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Biomedical subjects

D H Abramson

Publications and source records attributed to D H Abramson.

At least 91 records · Page 5Linked to original sources
PubMed1989

The focal treatment of retinoblastoma with emphasis on xenon arc photocoagulation.

Two-hundred-seventy-eight retinoblastoma tumors in 169 patients were photocoagulated by one of two doctors with the xenon arc photocoagulator. More than 70% of tumors treated were cured by photocoagulation. The following features correlated with success: 1) size of the tumor, 2) location of the tumor and 3) elevation of the tumor. Seventy of 72 tumors (97%) up to 1 dd in size were cured while only 9 of 22 (41%) tumors larger than 5 dd were cured. The mean size of tumors cured was 2 dd, while the mean size of those that failed was 3.9 dd. Tumors located anterior to the equator were more often successfully treated (67/81 = 83%) than those posterior to the equator (44/74 = 60%). Tumors with the height equal to half the base were classified as 'low elevation', while those with heights larger than half the base diameter were classified as high elevation. Tumors with low elevation did significantly better (162/201 = 81%) than those with high elevation (33/76 = 43%). No correlation was found between success and the following features: age at diagnosis, sex, age at first photocoagulation, eye involved (right or left), time from radiation to first light coagulation, nasal versus temporal tumors or the clock hour of the tumor or category of tumor independent of size of location. Forty-four percent of tumors that failed photocoagulation went on to develop vitreous seeding and 55% required enucleation. Fifty percent of the eyes that were treated initially with photocoagulation went on to develop new tumor foci elsewhere in the eye. In all cases the new tumors appeared anterior to the equator. The children who developed additional tumors in the eye were younger (5.5 months) when photocoagulated than those who did not develop additional tumors (47.75 months). Photocoagulated retinoblastomas must be followed for at least three years before a cure is certain.

Eye Neoplasms↗
PubMed1989

Trace anesthetic gases during xenon arc photocoagulation for retinoblastoma.

In pediatric ocular examinations, administration of continuous-flow anesthetic gases containing nitrous oxide, halothane, and oxygen enables the physician to do safe, controlled, reproducible examinations. We did a study in which the levels of waste anesthetic gases were measured during xenon arc photocoagulation procedures used for retinoblastoma. Waste nitrous oxide and halothane gases measured during these procedures significantly exceeded the levels recommended by the National Institute of Safety and Health. These high levels are of particular importance because of the physician's proximity to the patient during the procedure. The high levels of waste gases may have immediate deleterious effects on the physician's functioning capacity and may also pose long-term health hazards for the physician and operating room personnel.

Air Pollutants, Occupational↗
PubMed1988

Histopathologic effects of ultrasonically induced hyperthermia in intraocular malignant melanoma.

Four cases of human intraocular malignant melanoma were treated with ultrasonically induced hyperthermia immediately before enucleation. Tumors were treated in two regimens: 30 minutes at 43 degrees to 45 degrees C and 5 minutes at greater than 50 degrees C. Temperatures were estimated from applied power levels, based on empirical data and mathematical models. Histopathologic changes observed in human tumors were compared with changes seen in malignant melanoma xenografts in athymic nude mice which were treated with ultrasonically induced hyperthermia for 30 minutes at 42 degrees to 46 degrees C. The effects of treatment were similar to changes seen in the animal model treated under analogous conditions: increased intercellular spacing, cytoplasmic vacuole formation, clumping of chromatin, breaks in cell membranes, and swelling and collapse of cells. Perivascular and peripheral zones sometimes showed decreased damage levels. The high temperature (greater than 50 degrees C) technique is presently being used as a means of "sterilizing" tumors before planned enucleation. The moderate temperature (43 degrees-45 degrees C) technique has been used in combination with radiotherapy to treat tumors when vision can be salvaged.

Animals↗
PubMed1988

Cobalt plaque versus enucleation for uveal melanoma: comparison of survival rates.

Two hundred and twenty-three patients treated by cobalt plaque for uveal melanoma were compared with 416 patients treated by enucleation for uveal melanoma in terms of patient survival. The median follow-up time for the patients treated by cobalt plaque was 4.3 years. Kaplan-Meier survival curves were calculated up to five years following treatment based on time to tumour-related deaths. Cox's proportional hazards multivariate analysis was performed to determine which variables were related to melanoma-related deaths while controlling for age, size, and location of the tumours. Statistically significant predictive factors were location of tumour and largest tumour dimension. There was not a statistically significant difference in survival between patients treated by cobalt plaque and those treated by enucleation.

