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M J Phillips

Publications and source records attributed to M J Phillips.

At least 145 records · Page 8Linked to original sources
PubMed1986

The use of cytoskeletal characteristics of tumor cells for the diagnosis of colon and breast adenocarcinomas.

The cytoskeleton of colon (11 cases) and breast adenocarcinomas (9 cases) was characterized with the use of immunohistochemistry on tissue sections and one- and two-dimensional (2-D) gel electrophoresis of cytoskeletal extracts of tumor cells. By immunofluorescence, antibodies to epidermal cytokeratin (CK) and Mallory body CK recognized cytoplasmic filaments +/- desmosomal contacts, respectively, in both colon and breast adenocarcinomas. In addition, cytoskeletal extracts of both tumors showed similar CK polypeptides by 2-D gel electrophoresis. By immunoperoxidase, anti-actin antibody stained the apical margin of tumor cells in eight (73%) colon adenocarcinomas and four of five metastases, while diffuse cytoplasmic staining was seen in only one (9%) breast adenocarcinoma and not in five metastases. With 2-D gel electrophoresis, a cytoskeletal-associated doublet polypeptide was found in seven (64%) colon adenocarcinomas but not in the breast adenocarcinomas. By immunoblotting, the doublet did not consist of CK polypeptides, vimentin, or type IV collagen. These findings may facilitate the differentiation of colon and breast adenocarcinomas.

Actins↗
PubMed1986

Prevention of cyclosporine (CyA) nephrotoxicity by synthetic prostaglandins.

Acute and chronic nephrotoxicity directly attributable to cyclosporine (CyA) administration remains an obstacle to its successful use. The studies presented in this report characterize the cytoprotective properties of 16,16-dimethyl prostaglandin E2 in a lethal CyA-induced nephrotoxic rodent model. Wistar-Furth rats (200-250 g) receiving CyA alone (100 mg/kg/day) showed marked deterioration in renal function with severe histologic renal lesions and death of the majority of animals by day 7. The prostaglandin treated group (10/micrograms/kg/day) administered concomitantly with CyA demonstrated near normal renal function and histology by the eighth day after CyA discontinuation, and in a significant improvement in animal survival of 85% (p less than 0.001, n = at least 20 rats/group). These studies demonstrate a novel approach to a major problem with cyclosporine and should have exciting clinical potential.

Animals↗
PubMed1986

Acute phalloidin toxicity in living hepatocytes. Evidence for a possible disturbance in membrane flow and for multiple functions for actin in the liver cell.

Actin filament based cell functions were examined in freshly isolated hepatocytes using phalloidin as an inhibitor. In particular, cell motility events, namely, surface bleb formation and canalicular contractile movements, were assessed and compared with morphologic changes in the cells. Phalloidin (in 0.1, 1.0, and 10.0 micrograms/ml dosages) was added to the culture medium 4 hours after isolation of the hepatocytes. Cell motility was recorded with time-lapse cinephotomicrography, and the morphologic changes were evaluated by phase-contrast optics and by transmission electron microscopy of serial sections. Membrane-bound pericanalicular cytoplasmic vacuoles appeared first, followed by cytoplasmic protrusions at the cell surface. Vacuolar membrane continuities with the canalicular membrane were noted, and later, with other regions of the cell surface, such that large tortuous irregular membrane-bound canals are seen on serial sectioning to link extracellular and canalicular spaces. These findings suggest a possible disturbance in membrane flow. Canalicular motility was greatly reduced and was dose-dependent. The time-based difference in the changes at the canalicular and sinusoidal surfaces may be indicative of different functions and/or sensitivities of the actin filaments within the liver cell.

Actins↗
PubMed1985

Adequacy of management and severity of asthma in children attending a summer camp.

To assess the adequacy of therapy in asthma, 46 children with asthma attending a summer camp were asked to complete a questionnaire about their symptoms and the treatment that they had received. Each child's height, weight, forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were measured. According to defined criteria of symptom severity the children were categorized as suffering from severe (48%) or mild (52%) asthma. The mean FEV1/FVC ratio (P less than 0.05) and the mean FEV1 were lower (P less than 0.02) in the children with severe asthma compared with those with mild asthma. In the group with severe asthma, 68% of the children were considered to be receiving suboptimal therapy; 45% had never had their FEV1 or FVC measured. Among those who were receiving suboptimal therapy, 40% had measurable airflow obstruction compared with 17% of children with mild asthma. Because poor management of asthma remains common in children, the need to make doctors and parents aware of the fact that suboptimal therapy may contribute significantly to the morbidity of the condition is emphasized.

Adolescent↗
PubMed1985

An ultrastructural analysis of dog mastocytoma cells and normal mast cells.

