Biomedical subjects
Publications and source records attributed to B L Johnson.
Pupillary membranes were experimentally produced in rabbits and correlated with biopsy specimens from human eyes which had undergone extracapsular cataract extraction. These fibrous membranes were derived from proliferation of lens epithelial cells. Wider anterior capsulectomies or barrier devices attached to intraocular lenses may reduce opacification of intact posterior capsules.
Biopsies were done for seven patients who had blinding optic nerve tumors or inflammations, using the fine needle aspiration technique guided by the CT scan. Cytologic material was recovered in this manner in all cases, which allowed the rendering of diagnoses. This allowed for therapeutic planning with minimal therapeutic invasion.
A 42-year-old woman had an orbital mass lesion removed surgically that proved histologically to be a spindle cell lipoma. To our knowledge, this is the first reported case of a spindle cell lipoma arising in the orbit. This specific type of lipoma occurs chiefly in male patients and is believed to affect the shoulder and posterior neck regions almost exclusively. Spindle cell lipomas, while having unusual features histologically, are benign and should not be mistaken for liposarcomas or other spindle cell soft-tissue tumors.
In 1966, Kenny described two patients with an unusual congenital syndrome including dwarfism, thickened long bone cortex, transient hypocalcemia, and normal intelligence. These and other patients previously were incorrectly described as "myopic". Ocular findings in four subjects ranged from uncomplicated nanophthalmos with hyperopia to extreme pseudopapilledema, vascular tortuosity, and mucular crowding. Postmortem findings from one patient showed calcium deposits demonstrable only by special histochemical stains that were distributed uniquely in the cornea. This distribution differed greatly from the pattern seen in band keratopathy. Retinal calcification was also an unusual feature. Because one patient exhibited a pseudodoubling of the optic papilla, the literature was reviewed. We conclude that no convincing case of true doubling of the optic nerve has been described. Ophthalmologists should be alert for undiagnosed electrolyte abnormalities, especially hypocalcemia, in patients with Kenney's syndrome.
Fifteen orbital tumors have been evaluated with the fine-needle aspiration biopsy (FNAB) technique. The best indication for FNAB is supposed malignant orbital disease. The technique has not been helpful in tumors or inflammatory disease with a high fibrous content. Lesions that are suspected of being pseudotumors are not recommended for FNAB since, even in histologic sections, they are notoriously difficult to distinguish from well-differentiated lymphocytic malignant lymphoma. Benign encapsulated tumors should not be subjected to FNAB.
Ten patients with biopsy-proved lymphoid hyperplasia (pseudotumor) of the orbit were treated with radiation therapy individed sose ranging from 2,500 to 3,000 rads. Five of the ten patients had prior treatment with corticosteroids in high dosages with only partial or no response. All ten patients had clinical resolution of the lymphoid hyperplasia orbital mass within three weeks following radiation therapy. A follow-up period of six months to five years has demonstrated no recurrences. There were no discernible complications from the radiation therapy. We believe that radiation therapy should be considered as a primary treatment of benign lymphoid hyperplasia of the orbit.
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Twenty-one patients with advanced ovarian cancer proven resistant to standard alkylating chemotherapy were evaluated in a prospective study of Hexamethylmelamine. All but three patients received 8 mg/kg daily with dose modifications appropriate to the degree of toxicity; the latter three patients were treated on an intermittent 14 day course of 8 mg/kg daily. Six patients (28%) experienced an objective response with a median duration of 2.5 months (range 1--5 months). The toxic effects requiring dose modification were gastrointestinal in 57%, hematologic in 62%, and neurologic in 28.5%. An average of 60.5% of the total projected dose was tolerated for a median of 44 days (range 7--113). Twelve patients (57%) experienced severe toxicity requiring discontinuation of therapy. It is apparent from this study that Hexamethylmelamine is an active agent in ovarian cancer and is not invariably cross-resistant to conventional alkylating agent therapy. These two characteristics make it an attractive agent for use in combination. Its toxicity in previously treated patients in the schedules used here, however, is substantial.
