R. M. Laguens

Analysis of adenocarcinoma of the colon and rectum: detection of human papillomavirus (HPV) DNA by polymerase chain reaction

Objective  The aim of the present work was to evaluate the presence of human papillomavirus genotypes in malignant and normal mucosa of the colon and rectum in order to determine if a relationship exists between HPV infection and colon neoplasms.

Arteriogenesis Induced by Intramyocardial Vascular Endothelial Growth Factor 165 Gene Transfer in Chronically Ischemic Pigs

Exogenous vascular endothelial growth factor (VEGF) improves tissue perfusion in large animals and humans with chronic myocardial ischemia. Because tissue perfusion is mainly dependent on the arteriolar tree, we hypothesized that the neovascularizing effect of VEGF should include arteriogenesis, an effect not as yet described in large mammalian models of myocardial ischemia. In the present study we investigated the effect of intramyocardial plasmid-mediated human VEGF(165) gene transfer (pVEGF(165)) on the proliferation of vessels with smooth muscle in a pig model of myocardial ischemia. In addition, we assessed the effect of treatment on capillary growth, myocardial perfusion, myocardial function and collateralization. Three weeks after positioning of an Ameroid constrictor (Research Instruments SW, Escondido, CA) in the left circumflex artery, pigs underwent basal perfusion (single-photon emission computed tomography [SPECT] with (99m)Tc-sestamibi) and regional function (echocardiography) studies at rest and under dobutamine stress, and were then randomly assigned to receive transepicardial injection of pVEGF(165) 3.8 mg (n = 8) or placebo (empty plasmid, n = 8). All experimental steps and data analysis were done in a blinded fashion. Five weeks later, pVEGF(165)-treated pigs showed a significantly higher density of small (8-50 microm in diameter) vessels with smooth muscle, higher density of capillaries, and improved myocardial perfusion. These results indicate an arteriogenic effect of VEGF in a large mammalian model of myocardial ischemia and encourage the use of VEGF to promote arteriolar growth in patients with severe coronary artery disease.

Demonstration and characterization of HLA-DR positive cells in the stroma of human endometrium

The proportion of stromal cells expressing DR antigens of the HLA system or reacting with an anti-macrophage antibody was studied by immunohistochemical methods in human proliferative, secretory and post-menopausal endometria. DR+ cells showed a rounded morphology with short expansions and represented 13-25% of the stromal cells in the proliferative and 16-43% in the secretory endometrium. The cells reacting with the anti-macrophage antibody were similar to DR+ cells, but their number was between 1/2 and 1/10 of DR+ cells. In the post-menopausal endometria no DR+ cells or elements reacting with anti-macrophage antibody were observed. These results suggest that a significant proportion of endometrial stromal cells expressing type II histocompatibility antigens do not belong to the monocyte-phagocyte system and that their number is under hormonal regulation.

Role of macrophage inflammatory protein-1α (MIP-1α) in macrophage homing in the spleen and heart pathology during experimental infection with Trypanosoma cruzi

Abstract We investigated in vivo the effect of macrophage inflammatory protein-1α (MIP-1α) inhibition upon the cellular recruitment into tissue damage sites and spleen histology in mice acutely infected with Trypanosoma cruzi . Histopathological studies of spleen sections revealed a 68% decrease in macrophage/monocyte infiltration as a result of MIP-1α neutralisation. Moreover, a reduction in the number of plasma cells and immunoblasts was observed. However, antibody (Ab)-mediated blocking of MIP-1α failed to modify tissue parasite levels. Examination of myocardial sections showed an increase in inflammatory lesions in mice treated with anti-MIP-1α Ab. There was also an increasing trend in the number of amastigote nests in the myocardium of anti-MIP-1α-treated mice compared with controls. Administration of anti-MIP-1α Ab failed to affect either the extent of inflammatory infiltrates or the parasite count in liver and skeletal muscle. To the best of our knowledge, these data are the first in vivo demonstration that CC chemokine MIP-1α is involved in cellular recruitment during acute infection with T. cruzi , indicating that MIP-1α influences macrophage/monocyte influx into target organs.

