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[Modified radical lymph node dissection in the treatment of gastric cancer invading the gastric serosa].

The improvement in prognosis for patients with advanced gastric cancer may be attributable to the success of the extensive lymph node dissection and adjuvant anticancer chemotherapy. In the present study, however, we found that the postoperative long-term prognosis for patients with gastric cancer invading the gastric serosa was not improved even by more extensive lymph node removal (R3-removal) than secondary lymph node removal (R2-removal). This difference indicates that serosal invasion by cancer, which is a source of exfoliating cancer cells and is closely related to peritoneal metastasis, is another factor influencing the prognosis of gastric cancer patients. Actually, in patients with gastric cancer who had serosal invasion, free cancer cells were frequently detected in the peritoneal cavity by means of pelvic lavage. We introduced continuous hyperthermic peritoneal perfusion (CHPP) with an anticancer drug as a prophylactic treatment for peritoneal recurrence after surgery for gastric cancer. In the randomized control study, the cumulative 5-year survival rate of patients in the CHPP group was better than that of the control group, although there was no significant difference. Based on the above, we suggest that in gastric cancer with serosal invasion, selective removal of Group 3 lymph nodes according to the location of the primary cancer lesion (modified radical lymph node dissection) and prophylactic treatment for peritoneal metastasis promise better outcome.

Antineoplastic Agents↗

Curschmann's spirals in pleural and peritoneal fluids. Report of 12 cases.

A limited prospective study of 334 peritoneal and pleural fluids demonstrated Curschmann's spirals in 12 specimens, a prevalence of 1 in 28 cases. Nine of these 12 specimens were peritoneal washings, 2 specimens were pleural fluids, and 1 specimen was a peritoneal dialysis fluid. The fluids came from nine women and three men. Both pleural fluids were from men (one with a history of lung adenocarcinoma and one with probable collagen vascular disease). The peritoneal dialysis fluid was from a man with renal failure. Seven of the nine women with peritoneal washing specimens had gynecologic cancer; only one had evidence of serosal involvement by neoplasm at the time of the peritoneal washing. Tissue, including serosal surfaces, was available for examination in 10 of the 12 cases. The study indicates that Curschmann's spirals are a relatively common finding in peritoneal and pleural fluids, particularly in peritoneal washings. Mucin-producing epithelium or involvement of serosa by malignant neoplasm is not necessary for the phenomenon to take place. The feature common to all the cases in which tissue was available for review was the presence of myxoid degenerative changes of the serosal and subserosal fibrous connective tissue.

Adenocarcinoma↗

[Preoperative cancer chemotherapy for gastric cancer].

Preoperative cancer chemotherapy for gastric cancer was reviewed with special emphasis on histologic findings and survival. Preoperative chemotherapy with intravenous, split administration of MMC 40 mg caused considerable damage to "micro-solitary metastatic foci" in metastatic lymph nodes. In view of the lipid-adsorbing ability of the lymphatic stream, emulsified 5-FU was used orally in 182 patients with gastric cancer; histologic findings revealed that the emulsified 5-FU enhanced the antitumor efficacy for metastatic lymph nodes as well as the primary lesion. However, the 5-year survival rate for gastric cancer patients undergoing preoperative emulsified 5-FU therapy did not differ from the control, with only the exception of patients with Stage III gastric cancer. On the other hand, combined therapy involving preoperative intra-arterial infusion and surgery was carried out in 62 patients with gastric cancer. These preoperative treatments using MMC, 5-FU, VLB, MTX and/or cytosine arabinoside entailed continuous infusion for 15 to 20 hours; the histologic changes observed revealed marked antitumor effects on the primary focus as well as metastatic lymph nodes. The five-year survival rate for the 62 patients was compared with that for 99 patients with gastric cancer in the corresponding period. The survival rate was analyzed based on the degree of serosal invasion. The overall survivals in the 62 patients were higher than those in the controls for the first 3 years. At 4 to 5 years, the survival rates for both the treated and control groups were approximately equal. In patients without serosal invasion, the survival rates were higher in treated cases than in the controls for the first 2 years. Thirty-nine patients with serosal invasion had significantly higher survival rates than the controls for the first 3 years. The survival rates for the treated patients with cancerous infiltration of ther organs were about the same as those for the corresponding control patients.

