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Biomedical subjects

R E Gordon

Publications and source records attributed to R E Gordon.

At least 127 records · Page 7Linked to original sources

Chest X-rays and full lung tomograms in gynecologic malignancy.

Four-hundred-seventy-one patients with gynecologic malignancy were studied. All of these had chest x-rays at the time of staging and 323 had concurrent full lung pleuridirectional tomography performed. In no instance were pulmonary parenchymal metastases identified by tomograms when the chest x-ray was negative and tomography led to more equivocal readings than did the chest x-ray. The current study indicates that there is extremely low diagnostic yield of full lung tomography in gynecologic malignancies. Full lung tomography was poor in assessing the presence of small pleural effusions. The yield of positive chest x-ray at varying follow-up times was also examined. The yield has been expressed by site of origin of the tumor as well as by stage at initial diagnosis. Some of these yields are quite high. There is a very poor prognosis when pulmonary findings become evident, regardless of the site of origin of the tumor. More than one half of the patients who develop pulmonary abnormalities will be dead within one year.

Female↗

A 31P topical magnetic resonance study of embryonic development in hens' eggs.

A 31P topical magnetic resonance study of whole chicken's eggs in vivo is described. Resonances from adenosine triphosphate, phosphocreatine, inorganic phosphate and phosphorous storage protein were observed. These changed in relative intensity as the embryo developed. No ill effects due to exposure to radiofrequency radiation or magnetic fields were observed. It is concluded that topical magnetic resonance can make a useful contribution to the study of embryonic development in avian eggs.

Adenosine Triphosphate↗

Morphological aberrations of nutritionally deficient streptococci: association with pyridoxal (vitamin B6) concentration and potential role in antibiotic resistance.

A strain of a nutritionally deficient streptococcus was shown to undergo morphological aberrations according to pyridoxal concentrations in the growth medium. Filamentous rod-shaped cells, observed by electron microscopy, predominated in the presence of decreasing concentrations. Multiple invaginations in the outer cell wall suggested inhibition of binary fission. Penicillin antimicrobial studies performed in the presence of similar pyridoxal concentrations indicated a relationship between filamentous forms and penicillin susceptibility.

Cell Membrane↗

A freeze fracture study of Crohn's disease of the terminal ileum: changes in epithelial tight junction organization.

Freeze fracture replicas of the plasma membrane and tight junctions of epithelial cells of the terminal ileum from 10 patients with Crohn's disease involving the small bowel and from the terminal ileum of two patients without inflammatory bowel disease were studied to determine if significant morphological variations could be documented. Samples of diseased tissue were taken from: 1) macroscopically normal ileal resection margins, 2) pinpoint aphthoid ulcers, 3) small 5 mm ulcers, 4) cobblestone mucosa. Samples of ileal mucosa from the proximal margin of ileocolic resections for carcinoma of the right colon were identically processed and served as controls. Control specimens showed normal villus structures lined by absorptive and goblet cells linked to adjacent cells by four to seven tight junction strands, arranged as an anastomosing network of fibrils oriented perpendicularly to the long axis of the cell. Crohn's disease specimens taken from the cobblestone area displayed the greatest degree of tight junction disorganization. Tight junctions commonly formed bizarre patterns, were fragmented, and often showed misalignment in a direction parallel to the cell axis. Specimens taken from areas 2 and 3 displayed a less severe form of tight junction rearrangement. Junctional strand fragmentations, as well as areas of plasma membrane lacking strands, were apparent. The resection margins had minor irregularities in junctional structure in some, but not all, cases. The predominant alteration in those cases which showed change was varying degrees of strand fragmentation. We postulate that the tight junction abnormalities of epithelial cells from the terminal ileum of patients with Crohn's disease may contribute to a disturbance in barrier functions.

Adult↗

Ultrastructural pathology of Crohn's disease: correlated transmission electron microscopy, scanning electron microscopy, and freeze fracture studies.

