Effects of recombinant drug-specific single chain antibody Fv fragment on [3H]-desipramine distribution in rats

Tricyclic antidepressant overdose can be reversed in rats by drug-specific antibody Fab fragments, but the required Fab dose may itself by toxic. We studied the potential use of a smaller, recombinant desipramine (DMI)-specific single chain Fv fragment (B9-sFv) for this purpose. Anesthetized rats received a tracer (subtoxic) dose of [3H]-DMI followed in 15 min by B9-IgG, B9-Fab, B9-sFv (0.1 mumol of binding sites) or BSA. Each of the active treatments produced a rapid and substantial increase in the serum radiolabel concentration, whereas BSA did not (P < 0.001). The increase in serum radiolabel concentration 1 min after treatment was 13.3-fold with B9-IgG, 10.0-fold with B9-Fab and 7.3-fold with B9-sFv. Serum antibody concentrations were also highest after B9-IgG and lower with B9-Fab or B9-sFv. The 24-hr urinary excretion of radiolabel did not differ among groups, but was extensive even in the BSA group and probably represented the excretion of DMI metabolites. B9-sFv concentrations in urine or buffer at 37 degrees declined by >90% over 24 hr, but this fragment was much more stable in serum, retaining 70% of its activity after 96 hr. These data demonstrate that B9-sFv can alter markedly the distribution of [3H]-DMI in vivo. The rapidity of this effect, and its magnitude in comparison with Fab fragment or IgG, suggest that further study of B9-sFv as a treatment of DMI overdose is warranted.

Urinary metabolic profile in rat of 1-(2-methoxyphenyl)-2-methyl-2-(3-pyridyl)-1-propanone: a potential radioligand for functional diagnosis of adrenal pathology

1. The metabolism of 1-(2-methoxyphenyl)-2-methyl-2-(3-pyridyl)-1-propanone (2-MPMP) was studied in the male Sprague-Dawley rat after 50 mg/kg, i.v. dose. 2. Organic solvent extracts of urine samples were directly analysed by reversed-phase gradient hplc. The identified metabolites were also isolated by preparative tlc, and analyzed by direct probe mass spectrometry. In the case of conjugated metabolites, the urine samples were deconjugated by enzyme hydrolysis prior to extraction. The structures of metabolites were confirmed by comparison of their chromatographic behaviours, UV spectra, and mass spectra with those of authentic standards. 3. The metabolites identified in the 0-24-h urine samples were 2-hydroxyphenyl-metyrapone (2-OHPMP) and 2-hydroyphenylmetyrapone N-oxide (2-OHPMP-NO), which were present predominantly as their glucuronide and/or sulphate conjugates. 4. 2-MPMP and four of its metabolites present in the 0-24-h urine samples were quantified by a reversed-phase hplc method. The mean total urinary excretion was 75.4% of the administered dose. The major metabolites present in the urine were conjugates of 2-OHPMP-NO (54.4%) and of 2-OHPMP (18.6%). The excretion of the unchanged drug, unconjugated 2-OHPMP and 2-OHPMP-NO accounted for 1.1, 1.1 and 0.2% of the dose respectively.

Puqiedinone, a novel 5 alpha-cevanine alkaloid from the bulbs of Fritillaria puqiensis, an antitussive traditional Chinese medicine

A novel 5 alpha-cevanine alkaloid, puqiedinone [1], was isolated from the bulbs of Fritillaria puqiensis, a traditional Chinese medicine used widely for its antitussive and expectorant properties. The structure of 1 was assigned as (20R,22S,25R)-20-deoxy-5 alpha-cevanine-3 beta-ol-6-one based on spectral analysis and comparison with the structures of related known compounds. Puqietinone [2] was also identified from the same herbal plant and the structure was revised as (22R,25S)-N-methyl-22,26-epiminocholest-3 beta-ol-6-one based on spectroscopic and X-ray crystallographic methods.

Effects of pesticides on the ratio of 16 alpha/2-hydroxyestrone: a biologic marker of breast cancer risk

Xenobiotic estrogens are external compounds with estrogenic activity that may thereby affect the risk of breast cancer. This paper describes a mechanism by which xeno-estrogens may affect the development of breast cancer. Estradiol metabolism proceeds by hydroxylation at one of two mutually exclusive sites at C-2 and C-16 alpha. The catechol pathway yields the weakly estrogenic 2-hydroxyestrone (2-OHE1), which inhibits breast cell proliferation. In contrast, the alternative pathway yields the genotoxic 16 alpha-hydroxyestrone (16 alpha-OHE1), which enhances breast cell growth, increases unscheduled DNA synthesis, and oncogene and virus expression, and increases anchorage-independent growth. Using a radiometric assay that measures the relative formation of 16 alpha-OHE1 versus 2-OHE1 from specifically tritiated estradiol in (ER+) MCF-7 cells, we compared the ratio of 16 alpha-OHE1/2-OHE1 observed after treatment with the known rodent carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) with the ratios after treatment with DDT, atrazine, gamma-benzene hexachloride, kepone, coplanar PCBs, endosulfans I and II, linoleic and eicosapentenoic acids, and indole-3-carbinol (I3C). These pesticides significantly increase the ratio of 16 alpha-OHE1/2-OHE1 metabolites to values comparable to or greater than those observed after DMBA. In contrast, the antitumor agent I3C increased 2-OHE1 formation and yielded ratios that are 1/3 of those found in unexposed control cells and 1/10th of those found in DMBA-treated cells. Thus the ratio of 16 alpha-OHE1/2-OHE1 may provide a marker for the risk of breast cancer. Assays of this ratio, which can be measured in spot urines, may prove useful for a variety of in vitro and in vivo studies bearing on breast cancer risk.