Administration, Oral↗

Enteric neural pathways inhibitory to rabbit duodenal serotonin release.

Previous studies have shown that adrenergic and cholinergic neural pathways mediate duodenal serotonin (5-HT) release from the mucosal surface after a luminal acid stimulus. To examine the overall neural contribution to 5-HT release, we studied the effects of tetrodotoxin (TTX), a nerve-conduction blocker, added to mucosal and/or serosal surfaces of rabbit duodenal mucosa in a modified Ussing chamber at both neutral and acid (pH 5) luminal pH. A specific radioimmunoassay was used to measure 5-HT. TTX (2 X 10(-7) M) increased mucosal 5-HT release significantly at luminal pH 7.4 and 5 when it was added to both mucosal and serosal surfaces (2.7- and 1.9-fold at pH 7.4 and pH 5, respectively; p less than 0.05 for each) or when it was added to the serosal surface only (3.4- and 1.8-fold; p less than 0.02 and p less than 0.01, respectively). TTX added only to the mucosal surface, however, reduced 5-HT release by 48.5% at pH 5 (p less than 0.01) and had no effect at pH 7.4. Since adenosine triphosphate (ATP) and vasoactive intestinal polypeptide are the two proposed mediators of a nonadrenergic, noncholinergic inhibitory neural system, we studied the effects of each on mucosal 5-HT release. While vasoactive intestinal polypeptide had no significant effect at either pH, ATP (10(-7)M) reduced acid-stimulated 5-HT release by approximately 50% (p less than 0.02). We conclude that a nonadrenergic, noncholinergic neural pathway that is inhibitory to mucosal 5-HT release resides primarily on the basal surface of mucosal cells. ATP is the most likely neurotransmitter involved in this response.

Adenosine Triphosphate↗

[Peptide transport and peptidase localization in the small intestine of chickens].

The mechanism of peptide transport was studied in vitro in the small intestine of chicks and accumulating preparations of mucosa using glycyl-1-tryptophan. A special criterion was proposed to differentiate the processes of intracellular and membrane hydrolysis of dipeptide basing on the analysis of transport intensity of amino acids released into the serosal solution after hydrolysis of dipeptide. 1-tryptophan released at hydrolysis was transported considerably more slowly than free amino acid. 1-tryptophan from the mixture with glycyne demonstrated the highest transport intensity in serosal solution as well as the highest accumulation in the mucosa cells from all forms of 1-tryptophan. At the same time the peptide form of glycyne was transported with the same intensity as that from the mixture with 1-tryptophan. According to the criterion applied it is supposed that unequal levels of 1-tryptophan and glycyne in the serosal solution prove the membrane hydrolysis of glycyne-1-tryptophan during ist transport in enterocytes.

Animals↗

Effect of lanthanum on urinary acidification and sodium transport by the turtle and toad bladder.

Lanthanum has been extensively used to evaluate the role of extracellular and membrane-bound calcium on several aspects of cell function. In the present study we evaluated the effect of mucosal or serosal addition of lanthanum on Na and H+ transport by the turtle bladder, in vitro, to gain insight concerning the role of calcium on these processes. Mucosal addition of lanthanum was associated with a decrease in Na transport and H+ secretion. The inhibition was of rapid onset, achieving a maximal inhibition at 10(-3) M for H+ secretion and 5 X 10(-4) for Na transport. The effect was rapidly and totally reversible with the removal of lanthanum. The mucosal effect of lanthanum addition was observed only at pH 7.4 for H+ secretion and at pH 7.4, 6.4, and 5.4 for Na transport. Agents capable of 'screening' the negative change of membrane proteins, such as cadmium or zinc, could neither elicit nor prevent the effect of lanthanum on H+ secretion. The effect of serosal addition of lanthanum on H+ or Na transport was different from that observed with mucosal addition; it was of slow onset, smaller magnitude, partially reversible, and only elicited by high concentrations (10 mM) of lanthanum. Serosal addition of lanthanum caused an early increase and a late decrease in radioactive calcium efflux. Mucosal addition of lanthanum caused an increase in calcium efflux. The data demonstrate that lanthanum inhibits Na and H+ transport in the turtle bladder and suggest that the mechanism of action of lanthanum is the result of either displacement of membrane-bound calcium or altered cell membrane permeability to calcium.

