Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The microcirculation contains mononuclear phagocytes, with features characteristic of macrophages, adhered to luminal capillary surfaces by intercellular adhesion plaques. These pulmonary intravascular macrophages may play an important role in regulating lung vascular tone and capillary permeability, and may modulate capillary endothelial cell growth and replication by the secretion of soluble mediators (i.e., arachidonate metabolites, cytokines). This study describes a technique which utilizes in situ lung perfusion to remove intravascular macrophages in large numbers from the microcirculation of porcine lung (n = 26). This technique yielded 3.8 +/- 0.5 x 10(8) (mean +/- SEM) mononuclear cells which were highly phagocytic toward particulate carbon (phagocytic index, 80 +/- 6%). Harvested mononuclear phagocytes reestablished intercellular adhesion plaques when placed on small vessel porcine pulmonary artery endothelial cell monolayers and exhibited histochemical characteristics typical of monocyte/macrophage lineage cells. Mononuclear cells obtained from lung microcirculation displayed size heterogeneity varying from 10.4 to 16.5 microns in diameter. Both large and small cell populations phagocytosed particulate carbon. Morphometric studies performed on collagenase-treated lung demonstrated that in situ perfusion removed significant numbers of intravascular macrophages in lung capillaries. The technique described permits the rapid removal of anchored mononuclear phagocytes from lung capillaries with minimal postmortem delay.
 ...
PMID:In situ pulmonary vascular perfusion for improved recovery of pulmonary intravascular macrophages. 164 74

Human gastric mucosal cells were isolated by digestion of fundic biopsies with pronase and collagenase. The mean value of gastric cells per milligram biopsy specimen +/- SEM was 59,000 +/- 4,300 (n = 31) with a viability of 90 +/- 5%. With the cell yield of 1 patient a series of approximately 70-80 cyclic AMP measurements was possible. Histamine stimulated intracellular cyclic AMP production with an EC50 value of 35 +/- 25 mumol/l (SEM; n = 4). In the presence of 100 mumol/l histamine the Ki values (mumol/l) for the histamine H2 receptor antagonists averaged 1.45 (cimetidine), 0.10 (ranitidine), and 0.02 (famotidine). No significant inhibition of histamine-induced cyclic AMP production was obtained with the histamine H1 receptor antagonist triprolidine. With the new method histamine-induced cyclic AMP production can be measured in intact human gastric mucosal cells from fundic biopsy samples.
 ...
PMID:A method to assess histamine-induced cyclic AMP production in isolated gastric mucosal cells from human biopsies. 168 55

Cytokines, interleukin-1 (IL-1), tumor necrosis factor alpha, and the neurotransmitter, substance P, have been implicated in the pathogenesis of arthritis because they stimulate synovial cells to secrete prostaglandin E2 and collagenase in vitro. We investigated in vivo changes in intraarticular substance P and the degradation of cartilage proteoglycan in response to intraarticular cytokine injections in rabbits. Twenty-four hours after a single injection of 10 ng, 30 ng, or 100 ng of recombinant human IL-1 alpha (rHuIL-1 alpha) per joint, the mean +/- SEM levels of substance P detected in the cell-free joint lavage fluid were 250 +/- 67 fmoles, 480 +/- 60 fmoles, and 530 +/- 130 fmoles (n = 4-5), respectively. The level of substance P in the contralateral knees injected with diluent was 58 +/- 8 fmoles (n = 12). The level of substance P had increased by 2 hours after IL-1 injection and remained elevated in the joint 48 hours after injection. Cytokine-induced proteoglycan depletion was also time- and dose-dependent. Proteoglycan concentrations in articular cartilage dissected from the weight-bearing condyles were calculated as the ratio of sulfated glycosaminoglycan measured using 1,9-dimethylmethylene blue: hydroxyproline. After 48 hours, 10 ng, 30 ng, or 100 ng of rHuIL-1 alpha per joint decreased proteoglycan levels by 9 +/- 4%, 14 +/- 4%, and 21 +/- 3% (n = 8), respectively. Likewise, the injection of recombinant human tumor necrosis factor alpha induced depletion of intraarticular substance P and cartilage proteoglycan.
 ...
PMID:Elevated substance P and accelerated cartilage degradation in rabbit knees injected with interleukin-1 and tumor necrosis factor. 169 99

