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Biomedical subjects

M Baudrimont

Publications and source records attributed to M Baudrimont.

At least 37 records · Page 2Linked to original sources

Corneal endothelial cell apoptosis in patients with Fuchs' dystrophy.

PURPOSE: To investigate whether apoptosis plays a notable role in degeneration of corneal endothelial cells in patients with Fuchs' dystrophy. METHODS: Forty-seven corneal buttons from 41 patients with Fuchs' dystrophy were studied. Nucleus labeling, transmission electron microscopy (TEM), and TdT-dUTP terminal nick-end labeling (TUNEL) were used to detect apoptosis. TEM and TUNEL were performed on sections of all 47 corneal buttons, and nucleus labeling was performed on the last 10 corneas. Seven human donor corneas, two corneal buttons from two patients with keratoconus, and one corneal button from a patient with interstitial keratitis were used as negative controls for detection of apoptotic endothelial cells. Negative controls were studied by means of nucleus labeling, TUNEL, and TEM. RESULTS: In the nucleus labeling assay, the average percentage of apoptotic endothelial cells was 2.65% in the Fuchs' dystrophy group (n = 10) and 0.23% in the control group (n = 10; P = 0.0003). In the TUNEL assay, labeling of some endothelial cells was observed on 42 of 47 corneas in the Fuchs' dystrophy group, whereas it was absent on most specimens of the control group. In TEM, most endothelial cell nuclei had a normal appearance, and apoptotic endothelial cells featuring condensed nucleus and decreased cell size could be observed exceptionally. Some apoptotic cells were found in the basal epithelial cell layer by means of nucleus labeling, TUNEL, and TEM in the Fuchs' dystrophy group but not in the control group. CONCLUSIONS: This study suggests that apoptosis plays an important role in endothelial cell degeneration in Fuchs' dystrophy. Because of a lack of conclusive evidence of increased endothelial apoptosis by TEM, further studies are needed to ascertain this finding.

Aged↗

[Mooren ulcer].

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Adrenal Cortex Hormones↗

[Treatment of unilateral limbal stem cell deficiency syndrome by limbal autograft].

PURPOSE: To evaluate the improvement of the ocular surface after limbal autograft in patients with unilateral limbal stem cell deficiency related to chemical burns. MATERIALS AND METHODS: Limbal autograft was performed in five patients with unilateral limbal stem cell deficiency related to chemical burns. Thereafter, four patients underwent penetrating keratoplasty. The limbal graft was obtained from the fellow eye, and was secured with interrupted sutures. Patient follow-up ranged from 10 to 47 months. Limbus and corneas were studied by means of light microscopy. RESULTS: All five patients reported subjective improvement. Vascularization decreased in one cornea. Visual acuity improved in one eye and did not change in the remaining four eyes. After penetrating keratoplasty, graft reepithelialization was achieved after respectively 3, 4, 21, and 30 days. Light microscopy showed the presence of goblet cells in the limbal epithelium in four cases. After limbal autograft, the corneal epithelium was devoid of goblet cells in three out of four cases. CONCLUSION: Limbal autograft improves the ocular surface and the prognosis of subsequent penetrating keratoplasty in patients with unilateral limbal stem cell deficiency related to chemical burn.

Adult↗

[Intraperitoneal transplantation of isolated hepatocytes of the pig: the implantable bioartificial liver].

The general aim is to prepare a bioartificial liver to treat acute hepatic failure using allo- and xenogeneic hepatocytes, immunoprotected by macroencapsulation and transplanted into the peritoneal cavity. The goal of this study was to prepare a large amount of isolated porcine hepatocytes, to encapsulate them within biocompatible membranes for transplant in allo- and xenogeneic combinations and to examine the viability and functionality of the cells 6 weeks later. Hepatocyte isolation was performed in 12 kg pigs (n = 15) by dissociation of the liver with collagenase D (1 g) without oxygenation. Encapsulation of the hepatocyte suspension (10(7)/mL) was performed in hydrogel membranes AN69; hollow fibers (2 m x 0.8 mm) and flaskes (1.8 cm), and transplanted to Yucatan pigs (n = 4) and Lewis rats (n = 12). Six weeks later, they were removed to study the cell viability by histological examination, and the production of albumin by immunonephelometry. The rate of isolated hepatocytes was 38 +/- 5 x 10(9)/mL by liver of pig and the mean viability was 93 +/- 2%. Six weeks after transplantation, hepatocytes were viable, organized in lobules, and showed conserved albumin production. The same results were observed for allogenic and xenogeneic combinations. In conclusion, this method of liver dissociation allowed for preparation of a large amount of isolated hepatocytes from a single pig liver, theoretically sufficient to treat a patient with acute liver failure. Hydrogel membranes were well tolerated and allowed immunoprotection without immunosuppression. Transplanted hepatocytes remained functional. This work is an important step in progress toward clinical application.

Animals↗

The complication of retained intraocular recipient corneal button after penetrating keratoplasty.