Animals↗

Alkali secretion by isolated rabbit gastric mucosa: effects of non-steroidal anti-inflammatory drugs and prostaglandins.

The effects of aspirin, indomethacin and prostaglandins E2 and F2 alpha on the secretory and electrical activity of isolated rabbit gastric mucosa have been studied. Serosal side application of indomethacin (10(-5) M) or aspirin (3 X 10(-3) M) inhibited alkali secretion by fundic mucosa (mean +/- SE: 0.55 +/- 0.06 to 0.12 +/- 0.06 mumol X cm-2 X h-1, n = 6, p less than 0.01 and 0.28 +/- 0.06 to 0.11 +/- 0.03 mumol X cm-2 X h-1, n = 7, p less than 0.02 respectively) and antral mucosa (0.80 +/- 0.03 to 0.53 +/- 0.21 mumol X cm-2 X h-1, n = 5, p less than 0.01 and 0.75 +/- 0.23 to 0.47 +/- 0.20 mumol X cm-2 X h-1, n = 8, p less than 0.01 respectively). Mucosal and serosal side application of prostaglandin E2 or F2 alpha (10(-10) to 10(-4) M) had no effect on gastric alkali secretion. Serosal side 16,16 dimethyl E2 (10(-6) M) stimulated alkali secretion by fundic mucosa (0.90 +/- 0.20 to 1.50 +/- 0.30 mumol X cm-2 X h-1, n = 6, p less than 0.01) and abolished the inhibition of alkali production caused by indomethacin in fundic and antral mucosae. Inhibition of alkali secretion by aspirin was not modified by 16,16 dimethyl E2 pretreatment. The findings suggest that mucosal damage by aspirin and indomethacin may be mediated by inhibition of alkali secretion and that the protective action of various prostaglandins are only partly related to effects on this secretion.

Alkalies↗

[Effect of N-ethylmaleimide, introduced in to the serous fluid, on the active transport of sodium through the skin of Rana esculenta].

An SH reactive agent, N-ethylmaleimide (NEM), if introduced in the serosal bath (10(-4) M), stimulates the short circuit current (SCC) across the frog skin. This effect is due to an increase of Na active transport, because is inhibited by ouabain (10(-4) M). A stimulatory action on Cl- or HCO3- secretion can be ruled out because the rise in SCC occurs also in the absence of Cl- or HCO3-. It is known that NEM inhibits the ADH action by forming covalent bounds with SH groups of ADH membrane receptors (1). Thus it is possible that this binding should mimic the ADH action on SCC. In order to test this hypothesis, we studied the effect of serosal NEM on SCC both in the absence and in the presence of I midazol (20 mM), an activator of the cyclic AMP phosphodiesterase. Imidazol treatment decreases the effect of NEM on SCC. Thus we conclude that NEM serosal treatment is able to mimic some ADH effects, by using the same ways of the ormone action.

Animals↗

Arachidonic acid stimulates short-circuit current in the isolated toad urinary bladder.

