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J Garcia-Tamayo

Publications and source records attributed to J Garcia-Tamayo.

9 recordsLinked to original sources
PubMed1996

Superficial bladder cancer: study of the proliferative nuclear fraction as a prognostic factor.

The expression of the anti-proliferating cell nuclear antigen (PCNA) was examined in bladder specimens from 48 patients with superficial transitional carcinoma, with the use of the PC10 monoclonal antibody. In vesical tumours with good clinical behaviour, we found a median PCNA positivity of 7.1% with a range of 5-25%. In vesical tumours with high incidence of recurrence, the median was 36.6% with a range of 15-80%. In vesical tumours with a strong tendency to invasion, the median positivity for PCNA staining was 68% with a range of 40-92%. In conclusion, we believe that using PC10 immunostaining to determine a nuclear proliferative fraction is a quick and simple method of studying the prognosis of patients who have vesical tumours of low grade and low stage.

Carcinoma, Transitional Cell↗
PubMed1977

Meningoencephalitis due to Acanthamoeba SP. Pathogenesis and clinico-pathological study.

Amebic Meningoencephalitis (AM) and Primary Amebic Meningoencephalitis (PAM) are infectious diseases essentially confined to the Central Nervous System (CNS) and caused by free-living amebas of the genus Acanthamoeba (A.) and Naegleria (N.) respectively. AM due to A. sp. (Acanthamoeba castellanii and Acanthamoeba culbertsoni) have been reported in chronically ill debilitated individuals, some of them under immunosuppressive therapy, or in immunologically impaired patients without a history of recent swimming in contrast to cases due to N. sp. which usually occurs in healthy, young individuals with a recent history of swimming in man-made lakes or heated swimming pools. AM due to A.sp. is characterized by a subacute or chronic granulomatous meningoencephalitis involving mainly the midbrain, basal areas of the temporal and occipital lobes and posterior fossa structures. CNS lesions in AM are perhaps secondary and the portal of entry in humans is probably from the lower respiratory tract, genitourinary system or skin reaching the CNS by hematogenous spread. The predominant host reaction is usually composed of lymphocytes, plasma cells, monocytes and multinucleated foreign body giant cells. Necrosis is moderate and hemorrhage scant or absent. Cysts as well as trophozoites may be seen within the CNS lesions. PAM is due to Naegleria fowleri and is characterized by an hemorrhagic necrotizing meningoencephalities with an acute inflammatory response. Only trophozoites are found in lesions. The portal of entry is through the olfactory neuroepithelium. CNS tissues fixed in formalin may be used for further identification and taxonomical classification of the causative protoza using immunofluorescent antibody techniques (IFAT) and electron microscopic methods.

Amebiasis↗
PubMed1971

Acid phosphatase activity in mouse brain infected with Venezuelan equine encephalomyelitis virus.

The mode of development of Venezuelan equine encephalomyelitis virus and the activity of acid phosphatase in the central nervous system of newborn mice were investigated. Precursor particles appeared to be formed in masses of viroplasm, migrating to the membrane of the Golgi cisterns and vacuoles or to the plasma membrane and being transformed into mature viral particles by budding. Mature viral particles were also found in the lumen of the blood vessels and around the myelin sheath of axons. Increased number of Golgi complexes and depletion of polysomes were the main ultrastructural alterations of the nerve cells. Acid phosphatase activity was found to be increased in the Golgi cisterns, vacuoles, and lysosomes of nerve cells. The presence of acid phosphatase activity in the rough endoplasmic reticulum and perinuclear cisterns suggests increased production of the enzyme in the nerve cells infected with Venezuelan equine encephalomyelitis virus.

Acid Phosphatase↗
PubMedDate not supplied

Cytologic and ultrastructural findings of a peculiar alteration in cervical cells from patients with human papillomavirus infections.

Inclusion bodies were previously found in Papanicolaou smears of patients infected by the human papillomavirus (HPV). To ascertain their origin, 12 biopsies from patients with colposcopic evidence of papillomatous lesions were studied by cytology and electron microscopy. In several instances, koilocytotic atypias and electron-dense masses included within epithelial cells were observed. Some of these epithelial cells appeared to be surrounded by other cells in a sort of concentric arrangement. The electron-dense masses were composed of intermediate filaments, vacuoles and electron-dense material. They seemed to be dyskeratotic cells. They can be compared with apoptotic bodies and may be related to a disturbance of the involucrin expression caused by the HPV infection.

Biopsy↗
PubMedDate not supplied

An electron microscopic investigation on the pathogenesis of human vaginal trichomoniasis.

The fine structure of Trichomonas vaginalis and its acid phosphatase activity in the vaginal medium was investigated with the aid of the electron microscope. The relationship among trichomonads, desquamated epithelial cells, macrophages and bacteria was examined with special attention directed towards their phagocytic behavior. Acid phosphatase activity was observed in the Golgi apparatus, phagolysosomes and in the chromatic granules of Trichomonas vaginalis. Macrophages and leukocytes also exhibited activity for acid phosphatase, particularly during phagocytosis. Phagocytosis and digestion of epithelial cells and bacteria by trichomonads was demonstrated. The study of trichomonads in the vaginal medium is considered to be an important approach towards the understanding of the pathogenesis of lesions induced by this parasite.

Acid Phosphatase↗
PubMedDate not supplied

Prognostic significance of high expression of proliferating cell nuclear antigen in patients with intestinal metaplasia.

Although some types of intestinal metaplasia are considered to be potentially pre-malignant lesions leading to gastric carcinoma, their high frequency and variability limit their usefulness as early markers of malignant progression. The present study was carried out to search for parameters which could be used in conjunction with histological diagnosis to identify groups of patients with a high risk for developing gastric neoplasia. The expression of proliferating cell nuclear antigen (PCNA), as revealed by immunohistochemical staining of anti-PCNA monoclonal antibody (PC10) in 82 endoscopic biopsy specimens, was compared with the histological classification of intestinal metaplasia, the biochemical composition of gastric mucins and the expression of blood group Lewis antigens. Statistically significant (p 0.001) correlation between the PCNA labelling index (the percentage of positive cells in more than 700 tumor cells per sample) and the histological type of intestinal metaplasia, the presence of sulphomucins, and the presence of anomalous Lewis a antigen was found. We conclude that a high PCNA-labelling index in the gastric mucosa, with a histological diagnosis of incomplete intestinal metaplasia, could constitute a good prognostic marker of the severity of the histologic lesion. These parameters, together with others such as the presence of sulphomucins and of cells expressing anomalous Lewis a antigen, may be used to define patients with a high risk of developing a gastric neoplasia.

Cell Nucleus↗