PURPOSE: To describe the complication of retained intraocular recipient corneal button after penetrating keratoplasty. METHOD: Case report. A 27-year-old man was referred to us because of complications after penetrating keratoplasty on the right eye. Slit-lamp examination disclosed a clear graft with a second clear corneal button behind. RESULTS: A second penetrating keratoplasty was performed successfully on the right eye. Histologic examination showed an intact epithelium and stroma vascularization of the recipient corneal button. Immunochemistry of the recipient corneal button and the first donor corneal button was performed. CONCLUSION: Although the recipient corneal button remained inside the anterior chamber for 5 months, no epithelial ingrowth occurred.

Adult↗

Internal bioartificial liver with xenogeneic hepatocytes prevents death from acute liver failure: an experimental study.

OBJECTIVE: To demonstrate that a bioartificial liver, using allogeneic or xenogeneic hepatocytes protected from rejection by a semipermeable membrane, could prevent death from acute liver failure. SUMMARY BACKGROUND DATA: An implantable bioartificial liver using isolated hepatocytes could be an alternative to orthotopic liver transplantation to treat patients with acute liver failure. It could serve either as a bridge until liver transplantation or as the main treatment until recovery of the native liver. However, allogeneic or xenogeneic hepatocytes that could be used in clinical applications are spontaneously rejected. METHODS: Acute liver failure was induced in rats by 95% liver resection. Twenty-five million hepatocytes harvested in rats (allogeneic) or guinea pigs (xenogeneic) were encapsulated in a semipermeable membrane to protect them from rejection. The hollow fibers containing hepatocytes were transplanted into the peritoneum of recipient rats. Survival rates were compared between rats transplanted or not with hepatocytes. RESULTS: In groups not transplanted with viable hepatocytes, 73% to 93% of rats died after 95% liver resection. The mortality rate was reduced to 39% in rats transplanted with allogeneic hepatocytes and 36% in rats transplanted with xenogeneic hepatocytes. The bioartificial liver could be removed 1 month after transplantation, when regeneration of the native liver was complete. Allogeneic and xenogeneic hepatocytes remained viable. CONCLUSIONS: The implantable bioartificial liver was able to prevent death in this model of acute liver failure. This could be an important step toward clinical application of the method.

Animals↗

Evidence for survival and metabolic activity of encapsulated xenogeneic hepatocytes transplanted without immunosuppression in Gunn rats.

BACKGROUND: Hepatocyte transplantation could be an alternative to whole organ transplantation to correct enzymatic disorders. To this end, it would be of major importance to use xenogeneic cells without immunosuppression. The aim of this study was to investigate the survival and metabolic activity of encapsulated xenogeneic hepatocytes in the absence of immunosuppression. For this purpose, we used Gunn rats genetically incapable of bilirubin conjugation. METHODS: Xenogeneic (from guinea pigs) and allogeneic (from Lewis rats) hepatocytes (2x10(7)) were isolated, macroencapsulated in hydrogel hollow fibers made with an acrylonitrile-sodium methallyl-sulfonate copolymer, and transplanted into the peritoneum of Gunn rats without any immunosuppression. Plasma bilirubin levels were evaluated weekly. Bilirubin conjugates in bile and cell morphology were studied after 5 and 12 weeks, respectively. RESULTS: In Gunn rats transplanted with xenogeneic hepatocytes, a significant decrease in the serum bilirubin level was observed between 3 and 9 weeks after transplantation when compared with controls transplanted with empty hollow fibers: it fell to 62% of the initial level at weeks 5-7 (P < 0.01). A comparable result was observed in Gunn rats transplanted with encapsulated allogeneic cells. Bilirubin conjugates were observed in bile samples of rats transplanted with encapsulated hepatocytes. After explantation, hollow fibers appeared intact with minimal fibrosis. Cell viability and hepatocyte morphology were preserved. CONCLUSIONS: These results indicate that macroencapsulated xenogeneic hepatocytes can survive and remain functional for more than 2 months when transplanted in vivo in the absence of any immunosuppression.

Acrylic Resins↗

Peripheral neuropathy in human immunodeficiency virus-infected patients with the diffuse infiltrative lymphocytosis syndrome.