The effects of the prostaglandin (PG) precursors 5,8,11,14-eicosatetraenoic acid (arachidonic acid) and 8,11,14-eicosatrienoic acid (dihomo-gamma-linolenic acid) on short-circuit current (SCC) were assessed in the isolated toad urinary bladder. Arachidonic acid added to the serosal bathing media increased SCC and immunoreactive PGE2 (iPGE2) synthesis in a dose-related manner. Pretreatment with eicosatetraynoic acid (50 micrometer), a prostaglandin synthetase inhibitor, completely blocked the arachidonic acid-induced increase in SCC and significantly reduced iPGE2 synthesis (P less than .025, n = 9). Eicosatrienoic acid (100 micrometer) was equieffective with arachidonic acid in increasing SCC and iPGE1 synthesis. Addition of arachidonic acid (100 micrometer) to the mucosal bathing media produced no significant increase in SCC and only increased iPGE2 synthesis from 0.03 +/- 0.01 pmol/min (n = 5) to 0.31 +/- 0.03 pmol/min, a level not different from the serosal basal rate of iPGE synthesis (0.21 +/- 0.16 pmol/min, n = 5). PGE1 (1 micrometer) added to the serosal media significantly increased SCC reaching a maximum increase of 157 +/- 43% (P less than .025, n = 6) by 30 min whereas addition to the mucosal media resulted in a delayed (60 min) and lesser maximum increase (59 +/- 19%, P less than .02, n = 6). It is concluded that prostaglandin precursors increase SCC and PGE synthesis in the isolated toad urinary bladder. However, the present data do not support PGE as the metabolite responsible for the increase in SCC.

8,11,14-Eicosatrienoic Acid↗

Blastokinesis in embryos of the bug, Pyrrhocoris apterus. A light and electron microscopic study 1. Normal blastokinesis.

In the bug, Pyrrhocoris apterus, blastokinesis (a reversal of the position of the embryo within the egg) is seen to involve contraction of the serosa that is attached to the embryo's head. As the serosal cells change from squamous to columnar in the course of blastokinesis, a dense zone of microfilaments appears just under the apical surface. Many apical protrusions develop above this zone. After the embryo is in its final position the zone disappears and later the cells degenerate. Laterally, the serosal cells are connected by belt desmosomes, septate junctions and gap junctions. As blastokinesis progresses, more lateral surface is recruited below them from the original basal surface. Microtubules running parallel to the plasma membrane are seen near the apical microfilaments and along other surfaces of the cell. Secretory granules are evident both within serosal cells and along the apical surface, probably providing a lubricant for movement against the chorion. Yolk cells are common basal to the serosa, possibly mobilizing nutrients for it. This study of blastokinesis in Pyrrhocoris provides a dramatic example of cell shape change that is correlated with the appearance of microfilaments. In its details blastokinesis is comparable to morphogenetic events such as amphibian neural tube formation and ascidian metamorphosis.

Animals↗

Iron absorption in the everted chicken intestine.

Everted chicken intestines from 2-4 week old males were prepared according to the Wilson and Wiseman technique. The sacs were kept in a glucose ionic balanced solution, containing different cold iron concentrations (0.02; 0.01; 0.5; 1 mM Fe) and 59Fe was added as a tracer. The mucosal iron uptake and the iron transfer in the serosal fluid were determined at different intervals (1; 5; 10; 20 min) and in three main segments. The viability of the intestinal sacs was controlled by manometric O2 evaluation. The iron mucosal uptake was proportional to the iron concentration but the serosal iron transfer presented a saturation level, with similar behavior for both the duodenum and the jejunum. Iron transfer decreased with time and this could suggest a serosal to mucosal reflux. No effect was noted from the presence of metabolic inhibitors (0.01 mM sodium azide or 0.5-2 mM 2-4-dinitrophenol).

Animals↗

Asparagine stimulates piglet intestinal Cl- secretion by a mechanism requiring a submucosal glutamate receptor and nitric oxide.

