Morphological features and apoptosis in the left internal thoracic artery grafts before implantation.

AIM: A small number of left internal thoracic artery (LITA) grafts are occluded at 3 years after the operation or show more than 50% stenosis of the lumen. The purpose of this study is to examine factors related to the morphology of the wall and to the function of the cell population of LITA grafts before implantation, in order to evaluate their quality and the viability, in a follow-up examination. METHODS: Fifteen LITA grafts were examined with light microscopy, for their morphology, endothelial cell coverage, apoptosis and cell proliferation, scanning electron microscopy and transmission electron microscopy. RESULTS: Increase of the thickness of the intima (14.21+/-1.28 mm), mean thickness of media 160.37+/-11.97 mm, detachment of intima from media, presence of foam cells in the media, low endothelial coverage (40.638+/-16.864), increase of apoptosis in intima (46.38+/-13.46), sub-intima (29.3+/-8.54), media (34.91+/-6.05) and adventitia (40.21+/-5.36), blood cells penetration of the intima through disruptions between endothelial cells are findings of LITA grafts before implantation. Cell proliferation was not detected in the wall of any graft. Follow-up examination 6 months and 2.5 years after the operation showed normal function of LITA grafts. CONCLUSIONS: Besides of the wall injury and the initiated atherosclerotic lesions, LITA grafts are well functioning at the time of the follow-up examination. Maybe our findings are related to the later occlusion of the referred in the literature small number of LITA grafts.

Prebypass histological and ultrastructural evaluation of the long saphenous vein as a predictor of early graft failure.

BACKGROUND: Twenty percent of the long saphenous vein (LSV) grafts that are employed as coronary bypass conduits occlude during the first year after the operation. The aim of this study was to evaluate the morphological parameters of the LSV grafts before implantation as predictors for the early occlusion of the grafts. METHODS: Forty-two samples of LSV grafts were examined via light, transmission electron, and scanning electron microscopy and evaluated clinically and by angiography at 6 months and 2 years after the operation. Morphological parameters were statistically analyzed and examined for their significance on the viability of the vein grafts. RESULTS: Six (14.28%) of the examined grafts occluded within the first 6 months after the operation, and 11 grafts (26.19%) occluded within the first 2 years. The grafts that occluded at 6 months were characterized by thick intima (mean value, 206+/-32.29 vs. 67.44+/-10.17 in the group functioning normally and 98.42+/-34 in the group occluded within 2 years), low endothelial coverage (22.7+/-4.04 vs. 64.61+/-2.89 and 26.06+/-1.78 in the corresponding groups), and narrow lumen (46.73+/-9.69 vs. 527.18+/-45.78 and 204.26+/-16.5 in the corresponding groups). The presence of foam cells, edema, calcification, neovascularization, and thrombus in the lumen of the veins is frequently observed in the wall of the occluded vein grafts, whereas fibrosis does not seem to be related. CONCLUSIONS: LSV grafts with low endothelial cell coverage, stenosis of the lumen, and thick walls are at an increased risk of developing intrawall lesions that lead to early graft failure.

"Hanseniaspora uvarum" the ultrastructural morphology of a rare ascomycete, isolated from oral thrush.

Superficial fungal infections, including oral thrush, often affect aged full denture wearers and many individuals over 65 years old. The aim of this study was to examine the ultrastructural morphology of a very rare yeast, named Hanseniaspora uvarum/guillermondi, member of the Ascomycetes family, whose pathogenesis and behaviour is not widely known. The yeast was isolated from whitish lesions of the buccal mucosa of an 70 years old woman. The specimen was collected with a mouth swab and cultured in Sabourauds-Dextrose agar. The identification of the organism was performed on the Api 20C Aux system. The yeast colonies, after fixation in glutaraldehyde 3% for 1 hour were immersed in OsO4 1% solution for 1 hour and were "in tissue" stained with uranyl acetate. Ultrathin sections, were observed with TEM Jeol C x 100. Our ultrastructural observations showed that this yeast had a thick cell wall in which the outer surface appeared fuzzy. In some yeasts we observed multilayered intracytoplasmic membrane a figure which is not described as far as we know in any yeast. Many vacuoles were frequently observed in the cytoplasm and especially in the center of the oval shaped cells. Bilateral budding which form ascospores is identical for the morphology of this yeast.

Effect of prostacyclin PGI2 on cardiopulmonary bypass-induced lung injury.

Lung injury produced by cardiopulmonary bypass (CPB) is clinically characterized as postperfusion pulmonary dysfunction syndrome. The roles of humoral factors, altered perfusion modes and the occurrence of diffuse microembolism have been subjects of a number of studies. This paper presents the effectiveness of a platelet inhibiting drug, PGI2 in preventing occlusive microaggregates in the pulmonary circulation. In a series of experimental dog studies using a PGI2 dosage protocol of 10 ng/kg/minute for 30 minutes prior to the onset of CPB followed by 20 mg/kg/minute during CPB, the following effects have been observed: 1) Preservation of platelet numbers during CPB (p < 0.01 versus controls; n = 16). 2) Significant reduction in platelet aggregation during CPB (p < 0.01; n = 16). 3) Insignificant hypotensive effect at normal levels of peripheral vascular resistance (n = 16). 4) Occlusive fibrin, leucocytes and small platelet-based microaggregates obstructing pulmonary arterioles in six of the seven control dogs but in none of the dogs receiving PGI2 infusion. 5) No evidence of perivascular or intra-alveolar oedema, interstitial inflammatory cell infiltrates or haemorrhage was seen in either group of dogs. The controversy existing in relation to the possible therapeutic role of PGI2 and, in particular, its ability to prevent occlusive microaggregates in the arterioles and capillaries of vital organs should encourage further clinical studies of PGI2 and its derivatives during cardiac surgery.