Cloning, expression, and purification of an anti-desipramine single chain antibody in NS/O myeloma cells

Drug-specific monoclonal antibodies and their antigen-binding Fab fragments reverse acute desipramine toxicity in a rat experimental model by inducing a redistribution of drug from cardiac tissue into serum and extracellular fluid. In order to investigate the use of smaller recombinant antibody fragments such as single chain Fv (sFv) as an antidote, an efficient murine NS/O myeloma expression system was developed. The variable light (VL) and variable heavy (VH) domains of a murine anti-desipramine monoclonal antibody were cloned and sequenced. A 270 amino acid VH-(Gly4Ser)3-VL sFv was prepared by overlapping polymerase chain reaction (PCR) amplification of VH with heavy chain leader peptide, VL, and the linker. This construct was subcloned into a mammalian expression vector which utilizes the SR alpha promoter, a hybrid promoter consisting of the SV40 early promoter with portions of the human T-cell leukemia virus type I long terminal repeat and also containing the Escherichia cloi xanthine-guanine phosphoribosyltransferase gene for selection. NS/O myeloma cells were transfected by electroporation. Stable recombinant NS/O clones were screened for expression of sFv using reverse transcriptase-PCR to detect mRNA and an enzyme-linked immunosorbent assay (ELISA) to detect sFv. Secreted sFv from clones capable of growth to a cell density of 2-4 x 10(6) viable cells/mL was purified in a single step using a desipramine affinity column resulting in 12-39 mg/L of purified sFv. Affinity-purified sFv had comparable desipramine binding activity to Fab when evaluated by competitive ELISA.

Expression of CD34 in endothelial cells, hematopoietic progenitors and nervous cells in fetal and adult mouse tissues

The human cell surface molecule CD34 is selectively expressed on uncommitted and committed hematopoietic progenitor cells and on vascular endothelial cells. It has been suggested that CD34 regulates early events in blood cell migration and differentiation, possibly as a cell adhesion molecule. To characterize the patterns of expression of CD34 in the mouse embryo and in the adult, as well as to dissect the function of different portions of the extracellular domain of this molecule, we have generated the first monoclonal antibodies (mAb) specific for mouse CD34. The epitope(s) recognized by these mAb are not carbohydrate moieties, and are comprised either within the immunoglobulin-like domain or within a portion of the mucin domain, containing approximately half of the predicted O- and N-linked carbohydrate attachment sites. The specificity of the antibodies was established by ELISA and Western blotting. Western analysis revealed that these mAb recognize a protein of approximately 110 kDa in PA6 stromal cell lysates, which can be specifically blocked by the recombinant CD34 protein. To establish the reactivity of these mAb on different cell lineages, a panel of cell lines was stained. This analysis showed strong reactivities with 3T3 fibroblasts, stromal cell lines from fetal liver and with the endothelial cell line D10. Bone marrow hematopoietic progenitors were also stained by these mAb. Immunostaining of frozen sections from embryonic and adult tissues revealed a strong reactivity against vascular endothelial cells at different stages of development, including sinusoidal cells in the fetal liver, yolk sac, and in the fetal bone marrow, endothelial cells from adult lung and kidney, and neural cells, including those of the neural tube of midgestation embryos and neuronal bodies in adult brain.

The fate of long-standing intraperitoneal gallstone in the rat

Gallstones are occasionally spilled into the peritoneal cavity during open and laparoscopic cholecystectomy. Using the rat model, we investigated the long term effect of such retained intraperitoneal gallstones. During a follow-up period of one year, no systemic deleterious outcome could be attributed to the presence of the implanted gallstones except for mild local effects. Based on the rat model we conclude that reasonable effort should be made in order to retrieve an escaped gallstone, but there is no justification whatsoever for a conversion of the laparoscopic procedure to an open laparotomy only for the purpose of retrieving a lost stone.

Effects of interleukin-1 and interleukin-1 receptor antagonist in AIDS-Kaposi's sarcoma

Kaposi's sarcoma (KS) is the most common tumor seen in patients with HIV-1 infection. HIV-1 may induce KS directly through viral protein(s) or indirectly through regulation of cytokines such as IL-1 and IL-6. We have shown that AIDS-KS spindle cells express IL-1 beta and that IL-1ra inhibits KS-spindle cell growth. IL-1ra had little effect on human umbilical vein endothelial cells (HUVEC), human aortic smooth muscle cells (HASM), and human foreskin fibroblast (NN41). These findings support an autocrine activity for IL-1. Furthermore, exogenous IL-1 can enhance AIDS-KS cell growth, and this effect is completely blocked by IL-1ra. As expected, IL-1ra also blocks IL-1 mediated upregulation of IL-6 and bFGF, both of which are autocrine growth factors for KS. IL-1ra is thus a potential candidate for the treatment of AIDS-associated KS.

Comparison of serum C-reactive protein concentrations for laparoscopic versus open cholecystectomy

In an attempt to quantify the difference in tissue damage between open cholecystectomy (OC) and laparoscopic cholecystectomy (LC), we have compared in a prospective manner the pre- and post-operative concentrations of serum C-reactive protein (CRP) in 17 patients undergoing LC and 13 patients undergoing OC. In addition, we measured the pre- and postoperative white blood cell counts (WBC), the postoperative body temperature, and the postoperative duration of hospitalization. There were no differences in the preoperative serum CRP concentrations--5.9 +/- 2.62 mg/l (mean +/- SD) for the LC group and 6.12 +/- 2.38 mg/l for the OC group. Serum CRP rose markedly following OC compared to that of patients who underwent LC (128.6 +/- 45.1 mg/l vs 26.8 +/- 10.5 mg/l) (P < 0.001). There were also significant differences in the postoperative WBC count (14,000 +/- 2,900 cells for the OC group vs 10,600 +/- 3,000 cells for the LC group), the postoperative body temperature (37.5 +/- 0.3 degrees C vs 37.0 +/- 0.3 degrees C), and the postoperative hospital stay (5.5 +/- 1.5 days vs 1.9 +/- 0.9 days). There was no correlation between serum CRP concentrations and the other postoperative parameters. These results provide us with biochemical evidence supporting the clinical observation that LC is far less traumatic to the patient than OC.

Interleukin-4 suppresses the expression of macrophage NADPH oxidase heavy chain subunit (gp91-phox)

The production of superoxide anion by NADPH oxidase is a principal nonspecific bactericidal activity of macrophages and neutrophils in host defense. However, exuberant production of superoxide anion also damages host tissues. Cloning and DNA sequencing of the 91 kDa subunit (gp91-phox) open reading frame indicated a high degree of sequence conservation, greater than 90% in nucleotide and amino acid sequences, between the porcine and human cDNAs. We show in pigs that interleukin-4 (IL-4), a T lymphocyte cytokine which plays a major role in mediating antibody responses to pathogens, suppresses superoxide anion production in macrophages by specifically reducing the level of mRNA encoding gp91-phox. Messenger RNA levels are suppressed approx. 70% within 4 h and persist for 24 h without any change in the rate of mRNA turnover. Nuclear run-on analysis showed that IL-4 did not alter the rate of gp91-phox gene transcription under conditions in which IL-1 beta transcription was inhibited. These results indicate that IL-4 suppresses the inflammatory response of macrophages by mechanisms that include post-transcriptional regulation of the 91 kDa catalytic subunit of NADPH oxidase, and transcriptional regulation of inflammatory cytokine expression.

