[Coloration of cytologic thick sections containing biomaterials with silver methenamine. Usefulness for scanning electron microscopy].

Unlabelled: Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed a method allowing light and electron microscopic studies as well as microanalysis of the interface between bone and biomaterials after the sections glycoproteins have been stained with silver methenamine. Silver can be evidenced by SEM in back scattered mode.

Silver methenamine staining for scanning electron microscopy of bone sections containing biomaterials.

Sections of tissue containing orthopedic materials are currently used to study the compatibility of those materials and to perform electron probe microanalysis at the material-tissue interface. Identification of the cells in contact with the material by Scanning electron microscopy (SEM) is of interest. We have developed a method for staining cells and tissue structures embedded in polymethyl methacrylate with silver methenamine once the sections have been obtained.

Microwave-accelerated cytochemical stains for the image analysis and the electron microscopic examination of light microscopy diagnostic slides.

Recent studies in our laboratories have shown how microwave (MW) irradiation can accelerate a number of tissue-processing techniques, especially staining, to aid in the preparation of single specimens on glass microscope slides or coverslips for examination by light microscopy (and electron microscopy, if required) for diagnostic purposes. Techniques have been developed, which give permanently stained preparations, that can be studied initially by light microscopy, their areas of interest mapped, and computer-automated image analysis performed to obtain quantitative information. This is readily performed after MW-accelerated staining with silver methenamine by the Giammara-Hanker PATS or PATS-TS reaction.

Effects of carbamide peroxide on dental luting agents.

Vital bleaching of natural dentition using a 10% carbamide peroxide in solution may adversely effect restorative materials such as the luting agents. The purpose of this study is to examine surface structure and alterations of atomic weight percentages of elements in (a) zinc phosphate, (b) glass-ionomer, and (c) resin cements after contact with the solution. Dry samples of cement were immersed in a 10% carbamide peroxide solution (pH 4.

New observations on middle term hydroxyapatite-coated titanium alloy hip prostheses.

HA-coated hip prostheses were retrieved from elderly patients after death. Histological analysis, scanning electron microscopy and microanalysis by energy-dispersive X-ray spectrometry were performed on the same sections. These revealed good osseointegration of the implant material and evolution of bone and material.

Dental lesions in tumoral calcinosis.

Tumoral calcinosis (TC) is a rare inherited autosomal dominant metabolic disease manifested by elevated serum phosphorus and 1,25 dihydroxyvitamin D levels and periarticular cystic and solid tumorous calcifications. The dental findings in a large family have been critical in determining the genetic transmission of the condition. Radiographically the teeth have short bulbous roots, pulp stones and partial obliteration of the pulp cavity.

Biomaterials and biomedical devices.

This review discusses the factors important in the incorporation or integration of biomaterials and devices by tissue. Methods for surface modification and surface-sensitive techniques for analysis are cited. In vitro methods to evaluate the biocompatibility or efficacy of certain biomaterials and devices are presented.

Biomaterial-centered sepsis and the total artificial heart. Microbial adhesion vs tissue integration.

The principal barrier to the extended use of the total artificial heart is infection that is centered on the biomaterial constituting the prosthetic device and exacerbated by the surrounding damaged tissue. Ultrastructural studies of total artificial hearts removed from two patients indicate a failure of true tissue integration and diffuse, adhesive bacterial colonization of biomaterial surfaces. Biomaterials are, in part, susceptible to infection because, at the present state of the art, they are usually not well integrated with host tissue or, if hemodynamic, not optimally biocompatible or antiadhesive.

Epoxy-slide embedment of cytochemically stained tissues and cultured cells for light and electron microscopy.

A new method is described for embedding stained tissue sections, cells, cultured cells or organ cultures in a special polyethylene mold to form epoxy microscope slides (cast-a-slides). Cast-a-slides in which biological specimens are embedded may be examined by light microscopy and individual optimally stained cells or tissue areas selected for examination by various modes of electron microscopy or X-ray microanalysis. Cultured cells or organs can be grown, fixed, stained and embedded in epoxy in the same cast-a-slide mold.

Neutrophil pseudoplatelets: their discrimination by myeloperoxidase demonstration.

Neutrophils, especially in acute infection or the myeloid leukemias, may shed platelet-sized particles that can readily be distinguished from true platelets because they contain neutrophil myeloperoxidase. This enzyme, unlike platelet peroxidase, is not inhibited by glutaraldehyde. The myeloperoxidase and acid hydrolase levels and continuous plasma membranes of these cell-like particles suggest that they are functional cellular entities.

Acral lentiginous melanoma of the oral cavity.

Lentiginous melanomas may be classified clinicopathologically as either lentigo maligna melanomas or acral lentiginous melanomas. Lentigo maligna melanoma is generally characterized by its slow rate of growth, lateness of metastasis, and relatively good prognosis. Acral lentiginous melanoma, while demonstrating a radial growth phase which is histologically similar to that of lentigo maligna, appears biologically more similar to superficially spreading malignant melanoma once the vertical growth phase supervenes.

Effects of live Escherichia coli and Bacteroides fragilis on metabolism and hepatic pO2.

Rats were infused intraaterially with 10(9) live E coli, or 10(10) live B fragilis, or 0.9% NaCl solution. Within 6 hr or sooner E coli-treated rats extensive hepatic hypoxia (mean hepatic pO2 less than 5 mm Hg), hypoglycemia, lactacidemia, and microscopic evidence of sinusoidal damage and hepatocyte hypoxia.

Alterations of oxygen metabolism in experimental bacteremia.

To examine the mechanisms underlying organ failure and disordered cellular metabolism in sepsis, systemic oxygenation, hepatic tissue oxygenation, and hepatic mitochondrial metabolism were studied in rats subjected to an LD100 dose of E. coli bacteria administered intravascularly. The animals maintained normal systemic oxygenation and remained normotensive during the six-hour study period.

Human lingual tuberculosis. An ultrastructural study.

According to morphological criteria, the predominant cells from human oral tuberculosis granulomas are classified as monocytes, epithelioid cells, and multinucleated giant cells. The morphology of each cell type is related to its speculated function. It is theorized that macrophages and epithelioid cells represent an in vivo line of differentiation from undifferentiated monocytes and that giant cells form from a coalescence or syncytium of macrophages.

The ultrastructure of oral neuromas in multiple mucosal neuromas, pheochromocytoma, medullary thyroid carcinoma syndrome.

The ultrastructure of oral neuromas from 2 patients with multiple mucosal neuromas, pheochromocytoma, medullary thyroid carcinoma syndrome reveals numerous hypertrophic unmyelinated and myelinated axons, hyperplastic neurilemmal cells and associated collagen fiber formation. These tumors are described and compared ultrastructurally with neurilemmomas and neurofibromas as described by other authors. On the basis of this comparison, these tumors are not considered to be of neurilemmal origin.