Amino acids are potential components of oral rehydration solutions for infants, which could combine with glucose to further stimulate intestinal Na+ and water absorption. L-Glutamine, the principal fuel of the intestine, stimulates neutral NaCl absorption and enhances enterocyte DNA synthesis, but is unstable in solution. L-Asparagine (ASN), a more stable amino acid with similar structure to L-glutamine, also stimulates enterocyte proliferation. We determined the effects of ASN on electrolyte transport across piglet jejunum in Ussing chambers. Mucosal but not serosal ASN produced electrogenic Cl- secretion (delta JClnet = -1.8 +/- 0.3 microEq/cm2.hr-1). ASN, when added at 0.1 to 30 mM, increased short-circuit current in a dose-dependent manner with a K1/2 of approximately 5 mM and maximal effect at approximately 10 mM. The stimulation of Cl- secretion by ASN was blocked by pretreatment with serosal tetrodotoxin and bumetanide and was inhibited by preincubation with capsaicin (8-methyl-N-vanillyl-6-nonenamide) or substance P. Inhibition of nitric oxide synthesis with the structural analog of L-arginine, NG-monomethyl-L-arginine, reduced ASN-stimulated secretion by > 70%. Additionally, serosal 6-cyanonitro-quinoxaline 2-3-dione, which is a nonspecific blocker of neural non-N-methyl D-aspartate (NMDA) glutamate receptors, fully inhibited the ASN response (IC50 = 10(-6) M). Inhibition was specific for neurally mediated secretion. We found no inhibition of ASN-stimulated secretion by atropine, ketanserin, indomethacin or L-2-amino-5-phosphonovalerate (specific for NMDA receptors). When compared to ASN, L-glutamate was a weaker stimulator of jejunal Cl- secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Role of Na+ in the asymmetric paracellular transport of 4-phenylazobenzyloxycarbonyl-L-Pro-L-Leu-Gly-L-Pro-D-Arg across rabbit colonic segments and Caco-2 cell monolayers.

This study was conducted to demonstrate that Na+ played a role in the paracellular transport of 4-phenylazobenzyloxycarbonyl-L-Pro-L-Leu-Gly-L-Pro-D-Arg (Pz-peptide), a hydrophilic proline-containing pentapeptide, across the rabbit colonic mucosa and Caco-2 cell monolayers. Over the 1 to 5 mM concentration range, Pz-peptide transport was 25 to 180 times greater from the mucosal-to-serosal than from the opposite direction. This asymmetry in transport was consistent with the ability of Pz-peptide to lower the transepithelial electrical resistance of Caco-2 cell monolayers only from the mucosal side. Blockade of Na+ access to the apically located amiloride-sensitive Na+ channel in the lower intestinal segments by mucosal 10 microM amiloride, serosal 100 microM ouabain or removal of Na+ ions in the mucosal fluid dramatically reduced Pz-peptide transport to 5% of the control. Moreover, Pz-peptide transport across Caco-2 cell monolayers could be titrated against mucosal Na+ concentration. There was a small mucosal-to-serosal solvent drag effect induced by transepithelial Na+ flux stimulated by Pz-peptide in the colon, contributing in part to enhanced paracellular solute transport. Overall, the above findings are consistent with a scenario whereby Pz-peptide stimulates transepithelial Na+ flux across the colonic segments at the level of the amiloride-sensitive Na+ channel, thereby triggering yet to be identified intracellular biochemical changes that ultimately result in tight junctional opening and enhanced paracellular solute transport.

Amiloride↗

[Evaluation of intraoperative peritoneal cytology and intraperitoneal chemotherapy using CDDP combined with MMC for gastric carcinomatous peritonitis].

A cytological examination in the lavaged peritoneal fluid during operation was performed in 462 patients with gastric cancer. The incidence of positive cytology was 36% in serosal invasion cases. The prognosis of positive cytology cases without peritoneal dissemination was slightly better than the P (+) cases. The incidence of the positive cytology was 48% in patients with serosal invasion more than 16 cm2. The prognosis of patients with serosal invasion below 32 cm2 was significantly better than in the patients with above 32 cm2. Intraperitoneal repeated administration of MMC 10 mg/body and CDDP 40-50 mg/body was continued one a month via the drug delivery system. Negative change of cytology was observed in 7 out of 14 patients, and the prognosis of these patients was better than that of the unchanged cytology group. Side effects such as severe gastrointestinal symptoms and bone marrow toxicities were not observed. Further studies should be done to confirm the efficacy of the intraperitoneal chemotherapy in terms of the prolongation of life.