A 63-year-old man and his 24-year-old son developed recurrences of granular dystrophy in their three corneal grafts within three years after surgery. We regrafted one of the son's corneas. Histologic examination of the corneal button removed during surgery showed an avascular connective tissue layer with the histochemical characteristics of granular dystrophy interposed between the epithelium and Bowman's layer. In the remaining two corneal grafts, we fixed the globe with corneal forceps and removed the opaque dystrophic layer by separating it from the cornea with a spatula. Postoperatively, all three corneal grafts were once more transparent.
A 48-year-old woman with a primary intraorbital meningioma associated with the optic nerve sheath underwent a microsurgical removal of the tumor through a lateral orbitotomy. Visual recovery was essentially complete.
The neurotoxicity of methyl n-amyl ketone was investigated in a chronic inhalation study lasting 9 months. Rats and monkeys were exposed 6 hrs/day, 5 days/week, to mean MAK levels of 0, 131, and 1025 ppm. Electrodiagnostic measures of nervous system function revealed no neurotoxic impairment at either MAK exposure. Body weights were similarly unaffected. Gross and histopathology also indicated no adverse effects of MAK. It was concluded that MAK does not possess neurotoxic properties similar to those possessed by methyl n-butyl ketone.
Microscopic study of a keratoplasty specimen in a case of posterior polymorphous dystrophy demonstrated via serial sections a multilaminar Descemet's membrane with focal fusiform nodular protrusions of connective tissue. The latter are thought to represent the polymorphous lesions of the posterior limiting layers of the cornea seen clinically. Ultrastructurally, fibroflast-like cells lined the posterior surface of the cornea. It is postulated that those reported cases of PPD in which epithelial-like transformation of the endothelial layer has been described may represent more advanced cases, in which corneal oedema is likely to be a prominant feature clinically. An evolving process of metaplasia rather than a static one might explain the variety of altered endothelial cells, fibroblasts, and epithelial cells which have been reported on the posterior cornea in the few PPD keratoplasty specimens studied to date.
We have conducted a phase I clinical trial of maytansine, a plant alkaloid with potent tubulin-binding activity. For evaluation of toxicity, the schedule of drug administration consisted of a single iv infusion given every 3 weeks. Dose-limiting toxicity was observed at 2 mg/m2, and was manifested as profound weakness, diarrhea, nausea, and vomiting. Symptoms persisted for 3--14 days after drug administration. No consistent myelosuppression occurred at any dose level. Responses were observed in two patients (one each with non-Hodgkin's lymphoma and ovarian cancer) who were treated on the every-3-week schedule, as well as in two patients with acute lymphocytic leukemia treated with single weekly doses. Three of the four responding patients had received extensive prior treatment with vincristine, and two were clearly resistant to vincristine.
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Combination chemotherapy can dramatically improve the survival of those patients with advanced diffuse histiocytic lymphoma who enter complete remission. The age, sex, stage, constitutional symptoms, sites of disease and tumor mass of 56 consecutive patients with advanced diffuse histiocytic lymphoma were analyzed as prognostic factors. Twenty-four patients received cytoxan, vincristine, procarbazine and prednisone (C-MOPP) and 32 patients received bleomycin, adriamycin, cytoxan, vincristine and prednisone (BACOP). In 26 of 56 (46 per cent) a complete remission was achieved, in 21 of 56 (38 per cent) a partial remission and in nine of 56 (16 per cent) no response. Median survival with a complete remission was not reached at three years with 82 per cent still alive, but was significantly greater than with a partial remission (7.6 months median) or no response (3.2 months median). Survival of those with a partial remission and no response did not differ statistically. Stage IV disease, bone marrow involvement, gastrointestinal involvement and a tumor mass greater than 10 cm in diameter in a single location were all poor prognostic factors. No other analyzed factor significantly affected survival in this study. Complete response rates and survival curves for patients treated with C-MOPP were similar to those treated with BACOP.
A 48-year-old man who died of herpes simplex encephalitis had a bilateral papillitis at autopsy. Intranuclear inclusion bodies were especially numerous within the ganglion cells and inner nuclear layer of the macula and consisted of typical virions by electron microscopy. Contiguous spread from the brain to the eyes may have occurred via the optic nerves. Clinically, the disk and retinal changes were misinterpreted as being caused by papilledema. Papillitis should be included in the differential diagnosis of disk swelling in adults with suspected Herpesvirus hominis infection of the central nervous system.