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PubMed1999

[When parents decide against therapy for the children. The case of Emil M.: a conflict between parents and medicine].

If parents refuse to allow an accepted, scientifically well-founded treatment for their child, and if this results in obvious negative consequences for the child's welfare, the physician can appeal to the family court. Before doing so, however, a detailed explanation of the situation and counseling of the parents is imperative. In an emergency that brooks no delay, however, the physician can carried out the treatment he considers absolutely necessary even against the wishes of the child's parents. If, as a result of unacceptable parental decisions--e.g. withdrawal of treatment from the child--harm to the child ensues, the parents can hardly be pursued by the law, since, according to the principles of criminal law, this would only be possible if it can be proved without a shadow of doubt that the treatment would definitely have prolonged the child's life, or with certainty protected it from some other prejudice.

Germany↗
PubMedDate not supplied

[Genetic background of retinoblastoma].

Retinoblastoma is a malignant tumour of the eye ball, which develops as a result of the mutation of both alleles of RB-1 gene. Molecular mechanisms and their implications in clinical diagnosis and genetic counselling in retinoblastoma families are discussed.

Genetic Counseling↗
PubMed1998

[The structure, function and mutation of Rb gene promoter in normal individuals and retinoblastoma patients].

OBJECTIVE: To investigate the DNA sequence of the 5' untranslated region of the Rb gene in normal individuals and retinoblastoma patients and identify the elements involved in transcription regulation of Rb gene. METHODS: SSCP analysis and direct genomic DNA sequencing were used to identify variations or alterations in DNA of normal adult WBC and tumor DNA of retinoblastoma patients. The different DNA fragments located in the 5' untranslated region of Rb gene were amplified and inserted into an expression plasmid with a CAT reporter gene. The capacity of transcription regulation of isolated DNA fragments was determined by CAT assay. RESULTS: A 240 bp DNA fragment located between -327(-)-87 bp upstream of the first starting codon was shown to be the sequence with essential promoter function. The Sp1/RBF-1, ATF and E2F binding sites were present in this region and positive and negative elements were found further upstream and downstream. Four of 5 naturally occurring mutations were identified in either Sp1/RBF-1 or ATF binding sites from 302 patients with retinoblastoma. All these mutants had reduced CAT activity. However, 100 cases of normal adults did not show any variant DNA sequence in the same region. CONCLUSION: The promoter DNA sequence of Rb gene is quite stable. Its variation usually leads to reduction in promoter activity which may be associated with genetic susceptibility to retinoblastoma.

Adult↗
PubMed2000

[Retinoblastoma].

Hereditary retinoblastoma is different from non-hereditary retinoblastoma in the following ways. It has a germinal mutation of Rb gene located in 13q14. Its inheritance is autosomally dominant with 80% penetrance. Retinal tumors are present usually multiply (average number is three) in both eyes. The patients are found at a younger age than those non-hereditary retinoblastoma. About 5% of them are accompanied by a pineal tumor or paracellular neuroectodermal tumor, in such cases they are called trilateral retinoblastoma. Secondary malignancies such as osteosarcoma and rhabdomyosarcoma are more frequent, and they are the main causes of death of patients with hereditary retinoblastoma. Considering these facts, education of patients and their family members and development of new modalities of treatment for preserving eyeballs without inducing secondary malignancies are important.

Age Factors↗
PubMedDate not supplied

Transpupillary thermotherapy for retinal capillary hemangioma in von Hippel-Lindau disease.

Retinal capillary hemangiomas are a common manifestation of von Hippel-Lindau disease. We report the treatment of a peripapillary retinal capillary hemangioma in the left eye of a 30-year-old woman with this condition, using infrared diode laser transpupillary thermotherapy (TTT). The hemangioma was evaluated before and after treatment by ophthalmoscopy, fundus fluorescein angiography, and Doppler ultrasonography. Infrared diode laser TTT was delivered over 3 sessions during a period of 22 weeks, resulting in an improvement in visual acuity from counting fingers to 6/24 and a marked decrease in exudates surrounding the hemangioma. Doppler ultrasonography demonstrated a decrease in intralesional blood flow from 7 cm per second to less than 3 cm per second, together with a decrease in the size of the lesion. Infrared diode laser TTT provides a useful modality in the treatment of retinal capillary hemangiomas, and may be particularly favorable for peripapillary lesions because of its relatively nondestructive characteristics.

Adult↗
PubMed2000

Regulation of interphotoreceptor retinoid-binding protein (IRBP) gene expression by cAMP in differentiated retinoblastoma cells.