The mucosa of the ileum or colon from 16 patients with active Crohn's disease was studied using transmission electron microscopy of thin sections, scanning electron microscopy, and freeze fracture electron microscopy. Electron micrographs of diseased tissue, as well as of grossly normal resection margins, were studied. Correlations of mucosal disease, as seen with the various ultrastructural techniques, were made and compared to controls. Alterations of epithelial cell tight junctions in freeze fracture replicas correlated with a decrease in the number of pinpoint contacts between adjacent cells in transmission electron microscopy preparations. Gap junctions in Crohn's disease did not vary with respect to structure or number, when compared to controls. Mucosal microulcerations, affecting 1 to 6 cells, were observed in transmission and scanning electron microscopy preparations. Possible freeze fracture electron microscopy correlates of microulcers consisted of replicas of cells completely devoid of tight junctional structures. "Aphthoid" type ulcers were studied with the various ultrastructural tools and were remarkable for several abnormalities of villi bordering the aphthoid ulcers, as well as surrounding villi. Transmission, scanning, and freeze fracture electron microscopy each provide unique and confirming data that may be used to construct a model for the pathophysiology of Crohn's disease.

Colitis↗

Carcinosarcoma and separate carcinoid tumor of the stomach. A case report with light and electron microscopic studies.

A carcinosarcoma of the cardia of stomach is reported. This is a rare entity which is of further interest because of an associated but distinctly separate carcinoid tumor. The main tumor showed distinct adenocarcinomatous and spindle cell components which collided in many areas. The sarcomatous nature of the spindle cell component was confirmed by ultrastructural studies. We have reviewed the literature and have not found a similar case.

Aged↗

Three-dimensional organization of microtubules and microfilaments of the basal body apparatus of ciliated respiratory epithelium.

This is a descriptive study showing the three-dimensional interrelationship of cytoskeletal elements at the apex of ciliated cells of rat respiratory epithelium. Tissue specimens were serially thin sectioned in various planes and examined by transmission electron microscopy. Thicker sections were also cut at various angles and analyzed stereoscopically. Other specimens were cleared of soluble molecules by glycerination or Triton-X100 treatment and sectioned as described above. It was found that C microtubules from the triplets of each basal body diverge from the A and B microtubules, run a short distance, and converge at the basal foot. These microtubules or other microtubules arising anew then dispersed deeper into the cytoplasm. The C fibers also interdigitated with other microtubules running perpendicular to them and parallel to the ciliated surface. Ten-nanometer intermediate filaments were organized in parallel sheets between adjacent basal bodies. Sixnanometer actin filaments were distributed throughout the apical cytoplasm. Neighboring basal bodies were linked to one another by microtubules and microfilaments. Basal bodies from each cell appear to be structured for stability, flexibility, and arranged to operate as a single unit.

Animals↗

Topical magnetic resonance.

Topical magnetic resonance (TMR) is a method of obtaining high-resolution NMR spectra from a selected, localized place within a larger object, by modifying the main magnetic field, Bo, using only static magnetic field gradients. TMR is described together with the scope of metabolic information that can be obtained non-invasively from animals and human beings.

Animals↗

Small cell anaplastic lung cancer presenting as an ovarian metastasis.

An unusual case of small cell anaplastic carcinoma of the lung, presenting as a pelvic mass, is presented. Histochemical and electron microscopic findings confirmed the diagnosis. The pathologic features and unique clinical characteristics are discussed with comments on the topic of metastatic ovarian tumors.

Adult↗

Immune localization of calmodulin in the ciliated cells of hamster tracheal epithelium.

