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At least 19 recordsLinked to original sources
PubMed1990

Targeting of peritoneum by the small numbers of isogeneic and allogeneic ascites carcinoma cells that infiltrate or attach to peritoneum during ascites growth.

In the course of development of an in vivo invasion model, sublines of a series of allogenic and isogeneic carcinoma cell lines have been selected that show enhanced invasion of the peritoneum. It was found that, during the proliferation of tumor cell lines in ascitic form in the abdominal cavity, small numbers of cells infiltrated or firmly adhered to the peritoneum in at least 8/12 of the tumor-host combinations tried. After thorough washing of the peritoneum it was disaggregated by an enzyme mixture, and the resulting mixture of normal and tumor cells was inoculated intraperitoneally. Peritoneal isolations were made serially for 3 to 12 times. In 6 of 8 cases where the isolation produced a stable ascites, the cells showed enhanced peritoneal invasion compared with the parent cell line. The invasion of some of the cell lines was tested in another invasion model consisting of cultured mouse buccal mucosa (9/10 cell lines invaded the explant). In 3/3 cell lines showing enhanced peritoneum invasion in vivo, there was no enhanced invasion of the buccal mucosa. The enhanced peritoneum invasion appears to be tissue specific rather than a general increase in invasion potential. Pairs of high- and low-invasive cell lines were obtained that should be useful for screening for invasion modulating agents using the mouse ascites/peritoneum in vivo model. It is suggested that the method might be generalized to produce various tumor cell lines that target for the normal tissues that are adjacent to proliferating solid or circulating tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

Change in the transport of uric acid under the influence of pyrazinoic acid: in vitro studies with human and rabbit peritoneum.

Bidirectional transport of uric acid (UA) through human and rabbit peritoneum, and its change under the influence of pyrazinoic acid (PA) was investigated in vitro. Fragments of parietal peritoneum were taken from the region of anterior abdominal wall from rabbits (the animal series) and from patients undergoing abdominal operations (the human series). Under control conditions, higher values of the UA transport were found in the rabbit peritoneum in comparison with the human peritoneum, but in both series it was maintained at a constant level throughout the experiment lasting 120 min. In rabbit as well as in human peritoneum it was found that PA depressed about 50% of the UA transport from the interstitial to the mesothelial side, leaving the opposite direction intact. The results obtained in vitro are in agreement with previous observations in a patient undergoing peritoneal dialysis that showed decreased peritoneal UA excretion evoked by pyrazinamide. The comparative analysis proves the rabbit peritoneum to be a good experimental model for further investigations of peritoneal urate transport in man.

Adult↗
PubMed1991

[Changes in the peritoneum of the small intestine and diaphragm in experimental portal hypertension].

Diaphragm and small intestine peritoneum morphology was studied in experimental portal hypertension in rats with the help of luminescent, transmission and scanning electron microscopy techniques. Structural organizations of these peritoneum portions and performance function were different: fluid transudation realized through the small intestine peritoneum and resorption occurred via diaphragm peritoneum. Morphological signs allowed to judge about the increasing of fluid transudation in abdominal cavity and diaphragmatic resorption in early period of portal hypertension. Morphological alterations appeared in peritoneum resorption sites (pumping diaphragmatic hatchs) according to progress of portal hypertension that indicated decompensation process of peritoneal fluid absorption and led to ascites.

Animals↗
PubMed1990

[The human peritoneum and human peritonitis in ultrastructural and immunohistochemical studies].

This paper describes observations of the normal and irritatingly changed morphology of the human peritoneum and about alterations in human peritonitis. The results were obtained by transmission- and scanning electron microscopy, immunohistochemical reactions, and other supplementary light microscopic investigations on surgically collected tissue material. Special attention was given to the superficial structure and the openings of the peritoneum. The superficial liquid film and the microvilli of the mesothelium are influenced by irritative conditions. In the human peritoneum, there are separated areas of small high and of large flat mesothelial cells. The small-cell areas of the peritoneum are connected with openings, special mesothelial cell glades, and cell migrations from deeper parts. There are signs of mesothelial secretion into the peritoneal cavity from mesothelial cells and intercellular spaces of the mesothelium too. The stomata--openings of the peritoneum--are of conditioned character. These depends upon the state of the superficial mesothelium and upon topical loci between the mesothelial cells. Special attention requires the so-called Dreierpunkt. In peritonitis, there are also openings in the fibrin layer. On this condition, the superficial layer of mesothelium mostly becomes destroyed. The keratin reaction is the most essential among the immunohistochemical investigations. It allows to demonstrate preserved mesothelial cells in the deepness of inflammatory tissue in peritonitis.

Adolescent↗
PubMed1989

[Experimental studies on the development of peritoneal adhesions in cases of suturing and non-suturing of the parietal peritoneum in rabbits].