Adult↗

Antiendothelial cell antibodies and their relation to pulmonary hypertension in systemic lupus erythematosus.

OBJECTIVE: Antiendothelial cell antibodies (aECA) have been demonstrated in patients with systemic lupus erythematosus (SLE), but their role in the pathogenesis of this disease remains unclear. We investigated the association of aECA and anticardiolipin antibodies (aCL) with clinical and laboratory findings in patients with active SLE. METHODS: Sera from 28 patients with active SLE and 22 healthy controls were assayed for IgG and IgM-aECA by cellular ELISA method using cultured human umbilical vein endothelial cells and IgG-aCL by ELISA method. RESULTS: Serum titers of both IgG and IgM-aECA were significantly higher in active SLE than in healthy controls. Titers of IgG-aECA were unrelated to titers of IgG-aCL. Patients with pulmonary hypertension demonstrated a marked elevation of serum titer of both IgG and IgM-aECA compared with patients without pulmonary hypertension. In addition, patients with digital vasculitis showed a significant elevation of serum titer of both IgG and IgM-aECA compared with patients without digital vasculitis. Serum titers of IgG-aECA in patients with Raynaud's phenomenon and of IgM-aECA in patients with serositis were each significantly increased compared with patients without such findings. CONCLUSION: aECA were unrelated to aCL. Serum titers of aECA are elevated in patients with active SLE, especially with pulmonary hypertension, digital vasculitis, Raynaud's phenomenon or serositis. Since pulmonary hypertension in SLE has been associated with digital vasculitis, Raynaud's phenomenon and serositis, aECA may be involved in the pathogenesis of vascular injury, leading to these manifestations.

Antibodies, Anticardiolipin↗

Docosahexaenoic acid and signaling pathways in rabbit colon.

The effects of one of the main components of fish oil, docosahexaenoic acid (DHA), on prostaglandin (PG) and Ca2+ signaling pathways were examined in intact mucosa and freshly isolated crypt cells of rabbit descending colon. Preincubation of serosal mucosa for 20 min with 1 microM DHA fully suppressed the short-circuit and transepithelial conductance increase induced by serosal addition of 10 microM arachidonic acid (AA). DHA at 1 microM also prevented the Cl- secretion promoted by 10 microM AA, as estimated by unidirectional 36Cl flux measurements (net flux = 0.68 +/- 0.30 versus -1.91 +/- 0.20 microEq/hr/cm2, four experiments, p < 0.001), whereas it did not affect the electrophysiological and ion flux responses to PGE2. Addition of 1 microM DHA to the serosal side of the mucosa also inhibited the PG cascade activation elicited by AA (PG synthesis and second messenger cAMP increase). In vitro assays of colonic cyclooxygenase activity showed that 1 microM DHA inhibited (with a 20-min lag) cyclooxygenase activity to the same extent as 5 microM indomethacin (approximately 82% and 80%, respectively). DHA also affected the Ca2+ signaling pathway; in isolated crypt cells, the cytosolic free Ca2+ concentration ([Ca2+]i) dropped by 49 +/- 7.6% (mean +/- standard error, six experiments) after incubation with 1 microM DHA. The sustained phase of the [Ca2+]i response to 500 nM concentrations of the intracellular Ca(2+)-ATPase inhibitor thapsigargin was also inhibited within 150 sec upon 1 microM DHA addition (141 +/- 5.8 versus 243 +/- 8.2 nM [Ca2+]i mean +/- standard error, eight experiments, p < 0.01). The [Ca2+]i-lowering effect of DHA, which was not achieved by incubation with other free fatty acids, was not prevented by removal of Na+ from the incubation medium (-46 +/- 4.3% versus -47 +/- 3.8%, mean +/- standard error, four experiments), nor it was mediated by cAMP-, protein kinase C-, or calmodulin-dependent mechanisms. The incubation of highly purified basolateral membranes of crypt cells with 1 microM DHA for 1 min produced a 5-fold increase (IC50 = 0.25 microM) in the plasma membrane Ca(2+)-ATPase activity (34.3 +/- 2.73 versus 6.02 +/- 0.50 nmol/mg of protein/min, mean +/- standard error, four experiments, p < 0.0001), thus indicating that the DHA effects on the Ca2+ pathway were mediated mainly by an increase in plasma membrane Ca2+ pump activity. These findings suggest that DHA is a powerful modulator of the cellular response to activation of PG and Ca2+ signaling pathways.

