BACKGROUND: Four human corneas that had undergone photorefractive keratectomy (PRK) and subsequent penetrating keratoplasty were examined by means of light and electron microscopy in an attempt to detect possible causes for complications after PRK. METHODS: Four eyes with a central corneal leukoma resulting from a previous PRK treatment underwent penetrating keratoplasty respectively 3 days, 3 months, 5 months, and 13 months after the refractive procedure. Different excimer laser instruments (Meditec MEL 50, Summit UV200, and VISX 20/20) had been used. The corneal buttons removed were submitted for light microscopy, electron microscopy and immunohistochemistry. RESULTS: An immature (one to two layers, basement membrane anomalies) but continuous epithelium was present even in the 3-day specimen; between six and eight epithelial layers could be seen in the 13-month specimen, which still presented an undulated aspect of the otherwise normal basement membrane. A continuous acellular collagen layer underlying the epithelium of the ablated area was detected in the superficial stroma of all examined corneas. No Descemet's membrane or endothelial alterations could be seen. CONCLUSIONS: Despite recovery of a continuous epithelial layer as early as 3 days after PRK, abnormalities of both epithelium and superficial stroma could be detected in all specimens, including the one obtained 13 months after the refractive procedure.

Adult↗

PubMedDate not supplied

[Bacterial pollution of the coastal water in the Province of Rome].

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Bathing Beaches↗

PubMedDate not supplied

[Adenolipoma (thyrolipoma) of the thyroid gland].

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Adenoma↗

PubMedDate not supplied

[Fetal alcoholic syndrome: a clinical case].

Fetal alcohol Syndrome (FAS) is a well recognized pattern of malformations, produced by a heavy and chronic intake of ethanol during pregnancy. The Authors report a clinical case of FAS, observed during an epidemiological study on alcohol abuse of pregnancy women. They describe the anomalies and malformations of a newborn by a heavy drinking mother, and of his seven year old brother. Finally, the Authors consider the toxicological and preventive aspects of problem: counselling women of child-bearing age to the dangers of alcoholic intake during the gestation period is a professional responsibility.

Child↗

PubMedDate not supplied

beta 1-Integrin expression and function in human bladder cancer cells: modulation by TNF alpha.

Cytofluorimetric and biochemical analysis in two different grade human bladder cancer cell lines showed that G3 EJ cells exhibited higher levels of alpha5beta1 and alpha6beta1 heterodimers, and the G2 RT112 cell line higher levels of alpha2beta1. Alpha6/beta4 receptor was detected only in RT112 cells. Adhesion assays with extracellular matrix proteins indicated that both cells bound to fibronectin, laminin and collagen 1, the adhesive properties being related to the integrin profile. Inhibition tests revealed that alpha5beta1 mediated adhesion to fibronectin, alpha3beta1 and alpha6beta1 to laminin, and that alpha2beta1 was the main mediator of adhesion to collagen I in both cell lines. In EJ but not in RT112 cells, tumor necrosis factor-alpha induced the upregulation of alpha2, which mediated increased adhesion to collagen I. The different effects of TNFalpha on the two cell lines were not attributable to differences in tumor necrosis factor responsiveness, as both cells expressed comparable levels of tumor necrosis factor receptor-1 and the tumor necrosis factor-inducible intercellular adhesion molecule-1.

Carcinoma, Transitional Cell↗

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Comparative study of sensitive and vegetative innervation of external and internal anal sphincter muscles in different mammals.

Proprioceptive innervation of the external anal sphincter muscle and the organization of the vegetative and sensitive nerve components of the internal and sphincter muscle have been studied in different mammals. The findings of typical muscle spindles in the external anal sphincter muscle were constant in the pig, frequent in the goat and cow, rare in the sheep and horse and absent in the roe and rabbit. In the pig, muscle spindles were observed in the entire extension of the muscle, while in the sheep, goat, cow and horse, the receptors were found only in the cranial portion of the muscle. In all the species studied, the internal anal sphincter muscle had numerous ganglion cells, isolated or grouped, and rare Pacinian, Pacinian-like, and Golgi-Mazzoni corpuscles. Their functional role has been hypothesized.

Anal Canal↗

PubMedDate not supplied

Neurotoxic effects of 3-acetylpyridine (3-AP) in the hamster (mesocricetus auratus).

The 3-Acetylpyridine (3-AP) is a neurotoxic that determines a selective destruction of inferior olivary nucleus in the rat. However, in the other animals (mouse, rabbit, guinea-pig, quail and chicken) the effect could be less selective in the mentioned nucleus and constant in other areas of the central and peripheral nervous system. This investigation means to expand the study of these neurotoxic effects to the hamster, species not yet studied. The intraperitoneal administration of 3-AP, at a dosage of 65 mg/Kg, determines in this animal stridulous breathing, coughing and ataxy. Wide sites of the nervous system show, by microscopical observations, pictures of shrinking cells, vacuolization of the cytoplasm, reduction or loss of Nissl stain affinity and neuronal mutilation. The neurotoxic effects are mostly evident in the motor nuclei of the cerebral trunk and in the ventral horns of the spinal cord. However, the inferior olivary nucleus appears undamaged or sparely involved.

Animals↗

PubMedDate not supplied

Interaction of natural killer cells with extracellular matrix induces early intracellular signalling events and enhances cytotoxic functions.

NK cells are endowed with a wide array of adhesion molecules which mediate their interaction with endothelium and extracellular matrix components. We have shown that cross-linking of beta 1 integrins and CD44 on human NK cells induces a signal transduction pathway involving both tyrosine kinase activation and the modulation of intracellular calcium levels. Our studies have also demonstrated the ability of beta 1 integrins and CD44 to upregulate both the spontaneous and the CD16-triggered cytotoxic activity of human NK cells. Although the molecular mechanisms responsible for this costimulatory activity have not been defined yet, our studies indicate that the simultaneous cross-linking of beta 1 integrins and CD44 results in a synergistic effect on CD16-mediated enhancement of intracellular free calcium concentration, and suggest that this may be relevant for the cooperation observed.

Cell Communication↗