Clara cell protein (CC16) in pleural fluids: a marker of leakage through the visceral pleura

Pleural fluid (PF) proteins either derive from serum by diffusion or are locally secreted within the pleural space. Another hypothetical origin is a leakage of lung secretory proteins across the visceral pleura. To test this hypothesis, we investigated the occurrence, sources, and determinants in PF of CC16, a small-size and readily diffusible protein of 16 kDa secreted by bronchiolar Clara cells. CC16 concentration was determined by a sensitive latex immunoassay in serum and PF of 117 subjects (86 exudates and 31 transudates) and, for purpose of comparison, in ascites samples from another group of 38 subjects (7 exudates and 31 transudates). CC16 was also studied in serum and PF of normal rats and in rats with pleural exudate induced by alpha-naphthyl-thiourea (ANTU). The levels of CC16 in PF and ascites were highly correlated with that in serum, suggesting a diffusional exchange across the pleural/blood and peritoneal/blood barriers. Whereas CC16 occurs at similar levels in ascites and serum, the protein was found to be more concentrated in PF than in serum in both humans (geometric mean in microg/L, 26.2 versus 14.6, p < 0.0001) and rats (213 versus 16.2, p < 0.001). A local synthesis of CC16 appeared unlikely in view of the lack of CC16-immunostaining in pleura of both species. The only plausible explanation for these findings is that CC16 in PF originates from two sources: diffusion from plasma and a leakage from the lung into the pleural space across the semipermeable visceral pleura. This interpretation is supported by a markedly increased leakage of CC16 in experimental exudates induced by ANTU and the finding of high CC16 concentrations in human transudates associated with congestive heart failure, two conditions wherein PF has been shown to arise from the interstitial spaces of the lung.

Cellular characterization of the 91kDa-ectopic ascitic antigen sharing antigenicity with MRP8 in the human placenta as revealed by immunoelectron microscopical colloidal-gold techniques

Cellular characterization of the 91kDa-ectopic ascitic protein that exhibits pregnancy-associated and tumour-related dynamics has been examined in the human placenta using an electron microscopic immunocolloidal-gold technique. This protein was initially isolated from the ascitic fluids of a patient suffered from ovarian and uterine cancers with mixed mesodermal tumours, and determined to be sharing antigenicity with the 28kDa-oncodevelopmental protein and a calcium-binding protein; MRP8/CFA, respectively. Placentas obtained were divided into three groups by their gestational periods. Small chorionic villous tissues were embedded in Lowicryl K4M resin or Epon 812 resin. Specific and higher labelings by gold-particles were obtained in sections of Lowicryl resin and, then, recognized in mesenchyme-derived cells and/or myeloid lineages; such as placental tissue macrophages (Hofbauer cells), fibroblasts, foetal myelomonocytic cells including endothelial cells, etc., in the first and second trimesters. So far, the pattern of antigenic appearances changed depending on the stage of gestation. On the other hand, 91kDa-protein was also determined in the syncytiotrophoblast, but not in cytotrophoblasts at whenever been examined. It is assumed that the antigenic expression in syncytiotrophoblasts might be reflected to be absorbed or incorporated from those of foetal or maternal origins, and the antibody used in this study should be sensitive to the antigenic epitope derived from those of myeloid lineages. In the light of these results, hypotheses concerning mechanisms of both transplacental permeability of substances by the placental barrier and cell/tissue differentiation by calcium-binding (and/or -depending) proteins such as 91kDa-protein, MRP8, etc.; presumable the S-100 protein family, are discussed further.

Putrescine-stimulated intracellular Ca2+ release for invasiveness of rat ascites hepatoma cells

Our previous study showed that treatment of highly invasive rat ascites hepatoma (LC-AH) cells with alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, decreased both their intracellular level of putrescine and their in vitro invasion of a monolayer of calf pulmonary arterial endothelial (CPAE) cells, and that both these decreases were completely reversed by exogenous putrescine, but not spermidine or spermine. Here we show that all adhering control (DFMO-untreated) cells migrated beneath CPAE monolayer with morphological change from round to cauliflower-shaped cells (migratory cells). DFMO treatment increased the number of cells that remained round without migration (nonmigratory cells). Exogenous putrescine, but not spermidine or spermine, induced transformation of all nonmigratory cells to migratory cells with a concomitant increase in their intracellular Ca2+ level, [Ca2+]i. The putrescine-induced increase in their [Ca2+]i preceded their transformation and these effects of putrescine were not affected by antagonists of the voltage-gated Ca2+ channel, but were completely suppressed by ryanodine, which also suppressed the invasiveness of the control cells. The DFMO-induced decreases in both [Ca2+]i and the invasiveness of the cells were restored by thapsigargin, which elevated [Ca2+]i by inhibiting endoplasmic Ca2+-ATPase, indicating that thapsigargin mimics the effects of putrescine. These results support the idea that putrescine is a cofactor for Ca2+ release through the Ca2+ channel in the endoplasmic reticulum that is inhibited by ryanodine, this release being initiated by cell adhesion and being a prerequisite for tumor cell invasion.