Melachronous beating of cilia of epithelial surfaces of most respiratory airways moves the overlying mucous layer in a caudal direction. The molecular mechanisms controlling ciliary beat remain largely unknown. Calcium, an element in its cationic form, is ubiquitous in biological functions and its concentration is critical for ciliary beating. Calmodulin, a calcium-binding protein which regulates the activity of many enzymes and cellular processes, may regulate ciliary beating by controlling enzymes responsible for mechanochemical movement between adjacent peripheral microtubule doublets composing the ciliary axoneme. As a first step in describing a calmodulin-related controlling mechanism for ciliary beating, calmodulin was localized in the ciliated cells lining the respiratory tracts of hamsters by electron microscopy, using an indirect immunoperoxidase technique with anticalmodulin antibodies as the molecular probe. Thin-sections revealed calmodulin located on microtubules and dynein arms of the ciliary shaft, basal body, apical cytoskeletal microtubules, and plasma membranes in specimens fixed with 1 mM Ca+2. Specimens fixed with less Ca+2 (1 microM), Mn+2, Mg+2, and EGTA showed a diffuse pattern of calmodulin with loci of greatest densities on basal body microtubule triplets. Demembranated specimens showed a less specific localization on axonemal microtubules but only on cells fixed with Ca+2. Calmodulin, by binding calcium, may function in ciliary beating in the respiratory tract of mammals either directly or indirectly through its effects on the energy-producing enzymes and by control of Ca+2 flux through plasma membranes.

Animals↗

Water in malignant tissue, measured by cell refractometry and nuclear magnetic resonance.

It has been known that tumour-bearing tissues often have a significantly higher water content than the normal tissues from which they have been derived. Most of the evidence suggesting this in recent years has been obtained from methods employing nuclear magnetic resonance (NMR), which, although undoubtedly indicative of hydration, cannot at present be precisely quantified. Furthermore it has not been possible by these means to determine whether this overall increase in the water content of the tissue is principally an increase in the extracellular fluid or whether the water content of the tumor cells and the cells immediately adjacent to the tumours increases also. In this investigation, which is the first of its kind, a combination of NMR and immersion refractometry techniques have been used to examine the water content of normal and tumour bearing tissues. NMR measurements were made on pieces of normal and tumour bearing tissue from rat livers: intact living cells were also isolated from these pieces and their refractive indices measured by immersion refractometry from which the water content of their cytoplasm was calculated. It was found that all the cells so measured obtained from hepatomas had more water in their cytoplasm (usually over 5% more water) than any of the cells from normal livers; and that normal-looking liver cells taken from the vicinity of hepatomas also all had more water in them than those of normal liver cells, although the differences in this case were less. These results were closely parallel to those obtained by NMR measurements. It is therefore concluded that an appreciable proportion of the increase in the water content of the tissue as a whole that occurs during carcinogenesis, must, in this tissue, be an increase in intracellular water.

Animals↗

Regeneration of rat tracheal epithelium: changes in gap junctions during specific phases of the cell cycle.

Uninjured mitotically inactive tracheal epithelium has virtually no gap junctions. When the epithelium is stimulated to proliferate synchronously through a single wave of DNA synthesis and cell division, study of thin sections and freeze-fracture replicas by conventional transmission electron microscopy reveals that gap junctions are formed by the end of the DNA synthetic (S) phase. During the period of mitosis (M), the gap junctions disappear and are not again observed as the superficial cells undergo mucous and ciliary differentiation and normal pseudostratified architecture is restored. If the regenerative cells are continuously stimulated so they go through at least one additional S phase, gap junctions begin to reappear in G1 and reach peak numbers at the end of the second S phase. The correlation of the appearance of gap junctions in regenerating tracheal epithelium with a specific phase of the cell cycle and the absence of these junctions in cells in other phases of the cycle and in the differentiated progeny cells suggests that this surface feature plays a role in control of mitotic activity.

Animals↗

Electron microscopic localization of factor-VIII-related antigen in adult human blood vessels.

We have localized factor-VIII-related antigen, using immunofluorescence and electron microscopy, in adult human blood vessels. In addition to its presence in endothelial cells, the antigen was localized within subendothelium and the layers of elastic lamina closest to the lumen. Also, we provide the first morphological evidence that factor-VIII-related antigen is associated with collagen fibrils within the vessel wall. These studies suggest that this subendothelial factor-VIII-related antigen may play a role in the adhesion of platelets to subendothelial components following endothelial injury.

Animals↗