A well-differentiated dog mastocytoma was characterized ultrastructurally using morphometric, histochemical, and biochemical methods. The ultrastructure of cells in the intact tumor was compared to the morphology of cells disaggregated from the tumor and cultured for periods as long as 4 weeks and to normal dog connective tissue mast cells. Most of the tumor cells contained histamine (mean = 5.81 pg/cell), demonstrated chloroacetate esterase activity histochemically, stained metachromatically with toluidine blue, and were similar in ultrastructure to normal dog mast cells. The proportion of mast cells in this tumor averaged 67%; eosinophils, fibroblasts, plasma cells, and macrophages also were present. The mean diameter of mast cells (12.79 micron) and the mean diameter of their cytoplasmic granules (473 nm) were similar to those reported for mast cells and mastocytoma cells from various species. The heterogeneity in appearance of the mastocytoma granules is consistent with a variable degree of granule maturation. After disaggregation or periods of culture ranging from 2 days to 4 weeks, the mean granule diameters were 15% larger than those measured in the intact mastocytoma cells, though other morphological features remained unchanged. Although the cells retained their distinct morphological features for at least 4 weeks, some of their physiological responses were lost after 1 week in culture. Our study showed that dog mastocytomas can be a source of a large, relatively homogeneous population of cells that are useful for elucidating some of the structural and functional properties of mast cells.

Animals↗
PubMed1985

Hyperalimentation-associated jaundice: an example of a serum factor inducing cholestasis in rats.

A patient receiving total parenteral nutrition (TPN) at home following emergency resection of the small intestine was studied over a two year interval. Cholestatic jaundice developed after 6 months. A factor in serum was found to produce cholestatic changes in the bile flow of rats on intravenous infusion. Normal human serum and saline infusion did not produce this cholestasis. Endotoxin infusion in the rat produced a similar impairment in bile flow. The hypothesis was proposed that endotoxin might be an occult factor contributing to cholestasis in this case. An antiserum prepared to an endotoxin isolated from a sequestered E. coli infection in this patient, ameliorated the cholestatic effects of the patients' serum in rats. The possible role of endotoxin in the cholestasis of the TPN-induced jaundice in this patient is presented and discussed.

Aged↗
PubMed1985

Intermediate filaments in meningiomas.

The presence of intermediate filaments (IF) (diameter 10 nm) is a characteristic electron microscopic finding in the cytoplasm of meningioma cells. To identify these IF, immunohistochemical staining for cytokeratins and vimentin and two-dimensional (2-D) gel electrophoresis followed by immunoblot analysis were applied to a group of 16 meningiomas. Thirteen meningiomas were obtained directly from surgery and three came from an autopsy in which they were found in close proximity as discrete tumor masses. Except for the angioblastic type, all major histological variants were represented (nine transitional, four syncytial, and three fibroblastic). None of the meningiomas stained for epithelial or internal organ cytokeratins. With monoclonal antibodies, each of the meningiomas stained positively for vimentin. Two-D gels revealed vimentin and vimentin breakdown products as the only IF present; these findings were verified by immunoblots. The study concludes that vimentin is the IF present in fibroblastic, syncytial, and transitional meningiomas.

Cytoskeleton↗
PubMed1985

Colchicine effect on bile canalicular motility: long-term study using isolated cultured hepatocytes and time-lapse cinephotomicrography.

The effect of colchicine on spontaneous in vitro contractions of bile canaliculi was assessed using time-lapse cinephotomicrography. Colchicine 2.5 microM and/or taurocholate 5 microM were added to the culture medium. The experiment was long-term, lasting for 13 h. Frame-by-frame analysis revealed that colchicine, after a lag period of 4 h, suppressed the number of contractions over the remainder of the 13-h experimental period, even in the presence of taurocholate (p less than 0.001). The number of contractions per hour decreased in both the colchicine and combined colchicine-plus-taurocholate-treated groups compared to untreated and taurocholate-treated controls. These results do not necessarily mean that colchicine has an effect on the contractile process per se, since the contractions, when they occurred, appeared normal. It is likely that the canalicular motility events are related to bile secretion. The reduction in contractions after a lag period likely indicates that secretion is impaired, and hence the need for contractions is reduced. These results support the view that for normal canalicular bile secretory function, microtubules as well as a normal microfilament system are required.

Animals↗
PubMed1985

Characterization of purified dog mastocytoma cells. Autonomic membrane receptors and pharmacologic modulation of histamine release.