Nitric oxide synthase (NOS) inhibition for one week improves renal sodium and water excretion in cirrhotic rats with ascites

Normalization of the increased vascular nitric oxide (NO) generation with low doses of NG-nitro-L-arginine methyl ester (L-NAME) corrects the hemodynamic abnormalities of cirrhotic rats with ascites. We have undertaken this study to investigate the effect of the normalization of vascular NO production, as estimated by aortic cyclic guanosine monophosphate (cGMP) concentration and endothelial nitric oxide synthase (eNOS) protein expression in the aorta and mesenteric artery, on sodium and water excretion. Rats with carbon tetrachloride-induced cirrhosis and ascites were investigated using balance studies. The cirrhotic rats were separated into two groups, one receiving 0.5 mg/kg per day of L-NAME (CIR-NAME) during 7 d, whereas the other group (CIR) was administrated the same volume of vehicle. Two other groups of rats were used as controls, one group treated with L-NAME and another group receiving the same volume of vehicle. Sodium and water excretion was measured on days 0 and 7. On day 8, blood samples were collected for electrolyte and hormone measurements, and aorta and mesenteric arteries were harvested for cGMP determination and nitric oxide synthase (NOS) immunoblotting. Aortic cGMP and eNOS protein expression in the aorta and mesenteric artery were increased in CIR as compared with CIR-NAME. Both cirrhotic groups had a similar decrease in sodium excretion on day 0 (0.7 versus 0.6 mmol per day, NS) and a positive sodium balance (+0.9 versus +1.2 mmol per day, NS). On day 7, CIR-NAME rats had an increase in sodium excretion as compared with the CIR rats (sodium excretion: 2.4 versus 0.7 mmol per day, P < 0.001) and a negative sodium balance (-0.5 versus +0.8 mmol per day, P < 0.001). The excretion of a water load was also increased after L-NAME administration (from 28+/-5% to 65+/-7, P < 0.05). Plasma renin activity, aldosterone and arginine vasopressin were also significantly decreased in the CIR-NAME, as compared with the CIR rats. The results thus indicate that normalization of aortic cGMP and eNOS protein expression in vascular tissue is associated with increased sodium and water excretion in cirrhotic rats with ascites.

The role of intravenous immunoglobulin in the prevention of severe ovarian hyperstimulation syndrome

PURPOSE

The role of intravenous immunoglobulin (IVIG) in the prevention of severe ovarian hyperstimulation syndrome (OHSS) was evaluated.

METHODS

Ovarian hyperstimulation was induced in eight rabbits using human menopausal gonadotropin/human chorionic gonadotropin (hMG/hCG) after pretreatment with IVIG (IVIG group) or bovine serum albumin (BSA group). Main outcome measures included (1) signs of OHSS, such as the degree of ascites formation and the increase in body weight; and (2) the degree of ovarian stimulation as reflected by serum sex-steroid hormone levels.

RESULTS

A significantly lower ascites response and a tendency toward a decreased change in body weight were observed in the IVIG group compared to the BSA group. Serum estradiol, progesterone, total protein, and ovarian weights were not statistically different between the two groups.

CONCLUSIONS

IVIG prevented severe OHSS in a rabbit model, whereas BSA did not. Further studies are justified in an attempt to clarify the role of the immune system and IVIG in the pathophysiology and prevention of severe OHSS.