Induction of inflammatory cytokines in bovine alveolar macrophages following stimulation with Pasteurella haemolytica lipopolysaccharide

Bovine tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) cDNAs were generated by reverse transcription and then by PCR amplification from lipopolysaccharide (LPS)-stimulated alveolar macrophage RNA. The amplified cDNAs were cloned into pPow and expressed in Escherichia coli DH5 alpha. The expressed proteins were confirmed as TNF-alpha and IL-1 beta by Western blot (immunoblot) analysis and bioassays. We then used the cloned genes as probes in Northern (RNA) blots and investigated the kinetics of TNF-alpha and IL-1 beta mRNA expression in bovine alveolar macrophages stimulated with purified LPS from Pasteurella haemolytica 12296. The effect of LPS on TNF-alpha and IL-1 beta gene expression was dose dependent, and induction was observed at a concentration of 0.01 microgram/ml. Both TNF-alpha and IL-1 beta mRNA expression were detectable within 0.5 h after stimulation with 1 microgram of LPS per ml, peaked at 1 to 2 h, steadily declined up to 16 h, and were undetectable by 24 h. Secreted TNF-alpha measured by bioassay peaked at 4 h and accumulated at a lesser concentration in conditioned medium throughout the 24 h. By contrast, secreted IL-1 beta was induced at 8 h and reached a maximal concentration at 24 h after stimulation. The ability of LPS to induce TNF-alpha and IL-1 beta gene expression and secretion of bioactive proteins were suppressed by polymyxin B. Our findings support a role for LPS from P. haemolytica in the induction of inflammatory cytokines in bovine pneumonic pasteurellosis.

Comparison of personality traits of only and sibling school children in Beijing

The number of only children in China has increased rapidly since the late 1970s, when the Chinese government advocated the "one-child-per-family" policy. This increase has caused much public concern about the healthy growth of the young generation. In this study the behavioral traits of Chinese, urban, only children were investigated. The participants were 444 children with siblings and 473 only children from Grades 1, 3, and 5 in Beijing primary schools. An inventory consisting of 27 items covering three behavioral traits was developed. The children were rated on the inventory by the principal teacher of the class. Factor analysis revealed three main factors: achievement motivation, interpersonal skills, and attitude toward manual labor. The only children exceeded the sibling children on achievement motivation. No differences were found between only children and sibling children on interpersonal skills and attitude toward manual labor. Gender differences were evident; girls consistently received higher ratings on achievement motivation and interpersonal skills. The possible underlying reasons for these differences are discussed.

Structures of human and porcine aldehyde reductase: an enzyme implicated in diabetic complications

The crystal structures of porcine and human aldehyde reductase, an enzyme implicated in complications of diabetes, have been determined by X-ray diffraction methods. The crystallographic R factor for the refined porcine aldehyde reductase model is 0.19 at 2.8 A resolution. There are two molecules in the asymmetric unit related by a local non-crystallographic twofold axis. The human aldehyde reductase model has been refined to an R factor of 0.21 at 2.48 A resolution. The amino-acid sequence of porcine aldehyde reductase revealed a remarkable homology with human aldehyde reductase. The coenzyme-binding site residues are conserved and adopt similar conformations in human and porcine aldehyde reductase apo-enzymes. The tertiary structures of aldhyde reductase and aldose reductase are similar and consist of a beta/alpha-barrel, with the coenzyme-binding site located at the carboxy-terminus end of the strands of the barrel. The crystal structure of porcine and human aldehyde reductase should allow in vitro mutagenesis to elucidate the mechanism of action for this enzyme and facilitate the effective design of specific inhibitors.

Interleukin-4 suppresses inflammatory cytokine gene transcription in porcine macrophages

Inflammatory cytokines, including interleukin (IL)-1 alpha, IL-1 beta, IL-8, and tumor necrosis factor alpha (TNF-alpha) are produced by macrophages in response to a variety of pathogenic stimuli. We show here that the expression of inflammatory cytokines is suppressed by IL-4 at the transcriptional level. Interleukin-4, when added together with bacterial lipopolysaccharide (LPS), suppressed LPS-induced increases in mRNA levels of IL-1 alpha, IL-1 beta, IL-8, and TNF-alpha in alveolar macrophages. The level of suppression was dependent on dose and time of exposure and reached a maximum of 75-80% of uninduced values for IL-1 alpha, IL-8, and TNF. Interleukin-1 beta expression was completely inhibited by IL-4. The amount of secreted protein, as determined by TNF-alpha bioassay, was also suppressed by IL-4. Half-maximal suppression occurred at IL-4 concentrations between 0.02 and 0.1 ng/ml for all inflammatory cytokines. Nuclear run-on assays showed that IL-4 suppressed transcriptional activity of all inflammatory cytokines. Messenger RNA stability was not changed by IL-4. The data suggest that IL-4 plays an important transcriptional role in the regulation of alveolar macrophage inflammatory activities in respiratory disease and raise the possibility that IL-4 may function in vivo as a coordinator of inflammatory and immune responses.

Decomposition of clozapine N-oxide in the qualitative and quantitative analysis of clozapine and its metabolites

Pooled plasma from healthy volunteers was spiked with pure, synthetic clozapine or clozapine N-oxide and then made alkaline with either sodium hydroxide or sodium carbonate. The alkalized samples were allowed to stand at room temperature for various time intervals before extraction with organic solvent and then analyzed by high-performance liquid chromatography. It was found that clozapine N-oxide was reduced to clozapine in plasma made alkaline with sodium hydroxide, but such reduction was negligible in the plasma made alkaline with sodium carbonate. The amount of clozapine produced from clozapine N-oxide depended upon both the strength of the alkali added to the plasma and the duration of exposure of the plasma proteins plus clozapine N-oxide to the alkali. The reduction appears to take place through reducing equivalents generated by the action of strong alkali on plasma proteins. The thermal lability of clozapine N-oxide during gas chromatography-mass spectrometric analysis was also investigated. It was found that clozapine N-oxide was quantitatively decomposed to clozapine during gas chromatography-mass spectrometric analysis.

