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Biomedical subjects

J Cartwright

Publications and source records attributed to J Cartwright.

53 records · Page 3Linked to original sources
PubMed1988

Silicone lymphadenopathy associated with augmentation mammaplasty. Morphologic features of nine cases.

Silicone lymphadenopathy (SL)--defined as the presence of silicone in a lymph node--is a rare side effect of mammary augmentation either by injection of liquid silicone or by placement of a bag-gel prosthesis. Nine new cases in eight patients are herein reported and compared with six previously well-documented cases. The available data showed that SL was frequently detected as an incidental finding of no clinical significance during mastectomy and nodal dissection for associated breast carcinoma (nine cases), but may present as a painful or nontender enlarged lymph node (six cases). The latter presentation was almost always associated with a history of injection of liquid silicone or rupture of the prosthesis. All or some of the following findings were present in an affected lymph node: coarse vacuoles, fine vacuoles, and multinucleated giant cells. All lymph nodes contained a variable amount of an unstained, nonbirefringent, refractile material that, in seven of our cases, was shown to contain elemental silicon by energy-dispersive x-ray elemental analysis. In 312 lymph nodes collected from 18 routine cases of breast carcinoma, coarse vacuoles probably representing fat were found in 107 lymph nodes (34%); focal fine vacuoles were found in one (0.3%), and a single multinucleated giant cell was found in one (0.3%). In conclusion, SL probably will be encountered more frequently when cancer-prone age is reached by the susceptible population. In most cases, it is an incidental finding of no clinical significance. However, the histologic diagnosis can be made by observing characteristic light-microscopic changes, which may be supplemented in doubtful cases by energy-dispersive x-ray analysis.

Breast↗
PubMed1988

Eyelid pigment implantation: early and late histopathology.

Full-thickness sections of upper and lower eyelids were obtained from patients who had eyelid pigment implantation performed by one surgeon. These four patients represented eyelid pigment implantation at varying postoperative stages ranging from 6 months to 4 years. Light microscopic evaluation revealed pigment within dermis and superficial orbicularis muscle. Light and electron microscopic evaluation revealed the vast majority of the pigment to be located intracellularly, primarily within macrophages. No foreign-body reaction was seen around the implanted material. Electron probe analysis of the pigment showed only the presence of iron. Analysis of the unused pigment revealed small amounts of silica and magnesium. These substances could not be identified by electron probe analysis in the eyelid tissues.

Adult↗
PubMed1988

Distribution of elements in rat peripheral axons and nerve cell bodies determined by x-ray microprobe analysis.

X-ray microprobe analysis was used to determine concentrations (millimoles of element per kilogram dry weight) of Na, P, Cl, K, and Ca in cellular compartments of frozen, unfixed sections of rat sciatic and tibial nerves and dorsal root ganglion (DRG). Five compartments were examined in peripheral nerve (axoplasm, mitochondria, myelin, extraaxonal space, and Schwann cell cytoplasm), and four were analyzed in DRG nerve cell bodies (cytoplasm, mitochondria, nucleus, and nucleolus). Each morphological compartment exhibited characteristic concentrations of elements. The extraaxonal space contained high concentrations of Na, Cl, and Ca, whereas intraaxonal compartments exhibited lower concentrations of these elements but relatively high K contents. Nerve axoplasm and axonal mitochondria had similar elemental profiles, and both compartments displayed proximodistal gradients of decreasing levels of K, Cl, and, to some extent, Na. Myelin had a selectively high P concentration with low levels of other elements. The elemental concentrations of Schwann cell cytoplasm and DRG were similar, but both were different from that of axoplasm, in that K and Cl were markedly lower whereas P was higher. DRG cell nuclei contained substantially higher K levels than cytoplasm. The subcellular distribution of elements was clearly shown by color-coded images generated by computer-directed digital x-ray imaging. The results of this study demonstrate characteristic elemental distributions for each anatomical compartment, which doubtless reflect nerve cell structure and function.

Animals↗
PubMed1988

Videomicroscopic demonstration of defective cholinergic arteriolar vasodilation in atherosclerotic rabbit.