[Unexpected origin of recurrent ascites: apropos of 2 cases]

The authors report the cases of two patients suffering from ascites attributed for several years to a non pericarditic aetiology. The first patient presented with a diagnosis of right cardiac failure secondary to a right myocardial infarction. Cardiac catheterisation, magnetic resonance imaging and transoesophageal echocardiogram allowed to establish the diagnosis. In the second case, ascites was attributed to cirrhosis. Presence of pericardial calcifications, visible on a chest X-Ray led to suspect constrictive pericarditis. In both cases, ascites contained a high protein level. A pericardectomy allowed a favourable outcome in both cases. Thus, a diagnosis of constrictive pericarditis must be evoked in face of ascites of unclear origin and a normal cardiac size.

Phase I/II trial of batimastat, a matrix metalloproteinase inhibitor, in patients with malignant ascites

Matrix metalloproteinases have been shown to be important in tumour invasion and metastasis, and the use of matrix metalloproteinase inhibitors in animal models has suggested that these agents may be useful in the control of malignant disease. This article reports the results of an early clinical trial of batimastat, one of the first generation of metalloproteinase inhibitors, in patients with malignant ascites. The drug was well absorbed via the intraperitoneal route and associated with few side-effects. Furthermore, a response to treatment was seen in about half the evaluable patients with advanced malignant disease. The results suggest that further research on the use of matrix metalloproteinase inhibitors in patients with malignant disease is worthwhile.

Recombinant epithelial cell mucin (MUC-1) expressed in baculovirus resembles antigenically tumor associated mucin, target for cancer immunotherapy

Epithelial cell mucin encoded by the gene MUC-1, is expressed on several human adenocarcinomas in an aberrantly glycosylated form, and as such it has been identified as the target of human cellular as well as humoral responses. In order to harness this immunity to combat mucin-expressing tumors, various forms of this molecule, synthetic or highly purified, are being tested as possible cancer vaccines. We have expressed MUC-1 in baculovirus, and we report that the recombinant product has important similarities with the MUC-1 expressed on tumors, especially in regard to its aberrant glycosylation.

Cure of malignant ascites and generation of protective immunity by monoclonal antibody-targeted activation of a glucuronide prodrug in rats

We examined the in vivo efficacy of targeting beta-glucuronidase (betaG) to activate a glucuronide prodrug (BHAMG) of p-hydroxyaniline mustard (pHAM) at hepatoma ascites in Sprague-Dawley rats. Injection i.p. of 500 microg RH1-betaG, a conjugate formed between recombinant betaG and monoclonal antibody RH1 with specificity for an antigen expressed on AS-30D rat hepatoma cells, into rats bearing AS-30D ascites resulted in the accumulation of 54 microg conjugate per 10(9) tumor cells after 2 hr. Ascites fluid and serum contained 0.53 and 0 microg/ml, respectively, RH1-betaG 2 hr after injection of the conjugate. Conjugate binding to AS-30D cells was heterogeneous and non-saturated, as determined by flow cytometry. BHAMG was less toxic than pHAM to SD rats based on measures of animal mortality, weight loss and hematological toxicity. Treatment of rats bearing established hepatoma ascites with 500 microg RH1-betaG followed 2 hr later with a single i.p. injection of 30 mg/kg BHAMG or 3 i.p. injections of 10 mg/kg BHAMG 2, 3 and 4 hr later resulted in the cure of 6/8 and 8/8 animals, respectively. Treatment with BHAMG or pHAM alone did not produce cures, whereas treatment with a control antibody-betaG conjugate and BHAMG produced significantly greater hematological toxicity compared to treatment with RH1-betaG and BHAMG. All cured rats were completely protected from rechallenge with 2 x 10(7) AS-30D cells, indicating that successful treatment of animals induced protective immunity.

Effect of dietary dl-alpha-tocopherol on tissue alpha- and gamma-tocopherol and pulmonary hypertension syndrome (ascites) in broilers

