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Biomedical subjects

M M Rodrigues

Publications and source records attributed to M M Rodrigues.

At least 109 records · Page 6Linked to original sources
PubMed1985

Long-term effects of Q-switched ruby laser on monkey anterior chamber angle.

In an attempt to clarify whether pulsed lasers might be able to cause permanent fistulas from the anterior chamber to the interior of the canal of Schlemm, slightly suprathreshold, low energy, small diameter Q-switched ruby laser pulses were applied to the trabecular meshwork of nine eyes of six rhesus monkeys. Clinical examinations during the next 2 months disclosed no adverse effect on the cornea, iris, lens, or retina. There was transient mild inflammation in five eyes. Intraocular pressure was not changed significantly; the facility determined by perfusion of the anterior chambers at 2 months was normal. Light microscopy and scanning electron microscopy show localized trabecular lesions; some are slightly indented, but there is no persistent penetration to Schlemm's canal. Endothelial cells, confluent with those of the cornea, cover the inner (anterior chamber) surface of the lesions. Cross-sections through the center of a lesion show that trabecular meshwork and Schlemm's canal have been obliterated by the treatment and healing; these changes are similar to those previously seen after argon laser monkey trabecular treatment. In the untreated areas, between pulsed laser application sites, trabecular meshwork and Schlemm's canal are normal by light microscopic and scanning electron microscopic examination. Any effect on IOP from this particular type of pulsed laser treatment of the trabecular meshwork is probably not due to trabeculopuncture and flow of fluid through the fistula.

Animals↗
PubMed1984

Lack of evidence for protein AA reactivity in amyloid deposits of lattice corneal dystrophy and amyloid corneal degeneration.

Amyloid fibrils occurring in primary and myeloma-associated (AL), secondary (AA), and certain neuropathic hereditary forms of systemic amyloidosis can be distinguished biochemically or immunohistologically as being composed of immunoglobulin light chain, protein AA, or prealbumin respectively. All types of systemic and several localized forms of amyloidosis contain amyloid P component (protein AP). We studied formalin-fixed tissue from eight cases of lattice corneal dystrophy by the immunoperoxidase method using antisera to proteins AA and AP, to normal serum prealbumin and prealbumin isolated from a case of hereditary amyloidosis, and to light-chain determinants; additional cases were examined by indirect immunofluorescence of fresh-frozen material. We found weak (1:10 dilution) staining with anti-AP, but no reactivity with other antisera. Congo red staining was resistant to pretreatment of sections with potassium permanganate, a characteristic of non-AA amyloid. Two-dimensional gels of solubilized proteins from frozen tissue from two cases of lattice corneal dystrophy resembled those obtained from normal human cornea. Western blots of two cases of polymorphous amyloid degeneration and solubilized protein from normal cornea did not react with radioactive iodine-labeled anti-AA or anti-AP with purified protein AP and unfixed protein AA amyloid tissue as controls. We were unable to corroborate the presence of protein AA in the amyloid deposits of lattice corneal dystrophy. Although staining with antiserum to protein AP was demonstrable, the molecular configuration of this protein in stromal deposits remains to be defined.

Amyloid↗
PubMed1984

Color specular microscopy of disorders involving the corneal epithelium.

Color specular microscopy, a noninvasive, in vivo microscopic technique, was utilized to study the corneal epithelium in 17 patients including eight with keratoconus, seven with bullous keratopathy, and two with Fuchs' corneal dystrophy. Color specular microscopy was also performed on rabbit corneas with experimental surgical trauma. Changes observed by specular microscopy in these diseased states correlated with alterations noted by light microscopy and scanning and transmission electron microscopy. Specular microscopy can provide detailed in vivo cellular morphology of the ocular surface, obviating the need for tissue biopsy. Thus, specular microscopy is a valuable diagnostic technique available for the clinician to monitor changes of the diseased ocular surface.

Animals↗
PubMed1984

Ophthalmic involvement in acquired immunodeficiency syndrome.