In atherosclerotic rabbits (SCLER), decreases in vascular resistance in response to acetylcholine (ACH), an endothelium-dependent agent, are suppressed, whereas those to nitroprusside (NP), an endothelium-independent vasodilator, are preserved. To determine whether defective vasodilation in SCLER is related to altered reactivity of resistance vessels, we visualized arterioles of rabbit cremaster muscle by videomicroscopy. Arteriolar diameter was monitored during topical (superfusional) delivery of ACh and NO, interventions that did not affect systemic hemodynamics. Diameter changes in response to NP (0.01-100.0 microM) did not differ between SCLER and controls; maximal dilations amounted to 110 +/- 10% (mean +/- SE). In contrast, responses to ACH (0.001-100 microM) differed; maximal dilations averaged 54 +/- 4% in SCLER and 124 +/- 9% in controls (P less than 0.001). These differences persisted after blockade with phentolamine, propranolol, and indomethacin. Phenidone and hydroquinone blockers of endothelium-dependent vasodilation, inhibited arteriolar dilation to ACH without affecting that to NP. Microvascular responses to intra-arterial drug were similar to those elicited by topical drug. Thus, hypercholesterolemia and atherosclerosis in the rabbit appear to produce a microvascular defect characterized by an impaired endothelium-dependent dilation and a preserved endothelium-independent dilation. This defect could play a role in limiting vasodilator reserve in atherosclerosis.

Acetylcholine↗
PubMed1988

Desmosomes of epithelial malignant mesothelioma.

Morphometric examination of desmosomes by electron microscopy may help distinguish epithelial malignant mesotheliomas (EMM) from adenocarcinomas (AC). The lengths of 225 desmosomes from 10 AC and 296 desmosomes from 12 EMM were measured. The mean desmosome length was not significantly different in the two groups. However, only one desmosome greater than 1-micron length was found among the 225 AC desmosomes, whereas seven such "giant" desmosomes were found among 296 EMM desmosomes (p less than 0.001). These long desmosomes ranged up to 4.2 micron in length and involved 4 of 12 cases of EMM. The longest AC desmosome was 1.34 micron. Thus, it is suggested that giant desmosomes be defined as measuring greater than 1 micron in length and that such desmosomes are found much more commonly in EMM than AC and tend to attain greater lengths in EMM.

Adenocarcinoma↗
PubMed1987

Intraluminal crystalloids in malignant salivary gland tumors (electron microscopic and X-ray microanalytic studies).

The ultrastructural, X-ray microanalytical, histochemical and immunocytochemical features of intraluminal crystalloids found in adenocarcinomas of the parotid gland have been studied. The crystalloids, putatively derived from an abnormal crystalization of salivary duct proteins, are considerably different from the crystalloids found in normal parotid glands, pleomorphic adenomas, and sialocysts.

Adenocarcinoma↗
PubMed1986

Intraluminal crystalloids in prostatic adenocarcinoma. Immunohistochemical, electron microscopic, and x-ray microanalytic studies.

Histochemical, immunohistochemical, electron microscopic, and x-ray microanalytic studies were performed on crystalloids within glandular lumina of adenocarcinomas of the prostate. In a review of light microscopic sections of 343 prostatic adenocarcinomas, unequivocal crystalloids were identified in 35 cases (10.2%). Immunohistochemical and ultrastructural studies revealed distinct differences between these crystalloids and the Bence Jones crystals of multiple myeloma: anti-kappa and anti-lamda immunostaining was negative, and the characteristic lattice-like architecture of Bence Jones crystals was not seen. Differences from corpora amylacea also were demonstrated. X-ray microanalysis did not elucidate the nature of the prostatic crystalloids, and their biochemical composition and mode of formation remain uncertain. Detection of the crystalloids in light microscopic sections nevertheless can aid in the diagnosis of prostatic adenocarcinoma, particularly when the tissue is distorted by crushing artifact, or if the tumor is so well-differentiated that it can be confused with atypical hyperplasia or inflammatory atypia. When intraluminal crystalloids are detected in prostatic glands that appear histologically benign or atypical, study of additional levels or a repeat biopsy should be undertaken.

Adenocarcinoma↗
PubMed1986

Smoke inhalation: an ultrastructural study of reaction to injury in the human alveolar wall.

