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Biomedical subjects

M M Rodrigues

Publications and source records attributed to M M Rodrigues.

At least 19 recordsLinked to original sources
PubMed1992

Ocular jellyfish stings.

BACKGROUND: Corneal stings from the sea nettle (Chrysaora quinquecirrha) indigenous to the Chesapeake Bay are usually painful but self-limited injuries, with resolution in 24 to 48 hours. METHODS: Five patients who developed unusually severe and prolonged iritis and intraocular pressure elevation after receiving corneal sea nettle stings were followed for 2 to 4 years. RESULTS: Decreased visual acuity, iritis, and increased intraocular pressure (32 to 48 mmHg) were noted in all cases. Iritis responded to topical corticosteroids and resolved within 8 weeks. Elevated intraocular pressure responded to topical beta blockers and oral carbonic anhydrase inhibitors. Mydriasis (4 of 5 cases), decreased accommodation (2 of 5 cases), peripheral anterior synechiae (2 of 5 cases), and iris transillumination defects (3 of 5 cases) also were noted. Mydriasis and decreased accommodation persisted for 5 months in 1 case and for more than 2 years in another. One patient has chronic unilateral glaucoma. Visual acuity returned to normal in all cases. CONCLUSIONS: The precise relationship between sea nettle venom and the observed clinical responses is not known. Corneal jellyfish stings usually produce a brief and self-limited reaction, but they do have the potential for long-term sequelae.

Adult↗
PubMed1992

Panstromal Schnyder's corneal dystrophy. Ultrastructural and histochemical studies.

BACKGROUND: A large cohort comprising four kindreds of patients with Schnyder's dystrophy has been identified in central Massachusetts. All patients were Swede-Finn with ancestry from the southwest Finnish coast on the Bay of Bothnia. METHODS: Of 60 members of this cohort examined by one of the authors (JSW), 18 had evidence of Schnyder's dystrophy. One female with Schnyder's dystrophy from each of three kindreds underwent penetrating keratoplasty for decreased visual acuity. We examined 4 corneal buttons from these unrelated women, aged 47, 63, and 72 years. RESULTS: The fluorescent probe filipin revealed that the majority of the lipid deposits were rich in unesterified cholesterol. Electron microscopy demonstrated abnormal accumulation of lipid and dissolved cholesterol in the epithelium, Bowman's layer, and throughout the stroma. Examination of the kindreds reflected the variable expression of crystals, which were present only in two patients, the 47-year-old and 63-year-old women. CONCLUSION: Ultrastructural and histochemical studies showed the panstromal localization of lipid in Schnyder's corneal dystrophy in three patients with Schnyder's dystrophy who underwent penetrating keratoplasty.

Aged↗
PubMed1992

Retinoblastoma: messenger RNA for interphotoreceptor retinoid binding protein.

Surgically excised retinoblastomas from 14 patients (age range nine months to two years) were assessed by immunocytochemistry for the expression of photoreceptor-specific proteins and neuronal and glial cell markers. Adjacent tissues were examined for messenger RNA expression of interphotoreceptor retinoid-binding protein (IRBP) using Northern blots. For immunocytochemical stains (ABC method), monoclonal and polyclonal antibodies included S-Ag, rhodopsin, neuron specific enolase (NSE), glial fibrillary acidic protein (GFAP), IRBP, neural adhesion molecule (N-CAM), and rod and cone specific transducin (TR alpha and TC alpha). Histopathology revealed mostly poorly differentiated tumors with necrosis and lack of Flexner-Wintersteiner rosettes. Immunocytochemical staining showed focal IRBP expression in one of the tumors and S-antigen in two cases. Immunoreactivity with rhodopsin was negative. N-CAM, a neural adhesive protein which appears to be involved in the regulation of adhesive interaction during neuronal differentiation, was positive except in two cases. All tumors showed immunoreactivity with NSE, whereas GFAP staining was limited to the perivascular glial tissue confirming the essential neuronal nature of retinoblastoma cells. TC alpha was detected in all tumors and TR alpha in one case. Messenger RNA for IRBP was detected in tumors in which IRBP immunoreactivity could not be detected.