Expression and characterization of cM-T413, a chimeric anti-CD4 antibody with in vitro immunosuppressive activity

Anti-CD4 monoclonal antibodies (mAbs) have shown considerable promise in the treatment of rheumatoid arthritis, psoriasis, and allograft rejection and may have potential use in blocking HIV-1 infection. One such anti-CD4 mAb we have developed, chimeric M-T412 (or cM-T412), has been used in clinical trials to treat rheumatoid arthritis, generalized postular psoriasis, and other autoimmune diseases. Here we report the cloning and expression of a second chimeric anti-CD4 mAb using M-T413, a murine mAb that blocks HIV-1 infection of H9 cells. We cloned the immunoglobulin light and heavy chain variable regions of M-T413, combined them with the human kappa (light chain) or G1, G2, G3 and G4 (heavy chain) constant regions in human expression vectors, and expressed these chimeric mAbs in 653 cells. Like chimeric M-T412 IgG1, the chimeric M-T413 mAbs inhibit T-cell proliferation in the mixed lymphocyte response and thus can act to immunosuppress CD4+ T-cell response. In contrast to M-T412, however, the M-T413 chimeric mAbs have reduced activity in an antibody-dependent cell-mediated cytotoxicity (ADCC) assay using human CD4+ target and effector cells. We conclude that the chimeric M-T413 mAbs have potential utility in treating autoimmune disease and may be useful as prophylactics in preventing HIV-1 infection.

Differentiation of two classes of "A" system amino acid transporters

Injection of mRNA from GF-14 cells (a mouse lymphocyte cell line) into Xenopus oocytes led to the expression of a transport activity characteristic of amino acid transport system A, i.e., Na+ dependent and recognizing aminoisobutyric acid and its methyl derivative (AIB and meAIB). Sucrose density gradient fractionation of GF-14 mRNA showed that the maximum level of expression of activity was associated with a 2.2-kb RNA fraction. Pretreatment of GF-14 cells with insulin caused a twofold increase in system A transport activity in the cells themselves and the mRNA from the insulin-treated cells induced a comparable increase in A system transport over control mRNA when expressed in oocytes. mRNA from cells treated with insulin in presence of actinomycin D did not show a response to insulin, suggesting that GF-14 cells synthesized new transporter in response to insulin. Similar experiments with mRNA from the Ehrlich ascites cells, showed that expression of system A type transport was associated chiefly with a 4.2-kb mRNA fraction. Although insulin treatment of Ehrlich cells also caused an increase in A system transport activity in the cells themselves (nearly twofold), the response to insulin was not blocked by actinomycin D or cycloheximide. Moreover, mRNA from insulin-treated and untreated Ehrlich cells gave the same level of expression in oocytes of A type amino acid transport. In contrast to GF-14 cells, Western blots of plasma membranes showed that insulin treatment of Ehrlich cells increased the amount therein of a 120- to 130-kDa peptide, previously associated with amino acid transport (Proc. Natl. Acad. Sci. USA 85, 7877, 1988), suggesting that in the Ehrlich cells, but not in GF-14, cells this polypeptide was translocated from intracellular sites in response to insulin. The data associate two distinctly different responses to insulin with A-type amino acid transporters and are consistent with the existence of more than a single A type amino acid transporter in mouse cells.

Are elevated liver enzymes and bilirubin levels significant after laparoscopic cholecystectomy in the absence of bile duct injury?

OBJECTIVE

Increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin levels were noted incidentally after a laparoscopic cholecystectomy. The percentage in which such elevation occurs and its clinical significance in the absence of bile duct injury were investigated.

SUMMARY BACKGROUND DATA

Bile duct injury is the most feared complication of laparoscopic cholecystectomy. Some laboratory tests may be indicative of this complication, such as increases in liver enzyme (AST, ALT, and alkaline phosphatase [ALP]) and bilirubin. These parameters have not been investigated in patients who had laparoscopic cholecystectomy and in whom no damage to the bile duct was noted.

METHODS

Sixty-seven patients with normal results of preoperative liver function test were entered into the study. Blood was collected 24 hours after laparoscopic cholecystectomy, and AST, ALT, ALP, and bilirubin levels were measured.

RESULTS

A mean 1.8-fold increase in AST occurred in 73% of patients; 82% showed a 2.2-fold increase in ALT. A statistically nonsignificant increase was noted in 53% of patients (ALP remained within normal limits), and in 14% of patients bilirubin levels were increased (they were primarily of the unconjugated type).

CONCLUSIONS

In many patients a significant increase in AST and ALT levels occurred after laparoscopic cholecystectomy, but they returned to normal values within 72 hours. The cause of this is unclear, and these elevations appear to have no clinical significance.

[Surgery for acute arterial emboli to the arm]

During a 5-year period (1987-1992) we removed under local anesthesia 20 emboli and 2 thrombi from the arms of 18 patients aged 60-90 using a Fogarty catheter. 18 of the emboli (90%) were of cardiac origin. 1 patient had thrombosis of the axillary artery (2 episodes). The occlusions were brachial in 14 (70%), axillary in 5 (25%), and radial in 1. From 1.5 hours to 1 week elapsed between onset of symptoms and operation. 9 patients underwent arteriography. Surgery was successful in 19 (95%). Limb necrosis developed in a patient operated on 1 week after onset of symptoms. Necrosis progressed despite a palpable radial pulse. 33 patients (15%) died of causes unrelated to the operation: 2 had terminal cardiac disease and the third concomitant occlusion of the superior mesenteric artery. Early surgical exploration is advocated for acute arterial embolism of the upper extremity. Ischemic changes may be reversible even later than 24 hours from onset of symptoms. Routine arteriography is not needed before surgical exploration of these cases.

