Identification and characterization of a homozygous deletion found in ovarian ascites by representational difference analysis.
We have performed representational difference analysis (RDA) on DNA from tumor cells and normal fibroblasts isolated from the ascites of a patient with ovarian cancer. Five of six products of the RDA were homozygously deleted from the tumor DNA. One of these products has been characterized and identifies a homozygous deletion of approximately 6.9 Mb at chromosome 9p21 in the original ovarian tumor material. This deletion encompasses CDKN2A (p16), CDKN2B (p15), and IFN-alpha. PCR analysis of other tumor cell lines using the novel STS based on the RDA product has shown it to lie between IFN-alpha and p16, and to identify the distal extent of a homozygous deletion in another ovarian cancer cell line. These data provide further evidence for a tumor suppressor locus distinct from, but mapping close to, p16 on 9p21. Cytogenetic analysis using comparative genomic hybridization (CGH) performed on the same primary tumor confirmed a loss of material from chromosome 9p. However, the CGH technique had neither the resolution nor the sensitivity to define a subregion of homozygous loss. (+info)
Antibiotic penetrance of ascitic fluid in dogs.
Antibiotic concentrations in ascitic fluid after parenteral therapy may be important in the treatment of peritonitis. We have created ascites in dogs by partial ligation of the inferior vena cava. Ascitic fluid volume was measured at the time each antibiotic was administered. Nine antibiotics were studied in the same three dogs. Antibiotic concentration in ascitic fluid was found to vary inversely with ascites volume. Percentage of penetration (ratio of ascites peak to serum peak x100) ranged from 5.8 to 65% among the drugs studied. Only metronidazole showed a statistically significant higher percentage of penetration than other antimicrobials. Concentrations in ascitic fluid after single doses of cephalothin (15 mg/kg) and the aminoglycosides (2 mg/kg, gentamicin and tobramycin; 7.5 mg/kg, amikacin and kanamycin) did not exceed the minimum inhibitory concentration of many gram-negative rods and may justify the use of higher than usual initial parenteral doses, or possibly initial intraperitoneal administration in seriously ill patients. (+info)
An endonuclease from mouse cells specific for single-stranded DNA.
An endonuclease with a molecular weight of about 70000 (5-6S) was extensively purified from mouse ascites cells. The enzyme specifically attacks single-stranded DNA which is degraded mainly to oligonucleotides, with 5-10 residues. Supercoiled covalently closed circular phage DNA is converted to the linear relaxed form. The enzyme activity is highly sensitive to salt and can be stimulated by reagents lowering the dielectric constant of the buffer such as dimethylsulfoxide and glycerol. (+info)
Hyperreactio luteinalis associated with chronic renal failure.
Hyperreactio luteinalis is a rare benign condition characterized by bilateral ovarian enlargement associated with pregnancies where high concentrations of maternal serum human chorionic gonadotrophins are present. This condition may mimic the ovarian hyperstimulation syndrome. We report a case of a 34 year old woman with a history of chronic renal failure on haemodialysis who presented at 10 weeks' gestational age with hyperreactio luteinalis which was treated conservatively. Because of chronic renal failure, the presentation and course of the disease was different from that which has been previously reported. (+info)
Lymph and pulmonary response to isobaric reduction in plasma oncotic pressure in baboons.
Plasma colloid osmotic pressure was reduced by 76% (from 19.6 +/- 0.6 to 4.7 +/- 1.5 mm Hg) in five baboons while pulmonary capillary hydrostatic pressure was maintained at a normal level. This resulted in fluid retention, weight gain, peripheral edema and ascites, but no pulmonary edema. Thoracic duct lymph flow increased 6-fold and pulmonary lymph flow 7-fold. Thoracic duct lymph had a lower colloid osmotic pressure (2.0 +/- 0.7 mm Hg) than plasma (4.7 +/- 1.5 mm Hg), whereas the colloid osmotic pressure of pulmonary lymph (4.7 +/- 0.7 mm Hg) was the same as that of plasma. The lymph-plasma ratio for albumin fell in thoracic duct lymph but remained unchanged in pulmonary lymph. The difference between plasma colloid osmotic pressure and pulmonary artery wedge pressure decreased from 15.3 +/- 1.9 to -0.7 +/- 2.9 mm Hg. Despite this increase in filtration force, the lungs were protected from edema formation by a decrease of 11 mm Hg in pulmonary interstitial colloid osmotic pressure and a 7-fold increase in lymph flow. (+info)
Fas gene mutation in the progression of adult T cell leukemia.
