Gene Literature Dashboard

<h4>Objective</h4>To explore the role of hypercoagulation in the metastasis of carcinoma.<h4>Methods</h4>The effect of Tetramethylpyrazine (TTMP) on platelet functions among the 25 advanced cases of lung carcinoma, and 26 matched control subjects were investigated in the study. Their ages varied from 31-86 years (mean 58.2) in lung carcinoma group (13 male, 12 female) and 36 to 61 (mean 52.9) in the control group (16 male, 10 female). The pathologic types were as follows: 7 cases of squamous cell cancer, 12 adenocarcinoma, 2 small cell carcinoma and 4 undistinguished type. The TNM stage revealed 14 cases in stage IIIa, 3 in stage IIIb and 8 in stage IV. The site of metastasis included mediastinal lymph node, pleura, supraclavicular lymph node, brain, spine, costa, skin and pericardium. The levels of plasma TXB2, 6-keto-PGF1 alpha, VIII:C, vWF, AT-III:a, AT-III:Ag, Fg and blood PAdT, PAgT were measured before and after the intravenous infusion of 80 mg TTMP in patients with lung carcinoma.<h4>Results</h4>The levels of TXB2, 6-keto-PGF1 alpha, VIII:C, vWF and Fg in lung carcinoma group were significantly elevated, while the levels of PAdT was greatly decreased, compared with the control group, no significant differences in levels of PAgT, AT-III:a and AT-III:Ag were found between the two groups. After the infusion of TTMP the levels of PAdT, PagT, VIII:C, dWF and Fg were decreased significantly, while TXB2, 6-keto-PGF1 alpha, AT-III:a and AT-III:Ag remained unchanged.<h4>Conclusions</h4>TTMP inhibits the adhesion and aggregatory functions of blood platelet and the activity of coagulation factors. It might be one of the mechanisms of TTMP's antimetastasis of lung carcinoma.

<h4>Aim</h4>To assess the effects of the deleted in colorectal cancer (DCC) gene changes on the development and progression of gastric cancer.<h4>Methods</h4>The loss of heterozygosity (LOH) and mRNA expression DCC gastric cancer using a PCR-based detection method.<h4>Results</h4>LOH was found in 35.3% (18/51) of the specimens, and the LOH was more frequently detected in tumors from patients with stage III or IV cancer (50.5%) than those in stages I or II (14.3%) (P < 0.05). The occurrence of LOH was not found to correlate with the histological type, tumor size, invasion depth and lymph node metastasis of gastric cancer. The mRNA expression of the DCC gene was studied in 26 of the 51 cases, of which LOE was found in 30.8% (8/26). LOE was not significantly correlated to LOH or other clinicopathological parameters.<h4>Conclusion</h4>LOH and LOE of DCC gene are frequently encountered in gastric cancer, and the LOH of DCC gene is a late event associated with progression of gastric cancer.

The deleted in colorectal cancer (DCC) gene encodes a neural cell adhesion family molecule that was originally identified as a candidate tumor suppressor target of 18q allelic loss in colorectal cancer. However, the importance of the DCC protein has been most clearly demonstrated in neural development. Mutational and subsequent biochemical studies in C. elegans, Drosophila and vertebrates have shown that DCC functions in the guided migration of cells and cell processes in response to stimuli from netrins, a family of secreted laminin-like proteins. It appears that DCC may act in this signal transduction pathway as a netrin receptor or a component of the receptor complex, though a definitive receptor:ligand relationship has not yet been demonstrated. It is also clear that DCC can affect migrations in a netrin-independent manner, implying the existence of other DCC ligands. Though the loss of DCCexpression appears to be a later event in several malignancies and is associated with disease dissemination, it has not been adequately demonstrated that DCC is the tumor suppressor gene targeted by 18q allelic loss. However, DCC expression does have potential clinical utility as it stratifies an important group of colorectal cancer patients into good and poor prognosis subgroups.