Regulation of interleukin-8 expression in porcine alveolar macrophages by bacterial lipopolysaccharide

Interleukin (IL)-8 is a macrophage-derived neutrophil chemotactic factor that plays an important role in the recruitment of neutrophils to inflammatory loci. Hence, expression of IL-8 by alveolar macrophages may be a significant factor in host defense in the lung and in the pathogenesis of pneumonia in swine. To initiate molecular studies of IL-8 regulation in pigs, we cloned IL-8 cDNA and examined the regulation of its mRNA in alveolar macrophages. The porcine IL-8 cDNA consists of 1491 base pairs including a coding region of 309 base pairs. The deduced amino acid sequence was 75 and 81% similar to human and rabbit IL-8, respectively. Resting macrophages contained low levels of IL-8 mRNA, which increased markedly after exposure to bacterial lipopolysaccharide (LPS). LPS induction of IL-8 was direct, not mediated through elevation of tumor necrosis factor or interleukin-1. The effect of LPS on IL-8 expression was dose dependent, and induction was observed at a concentration of 10 pg/ml. IL-8 mRNA expression was detectable within 0.5 h after stimulation with LPS, peaked at 3-6 h at about 30-fold higher levels than in resting cells, and was maintained for 24 h. Secreted IL-8, measured by neutrophil chemotaxis, was induced within 4 h by LPS, and accumulated in the media throughout the 24-h period. The mechanism of induction of IL-8 mRNA appeared to involve transcription and RNA processing. Nuclear run-on analysis showed that the IL-8 gene was actively transcribed in noninduced cells; upon stimulation with LPS, the rate of IL-8 transcription was increased about 4-fold. A single mature mRNA species was detected by primer extension analysis. The half-life of IL-8 mRNA transcripts in aveolar macrophages was approximately 2 h and did not change after LPS stimulation. The ability of LPS to induce IL-8 expression was suppressed by recombinant human IL-4 and dexamethasone in a concentration-dependent manner. These observations indicate that the expression of IL-8 is an early event in the sequelae to bacterial infection in the lung.

Oligohydramnios: maternal complications and fetal outcome in 145 cases

One hundred and forty-five cases of oligohydramnios in the second and third trimester were diagnosed by ultrasonography out of 25,000 obstetrics patients (0.58%). In this group, pregnancy complications included hypertension (22.1%) and bleeding in the second trimester (4.1%). We found a high incidence of meconium-stained amniotic fluid (29.1%), fetal distress (7.9%) and premature placental separation (4.2%). IUGR occurred in 24.5% of cases. Asphyxia during labor occurred in 11.5% and different other perinatal problems in 23.5%. Cesarean section was performed in 35.2% of these pregnancies. Seventeen percent of the cases presented as breech. Intrauterine fetal death occurred in 5.5% of these pregnancies. The gross perinatal mortality was 16% and the corrected perinatal mortality was 10.7%. The overall rate of fetal malformations was 11% and that of lethal malformations 4.8%. The skeletal (7.6%) and urinary system (4.1%) were the predominant systems affected. Oligohydramnios is associated with a higher rate of pregnancy complications and increased fetal morbidity and mortality, and thus termination should be considered when pulmonary maturity is present or in cases of fetal distress.

An experimental study and clinical pilot trials on yttrium-90 glass microspheres through the hepatic artery for treatment of primary liver cancer

BACKGROUND

Yttrium-90 (90-Y) glass microsphere is a new kind of radiation microsphere for internal radiation therapy of primary liver cancer (PLC). The study was carried out by administration of 35 microns nondegradable 90-Y glass microsphere through the hepatic artery for treatment of PLC.

METHODS

Six rabbits were injected with 185-1480 megabecquerels (MBq) of 90-Y glass microspheres, and three rabbits were injected with 35-300 mg of 89-Y glass microspheres for the toxic test. Eighteen patients received 2442-5550 MBq of 90-Y glass microspheres for the treatment of PLC. Whole blood counts, liver function, and imaging examination were performed. Pathologic examinations were performed on all rabbits.

RESULTS

All rabbits were apparently well after absorbing 114.1-845.2 Gy 90-Y glass microspheres in the liver but showed transient degeneration of hepatocytes and portal fibrosis histologically. The mean absorbed dose in liver tissue of patients with PLC was 30.33 Gy, whereas that in tumor tissue was 88 Gy and the highest in tumor tissue, 186.36 Gy. The mean tumor:liver tissue ratio was 3:1; the highest, 14:1. Fourteen patients were still alive after half a year's follow-up and 6 of these 14 were still alive after 1 year.

CONCLUSIONS

The rabbits could tolerate up to eight-fold of the upper limit of clinical dose (100 Gy). Good responses to the radiation therapy of 90-Y glass microspheres in patients with localized and hypervascular or vascular mass were achieved. Contraindications for the therapy were presence of massive hepatic arterioportal shunt and cancer emboli in the main portal vein. It is safe and applicable to deliver 90-Y glass microspheres in large doses through the hepatic artery for internal radiation treatment of PLC.

An experimental study and clinical pilot trials on yttrium-90 glass microspheres through the hepatic artery for treatment of primary liver cancer

BACKGROUND

Yttrium-90 (90-Y) glass microsphere is a new kind of radiation microsphere for internal radiation therapy of primary liver cancer (PLC). The study was carried out by administration of 35 microns nondegradable 90-Y glass microsphere through the hepatic artery for treatment of PLC.

METHODS

Six rabbits were injected with 185-1480 megabecquerels (MBq) of 90-Y glass microspheres, and three rabbits were injected with 35-300 mg of 89-Y glass microspheres for the toxic test. Eighteen patients received 2442-5550 MBq of 90-Y glass microspheres for the treatment of PLC. Whole blood counts, liver function, and imaging examination were performed. Pathologic examinations were performed on all rabbits.

RESULTS

All rabbits were apparently well after absorbing 114.1-845.2 Gy 90-Y glass microspheres in the liver but showed transient degeneration of hepatocytes and portal fibrosis histologically. The mean absorbed dose in liver tissue of patients with PLC was 30.33 Gy, whereas that in tumor tissue was 88 Gy and the highest in tumor tissue, 186.36 Gy. The mean tumor:liver tissue ratio was 3:1; the highest, 14:1. Fourteen patients were still alive after half a year's follow-up and 6 of these 14 were still alive after 1 year.

CONCLUSIONS

The rabbits could tolerate up to eight-fold of the upper limit of clinical dose (100 Gy). Good responses to the radiation therapy of 90-Y glass microspheres in patients with localized and hypervascular or vascular mass were achieved. Contraindications for the therapy were presence of massive hepatic arterioportal shunt and cancer emboli in the main portal vein. It is safe and applicable to deliver 90-Y glass microspheres in large doses through the hepatic artery for internal radiation treatment of PLC.