Morphological heterogeneity has not been documented for cultured endothelial cells isolated from the microvascular bed of any organ. As the corpus luteum depends on a rich microvascularization, endothelial cells were dislodged from developing corpora lutea by mechanical dissection followed either by collagenase digestion or by no digestion. Cell separation was carried out by Percoll density centrifugation. Although the yield of intact cells was higher with collagenase treatment than without, successful endothelial cell cultures were only established when cells remained untreated. Viewed by light microscopy after an average lag phase of 10 days, five different phenotypes of endothelial cells were found under similar simple culture conditions: isomorphic epithelioid, polymorphic epithelioid, spindle-shaped, round, and phase-dense phenotypes. Monolayers appeared within 2-4 weeks. After an additional period of 2-4 weeks, tubular forms with a specific pattern were noted for types 1-3, the so-called pseudotubular forms for type 4, and none for type 5. Cell types differed in their cytochemical and immunocytochemical responses. Examined by SEM, type 1 displayed a more conspicuous surface anatomy than type 2. Types 3-5 demonstrated striking cell processes that were characteristic of each type. Tubular forms of types 1 and 2 showed cell borders and a marked increase in surface specializations, whereas tubular forms of type 3 lacked detectable cell borders in the absence of a striking surface anatomy. Pseudotubular forms of type 4 developed no particular spatial organization. Thus, for the first time, morphological evidence is provided that different endothelial cell types are obtained from diverse segments of the microvascular bed.
 ...
PMID:Different phenotypes of cultured microvessel endothelial cells obtained from bovine corpus luteum. Study by light microscopy and by scanning electron microscopy (SEM). 169 23

As part of an ongoing investigation of human mast cell heterogeneity, we have isolated, partially purified, and characterized the uterine mast cell and compared it with mast cells isolated from other organs. The average histamine content of myometrium and leiomyofibroma obtained from hysterectomies was 2.1 +/- 0.3 (mean +/- SEM) microgram/g of tissue (n = 10), and the histamine content of the two tissues did not differ significantly. A mild collagenase, hyaluronidase, and DNase digestion was used to disperse the uterine mast cells, with an average yield of 9.5% (range, 0 to 21%). The average histamine/uterine mast cell was 2.1 +/- 0.2 pg (n = 3), and 61 +/- 7% (n= 3) of the uterine mast cells survived overnight culture. Early purification efforts with Percoll gradients have yielded up to 80% pure uterine mast cells, with an average of 27 +/- 10% (n = 5). Uterine mast cells released histamine in response to the secretogogues anti-IgE and A23187 but did not respond to substance P or to the basophil secretogogues FMLP, C5a, and 12-O-tetradecanoylphorbol-13-acetate. After 1 microgram/ml anti-IgE stimulation, the uterine mast cell appeared to make significant quantities of PGD2 (89 +/- 26 ng/10(6) cells, n = 6) (p less than 0.05), as assayed by RIA. Simultaneously, leukotriene C4 release was 45 +/- 15 ng/10(6) cells, (n = 6) (p less than 0.05), as assayed by RIA. Combined gas-chromatography mass spectroscopy analysis of anti-IgE-stimulated cell supernatants confirmed the production of PGD2. In pharmacologic studies, isobutyl-methylxanthine and isoproterenol blocked anti-IgE-induced histamine release. The uterine mast cell is similar to the lung mast cell in terms of response to secretogogues and release of arachidonic acid metabolites. Ultrastructurally, the uterine mast cell contains scroll granules, crystal granules, combined granules, homogeneously dense granules, and large lipid bodies, many with focal lucencies within them. Particle granules, most frequently present in gut mast cells of mucosal origin, were absent from uterine mast cells. Although certain features are analogous to the ultrastructure of skin or lung mast cells, the combination of structures is distinctive for uterine mast cells.
 ...
PMID:Human uterine mast cells. Isolation, purification, characterization, ultrastructure, and pharmacology. 171 65