The objectives of this experiment were to determine the effects of high dietary levels of vitamin E on growth performance and pulmonary hypertension syndrome (PHS) mortality. Male broiler chicks (Cobb 500) were randomly assigned to one of four dietary treatments consisting of standard starter and grower diets supplemented with 0, 17, 46, and 87 mg dl-alpha-tocopherol acetate/kg. To encourage the development of PHS, air temperature in the house was 32 and 28 C for Weeks 1 and 2, dropped to 18 C during Week 3, and kept between 10 and 15 C during Weeks 4 through 7. Also, chicks were placed in floor pens on litter used for five previous flocks and ventilation reduced to increase dust and ammonia in the house. Ammonia levels increased from an initial 18 to 36 ppm on Day 42 with the increase in ammonia corresponding to an obvious increase in dust in the air. Lung and liver tissue obtained at 2, 5, and 7 wk of age were analyzed for tissue alpha- and gamma-tocopherol by liquid chromatography. Dietary vitamin E had no effect on body weight, feed intake, or feed efficiency. Cumulative PHS mortality through 7 wk of age was 21% and was also unaffected by dietary treatment. Liver and lung alpha-tocopherol concentrations exhibited a dose-response increase to dietary tocopherol and there was a high correlation between lung and liver tissue alpha-tocopherol (r = 0.72, P < 0.05). Whereas gamma-tocopherol concentrations in lung and liver were unaffected by dietary treatment, liver and lung exhibited age-dependent increases in both alpha- and gamma-tocopherol. Despite dose-dependent increases in tissue alpha-tocopherol, supplementation of diets with up to 87 mg dl-alpha-tocopherol acetate had no effect on growth performance or PHS mortality in broilers under the conditions used in this study.

Cell swelling activates phospholipase A2 in Ehrlich ascites tumor cells

Ehrlich ascites tumor cells, loaded with 3H-labeled arachidonic acid and 14C-labeled stearic acid for two hours, were washed and transferred to either isotonic or hypotonic media containing BSA to scavenge the labeled fatty acids released from the cells. During the first two minutes of hypo-osmotic exposure the rate of 3H-labeled arachidonic acid release is 3.3 times higher than that observed at normal osmolality. Cell swelling also causes an increase in the production of 14C-stearic acid-labeled lysophosphatidylcholine. This indicates that a phospholipase A2 is activated by cell swelling in the Ehrlich cells. Within the same time frame there is no swelling-induced increase in 14C-labeled stearic acid release nor in the synthesis of phosphatidyl 14C-butanol in the presence of 14C-butanol. Furthermore, U7312, an inhibitor of phospholipase C, does not affect the swelling induced release of 14C-labeled arachidonic acid. Taken together these results exclude involvement of phospholipase A1, C and D in the swelling-induced liberation of arachidonic acid. The swelling-induced release of 3H-labeled arachidonic acid from Ehrlich cells as well as the volume regulatory response are inhibited after preincubation with GDP beta S or with AACOCF3, an inhibitor of the 85 kDa, cytosolic phospholipase A2. Based on these results we propose that cell swelling activates a phospholipase A2--perhaps the cytosolic 85 kDa type--by a partly G-protein coupled process, and that this activation is essential for the subsequent volume regulatory response.

Urinary endothelin-like immunoreactivity in patients with cirrhosis

BACKGROUND/AIMS

To investigate a possible relationship between the renal production of endothelin and the presence of renal dysfunction and activation of vasoactive systems in cirrhosis, the urinary excretion and the circulating plasma levels of immunoreactive endothelin (irET) and the plasma levels of vasoactive hormones were measured in 19 healthy subjects, 12 cirrhotic patients without ascites and 39 patients with ascites and different degrees of renal dysfunction.

METHODS

The urinary excretion and the circulating levels of irET were assessed after 5 days on a 40 mEq sodium diet and off diuretics. Renal function parameters and the plasma levels of vasoactive hormones were also measured.

RESULTS

Patients with and without ascites had similar values of urinary irET as compared with healthy subjects (30+/-3, 31+/-3 and 29+/-2 ng/day, respectively, p>0.10). By contrast, patients with ascites had higher circulating levels of irET (15+/-1.2 pg/ml) than patients without ascites and healthy subjects (11+/-1.6 and 5+/-0.4 pg/ml, p<0.01). In patients with cirrhosis, no correlation was found between urinary irET and circulating irET. Moreover, urinary irET did not correlate with liver tests, serum and urine sodium, glomerular filtration rate or vasoactive substances. Patients with hepatorenal syndrome had similar urinary irET to patients with ascites without hepatorenal syndrome.

CONCLUSIONS

Urinary excretion of irET is not increased in cirrhotic patients with ascites and does not correlate with abnormalities in renal function.

Alpha-1 acid glycoprotein is an immunosuppressive factor found in ascites from ovaria carcinoma

BACKGROUND

Although the ascites of patients with ovarian carcinoma has been reported to contain immunosuppressive factors, the identity and source of this activity has not been fully elucidated. The objective of this study was to describe the purification of a single immunosuppressive protein, alpha-1 acid glycoprotein, from ovarian carcinoma ascites, identify its site of production, and describe a possible mechanism by which it inhibits lymphocytes.

