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Biomedical subjects

P Dighiero

Publications and source records attributed to P Dighiero.

At least 19 recordsLinked to original sources
PubMed2001

Histologic phenotype-genotype correlation of corneal dystrophies associated with eight distinct mutations in the TGFBI gene.

PURPOSE: To establish a phenotype-genotype correlation of various autosomal-dominant corneal dystrophies among French subjects. DESIGN: Retrospective molecular genetic study and clinicopathologic correlation. PARTICIPANTS: Forty-four subjects from 26 unrelated French families were included in this study, and 60 corneal buttons could be examined at the histologic and ultrastructural levels. METHODS: Light microscopy and transmission electron microscopy were performed on corneal specimens obtained during keratoplasty. Blood samples were collected for DNA analysis. MAIN OUTCOME MEASURES: After genomic DNA extraction from peripheral blood leukocytes of each family member, exons of the TGFBI gene were amplified by polymerase chain reaction (PCR), and the PCR products were directly sequenced on both strands. RESULTS: Four different mutations were found to be responsible for dystrophy of granular type (R555W, R124L, R124H, and R124L+delT125-delE126), three other different mutations produced a lattice type (R124C, H626R, and A546T), and the last mutation identified was associated with the honeycomb-shaped dystrophy (R555Q). Each subtype of dystrophy showed, histologically and ultrastructurally, specific characteristics that are easily recognizable. However, besides these stereotyped forms, differential histologic diagnosis of atypical forms remains difficult, and these forms could be misdiagnosed. CONCLUSIONS: The characteristic biomicroscopic appearance and histopathologic features of each "classic" dystrophy present a significant degree of specificity and generally provide an accurate diagnosis. However, atypical forms in which clinical and histologic data alone could be misleading, are unequivocally diagnosed after DNA analysis.

Cornea↗
PubMed2001

[Hyperkeratosis papilloma of the eyelid. An anatomic clinical case].

A clinicopathologic case of an 80-year-old male patient with a single cutaneous tumor on the upper part of the left eyelid is reported. It was a grayish and pigmented mass covered with a thick keratin layer, well circumscribed, and exophytic. After surgical removal, histopathology showed that the tumor had a papillomatous pattern and was growing under a thick layer of hyperkeratosis. It was a typical squamous cell papilloma. This tumor belongs to the benign eyelid tumor group and can be found on the eyelids of elderly people.

Aged↗
PubMed2000

A novel variant of granular corneal dystrophy caused by association of 2 mutations in the TGFBI gene-R124L and DeltaT125-DeltaE126.

OBJECTIVE: To characterize the molecular defect in the TGFBI gene in a French family affected with an atypical granular corneal dystrophy. PATIENTS: This family comprises 9 affected individuals across 3 generations without consanguineous marriage. METHODS: Light and electron microscopy were used to examine corneal buttons from patients. Exons of the TGFBI gene were amplified by polymerase chain reaction and sequenced directly using an automated method. Restriction digestion analysis and heteroduplex screening were performed to confirm that the mutations identified were not polymorphisms. RESULTS: Round or snow-flakes-like deposits that stained red with Masson trichrome and appeared as dense, rod-shaped structures were observed in the most anterior layers of the central stroma. All patients were heterozygous for the R124L mutation and a novel mutation predicting the deletion of 2 amino acid residues-threonine (T) and glutamic acid (E)-at codons 125 and 126. CONCLUSIONS: This French family is affected with a novel variant of granular dystrophy that is caused by a molecular defect in the TGFBI gene, reported here for the first time. CLINICAL RELEVANCE: These 2 mutations cause a novel variant of granular dystrophy that is intermediate in severity between the classical and superficial variant forms. Arch Ophthalmol. 2000;118:814-818

Adult↗
PubMed2000

Acyclovir-resistant bilateral keratitis associated with mutations in the HSV-1 thymidine kinase gene.