Forty patients with acquired immunodeficiency syndrome (AIDS) were examined for ocular abnormalities. Twenty of these patients died and the eyes were obtained for culture and histopathologic examination. These patients have multiple opportunistic infections and neoplasms as the result of a severe depression of cellular immunity. Fifty percent of all patients with AIDS and 75% of the autopsy group have ocular signs attributable to AIDS. Ocular findings were confined to four major categories: cytomegalovirus retinitis (10 patients), retinal cotton wool spots (11 patients), conjunctival Kaposi's sarcoma (2 patients) and neuro-ophthalmic motility abnormalities (3 patients). Cytomegalovirus retinitis was a significant cause of visual loss. Seven of 40 autopsy eyes had hand motion or worse visual acuity prior to the patients' death because of CMV retinitis. This necrotic retinitis showed minimal inflammation and progressed to involve the entire retina in three to six months, resulting in a gliotic retinal membrane. Therapy with antiviral agents was not effective. Recognizing the ocular signs of AIDS may facilitate the diagnosis. The ophthalmologist also has a major role in the observation of progression or regression of these ocular manifestations, and can assist in the evaluation of therapy in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Keratophakia and keratomileusis: histopathologic, ultrastructural, and experimental studies.

We present ultrastructural findings in two cases, one of keratophakia (9 months postoperatively) and one of keratomileusis (1 year, 7 months post-operatively), which best demonstrate the pathologic changes we observed in six cases of cryorefractive surgery. In addition, we studied a rabbit model of keratophakia which appears to exhibit similar features to that of human keratophakia. In the keratomileusis cases, there were marked abnormalities, including deposition of redundant basal lamina, loss of Bowman's membrane and deposition of a 6 nm fibrillar material in areas devoid of Bowman's membrane. In keratophakia lenticule we noted the absence of keratocyte regeneration, abnormal deposition of long-spacing collagen, and the presence of necrotic cellular debris. In experimental keratophakia, little to no evidence of keratocyte regeneration was evident 4 months after surgery. Keratophakia lenticules implanted into actively regenerating corneas induced by freeze injury exhibit only a slight increase in the number of keratocytes migrating into the donor tissue, suggesting that implants lack a primary factor necessary for keratocyte regeneration. Immunofluorescent localization of fibronectin and fibrinogen demonstrated absence of these factors in normal host stroma, implanted lenticules and freeze injured corneal stroma. Actively migrating fibroblasts, however, did react positively for fibronectin, suggesting that these cells synthesize and secrete fibronectin during regeneration. These results do not support a role for soluble fibronectin or fibrinogen in keratocyte repopulation.

Adult↗
PubMed1984

Actin filament localization in normal and migrating rabbit corneal epithelium.

The molecular probe NBD phallacidin (7-nitro-benz-2-oxa-1, 3-diazolylphallacidin), which reacts specifically with filamentous actin (f-actin), was used to study the distribution of polymerized actin oligmers in normal and migrating rabbit corneal epithelial cells. In the normal cornea, the majority of the NBD phallacidin fluorescence was localized to the cortical or sub-plasma membrane area of the superficial and wing epithelial cells. Following full thickness corneal trephination injury, migrating corneal epithelial cell exhibited a marked increase in the cortical NBD phallacidin fluorescence. Transmission electron microscopy, using fixation techniques which revealed bundles of fine filaments (6nm underlying the plasma membrane of migrating epithelial cells, thus supporting the fluorescent results. These findings suggest that corneal re-epithelialization is characterized by a marked increase in the amount of filamentous actin within the migrating epithelial cells. We conclude that NBD phallacidin may be of value in analyzing changes in actin polymerization during wound healing.

Actins↗
PubMed1984

The pathology of pingueculae in Gaucher's disease.