METHODS

Ascites from proteins from five patients with epithelial ovarian carcinoma first were differentially precipitated by size with different concentrations of polyethylene glycol and then separated on the basis of isoelectric focusing. The protein factions then were placed in a lymphocyte proliferation assay to determine immunosuppressive activity. Western blot analysis was used to identify alpha-1 acid glycoprotein as an immunosuppressive protein in ascites. Total RNA was extracted from ovarian and hepatic cell lines as well as primary and recurrent ovarian tumor samples. Reverse-transcriptase polymerase chain reaction then was utilized to identify the site of production of this protein. Purified alpha-1 acid glycoprotein was placed in lymphocyte culture and its effects on lymphocyte interleukin-2 (IL-2) production were measured by enzyme-linked immunoadsorbent assay.

RESULTS

Addition of purified alpha-1 acid glycoprotein to the lymphocyte assay resulted in a 60% decrease in lymphocyte proliferation (P < 0.05). Alpha-1 acid glycoprotein transcript was not identified in ovarian tumor cells. The addition of purified alpha-1 acid glycoprotein to the lymphocyte culture resulted in a 65% decrease in IL-2 secretion into the media (P < 0.05).

CONCLUSIONS

Alpha-1 acid glycoprotein is an immunosuppressive protein purified from ovarian carcinoma ascites. It is not expressed primarily by ovarian carcinoma cells. It appears to inhibit IL-2 secretion by lymphocytes.

Purification and characterization of novel whey glycoprotein WGP-88 which binds to a monoclonal antibody to PAS-4 glycoprotein in the bovine milk fat globule membrane

A monoclonal antibody to the PAS-4 glycoprotein (78 kDa) of the bovine milk fat globule membrane (MFGM) specifically recognized PAS-4, and was named KAS4. A component recognized by KAS4 was found in whey protein, this being a glycoprotein of 88 kDa by SDS-PAGE and named WGP-88. WGP-88 was purified and characterized in comparison with PAS-4. WGP-88 had apparent pI values of 6.45 and 6.39, while those of PAS-4 were 7.39 and 7.35. Neuraminidase digestion shifted the pI values of WGP-88 to 6.57 and of PAS-4 to 7.52. WGP-88 was rich in polar amino residues (44.9 mol%), while PAS-4 was abundant in nonpolar amino acid residues (48.7 mol%). WGP-88 contained 17.1% of carbohydrate and PAS-4 had 7.2%. The results of reductive hydrolysis, N-glycanase digestion, and a lectin blot analysis suggested that N- and O-linked sugar chains were contained in both glycoproteins. WGP-88 and PAS-4 had a different N-terminal amino acid sequence. WGP-88 and PAS-4 respectively inhibited competitively the binding of KAS4 to PAS-4 and WGP-88. Our studies revealed WGP-88 recognized by KAS4 mAb to be a novel whey protein and to have different biochemical properties from those of PAS-4.

Increases in hematopoietic responses caused by beta-glucans in mice

The effects of various (1-->3)-beta-D-glucans on hematopoietic responses of mice were investigated by measuring colony stimulating activity in sera and ascites of the mice administered glucan. We have demonstrated that the hematopoietic response was increased by various structures of (1-->3)-beta-D-glucans, i.e. soluble glucans (linear, branched, single helix, triple helix) and particulate glucans. From the viewpoint of structure and activity relationships, we found several characteristic features: i) hematopoietic response induced by the particulate glucan disappeared faster than that by the soluble glucans, ii) conformation of the glucans, single vs. triple helix, are relatively independent of the response, iii) linear glucan had a weaker response, and iv) there is a strong strain-dependency of the response. These results corresponded well with the fact that branched (1-->3)-beta-D-glucans, but not linear and not particulate, are often used as biological response modifiers for cancer patients.