This study was undertaken to determine the site of initial pulmonary injury in smoke inhalation. A hotel fire in Houston, Texas, resulted in the on-site deaths of 10 white people (2 to 62 years of age). All underwent autopsy examinations which included measurement of carbon monoxide (CO) and cyanide (CN) levels, as well as electron microscopy of lung samples. Average CO levels of 40% and CN levels of 0.6 ppm were obtained. In all cases, the lungs were heavy, hyperemic, and edematous with soot staining the tracheobronchial mucosa. Light microscopy showed soot, pulmonary congestion, and edema. Electron microscopy confirmed the presence of interstitial and intraalveolar congestion and edema. Carbon particles were also present, and occasionally were seen undergoing phagocytosis by alveolar macrophages. Intracellular edema with focal bleb and vesicle formation was prominent within Type I pneumocytes in 9 of 10 cases. Endothelial cells showed similar but much less severe changes, lacking the distinct blebs seen in the Type I cells. This investigation reveals that smoke, like ammonia inhalation and nitric acid instillation, appears to cause pulmonary edema by initial injury to the Type I pneumocyte.

Adolescent↗
PubMed1986

Correlation of plasma serotonin changes with platelet aggregation in an in vivo dog model of spontaneous occlusive coronary thrombus formation.

The role of platelets in contributing to occlusive coronary artery thrombus formation remains unresolved. A large number of studies have utilized in vitro techniques to study platelet aggregation. This report describes a model of spontaneous in vivo thrombus formation which involves application of current in the left circumflex coronary artery of the dog. Changes in mean coronary blood flow velocity (50% above control) are used to predict the point at which current can be discontinued without interrupting the ongoing process of thrombus formation. Thrombus formation proceeds to total vessel occlusion within 62 +/- 18 minutes after discontinuation of current. Coronary sinus plasma serotonin concentrations are used as an in vivo index of platelet aggregation during thrombus formation. Plasma serotonin levels increased only slightly above baseline levels during initial thrombus formation. Coronary sinus serotonin levels rose markedly after cessation of current, reaching a peak just prior to total vessel occlusion. The marked increase in serotonin concentration observed in the latter stages of thrombus formation strongly suggests that platelet aggregation is a significant factor in the evolution of an occlusive coronary thrombus.

Adenosine Diphosphate↗
PubMed1985

Microtubules in the heart muscle of the postnatal and adult rat.

In the postnatal rat heart, muscle cells continue to divide as well as increase in size. At the same time the cells in the soleus muscle (a slow skeletal muscle) do not divide, although they continue to grow in size. Since microtubules may have a role in orienting intracellular structures in muscle, we determined the numbers of microtubules/micron2 cross-sectional area in the rat heart papillary muscle during development. We have previously determined that in the soleus muscle, microtubule number/micron2 increases to a maximum at five to nine days of age, after which there is an abrupt decrease to a steady level characteristic of the adult [2]. The numbers of microtubules/micron2 in the heart were similar to those in the soleus muscle at the same age. The numbers of microtubules/micron2 increased from birth to a maximum at nine days, then decreased to a steady state. This decrease in microtubule number in heart muscle occurred at 9 to 11 days as in the soleus muscle. The distributions of microtubules are thus similar for cardiac and slow skeletal muscle, suggesting similar function(s) in these different muscle types.

Aging↗
PubMed1984

Perinuclear microtubules in postnatal rat heart.

Cytoplasmic microtubules can be divided into two subpopulations: 1) those adjacent to the nucleus (perinuclear), and 2) those distributed between the myofilament bundles (nonperinuclear). Previous observations (Cartwright and Goldstein, '83) indicate total cytoplasmic microtubule numeric density increases to a maximum at 5-9 days and decreases to the steady value of the adult muscle. We have examined the numeric density (mean numbers of microtubule profiles per micron2 cross-sectional area) of the perinuclear subpopulation and compared it to the numeric density of the total cytoplasmic microtubule population in postnatally developing rat papillary muscle ages 1, 3, 5, 9, 21, and 42 days, and adult. The perinuclear region was defined as the area around the nucleus which extends to the 0.273 micron from the nuclear envelope. The density of perinuclear microtubules did not change with postnatal development. Our study suggests that perinuclear microtubules are a separate and relatively stable subpopulation of the total population of cytoplasmic microtubules and may serve a function different from that of the more variable nonperinuclear microtubules.

