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Biomedical subjects

R Belfort

Publications and source records attributed to R Belfort.

At least 55 records · Page 3Linked to original sources
PubMed1991

Immunohistochemistry of the inflammatory response in Propionibacterium acnes endophthalmitis.

Specimens were obtained from two patients with culture-proven Propionibacterium acnes endophthalmitis who had undergone vitrectomy. Wright's and Giemsa stains were performed using cytospin preparations of the dilute vitreous and revealed a predominance of polymorphonuclear leukocytes (80% to 90%). The remaining inflammatory cells in the vitreous were mostly macrophages (10% to 15%); very few lymphocytes were present (less than 5%). Immunohistochemical studies using monoclonal antibodies confirmed the paucity of lymphocytes. Most lymphocytes were CD4+ helper/inducer T cells. Almost no CD8+ suppressor/cytotoxic T lymphocytes or B lymphocytes were found. The inflammatory response in these two patients is most characteristic of acute inflammation and consistent with an underlying bacterial infection, despite a clinical picture of persistent, low-grade inflammation. Infection with P acnes has been shown to inhibit CD8+ T cells and may play a role in the persistent inflammation in cases of P acnes endophthalmitis.

Aged↗
PubMed1991

Light and electron microscopic analysis of intraocular 2% hydroxypropylmethylcellulose.

Twenty samples of 2% hydroxypropylmethylcellulose for intraocular surgery, obtained from two Brazilian laboratories, were studied to determine the presence and type of impurities in the solutions. These were compared with ten samples of balanced salt solution (control group). Using light and scanning electron microscopy, five types of particles were identified: cellulose fibers, vegetable flakes, crystals, glass fragments, and other impurities. At least one of these contaminants was present in each sample of 2% hydroxypropylmethylcellulose. The vegetable matter was also seen in a sample of the raw material from which the clinical material had been prepared. Control solutions (i.e., balanced salt solution) were free of vegetable matter and of crystals, but glass fragments and other impurities were present. The average number of foreign particles in the solutions of hydroxypropylmethylcellulose (91.2 and 96.7 particles per milliliter for each of the two groups) was statistically greater than in the balanced salt solutions (13.7 particles per milliliter).

Drug Contamination↗
PubMed1991

Ocular complications of Stevens-Johnson syndrome and toxic epidermal necrolysis in patients with AIDS.

Recent reports suggest that acquired immunodeficiency syndrome (AIDS) patients are at higher risk of developing mucocutaneous reactions such as toxic epidermal necrolysis and Stevens-Johnson syndrome (SJS). Resultant dry eye may be further exacerbated by human immunodeficiency virus (HIV) related lacrimal gland dysfunction and lead to a chronic keratoconjunctivitis. We report one patient with AIDS and toxic epidermal necrolysis and two patients with AIDS and SJS who developed severe dry eye misdiagnosed as infectious keratoconjunctivitis. Cicatrizing mucocutaneous reactions should be suspected in AIDS patients and the dry eye treated to control symptoms and prevent complications.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Central and peripheral corneal thickness in newborns.

Central and peripheral corneal thickness was measured in 74 newborn children. The mean central corneal thickness was 0.573 +/- 0.052 mm. The mean peripheral thickness was 0.650 +/- 0.062 mm. There was no significant difference between right and left eyes, sex, gestational age or type of delivery. The central and peripheral corneal thickness in the first 24 h of life was significantly higher than after 48 to 72 h. The full-term babies with 2.500 to 3.000 g of birth weight had peripheral corneal thickness higher than the group with 3.501 to 4.000 g.

Birth Weight↗
PubMed1990

Identification of Toxoplasma gondii in paraffin-embedded sections by the polymerase chain reaction.

We used the polymerase chain reaction to amplify DNA fragments specific to Toxoplasma gondii. The sensitivity of the technique allowed for the detection of as few as ten cultured T. gondii tachyzoites. We applied the same amplification technique to deparaffinized ocular sections from two cases of ocular toxoplasmosis. Although toxoplasmic cysts could only be seen in one eye by optical microscopy, polymerase chain reaction allowed the identification of the parasite in both cases. Our study indicates the feasibility of a sensitive DNA-based assay to complement pathologic studies of an ocular parasitic disease.

Adult↗
PubMed1988

Epidemiological study of eye injuries in Brazilian children.

