone. The defects in Descemet's membrane were used by the abnormal keratocytes to migrate between the anterior banded zone and the posterior collagenous layer. At the periphery, a multilayer of spindle cells was present behind the stroma. CONCLUSIONS: Failure to produce a continuous anterior banded zone indicates an onset of the disease before the twelfth week of gestation. It appears that, in posterior polymorphous dystrophy, there is a mosaic of better preserved and dystrophic endothelial cells and that the presence or absence of the normal components of Descemet's membrane is determined by the proportion of dystrophic cells in the endothelial cell population.

Consanguinity↗
PubMed1994

Bilateral uveal melanoma presenting simultaneously.

A case of bilateral uveal melanoma in a 54-year-old man is described. On admission of the patient for a choroidal melanoma of the left eye, an asymptomatic ciliary-body tumour was detected in his right eye. A thorough general examination did not reveal any metastases. The left eye was enucleated and local excision of the tumour in the right eye was performed 2 months later. Histology confirmed the presence of malignant melanomas in both eyes. The tumours were of similar A/B spindle-cell type. The patient remained healthy, showing no sign of metastasis or local recurrence of melanoma 9 months after the date of diagnosis. The visual acuity in his remaining eye remained 6/6. Immunological assessment of the blood serum revealed abnormally high interleukin 1 beta (IL-1 beta) and IL-2 levels. Possible implications of these findings are discussed.

Choroid Neoplasms↗
PubMed1994

Multirecurrence of corneal posterior polymorphous dystrophy. An ultrastructural study.

Posterior polymorphous corneal dystrophy (PPD) is a rare bilateral, autosomal-dominant disease. The presence of the epitheliumlike endothelium and the thickening of Descemet's membrane by the posterior collagenous layer (PCL) has been reported in the majority of published cases. Reepithelialization of the posterior cornea in donor tissue has been reported only once. Therefore, to examine this process we examined, by light and electron microscopy, three corneal buttons (an original and two subsequent keratoplasties after 3 and 4 years, respectively) from the left eye of a patient with bilateral disease. Our study showed a repopulation of the posterior surface of the donor corneas by the host epitheliumlike endothelium, which was of identical morphology in each case. In contrast to the previously published work, a posterior collagenous layer in the failed grafts was absent from the axial cornea, where the epitheliumlike endothelium was in direct contact with donor Descemet's membrane. A PCL at the periphery in the failed transplants was of the fibrocellular type and differed from the fibrillar PCL in the first keratoplasty specimen. The fibroblastlike cells within the fibrocellular PCL were distinct from the underlying epithelial-like cells and contained numerous tertiary phagolysosomes. We suggest that the major contributor to the fibrocellular PCL in the repeat keratoplasties was a fibrous ingrowth from the host/graft junction and not the epitheliumlike endothelium. It appears that the synthetic capacity of the epitheliumlike endothelium was similar to that of the normal epithelium and was much lower than that of normal native endothelium.

Corneal Dystrophies, Hereditary↗
PubMedDate not supplied

Differences in the composition of inflammatory cell infiltrate in lens-induced uveitis under therapy with allopurinol or steroids.

PURPOSE: The aim of this study was to compare the qualitative changes in the composition of inflammatory cell infiltrate in lens-induced uveitis (LIU) under treatment with allopurinol (Allo), methylprednisolone (Pred) or the two drugs combined (Allo/Pred). METHODS: Twenty male Wistar rats were sensitized with lens proteins for eight weeks. Intravenous (IV) therapy was started after anterior capsule disruption in one eye of each animal. Five rats were randomly assigned to each of the four groups: controls, Allo (50 mg/kg bw), Pred (7.5 mg/kg bw) and Allo/Pred (50 mg/7.5 mg per kg bw). Eyes were enucleated 24 hours later and fixed in paraformaldehyde/glutaraldehyde. Sections at three levels were stained with Giemsa and examined using a 0 to 4+ score for each type of inflammatory cell. Granulocytes were seen as neutrophils and eosinophils. Neutrophils were divided into polymorphs and "others", and graded with lymphocytes. RESULTS: In all therapy groups there was a significant reduction of polymorphs (p<0.05) in comparison to the control group. There was also a significant reduction in lymphocytes (p<0.05) in the Pred and Allo/Pred groups as compared to the control group and the Allo group. CONCLUSIONS: Single-dose IV allopurinol significantly reduced the overall number of polymorphonuclear leucocytes in LIU. Unlike methylprednisolone, allopurinol did not have any significant impact on lymphocytes.

Allopurinol↗
PubMedDate not supplied

Topical allopurinol or corticosteroids and acetylcysteine in the early treatment of experimental corneal alkali burns: a pilot study.

PURPOSE: To investigate the effect of topical allopurinol on experimental corneal burns and to compare this to established treatment modalities such as topical prednisolone and acetylcysteine. METHODS: Twenty Wistar rats were randomly assigned to four groups (n=5 each). The groups were controls (normal saline), allopurinol 0.4% eye drops, prednisolone acetate 1% eye drops and acetylcysteine 8% eyedrops. Corneal burn was induced using a 3 mm paper disc soaked in 1N NaOH for 60 seconds. Drops were instilled 6 times per day. In addition, one drop/day ofloxacine was given to prevent secondary infections. Eyes were enucleated 50 hours later and fixed in 4.5% formaldehyde. Three histological levels of each globe were stained with hematoxylin-eosin and examined by two independent masked investigators using a 0 to 4+ inflammatory score. All pair-wise multiple comparison procedures (Student-Newman-Keuls method) were applied for statistical work-up. RESULTS: All three substances significantly reduced the number of histologically visible inflammatory cells compared to the control group (p<0.05). CONCLUSIONS: In the present study, topical allopurinol was as effective as established drugs, namely steroids and acetylcysteine, in the early treatment of experimental alkali corneal burns.

Acetylcysteine↗
PubMedDate not supplied

Lidocaine-assisted xylocaine jelly anesthesia versus one quadrant sub-Tenon infiltration for self-sealing sclerocorneal incision routine phacoemulsification.

PURPOSE: To compare the effect of xylocaine jelly and intracameral lidocaine with one quadrant instant sub-Tenon infiltration for self-sealing sclerocorneal phacoemulsification. METHODS: One hundred patients were enrolled into a prospective randomized study, receiving either a combination of topical 2% xylocaine jelly and 0.5 ml of intracameral 1% lidocaine or sub-Tenon infiltration with 2 ml of 2% xylocaine on the operating table. All patients underwent a standard divide and conquer phacoemulsification procedure through a superior sclerocorneal frown incision followed by implantation of a polymethylmethacrylate intraocular lens. Intraoperative pain was indicated by the patient by squeezing the bedside nurse's hand, who allocated it to particular stages of surgery on a chart. After surgery, patients assessed the pain experienced using a 10-unit visual analogue scale. RESULTS: Pain was indicated on 31 occasions during the operation in the sub-Tenon group (mainly the injection itself) and 67 times in the topical group. The median overall subjective pain score was 3 in the jelly group and 0 in the sub-Tenon. Five eyes (10%) had to be converted to sub-Tenon during the surgery because of intolerable pain. CONCLUSIONS: Whereas lidocaine supported xylocaine jelly anesthesia provided acceptable analgesia for 90% of patients operated, sub-Tenon anesthesia proved to deliver better intraoperative comfort in all patients receiving sclerocorneal incision cataract surgery.

Aged↗