Several reports have noted an apparent association between pingueculae and Gaucher's disease and suggested that the yellow coloring of these lesions is attributable to Gaucher cells. The authors biopsied pingueculae from ten patients with this disorder and examined them by serial light microscopy and electron microscopy. They failed to find Gaucher cells in any specimen, but, as typical for pingueculae, the elastosis observed histologically could account for their yellow hue.

Conjunctiva↗
PubMed1984

Choroideremia: a clinical, electron microscopic, and biochemical report.

An asymptomatic 19-year-old male with choroideremia had diffuse loss of retinal pigment epithelium (RPE) and choroid except for the periphery and macula. Fluorescein angiography of the arteriovenous phase showed absence of retinal pigment epithelium and exaggerated visualization of choroidal vessels in involved areas. The mother was a typical carrier with pigment stippling of the midperipheral retina. Histopathologic examination of affected areas of one eye showed marked degeneration of the outer and midretina with loss of retinal pigment epithelium and Bruch's membrane, absence of choriocapillaris, chorioretinal adhesions and gliosis. Atrophy of inner and mid-choroid was also observed. Pigmented macrophage-like cells had migrated into the outer and midretinal layers. Electron microscopy disclosed macrophage-like cells with trilaminar structures and photoreceptor phagosomes in the RPE and outer retina. Remnants of photoreceptor outer segments were adherent to the plasma membranes of the macrophage-like cells. Biochemical analysis of retinal tissue samples for interphotoreceptor retinoid-binding protein (IRBP) showed marked reduction in the 146K bands in the equator and posterior pole in the patient compared to controls. Cyclic nucleotide content was altered in the retinal equator. Cyclic AMP was several-fold higher in the RPE-choroid complex of the affected eye than in the control.

Adult↗
PubMed1984

Unilateral cytomegalovirus retinochoroiditis and bilateral cytoid bodies in a bisexual man with the acquired immunodeficiency syndrome.

A 42-year-old bisexual man with the acquired immunodeficiency syndrome, cryptococcal meningitis, disseminated Mycobacterium avium-intracellulare with mycobacteremia, and oropharyngeal candidiasis developed unilateral retinitis and bilateral cotton wool patches. Histopathologic examination revealed unilateral necrotizing retinochoroiditis with virions in retinal and choroidal tissues. Postmortem cultures of retina and choroid were positive for cytomegalovirus.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Abnormal corneal and eyelid development in the repeated epilation mouse.

Development of the eyelids and cornea in repeated epilation (Er/Er) mice is characterized by fusion of the tarsal conjunctiva to the epithelia of the bulbar conjunctiva and cornea. We investigated the ultrastructural features of this malformation and tested for abnormal expression of filaggrin by immunofluorescence. Heterozygous (Er/+) breeding stock were mated and 13,14,15, and 19-day-old embryos were studied by light and electron microscopy. Fusion occurred in all Er/Er specimens and was associated with abnormal migration of surface ectodermal cells onto the cornea. Immunofluorescence studies with antimouse filaggrin antibody on day 13 and day 15 revealed the presence of filaggrin precursors in the fused epithelia of mutants, but not in normal corneal or conjunctival epithelia. The results suggest defective regulation of the synthesis of cellular proteins and altered cell surface properties in the Er/Er ocular epithelia.

Abnormalities, Multiple↗
PubMed1984

Histopathologic verification of position of laser burns in argon laser trabeculoplasty.

Surgical trabeculectomy was performed on 10 eyes of 10 patients following failure of argon laser trabeculoplasty. All specimens were examined by scanning electron microscopy to determine anatomic location of laser damage. Correlation with clinical data revealed accurate placement of laser burns in 11 out of 13 treatment sessions. The degree of laser injury varied with energy delivered and pigmentation of the posterior trabecular meshwork. Complications such as corneal endothelial, oblique, and confluent burns were present in 50% of cases studied.

Argon↗
PubMed1984

Unusual superficial confluent form of granular corneal dystrophy.