Animals↗
PubMed1981

Intercellular bridges in the embryo of the Atlantic squid, Loligo pealei. II: Formation of the bridge.

Incomplete cytokinesis followed by the disappearance of the midbody and spindle remnant results in intercellular bridges between the cells of the blastoderm of the squid embryo. An electron microscope study of the morphology of the stages of development of the intercellular bridge is presented. Cytokinesis ceased as the furrow base reached a diameter slightly larger than the midbody. As furrowing stopped, a dense material accumulated to form a cylindrical sheath 50 nm thick, lining the inner surface of the furrow base. Proteolytic enzymes showed this material to have a significant protein component. As the midbody broke down, vesicles lined the inner surface of the bridge sheath. In this configuration, there was cytoplasmic continuity between the cells, and organelles appeared to pass through the bridge. The intercellular bridge could become temporarily closed. Vesicles entered the channel and fused with the vesicles lining the inner surface of the sheath. The vesicles enlarged until the channel became occluded with a series of transverse cisternae, the edges of which were embedded in the material of the sheath. When the bridge reopened, the transverse cisterna appeared to dissociate from the sheath, move out of the channel, and break down. Occasionally bridges were seen in which the bridge wall appeared distorted into lobes. It is suggested that such bridges might be in the process of breaking down, resulting in the final separation of the cells.

Animals↗
PubMed1980

Intercellular bridges in the embryo of the Atlantic squid, Loligo pealei. I. Cytoplasmic continuity and tissue differentiation.

In the post-gastrulation embryo of the Atlantic squid, Loligo pealei, the cells of the developing blastoderm are joined to each other by intercellular bridges which may provide a means of cytoplasmic communication between the cells. This paper describes an electron microscope survey of bridges in the developing blastoderm just prior to, and during, the onset of differentiation. The bridges are similar to those described in the gonadal tissue of many animal species and appear to result from incomplete cytokinesis followed by the disappearance of the spindle remnant. The bridges persist and chains of cells result which are generally branched and coiled. In the undifferentiated blastoderm the chains of cells show no apparent orientation to each other. However, in the apical blastoderm undergoing differentiation, chains of bridged cells appear to coincide closely with the developing mantle and shell gland primordia. The configuration a chain of cells assumes depends upon the degree of branching (i.e. the number of cells having three bridges) and the degree of coiling of the chain. Whereas coiling is probably affected by the crowding of neighboring cells, both branching and coiling appear to be functions of spindle orientation relative to previous bridges. During mitosis the bridges appear to become occluded by systems of transverse membranous cisternae, and mitotic nuclei are thus isolated. However, the bridges apparently re-open during G1, and during periods of protein synthesis the cells within a group share a common cytoplasm. It is suggested that gene products are shared and protein synthesis of the entire bridged group may be synchronized. As the sharing of control molecules may also be facilitated, these essentially syncytial groups may respond uniformly to inducers from the yolk syncytium, or other tissues and differentiation may be synchronized within the group.

Animals↗
PubMed1971

Ultrastructural analysis of mitotic spindle elongation in mammalian cells in vitro. Direct microtubule counts.

The mitotic spindle of many mammalian cells undergoes an abrupt elongation at anaphase. In both cultured rat kangaroo (strain PtK(1)) and Chinese hamster (strain Don-C) fibroblasts, the distance from pole to pole at metaphase doubles during anaphase and telophase. In order to determine the organization and distribution of spindle microtubules during the elongation process, cells were fixed and flat embedded in Epon 812. Selected cells were photographed with the phase-contrast microscope and then serially sectioned perpendicular to the major spindle axis. Microtubule profiles were counted in selected sections, and the number was plotted with respect to position along the spindle axis. Interpretation of the distribution profiles indicated that not all interpolar microtubules extended from pole to pole. It is estimated that 55-70% of the interpolar microtubules are overlapped at the cell equator while 30-45% extend across the equator into both half spindles. This arrangement appeared to persist from early anaphase (before elongation) until telophase after the elongation process. Although sliding or shearing of microtubules may occur in the spindle, such appears not to be the mechanism by which the spindle elongates in anaphase. Instead, our data support the hypothesis that spindle elongation occurs by growth of prepositioned microtubules which "push" the poles apart.

Animals↗