There is conflicting evidence as to which autonomic receptors mast cells possess and whether the receptors are capable of modulating mediator release. We have studied dog mastocytoma cells because they are available in large numbers in a relatively pure form, unlike normal dog mast cells. Mastocytoma nodules from a dog were excised and disaggregated with collagenase to provide a cell suspension of mastocytoma cells of greater than 92% purity. The presence of autonomic receptors was assessed by both radioligand binding assays and by evaluating pharmacologic modulation of mediator release. In the radioligand binding assays, beta-adrenergic receptors were estimated by [3H]dihydroalprenolol binding, alpha-adrenergic receptors by [3H]prazosin binding and cholinergic receptors by [3H]quinuclidinyl benzilate binding. Nonspecific binding was determined in each case by incubation in the presence of the specific antagonists propranolol, phentolamine, and atropine, respectively. The effect of autonomic agonists on immunologic and nonimmunologic histamine release was examined, using the beta-adrenergic agonists isoproterenol and terbutaline, the alpha-adrenergic agonist phenylephrine with and without propranolol, and the cholinergic agonist acetylcholine. Dose-response curves were constructed both for the autonomic agonists and the histamine-releasing agents. Results from the radioligand binding and the pharmacologic studies were concordant. These dog mastocytoma cells had a high density of beta-receptors (21,500 +/- 3,300; mean +/- SE beta-receptors/cell, n=5) of which the predominant subtype appeared to be beta2. No evidence was found for the presence of alpha-adrenergic or cholinergic receptors either by direct receptor binding or by their actions on histamine release.

Acetylcholine↗
PubMed1985

Cell motility of fetal hepatocytes in short-term culture.

The motility of freshly isolated fetal rat hepatocytes using time-lapse cinemicroscopy was documented and the fetal liver was stained by the DACH-HMM method for F-actin. This approach allowed direct correlation of cellular activity with the distribution of cytoplasmic actin filaments. The fetal liver cells were highly active, and showed ruffling, pseudopodia, and random forceful movements which caused the cells to pull apart from each other. The behavior of these cells differed markedly from that of adult liver cells which remain cohesive and show orderly contractions of bile canaliculi. Cytoplasmic actin in fetal hepatocytes lacked the predominantly pericanalicular distribution observed in adult cells. Random spontaneous cellular contraction and locomotion of fetal liver cells give way during maturation to orderly, forceful contractions of bile canaliculi in fully differentiated cells and is accompanied by a redistribution of the cellular actin. These finding collectively suggest a correlation between actin filament distribution, hepatocellular development, and functional maturation.

Actins↗
PubMed1985

Histochemical and immunohistochemical characterization of surgically resected and heterotransplanted Wilms' tumor.

Nine surgically resected Wilms' tumors (WIT) and nude mouse heterotransplants from one WIT were studied by histochemistry and immunohistochemistry. Histochemistry showed acid phosphatase in all cells, while alkaline phosphatase and gamma-glutamyl transpeptidase were present in only some tubules. Using immunohistochemistry, antibodies to the intermediate filaments cytokeratin and vimentin distinguished tubular epithelium and mesenchyme, respectively. WIT tubules were also identified using antibody against a structural component (epithelial membrane antigen) and a secretory product (uromucoid) associated with distal convoluted tubules of normal kidney. Basement membrane surrounding the tubules of WIT was demonstrated using antibody to type IV collagen plus laminin. Different blastema subpopulations were negative or stained positively with antibodies to cytokeratin and vimentin. Production of basement membrane by blastema was also shown. Fetal antigen expression in WIT was examined using the monoclonal PI 153/3 and J5 antibodies. The blastema and tubules of WIT were strongly stained by PI 153/3, which did not label normal adult kidney, and weakly stained by J5, which strongly labeled glomeruli and proximal convoluted tubules of normal kidney. These studies show that WIT blastema is heterogeneous in intermediate filament subtypes, while WIT tubules more closely resemble distal than proximal convoluted tubules of adult kidneys but also retain expression of fetal antigens.

Acid Phosphatase↗
PubMed1985

Relationship of histology of Wilms' tumor to growth characteristics of nude mouse heterotransplants.

Eighteen Wilms' tumors (WIT), including classical triphasic WIT (blastema, tubules, and mesenchyme) and WIT variants (blastema and tubules, monomorphous tubules, multiloculated cysts, rhabdomyomatous WIT, and clear cell sarcoma), were heterotransplanted in nude mice. Ten (56%) tumors grew and were serially passaged. With two exceptions, the histology of the surgically resected tumors and heterotransplants was found to be similar. Tumors showing a prominent blastema component grew rapidly, whereas those with tubular epithelial or mesenchymal differentiation grew more slowly. Tumors injected s.c. consisted almost entirely of blastema, while tumors injected i.p. consisted of blastema with large areas of tubular epithelium. These results demonstrate that nude mouse heterotransplants of WIT closely resemble the surgically resected tumors from which they derive, that growth rates of WIT heterotransplants depend on the identity of the tumor cells, and that differentiation of WIT heterotransplants can be modulated, depending on the route of administration of tumor cells.