Animals↗

Myofibroblast-derived smooth muscle cells during remodelling of rabbit urinary bladder wall induced by partial outflow obstruction.

BACKGROUND: Fibrosis of serosa, along with smooth muscle (SM) cell hypertrophy, has been shown to occur in the rabbit bladder after partial outflow obstruction. Identification of cells involved in the serosal thickening can be of primary interest to elucidate the functional changes that this organ undergoes. EXPERIMENTAL DESIGN: Cytoskeletal protein composition of cells present in the thickened serosa at different times from the onset of obstruction (7, 15, 30 and 60 days) was evaluated. This was accomplished by means of a panel of monoclonal antibodies specific for a number of differentiation markers of mesenchymal cells (vimentin, desmin, alpha-actin of SM type, nonmuscle (NM) and SM myosins), and by immunocytochemical and immunochemical techniques. RESULTS: The immunocytochemical study revealed that cells in serosal thickening follow a two-step maturation process from pre-existing vimentin-positive cells. In the first time period (7 to 15 days of obstruction), these cells predominantly achieved an immunophenotype corresponding to that of a specific myofibroblast subtype (i.e., containing vimentin, NM myosin, and SM alpha-actin). After 30 days from the onset of obstruction, the cytoskeletal protein content of serosal cells, as also revealed by Western blotting experiments, shifted towards that of fetal-type SM cells (i.e., presence of vimentin, NM myosin, SM alpha-actin, and SM myosin isoforms). Distribution of vimentin, desmin, SM alpha-actin, and SM myosin in tissue culture as well as the ultrastructure in vivo very closely resembled that of SM cells. Bromodeoxyuridine incorporation studies indicated that cells accumulated in the serosa of obstructed bladders did not derive, at least initially, from SM cells of the detrusor muscle. CONCLUSIONS: These findings are consistent with the existence of a differentiation process in which resident mesenchymal cells of bladder serosa may transform to myofibroblasts and, subsequently, in fetal-type SM cells during experimental outflow obstruction.

Actins↗

[Spontaneous and induced permeability of the tight junctions in the bladder epithelium of the frog Rana temporaria].

The spontaneous and induced alterations in paracellular permeability of the isolated frog urinary bladder were studied. For estimation of the tight junction (TJ) permeability, a fluorescent dye uranine was used. No morphological or functional evidences for the TJ opening were found in the autumn-winter period, both in the control and after the osmotic flow stimulation by 25 mg/ml pituitrine (P) or serosal mannitol (200 mM). In the spring, a spontaneous uranine efflux through the bladder wall from the mucosal solution was found in parallel with an increase in the basal water flow and a decrease in the responses of the bladder to P and serosal hypertonicity. At the same time, the intercellular substance remained to be a barrier for water. In the autumn-winter the TJ opening could be induced by adding sulfhydryl reagents, p-chloromercury-phenyl-sulfonic acid (PCMPS) or N-ethylmaleimide (NEM), to the serosal solution. However, NEM was effective only when added to the mucosal solution. The uranine efflux induced by sulfhydryl reagents was accompanied with a marked hydroosmotic flow in parallel with a diminished sensitivity to P, the barrier properties of intercellular substances were lost. As evidenced by electron microscopy, PCMPS induced a gradual destruction of TJ structures, while certain cytoplasmic structures were not affected. The uranine efflux in the autumn-winter frogs could be induced by an artificial osmotic gradient after preincubation of the bladders in the isotonic solution with P. Some possible intracellular mechanisms causing both spontaneous and induced alterations in the TJ permeability are discussed.

Animals↗