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Genetic and environmental aspects play an important role in the development of colorectal cancer. However, the common molecular alteration in both hereditary and sporadic colon cancer is localized in the APC gene. the APC gene maps in the long arm of chromosome 5 and was discovered in patients with familial adenomatous polyposis (FAP). The search for the APC gene led to the identification of restriction fragment length polymorphisms (RFLPs) in FAP patients. Using these RFLPs in relatives of FAP patients it is possible to make the presymptomatic and prenatal diagnosis. The FAP syndrome is an interesting model of carcinogenesis in vivo. Thus the different stages involved in the FAP syndrome which include hyperproliferative epithelium, adenoma, adenocarcinoma and metastases, have allowed the analysis of molecular alterations in oncogenes and tumor suppressor genes. The APC gene alteration if not inherited, occurs as the earliest molecular alteration in the development of colorectal cancer whereas structural alterations of the genes myc, ras, p53, MCC and DCC are considered to be late events. All these investigations have lead to 1) a better understanding of the ethiology of cancer and 2) early diagnosis of colorectal cancer in both the hereditary and sporadic forms of the disease.

We examined the effects of thrombin on tissue-type plasminogen activator (t-PA) release and t-PA mRNA levels in cultured human fetal lung fibroblast cells, IMR-90. The secretion of t-PA was increased by thrombin in a dose- and time-dependent manner, but it was not affected by inactivated thrombin with diisopropylfluorophosphate (DFP). Both antithrombin III (ATIII) and heparin cofactor II (HCII), plasma inhibitors to thrombin, inhibited thrombin-induced t-PA release. The thrombin-induced t-PA secretion was preceded by an increase of the steady state level of t-PA-specific mRNA in the cells, suggesting that thrombin activates t-PA gene expression. The t-PA mRNA expression induced by thrombin was completely blocked by pretreatment of the cells with an inhibitor of translation, cycloheximide (CHX). These results suggest that the effect of thrombin on t-PA expression is mediated through its proteolytic activity and the biosynthesis of transcription factor(s).

Analysis of 5180 liver transplant cases from 37 liver transplant centers in the United States (1982-1991) shows an overall one-year survival rate of 79.4 +/- 0.6% and a five-year survival rate of 69.2 +/- 0.9%. There was marked improvement in the one-year survival rate after liver transplantation from 36.0 +/- 9.6% in 1982 to 85.0 +/- 1.8% in 1991. One-year survival rates after liver transplantation for postnecrotic cirrhosis, primary biliary cirrhosis, alcoholic cirrhosis, primary sclerosing cholangitis, alpha-1-antitrypsin deficiency, and Wilson's disease ranged from 78.4 +/- 1.0% to 84.2 +/- 1.5% and five-year survival rates from 68.6 +/- 3.8% to 79.2 +/- 5.3%. Survival rates after liver transplantation for hemochromatosis were poor--a one-year survival rate of 53.8 +/- 6.8% and a five year survival rate of 43.1 +/- 11%. One- and five-year survival rates for the 0-13 years age group were 74.6 +/- 2.8% and 66.7 +/- 3.4%; for the 14-37 years age group, 83.3 +/- 1.2% and 73.8 +/- 1.8%; for the 38-54 years age group, 79.6 +/- 0.8% and 69.7 +/- 1.3%; for the 55-63 years age group, 76.0 +/- 1.4% and 63.0 +/- 3.1%; and for the 64-77 years age group, 76.5 +/- 3.0% and 65.4 +/- 4.6%.

Antithrombin (ATIII) is believed to be one of the body's most powerful natural anticoagulants, so individuals with a deficiency of this protein exhibit a marked propensity to venous thrombosis. This article will focus on the pathophysiology of this disorder, including clinical presentation, diagnosis, and treatment.