PURPOSE: To evaluate the contribution of molecular methods for the diagnosis of an acyclovir-resistant HSV-1 bilateral keratitis in an AIDS patient and to report a new point mutation in the nucleotide sequence of the thymidine kinase (tk) gene involved. METHODS: A 31 year old HIV-positive female presented with severe, active, bilateral and sight-threatening keratitis of 6 months duration, which was treated unsuccessfully with acyclovir. After corneal biopsy, samples were analysed by standard virological procedures, in situ hybridization, and PCR. The tk gene was cloned and subsequently sequenced. RESULTS: Conventional virological methods remained inconclusive. However, in situ hybridization and PCR rapidly confirmed the diagnosis of HSV-1 keratitis. The tk gene sequence revealed the presence of five variations previously described in two reference strains, but also a new point mutation at nucleotide position 431 which leads to an amino-acid change at position 144 that supported the hypothesis of a putatively altered functional form of the enzyme. Intravenous foscarnet treatment in an induction regimen was effective and cicatrization occurred within 3 weeks. CONCLUSIONS: PCR and in situ hybridization are effective and powerful techniques when other virological procedures are non-contributive, particularly in immunocompromised patients previously treated with antiviral drugs. The new point mutation identified in the tk gene may be associated with resistance to acyclovir.

AIDS-Related Opportunistic Infections↗
PubMed2000

A new mutation (A546T) of the betaig-h3 gene responsible for a French lattice corneal dystrophy type IIIA.

PURPOSE: To characterize the betaig-h3 gene defect in a French family affected with lattice corneal dystrophy type IIIA (LCDIIIA). METHODS: Histologic examination was performed from corneal buttons of two patients. Genomic DNA was extracted from leukocytes, and exons of the betaig-h3 gene were amplified by polymerase chain reaction to be directly sequenced. RESULTS: Numerous deposits were evident in the stroma and beneath the Bowman membrane, which had all the features of amyloid deposits. Analysis of exon 12 revealed a heterozygous G to A transition on codon 546. CONCLUSION: In contrast to Japanese patients, these French patients affected with LCDIIIA carry a distinct mutation of the betaig-h3 gene (A546T instead of P501T). Therefore, it is unclear whether different mutations could result in the same dystrophy or whether we are dealing with clinical heterogeneity of LCDIIIA.

Adult↗
PubMed2000

Clinical, histologic, and ultrastructural features of the corneal dystrophy caused by the R124L mutation of the BIGH3 gene.

OBJECTIVE: This study was designed to describe the clinical, histologic, and ultrastructural features of the corneal dystrophy associated with the R124L mutation of the BIGH3 gene. DESIGN: Retrospective clinical and histologic review of a new genetic mutation. PARTICIPANTS: Thirty-four patients from five unrelated French families with corneal dystrophy caused by the R124L mutation of the BIGH3 gene were studied at the clinical, histologic, and ultrastructural levels. Records of patients carrying this mutation were compared with those from three unrelated patients with corneal dystrophy of Bowman's layer (CDB) type 2 (R555Q mutation) and from three unrelated patients with classic corneal granular dystrophy (R555W mutation). INTERVENTION: The mutational genetic status of the BIGH3 gene was determined for each patient, and the histologic and ultrastructural data available after corneal graft were analyzed. MAIN OUTCOMES MEASURES: Genomic DNA was extracted from peripheral blood leukocytes. Exons 4 and 12 of the BIGH3 gene were amplified by the polymerase chain reaction (PCR), and the PCR products were directly sequenced. RESULTS: All 34 patients with the R124L mutation displayed the clinical, histologic, and electron microscopic features of the dystrophy previously described as a superficial variant of corneal granular dystrophy. Combining molecular genetics with clinical and histologic findings established a clear distinction between the R555Q and R555W dystrophies. CONCLUSIONS: The R124L mutation of the BIGH3 gene is associated with specific clinical and morphologic criteria. This indicates that molecular studies are needed for an adequate classification of corneal dystrophies. All criteria are presently available to segregate the dystrophy caused by the R124L mutation (known as CDB1) from the dystrophy caused by the R555Q mutation (known as CDB2).

