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Biomedical subjects

M A Simon

Publications and source records attributed to M A Simon.

At least 181 records · Page 10Linked to original sources
PubMed1977

Giant papillary conjunctivitis in contact lens wearers.

A syndrome that occurred in both hard and soft contact lens wearers was characterized by increased mucus, itching, decreased lens tolerance, and giant papillae in the upper tarsal conjunctiva. It developed in as few as three weeks with soft lens wearers but also occurred after months or even years of successful wear. The histology was characterized by basophils, eosinophils, and mast cells in the epithelium, and these cells as well as increased numbers of lymphocytes, plasma cells, and polymorphonuclear leukocytes in the stroma. The syndrome may be immunologic in origin with deposits on the lenses as the antigen, and the syndrome may be a major cause of difficulty in wearing contact lenses once they have been successfully fit.

Antigens↗
PubMed1977

Histamine in human tears.

Tear samples from 13 normal volunteers and nine patients with vernal conjunctivitis were assayed for histamine. Tears in both groups contained histamine. The normal subjects had values ranging from 2.2 to 36 ng/ml with a mean of 10.3 ng/ml. The vernal patients had histamine values ranging from 0 to 125 ng/ml with a mean of 3,.2 ng/ml. The presence of histamine in tears indicates a role for this important mediator in both the physiologic and immunologic processes of the external eye.

Conjunctivitis↗
PubMed1976

Plasma cell content of main and accessory lacrimal glands and conjunctiva.

The size, weight, and plasma cell content of main and accessory lacrimal glands were examined and compared to the number of plasma cells in the conjunctiva. There were from four to 35 accessory lacrimal glands in the upper conjunctiva and a rare accessory gland in the lower conjunctiva. The total accessory gland mass was approximately one tenth of the lacrimal gland mass although the number of plasma cells was approximately 1/20 of the mass. The number of plasma-cells in the lacrimal gland was estimated to be 3,200,000; in the conjunctiva, 2,100,000; and for the accessory glands, 180,000. Because of the many plasma cells in the relatively inaccessible lacrimal gland, cells of the lymphatic series may home to the lacrimal gland by non-antigenic mechanisms.

Adult↗
PubMed1976

Tissue, tear, and serum IgE concentrations in vernal conjunctivitis.

Abnormal upper tarsal tissue from four patients with vernal conjunctivitis stained immunofluorescently contained abundant IgA-, IgD-, and IgE-forming plasma cells in two of four patients. These were absent in normal upper tarsal conjunctiva. The IgE levels of paired tear-serum samples of 11 patients with vernal conjunctivitis and ten control subjects were 130 ng/ml in patients that did nor differ significantly from the normal tear IgE value of 61 ng/ml. The serum IgE means of 1,031 ng/ml for patients and 201 ng/ml for normal subjects differed significantly (P less than .05). Tear and serum IgE values correlated significantly for both groups (P less than .01 for patients, P less than .05 for normal subjects). These findings are consistent with a hyperplasia of IgA, IgD, and IgE antibody-forming cells in tarsal conjunctiva of some patients with vernal conjunctivitis, and tear IgE levels being a function of serum IgE levels.

Adolescent↗
PubMed1976

The management of soft-tissue sarcomas of the extremities.

Of fifty-four patients with a soft-tissue sarcoma of an extremity, having a projected five-year survival rate of 62 per cent, forty-six treated by an "adequate" surgical procedure (either radical local resection or ablation at an appropriate level, depending on defined circumstances) had a local recurrence rate of 2 per cent. In the other eight patients, whose surgical procedures were not adequate for one reason or another, the local recurrence rate was 100 per cent. The combined recurrence rate after both the adequate and the inadequate procedures was 16.7 per cent. The recurrences were noted prior to thirty months post-operatively and the metastases, prior to sixty months. Histogenesis of the sarcoma, one or more recurrences after previous operations, and treatment by an immediate definitive procedure at the time of biopsy and diagnosis by frozen section had no significant relationship to the rates of local recurrence or metastasis. Adequate radical local resection controlled these sarcomas as well as ablative surgery in terms of local recurrence and metastasis. The significant factors affecting local recurrence that were identified in this study were the location of the sarcoma and the adequacy of the surgical procedure.

Adolescent↗
PubMed1975

Segmental resection for chondrosarcoma.

Specific anatomical and pathological criteria for resectability of so-called central chondrosarcoma of the extremities were set forth and a method of treatment based on autoclaving the segment and surrounding it with massive amounts of fresh autogenous cancellous bone was used in eight patients. Follow-up ranged from 3.2 to 13.5 years. The advantages of the method are: ease of procurement of bone graft, absence of storage and measurement problems, and lack of need for rigid immobilization. No secondary procedures were required because of fracture, resorption, or infection.

Adult↗
PubMed1973

Elastofibroma.

Explore the source record for details and available documents.

Adult↗
PubMed1971

Mutant of Clostridium pasteurianum that does not fix nitrogen.

A stable, non-nitrogen-fixing mutant of Clostridium pasteurianum W5 was isolated. The mutant has the same growth rate as the wild type on ammonia nitrogen, but is not able to grow on N(2). Cell-free extracts of the derepressed mutant are unable to fix nitrogen, or reduce the alternate substrates of nitrogenase such as cyanide, azide, or acetylene. Recombination with wild-type components from a diethylaminoethyl cellulose column indicates that the mutant contains component II, but is lacking component I activity.

Acetylene↗