Adolescent↗
PubMed1987

Retinoblastoma with anterior chamber extension.

Anterior chamber retinoblastoma is a rare clinical entity. The authors have reviewed the records of 1500 patients with retinoblastoma to determine the incidence and prognostic ramifications. Of 30 patients with anterior chamber involvement, 15 were noted on initial examination and 15 during observation after therapy. Despite aggressive multimodality treatment, total response was never achieved and all eyes were eventually lost. Results of pathologic examination showed ciliary body invasion, which was held accountable for the poor response to therapy. Anterior chamber retinoblastoma is a poor prognostic sign which cannot be controlled effectively with current techniques and should be considered an indication for enucleation without delay.

Child↗
PubMed1987

Intraocular and extraocular retinoblastoma.

Retinoblastoma, the most common primary ocular malignancy of childhood, is a tumor in which the pediatrician and pediatric oncologist can now play a much more significant role in therapy. Developments in molecular biology have now made carrier testing and prenatal diagnosis feasible. In the near future, these developments should greatly augment the pediatrician's and pediatric oncologist's ability to offer accurate and appropriate genetic counseling for affected families. A practical staging system for extraocular retinoblastoma together with stage-related effective chemotherapy and radiation therapy was presented in this chapter. These modalities now make possible long-term survival for the majority of the 1 out of 8 children with retinoblastoma who would otherwise die from metastatic disease. Finally, 40 per cent of all children with retinoblastoma (those with the germinal mutation) are at lifelong risk for second, nonocular malignancies. The recognition that more than half of these children will actually develop second tumors by the fourth decade of life makes vigilant follow-up care for these patients a necessity.

Bone Neoplasms↗
PubMed1986

Ultrasonic hyperthermia and radiation in the management of intraocular malignant melanoma.

Hyperthermia and radiation were used in combination to treat four patients with choroidal malignant melanoma. This technique uses ultrasonically induced hyperthermia synergistically with radiation to destroy tumor cells. The lower levels of radiation used should avoid the late vascular and inflammatory complications seen in conventional radiation therapy. Tumors were scanned by a computerized diagnostic ultrasound system before treatment and assigned an acoustic tissue type on the basis of a statistical comparison of their ultrasound backscatter spectrum with spectra of tumors of known pathologic status. During the follow-up period, the longest of which was 15 months, all tumors demonstrated regression patterns consistent with choroidal tumors of the same acoustic tissue types treated with conventional radiation therapy.

Aged↗
PubMed1986

Unilateral vs. bilateral retinoblastoma. Correlations between age at diagnosis and stage of ocular disease.

Retrospective analysis of 358 cases of retinoblastoma for correlation between age and intraocular stage at the time of diagnosis revealed: in both early and advanced stages of intraocular disease, bilateral retinoblastoma presents at an earlier age than does unilateral retinoblastoma; support for the Knudson "two-hit" hypothesis of retinoblastoma genetics, the existence of a positive family history for retinoblastoma does not guarantee an earlier age at diagnosis compared to sporadic disease; and for any age at diagnosis, unilateral or bilateral disease, Group V is the most common intraocular stage found.

Age Factors↗
PubMed1985

Magnetic resonance imaging in the evaluation of leukocoria.

Leukocoria is an important clinical sign in ophthalmology. Conditions producing this white pupillary reflex must be differentiated from retinoblastoma to insure appropriate and timely treatment. Auxiliary diagnostic testing has been helpful in securing a clinical diagnosis. A new diagnostic modality, magnetic resonance imaging, provides similar morphologic information with the additional potential for biochemical characterization. A series consisting of 14 patients presenting with leukocoria as a result of retinoblastoma and simulating conditions was examined. The magnetic resonance imaging findings are discussed.

Child↗
PubMed1985

Computed tomography of the nonrhegmatogenous retinal detachment in the pediatric patient.

Nonrhegmatogenous retinal detachments occur in the pediatric population secondary to other ocular disorders. The most important cause to identify is retinoblastoma. Computed tomography has proven to be the most reliable ancillary diagnostic test in this pediatric population. A series of eighty patients, presenting with nonrhegmatogenous retinal detachments, was examined. The role of computed tomography and characteristic clinical findings are discussed.

Child↗
PubMed1984

Metastatic patterns of retinoblastoma.