Adult↗
PubMed2000

[Lyell's syndrome and its ophthalmologic manifestations in Cameroon].

BACKGROUND: To study basic epidemiological datas and ocular involvment during toxic epidermal necrolysis (T.E.N.) in Cameroonian patients. METHODS: Ten consecutive patients in the Central Hospital of Yaounde were included during a 4 years period. Anamnesis, clinical features, dermatological, ophthalmological and pathological examinations were done. Minimal follow up of 3 months. RESULTS: Mean age: 20.1 +/- 11.4 yrs (SD); culprit drugs: sulfadoxin (5/10), sulfamethoxazol (3/10); phenytoin (1/10). Mean of skin detachment: 41 +/- 17%. 2 patients died with sulfadoxin as culprit drug. Early ocular findings: conjunctivitis (all patients), symblepharon (1/8), ankyloblepharon (3 patients over 8 with sulfadoxin as culprit drug). All cases with ankyloblepharon (3) evoluated toward formation of a fibrovascular precorneal membrane with blindness. Two of the patients received a kerothoprosthesis on one eye. The 3 patients had a severe dry eye syndrome. CONCLUSION: TEN appears to be uncommon in Cameroon. Use of sulfonamides for treatment and prevention of malaria and AID'S opportunistic infections may increase the incidence of disease in tropical african areas. Ophthalmologists should be aware of early management of ocular manifestations in Lyell syndrome to avoid severe sequelae. That sequelae may be due to usual intensive healing in African patients. Severe corneal damages can be corrected only by keratoprosthesis.

Adolescent↗
PubMed2000

[Therapeutic photokeratectomy for the treatment of band keratopathy].

PURPOSE: This retrospective study was designed to investigate the therapeutic potential of phototherapeutic keratectomy (PTK) for the treatment of band keratopathy. PATIENTS AND METHODS: PTK was performed with the Excimed UV 200, (Summit Technology, Inc) on 27 eyes of 22 patients and with the Nidek EC5000 on 11 eyes of 10 patients with band keratopathy. Mean patient age was 57 years. The mean follow-up period was 19 months (ranged from 4 to 54 months). When possible, the change in best corrected visual acuity and spherical equivalent was evaluated at 6, 12, 18 and 24 months. RESULTS: Almost 90% of patients with smooth bands achieved visual improvement and 85% of patients with rough bands improved ocular discomfort. The mean hyperopic shift caused by tissue ablation was less than +2.0D after one year, for smooth bands. CONCLUSION: Excimer laser PTK is a safe and effective outpatient treatment and should be used as initial treatment for band keratopathy.

Corneal Diseases↗
PubMed2000

[Avellino dystrophy. Current diagnostic criteria].

We report a French family suffering from an Avellino corneal dystrophy diagnosed by using clinical, histological, ultrastructural and genetics findings. Our results indicate that direct corneal examination and routine histological examinations must always be associated with an assay for BIGH3 gene mutations to establish a modern and unambiguous diagnosis of a corneal dystrophy.

Adult↗
PubMed1999

[Keratitis].

A corneal inflammatory pathology could be a local process or could be an ocular manifestation of a multisystemic disease. For that reason, a correct diagnosis and an appropriate check-up should always be done. In rheumatoid arthritis, when ulcerative keratitis occurs, ocular morbidity is high, and more importantly, without appropriate systemic treatment, more than half of these patients die within a few years of onset of their disease.

Adjuvants, Immunologic↗
PubMed1999

Confocal microscopy in Bowman and stromal corneal dystrophies.