Tyrosine kinase inhibition ameliorates the hyperdynamic state and decreases nitric oxide production in cirrhotic rats with portal hypertension and ascites

Tumor necrosis factor-alpha (TNF) causes vasodilatation and a hyperdynamic state by activating nitric oxide (NO) synthesis. Tyrphostins, specific inhibitors of protein tyrosine kinase (PTK), block the signaling events induced by TNF and NO production. A hyperdynamic circulatory syndrome (HCS) is often observed in portal hypertension (PHT). TNF and NO seem to mediate these hemodynamic changes. The aim of this work was to study the effect of PTK inhibition on the systemic and portal hemodynamics, TNF and NO production, in cirrhotic rats with portal hypertension. Rats with liver cirrhosis induced by chronic inhalation of carbon tetrachloride were used. Animals were treated daily with tyrphostin AG 126 (alpha-cyano-(3-hydroxy-4-nitro) cinnamonitrile) or placebo for 5 d. Mean arterial pressure (MAP), heart rate (HR), and portal pressure (PP) were measured by indwelling catheters. Cardiac output (CI) and stroke volume (SV) were estimated by thermodilution, systemic vascular resistance (SVR) was calculated (MAP/CI), and portal systemic shunting (PSS) was quantitated using radioactive microspheres. Serum and mesenteric lymph node (MLN) TNF levels were measured using an immunoassay kit, and serum NOx was determined photometrically by its oxidation products. The AG 126-treated group showed a statistically significant increase in MAP and SVR, and decreases in CI, SV, MLN TNF, and serum NO oxidation products nitrite and nitrate (NOx) in comparison with the placebo-treated rats. No significant differences were noticed in HR, PP, PSS, or serum TNF. Significant correlations were observed between MAP and NOx, MAP and MLN TNF, PSS and NOx, and serum TNF and serum NOx. The HCS observed in PHT seems to be mediated, at least in part, by TNF and NO by the activation of PTKs and their signaling pathways. PTK activity inhibition ameliorates the hyperdynamic abnormalities that characterize animals with cirrhosis and PHT.

Urinary excretion of prostaglandins and renal function after hepatic resection

BACKGROUND/AIMS

The leading postoperative complication associated with hepatic resection is the accumulation of fluid in the abdominal cavity, which usually develops approximately one week after surgery. This study was undertaken to investigate the role of renal prostaglandins in modulating renal sodium and water retention in patients who underwent hepatic resection.

METHODS

Urinary excretion of thromboxane B2 and 6-keto-prostaglandin F1 alpha as well as renal function were investigated serially in 7 patients with hepatocellular carcinoma who underwent hepatic resection. We administered 60 mg of OKY 046, a selective thromboxane A2 synthetase inhibitor, for 6 hours by continuous drip infusion from the commencement of surgery.

RESULTS

Urinary sodium excretion was reduced from 165 mEq/day pre-operatively to 73 mEq/day on postoperative day 6 (p = 0.0181), however, there was no decline in urinary osmorality. OKY 046 administration inhibited intrarenal thromboxane A2 production, on the other hand, it significantly increased the production of intrarenal prostaglandin I2 (from 147 +/- 19 to 6339 +/- 1861 pg/mg creatinine, p = 0.0017) on the day of surgery. The level of thromboxane A2 was significantly increased to 2440 +/- 1099 pg/mg creatinine (p = 0.006, vs. pre-operative value), whereas the level of prostaglandin 12 was significantly reduced to 687 +/- 163 pg/mg creatinine (p = 0.0181, vs. the value on the day of surgery) on postoperative day 6.

CONCLUSIONS

Urinary thromboxane A2 synthesis might contribute to sodium and water retention after hepatic resection. These results suggest that combined use of OKY 046 and diuretics prevent ascites formation after hepatic resection.

Purification and characterization of a DNA binding protein in a nuclear scaffold fraction from rat ascites hepatoma cells

Our most recent work [Hibino et al. (1995) Cancer Lett., 88, 49-55] has shown that the selective binding affinities of highly repetitive DNA components for a nuclear scaffold protein from rat ascites hepatoma cells (P230) depend on the degree of sequence-directed bending of the helix axis. In the present experiment, this protein has been highly purified and isolated by a series of column chromatographic procedures to migrate as a single band to a molecular weight position of 230 kd on a SDS-polyacrylamide gel. A filter binding assay showed that the binding of a repetitive AT-rich component (369 bp XmnI fragment) from the hepatoma nucleus, which has a strongly bent overall structure, to isolated P230 is based on a cooperative mode of interaction. Distamycin A, which binds specifically to AT-rich DNA, removed the bend in the XmnI fragment and inhibited binding to this protein. These results suggest that AT-rich regions in highly repetitive DNA cause bending of the helix axis to be recognized by nuclear scaffold protein(s). Moreover, it has been shown that the nuclear scaffold fraction from rat liver or an actively growing hepatocyte cell line (Ac2F cells) does not contain P230, but does have a repetitive bent DNA binding protein (P130), which has an apparent molecular weight of 130 kd. In addition, the immunoblot analysis showed that mouse anti-P130 antiserum reacts with P230. Thus, the results in the present study imply that there is some difference in the higher order structure of the nuclear DNA attachment region between rat liver or actively growing hepatocytes and the hepatoma, although P230 appears to be immunochemically similar to P130.

