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L Mendez

Publications and source records attributed to L Mendez.

28 records · Page 2Linked to original sources
PubMed1987

Monomeric (7S) IgM found in the serum of rheumatoid arthritis patients share idiotypes with pentameric (19S) monoclonal rheumatoid factors.

Serum from some seropositive (RF+) rheumatoid arthritis (RA) patients contains relatively high concentrations of monomeric (7S) IgM molecules. Seven S IgM molecules fail to bind the Fc portion of IgG, unlike 19S IgM RFs that bind aggregated IgG in classical RF assays. Some pentameric IgM RFs are marked by crossreactive idiotypes (RCRI) defined by prototypic monoclonal RFs. In previous studies, we observed that a proportion of pokeweed mitogen (PWM) induced plasma cells from RA patients' blood lymphocytes express the major RCRI as assayed by indirect immunofluorescence with polyclonal anti-RCRI antibodies. In this study, 7S IgM obtained from three different RF+ RA patients inhibits specific anti-RCRI intracytoplasmic staining of PWM induced RF+ RA-derived plasma cells. These 7S molecules also block polyclonal anti-RCRI antibodies from reacting with red blood cells bearing 7S IgM molecules from RF+ patients with RA or Waldenstrom's macroglobulinemia. We conclude that some 7S IgM molecules in the serum of RF+ RA patients are marked by the major RCRI idiotype and are related to 19S monoclonal and polyclonal RFs.

Adult↗
PubMed1986

Morphologic features of hepatic injury in cardiac disease and shock.

One-hundred-forty postmortem liver specimens from patients with cardiac disease or pre-terminal hypotensive shock were examined in order to characterize the histopathologic features of ischemic and congestive hepatic disease. The study group included patients with arteriosclerotic, valvular or hypertensive heart disease, primary pulmonary disease with cor pulmonale, myocarditis, cardiomyopathy, and shock. The hepatic lesions included centrilobular congestion alone (10%), congestion with necrosis (77%), centrilobular necrosis with inflammatory reaction (neutrophil or mononuclear cell) (27%), cardiac sclerosis (48%) and regenerative hyperplasia (23%). Cardiac sclerosis, the most common form of hepatic fibrosis seen, consisted of eccentric thickening or occlusion of the walls of central veins and perivenular scars extending into the lobular parenchyma. Regeneration of liver cells was manifested by either liver-cell plate thickening within a retained cord-like framework or by nodular masses of hepatocytes (nodular regenerative hyperplasia). Only one case of developing cirrhosis was identified in this series. The morphologic features outlined in this study should provide a useful basis for the classification of liver injury in cardiac disease and shock.

Adult↗
PubMed1984

[Cryolabile calcium and contractility of rat auricle].

Cooling to 2 degrees C during 15 minutes rat auricles immersed into a calcium free Krebs-Ringer solution induced extrusion of intracellular calcium. the quantity of extruded calcium is able to restore the rythmic contractility of new auricles immersed in this medium when rewarmed to 37 degrees C. Apparently this calcium is not involved in the mechanism of muscular contraction and this liberation does not seem to be related to an inhibition of Na-K . ATPase coupled to the Na/Ca exchange.

Adenosine Triphosphatases↗
PubMed1983

Site specific cleavage of phi X-174 replicative form DNA after modification by N-acetoxy-N-2-acetylaminofluorene.

Three kinds of structural disturbances were found in an 88 base pair (bp) fragment of phi X-174 DNA after exposure to N-acetoxy-N-2-acetylaminofluorene (N-Aco-AAF). (i) Frequent strand scissions at two specific guanine sites on the 5' 32P-end-labeled fragment were identified by base sequence analysis. Scissions at these two sites were induced at neutral pH and they were not increased by treatment with apurinic endonuclease. They are an immediate consequence of N-Aco-AAF action and are not primarily apurinic sites. (ii) Alkali treatment with 1 M piperidine at 90 degrees C induced strand scissions at every guanine, demonstrating adduct slices, depurination and strand scissions. (iii) Adducted DNA was sensitive to single-strand specific nuclease digestion, suggesting unwound DNA. These studies indicate the prediliction of N-Aco-AAF for certain DNA sites and they suggest three kinds of DNA modifications which can be expected after adduction by this carcinogen. Some of the sites may be premutational carcinogen-induced DNA structural modifications.

2-Acetylaminofluorene↗
PubMed1977

Novel method for estimating the labeling index in clinical specimens with the use of immunoperoxidase-labeled.

The labeling index determined by [3H]thymidine autoradiography in cells from clinical specimens was compared with the percentage of the cells showing nuclear reactivity to immunoperoxidase-labeled antinucleoside antibodies. This nuclear immunoreactivity is specific for denatured or single-stranded DNA's and is detectable almost exclusively during DNA synthesis. Results with the two methods showed excellent agreement. The new method allowed rapid accurate assessment of S phase in the tumor cells from freshly isolated aspirated specimens as well as frozen sections, suggesting general applicability to estimation of the labeling index without autoradiography.

Adenocarcinoma↗
PubMedDate not supplied

Laser lithotripsy of difficult bile duct stones by means of a rhodamine-6G laser and an integrated automatic stone-tissue detection system.

This report describes the initial clinical implementation of a new laser lithotripter system capable of effective fragmentation of common bile duct stones with a high degree of safety provided by an integrated stone-tissue detection system. This system automatically terminates laser pulse transmission if tissue contact is sensed. Eighteen patients with giant or impacted common bile duct stones refractory to standard treatment techniques were treated via the endoscopic retrograde route using a rhodamine-6G dye laser with an integrated stone-tissue detection system. In the event of tissue contact, the stone-tissue detection system cuts off the laser pulse after 190 ns (after transmission of 5% to 8% of the total pulse energy). Nine patients were treated under cholangioscopic control, and nine patients were treated blindly under fluoroscopic control using only standard duodenoscopes with either a 6F standard endoscopic retrograde cholangiopancreatography catheter (4 patients), a 6.8F balloon catheter (3 patients), or a laser lithotriptor basket (2 patients). Laser-induced fragmentation was achieved in all 18 patients (100%). Sixteen of 18 patients (89%) became completely stone-free after completion of the treatment, including additional intracorporeal shock wave lithotripsy in five patients. The only major complications occurred in one fully anticoagulated patient with a prosthetic heart valve who developed significant hemobilia and transient cholangitis but recovered after conservative treatment. Laser lithotripsy using the rhodamine-6G dye laser plus stone-tissue detection system appears safe and effective and allows "blind" fragmentation of difficult common bile duct stones to be performed under radiologic control.

Adult↗