OBJECTIVE: To use confocal microscopy to demonstrate the similarity among three autosomal-dominant corneal dystrophies and the diversity of the deposit patterns within a single dystrophy. DESIGN: A prospective, comparative case series. PARTICIPANTS: Twenty patients (40 eyes) from 10 families suffering from Bowman or stromal dystrophy agreed to take part: 3 with Reis-Bückler dystrophy, 12 with granular dystrophy, and 5 with lattice type-I dystrophy. Of these, nine had recurrence in their grafts or after phototherapeutic keratectomy before the confocal examination. The confocal images of affected corneas were compared with those of ten normal control eyes (ten subjects). INTERVENTION: All patients were examined by slit-lamp biomicroscopy. Confocal microscopy was performed with Achroplan 40x/numeric aperture (NA) = 0.75 and 63x/NA = 0.9 water immersion objectives. Image analysis was used to identify the corneal epithelial and stromal deposits correlated with each disorder. MAIN OUTCOMES MEASURES: Selected images of the corneal layers were evaluated qualitatively for the size, shape, light scattering, and reflection of the deposits. RESULTS: Slit-lamp biomicroscopy showed stromal involvement in all affected eyes. Confocal microscopy identified epithelial deposits in 30% of the eyes and stromal deposits in all eyes. The deposits within the epithelium were revealed more clearly with the 63x/NA = 0.9 objective (higher numeric aperture). Some of the confocal findings near the Bowman layer were common for all three dystrophies. Normal control eyes showed no epithelial or stromal deposits, either by biomicroscopy or confocal microscopy. CONCLUSIONS: Confocal microscopy provides an in vivo evaluation of the deposits in the cornea, with a higher resolution than biomicroscopy. The confocal findings common to the three dystrophies may agree with previous hypotheses of the same genetic origin. It may be a useful adjunct to slit-lamp biomicroscopy, particularly when histopathologic studies cannot be performed.

Adolescent↗
PubMed1999

[Association of nevus and herpetic keratitis sequela. Apropos of an anatomo-clinical case].

Most conjunctival nevi are found during the two first decades of life. Beyond this period, the diagnosis must be assessed by histopathology. We report the case of a conjunctival nevus recently discovered in a 33-year-old patient who, additionally, was previously treated for herpetic disciform keratitis. The corneal scar decreased vision. A corneal graft and nevus excision were performed simultaneously. Histopathologic study confirmed the diagnosis of nevus and disclosed the corneal scar changes induced by herpes.

Adult↗
PubMed1999

[Phototherapeutic keratectomy in the treatment of Groenouw's type I corneal dystrophy].

PURPOSE: This study was designed to investigate the therapeutic potential of phototherapeutic keratectomy (PTK) for the treatment of corneal granular dystrophy. PATIENTS AND METHODS: PTK was performed with the Excimed UV 200, (Summit Technology, Inc) on a series of 27 eyes of 22 patients with corneal granular dystrophy. Mean patients' age was 34.6 years. The mean follow-up period was 31 months (ranged from 6 to 52 months). The changes in best corrected visual acuity and spherical equivalent were evaluated at 6, 12, 18 and 24 months. RESULTS: All of patients achieved visual improvement. Mean preoperative best corrected visual acuity (BCVA) was 20/100 and mean postoperative BCVA was 20/30 at one year. The mean hyperopic shift caused by tissue ablation was +/- 2.8 D after one year. CONCLUSION: Corneal grafting was the standard treatment for visually disabling granular dystrophy, but PTK has significant advantages over this procedure and must now be the standard method of managing corneal granular dystrophy when intervention is required.

Adult↗
PubMed1999

[Orbital lymphoma and AIDS. Apropos of a case].

We report the case of a 33-year-old HIV-seropositive male who had a large cell Epstein-Barr virus-associated non-Hodgkin's orbital lymphoma. A thorough medical examination enabled us to find on thoracic CT-scan a mediastinal lymph node involvement as large as 18 cm in diameter. The regression of the tumor was dramatic under chemotherapy with complete disappearance of the tumor and no recurrence was found after more than 21 months follow-up. We discuss the differential diagnosis with orbital infection.

Adult↗