PURPOSE: To determine the mechanism of cyclic AMP (cAMP) regulation of the interphotoreceptor retinoid-binding protein (IRBP) gene in retinoblastoma cells. METHODS: WERI-Rb1 cells pretreated with laminin or grown on poly-D-lysine-coated substratum for three days were treated with forskolin/3-isobutyl-1-methylxanthin (IBMX) or with dimethyl sulfoxide (DMSO). During a time course of 96 h, cell morphologies were determined by light microscopy, cellular cAMP levels measured by radioimmunoassay, and IRBP and b-actin gene expression determined by Northern blot and RNase protection analyses. IRBP expression and b-actin gene expression in these cells were also determined in the presence or absence of actinomycin D or cycloheximide. RESULTS: After laminin treatment for 3 days, 27-34% of WERI-Rb1 cells differentiated into spindle shapes. Further forskolin treatment in the presence of IBMX for 5 days resulted in many cells exhibiting the formation of long, ramifying, neurite-like processes that were abolished by an inhibitor of protein kinase A. Cells grown on poly-D-lysine-coated substratum treated with forskolin remained undifferentiated. Treatment of laminin-pretreated cells with forskolin/IBMX, but not with DMSO/IBMX, raised the cAMP level 15-fold within the first hour of treatment. Northern blot analysis of these cells showed a rapid increase of IRBP mRNA, but not b-actin mRNA, reaching a maximum of about 3-fold at 6-8 h. A similar increase of IRBP mRNA was observed using RNase protection analysis except that the maximum was observed at 2-4 h. Actinomycin D blocked this IRBP mRNA induction. Cycloheximide had no effect in this induction. CONCLUSIONS: These results demonstrate that laminin induces WERI-Rb1 cell differentiation and cAMP provokes the formation of long ramifying neurite-like processes. Forskolin selectively induces IRBP gene expression in the laminin-treated cells through a cAMP-mediated pathway without de novo protein synthesis.

1-Methyl-3-isobutylxanthine↗
PubMed2000

[Vasoproliferative tumors of the ocular fundus].

PURPOSE: To establish the differential diagnosis from choroidal melanoma and other malignant tumors. METHODS: We report 5 patients with vasoproliferative tumors studied in our Hospital since 1993; diagnosis was mainly based on clinic appearance of the lesions. Each patient had undergone indirect ophthalmoscopy and ocular echography. RESULTS: Three upon five cases (studied before 1995) were treated with brachytherapy with Ir(192) because they were suspected to be choroidal melanomas. Periodical observation and treatment of associated complications was the treatment of choice in two other cases in which these complications determined the final visual acuity. CONCLUSION: It is important to establish the differential diagnosis between choroidal melanoma and other malignant tumors, as their prognosis and treatment are different.

Adult↗
PubMed2001

Management of retinoblastoma with radiation.

OBJECTIVE: To evaluate the role of radiation therapy in the management of retinoblastoma. DESIGN: Retrospective analysis. METHOD: From January 1993 to March 1994, one hundred and eleven children (150 eyes) of retinoblastoma were referred for radiotherapy. The diagnosis was based on clinical examination and ocular ultrasonogram for both the eyes. The radiation treatment policy involved 40 Gy in 20 fractions over 4 weeks delivered with sedation for children under 1 year of age, 36 Gy in 9 fractions over 3 weeks under ketamine anesthesia for 1-4 years of age and for >4 years of age, a dose of 50 Gy in 25 fractions over 5 weeks. The initial tumor regression was evaluated by A and B mode ultrasonography and/or CT scan. RESULTS: The age distribution ranged from two months to six years (median - 20 months). Bilaterality was observed in 39 out of 111 cases (35%). The male to female ratio was 1.8:1. Eighty two of the 111 children were treated by definitive external beam radiation to one or both eyes. Fifteen cases received adjuvant radiotherapy after enucleation, and 14 had extensive disease for which palliative radiotherapy was offered. We observed a complete response in 54% of cases, partial response in 32%, and none in 14% of cases. Forty per cent (40%) eye survival was documented at the end of 28 months. The complication rate encountered was about 15%. CONCLUSION: Radiotherapy is an effective modality of treatment in significant number of patients with retinoblastoma. However, it requires appropriate fractionation, precise colimation and careful immobilization with general anesthesia.

Child↗
PubMed2001

Solitary retinal capillary hemangioma: hereditary (von Hippel-Lindau disease) or nonhereditary?

