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Biomedical subjects

L Laroche

Publications and source records attributed to L Laroche.

At least 127 records · Page 7Linked to original sources
PubMed1997

Diagnostic value of fundus examination in familial adenomatous polyposis.

BACKGROUND: Multiple, bilateral lesions of congenital hypertrophy of the retinal pigment epithelium (CHRPE) have been described in patients suffering from familial adenomatous polyposis (FAP) since 1980. This study aimed to determine a reliable diagnostic criterion, based on the size and number of retinal CHRPE lesions, allowing the screening of patient carriers of the gene responsible for FAP. METHODS: 32 control subjects and 144 patients belonging to 85 FAP families were studied, divided into 124 carriers of the genetic alteration and 20 non-carriers. RESULTS: In carriers of the deleted gene, multiple, bilateral retinal lesions were consistently observed. Lesion situation, size, shape, and degree of pigmentation were variable however. A positive criterion for FAP was defined as the presence of at least four lesions whatever their size, or at least two lesions one of which is large. This criterion showed a high sensitivity (0.68) and a maximal specificity (1). Within each family, the retinal phenotypic expression was homogeneous. CHRPE lesions were observed in two thirds of the FAP families and absent from the remaining third. CONCLUSION: By using this new positive diagnostic criterion, fundus examination allows early detection of those children carrying the gene responsible for FAP in families positive at ocular examination.

Adenomatous Polyposis Coli↗
PubMed1997

ABO antigen blood-group compatibility in corneal transplantation.

Our objective was to evaluate the effect of ABO antigen blood-group compatibility on corneal allograft rejection. The 199 penetrating keratoplasties performed between 1985 and 1994 were analyzed retrospectively for ABO compatibility and the occurrence of irreversible allograft rejection. Of these, 72 were considered high-risk transplants, as there was significant vascularization of the recipient cornea or a history of irreversible corneal allograft rejection or both. One hundred twenty-seven were low-risk transplants. The data were analyzed by using the Kaplan-Meier method and compared with the log-rank test. Overall, the estimated 1-year graft survival was 83.9% in the low-risk group and 61.4% in the high-risk group (p = 0.001). The estimated 1-year rejection-free graft survival was 89.8% in the low-risk group and 67.1% in the high-risk group (p = 0.0002). In the high-risk group, graft survival (p = 0.008) and rejection-free graft survival (p = 0.0002) were higher in the ABO-compatible subgroup than in the ABO-incompatible subgroup. In the low-risk group, graft survival and rejection-free graft survival of the ABO-compatible and ABO-incompatible subgroups were similar. ABO compatibility may be effective in preventing irreversible allograft rejection in high-risk recipients.

ABO Blood-Group System↗
PubMed1997

Evaluation of the deswelling period in dextran-containing medium after corneal organ culture.

PURPOSE: To evaluate corneal structural modifications induced by the deswelling period in dextran-containing medium following organ culture. METHODS: Twenty human corneas were organ-cultured for 2 weeks and subsequently incubated in Exosol deswelling medium (Opsia, Toulouse, France) for 1-4 days. Corneas were studied by means of light microscopy, morphometry, and transmission electron microscopy. RESULTS: The deswelling period induced a statistically significant 8.4% endothelial cell loss and a 27.4% increase in the coefficient of variation. The endothelial layer remained intact. The basal epithelial cells displayed a flat appearance. Thin endothelial cells were observed in addition to dark vacuoles (the number of which increased with incubation time) with dense material and no mitochondrial swelling. Some basal epithelial cells and keratocytes were damaged on day 3 or 4. CONCLUSIONS: Preservation injuries induced by 1 or 2 days of incubation in deswelling medium are moderate. Three or 4 days of incubation result in more severe dextran-induced injuries. Consequently, the deswelling period should not exceed 2 days.

Aged↗
PubMed1997

[Value of implantation in the capsular bag during combined operation of penetrating keratoplasty and cataract surgery].