Ultrastructural and immunohistochemical study of the human kidney in Argentine Haemorrhagic Fever

In six lethal cases of Argentine Haemorrhagic Fever (AHF) a disease caused by Junin virus, kidney samples were studied by means of immunofluorescent and electron microscopic techniques. — The ultrastructural studies showed that the distal and collecting tubes presented a large number of virus like intracytoplasmic particles. Those particles were present in the lumen of the endoplasmic reticulum cisternae and showed two distinct morphological aspects. Some of them were of high electron density and contained a few granules. The others were larger in size, electron lucid, and contained a variable number of ribosome like granules. Both types of particles originated from the endoplasmic reticulum wall by a process of budding. The presence of these particles was coincident with a severe cell damage which lead to necrosis and desquamation; and with large quantities of Junin virus antigen as demonstrated by immunofluorescence. — On the basis of these observations it is assumed that in AHF the cell damage is due to direct viral replication within the affected cells.

Herpes simplex virus and human papillomavirus infection in cervical disease in Argentine women.

Summary: The aim of the present study was to determine that prevalence of herpes simplex virus (HSV) type 1 and 2 in cervical samples from Argentine women and to assess the role of HSV-2 in cervical cancer. A sample of 79 normal and 200 neoplastic cervical tissues (35 invasive cervical carcinomas, 75 high-grade squamous intraepithelial lesions, 79 low-grade squamous intraepithelial lesions and 11 abnormal squamous cells of undermined significance) was analyzed for herpes simplex and human papillomavirus DNA using the polymerase chain reaction method. Viral genotyping was performed by single strand conformation polymorphisms and restriction fragment length polymorphisms. The overall prevalence of HSV was 21.5% in controls and 29% in cases. Among women with normal cytology, herpes simplex prevalence in HPV positive (20.8%) women was approximately the same as in negative (21.8%) women. HPV- and age- adjusted ORs of high-grade squamous intraepithelial lesions and invasive cervical carcinomas for HSV-2 were 1.4 (p = 0.6) and 1.6 (p = 0.5), respectively. The obtained results indicated that herpes simplex virus may not be involved in cervical cancer development. Future investigations are needed to provided conclusive evidence on the role of this pathogen in cervical cancer.

Effect of acriflavin on the fine structure of the heart muscle cell mitochondria of normal and exercised rats

Abstract The administration of neutral acriflavin to rats provoked the appearance of numerous myocardial mitochondria containing DNA fibres. The highest incidence of DNA-containing mitochondria was found at 4 and 6 h after drug injection. The association of acriflavin administration and acute exercise induced the appearance of a higher number of DNA-containing mitochondria as compared with the non-exercised controls, and prevented the increase in the volume fraction of mitochondria that occurs after exercise. These findings suggest that the appearance of intramitochondrial DNA fibres after acriflavin administration is the result of an inhibitory effect of acriflavin on the replication of mitochondrial DNA. On the basis of this interpretation it was suggested that acriflavin could be used as an “antimitotic drug” for mitochondria, and that both “mitotic index” and “mitotic time” could be calculated for the mitochondrial population in the same way as they are determined for whole cells after mitotic arrest with spindle poisons.

The small intestine in diabetes mellitus. Correlation of clinical phenomena to histomorphometric findings in peroral biopsy material

SummaryBiopsy material obtained from the first portion of the jejunum of 56 unselected diabetics and 21 normal controls was examined under the electron microscope (in 8 cases) or with a method of stereologic morphometry. Controls were found to have a villous volume (VVi) of 50.19±10.1%. All values below 40% were interpreted as an expression of deterioration of the mucous membrane. Altogether 12.5% of the diabetics showed total atrophy, and 20% had significant reduction of VVi. These changes did not correlate with intestinal disorders or other signs of diabetes. In total atrophy histochemical changes could be demonstrated. Microangiopathy was not observed in the intestinal mucosa.