The author performed (in general ether anaesthesia) median upper and lower right oblique laparotomy in 50 rabbits (two incisions in each). In 25 rabbits from group I the author closed the wound without suturing the parietal peritoneum whereas in the remaining 25 rabbits from group II they closed the wound suturing the parietal peritoneum. On 1st, 3rd, 7th, 14th and 21st days following the procedure, 5 rabbits from each group were killed. The author evaluated the wounds of the parietal peritoneum by macro- and microscopy, and also the number of peritoneal adhesions in each group. It was found that in group I adhesions appeared only in 3 out of 50 incisions whereas in group II--17 adhesions out of 50 wounds (p less than 0.005). The author believes that parietal peritoneum that has not been sutured heals better and with a smaller number of adhesions than sutured parietal peritoneum.

Abdominal Muscles↗
PubMed1991

Visceral peritoneum is not essential for solute transport during peritoneal dialysis.

The importance of visceral peritoneum in determining transperitoneal solute exchange was studied by determining the influence of evisceration on diffusive solute transport during peritoneal dialysis. Three series of experiments were performed in anesthetized New Zealand White rabbits. Series 1 studies compared solute transport rates from eviscerated rabbits (N = 5) with those from sham-operated controls (N = 5). Series 2 studies compared solute transport rates from eviscerated (N = 6) and sham-operated rabbits (N = 5) with application of circumferential abdominal compression to control intraperitoneal pressure and presumably maximize dialysate-peritoneum contact. Series 3 studies compared solute transport rates from sham-operated rabbits (N = 4) with and without applied circumferential abdominal compression. Transperitoneal solute exchange of creatinine and FITC-labeled neutral dextran (15 to 40 A) was equally assessed by both the dialysate to plasma concentration ratio at the end of the exchange and the diffusive permeability-area product of the peritoneum. Evisceration reduced creatinine (P less than 0.001) and dextran (15 to 30 A, P less than 0.05) transport to approximately one quarter that of controls in series 1 rabbits. When circumferential abdominal compression was applied in series 2 rabbits, however, evisceration had no effect on peritoneal solute transport rates. Moreover, circumferential abdominal compression per se had no effect on solute exchange in series 3 experiments. These findings demonstrate that the influence of evisceration on peritoneal solute transport depends on the experimental conditions. These observations further demonstrate that visceral peritoneum is not essential for solute transport during peritoneal dialysis.

Animals↗
PubMed1990

[Measuring the thickness of the peritoneum as a dialysis membrane using various osmolar concentrations of dialysis fluid].

Thickness measurements solutions on the rat peritoneum using peritoneum using peritoneal dialysis solutions of various osmolalities show a marked reduction of the distances between capillaries and peritoneal surface with increasing osmolality. This may caused by a dehydration of the peritoneum and support the so-called canaliculus theory. If the dehydration of the peritoneum may outlast temporal the dialysis cycle with higher osmolar solution, it could be an explanation for the efficacy of following low-molecular solutions.

Animals↗
PubMed1989

[Human peritoneum in vitro: changes in urate transport after administration of pyrazinoic acid].

The article is an analysis of the dynamics of two-direction transportation of uric acid (UA) through the human peritoneum in vitro, and also changes of the dynamics under the influence of pyrazinoic++ acid. The peritoneum was taken from the anterior abdominal wall of patients undergoing planned abdominal surgery. It was found that the transportation of UA both from the vascular to the mesothelial side of the peritoneal membrane and in the opposite direction remained on a stable level for 120 minutes. The introduction of pyrazinoic++ acid decreased the transportation of UA from the vascular to the mesothelial side of the peritoneum on the average by 50 per cent. The transportation in the opposite direction did not change. The results obtained are consistent with results of clinical examinations. One may suppose that pyrazinoic++ acid induces changes in transportation qualities of the peritoneum.

Adult↗
PubMed1979

Fibrinolytic activity of the peritoneum during experimental peritonitis.

The effect of laparotomy, intestinal resection, heparin and bacterial peritonitis on fibrinolysis of the peritoneum was evaluated in dogs. Heparin had no effect. Sterile laparotomy and intestinal resection severely, but incompletely, reduced fibrinolytic activity measured 24 hours after operation. Fibrinopurulent peritonitis induced by creation of a 10 centimeter long ischemic loop of the terminal part of the ileum abolished the fibrinolytic activity of the peritoneum almost completely. The data are consistent with findings that adhesion formation is inversely correlated with the fibrinolytic activity of the peritoneum. Untreated peritonitis abolished that activity by mechanisms as yet not elucidated. Heparin, which has been shown to reduce both adhesion-formation and the lethality of peritonitis, apparently does so by mechanisms independent of the intrinsic fibrinolytic system of the peritoneum.