OBJECTIVE: To estimate the probability of von Hippel-Lindau (VHL) disease in patients with solitary retinal capillary hemangioma. METHODS: Risk estimation was performed mathematically on the basis of the Bayes theorem using the published data on prevalence of VHL disease, prevalence of solitary retinal capillary hemangioma, and age-dependent penetrance of VHL disease. RESULTS: The probability of VHL disease in patients with solitary retinal capillary hemangioma was estimated to be 46%. When adjusted for age at the time of diagnosis, the risk varied from 45% in the young age group (</=10 years) to 0.5% in the older age group (61-70 years). CONCLUSIONS: Approximately half of the patients with solitary retinal capillary hemangioma are expected to have underlying VHL disease and the risk progressively diminishes with increasing age at diagnosis. Detailed clinical evaluation in such patients is recommended using standard screening protocols. Knowledge of the age-dependent risk for VHL disease can help the clinician modify recommendations regarding systemic and genetic testing.

Adolescent↗
PubMed2001

Adenoma of the retinal pigment epithelium simulating a juxtapapillary choroidal neovascular membrane.

We report a case of an adenoma of the retinal pigment epithelium that clinically simulated a juxtapapillary choroidal neovascular membrane in a 60-year-old man. Fluorescein angiography supported the diagnosis of a juxtapapillary choroidal neovascular membrane in his left eye. After 13 years the lesion become slightly pigmented and the optic disc became swollen. The possibility of choroidal melanoma with optic disc invasion was considered, and the eye was enucleated. The lesion proved histopathologically to be an adenoma of the retinal pigment epithelium.

Adenoma↗
PubMed1997

Electrophoretic determination of aqueous and serum neuron-specific enolase in the diagnosis of retinoblastoma.

PURPOSE: Neuron-specific enolase (NSE) of containing gamma-enolase is considered valuable in the diagnosis of tumours of neuroectodermal origin. METHOD: We used rapid electrophoretic method on cellulose acetate plate to determine the pattern of enolase isoenzymes in 21 aqueous humor and 23 serum specimens from retinoblastoma (Rb) and 21 aqueous and 25 serum specimens from 25 control cases to evaluate NSE in the diagnosis of Rb. The assay allowed assessment of all three major isoenzymes (alpha alpha, alpha gamma and gamma gamma), and NSE relative activity and its percentage in the total relative activity of the three enolase isoenzymes were assessed by means of fluorometer. RESULT: Aqueous from all patients with Rb contained alpha alpha, alpha gamma and gamma gamma isoenzymes and presented strong positive, the positive rate of NSE being 100% and its relative activity accounting for 45 +/- 9% of the total relative activity of the 3 enolase isoenzymes; No enolase was detectable in control aqueous with cataract, glaucoma and Coats's diseases (4 cases), but in two patients with traumatic hyphema alpha alpha and faint alpha gamma and gamma gamma were presented in aqueous. The control serum contained only an alpha alpha band, while the sera form patients with Rb contained alpha alpha, alpha gamma and gamma gamma bands in 18 of 23 specimens, the positive rate being 78.2%, and only alpha alpha bands in the rest 5 specimens (21.8%). In patients with Rb, the NSE relative activity and its percentage in the total relative activity of the 3 isoenzymes in serum (36 +/- 9%) were significantly lower lever than those in aqueous. CONCLUSION: The amounts of NSE increase significantly in both serum and aqueous from patients with Rb, and the immunoelectrophoretic assay for determination of enolase patterns is valuable in the diagnosis of Rb and differential diagnosis of Rb. In addition, the method is rapid, simple and requires only a little amount (< 5 microL) of samples.

Aqueous Humor↗
PubMed1997

Exon-by-exon screening for RB germline mutations using Heteroduplex-SSCP analysis.

OBJECTIVE: To disclose the nature of RB1 germline mutations in Chinese and to develop a practical and effective way for mutational screening. METHODS: Leukocyte DNA was prepared from 8 Chinese patients with hereditary retinoblastoma. PCR combined with nonisotopic heteroduplex-SSCP analysis was used to screen leukocyte DNA for RB1 germline mutations, exon-by-exon, without the use of restriction endonuclease digestion. The mutations were finally identified by sequencing. In order to testify the effectiveness of this method, the same method was used to detect other 17 samples which have been previously analyzed by other methods. RESULTS: Heterozygous germline mutations were detected in the leukocyte DNA of 6 out of 8 Chinese patients: G del/codon 46, T del/codon 131, CAGAA del/codon 257-258, GCAgta-->GCAgca/donor of exon 16, C-->T/codon 661, and C-->T/codon 787. Heteroduplex-SSCP analysis may detect RB1 germline mutations in 68% (17/25) unselected patients, which is more effective than SSCP(56%) or heteroduplex analysis(64%) alone. The corrected RB1 mutation detection rate may be 80% if the samples were previously analyzed by Southern blotting, which is much higher than those reported on literature. CONCLUSION: Mutations involving a few base pairs in RB1 gene are common in Chinese. Heteroduplex-SSCP analysis is more useful and effective than SSCP or heteroduplex analysis alone for the rapid screening for unknown mutations.

Female↗