Modification of the erythrocyte surface in rats bearing Yoshida ascites sarcoma is brought about by a tumour variant of alpha2-macroglobulin

Erythrocytes from the circulation of rats bearing Yoshida ascites sarcoma exhibit higher concanavalin A (ConA)-mediated agglutinability than those from normal animals. A tetrameric glycoprotein of subunit molecular mass 170 kDa, purified from the cell-free ascites fluid, was found to confer higher ConA-mediated agglutinability on erythrocytes in vitro. An antiserum to this tumour-derived protein failed to detect any cross-reactive component in normal rat plasma or in any of the normal tissues examined. An immunoreactive protein was, however, detected in blood plasma when the acute-phase reaction was stimulated by injection of turpentine. The cross-reactive acute-phase protein was purified by ConA-affinity, gel-filtration and ion-exchange chromatography, and identified as alpha2-macroglobulin. The acute-phase protein and the protein obtained from the ascites fluid have identical or very similar native and subunit molecular masses, subunit arrangement and pI. They both are able to inhibit trypsin and, as a consequence, acquire greater mobility in native PAGE. In addition, the two proteins bind to rat erythrocytes non-specifically, and in similar amounts. However, despite these similarities, the acute-phase protein is unable to enhance the agglutinability of erythrocytes. The two proteins differ in their carbohydrate content, but this differential glycosylation is not the cause of the difference in their surface modification activity. The chemically deglycosylated proteins show a small but consistent difference in the size of their polypeptides. Their tryptic peptide maps, although largely similar, show some differences, as do their amino acid compositions. It is probable that the proteins are independent members of the same (alpha-macroglobulin) family. The rat embryo is also found to express a soluble protein consisting of a 170 kDa polypeptide that cross-reacts with the antibody to the tumour-derived protein. The purified embryo protein is able to alter the ConA-mediated agglutinability of erythrocytes in vitro, and also yields a tryptic peptide map that is identical to that of the tumour-derived protein. The modification of the host cell surface in the tumour-bearing rats is thus caused by what appears to be a tumour (oncofetal?) variant of alpha2-macroglobulin.

Prorenin and active renin concentrations in plasma and ascites during severe ovarian hyperstimulation syndrome

The pathophysiology of ovarian hyperstimulation syndrome (OHSS) remains unclear. Several lines of evidence indicate that OHSS is associated with a stimulation of the renin-angiotensin system (RAS), but its functional significance as well as its role in the pathogenesis of the syndrome are not yet determined. OHSS is associated with high plasma and ascitic concentrations of total renin, renin activity (RA) and angiotensin II (Ang II). Their ovarian or renal origin is, however, still a matter of debate. To clarify these issues further, total renin, active renin, prorenin, RA and aldosterone were measured in plasma and ascites of nine patients who developed severe OHSS after in-vitro fertilization. Blood and ascites were sampled simultaneously during therapeutic paracentesis. Total renin and prorenin concentrations were significantly higher in the ascites (mean concentration +/- SE respectively of 5920 +/- 1430 mIU/l and 5250 +/- 1350 mIU/l) than in the plasma (respectively 3060 +/- 740 mIU/l and 2000 +/- 460 mIU/l) (P = 0.020 and 0.017 respectively). Conversely, active renin and RA concentrations tended to be lower, although not statistically significantly so in the ascites (respectively 670 +/- 190 mIU/l and 47 +/- 11 ng Ang I/ml/h) than in the plasma (respectively 1060 +/- 370 mIU/l and 75 +/- 21 ng Ang I/ml/h). Aldosterone concentrations were significantly higher in the serum (2609 +/- 374 pg/ml) than in the ascites (2025 +/- 347 pg/ml) (P = 0.015). The concentration gradient between plasma and ascites for total renin and prorenin supports the hypothesis of their ovarian origin in ascites and, to a large extent, in plasma, while it is likely that the high plasma active renin and RA concentrations reflect a peripheral activation of the RAS. In conclusion, the present findings are consistent with a marked stimulation of both ovarian and renal RAS during OHSS.