A subset of human immunodeficiency virus (HIV)-infected patients develop persistent CD8 hyperlymphocytosis and a Sjogren's syndrome-like syndrome associated with multivisceral CD8 T-cell infiltration, known as the diffuse infiltrative lymphocytosis syndrome (DILS). Patients with DILS tend to have higher CD4 cell counts, fewer opportunistic infections, and longer survival times than other HIV-infected patients. Peripheral nerve involvement in DILS has been poorly documented. We studied 12 HIV-infected patients with CD8 hyperlymphocytosis, DILS, and clinical signs of peripheral neuropathy. Two of 4 patients who were HLA typed were HLA-DR5 and 1 was HLA-DR6. All patients had the sicca syndrome and multivisceral involvement. The neuropathy was acute or subacute, always painful, and symmetrical in 8 cases. Electrophysiology was consistent with axonal neuropathy in 10 of 12 patients. Nerve biopsy showed marked angiocentric CD8 infiltrates without mural necrosis (12 of 12), and abundant expression of HIV p24 protein in macrophages (12 of 12). The HIV genome was detected by polymerase chain reaction in nerve homogenates. Zidovudine therapy was associated with improvement in 6 of 6 patients and steroid therapy was beneficial in 4 of 5 patients. No T-cell lymphoma was observed during follow-up, but 2 patients developed a primary B-cell lymphoma. We conclude that DILS neuropathy represents HIV-associated neuropathy, characterized by marked CD8 infiltration and abundant HIV in nerve, that improves with zidovudine or steroid therapy, and probably reflects a systemic host-determined and antigen-driven response to HIV.

Acquired Immunodeficiency Syndrome↗

Endophthalmitis after Lasiodiplodia theobromae corneal abscess.

BACKGROUND: Lasiodiplodia theobromae is an exceptional cause of human keratomycosis. PATIENT: We treated a 53-year-old man with fungal keratitis, which had been treated with topical betamethasone and gentamicin for 1 month, and endophthalmitis due to Lasiodiplodia theobromae. Despite intensive systemic, topical and intravitreal fungicidal treatment, enucleation had to be performed. RESULTS: The vitreous aspirate cultures were negative as of the second amphotericin intravitreal injection. However, histology revealed that the fungus was present in the cornea, ciliary body, iris and retina. CONCLUSION: The use of topical steroids may worsen the outcome of the infection.

Abscess↗

In-vitro development of corneal epithelial cells on a new hydrogel for epikeratoplasty.

This study demonstrates the adhesion and growth of bovine corneal epithelial cells on the surface of a new hydrogel. The hydrogel, containing 78% of water and 22% of AN-69 polymer (poly(acrylonitrile-sodium methallyle sulfonate)), was obtained by phase inversion of polymer-dimethylformamide solution in physiological saline (0.9% NaCl). Experiments were also carried out using hydrogel treated with arginine, human albumin and collagen IV. Covering of hydrogel samples by epithelial cells was completed within ten days, with good cell viability. The epithelial cells spread out and formed a consistent cell layer, confirmed by immunocytochemistry experiments against cytokeratins. Transmission electron micrographs showed numerous desmosomes between cells and the presence of some membrane differentiations at the cell/hydrogel interface. This study suggests therefore that the hydrogel might be suitable for the development of artificial epikeratoplasty grafts.

Journal Article↗

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↗

[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↗

[Nervous system lesions due to cytomegalovirus in AIDS].

Viral infections are observed with increasing frequency in HIV patients and one of the commonest viruses is cytomegalovirus. Clinical features of cytomegalovirus (CMV) encephalitis are non specific and radiology is rarely helpful. Polymerase chain reaction in cerebrospinal fluid has been shown to be useful for diagnosis of CMV encephalitis. CMV lesions in the nervous system are subdivided into six groups: Nodular encephalitis, myeloradiculitis, isolated inclusion-bearing cells, focal parenchymal necrosis, ventriculo-encephalitis and peripheral neuropathy. Clinicopathological aspects are only subdivided into four groups: Encephalitis, myelitis, myeloradiculitis and polyneuropathy. Diagnosis of cytomegalovirus encephalitis should be considered in patients with a CD4 count less than 100 cells/mm3. Recent developments in diagnostic techniques allow early recognition and more aggressive therapeutic approaches.

AIDS Dementia Complex↗

[Central nervous system infection due to Herpes simplex virus in AIDS].

Infections of the central nervous system by Herpes simplex viruses (Herpes simplex type 1 and Herpes simplex type 2) are uncommon in acquired immune deficiency syndrome and are often clinically and pathologically atypical. We have collected 11 cases of herpes simplex encephalomyelitis in AIDS patients reported in the literature. Only 3 of these cases presented with a typical, necrotizing, limbic encephalitis. Other clinicopathological patterns included ventriculitis, rhombencephalitis and myelitis. Ventriculitis and rhombencephalitis were usually due to infection by HSV-1, whereas myelitis was mostly due to HSV-2 infection. Distinction between the 2 types of virus is often difficult by immunohistochemistry due to frequent cross reactivity and usually requires tissue culture, in situ hybridization, or polymerase chain reaction. Association of HSV encephalomyelitis with productive infection of the central nervous system by the human immunodeficiency virus was only found in one case. In contrast, co-infection with cytomegalovirus was found in 9 of the 11 cases. One case also had had varicella zoster virus vasculitis, and another case also had a cerebral malignant non Hodgkin's lymphoma in which Epstein Barr virus genome was identified. This supports the view that concomitant herpes-virus infections of the central nervous system is a characteristic feature of AIDS.

AIDS-Related Opportunistic Infections↗