In contrast to the numerous studies of men, very few studies have been concerned with sex hormone disturbances in women with chronic alcoholic and non-alcoholic liver diseases. The aim of the study was, to evaluate the effect of ethanol and liver dysfunction on menstrual cycle, serum sex hormone concentrations and hepatic oestrogen receptors in women. In premenopausal female alcoholics ethanol consumption increase the frequency of menstrual disturbances, abortions, and miscarriages, while infertility is not frequent. Acute ethanol intoxication has only minor effects on pituitary-gonadal hormones in premenopausal women, while chronic ethanol abuse lead to reduced concentrations of sulphated steroids, and these changes may be seen before severe liver dysfunction has appeared. In women liver dysfunction lead to earlier occurrence of menopause in comparison with normal controls, while information is insufficient or lacking regarding the influence upon fertility, pregnancy outcome and sexual behavior in women. In postmenopausal women with alcoholic and non-alcoholic liver disease, the main disturbances of sex hormone metabolism consist of elevated oestrone and sex hormone binding globulin (SHBG) concentrations, while serum concentrations of steroid sulphates and 5 alpha-dihydrotestosterone (DHT) are reduced, and the degree of liver dysfunction is a major determinant for the observed disturbances. The presence of high affinity, low capacity, specific oestrogen receptors (ER) in the liver is confirmed using a ligand binding assay (DCC), specificity analyses, and sucrose gradient centrifugation. Furthermore, the sensitivity of an enzyme immunoassay has been improved enabling the quantitative measurement of hepatic ER in 102 small liver biopsies from patients with alcoholic and non-alcoholic liver diseases. The method is suitable for quantitative assessment and ER in small tissue samples, and can be applied to other tissues than the liver. Patients with chronic liver diseases have significantly lower hepatic ER concentrations, and this reduction is determined by the degree of liver dysfunction, while the degree of alcoholic hepatitis or active ethanol consumption are less important factors. The importance of this observation for hepatic physiology and pathophysiology remains to be determined.

The tumor suppressor genes p53, Rb, and DCC were studied in five human oral cancer cell lines (FaDu, SCC-4, HEp-2, 1483, and OEC-M1) and in primary normal human oral keratinocytes (NHOK). All tested cancer lines had similar amount of p53 messages to normal cells, but the cancer lines FaDu and SCC-4 contained significantly higher p53 protein levels than did the normal counterpart. Sequencing p53 cDNA for these cancer cells showed point mutations: In the FaDu cell line, a mutation of CGG to CTG occurred at codon 248; and in the SCC-4 cell line, a mutation of CCC to TCC occurred at codon 151. The HEp-2 and 1483 cancer lines translated very low levels of p53 protein compared to the normal counterpart. Sequencing of p53 cDNA for HEp-2 and 1483 lines showed no mutations. Southern and Northern analyses revealed that these cell lines harbored HPV-18 DNA and expressed the viral E6/E7 protein. The OEC-M1 line showed different restriction fragment length polymorphism for the p53 gene compared with other cells, and did not express p53. All oral cancer cell lines except the OEC-M1 cells expressed both phosphorylated and hypophosphorylated Rb proteins. Further, the OEC-M1 line expressed smaller sized hypophosphorylated Rb proteins compared with normal cells. Unlike the other cancer lines, the HEp-2 and OEC-M1 lines also did not contain DCC mRNAs. These data indicate that "high risk" HPV infections and mutations of p53, Rb, and DCC genes are frequently found in oral cancer cells and may be associated with oral cancer.

IT15 is a novel gene, localized to chromosome 4, and encoding a protein named Huntingtin. A polymorphic CAG repeat in the proposed open reading frame of IT15 has been characterized, and an elongation of this repeat has been correlated to Huntington's Disease. We have investigated the CAG repeat in the Huntingtin gene in 71 unrelated Danish patients with Huntington's Disease, and found repeat lengths of 39 to 70 repeat units in contrast to 9 to 30 CAG's on normal chromosomes. Comparison of repeat length and age at onset of disease symptoms in 52 individuals indicates an inverse correlation between the age at onset and the number of CAG repeat units.

Recombinant human soluble thrombomodulin (rhs-TM), having no transmembrane domain or chondroitin sulfate, was expressed in Chinese hamster ovary cells. Interactions between rhs-TM, thrombin (Th), protein C (PC) and antithrombin III (ATIII) were studied. Equilibrium between rhs-TM and Th had no detectable time lag in clotting inhibition (Kd = 2.6 nM) or PC activation (Kd = 22 nM), while ATIII inhibited Th at a bimolecular rate constant = 5,200 M-1s-1 (Kd < 0.2 nM). A mixture of ATIII, Th and rhs-TM showed that ATIII reacted with Th slower than rhs-TM, whose presence did not affect the reaction between ATIII and Th. In a mixture of rhs-TM, ATIII and PC, the repeated addition of Th caused the repeated activation of PC; which was consistent with the simulation based on the assumption that rhs-TM is recycled as a Th cofactor. From these results, we concluded that upon inhibition of the rhs-TM-Th complex by ATIII, rhs-TM is released to recombine with free Th and begins to activate PC, while the Th-ATIII complex does not affect rhs-TM-Th equilibrium.