Novel glycoproteins inhibiting the binding of colorectal cancer cells to E-selectin

Novel glycoproteins carrying sialyl-LeA (SLeA) antigens (SL-GP) were isolated from ascites fluid from a patient with colorectal cancer by immunoaffinity chromatography. Their characteristics, including binding capacity to E-selectin, were investigated. SL-GP showed a typical mucin type amino acid composition in which Ser, Thr and Pro together accounted for greater than 50% of the total amino acid residues. A large amount of carbohydrate (about 80%) was present in SL-GP. The number of O-glycans carrying SLeA antigens comprised about 9% of the total number of O-glycosidic chains. SL-GP could bind to IL-1 beta treated HUVEC, and the binding was inhibited by anti-E-selectin and anti-SLeA monoclonal antibodies. The binding of colorectal cancer cells, LS 180, to HUVEC was assayed in the presence of SL-GP, oligosaccharides prepared from SL-GP and human milk SLeA hexasaccharide. SL-GP inhibited the binding most effectively, whereas equivalent amounts of the SL-GP oligosaccharides and milk SLeA hexasaccharide inhibited it only slightly. These results constitute direct evidence that a unique arrangement of SLeA antigens on the polypeptide chain, probably a cluster, is essential for the binding to E-selectin.

Treatment of refractory ascites using transjugular intrahepatic portosystemic shunt (TIPS): a caution

Ascites becomes refractory to medical treatment in nearly 10% of cirrhotic patients, who then require repeated large-volume paracentesis. In this prospective study we evaluated the use of transjugular intrahepatic portosystemic shunt (TIPS) in 30 patients with refractory ascites. TIPS was successful in all and resulted in a 54% reduction in portacaval gradient (from 22.8 +/- 0.8 to 10.4 +/- 0.6 mm Hg). Ascites became easily controlled with diuretics in 26 patients following TIPS. Ascites recurrence associated with shunt stenosis was observed during follow-up in eight patients; revision could be undertaken in five of them and resulted in good control of ascites. In responders, a marked decrease in plasma aldosterone and renin activity, a reduction in serum creatinine, and a rise in urinary sodium excretion were observed. Creatinine and inulin clearances improved significantly; PAH clearance remained unchanged. However, new-onset or worsening hepatic encephalopathy was seen in 14 patients. Severe disabling chronic encephalopathy occurred in five patients; it could be reversed successfully by balloon occlusion of the shunt in three. The cumulative survival rate was 41 and 34% at 1 and 2 years, respectively. In summary, TIPS can control refractory ascites in a majority of patients but is associated with a high rate of chronic disabling HE. In addition, the survival rate is poor. Randomized trials are needed to evaluate the exact role of TIPS in the management of refractory ascites. It is unlikely to improve survival but can ameliorate quality of life in nontransplant candidates and be useful as a bridge to transplantation, in particular, to improve denutrition associated with longstanding tense ascites.

Stimulation of albumin synthesis in rat hepatocytes by ascites from patients with cirrhosis

Hepatocyte growth factor (HGF), identified in ultrafiltered ascites and plasma from patients with cirrhosis, enhances the DNA synthesis in adult rat hepatocytes cultured at low cell density. This study was carried out to investigate the effect of ascites and plasma from patients with cirrhosis on liver-specific functions such as albumin synthesis in adult rat hepatocytes cultured at confluent-cell density. Ultrafiltered ascites from patients with cirrhosis and its ascitic protein, partially purified by fractionation with ammonium sulfate and gel filtration on Sephadex G-200, stimulated albumin synthesis in a dose-dependent manner in the presence of 10(-8), M dexamethasone. This effect was greater than that of 10(-7) M insulin and similar to that of 10(-7) M dexamethasone, but was additive with that of insulin plus dexamethasone. The molecular weight of the ascitic factor was estimated as 100,000 to 150,000, corresponding to that of HGF purified from cirrhotic ascites. Moreover, the partially purified ascitic factor markedly stimulated DNA and protein synthesis in hepatocytes. These findings suggest that the ascitic factor may act as HGF by stimulating hepatocyte DNA and albumin synthesis in a cell density-dependent manner.