A year-long follow-up study of 146 eye injuries in children up to 15 years of age was carried out in two emergency hospitals of a southern Brazilian city. These injuries represent approximately 65% of the total number of patients seeking ophthalmic care at emergency hospitals within this city. Patients were followed up for at least four months after injury; visual results as well as epidemiological factors were analyzed. Based on these findings, children in the 0- to 5-year-old group were at greatest risk, regardless of sex; among children older than 5 years, eye injuries were more frequent in boys. Generally, the child takes part in the accident as an active participant, and adequate adult supervision decreases the number of these accidents. Analysis of the relationship between socioeconomic levels of the parents and severity of eye injuries revealed that severe eye injuries were more frequent in lower socioeconomic strata. In severe eye injuries 35.1% of the children ended with visual acuity under 20/200 in the affected eye, which corresponds to 9% of all studied eye injuries.

Adolescent↗
PubMed1987

Histopathologic and immunohistopathologic features of subretinal fibrosis and uveitis syndrome.

We studied histopathologic and immunohistopathologic features of an eye from a patient who had hypopigmented choroidal lesions with subsequent development of progressive subretinal fibrotic tissue associated with minimal signs of vitreal inflammation. A 24-year-old woman had a rapid and severe onset of the disease, which led to blindness within a few months despite treatment with corticosteroids and cyclophosphamide. Histopathologic studies disclosed a marked gliotic retina and thick subretinal fibrotic tissue as well as a granulomatous lymphocytic infiltration in the choroid. Electron microscopy demonstrated that the subretinal tissue was derived from retinal pigment epithelial cells. The immunoperoxidase staining showed similar proportions of T and B lymphocytes, indicating a relative increase of B cells. There was a predominance of the helper/inducer T lymphocyte subset in the infiltrating area. The Müller cells in the retina expressed class II antigens of the major histocompatibility complex.

Adult↗
PubMed1987

An epidemic of acute hemorrhagic conjunctivitis in the city of Sao Paulo.

This is a clinical and laboratory report on 98 patients with acute viral conjunctivitis who were referred to the Eye Clinic of the Escola Paulista de Medicina of Sao Paulo, Brazil, from February 1983 to February 1984. It was planned with the objective of confirming the importance of adenovirus and enterovirus 70 as etiological agents of viral conjunctivitis. The occurrence of an outbreak of acute hemorrhagic conjunctivitis during the summer of 1984 permitted a better study of enterovirus 70. In addition, we could demonstrate that sporadic cases, from March to July 1983, were caused by the same virus. This fact confirmed the idea that the spread of the disease was not related to the recent arrival of the virus in the community, but to weather conditions of heat and high humidity.

Adenovirus Infections, Human↗
PubMed1985

Experimental guinea pig ocular infection by Salmonella typhimurium.

The clinical, microbiologic, and cytologic features of the guinea pig model of keratoconjunctivitis with enterobacteria, Salmonella typhimurium were elucidated. Guinea pig eyes were instilled with S. typhimurium and the eyes were studied by biomicroscopy, culture, cytology, pathology, and electron microscopy. All animals developed moderate to severe conjunctivitis that was present in 18% of the animals on day 1. It became more intense, appearing in all of the eyes on day 10 and disappeared before day 30. The cultures for S. typhimurium were almost all positive on days 1 and 2, declined steadily to 10% on day 10, and were negative after that. A coarse, epithelial punctate keratitis was present in more than 90% of the infected eyes at some time during the experiment. The keratitis had a biphasic clinical course. The first peak correlated with the maximum culture results, but during the second peak only 10% of the cultures were positive. Electron microscopy of the cornea showed the S. typhimurium at the epithelial surface within surface epithelial cells during the early phases of infection. The later phase keratitis, with negative culture results, resembles the keratitis of Reiter's syndrome.

Animals↗
PubMed1984

T-lymphocyte subsets in the aqueous humor and peripheral blood of patients with acute untreated uveitis.

We evaluated T-lymphocyte subsets in 18 patients with active untreated uveitis and in 20 controls by monoclonal OKT (Ortho-Kung-T cell) antibodies. Both OKT4- and OKT8-positive cells were detected in the aqueous humor of patients with uveitis. The percentage of OKT4-positive cells (21.1 +/- 7.4) was larger than that of OKT8-positive cells (15.2 +/- 5.3) and the OKT4-OKT8 ratio was 1.40 +/- 0.3. A comparison of aqueous humor and peripheral blood cells from patients with uveitis showed diminished frequencies of OKT4- and OKT8-positive cells. The OKT4-OKT8 ratios were not significantly different. A comparison of peripheral blood cells from patients with uveitis and from controls showed that patients with uveitis had lower OKT4-OKT8 ratios. Lower percentages of OKT4-positive cells were also observed in the peripheral blood cells of patients with uveitis.

Acute Disease↗