Metabolism of piperidine-type phenothiazine antipsychotic agents. IV. Thioridazine in dog, man and rat

1. The metabolism of thioridazine was studied in adult male volunteers, female rat and female dog after oral administration of 50 mg, 20 mg/kg and 100 mg over 30 h, respectively. 2. Metabolites in organic extracts of the urine obtained from each species were analysed by plasmaspray h.p.l.c.-mass spectrometry. For phenolic metabolites the crude extracts from each species were derivatized with a silylating reagent (with and without prior enzymic hydrolysis) prior to h.p.l.c.-mass spectrometric analysis. The structures of metabolites, with the exception of phenols, were confirmed by comparison of their chromatographic behaviours and mass spectral data with those of authentic standards. 3. The metabolites identified in the urine of all three species were mesoridazine, sulforidazine, thioridazine ring sulphoxide, mesoridazine ring sulphoxide, sulforidazine ring sulphoxide, the lactam of mesoridazine ring sulphoxide and unconjugated phenolic derivatives of mesoridazine and sulforidazine. Other compounds observed were: unchanged thioridazine (dog, rat), sulforidazine N-oxide (man), N-desmethylthioridazine ring sulphoxide (dog, rat), N-desmethylmesoridazine ring sulphoxide (dog, rat), the lactam of sulforidazine ring sulphoxide (rat, man), phenolic derivative of thioridazine in unconjugated form (rat), and conjugated form (man), and conjugated phenolic derivative of mesoridazine (man). 4. Thioridazine and six of its metabolites present in the urine of man, rat and dog were quantified by a h.p.l.c.-UV procedure. The mean total urinary excretion (+/- SD) of the measured analytes in man, rat and dog were determined to be 4.3 +/- 2.9, 4.8 +/- 1.7 and 12.1 +/- 5.4% of the dose, respectively. The mean excretion of the lactam of mesoridazine ring sulphoxide was greater in man (1.2 +/- 1.0%) and rat (0.2 +/- 0.2%) than dog (< 0.02%). Moreover, the mean excretion of the lactam of sulforidazine ring sulphoxide was quantifiable in both man (0.5 +/- 0.4%) and rat (0.2 +/- 0.2%). 5. Interspecies comparison of the lactam metabolites indicated that both qualitatively and quantitatively, man more closely resembled rat than dog. Similar observations were previously reported for mesoridazine and sulforidazine, therefore rat may be a more suitable animal than dog to undertake further study of the importance of C-oxidation of the piperidine ring of this class of drug.

Enhanced detection of intracellular organism of swine proliferative enteritis, ileal symbiont intracellularis, in feces by polymerase chain reaction

A sensitive assay based on amplification of a 319-bp DNA fragment of the intracellular bacterium of swine proliferative enteritis was developed for the detection of the organism in the feces of swine. A vernacular name, ileal symbiont intracellularis (IS-intracellularis), has recently been published for the intracellular bacterium, which was formerly known as a Campylobacter-like organism (C.J. Gebhart, S.M. Barnes, S. McOrist, G.F. Lin, and G.H.K. Larson, Int. J. Syst. Bacteriol. 43:533-538, 1993). As few as 10(1) IS-intracellularis organisms purified from intestinal mucosa, or 10(3) IS-intracellularis per g of feces, were detected. No amplification product was produced from a polymerase chain reaction performed on DNA extracted from the feces of healthy pigs. A 319-bp DNA fragment specific for IS-intracellularis was produced on amplification of DNA from the feces of pigs with experimental and naturally occurring proliferative enteritis.

Experimental studies of portal venous embolization with iodized oil in rats with experimentally induced liver cancer

PURPOSE

To assess the feasibility of portal venous embolization (PVE) with iodized oil in the treatment of human hepatocellular carcinoma (HCC), the distribution of iodized oil after PVE and tumor vascularity after hepatic arterial embolization (HAE) with iodized oil was determined in 25 rats with n-nitrosodiethylamine-induced liver cancer.

MATERIALS AND METHODS

Under microscopic guidance, HAE with 1 mL of iodized oil was performed in 10 rats. After HAE, low-kilovoltage radiography in four rats and Microfil perfusion techniques in six were used to investigate the distribution of iodized oil and the portal blood supply, respectively. Low-kilovoltage radiography and histologic examination were performed to observe the distribution of iodized oil in 15 rats after PVE with doses of 0.6 mL/kg in each rat.

RESULTS

After HAE with iodized oil, it was common that tumor nodules smaller than 5 mm in diameter were filled with Microfil perfused through the portal vein. After PVE, tumor nodules (< 5 mm) were completely filled with iodized oil, while filling defects were observed in larger tumor nodules (> 5 mm), which could have been filled through hepatic arterial perfusion.

CONCLUSION

PVE with iodized oil may have a role in the treatment of hepatic malignant tumors, and it may play an important role in early detection and treatment of small tumor nodules (< 5 mm) supplied mainly by the portal vein.

Cloning, sequencing and regulation of an mRNA encoding porcine interleukin-1 beta

Interleukin 1 (IL-1) is a cytokine that mediates a variety of immunological responses. We report here the isolation of a porcine IL-1 beta cDNA from an alveolar macrophage library. The complete cDNA sequence is 1458 bp in length and has an open reading frame of 803 bp, encoding a 267-amino-acid (aa) protein with an approximate molecular size of 31 kDa. The porcine IL-1 beta cDNA sequence shows homologies of 82.0, 81.0, 74.0, and 74.0% with the bovine, sheep, human, and murine sequences in the protein coding regions, respectively. Northern blot analysis reveals a single 1.7-kb mRNA species that is differentially regulated by lipopolysaccharide, phorbol myristate acetate, and tumor necrosis factor but is not regulated by human recombinant IL-1. Porcine IL-1 beta is down-regulated by dexamethasone, polymyxin B, and IL-4 in a fashion kinetically similar to the other reported species.

Yttrium-90 glass microspheres injected via the portal vein. An experimental study

Nondegradable glass microspheres (35 mu) were injected into the portal vein for toxicity test in 15 rabbits. In 10 animals the microspheres were loaded with 90Y, giving liver absorbed doses between 24.6 and 437.4 Gy, and in 5 with 89Y (control group). The total amount of microspheres injected in each animal varied between 35 and 140 mg. The rabbits in the experimental group tolerated the effect of radioembolization in a dose 4 times higher than the upper limit of the clinical dose (100 Gy). After injection of 90Y glass microspheres into the portal vein of rats with diethylnitrosamine (DEN)-induced hepatic carcinoma, the microspheres, in addition to the liver parenchyma, accumulated in central and peripheral parts of the cancer nodules, causing necrosis. The internal radiation therapy of 90Y glass microspheres delivered via the portal vein may be an effective nonsurgical method for the treatment of liver cancer, especially in small nodules.

