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Biomedical subjects

S Bazin

Publications and source records attributed to S Bazin.

At least 37 records · Page 2Linked to original sources

[Combined cataract-glaucoma operations. Extracapsular extraction and trabeculectomy versus phacoemulsification and trabeculectomy].

This retrospective study was conducted to evaluate the results of Combined Surgery of Cataract and Glaucoma (triple procedure). The procedure of combined surgery were trabeculectomy and extracapsular extraction (14 eyes) versus trabeculectomy and phacoemulsification (15 eyes). The follow-up of both groups was at least 9 months and up to 16 months (mean: 12 months). The mean decrease of IOP was 12.4 mmHg and 8.9 mm Hg in the first and second group respectively. Instillation of Beta-blockers twelve months after surgery were more frequent in the first group (64.3%) than in the second (26.7%). Finally, the IOP values one year after surgery were equivalent in both groups (less than 19 mmHg in 93% of cases). The mean features to emphasize the delay of recuperation of the best corrected visual acuity: one month for phacotrabeculectomy, and three months for extracapsular with trabeculectomy. The frequency of complications was low in both groups. We observed more hyphemas but less secondary cataracts in the phacotrabeculectomy group. Phacotrabeculectomy could become a reference procedure for combined glaucoma and cataract surgery.

Aged↗

Vulvar vestibulitis syndrome: an exploratory case-control study.

OBJECTIVE: To assess the prevalence of genital bacterial infection among women with vulvar vestibulitis syndrome and to evaluate the association of several potential risk factors with the occurrence of the syndrome. METHODS: Fifty-seven women referred for dyspareunia who satisfied Friedrich's criteria and had symptoms for at least 6 months were recruited as cases. Controls included 173 patients without dyspareunia seen at a private clinic. Cases and controls were aged 18-35 years and were not pregnant. RESULTS: Among cases, the prevalences were low for genital infection with gonorrhea (0%), Chlamydia (0%), Trichomonas (0%), Mycoplasma (0%), Gardnerella (14%), and Candida (8.8%). Ureaplasma was detected in the Bartholin glands of ten affected women (17.5%). Human papillomavirus DNA was detected in only three cases (5.3%) based on polymerase chain reaction assays on vestibular biopsies. The relative risk (RR) of the syndrome was related to some aspects of sexual and reproductive history. In particular, the RR in women who had used oral contraceptives (OCs) early (before age 17) reached 11.0 (95% confidence interval [CI] 1.3-97.1) relative to those who had never used OCs. Women who had first intercourse at age 15 or earlier had a 3.3-fold increase in RR (95% CI 1.4-8.0) compared to those who had first intercourse at age 16 or later. CONCLUSION: Our data provide little support for the idea that infection causes the vulvar vestibulitis syndrome. Hormonal factors such as early OC use may be involved in the etiology of this condition.

Adolescent↗

[Tissular collagen polymerization (author's transl)].

The type of collagen reticulation exerts an influence on biological, physiological and mechanical properties of tissues, thus the utility of its study. Chemical techniques allow both localization and evaluation of levels and origin (Schiff base or aldol) of reducible bonds in collagen. Physical techniques allow evaluation of the thermolability or thermostability, as well as the degree of collagen reticulation in a given tissue for all collagen bridges. Results by these methods have shown that the mode of tissular collagen reticulation evolves from the embryonic phase to senescence, the rate varying as a function of the tissue and species of the donor. Thus, during tissular reparation, the newly formed collagen network itself undergoes transformations. Cicatricial tissue thus gives rise to an anisotropic zone in particular in terms of mechanical properties, in the organ. This can have grave pathological consequences. In addition to these wide areas of study, a certain number of specific diseases, frequently genetic, show pathological changes in collagen polymerization, the molecular mechanisms for which are now becoming better known.

Bone Diseases↗

Biochemistry and histology of the connective tissue of Dupuytren's disease lesions.

When compared to age-matched control aponeurosis, lesions of Dupuytren's disease contain higher contents of water, collagen and chondroitin-sulphate, as well as increased proportions of soluble collagens and of reducible cross-links; these indicate synthesis of new collagen. The lesions show also increased amounts of type III collagen and an increased hydroxylation and glycosylation of the reducible cross-links. All these parameters are characteristic of granulation and scar tissues. Type III collagen was located by means of immunofluorescence on thin argyrophilic fibres and also within the large fibre bundles which appeared to be disrupted into microbundles. The increase of type III collagen and the presence of myofibroblasts in the apparently unaffected aponeurosis show that the disease is widespread and suggest that it is initiated within the aponeurosis and propagated by the cells migrating along the collagen bundles.

Adult↗

Isometric tensions developed during the hydrothermal swelling of rat skin.

Isometric tensions developed in connective tissue under the influence of temperature have previously been measured by their effect on a "shrinkage" phenomenon observed along the main axis of the collagen fibers. A new device, built and tested in our laboratory enabled us to obtain isometric tension curves by measuring a "swelling" phenomenon observed in other directions. Curves recorded in the two systems have been compared. Shapes were unchanged and the parameters chosen to define these morphologies showed the same values in both types of experiments. The parameters, which are independent of maximal tension, were also found to be independent of the total collagen content of the sample. Interpretation of the results suggests that these parameters depend not only on the nature but also on the density of the collagen crosslinks. The new device is applicable to minute tissue samples, whatever their fragility and fiber orientation.

