Biomedical subjects
Publications and source records attributed to D M Albert.
Exposure of pregnant rats to inhalation of nickel carbonyl on days 7 or 8 of gestation frequently causes the progeny to develop ocular anomalies, including anophthalmia and microphthalmia. The incidence of extraocular anomalies is very low. The specificity of nickel carbonyl for induction of ocular anomalies in rats appears to be unique among known teratogenic agents.
A 66-year-old white woman with a confusing spectrum of central nervous system signs and symptoms had a diagnostic enucleation of her blind left eye showing retinal infiltration. Histopathologic examination showed reticulum cell sarcoma involving the retina. The patient died one month later and autopsy revealed diffuse central nervous system reticulum cell sarcoma along with right eye and systemic involvement. A review of the literature indicates intraocular reticulum cell sarcoma to be an apparently uncommon occurrence, although ocular examination may be frequently overlooked.
Fifteen owl monkeys (30 eyes) that received proton irradiation of discrete areas of the retina and choroid have been observed for 3 1/2 years or more after irradiation. The dose delivered to the retina varied from a single dose of 1,600 to 4,750 proton rads and from 10,250 to 18,250 rads delivered in five fractions over a period of one month. Fundus examination, fluorescein angiography, and light and electron microscopy revealed chorioretinal changes at the area of irradiation. The part of the retina adjacent to the chorioretinal scar showed preservation of normal retinal vascular architecture on trypsin digest studies of the retina and on electron microscopic examination, even 1 mm from the edge of the scar. The results of this study suggest that proton beam irradiation may markedly reduce delayed ocular complications, especially radiation retinopathy, which is common to other forms of radiotherapy in the treatment of intraocular tumors.
A 49-year-old man developed ataxia, myoclonic jerks, cortical blindness, and dementia. In 3 1/2 months, he rapidly deteriorated and died. Clinical and autopsy diagnosis confirmed Creutzfeldt-Jakob disease. The eyes were examined and bilateral optic atrophy was noted. No other ocular changes were noted. Optic atrophy had not been noted before death.
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The ocular histopathologic findings in three patients with the Stickler syndrome from two families included the following: total retinal detachment with marked folding, disorganization of the retina, and a preretinal membrane. The progression of the fundus lesions was followed up in two patients during the course of 30 and 24 years. Many cases variously reported as Wagner's disease, familial retinal detachment, hyaloideoretinopathy with cleft palate, and the Pierre Robin syndrome probably were the Stickler syndrome.
Three patients in three successive generations from the same family had choroidal malignant melanoma. The third generation patient had multiple primary malignancies; his siblings also had multiple malignancies. Chromosome studies of the third generation patient revealed no abnormality. To the best of our knowledge, this is the second such pedigree reported.
One hundred twelve patients with vitiligo were examined for ocular abnormalities. Discrete areas of depigmentation with associated pigment hyperplasia clinically appearing to involve the choroid and retinal pigment epithelium were observed in 44 patients, and active uveitis was seen in nine patients. The changes observed suggest that the spectrum of diseases that includes Harada's disease and the Vogt-Koyanagi syndrome may be broader than previously appreciated. Patients with these syndromes may represent the most severe examples of vitiligo and uveal inflammation. The occurrence of symptoms of night blindness in 12 patients and a family history of retinitis pigmentosa in two of these may signify a possible malfunction of the retinal pigment epithelium. Further evidence for a pigment epithelium disorder is suggested by the high incidence of an unusually prominent choroidal pattern in these patients.
Five patients seen in a one-year period with advanced malignant melanoma of the choroid in eyes with low visual acuity and clear media are reported. The low visual acuity appeared clinically to be antecedent to the malignant tumor; although in certain cases it may have been related to the occult melanoma, this was not appreciated clinically. Because of the low visual acuity, these patients did not have vision symptoms referable to the melanoma, and the malignancy was diagnosed late in its course. All five cases had extrascleral extension of the tumor at the time of surgical treatment; three are dead of metastatic disease, and two have undergone orbital exenteration with only brief follow-up periods. This experience suggests that eyes with clear media and low vision owing to presumably unrelated causes should undergo periodic examination to rule out the presence of a growing malignant melanoma and to prevent its late diagnosis.
New clinical and pathologic findings in patients with deletion of the long arm of chromosome 13 (13q-) include optic nerve hypoplasia and retinal dysplasia. Fibroblasts derived from patients with a 13q- syndrome with and without retinoblastoma, as well as from familial and sporadic retinoblastoma, are a useful model for the study of genetic susceptibility to the development of spontaneous and radiation-induced cancers. Fibroblasts from patients with hereditary retinoblastoma appear more radiosensitive than fibroblasts from patients with sporadic retinoblastoma or normal control patients.
The continuous culture of a hamster melanoma cell line has led to the spontaneous appearance of a retrovirus (HaRV) with typical type-C characteristics. The virus differs from all other known hamster viruses in its ability to transform murine as well as rat and hamster cells with apparent one-hit kinetics. Guinea pig, human and feline cells were not transformed although reverse transcriptase activity was detected in the supernatant from infected human cells. HaRV-transformed hamster embryo cells produced solid tumours (all non-pigmented) in 4 out of 35 animals when injected into hamsters while HaRV-transformed murine cells produced no tumours in mice. Injection of HaRV alone in hamsters, mice and rabbits did not induce tumours. HaRV possesses a 70S RNA which dissociates to 35S in DMSO and has a reverse transcriptase which utilizes the 70S virus RNA as a template. The size, morphology and density (1.15 g/ml) are similar to other known type-C viruses. Polyacrylamide gel electrophoresis indicates the presence of polypeptides analogous to those found in other type-C viruses.