The 0.25-nm X-ray structure of the Bowman-Birk-type inhibitor from mung bean in ternary complex with porcine trypsin

The structure of the Bowman-Birk-type inhibitor from mung bean Phaseolus aureus has been determined in ternary complex with porcine trypsin. The complex formed crystals of the trigonal space group P3(1)21 which diffracted to a resolution of 250 pm. Each of the two mung bean protease reactive sites is bound to trypsin according to the standard mechanism for serine proteinase inhibition. The binding loops thereby adopt the canonical conformation for the standard mechanism; however, the sub-van der Waals contact between the active-site serine O gamma (195) and the P1 carbonyl carbon of both loops is significantly smaller (210 pm) than hitherto observed, with continuous electron density connecting the two atoms. The inhibitor is formed by two double-stranded antiparallel beta-sheets, which are connected into a moderately twisted beta-sheet by a network of hydrogen bonds involving main-chain atoms and two water molecules. All contacts with neighbors in the crystal lattice occur between trypsin molecules. This apparently gives rise to an unusual form of disorder where the complexes pack in two orientations Ta:MaMb:Tb and Tb:MbMa:Ta (Ta, Tb = trypsin, Ma = mung bean loop I, Mb = mung bean loop II), such that the asymmetric unit consists of the ternary complex in two orientations, each with half occupancy. This is nearly equivalent to an asymmetric unit which has one trypsin molecule with full occupancy and one mung bean inhibitor with half occupancy and a crystallographic twofold symmetry axis through its center. Because of the approximate twofold symmetry of the inhibitor itself, however, the electron density was interpretable for most of the inhibitor (17 residues at the termini were not resolved) and shows evidence of its double orientation.

Synthesis of the N-oxides of phenothiazine antipsychotic agents

Chlorpromazine N-oxide, fluphenazine N4'-oxide, prochlorperazine N4'-oxide, sulforidazine N-oxide, and trifluoperazine N4'-oxide were synthesized by oxidation of the designated nitrogen atom in the N-10 side chain of the respective parent drug with 3-chloroperoxybenzoic acid. In the case of trifluoperazine, a stepwise increase in the amount of oxidant yielded the N1',N4'-dioxide and N1',N4',S-trioxide. The N',S-dioxides of chlorpromazine and sulforidazine were obtained by hydrogen peroxide oxidation of the appropriate parent drug.

The metabolism of piperidine-type phenothiazine antipsychotic agents. III. Mesoridazine in dog, human and rat

1. The metabolism of mesoridazine was studied in female rats (20 mg/kg, oral), female dogs (50 mg over 30 h, oral) and adult male volunteers (25 mg, oral). 2. Solvent extracts of urines from each species were directly analysed by h.p.l.c.-mass spectrometry with a plasmaspray interface. In the case of phenolic metabolites the urinary extracts were derivatized with a silylating reagent (with and without prior enzymic hydrolysis) prior to analysis. The structures of metabolites, with the exceptions of mesoridazine N-oxide and phenols, were confirmed by comparison of their chromatographic behaviours and mass spectra with those of authentic standards. 3. Compounds identified in the urine of all three species were mesoridazine, sulforidazine, mesoridazine ring sulphoxide, sulforidazine ring sulphoxide, N-desmethylmesoridazine ring sulphoxide, the lactam of sulforidazine ring sulphoxide and phenolic derivatives of mesoridazine and sulforidazine. Whereas the unconjugated phenolic metabolite of sulforidazine was present in urine of all three species, the conjugated form was identified only in dog and rat urines. Also, the unconjugated phenolic metabolite of mesoridazine was identified only in the urine of dog and human, but rat urine contained only the conjugated form. 4. Other metabolites found were: the lactam of mesoridazine (rat), the lactam of mesoridazine ring sulphoxide (rat and human), mesoridazine N-oxide (human) and sulforidazine N-oxide (dog and human). 5. Mesoridazine and six of its metabolites present in urines of human, rat and dog were quantified by a h.p.l.c.-u.v. method. The mean total excretion of measured analytes in human, rat and dog were 6.3, 2.6 and 29.1%, respectively. The excretion of the lactam of sulforidazine ring sulphoxide was greater in human (0.4%) and rat (0.2%) than dog (0.02%). Moreover, the urinary excretion of the lactam of mesoridazine ring sulphoxide in human and rat constituted 0.4% and 0.2%, respectively. Of the three lactams found in rat the lactam of mesoridazine was present in the least amount (0.05%). 6. Interspecies comparison of the lactam metabolites indicated that both qualitatively and quantitatively human more closely resembled rat than dog. On the other hand, N-oxide metabolites were detected in human and dog but not in rat.

Molecular characterization of alpha 2-adrenergic receptors regulating intestinal electrolyte transport

Norepinephrine (NE) is an important neuromodulator of active Na+ and Cl- transport by the small intestine; however, the cellular targets and the adrenergic receptor (AR) subtype mediating its effects on ion transport have not been clearly defined. NE inhibited short-circuit current in submucosal-mucosal sheets of porcine distal jejunum under basal conditions and after electrical transmural stimulation of intrinsic neurons. A membrane fraction (P2) prepared from the submucosa of porcine jejunum was enriched in specific [3H]saxitoxin binding sites, relative to other submucosal fractions. This fraction contained homogeneous and high affinity sites binding the alpha 2-AR antagonist [3H]yohimbine (Kd = 0.39 +/- 0.03 nM). A prazosin versus oxymetazoline Ki ratio of 218 was obtained for the submucosal AR binding site, suggesting that it represents a neuronal alpha 2A-AR. A cell membrane fraction prepared from the mucosa exhibited specific and saturable high affinity binding of the muscarinic cholinergic antagonist [3H] quinuclidinyl benzilate (Kd = 77 +/- 9 pM) but displayed minimal specific binding of [3H]saxitoxin or [3H]yohimbine. A [32P]cDNA probe derived from the human alpha 2-C10 gene encoding the alpha 2A-AR hybridized to a 3.8-kilobase message that was prevalent in poly(A)+ RNA isolated from the jejuno-ileal submucosa and was also detected in porcine cerebral cortex and kidney; no message was detected in RNA isolated from the jejunal mucosa. These results suggest that NE modulates active ion transport in the small intestine through interactions with a submucosal alpha 2A-AR probably associated with enteric neurons.