Of 23 cases of metastatic retinoblastoma treated between 1922 and 1979, seven had metastases limited to the cranial vault and 13 had cranial metastases plus distant metastases. Globe pathology showed invasion of the optic nerve and/or the choroid in all but two patients, but was not predictive of the metastatic pattern. Initial signs of metastases were neurologic impairment and an orbital or body mass; first symptoms were anorexia or weight loss, vomiting, and headache. Most cases occurred by 3 years of age. Death occurred within 5.8 months on the average, despite therapy. Useful tests for determining the extent of disease were bone marrow aspiration, lumbar puncture, skull films, EEG, and brain scan. Computed tomographic scans of the head, bone scans, bone marrow aspiration, automated blood chemistry analysis, and lumbar puncture with immediate ethyl alcohol processing should prove to be useful to detect metastatic disease.

Bone Neoplasms↗
PubMed1984

Retinal detachment in the morning glory anomaly.

The morning glory anomaly is a rare congenital clinical entity that results from abnormal optic nerve development. In our series of 30 patients, followed for a mean duration of 10.3 years, 11 developed associated retinal detachments. These detachments followed a variable clinical course, including spontaneous reattachment and even redetachment, and may result from an abnormal communication between the subarachnoid space of the optic nerve and the subretinal space, allowing cerebrospinal fluid to accumulate subretinally. The clinical findings (including ultrasonography, computed tomography, and electrophysiologic testing), natural history, complications, and therapeutic indications are discussed.

Adolescent↗
PubMed1984

Second nonocular tumors in retinoblastoma survivors. Are they radiation-induced?

A review of 693 patients with bilateral retinoblastoma and 18 patients with unilateral/germinal retinoblastoma was carried out to find the incidence, time, course and pattern of second nonocular tumors in retinoblastoma survivors. Of 688 patients who survived therapeutic radiation for retinoblastoma, 89 developed second tumors: 62 in the field of radiation and 27 out of the field. Of 23 patients who received no radiation, five developed second tumors: one in the field and four out of the field. The most common tumor found was a sarcoma both in and out of the field of radiation. The incidence of second tumors increases with time, although the mean latent period is 10.4 years. At 10 years, the incidence of second tumors is 20%, at 20 years, it is 50% and at 30 years, 90%. The incidence of tumors in patients treated without radiation and where tumors developed outside the field was 10% at 10 years, 30% at 20 years and 68% at 32 years. There was no relationship between incidence of tumors and dose of therapeutic radiation when analyzed with life tables. A second course of radiation therapy did not increase the incidence of second nonocular tumors.

Brain Neoplasms↗
PubMed1984

Cytogenetic analysis of retinoblastoma: evidence for multifocal origin and in vivo gene amplification.

Retinoblastoma (Rb) is an uncommon childhood tumor of the neural retina with a significant genetic component in its etiology. A small proportion of patients have a deletion in chromosome 13 encompassing band 13q14, an observation which permitted the assignment of the RB1 locus to this region. About 20% of Rb tumors exhibit microscopic deletions of band 13q14 or monosomy 13. Trisomy 1q and i(6p) have also been reported in a high percentage of tumors. We analyzed the chromosome complements from direct preparations of 10 Rb tumors derived from seven patients. Modal chromosome numbers ranged from 45 to 48, and occasional duplications of the genomes were noted. In general, the tumors were chromosomally stable, although karyotypic evolution and random chromosome loss were encountered. Consistent abnormalities included trisomy 1q, i(6p), 6q-, and del(13)(q12----14). One patient with bilateral Rb had three tumor clones (two in one eye and one in the other) with chromosome abnormalities unrelated in origin. A second patient with unilateral Rb had two tumor clones with chromosome abnormalities again unrelated in origin. These two patients provide some of the first cytogenetic evidence for the multifocal origin of primary Rb. In the untreated tumor of a third patient, a homogeneously staining region (HSR) was detected in 1p32, indicating gene amplication in vivo; previously, an HSR at this site has been reported in the established Rb cell line Y79.

Adolescent↗
PubMed1984

Bleomycin-induced chromosome breakage in G2 lymphocytes of retinoblastoma patients.

Retinoblastoma (Rb) cells may be more sensitive to X-irradiation than normal cells when assayed for clonogenic survival, suggesting that such sensitivity can be used as a trait for detecting RB1 gene carriers. We studied induction of chromosome damage in lymphocytes from patients with Rb by the radiomimetic antineoplastic antibiotic, bleomycin (BL). Lymphocytes were treated in G2 for 4 h at four concentrations of the drug (0.0, 0.3, 0.9, and 2.7 micrograms/ml), and chromosome damage was evaluated. No difference in levels of spontaneous or induced damage was detected among hereditary Rb, non-hereditary Rb, and normal lymphocytes. The role of X-ray treatment in the induction of second tumors in Rb patients is discussed.

Bleomycin↗