The aim of this study was to investigate the mechanism by which the anticoagulant activity of dermatan sulfate (DS) is increased by low molecular weight heparin (LMWH). In platelet poor plasma, LMWH enhances the effect of DS on thrombin (IIa) inhibition as determined by thrombin clotting times and with a chromogenic substrate assay. Analysis of the results of the chromogenic assays using either the algebraic fractional or the graphic isobole method suggests that LMWH has an additive effect on the anti-IIa activity of DS. This additive effect was lost when the experiments were repeated in plasma immunodepleted of antithrombin III (ATIII), indicating that the anti-IIa activity of LMWH is ATIII-dependent. To further explore the mechanism of the interaction between LMWH and DS, 125I-labeled IIa was added to plasma in the presence or absence of DS and/or LMWH and the formation of IIa-inhibitor complexes was assessed using SDS-PAGE followed by autoradiography. DS addition selectively increases the formation of heparin cofactor II (HCII)-IIa complexes, whereas LMWH enhances ATIII-IIa complex generation. Compared to plasma containing DS alone, the formation of ATIII-IIa complexes also is increased when the combination of DS and LMWH is added. These findings suggest that the additive effect of LMWH on the anti-IIa activity of DS reflects their different modes of IIa inhibition; DS potentiates IIa inhibition by HCII, while LMWH catalyses ATIII-dependent IIa inactivation. The potential clinical significance of these findings requires further investigation.

The anticoagulant activities of Tissue Factor Pathway Inhibitor (TFPI), heparin and hirudin were compared in intrinsic (APTT) and extrinsic (PT) activated clotting assays. In contrast to the thrombin inhibitor hirudin, heparin was 10 fold more potent in the APTT assay than in the PT assay, indicating that inhibition of intrinsic activation is important for the anticoagulant activity of heparin as measured in an APTT assay. TFPI was most potent in the PT assay and the effect of TFPI was most pronounced in the presence of other anticoagulants (heparin and hirudin). The activities of the two natural anticoagulants antithrombin III (ATIII) and TFPI were compared in a PT assay with very dilute tissue factor. In this assay system TFPI in normal plasma affected the clotting time more than ATIII in the plasma. However, when heparin was added ATIII was the major anticoagulant, but profound prolongation of the clotting time was only seen when TFPI was also added. In an ATIII deficient plasma heparin did not augment the effect of TFPI, showing that the increased effect of TFPI in the presence of heparin is dependent on the anticoagulant activity of ATIII/heparin. The effect of TFPI at prolonged clotting times was also illustrated by the significant effect of blocking TFPI in the plasma from warfarin-treated patients. Thus TFPI is a major anticoagulant in normal plasma and the effect of TFPI is especially seen at prolonged clotting times.

Estrogen and progesterone receptors (ER and PR) in 18 cases of ovarian endometriosis and 13 cases of adenomyosis were determined with dextran coated charcoal (DCC) method. The levels of ER and PR in those specimens were lower than those of normal endometrium. Among the 18 cases of ovarian endometriosis, 6 (33.4%) were negative for PR, which accounted for the unsatisfactory results of progesterone treatment for some endometriosis. In the 13 cases of adenomyosis there were 10 (76.9%) showing positive PR. It is suggested that the hormone therapy may be useful to treat those young patients with adenomyosis instead of surgery. The correlation of the ER and PR levels, the treatment and prognosis in endometriosis and adenomyosis are worth further studying.

Adhesion molecules are thought to play a vital role in the induction and maintenance of tissue differentiation and their loss or down-regulation has been implicated in the neoplastic process. Recent studies have shown that the morphoregulatory activities are a consequence of interactive processes between several cell adhesion molecules rather than the function of a single molecule. Therefore, we have investigated a panel of adhesion molecules including members of the integrin, cadherin and immunoglobin superfamily in colorectal cancer. Twenty-eight consecutive colorectal adenocarcinomas were stained using an avidin-biotin indirect immunoperoxidase technique. Our results showed a consistent loss of the alpha 2 and beta 1 integrin subunits (21/28 = 75% and 22/28 = 78.6% respectively) and a decrease in expression of E-cadherin in 5/5 poorly differentiated adenocarcinomas. Carcinoembryonic antigen expression was preserved but with basolateral accentuation seen in tumours. There was no statistical correlation with Dukes' stage. These results provide further evidence that in colorectal cancer there is a widespread deregulated expression of cell-cell and cell-matrix adhesion molecules. Changes in the expression and function of adhesion molecules which regulate growth and differentiation may play a role in the behaviour of colorectal cancer.