To evaluate the potential of utilizing porcine islet tissue as an alternative to human islet tissue for transplantation, we developed a method for the isolation of large amounts of highly purified porcine islets, and assessed the in vitro and in vivo function of the isolated islets after 1, 4, and 7 days of culture. The pancreatic duct of the splenic lobe was cannulated and distended by injection of Hanks' balanced salt solution containing 1.5 mg/ml collagenase. The pancreas was then processed by a modification of the automated digestion-filtration method developed in this laboratory, and with purification accomplished by Euro-Ficoll gradients (dialyzed Ficoll in Eurocollins solution), consisting of two layers of 1.108 and 1.091 g/cm3 density, topped with a layer of HBSS. The postpurification yield was 5203 +/- 645 (mean +/- SEM) islets per gram of pancreas with a number of islet equivalents (IE) per gram pancreas (islet equivalence: 150-microns-sized islets) of 3551 +/- 305, and a volume of 6.27 +/- 1.7 mm3 islet tissue per gram of pancreas. The islet purity exceeded 90%. Overnight-cultured, perifused porcine islets released 53.1 +/- 8.2 pM insulin/200 IE at 3.3 mM glucose, and 114.9 +/- 25.4 pM insulin/200 IE at 16.7 mM glucose (P less than 0.001 vs. basal output). When theophylline was added, insulin secretion increased to 264.2 +/- 63.2 pM/200 IE (P less than 0.001 vs. basal secretion and P less than 0.005 vs. secretion at 16.7 mM glucose). After 4 days of culture, the islets still responded to secretagogues. The functional integrity of the isolated islets was confirmed by reversal of diabetes in aL3T4 antibody-treated C57B/B6 diabetic mice: normoglycemia was promptly restored by transplanting 1000 overnight- or 7-day-cultured (24 degrees C) islets under the kidney capsule. These results suggest that continued improvements of porcine islet isolation and culture could permit the use of porcine islets in immunoalteration and immunoisolation studies that may lead to eventual human transplantation.
 ...
PMID:Automated large-scale isolation, in vitro function and xenotransplantation of porcine islets of Langerhans. 187 91

In the present study, increasing amounts of the anti-estrogen 1-(p-2-diethylaminoethoxyphenyl)-1-phenyl-2-p-methoxyphenoletha nol (MER-25) were administered to pregnant baboons (Papio anubis) to block the action of endogenous estrogen and to determine effect on placental low-density lipoprotein (LDL) uptake. Pregnant baboons were untreated (n = 8) or received MER-25 orally at a dosage of 25 (n = 10), 50 (n = 8), or 75 (n = 4) mg/kg BW daily on Days 140-170 of gestation (term = 184 days). Placentas were removed on Day 170 of gestation and villous tissue was dispersed with 0.1% collagenase. Placental cells (10(6] were incubated in Medium 199 for 12 h at 37 degrees C with increasing amounts of 125I-LDL, with or without a 100-fold excess of unlabeled baboon LDL. Mean (+/- SEM) placental uptake (ng/micrograms cell protein) of 125I-LDL was 55% (6.4 +/- 1.0), 75% (3.6 +/- 0.7), and 81% (2.7 +/- 0.2) lower (p less than 0.001) in baboons that received MER-25 in doses of 25, 50, and 75 mg/kg BW, respectively, than in untreated baboons (14.2 +/- 1.3 ng/micrograms cell protein). Maximal effect occurred with 50 mg MER-25, because LDL uptake was not further decreased with greater levels of MER-25. Dissociation constants for placental LDL uptake, as determined by Scatchard analysis, were unaltered by anti-estrogen treatment. The amount of 125I-LDL degradation by placental cells of untreated and MER-25-treated baboons was proportional to LDL uptake.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Regulation of placental low-density lipoprotein uptake in baboons by estrogen: dose-dependent effects of the anti-estrogen ethamoxytriphetol (MER-25). 187 35