Anaplasia↗
PubMed1985

Q-fever. The liver and bone marrow pathology.

Eighteen liver and seven bone marrow biopsies from 44 patients with clinically and serologically proven Q-fever seen during a recent outbreak were studied. Highly distinctive fibrin-ring granulomas were found in seven liver and four bone marrow specimens. Lipid or nonspecific granulomas often containing neutrophils and variable numbers of giant cells were noted in 13 livers and seven bone marrows. A wide variety of nongranulomatous histological changes, frequently including steatosis and nonspecific "reactive" hepatitis, were seen in the liver biopsies. Identifiable rickettsiae were not present in tissue sections studied by microbiologic stains or electron microscopy. The histological response pattern to Coxiella infection is varied, and Q-fever should always enter the differential diagnosis of a granulomatous disease encountered in liver and bone marrow specimens.

Animals↗
PubMed1985

Hilar biliary plexus in human liver. A comparative study of the intrahepatic bile ducts in man and animals.

A comparative study of the hepatic bile ducts of man and laboratory animals was made by means of scanning electron microscopy of biliary tract casts. In man, the large intrahepatic bile ducts at the hilum have many irregular side branches and pouches which are all situated in one plane corresponding anatomically to the transverse fissure (porta hepatis). At the bifurcation, some of the side branches from two or three bile ducts communicate with each other. The anastomosing plexus so formed provides communications between the main bile ducts. Bile ducts of the rhesus monkey show a similar but less well developed structure. In the pig, many pouches are observed around not only large but also small bile ducts. No such structures are observed in dog, guinea pig, or rabbit bile ducts. These irregular side branches and pouches correspond to the "vasa aberrantia" and "parietal sacculi" described by L. S. Beale (The Liver. Lecture on the Principles and Practice of Medicine, p 47. London, Churchill, 1889), and they may store and modify bile. The plexus described in man in this report may provide an anatomical basis for incomplete biliary obstruction without cholestasis. A role in biliary atresia and in Caroli's disease is also raised.

Animals↗
PubMed1985

Coordination of the contractile activity of bile canaliculi. Evidence from spontaneous contractions in vitro.

Rat hepatocytes, when isolated and maintained in primary culture, are capable of producing forceful contractions of their bile canaliculi, with contractions occurring on a regular basis once every 5.5 minutes. To determine whether the contraction of one bile canaliculus affected the contraction of a neighboring canaliculus, cinephotomicrographic studies of pairs of contiguous canaliculi were undertaken. The activity of 10 pairs of contiguous canaliculi, and 10 pairs of noncontiguous canaliculi which served as a control group, was recorded for a period of 12.5 hours at the rate of 1 frame every 15 seconds. Using frame-by-frame analysis of this period of observation, we determined the time of contraction of each of the canaliculi in the pairs. Cross-correlations were obtained for the contraction times of each of the 10 pairs of contiguous canaliculi and 10 control pairs. A peak in activity was found, with that peak occurring five frames or 75 seconds from the midline, whereas the noncontiguous controls showed no correlation in contractile activity. This finding indicates that, when one bile canaliculus contracts, a neighboring canaliculus is likely to contract after an interval of 1.25 minutes. That there is coordination of contractile activity of bile canaliculi suggests that, within the intact liver lobule, ordered motility function of the bile canaliculi may facilitate bile flow.

Animals↗
PubMed1985

Coordination of the contractile activity of bile canaliculi. Evidence from calcium microinjection of triplet hepatocytes.

The discovery that bile canaliculi are capable of spontaneous contractile activity has led to their use in the investigation of the physiology of the liver cell. The contraction of a bile canaliculus is dependent on the network of actin, which is found in the pericanalicular region of the hepatocyte, and agents that inhibit actin filaments interfere with canalicular contraction. Injection of calcium directly into the cytoplasm of one hepatocyte of a cell pair results in contraction. Injection of calcium directly into the cytoplasm of one hepatocyte of a cell pair results in contraction of the canaliculus. To determine whether the contractile activity of adjacent bile canaliculi was coordinated, calcium was injected into one cell of a group of three hepatocytes that formed two neighboring bile canaliculi. Calcium microinjection resulted in contraction of the bile canaliculus contiguous with the microinjected cell and was followed by a contraction of the second, adjacent canaliculus. These secondary contractions occurred after an interval of approximately 45 seconds. The finding that bile canalicular contractions are coordinated with contractions occurring in a sequential fashion supports the hypothesis that, within the liver lobule, transport of bile within the canalicular network results from the coordinated contractions of the canaliculi.

Animals↗