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Biomedical subjects

M M Rodrigues

Publications and source records attributed to M M Rodrigues.

At least 163 records · Page 9Linked to original sources
PubMed1980

Corpora amylacea of the optic nerve and retina: a form of neuronal degeneration.

One hundred autopsy eyes were examined by light microscopy. Corpora amylacea (CA) occurred in 93% of the cases. Histochemical stains showed that these deposits are composed of sulfated polysaccharides. The fine structure of CA showed delicate, straight 6 to 7 nm thick filaments best demonstrated with the Thiery stain. In three cases, electron-dense vesicles resembling presynaptic vesicles were noted. These structures are characteristic of axons rather than of glial cells and could be related to protein synthesis. CA were present within myelinated and unmyelinated nerves and probably represent products of axonal degeneration.

Adolescent↗
PubMed1979

Posterior corneal crystalline deposits in benign monoclonal gammopathy: a clinicopathologic case report.

A 74-year-old woman had bilateral, deep stromal, patchy crystalline corneal deposits with the greatest density in the midperiphery. Visual acuity was 6/120 in the right eye and finger counting at 1 m in the left eye. Histological examination of the corneal button showed large, irregular amorphous masses in the posterior stroma. The deposits stained red with Masson's trichrome and were positive for protein with the Danielli stain. Stains for amyloid, copper, and lipid were negative. The immunoperoxidase stain was positive for polyvalent IgG and kappa light chains. Transmission electron microscopy disclosed electron-dense deposits with linear and honeycomb profiles. Laboratory investigations disclosed elevated serum and urinary IgG kappa light chain (Bence Jones protein) levels. Urinary amino acids were normal. The serum copper level was elevated. Antinuclear antibody was positive at a titer of 1:80. A bone marrow aspirate was normal, as were roentgenograms of the skull.

Aged↗
PubMed1978

Chandler's syndrome as a variant of essential iris atrophy. A clinicopathologic study.

Trabeculectomy and peripheral iridectomy specimens from one male and two female patients with Chandler's syndrome (age, 30 to 42 years) showed that all had unilateral corneal endothelial "dystrophy," corneal edema, mild to moderate iris atrophy without holes, peripheral anterior synechiae, and glaucoma. In one, fluorescein angiography of the iris disclosed a sector filling delay of limbal and conjunctival vessels and pupillary and extrapupillary leakage. Histopathologic examination showed a layer of degenerated corneal endothelium and Descemet's membrane extending across the inner uveal trabeculum. Descemet's membrane displayed irregular, nodular, scroll-like excrescences in some cases, and thinner placoid configurations with abnormal widely spaced collagen (100 nm) in others. Corneal endothelial cells exhibited increased microvilli, widened cellular interdigitations, and occasional shrunken cells with enlarged or disrupted cytoplasmic blebs. Peripheral iris specimens displayed mild to moderate stromal atrophy without vascular occlusions. Pigment epithelium was normal.

Adult↗
PubMed1978

Posterior keratoconus.

Posterior keratoconus is a rare corneal disorder characterized by a total or localized noninflammatory thinning of the cornea. In front of a conical protrusion of the posterior corneal curvature, there is a thinned stroma and nonprotruding anterior surface. A corneal button from a patient with bilateral posterior keratoconus was studied by light and electron microscopy. Descemet's membrane, particularly in the area of stromal thinning, demonstrated abnormal anterior banding, a multilaminar configuration, and localized posterior excrescences. These alterations suggest an early pathogenetic mechanism, which probably originated prior to the fifth or sixth month of gestation.

Adult↗
PubMed1978

Argon laser iridotomy on primary angle closure or pupillary block glaucoma.