Antibodies, Monoclonal↗
PubMed1991

Eye pathology associated with measles encephalitis in hamsters.

Measles encephalitis was produced in 41 hamsters by intracerebral injection of the hamster-neuroadapted Mantooth HBS viral strain. Group I (n = 10) included 2-day old (newborn) hamsters, each inoculated with 0.02 ml of 1:20 diluted virus. This group was sacrificed 4 days postinoculation (DPI). Group II (n = 31) included 25-day old hamsters, each inoculated with 0.03 ml of 1:10 diluted virus. This group was sacrificed 6, 13, 17, and 31 DPI. Clinical and histological evidence of measles encephalitis was present in all infected hamsters. Retinal lesions varied with the age of the animals at the time of inoculation. Retinal folds were observed in the 2-day old group and represented one form of retinal dysplasia. In the 25-day old group, however, earliest retinal involvement was in the form of hemorrhages, followed by focal retinitis in animals sacrificed 6-17 DPI. Measles keratitis was noted only in animals sacrificed 6 DPI. In 25-day old hamsters, measles keratitis and retinal hemorrhages represented the acute manifestations, whereas retinitis occurred later. However, ocular involvement did not correlate with the degree of severity of measles encephalitis.

Animals↗
PubMed1991

Identification of epitopes within the circumsporozoite protein of Plasmodium vivax recognized by murine T lymphocytes.

The murine cellular immune response to the circumsporozoite (CS) protein of Plasmodium vivax was characterized using five synthetic peptides, some of which we identified as corresponding to T cell epitopes. The peptides P308-320, P344-355 and P353-364 were immunogenic, inducing a genetically restricted proliferative response, due to the activation of CD4+ T cells. The peptide P308-320 was recognized only by the lymphocytes of B10 (H-2b) mice. The other two peptides were recognized by primed lymphocytes of H-2a and H-2k mice. Of interest was the finding that one of these peptides, P353-364, induced a proliferative response of a large percentage of immune outbred Swiss mice. Our data provide evidence that, at least in mice, there is recognition of multiple T cell epitopes within the major surface antigen of P. vivax sporozoites.

Amino Acid Sequence↗
PubMed1991

CD8+ cytolytic T cell clones derived against the Plasmodium yoelii circumsporozoite protein protect against malaria.

Immunization of BALB/c mice with radiation-attenuated Plasmodium yoelii sporozoites induces cytotoxic T lymphocytes (CTL) specific for an epitope located within the amino acid sequence 277-288 of the P. yoelii circumsporozoite (CS) protein. Several CD8+ CTL clones were derived from the spleen cells of sporozoite-immunized mice, all displaying an apparently identical epitope specificity. All the clones induced high levels of cytolysis in vitro upon exposure to peptide-incubated MHC-compatible target cells. The adoptive transfer of two of these clones conferred complete protection against sporozoite challenge to naive mice. This protection is species and stage specific. Using P. yoelii specific ribosomal RNA probes to monitor the in vivo effects of the CTL clones, we found that their target was the intrahepatocytic stage of the parasite. The protective clones completely inhibited the development of the liver stages of P. yoelii. Some CTL clones were only partially inhibitory in vivo, while others failed completely to alter liver stage development and to confer any detectable degree of protection. The elucidation of the effector mechanism of this CTL mediated protection against rodent malaria should facilitate the design of an effective malaria vaccine. From a broader perspective this model may provide further insight into the mechanism(s) of CTL mediated killing of intracellular non-viral pathogens in general.

Animals↗
PubMed1991

Interpositional polytetrafluoroethylene grafts. Conjunctival biocompatibility.

Polytetrafluoroethylene (PTFE) is a synthetic, woven, nonabsorbable, nonantigenic, Teflon-related material that has been shown to be useful in correcting eyelid retraction and as an implant enveloping material in primary and secondary surgery to correct anophthalmos. Implanted PTFE will extrude if not entirely covered with a layer of conjunctival epithelium. In vitro studies demonstrated that coating PTFE with collagen, fibronectin, gelatin, or laminin promotes epithelial cell and fibroblast migration over and adherence to PTFE. In vivo studies showed that a coating of type 1 collagen is most successful in preventing graft extrusion by promoting conjunctival epithelial attachment and growth over exposed PTFE. Further studies are needed to determine the optimum PTFE coating and pore size needed to ensure the consistent retention of uncovered implanted PTFE grafts.