The metabolism of piperidine-type phenothiazine antipsychotic agents. II. Sulforidazine in dog and human

1. The metabolism of sulforidazine was studied in female dogs and adult male humans after oral administration of 37.5 mg and 25.0 mg, respectively. 2. Metabolites in organic extracts of dog urine were separated by h.p.l.c. and individually collected prior to mass spectrometric analysis, while organic extracts of human urine were directly subjected to plasmaspray h.p.l.c.-mass spectrometric determination. In the case of phenolic metabolites, the urinary extracts from both species were derivatized with a silylating reagent (with or without prior enzymic hydrolysis) and subsequently analysed by h.p.l.c.-mass spectrometry. The structures of metabolites with the exception of phenols were confirmed by comparison of their mass spectra and chromatographic behaviours with those of authentic standards. 3. The compounds identified in urine of both species were sulforidazine, two diastereomers of sulforidazine ring sulphoxide, the lactam of sulforidazine ring sulphoxide and a phenolic derivative of sulforidazine, whereas sulforidazine N-oxide and the lactam of sulforidazine were identified only in human urine. Moreover the phenolic metabolite was present in human urine in both unconjugated and conjugated forms, whereas dog urine had only the conjugated form. 4. Sulforidazine and some of its major metabolites were quantified by an h.p.l.c. method. The mean urinary excretions (0-48 h) of sulforidazine were similar in human (n = 3) and dog (n = 3) (5.9 +/- 0.7% and 7.2 +/- 1.9%), as were the excretions of sulforidazine ring sulphoxide (13.2 +/- 4.6% and 13.3 +/- 4.4%), while the lactam of sulforidazine ring sulphoxide was a major metabolite only in human (7.5 +/- 2.8% and < 0.1%). The lactam of sulforidazine was a minor metabolite in human. 5. The metabolites observed in human urine were similar to those previously reported in rat, except that sulforidazine N-oxide was found only in human, whereas the two diastereomers of N-desmethylsulforidazine ring sulphoxide were observed only in rat. These data suggest that rat may be a more suitable animal than dog for further study of the metabolism of the piperidine ring of sulforidazine.

[A new method of enveloping volatile oils in Chinese medicinal herbs with beta-cyclodextrin]

A comparison has been made of the enveloping rate of volatile oil by three different methods with beta-cyclodextrin. The result indicates that the saturated water solution enveloping method is very close to the gas-liquid enveloping method, P greater than 0.05, but the liquid-liquid enveloping method is apparently higher than the saturated water solution enveloping method, P less than 0.01.

Stimulation of thymidine kinase activity in baculovirus infected cells is not due to a virus-coded enzyme

A polyhedrin-positive recombinant autographa californica nuclear polyhedrosis virus (AcNPV) carrying a herpes simplex virus thymidine kinase gene under the control of the SynXIV promoter, a fusion of synthetic and linker-modified polyhedrin promoters, has been constructed. When this recombinant baculovirus was used to infect a variant of Spodoptera frugiperda cells deficient in thymidine kinase (TK-), a high level of TK activity was detected. These results, in conjunction with the demonstration that AcNPV could replicate in TK- S. frugiperda cells and no TK activity was found throughout infection, imply that the wild type virus-stimulated TK activity observed in S. frugiperda (TK+) cells is not contributed by a virus-coded enzyme.

Role of aorto-angioplasty in hypertension caused by Takayasu's arteritis

Sixteen patients with Takayasu's arteritis and a long-stenotic segment of the descending thoracic aorta and/or proximal and middle portion of the abdominal aorta, with or without renal artery stenosis, were treated by percutaneous transluminal aorto-angioplasty (PTAA). These patients might be subdivided into three groups: A. with normal renal artery, B. with severe renal artery stenosis or occlusion without treatment or with failure of dilatation, and C. with renal artery stenosis but relieved by percutaneous transluminal renal angioplasty (PTRA). It was found that the hypertension may be caused by the suprarenal aortic stenosis itself. PTAA has an excellent effect to normalize the blood pressure in Group A. The elevated blood pressure may also be decreased in various extent in the patient with severe renal artery stenosis after PTAA, but not to normal. An additional PTRA or other renal vesel reconstruction procedure is necessary in this group. No recurrence of the aorta stenosis was found by non-invasive examinations or aortography during the long-term follow-up. PTAA may be considered as the first choice for the aortic stenosis caused by Takayasu's arteritis.

Multiple organ failure (MOF) after intestinal operations--a clinical and statistical study of the past 5 years

Multiple Organ Failure that occurred in 35 cases out of a total of 1498 cases after intestinal surgery were studied by an analysis of the clinical and statistical data from the past 5 years (1984-1988). 1. The incidence of MOF after intestinal surgery was 2.3%. 2. Twenty-eight of MOF resulted from severe infections. 3. The incidence of infection was highest after esophageal operations. 4. Hepatic failure was the most common type of primary organ failure and renal failure was the second most common. 5. The prognosis for MOF was very poor with a survival rate of 8.7%.

Effects of mobile phase composition on the reversed-phase separation of dipeptides and tripeptides with cyclodextrin-bonded-phase columns

The effects of mobile phase composition on the reversed-phase separation of several dipeptides and tripeptides with a gamma-cyclodextrin-bonded-phase column have been studied. The addition of organic modifier (i.e. methanol) into the aqueous buffer (pH 4.65) mobile phase causes a minimum capacity factor value to be observed for each peptide. This is interpreted to result from two retention mechanisms involved in the separation. The adsorption process causes the retention time to decrease as the water content in the mobile phase is increased. The inclusion process acts in the opposite fashion. The presence of Cu(II) salt in the mobile phase allows further modifications of separation selectivity. This is because the peptide conformation changes upon Cu(II) complexation which in turn alter the hydrophobicity and/or inclusion stability of the peptide. The effects of mobile phase pH (3.6-5.6) and ionic strength (0.001-0.06) were not significant in the present application. Studies with a beta-cyclodextrin column show similar results.

[Significance of umbilical and paraumbilical veins as collaterals in portal hypertension]

Twenty-one postmortem specimens of the liver (18 normal livers, 3 liver metastases) with attached ligamentum teres were investigated using silicone rubber injection technique. In all cases, the paraumbilical veins were demonstrated. They were usually divided into 2 groups, one on the right and the other on the left side of the ligamentum teres, and they terminated in a variable manner into small peripheral portal vein branches in the liver parenchyma. A patent proximal segment of the umbilical vein was found in 7 of the 21 cases. Connections between the umbilical vein and paraumbilical veins were supposed to represent one of the collateral channels in portal hypertension.