Most Borrelia burgdorferi strains have two major surface proteins, OspA and OspB. In the present study, we selected from a clonal population of infectious B. burgdorferi an OspB escape mutant, identified the genetic basis for this phenotype, and evaluated its functional activities. Selection with the anti-OspB antibody H614 was performed in vitro in medium and extended in vivo in scid mice. Mutants with a truncated OspB protein were selected at a frequency of 1 x 10(-5) to 3 x 10(-5). After no major rearrangements in DNA were detected, sequence analysis of the mutant's ospAB locus revealed a single base change in the consensus ribosomal binding sequence for ospB and a single nucleotide deletion in the ospB gene itself. The effect of these mutations was reduced expression of a truncated OspB protein. When functional abilities of the wild type and mutant were compared, the mutant had a threefold-lower capacity to penetrate a human endothelium umbilical vein cell monolayer. Infectivity of wild-type and mutant cells for scid mice was evaluated by culturing different organs, and the median infectious dose was calculated. The inoculum of mutant cells for infecting the mice was 30- to 300-fold higher than that of wild-type cells. This study shows that reduced size and expression of OspB are associated with lowered virulence of B. burgdorferi. Selection of mutants that to some degree remain infectious is one approach to defining the role of different surface proteins in the pathogenesis of Lyme disease.

The classical plasma protein antithrombin III (ATIII), an inhibitor of the blood coagulation cascade, is a member of the serpins that are gaining import in the nervous system. In this study, we examined the presence of ATIII in the pathological lesions of Alzheimer's disease (AD). Antibodies to ATIII consistently detected approximately 58-kd protein(s) on immunoblots of cerebral cortex and brain microvessels. Immunocytochemical studies showed ATIII reactivity within amyloid deposits, neurites associated with plaques, and neurofibrillary tangles in neocortex and hippocampus of virtually all the AD cases examined. In some cases, astrocytes were also stained, suggesting ATIII in these cells. ATIII immunoreactivity in neurofibrillary tangles was further defined by electron microscopy, which showed it to be associated with paired helical filaments. Using the polymerase chain reaction technique to amplify ATIII complementary DNA, we found low levels of messenger RNA expression, relative to liver, in control human brain samples, and these were increased in AD samples, particularly in the white matter. Our results suggest the increased presence of ATIII commensurate with astrogliosis and association with the neurofibrillary pathology of AD. We conclude that in concert with other amyloid-associated serine protease inhibitors, ATIII may play a role in the pathogenesis of cerebral amyloidosis.

<h4>Background</h4>Septic shock is frequently complicated by a syndrome of disseminated intravascular coagulation (DIC). Numerous uncontrolled clinical studies have reported that antithrombin III (ATIII) substitution might prevent DIC and death in septic shock.<h4>Methods</h4>We conducted a randomized double-blind placebo-controlled trial in patients with a documented septic shock and DIC. The patients received either a placebo or ATIII (90 to 120 IU/kg in loading dose, then 90 to 120 IU/kg/d during 4 days). Administration of fresh frozen plasma, platelets, and fibrinogen concentrates was restricted to patients with hemorrhages and severe decreases in prothrombin time, platelet count, and fibrinogen levels.<h4>Results</h4>Thirty-five patients entered the study (18 placebo, 17 ATIII). Both groups were well balanced for all demographic, hemodynamic, and biologic data. Three patients were excluded before the treatment allocation code was broken. In the ATIII group, ATIII levels were rapidly corrected and remained over normal levels until day 10; sequential protein C and protein S levels were not modified. The duration of DIC was significantly reduced: in the ATIII group, 64 percent of patients were cured of DIC at day 2, and 71 percent were cured at the end of treatment vs in the placebo group, 11 percent (p < 0.01) and 33 percent (p < 0.05), respectively. In the 32 included patients, the mortality in ICU was reduced by 44 percent in the ATIII group (p = 0.22, NS). Care loads and transfusion requirements were not different. No side effect was observed.<h4>Conclusions</h4>Mortality was reduced by 44 percent in this trial, but the difference did not reach the statistical significance. Circulating protein C and protein S levels were not modified by ATIII supplementation. High doses of ATIII concentrates significantly improved sepsis-induced DIC during septic shock. The trend toward improved survival suggests further randomized studies.