Animals↗
PubMed1990

Cholesterol localization in ultrathin frozen sections in Schnyder's corneal crystalline dystrophy.

We examined a 57-year-old woman who had bilateral corneal crystalline deposits associated with xanthelasma. The patient's son had bilateral stromal haze. Plasma cholesterol and apolipoprotein A-I and B levels were normal. Histopathologic examination disclosed lipid deposits, particularly in the superficial stroma and Bowman's layer. These deposits stained with oil red O and filipin, a fluorescent probe that specifically detects unesterified cholesterol. Cryoultramicrotomy disclosed more specific ultrastructural localization of unesterified cholesterol with an array of crystals resembling multiple plates in extracellular corneal tissue.

Cataract↗
PubMed1990

Altered antigenicity of keratan sulfate proteoglycan in selected corneal diseases.

Monoclonal antibody against keratan sulfate (KS) was used for immunofluorescent staining of sections of human corneas from 8 normal eyes, 19 with keratoconus, 4 with pellucid marginal degeneration, 5 with primary macular corneal dystrophy, and 1 with recurrent macular corneal dystrophy. The anti-KS monoclonal antibody did not stain the corneas with primary macular corneal dystrophy, but stained all other corneas to varying degrees. Staining intensity was weaker than normal in most keratoconus and pellucid marginal degeneration corneas, and was very weak in a case of macular corneal dystrophy that had recurred in a transplanted normal cornea. In several corneas with keratoconus, normal staining was seen at the periphery, and staining intensity decreased in the thinned central portion of the stroma. The decreased KS staining was not localized in stromal scar tissue found in the keratoconus and pellucid marginal degeneration corneas. Quantitation of relative staining intensity found keratoconus and pellucid marginal degeneration corneas to be 49% and 40% as intensely stained, respectively, as normal corneas, a statistically significant decrease (P less than 0.01). Distribution of staining intensities of the keratoconus corneas demonstrated a single modality. These results are in agreement with findings of previous biochemical studies, which show reduction of highly sulfated keratan sulfate epitopes in corneas from keratoconus and pellucid marginal degeneration, and absence of sulfated keratan sulfate epitopes in macular corneal dystrophy.

Antibodies, Monoclonal↗
PubMed1990

Effects of epikeratoplasty on the host cornea. An experimental study.

The effects of epikeratoplasty on the host cornea was studied using albino rabbits. Eyes underwent midperipheral partial trephination alone (group I), midperipheral partial trephination and peripheral undermining (group II), midperipheral partial trephination and circular keratectomy (group III), and trephination, peripheral undermining, and circular keratectomy (group IV). Corneal topography was assessed weekly using keratometry and photokeratoscopy. All eyes showed central corneal steepening with enhancing effects of increased surgical manipulation. Results were stable by 4 weeks in all eyes. Histopathologic evaluation revealed a constant wound depth of approximately 0.1 mm, with an increased accumulation of glycosaminoglycan material at the base of the wound. This was stained with PAS and alcian blue. Steepening of the host cornea may be another reason for lack of predictability and refractive regression following epikeratoplasty.

Animals↗
PubMed1989

Polytetrafluoroethylene as an interpositional graft material for the correction of lower eyelid retraction.

Polytetrafluoroethylene (PTFE), a nonantigenic, autoclavable, inert, woven synthetic graft material was used to correct ten lower eyelids with retraction secondary to either thyroid disease (7 eyelids) or surgically repaired maxillofacial trauma (3 eyelids). The material was well tolerated for postoperative periods ranging from 10 to 26 months. In two eyelids, a portion of the PTFE was removed to treat eyelid thickening and an infected meibomian gland. Results of histopathologic examination of the graft showed minimal inflammation and capillary and connective ingrowth into the graft matrix as well as a dense fibrous capsule around the graft. In selected cases, PTFE may be an acceptable substitute for other graft materials used in oculoplastic surgery.