PURPOSE: To evaluate the clinical results of the triple procedure performed using phacoemulsification. METHODS: We prospectively studied 23 consecutive triple procedures carried out during a 3-year period. The average follow-up was 18 months. The main indications for grafting were Fuchs' endothelial dystrophy (30%) and infectious keratitis (26%). RESULTS: A capsulorrhexis was performed in 70% of the cases whereas a "can opener" was performed in the remaining 30%. A divide and conquer phacoemulsification method was used in 43% of the cases. Hydrodissection was used for lens removing in 27% of the cases. The posterior lens capsule was inadvertently broken and a flexible anterior chamber lens was inserted in one case. Twenty-two posterior chamber lenses were inserted in the capsular bag (16) or in the sulcus (6). The estimated 1-year graft survival was 76.8% overall, and 92.9% when high-risk recipients were excluded. Causes of graft failure were immune rejection (n = 4), persistent epithelial defect (n = 1) and uncontrolled glaucoma (n = 1). The average endothelial density during the second year was 1,401 cell/mm2. Average corrected visual acuity was 20/45 at 12 months. Average astigmatism was 3.9 D. No retinal complication was observed. CONCLUSIONS: In-the-bag placement of posterior chamber lens is a safe and useful technique during the triple procedure. Phacoemulsification may be useful when the nucleus is hard and voluminous.

Aged↗
PubMed1997

[Dural carotid-cavernous fistula with uveal effusion syndrome].

We report the case of a patient with a dural carotid-cavernous fistula. The examination showed a proptosis, a chemosis, an increased intraocular pressure and a choroidal detachment. The diagnosis was confirmed by arteriography. The treatment consisted of the embolisation of the feeders originating from the external carotid artery. The ocular improvement was only partial, but choroidal detachment regressed.

Arteriovenous Fistula↗
PubMed1997

[Surgical treatment of astigmatism caused by penetrating keratoplasty using the Hanna arcuate keratome].

PURPOSE: High postkeratoplasty astigmatism is a common postoperative complication which can limit the final functional result. Arcuate incisions are a possible surgical treatment. They can be performed with the arcuate keratome which provides regular incisions. The aim of this study was to evaluate the results obtained with this device in the correction of high postkeratoplasty astigmatism. METHODS: We retrospectively studied ten eyes operated for high postkeratoplasty astigmatism with the Hanna arcuate keratome. Arcuate keratomy procedures were performed on the graft button in all. Before surgery, mean uncorrected visual acuity was 0.07 +/- 0.05. Best spectacle-corrected visual acuity was 0.33 +/- 0.20 and mean subjective cylinder was 6.1 +/- 1.71 D. RESULTS: After one month postoperatively, the mean best spectacle-corrected visual acuity (0.45 +/- 0.20) was significantly improved (p < 5%) and mean subjective cylinder (2.85 +/- 1.29 D) was significantly decreased (p < 5%). Vector analysis showed a 5.59 D (+/- 3.63) mean astigmatism correction. Modifications of the spherical equivalent were not statistically significant. Astigmatism irregularity was not modified. CONCLUSION: Arcuate keratotomy carried out with the Hanna arcuate keratome is effective in reducing high postkeratoplasty astigmatism. It is easier to perform than the standard manual technique. However, astigmatism correction predictibility should be improved.

Adult↗
PubMed1997

[Cultures of corneal epithelium on hydrogel for synthetic epikeratoplasty].

PURPOSE: To improve the LLH480 hydrogel cytocompatibility and to assess the interactions between corneal epithelium and biomaterials. METHODS: Rabbit corneal epithelium organotypic cultures were carried out on hydrogel samples coated with fibronectin, laminin, type IV collagen, or heparan sulfate proteoglycan. The control group consisted of epithelial cultures carried out on hydrogel with no coating. Cellular migration was quantified, and statistically analyzed. 8-day cultures were processed for transmission electron microscopy. RESULTS: Epithelial migration on hydrogel was significantly increased (p < 0.001) in the heparan sulfate proteoglycan group, significantly decreased (p < 0.05 and p < 0.001) with laminin or type IV collagen coating, and showed no significant modifications in the fibronectin group. Transmission electronic microscopy showed a monolayer of epithelial cells adherant to the surface of the hydrogel. Deposit of extracellular matrix and sketch of adhesion focal points were also noted. CONCLUSION: LLH480 cytocompatibility can be improved by heparan sulfate proteoglycan coating.

Animals↗
PubMed1997

[Astigmatism after penetrating keratoplasty. Videokeratoscopic analysis on a series of 60 grafts].