A 53-year-old Japanese woman had corneal opacification due to granular dystrophy (GCD) since childhood. Clinically, unusual bilateral confluent dense granular opacities with a peripheral rim of clear cornea were observed. Her mother and daughter have a milder form of GCD, with circumscribed opacities separated by clear stroma. Light and electron microscopy of the patient's corneal button showed that the opacities involved the corneal epithelium as well as the stroma.

Corneal Dystrophies, Hereditary↗
PubMed1984

Acute intraocular pressure elevation after argon laser trabeculoplasty and iridectomy: a clinicopathologic study.

Trabeculectomy specimens excised from five patients with persistent, medically unresponsive elevation of pressure following argon laser trabeculoplasty and argon laser peripheral iridectomy were studied by light and electron microscopy. Histological examination disclosed macrophages, lymphocytes, activated trabecular endothelial cells, and tissue debris from trabecular beams. This inflammatory response and tissue debris initiated by laser treatment appears to be an important factor in the postoperative decompensation of the aqueous outflow system.

Acute Disease↗
PubMed1983

Corneal posterior crocodile shagreen and polymorphic amyloid degeneration.

Globes were obtained post mortem from a 75-year-old patient who had both corneal posterior crocodile shagreen and polymorphic amyloid degeneration. The crocodile shagreen was typified by grayish, polygonal opacities with indistinct edges and separated by clear lines. The cloudy area involved the central two thirds of the corneas and included the posterior two thirds of the stroma, with increasing posterior density. The polymorphic amyloid degeneration was typical, demonstrating polymorphic punctate and filamentous deposits in the deeper corneal layers. The deposits appeared white in direct illumination and refractile in indirect illumination. Transmission electron microscopy revealed sawtoothlike configurations of the stromal collagen lamellae that corresponded to the central cloudy opacities seen clinically. The minute deposits were found to be amyloid by histochemical staining and electron microscopy.

Aged↗
PubMed1983

Leishmaniasis affecting the eyelids.

Leishman-Donovan bodies were recognized in the smear of a biopsy specimen from an eyelid ulcer. The infecting organisms were identified serologically as Leishmania braziliensis panamensis. The ulcer responded to pentavalent antimony. Ultrastructurally, the organisms had double-unit membranes, beneath which lay a palisade of microtubules. At one end of the organism, there was a rudimentary flagellum; at the other, the nucleus. A kinetoplast basal complex separated the two.

Adult↗
PubMed1983

Microfibrillar protein and phospholipid in granular corneal dystrophy.

Keratoplasty specimens from eight patients with granular corneal dystrophy (GCD) and age-matched control subjects were examined by combinations of immunohistological stains, transmission electron microscopy (TEM), and sodium dodecyl sulfate gel electrophoresis. Fresh frozen sections from corneas with GCD stained positively with antibodies to microfibrillar protein by immunofluorescence. Routine TEM disclosed that the granules had central electron-dense areas partially surrounded by 9- to 10-nm tubular microfibrils. Material eluted from corneas with GCD showed denser peptide bands at 65 and 110 kilo than in normal corneas. Stains were negative for elastin, amyloid, neutral lipids, cholesterol, and glycosaminoglycan. Luxol fast blue MBSN stain was strongly positive in the granules in all cases examined. Immunofluorescent stains were negative with antibodies to plasma fibronectin (cold insoluble globulin), laminin, collagens I to V, basement membrane proteoglycan, tropoelastin, and keratin. In two corneas with GCD an increased lipid content was found in every phospholipid class, although cholesterol content was unchanged. Alterations in the fatty acid profiles of phospholipids were also observed.

Contractile Proteins↗
PubMed1983

The pathology of idiopathic midline destructive disease (IMDD) in the eyelid.

Subcutaneous eyelid and brow nodules were noted in a 25-year-old man who, at the age of 14 years, had developed the central facial and upper airway necrosis characteristic of idiopathic midline destructive disease (IMDD). One large nodule was located near the lateral canthus rather than a midline position. Insofar as we know, this report would constitute the first evidence of IMDD in the eyelids and brow in the absence of orbital disease.

Adult↗