Adult↗
PubMed1988

Essential iris atrophy. A clinical, immunohistologic, and electron microscopic study in an enucleated eye.

A 29-year-old woman had unilateral essential iris atrophy, corneal endothelial changes, and absolute glaucoma. The enucleated eye was examined by routine light microscopy. Separate portions of unfixed fresh frozen cornea were sectioned and reacted with monoclonal antibodies against keratins, vimentin, and inflammatory cell markers. Stains for filamentous actin (f-actin) were performed using the 7-nitro-benz-2-oxa-1,3-diazolylphallacidin (NBD phallacidin) probe. In addition, portions of cornea and iris were examined by scanning and transmission electron microscopy. Immunocytochemical stains with anti-keratin antibodies showed reactivity only in the corneal epithelium of the patient and normal control. Immunoreactivity with anti-vimentin antibodies was observed in corneal endothelium and keratocytes of the patient and control, but was negative in the epithelium. Staining for f-actin appeared more pronounced in the corneal endothelium of the patient. Scanning electron microscopy of the corneal endothelium showed irregularity in cell size and shape and filopodial processes characteristic of migrating cells. Transmission electron microscopy disclosed abnormalities of Descemet's membrane and endothelium with a posterior collagenous layer. The corneal endothelium displayed normal junctional complexes without desmosomal junctions or increased microvillus projections. Increased 10-nm cytoplasmic filaments were noted consistent with the expression of vimentin. Occasional chronic inflammatory cells perturbed the corneal endothelium and were detected within the endothelial layer. Alterations in the endothelium and Descemet's membrane suggest the acquired nature of this disease.

Actins↗
PubMed1988

Trypanosoma cruzi metacyclic trypomastigotes: neutralization by the stage-specific monoclonal antibody 1G7 and immunogenicity of 90 kD surface antigen.

In this study we have investigated the ability of the stage-specific monoclonal antibody (MoAb) 1G7 to neutralize the infectivity of Trypanosoma cruzi metacyclic trypomastigotes (Tulahuen strain). Mice inoculated with metacyclics pre-incubated with 1G7 or the corresponding Fab fragments were found to develop greatly reduced parasitaemias compared with control animals. Similar results were obtained when mice received 1G7 (0.5 mg/mouse) before challenge with metacyclics. The 90 kD surface protein recognized by MoAb 1G7 was affinity purified and analysed for its immunogenic properties. Immunization of mice with 90 kD antigen induced antibodies that reacted with the native metacyclic surface antigen. The purified antigen was also capable of specifically stimulating the 'in-vitro' proliferation of 90 kD-primed T-cells. Furthermore, in a preliminary experiment in which mice were immunized with the purified polypeptide and challenged with Tulahuen metacyclics, low parasitaemia levels were observed in 60% of animals as opposed to non-immunized controls. The iodinated 90 kD antigen, which has previously been shown to be ubiquitous among T. cruzi strains, was precipitated by different immune sera including various chagasic sera.

Animals↗
PubMed1988

Novel 17-kilodalton Leishmania antigen revealed by immunochemical studies of a purified glycoprotein fraction recognized by murine T lymphocytes.

Recently, a glycoprotein fraction, designated gp10/20, purified from Leishmania mexicana amazonensis was shown to induce a cellular immune response mediated by murine L3T4+ T lymphocytes. This fact led us to pursue further the characterization of this fraction. The present study demonstrated that gp10/20 is a degradation product of a 17-kilodalton antigen present in promastigotes and amastigotes of L. mexicana amazonensis. This antigen was easily detected in promastigotes of L. mexicana mexicana, L. donovani, L. chagasi, L. major, and L. tropica. However, culture forms of L. braziliensis complex expressed either low amounts of the 17-kilodalton antigen or an antigenically unrelated antigen. The recognition of gp10/20 by several serum samples of patients with kala-azar was also shown.

Animals↗