Animals↗
PubMed1990

New concepts in molecular biology and ultrastructural pathology of the peritoneum: their significance for peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) was developed into a life-maintaining therapy using a membrane whose fundamental biological characteristics were largely unknown. Recognition of this deficiency in our knowledge spurred a belated explosion of research that began with an exploration of the fine structure of the mesothelium. The monolayer of lining cells was found to be more sophisticated than previously imagined, being profusely carpeted with microvilli and bearing motile cilia, and in contrast to endothelium, was shown to possess a cytoplasm replete with organelles in which rough endoplasmic reticulum and lipid inclusions are prominent. Because these findings indicated possible secretory function, a link was sought between these observations and the discovery in effluent dialysate of phosphatidylcholine, a lubricant surfactant. Subsequently, comparison of mesothelial ultrastructure with that of type 2 pneumocytes revealed close concordance, while specialized fixation techniques developed for the preservation of lamellar bodies (the known storage vesicles of alveolar surfactant), when applied to mesothelium, for the first time revealed similar cytoplasmic inclusions. In vitro studies have shown that mesothelium, when incubated with radiolabeled precursor, is capable of synthesizing phosphatidylcholine, the principal constituent of pulmonary surfactant, in amounts similar to those produced by lung. The demonstration that the intensively studied type 2 pneumocyte and mesothelium both secrete lamellar bodies has opened up new possibilities in exploring the physiology, pharmacology, and pathology of the peritoneum. Recent work on mesothelial cell culture has shed new light on the factors involved in healing and regeneration. Recognition of the existence of subserosal multipotential cells and their importance in maintaining the integrity of the mesothelial cell layer is dawning. From the study of peritoneal biopsies in CAPD patients, evidence is accumulating that a process of nonenzymatic glycosylation of protein, similar to that which occurs in diabetes, is responsible for changes in stromal texture and the reduplication of basement membranes. Appreciation of stromal vulnerability to dialysate-induced accelerated aging following mesothelial loss may therefore require a new approach to peritoneal dialysis during peritonitis. Now that CAPD approaches clinical maturity there is increasing recognition of the need for strategies to ensure long-term preservation of the peritoneum as a dialyzing organ. Concomitantly there is a realization that these goals can only be attained through a much deeper appreciation of the molecular biology and pathology of the peritoneum itself.

Animals↗
PubMed1990

Serous borderline tumors of the peritoneum.

The clinicopathological features of 25 cases of peritoneal serous neoplasms histologically identical to noninvasive implants of ovarian serous borderline tumors but with minimal or no ovarian surface involvement were reviewed. The patients ranged in age from 19 to 53 (mean, 31) years; 18 of them were under 35 years of age. Infertility and abdominal pain were the most common presenting complaints. An extraovarian mass was present in two patients; adhesions or granularity of peritoneal surfaces were described in 23 of them. In 21 cases only the pelvic peritoneum was involved; the upper abdominal peritoneum was involved additionally in four cases. Most of the women were treated by hysterectomy, bilateral salpingo-oophorectomy, and omentectomy; six of them received chemotherapy postoperatively and two received both chemotherapy and radiation therapy. Nine women had a more limited operation to preserve their fertility. The 25 patients were followed for 4 to 13.9 (mean, 8) years. There was no clinical evidence of recurrence in 21 women. Borderline tumor recurred in two patients, who remained well for 1.7 and 2 years after excision of the recurrent tumor. Invasive low-grade serous carcinoma of the peritoneum developed in one woman who was living with extensive intra-abdominal tumor at the last follow-up examination. One woman died of disseminated SBT, which was diagnosed cytologically but not confirmed by biopsy.

Adult↗
PubMed1979

Preparation of parietal peritoneum for measurements of in vitro permeability.

An experimental method for in vitro studies of permeability of parietal peritoneal membrane was developed in rats. Sodium and potassium fluxes across the peritoneum lining two different regions (the diaphragm and the anterior abdominal wall) were estimated and electrical resistance of the isolated membranes were determined. A significant reciprocal correlation was observed between the two indices. Quantitative differences between the two types of membranes were found, the diaphragmatic region being more permeable than the other. It is suggested that a monolayer of mesothelial cells covering the membranes is partially responsible for these differences. The parietal peritoneum was found to be less permeable than visceral peritoneum (mesentery) studied under identical conditions.

Abdominal Muscles↗
PubMed1989

Morphology of the peritoneum in CAPD.