PURPOSE: To study the factors which induce post keratoplasty astigmatism. To assess the reliability of different methods in the astigmatism measurement and to study the visual acuity predicting factors. METHODS: We retrospectively studied the corneal topography in 60 eyes with penetrating keratoplasty after suture removal, using the CAS* (Eye Sys). The diagnosis was keratoconus in 65% of the cases and bullous keratopathy in 15% of the cases. The graft was secured with a single running suture in 38.3% of the cases, interrupted sutures in 23.3% of the cases, or a combination of both running and interrupted sutures in remaining 28.3%. RESULTS: The suture method, diagnosis and surgeon did not influence subjective refraction nor visual acuity. The topographic pattern correlated with subjective cylinder (rs = 0.52 p = 0.02). The refractive power cylinder ("Holladay diagnostic summary") correlated well with subjective cylinder (rs = 0.81 p < 0.001) and visual acuity (rs = -0.63; p < 0.001). The Javal keratometry remains the best method to measure astigmatism axis (rs = 0.58; p < 0.001). CONCLUSIONS: The Holladay diagnostic summary (refractive power) is a useful tool for evaluating qualitative outcome of corneal transplantation.

Adolescent↗
PubMed1997

[Nevus of Ota associated with chronic glaucoma].

Oculodermal melanocytosis (nevus of Ota) is an abnormally large accumulation of pigment in ocular tissues as well as the skin in the distribution of the trigeminal nerve. Elevated intraocular pressure is a serious complication of this disease, as well as transformation to malignant melanoma. We report a case of nevus of Ota, documented clinically and histopathologically, associated with severe chronic glaucoma.

Adult↗
PubMed1996

Monitoring of 8-methoxypsoralen during extracorporeal photochemotherapy: evidence for a "first-dose" effect.

Therapeutic monitoring of 8-methoxypsoralen (8-MOP) was studied in 12 patients (age range 43-85 years, weight range 48-76 kg) treated for Sezary's syndrome by extracorporeal photochemotherapy (ECP) for 14-41 months. Before the beginning of each ECP cycle (2 sessions on consecutive days at about 4-week intervals), a blood sample was drawn to determine the 8-MOP plasma concentration 2 h after drug ingestion. Plasma 8-MOP levels were measured using a high-performance liquid chromatography method with spectrophotometric detection. Monitoring parameters (dose, 2-h plasma 8-MOP concentration) showed important interindividual and intraindividual variations. The 8-MOP dose ranged from 0.57 to 1.04 mg/kg. Intraindividual variations of 2-h 8-MOP levels ranged from 21% to 75%. Of the 652 measurements, 13% were < 100 ng/ml, the therapeutic threshold for effective ECP; in three of the seven patients, increasing the dose obtained levels exceeding the therapeutic threshold, i.e, the absorption was not saturable. Orthogonal regression analysis between plasma 8-MOP concentrations measured in two consecutive ECP sessions showed a first-dose effect: the 2-h plasma 8-MOP concentration was significantly lower after the first administration than after the second (approximately 1.26-fold). Because 8-MOP has been proven to be a potent suicide inhibitor of drug metabolism in rats and humans, it is possible that 8-MOP had an inhibitory effect on its own metabolism within the therapeutic dose range for ECP, which would explain in part the inter- and intraindividual variability in 8-MOP kinetics and first-dose effect.

Adult↗
PubMed1996

Modulation of HLA-DR and CD1a expression on human cornea with low-dose UVB irradiation.

PURPOSE: To evaluate the effects of low-dose UVB irradiation of HLA and CD1a expression and the toxic effects of UVB on human corneas. METHODS: 24 pairs of human corneas from 24 donors were studied. One cornea from each pair was randomly irradiated with UVB (100 mJ/cm2) after enucleation. All corneas were then organ-cultured for 2, 7, 14 or 21 days. Endothelium was studied after enucleation and organ culture. Following preservation, corneas were evaluated by means of light microscopy, morphometry and TEM. HLA and CD1a staining was performed using an immuno-alkaline-phosphatase technique. RESULTS: Endothelial cell loss during organ culture averaged 9.1% in the UVB group and 9.2% in the control group (NS). The number of rosette and reformation figures (p = 0.004) and the coefficient of variation (p = 0.014) were higher in the control group. Epithelial sloughing was more accentuated in the UVB group. We observed the same moderate ultrastructural injuries in both groups. In the epithelium, the average number of HLA-DR+ cells per field was 0.12 in the UVB group and 0.42 in the control group (p = 0.035). In the stroma, these figures were respectively 1.04 and 1.34 (p = 0.026). In the epithelium, the average number of CD1a + cells was respectively 0. 025 and 0.078 (p = 0.019). In the preservation mediums, the average percentage of CD1a + cells was 0.07% in the UVB group and 0.27% in the control group (p = 0.014). CONCLUSIONS: Low-dose UVB (100 mJ/cm2) decreases HLA-DR and CD1a expression of organ-cultured human corneas and induces moderate corneal injuries. Low-dose UVB might be useful for preventing allograft rejection.