Scanning and transmission electron microscopy were performed on peripheral iridectomy specimens from seven patients with failed pulsed argon laser iridotomies. Four to seven hours after the laser, severe edema, coagulation necrosis, focal vascular occlusion, and hemorrhage were present. Five days after the laser, cell detritus and collapsed cell processes were noted. Forty-two days after the laser, the anterior iris surface appeared considerably thinned and irregular. Eight and one-half months after the laser, the burn site displayed a dense matted appearance. Two years after the laser, the anterior iris showed a depression with pigment dispersion, irregular stroma, and disruption of the dilator muscle. The lack of inflammation could be due to the use of pulsed argon laser heat delivered at very short intervals, with deep penetration and minimal heat dispersion, since the beam is highly collimated.

Follow-Up Studies↗
PubMed1978

Argon laser iridotomy in the treatment of patients with primary angle-closure or pupillary block glaucoma: a clinicopathologic study.

A "pulsed" argon laser was successful in 48 of 64 (75%) attempted laser iridotomies. Scanning and transmission electron microscopy performed on specimens taken at varying intervals following laser treatment revealed progressive scarring of iris tissue. The complications appear minimal at this time, but longer follow-up is required before it can be stated that laser and surgical peripheral iridectomies are comparable. However, the laser's simplicity and ease of administration appear to warrant its continued use at this time.

Argon↗
PubMed1978

Congenital fibrosis of the extraocular muscles.

Congential fibrosis of the extraocular muscles is characterized by the replacement of normal contractile muscle tissue by fibrous tissue or fibrous bands in varying degrees. The clinical entities which result from the fibrous replacement can be classified under the following headings: general fibrosis syndrome, congenital fibrosis of the inferior rectus muscle with blepharoptosis, strabismus fixus, vertical retraction syndrome and congential unilateral fibrosis, enophthalmos and blepharoptosis. Genetic factors may or may not be apparent. One pedigree with general fibrosis syndrome was traced through five generations. Light and electron microscopy demonstrated replacement of normal muscle by collagen and dense fibrous tissue with occasional areas of degenerated skeletal muscle. The surgical mangement attempts to achieve some functional readjustment of the ocular and lid position as well as the abnormal head posture. The surgical results were considered satisfactory when compared with the original position of the eyes and the backward head tilt.

Adolescent↗
PubMed1977

Malignant fibrous histiocytoma of the orbit.

A 31-year-old woman had a mass in the posterior inferior orbit that progressively increased in size for almost two years. Histopathologic examination of an orbital biopsy specimen showed pleomorphic neoplastic cells arranged in a storiform pattern. The tumor cells were composed of hyperchromatic nuclei with prominent nucleoli and admixtures of fibroblasts. Electron microscopy demonstrated histiocyte-like cells with complex infoldings of plasma membrane, prominent mitochondria and golgi, and free ribosomes. Fibroblast-like cells displayed abundant rough endoplasmic reticulum and adjacent collagen fibrils. The diagnosis was malignant fibrous histiocytoma. An exenteration was performed and postoperative systemic chemotherapy with doxorubicin hydrochloride and methotrexate sodium sulfate was commenced. There was no evidence of recurrence two years later.

Adult↗
PubMed1977

Corneal opacification occurring after phacoemulsification and phacofragmentation.

Four patients developed progressive corneal opacification five to eight months after ultrasonic cataract extraction. Transmission electron microscopy was performed in all patients. Scanning electron microscopy, performed in only one patient, showed radiating folds of Descemet's membrane with pits on its posterior surface as well as focal traumatic disruption probably caused by probe contact. Bullous keratopathy was present in one patient. Two other patients had folds of Descemet's membrane and a thin retrocorneal fibrous layer. All four tumor specimens showed secondary epithelial and stromal changes. The common denominator was the total or partial absence of endothelium or marked alterations of its remnants.

Aged↗
PubMed1977

Demonstration of biogenic amines and adrenergic innervation in uveal malignant melanomas by the histoflurometric method.

Clinical and histologic studies were performed on 25 patients with malignant melanomas of the ciliary body and choroid. Portions of fresh tumor were quick frozen and processed by the histofluorometric technique to demonstrate the presence of biogenic amines. Separate portions of each tumor were fixed and processed for routine light microscopy. Specific fluorescence was visible in 21 of 23 pigmented neoplasms. Catecholamine-induced fluorescence of biogenic amines was related to tumor cell type. In two amelanotic tumors no specific fluorescence was seen.