Aging↗

Collagenolytic activity of eosinophilic granuloma in vitro.

Lytic activity of eosinophilic granuloma and other tumours was studied in vitro on collagen substrate. Collagen degradation was measured through the release of hydroxyproline-rich peptides into the medium. The in vitro lytic action was at a maximum in the case of EG and was correlated with the presence of histiocytic cells.

Bone Neoplasms↗

[Variations in the hydrothermic contraction of the rat skin as a function of the age of the animals].

The tension developed in Rat skin by hydrothermal shrinkage is modified with ageing of the animals: the temperature of maximum tension decreases from birth to 1 month, then very slowly increases with age. At higher temperatures than that of maximum tension a relaxation occurs very rapidly in young Rats and in not yet senescent adult skins. These modifications appeared to be related to those of the nature of the intermolecular collagen cross-links with ageing.

Aging↗

Collagen of Dupuytren's disease.

1. In contrast to collagen from the aponeurosis of normal adult subjects, the nodules, contractures and apparently unaffected aponeurosis from patients with Dupuytren's disease contained substantial amounts of type III collagen. 2. The presence of type III collagen supports the previous proposal that the initial response to injury is the synthesis of an increased proportion of this form of collagen. The increased amounts in the apparently unaffected aponeurosis indicate the disease is not strictly focal but more systemic than is usually considered.

Collagen↗

Collagen and myofibroblasts of granulation tissue. A chemical, ultrastructural and immunologic study.

In granulation tissue produced in the rat by subcutaneous injection of turpentine oil or polyvynile sponge implantation, the great majority of fibroblasts (myofibroblasts) possess a contractile apparatus which makes them similar to smooth-muscle cells. Chemical analysis shows that these granulation tissues contain a high proportion of Type III collagen, a genetically distinct collagen normally associated with embryonic dermal tissue. Type III collagen may persist up to 9 months after sponge implantation and myofibroblasts are seen in granulation tissue by means of electron microscopy and immunofluorescence. When granulation tissue is resorbed 50 days after turpentine oil injection, myofibroblasts disappear and the dermis contains Type I collagen. The concurrent presence of myofibroblasts and Type III collagen suggests that myofibroblasts, in addition to their contractile activity, synthetize, at least in part, type III collagen.

Animals↗

Collagen in granulation tissues.

Collagen is abundantly synthesized in granulation tissues and reaches a concentration higher than in normal neighbouring tissues. Such newly formed collagen is characterized by an abnormally low solubility and an easy degradation by collagenases and collagenolytic cathepsins. The activities of these two types of enzymes are high (especially collagenases) in tissues of acute inflammations when the granuloma is resorbing. These activities are lower in sub-acute inflammation and the collagen content of the persistent granuloma remains high. The collagen synthesized in granulation tissues is cross linked by hydroxylysino-5-keto-norleucine, the stable cross-link of collagen in embryonic skin. It is progressively replaced by the two aldimine cross links of normal adult skin when the granuloma is resorbed (acute inflammations induced in rats; human normal scars). The cross link of embryonic skin, on the contrary, is permanently present in collagen of tissues of subacute, chronic inflammations (sponge implants in rats, human hypertrophic scars and keloids. Studies of the structure of alpha-chains revealed that type III collagen (embryonic collagen) is present in granulation tissues.

Animals↗

Urinary excretion of hydroxylysyl glycosides during acute inflammation in the rat.

1. Subcutaneous inflammatory granuloma were induced in young rats and the urinary excretion of hydroxyproline and hydroxylysyl glycosides was observed during the period of acute inflammation. 2. All collagen metabolites were increased in the urine and excretion of glucosyl-galactosyl-hydroxylysine was much greater than excretion of galactosyl-hydroxylysine in the first days. 3. It is argued that urinary glucosyl-galactosyl-hydroxylysine is probably derived from hydroxylysyl residues of soluble collagen. 4. This study affords new arguments in favour of the dermal origin of urinary glucosyl-galactosyl-hydroxylysine, at least in skin inflammation.

Acute Disease↗

Collagen polymorphism in human scars.

Collagen similar to the collagen found in embryonic skin (same intermolecular cross-links and same structure of the polypeptide chains) is synthesized in young human scars. Later on, in normal scars, this collagen is replaced by the collagen of adult skin progressively. In contrast, in hypertrophic scars, a high proportion of collagen of "embryonic" type is present permanently. In granulation tissues of chronic inflammation, experimentally developed in rats, similar "embryonic" collagen has been found ; these granuloma are proposed as a model in laboratory animals of human hypertrophic scars.

Animals↗

Characterization of the collagen of human hypertrophic and normal scars.

The collagen produced in response to an injury of human skin is initially stabilized by a cross-link derived from hydroxyallysine, and characteristic of embryonic skin. In normal healing there is a change over with time to the cross-link derived from allysine, which is typical of young skin collagen. In contrast, hypertrophic scars fail to follow the time-related changes of normal skin, but retain the characteristics of embryonic collagen, indicating a continued rapid turnover of the collagen. This is further supported by the high proportion of the embryonic Type III collagen present in hypertrophic scars.

Adolescent↗