Stimulated by the development of continuous ambulatory peritoneal dialysis (CAPD), it was only in the last decade that normal and dialysate-exposed peritoneum were examined by electron microscopy. Biopsies of parietal peritoneum from patients on CAPD show ultrastructural alterations in the mesothelium consisting of an increased development of the rough endoplasmic reticulum but a decrease in surface microvilli and micropinocytotic vesicles as compared to tissue from normal controls or uremic individuals. Alterations in amount and consistency of submesothelial ground substance, and number and disposition of collagen fibers combined with mesothelial changes together constitute the 'reactive' peritoneum of peritoneal dialysis.

Fibrosis↗
PubMed1988

Ruthenium-red-stained anionic charges of rat and mice mesothelial cells and basal lamina: the peritoneum is a negatively charged dialyzing membrane.

The peritoneum has been classically considered to be an inert passive membrane. Previous studies demonstrated the presence of fixed anionic charges at the level of the peritoneal microvasculature and the subserosal interstitium. The present study describes the selective distribution of fixed anionic charges in the mesothelial cell plasmalemma and organelles as well as in the submesothelial basal lamina of rat and mice visceral, parietal and diaphragmatic peritoneum. These data support the idea that the peritoneum should be considered a negatively charged biological dialyzing membrane with selective capabilities. Therefore, transperitoneal transfer of charged solutes cannot be analyzed just on the basis of their molecular weight, size and shape.

Animals↗
PubMed1991

A randomized study of closure of the peritoneum at cesarean delivery.

This study was conducted to test the hypothesis that nonclosure of the visceral and parietal peritoneum during low transverse cervical cesarean delivery is not associated with increased intraoperative or immediate postoperative complications. One hundred thirteen patients scheduled for low transverse cervical cesarean were randomized to either closure of both the visceral and parietal peritoneum with absorbable suture (N = 59) or no peritoneal closure (N = 54). Patients were cared for in the usual postoperative manner without reference to treatment group. There were no demographic differences between the groups and no differences in method(s) of anesthesia, operative indication(s), or use of peripartum epidural narcotics. The incidence of fever, endometritis, or wound infection was similar between groups. There were no differences in the number of patients requiring parenteral narcotic analgesia or in the number of doses per patient. The number of oral analgesic doses was significantly greater with closure than without (P = .014). The frequency with which postoperative ileus was diagnosed in each group was similar, and there was no difference regarding the day on which patients were advanced to liquid or select diets. Bowel stimulants were administered more frequently to the closure than to non-closure patients (P = .03). The average operating time was shorter for the open group than for the closure group (P less than .005). We conclude that non-closure of the visceral and parietal peritoneum at low transverse cervical cesarean delivery appears to have no adverse effect on immediate postoperative recovery, may decrease postoperative narcotic requirements, allows less complicated return of bowel function, and provides a simplified and shorter surgical procedure.

Adult↗
PubMed1990

Tissue reactivity and degradation patterns of absorbable vascular ligating clips implanted in peritoneum and rectus fascia.

Absorbable vascular ligating clips are finding increasing use in intraabdominal surgery. We report the results of a light and scanning electron microscope investigation of the tissue reactivity and clip degradation patterns of two such materials, Absolok (polydioxanone) and Lactomer (copolymer of glycolic and lactic acid), implanted in the fascia and peritoneum of rabbits for intervals of 2 to 70 days. Cellular response to the clips, defined as the number of inflammatory cells/10(4) microns 2, was maximum at day 4 postimplantation, then gradually declined as the duration of implantation increased. This pattern, seen with both types of clips, was similar to that seen with polydioxanone (PDS) suture, but significantly greater than that associated with polypropylene (Prolene) suture. Although cellular response to the clips was greater in peritoneum than in fascia, especially on two occasions associated with adhesion formation, this was not statistically significant. Based on our morphological observations, the signs of clip degradation which were indicated by the appearance of surface crazing and cracks occurred earlier in peritoneum than in fascia.

Abdomen↗
PubMed1989

Cystic mesothelioma of the peritoneum.

Cystic mesothelioma (CM) of the peritoneum is a rare, benign neoplasm that occurs predominantly in women and tends to recur locally. It has received little attention (to our knowledge, a single case report) in the radiology literature. Five cases of CM are presented. Computed tomography (CT) was performed in three cases, ultrasound (US) in four cases, and magnetic resonance (MR) imaging in one case. Twenty-eight cases reported in the literature are reviewed for comparison. CM shows a clear predilection for the surfaces of the pelvic viscera but is seen in other areas of the peritoneum and retroperitoneum. The neoplasm was intraperitoneal in three cases and primarily retroperitoneal in the other two cases. In all CT and US studies performed, a single large, multilocular cystic mass was demonstrated. MR imaging, performed in one case, showed that the lesion had signal characteristics typical of a watery collection low in solute concentration. It is concluded that CM of the peritoneum has a nonspecific multilocular cystic appearance on images, which does not permit it to be differentiated from other cystic lesions.

Adult↗