Antigens, CD1↗
PubMed1996

Pilotropic cutaneous T-cell lymphoma without mucinosis. A variant of mycosis fungoides? French Study Group of Cutaneous Lymphomas.

BACKGROUND: In the course of mycosis fungoides, pilofollicular manifestations without mucinosis (papules, keratoses, comedones, or epidermal cysts) are rare (15 cases reported). Therefore, histological and clinical diagnoses may be difficult. The clinical course and histopathological and immunohistochemical findings in 9 patients are described. OBSERVATIONS: Pilofollicular lesions were present at the onset (n = 3), before (n = 3), or during a relapse of mycosis fungoides (n = 3). Comedones and epidermal cysts were most frequent (n = 5). They disappeared with lymphoma therapy (n = 4), therapy with isotretinoin (n = 3), or spontaneously (n = 1), or they persisted (n = 1). Clues to the histopathological diagnosis consisted of pilotropism of the infiltrate with minor alteration of the hair follicle walls. The infiltrate was monomorphous and composed of sezariform CD4+ lymphocytes. Pilotropic or peripilofollicular infiltrates, or the absence of infiltrate, were detected in consecutive biopsy specimens obtained from the same patient. The keratinocyte expression of intercellular adhesion molecule type 1 was observed in the hair follicle bulb in front of the pilotropic infiltrate but not in the epidermis. No staining was observed in biopsy specimens of 6 of 7 patients with follicular mucinosis, of folliculitis lesions, or of normal hair follicles. CONCLUSIONS: Our findings indicate the role of adhesion molecules in pilotropism leading to mechanical obstruction of the follicle by tumoral cells followed by hyperkeratosis and cyst formation. It remains to be determined if the expression of intercellular adhesion molecule type 1 is the cause or the consequence of pilotropism. By becoming more aware of it, this variant of mycosis fungoides is probably not so rare.

Adult↗
PubMed1996

Treatment of mixed cryoglobulinemia with recombinant interferon alpha and adjuvant therapies. A prospective study on 20 patients.

In order to evaluate the efficacy of interferon alpha (IFNa) in mixed cryoglobulinemia (MC), a prospective multicenter clinical trial was conduced in April 1992. It consisted of treating 20 clinically symptomatic MC patients with IFNa for 26 weeks. Hepatitis C virus (HCV) infection was detected in 16 patients. A complete or partial clinical remission was obtained in 12 patients (60%). Eleven of these 12 responders (91.6%) experienced a clinical relapse less than 12 months after the end of therapy. Side effects were noted in 10 patients (50%). It was concluded that subcutaneously administered IFNa does not provide long-term remission.

Adrenal Cortex Hormones↗
PubMed1995

Morphology, histology, and ultrastructure of human C31 organ-cultured corneas.

Our objective was to evaluate corneal structural modifications induced by corneal preservation in a C31 organ culture medium. Twenty-four postmortem human corneas preserved in C31 medium (CRTS, Besançon, France) for 2-21 days and 12 fresh postmortem human corneas were studied and evaluated by means of light microscopy, morphometry, and transmission electron microscopy (TEM). Endothelial cell loss during preservation averaged 9.2% (+/- 7.2%). Endothelial morphology displayed significantly more moderate alterations in the group of fresh corneas than in the group of preserved corneas. Endothelial morphometry resulted in a higher coefficient of variation (p = 0.002) in the preserved group but showed no difference for the average figure coefficient and average cell area. The histological study showed corneal swelling and epithelial sloughing in the preserved group. TEM displayed moderate preservation injuries, such as numerous vacuoles, mitochondrial swelling, and increased cell thickness. These results are consistent with previous findings that indicated that C31 medium induces moderate preservation injuries.

Adult↗