Adult↗
PubMed1977

Staphyloma as a late complication of trabeculectomy.

A clinicopathologic study was performed of a scleral staphyloma occurring two years after a trabeculectomy for neovascular glaucoma. In a series of thirteen cases with secondary glaucoma four developed staphylomas in the area of the excision of sclera and trabeculum. A young, black male with atypical pigmentary glaucoma also developed a staphyloma. The possibility of the development of a staphyloma should be considered when selecting an appropriate operative procedure for uncontrolled glaucoma.

Adult↗
PubMed1976

Clinicopathologic correlation of microphthalmos with cyst.

Three patients had microphthalmos with cyst in one orbit and contralateral congenital cystic eye, microphthalmos alone, or microphthalmos with cyst. Four eyes were examined histopathologically. The microphthalmic eye demonstrated a spectrum of anterior segment abnormalities, retinal disorganization and gliosis, and a choroidal and scleral colomboma. The cyst connected to the colobona consisted of an outer fibrovascular layer and inner gliotic neuroectodermal layer. The cyst probably originated from proliferation of neuroectodermal tissue at the edge of a persistently open embryonic fissure. Treatment consisted of multiple aspirations of the cyst, excision of the cyst alone, and excision of both the microphthalmic eye and cyst.

Abnormalities, Multiple↗
PubMed1976

Spheno-orbital meningioma with optociliary veins.

A 40-year-old white woman had slowly progressive unilateral loss of visual acuity and increasing proptosis during an eight-year period. Ophthalmoscopy and fluorescein angiography revealed chronic disk edema and optociliary shunt vessels in the right eye. Polytomography showed an enlarged right optic canal. Cerebral arteriography demonstrated a dumbbell-shaped tumor blush in the right juxtasellar region and a diffuse tumor blush in the right orbit. Right frontal craniotomy and orbital exploration showed a cranio-orbital junction (spheno-orbital) meningioma that invaded the sclera and peripapillary choroid. Anomalous optociliary veins were demonstrated histologically at the optic disk.

Adult↗
PubMed1976

Alterations of Descemet's membrane in interstitial keratitis.

Twenty corneas from patients with interstitial keratitis were examined by light microscopy and one of these by electron microscopy. Seventy percent of patients had either a positive serologic test for syphilis or a history of treatment for syphilis. Focal or diffuse multilaminar thickening of Descemet's membrane with secondary linear guttata was present in 88% of cases. Confluent linear cornea guttata formed retrocorneal hyaline ridges that clinically showed a central gray core surrounded by a translucent sheath. Microscopically, these ridges consisted of concentric laminations of newly formed Descemet's membrane. Some ridges hung into the anterior chamber as a bow-like strand or a spiderweb network. A possible pathogenetic sequence may include (1) inflammatory insult to a relatively young endothelium; (2) alteration of endothelial function to fibroblast-like activity; (3) the production of abnormal basement membrane and other collagenous material and formation of a new multilaminar Descemet's membrane; and (4) separation of some ridges from the multilaminar Descemet's membrane to hang into the anterior chamber as strands and networks.

Anterior Chamber↗
PubMed1976

Juvenile glaucoma associated with goniodysgenesis.

Clinicopathologic studies, including electron microscopy, of trabeculectomy and peripheral iridectomy specimens from three patients with "juvenile" glaucoma revealed varying forms of maldevlopment of the chamber angle in all cases. A 20-year-old white woman (Case 1) had associated iridogoniodysgenesis with a pseudopolycoria-like iris pattern. In a 39-year-old white woman (Case 2), goniodysgenesis was associated with degenerated cell remnants in the angle "cleavage" area. A 15-year-old mentally retarded white boy (Case 3) displayed features of juvenile pigmentary glaucoma with associated goniodysgenesis and megalocornea.

Adolescent↗