Fas antigen (Apo-1/CD95) is an apoptosis-signaling cell surface receptor belonging to the tumor necrosis factor receptor superfamily. Adult T cell leukemia (ATL) cells express Fas antigen and show apoptosis after treatment with an anti-Fas monoclonal antibody. We established the ATL cell line KOB, which showed resistance to Fas-mediated apoptosis, and found that KOB expressed two forms of Fas mRNA, the normal form and a truncated form. The truncated transcript lacked 20 base pairs at exon 9, resulting in a frame shift and the generation of a premature stop codon at amino acid 239. The same mutation was detected in primary ascitic cells and peripheral blood cells. The mutation was not detected in lymph node cells, however, although all of the primary ATL cells were of the same clonal origin. A retroviral-mediated gene transfer of the truncated Fas to Jurkat cells rendered the cells resistant to Fas-mediated apoptosis, suggesting a dominant negative interference mechanism. These results indicate that an ATL subclone acquires a Fas mutation in the lymph nodes, enabling the subclone to escape from apoptosis mediated by the Fas/Fas ligand system and proliferate in the body. Mutation of the Fas gene may be one of the mechanisms underlying the progression of ATL. (+info)
Effects of ursodeoxycholic acid on systemic, renal and forearm haemodynamics and sodium homoeostasis in cirrhotic patients with refractory ascites.
Systemic arterial vasodilatation has been implicated in the pathogenesis of sodium retention in cirrhosis. Hydrophobic bile acids, which have vasodilatory actions, may be involved. Ursodeoxycholic acid, a hydrophilic bile acid, could potentially decrease systemic arterial vasodilatation, possibly due to its antioxidant effects, and improve sodium handling in cirrhosis. The effects of ursodeoxycholic acid on systemic, renal and forearm haemodynamics, liver function and renal sodium handling were assessed in vasodilated cirrhotic patients with refractory ascites treated with a transjugular intrahepatic porto-systemic shunt (TIPS). Eight cirrhotic patients with refractory ascites without TIPS placement served as controls for the sodium handling effects of ursodeoxycholic acid. From 1 month post TIPS, seven patients were studied before, after 1 month of treatment with ursodeoxycholic acid (15 mg.day-1.kg-1) and at 1 month follow-up. Lipid peroxidation products were used as indices of its antioxidant effects. Ursodeoxycholic acid caused a significant reduction in sodium excretion in both groups (P<0.05). This, in the post-TIPS patients (urinary sodium excretion: 35+/-8 mmol/day at 1 month versus 93+/-21 mmol/day at baseline, P<0.05), was due to a significant increase in sodium reabsorption proximal to the distal tubule (P<0.05), without any significant changes in systemic, renal or forearm haemodynamics, or in liver function. No significant change in lipid peroxidation products was observed. We conclude that: (i) in cirrhotic patients with refractory ascites, ursodeoxycholic acid causes sodium retention, (ii) the abnormality in sodium handling in the post-TIPS cirrhotic patients appears to be the result of a direct effect on the proximal nephron, suggesting that factors other than systemic vasodilatation also contribute to sodium retention in cirrhosis, (iii) caution should be exercised in administering ursodeoxycholic acid in cirrhotic patients with ascites. (+info)
Expression of phosphatidylethanolamine N-methyltransferase in Yoshida ascites hepatoma cells and the livers of host rats.
Previous studies have implicated phosphatidylethanolamine N-methyltransferase-2 (PEMT2) in the regulation of non-neoplastic liver growth [Tessitore,L., Cui,Z. and Vance,E. (1997) Biochem. J., 322, 151-154]. We have now investigated whether or not PEMT2 is also involved in the control of proliferation of hepatoma cells growing in an animal and cell death by apoptosis in the liver of tumor-bearing rats. PEMT activity was barely detectable and PEMT2 protein was absent in hepatoma cells growing exponentially in vivo whereas CTP:phosphocholine cytidylyltransferase (CT) activity and expression were high. The lack of PEMT2 corresponded with the absence of its mRNA. Both PEMT2 protein and mRNA appeared when cells entered the stationary phase of tumor growth and, in parallel, CT expression decreased. The host liver first became hyperplastic and exhibited a slight increase in CT activity and decrease in PEMT2 expression. During the stationary phase of hepatoma growth the host liver regressed and eventually became hypoplastic following induction of apoptosis. The appearance of apoptosis in the host liver was associated with a marked reduction in both CT activity and expression as well as an enhancement of PEMT activity and PEMT2 expression. McArdle RH7777 hepatoma cells underwent apoptosis when transfected with cDNA for PEMT2. The evidence supports the proposal that PEMT2 may have a role in the regulation of 'in vivo' hepatoma and hepatocyte cell division as well as hepatocyte cell death by apoptosis. (+info)