Thromboembolic disease and progression to disseminated intravascular coagulation (DIC) are potential life-threatening complications for dogs with nephrotic syndrome. Platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), plasma concentration of fibrinogen degradation products (FDPs), antithrombin III (ATIII), protein C, and plasminogen were used to identify hemostatic abnormalities in a dog with nephrotic syndrome. Pulmonary thromboembolic disease was diagnosed by thoracic radiography, arterial blood gas analysis, and pulmonary scintigraphy. Prompt recognition and treatment of hemostatic complications is necessary in dogs with nephrotic syndrome.

Mel-CAM (MUC18 or CD146) is a cell adhesion molecule sharing sequence homology with members of the immunoglobulin gene superfamily. Mel-CAM was originally described as a marker associated with invasion and metastasis in melanoma. We determined here the distribution and biological significance of Mel-CAM in normal, benign proliferative, and neoplastic breast ductal epithelium. Using a Mel-CAM-specific monoclonal antibody, we, immunohistochemically demonstrate Mel-CAM expression in 14 of 14 (100%) normal breast epithelia and benign proliferative ductal epithelial lesions, whereas Mel-CAM expression can only be focally detected in 12 of 72 (17%) breast carcinomas. Solid-phase cell adhesion assay revealed that breast carcinoma cells in culture express the ligand for Mel-CAM. Transfection of Mel-CAM cDNA into breast carcinoma cells induces a more cohesive cell growth pattern and establishes smaller tumors in immunocompromised mice than mock transfectants. In conclusion, Mel-CAM is distributed throughout normal and benign proliferative mammary ductal epithelium, but it is frequently lost in carcinomas; it functions as a heterophilic cell-cell adhesion molecule in breast epithelium, and loss of Mel-CAM expression in breast carcinoma may be an important step for tumor progression.

<h4>Background</h4>Inborn errors of bile acid synthesis are newly recognized disorders that may cause the phenotypic appearance of neonatal hepatitis or neonatal cholestasis.<h4>Methods</h4>This is a clinicopathologic study of two sets of siblings with cholestatic neonatal liver failure.<h4>Results</h4>In 3 of the infants, diagnostic evaluation, including analysis of urinary bile salts, revealed a predominance of 7 alpha-hydroxy-3-oxo-4-cholenoic and 7 alpha, 12 alpha-dihydroxy-3-oxo-4-cholenoic acids, a pattern consistent with delta 4-3-oxosteroid 5 beta-reductase deficiency, which could be primary or secondary. The fourth infant died before such testing could be carried out. In addition, all 4 infants had histologically disseminated hemochromatosis and met diagnostic criteria for neonatal hemochromatosis. In the 3 infants studied, histologic examination of the liver disclosed giant cell hepatitis with extensive loss of hepatic parenchyma and rapid progression to cirrhosis. Early treatment with ursodeoxycholic acid and cholic acid, previously reported as effective therapy, was given to 2 siblings; it failed to reverse or halt the liver damage, and both infants died. One infant, with the original diagnosis of neonatal hemochromatosis, was treated with a variety of antioxidants and chelation therapy, as recently reported. No improvement was demonstrated, and he went on to liver transplantation.<h4>Conclusions</h4>The presentation of delta 4-3-oxosteroid 5 beta-reductase deficiency as neonatal hemochromatosis may represent a distinct subset of this disorder with an accelerated course, no response to therapy and poor prognosis.