This report is concerned with the capacities of aciclovir to protect mice challenged intracerebrally with multiple lethal doses of type 1 herpes simplex virus and to control multiplication of this virus in the brain. With treatment initiated 12 h after inoculation and continued for 4 consecutive days, aciclovir administered subcutaneously in daily doses ranging from 40 to 100 mg/kg led to 21-day survival rates of from 33 to 73% and reduced virus titers by 1 to (1/2) x 4 logs on postchallenge day 8. The therapeutic accomplishments of the 100-mg/kg doses of aciclovir were comparable to those of 1,000-mg/kg doses of vidarabine (9-beta-d-arabinofuranosyladenine); however, as measured by impact on body weight, aciclovir was better tolerated than vidarabine at these similarly effective doses.
A 52-year-old man with mild diabetes and acute stem cell leukaemia developed an orbitofacial mucormycosis. Cultures showed the fungus to be Rhizopus oryzae. Vigorous treatment with amphotericin B and other bactericidal and bacteriostatic antibiotics for a concurrent sepsis failed to suppress the infections, and the patient died. On post-mortem examination characteristic haematoxylin-staining, broad, aseptate fungal hyphae were found in the right eye, orbit, and lung. A striking and unusual feature of this case is the presence of brightly birefringent crystals within the severely degenerated eye. These were found by histochemical staining and x-ray diffraction studies to be calcium salts of fatty acids, apparently liberated from necrotic adipose tissue of the orbit.
This case report suggests that calcifications in the sclera and choroid may be a feature of pseudohypoparathyroidism and shows a calcium distribution more extensive and severe than that characteristically seen in other metabolic conditions associated with calcium deposits in the eye. Ocular ectopic calcification is a part of the more generalised ectopic soft tissue calcification seen with pseudohypoparathyroidism. Evaluation of the contribution of the terminal renal failure and uraemia to the ectopic ocular calcification would require sequential evaluation of eyes with pseudohypoparathyroidism, but without the added complication of uraemia.
The occurrence of vascular basophilia in ocular tumors has been a selective histologic feature of retinoblastomas. We recently observed a metastatic oat-cell carcinoma to the choroid which also demonstrated such a vascular hematoxyphilia. Histologic review of a variety of ocular and orbital metastatic carcinomas failed to yield a similar basophilic pattern. Examination of 100 consecutive retinoblastomas for vascular basophilia revealed an incidence of 6.0%. Similar material was not seen in any of 125 melanomas, including 10 with areas of necrosis. Histochemical studies showed the basophilic material to be DNA, and electron microscopy revealed the nuclear debris of pyknotic tumor cells to be continuous with identical material surrounding the adjacent blood vessels. The pathogenesis of vascular deposition of DNA in these two ocular tumors remains unclear. This finding most likely represents a form of tumor activity requiring comparatively healthy blood vessels to adequately precipitate liberated nucleic acids being filtered from the necrotic and degenerating tumor tissue.
According to recent theory on the structure of melanin, the sulfur content of melanin is a reflection of the amount of cysteine used in its manufacture. We compared the sulfur contents of melanins from hair, choroid, iris, and retinal pigment epithelium from black-haired cattle and separately from red-haired cattle. In black-haired cattle, sulfur contents of hair and ocular melanins were all between 0.60% and 0.94%, however, in red-haired cattle, hair melanin had a sulfur content (8.66%) different from those of choroid (0.94%) or RPE (1.72%) MELANIN. One may conclude that in an individual animal, ocular melanins can have different chemical structures from hair melanins. The clinical importance of this finding is discussed with regard to sympathetic ophthalmia.
Sequential histopathological observations were made of the rabbit corneas after an implantation of viable and nonviable tumor cells in the corneal stroma. They showed a nonspecific localized interstitial keratitis accompanied by inflammatory cells and new capillaries. We could not observe any significant clinical or histopathological differences between the corneas containing live or dead tumor implants, or between those with different tumor types (i.e., retinoblastoma and melanoma). Some variation in the severity of the inflammatory response was observed in different animals with the same tumor. In all cases, the extent of the corneal neovascularization correlated with the degree of inflammation. However, in rabbits made immune-deficient by radiation, there was negligible inflammation and vascularization when tumor was implanted.
Sustained release of 1,3-bis(2)chloroethyl)-1-nitrosourea (BCNU) via an episcleral implanted silicone device was used to treat Brown-Pearce epithelioma in the anterior chamber of rabbit eyes. One group of test eyes received BCNU dissolved in sesame oil; a second group received BCNU in pure ethanol. Control eyes received only the diluent, sesame oil or pure ethanol. The effectiveness of the various dosages and diluents was compared by clinical observation, by weight of the enucleated eyes, and by histopathologic examination. Sustained release of BCNU via an episcleral implanted silicone device delayed the growth of Brown-Pearce epithelioma in rabbit eyes of both test groups. The most effective action resulted from administration of BCNU in pure ethanol.