The macrocyclic peptide cyclotheonamide A (CtA), isolated from the marine sponge Theonella sp., represents an unusual class of serine protease inhibitor. A complex of this inhibitor with human alpha-thrombin, a protease central to the bioregulation of thrombosis and hemostasis, was studied by x-ray crystallography. This work (2.3-A resolution) confirms the structure of CtA and reveals intimate details about its molecular recognition within the enzyme active site. Interactions due to the "Pro-Arg motif" (Arg occupancy of the S1 specificity pocket; formation of a hydrogen-bonded two-strand antiparallel beta-sheet with Ser214-Gly216) and the alpha-keto amide group of CtA are primarily responsible for binding to thrombin, with the alpha-keto amide serving as a transition-state analogue. A special interaction with the "insertion loop" of thrombin (Tyr60A-Thr60I) is manifested through engagement of the hydroxyphenyl group of CtA with Trp60D as part of an "aromatic stacking chain." Biochemical inhibition data (Ki values at 37 degrees C) were obtained for CtA with thrombin and a diverse collection of serine proteases. Thus, CtA is just a moderate inhibitor of human alpha-thrombin (Ki = 0.18 microM) but a potent inhibitor of trypsin (Ki = 0.023 microM) and streptokinase (Ki = 0.035 microM). The relative lack of potency of CtA as a thrombin inhibitor is discussed with respect to certain structural features of the enzyme complex. We also report the total synthesis of CtA, by a convergent [2 + 3] fragment-condensation approach, to serve the preparation of cyclotheonamide analogues for structure-function studies.

To evaluate the molecular events in the genome that are associated with myelodysplastic syndromes (MDS) and the development of leukemia, we investigated the expression of the deleted in colorectal carcinoma (DCC) gene by the reverse transcriptase-polymerase chain reaction (RTPCR) method in 24 MDS cases and in 7 overt leukemia cases that progressed from MDS. Expression of the DCC gene was absent or extremely reduced in 2 of the 24 MDS cases, and those 2 cases developed overt leukemia within 6 months. Moreover, in 5 of the 7 cases of overt leukemia that developed from MDS, expression of the DCC gene was absent or extremely reduced. These findings suggest that inactivation of the DCC gene may be the late event that triggers the progression of MDS to leukemia.

The cell surface glycoprotein MUC18, a member of the immunoglobulin superfamily and homologous to several cell adhesion molecules, is associated with tumor progression and the development of metastasis in human malignant melanoma. Immunohistochemical and Northern blot analysis revealed that expression of the antigen is restricted to advanced primary and metastatic melanomas and to cell lines of the neuroectodermal lineage. The genomic sequence encoding the cell surface antigen spans approximately 14 kb and consists of 16 exons. The organization of the gene, which is related to that of the neural cell adhesion molecule N-CAM, shows a structure where each immunoglobulin-related domain is encoded by more than one exon. Sequencing of the putative MUC18 promoter region revealed a G + C-rich promoter lacking conventional TATA and CAAT boxes. Several motifs for binding of transcription factor Sp1 are present in the regulatory region, and only a single transcription start site within a presumed initiator sequence was identified. Sequence elements which might confer melanocyte-specific expression were not detected. Instead, recognition sequences for the transcription factors CREB, AP-2, and c-Myb, as well as CArG-box motifs, were observed. These elements may contribute to the differential regulation of the MUC18 gene in normal and malignant tissues and suggest a role for this putative adhesion molecule in neural crest cells during embryonic development.

Cells of a patient with Turcot's syndrome and of her parents were evaluated for the presence of molecular alterations in the p53 and the Ki-ras gene. Deletions on chromosome 17p, overexpression and point mutations of the p53 gene as well as mutations of the Ki-ras gene were detected in primary and metastatic tumour but not in the germline of the patient nor in her parents.

Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by motor disturbance, cognitive loss, and psychiatric manifestations. It is inherited in an autosomal dominant fashion. The genetic defect causing HD was assigned to chromosome 4 in 1983 using polymorphic DNA markers in humans. Thereafter, a location cloning approach was pursued to isolate and characterize the HD gene. Recently, the Huntington's disease collaborative research group has isolated a new gene, IT 15, in 4p 16.3. IT 15 contains a polymorphic trinucleotide repeat that is expanded and unstable on HD chromosomes. A (CAG)n repeat longer than the normal range was observed on HD chromosomes from disease families. The (CAG)n repeat appears to be located within the coding sequence of a predicted 348 kd protein that is unrelated to any known gene.