Previous studies have shown that the yield and viability of islets obtained from human or large mammal pancreas depends upon techniques used for islet isolation and upon factors that affect the quality of the donor pancreas. In the present studies, the efficacy of collagenase digestion by ductal perfusion or automated techniques was compared in a canine model of purified islet isolation. The ductal perfusion technique was then developed for human pancreas which was excised before (n = 8) or after (n = 8) multiple organ procurement and without in situ arterial perfusion of hypothermic preservation solution or significant cold storage. Studies with canine pancreas showed that ductal perfusion yielded 2.0 +/- 0.7 microL of islets/g of pancreas and when combined with automated digestion, yields improved to 3.6 +/- 0.8 microL/g (versus perfusion alone, not significant). The yield and viability of human islets was improved when the pancreas was excised before procurement of other donor organs. Results of islet isolation from eight consecutive human pancreases procured in this manner revealed a total yield of 355.2 +/- 44 x 10(3) islets, corresponding to 5345 +/- 600 islets/g (+/- SEM, mean islet diameter 150 microns). Six of eight Ficoll purification attempts succeeded, yielding 186.6 +/- 31 x 10(3) islets of purity ranging from 45-60%. Perifusion with glucose elicited biphasic insulin secretion with a three-fold rise. Islets from two of the isolations were utilized to initiate a clinical trial of islet transplantation in insulin-dependent diabetes mellitus.
 ...
PMID:Isolation of purified large mammal and human islets of Langerhans. 196 80

A simple procedure which provides a large yield of isolated ferret ventricular myocytes is described. The enzymatic dissociation was performed by perfusion of the whole heart with the "Langendorff method" at 37 degrees C, without an incubation period. Special attention was given to the period of perfusion with Ca-free or low-calcium containing solutions and to the proportion of both collagenase and elastase used. The viability and calcium tolerance of the isolated cells were tested by ultrastructural and electrophysiological studies. Photo-microscopy showed that 60 to 80% of the isolated cells had an elongated shape (18 microns in diameter, 150 microns in length) and did not beat spontaneously in normal Tyrode solution. The morphological and ultrastructural integrity of these cells was shown in SEM by their smooth surface with regularly spaced T-tubule openings and in TEM by the regular distribution of the transverse tubular system, mitochondrium and sarcomeres. Using the whole-cell patch-clamp technique, they had a resting membrane potential of -72 mV, two types ("Purkinje like" and "ventricular like") of action potentials could be elicited and they were correctly affected by well-known modulators of calcium channels. This technique was successfully applied to the rat heart and could be used for heart dissociation of small mammals. It can simultaneously provide isolated cells of different regions of the heart and can be easily and routinely used by any investigator.
 ...
PMID:An efficient isolation procedure of Ca-tolerant ventricular myocytes from ferret heart for applications in electrophysiological studies. 210 19

Regulation of urea transport by vasopressin in inner medullary collecting duct (IMCD) cells is thought to be important for the urinary concentrating mechanism. Isolated tubule perfusion studies suggest the existence of a saturable urea carrier. We have measured 14C-urea efflux in IMCD cells which were freshly isolated and grown in primary culture. Cells were isolated from rat papilla by collagenase digestion and hypotonic shock. In suspended cells, 14C-urea efflux (Jurea) from loaded cells was exponential with time constant 59 +/- 3 sec (SEM, n = 6, 23 degrees C). Jurea had an activation energy of 4.1 kcal/mole and was inhibited 42 +/- 7% by 0.25 mM phloretin and 30-40% by the high affinity urea analogues dimethylurea and phenylurea. Jurea was increased 40-60% by addition of vasopressin (10(-8) M) or 8-bromo-cAMP (1 mM); stimulated Jurea was inhibited 55 +/- 8% by the kinase A inhibitor H-8. Phorbol esters and epidermal growth factor did not alter Jurea. IMCD cells grown in primary culture were homogeneous in appearance with greater than fivefold stimulation of cAMP by vasopressin. The exponential time constant for urea efflux was 610 +/- 20 sec (n = 3). Jurea was not altered by vasopressin, cAMP or phloretin. Another function of in vivo IMCD cells, vasopressin-dependent formation of endosomes containing water channels, was absent in the cultured cells. These results demonstrate presence of a urea transporter on suspended IMCD cells which is activated by cAMP and inhibited by phloretin and urea analogues. The urea transporter and its regulation by cAMP, and cAMP-dependent apical membrane endocytosis, are lost after growth in primary culture.
 ...
PMID:Urea transport in freshly isolated and cultured cells from rat inner medullary collecting duct. 217 46


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>