Histochemical localization of salivary glycoproteins in the submandibular gland of aging rats.

It is known that submandibular glands produce serous saliva in the serous demilune cells and mucous saliva in the mucous acinar cells which is a viscous, rich in glycoproteins substance. The aim of this study was the comparative histochemical investigation of acid and neutral salivary glycoproteins in the acinar cells of the submandibular gland in adult and aging rats. Three groups of female Wistar rats were studied: a) young adult rats, 3 months old, b) aged rats 25 months old, c) aged rats 30 months old. Each group included 5 animals. The animals were sacrificed with ether in toxic dose. The submandibular glands were dissected and placed in 10% formaldehyde solution. After fixation they were embedded in paraffin. The paraffin sections were stained with various techniques. We used the: a) Alcian-Blue PH 2,5-Neutral Red b) Periodic-acid/Schiff/Diastase c) Alcian-Blue PH2,5 and Periodic-acid/Schiff/Diastase. We observed that the acinar cells of the aged submandibular glands were filled with acid glycoproteins, while the neutral glycoproteins were localized only in the group of the adult rats. Our results confirm the theory, that lithiasis and chronic inflammations of the submandibular gland, which often happen after the 4th decade of the life, are due to alterations of the mucosubstance composition of the acinar cells.

[Ultrastructural study of the action of concentrated solutions of chlorhexidine digluconate on cocci in salivary flora in vitro]. / Etude ultrastructurale de l'action des solutions concentrées de chlorhéxidine di-glucconate sur les coques de la flore salivaire "in vitro".

Chlorhexidine digluconate is a potent antibacterial compound widely used in stomatology. In this work the authors studied the ultrastructural alterations of cocci in salivary flora, treated "in vitro" with high concentrations of chlorhexidine digluconate (0.5%, 1% and 2%). The effect of chlorhexidine 0.5% on the cocci revealed rarefaction of the cytoplasm, ruptures of the cellular wall and alterations of the protoplasm in the form of "plasmoptysis" and "plasmolysis". Treatment of the cocci with higher concentrations (1% and 2%) of the drug caused a change in the appearance of the protoplasm, showing a general coagulation, damage of the cytoplasmic membrane and the cellular wall, malformation of the cell and disorganization of the nuclear chromatin. The ultrastructural alterations observed are in agreement with the results of preliminary biochemical studies.

[Descriptions and comparative changes of modifications on ultrastructure of cocci and bacteridium of saliva under "in vitro" influence of sparse and dense solutions of chlorhexidine di-gluconate]. / Perigraphe kai sygkritike analyse ton metabolon pou paraterountai ste lepte yphe ton kokkon kai bakteridion tes mikrobiakes chloridas tou saliou meta apo "in vitro" epidrase araion kai pyknon dialymaton diglykonikes chlorexidines. 3. Melete me to elektroniko mikroskopio.

In our investigation we have studied and analysed the modifications on the ultrastructure of the cocci and bacteridium of saliva under "in vitro" influence of sparse and dense solutions chlorhexidine di-gluconate. We noticed that the sparse solutions of the drug revealed ruptures of the cellular wall and of the cellular membrane as well as "plasmoptysis" and "plasmolysis". The protoplasm, showing a general coagulation, damage of the cytoplasmic membrane and the cellular wall and in concentrations of 1% and 2% we observed a disorganisation of the nuclear chromatin.

[Localization of protease inhibitors in the chorionic villi of the human placenta, by means of the immunoperoxidase technic]. / Localisation d'inhibiteurs de protéases dans les villosités choriales du placenta humain, révélée par la technique d'immuno-péroxydase.

Alpha-1-antitrypsin and alpha-1-antichymotrypsin have been studied in human placentas, from the first trimester to term pregnancy, by immunohistochemical method. Both proteinase inhibitors were localized to the cytoplasm of the villous syncytiotrophoblast, with a decreasing intensity of staining towards term pregnancy. The Hofbauer cells were intensely positive for intracellular alpha-1-antitrypsin and alpha-1-antichymotrypsin at all gestational ages. According to data of the literature we suggest that the existence of the proteinase inhibitors in the placental barrier possibly represents an important part in the defence mechanism of the placenta and may play a particular role in modifying the maternal immune response towards the foetus.

[Ultrastructural study of the distal convoluted tubule in the mouse embryo]. / Etude ultrastructurale du tube contourné distal chez l'embryon de souris.

This work constitutes a contribution to the ultrastructural study of the differentiation of the epithelium of the distal convoluted tubule, which has been poorly investigated. The study was realised on mouse embryos B1 C57 (14th, 16th, 18th and 20th day of gestation), on newborn and one month old mice. On day-16 the distal convoluted tubule was evident in the form of a cellular mass; the lumen appeared on day-18. On day-20, completely differentiated epithelial cells were observed in some distal tubules; those cells showed cytoplasmic processes in the apical part, and basilar plasma membrane invaginations, containing mitochondria with numerous cristae. The results of this ultrastructural study confirmed that the differentiation of renal epithelium is progressive and indicates the installation of the renal function before birth.