Loss of heterozygosity (LOH) on chromosome 18q21 is found frequently in various human cancers. Three candidate tumor suppressor genes, DCC (deleted in colorectal carcinomas), DPC4 (deleted in pancreatic carcinomas, locus 4), and MADR2/JV18-1 (MAD-related gene 2), have been cloned and identified from this chromosome region. We have reported recently that LOH on chromosome 18q is observed frequently in neuroblastoma. Alterations of DCC are involved in many human tumors. DPC4 and MADR2/JV18-1 are recently demonstrated to be altered in pancreatic and colorectal cancers, respectively. To confirm if inactivation of the DCC, DPC4, and MADR2/JV18-1 genes is involved in the pathogenesis of neuroblastoma and to clarify the mechanism of inactivation, we analyzed the expression of DCC, DPC4, and MADR2/JV18-1 in neuroblastoma cell lines and primary tumors by reverse transcription-PCR and investigated the mutations in the coding regions of these genes by PCR/reverse transcription-PCR single-strand conformation polymorphism. We found that 12 of 25 (48%) cell lines and 14 of 32 (44%) primary tumors, including 3 with 18q LOH, had absent or reduced expression of DCC mRNA. Expression was more likely to be reduced in advanced (67%) than in early stage neuroblastomas (24%) (P = 0.036), suggesting that inactivation of the DCC gene plays an important role in the progression of neuroblastoma. Altered expression of DPC4 was found in six (24%) cell lines and six (19%) tumors. MADR2/JV18-1 expression was reduced or absent only in four (16%) cell lines and three (9%) tumors. Mutations of the DCC genes were examined in 25 of 29 exons in neuroblastoma cell lines, and those exons in which mutations were found were further examined in primary tumors. We found missense mutations of AAC (Asn) to AGC (Ser) at DCC codon 176 in one cell line and ACC (Thr) to ATC (Ile) at codon 1105 in one cell line and tumor, respectively; polymorphisms of CGA (Arg) to GGA (Gly) at codon 201 and TTT (Phe) to TTG (Leu) at codon 951 in most of the cell lines and tumors; and a silent mutation of GAG (Glu) to GAA (Glu) at codon 118 in four cell lines and five primary tumors. We did not identify any mutations in the DPC4 and MADR2/JV18-1 genes in neuroblastoma. Our results suggested that mutations of the DCC gene may be involved in the pathogenesis of neuroblastomas but failed to account for the relatively high frequency of the altered expression, implying that other mechanisms are responsible for the inactivation of the DCC gene in neuroblastoma. Low frequency of reduced or absent mRNA expression and lack of mutations in DPC4 and MADR2/JV18-1 genes suggested a limited role for these two genes in neuroblastoma.

<h4>Objective</h4>To assess the importance of iron overload as a risk factor for porphyria cutanea tarda (PCT).<h4>Design</h4>Prospective study during a 4-month period.<h4>Setting</h4>Departments of emergency care, gastroenterology, and dermatology in a tertiary referral center.<h4>Patients</h4>Patients were deemed eligible for inclusion in the study if serum ferritin levels were greater than 500 micrograms/L (normal range: females, < 125 micrograms/L; males, < 325 micrograms/L).<h4>Main outcome measures</h4>Porphyrin excretion profiles were analyzed on all patients included in the study, where clinically relevant. A diagnosis of PCT was confirmed biochemically in all cases. The HLA typing was then performed on newly diagnosed cases of PCT.<h4>Results</h4>Of 4127 patients tested, 240 patients with an elevated serum ferritin level were identified, of whom 74 had an elevated serum ferritin level of more than 500 micrograms/L. Of the latter group, 17.5% had hemochromatosis and 6.7% had PCT. The incidence of PCT in the hemochromatosis group was 23%; HLA typing revealed the presence of at least 1 of the hemochromatosis markers.<h4>Conclusions</h4>A high serum ferritin level in the absence of evident cause should prompt investigation for both hemochromatosis and PCT. The HLA heterozygosity for hemochromatosis in some patients with PCT may be a cause of hepatic siderosis.

Synthesis and pharmacological properties of new potent direct activators of heterotrimeric G proteins are described. Compounds were synthesized from protected amino acids with alkylamines using coupling reagents (CDI, DCC, and EDC). Alkyl-substituted amino acid amides and their corresponding di- and triamines were subjected to structure-activity analysis. All compounds activated membrane-bound HL-60 GTPases in a pertussis toxin-sensitive fashion. This suggests a specific effect of compounds on the carboxy terminus of a defined subclass of heterotrimeric G proteins, i.e., members of the G alpha i subfamily. Elongation of the alkyl chain and increasing the number of amino groups enhanced the potency of compounds on HL-60 membrane-bound GTPase. N-(2,5-Diaminopentyl)dodecylamine (21) was selected to study its mode of action employing purified pertussis toxin-sensitive G proteins. It stimulated G alpha subunits by inducing the release of bound GDP. In contrast to receptors G beta gamma complexes were not required for 21-mediated activation of G alpha. Moderate isoform selectivity of its action was observed within a group of highly homologous members of the Gi subfamily with G alpha o1 being activated at lowest concentrations, whereas higher concentrations were necessary for the stimulation of G alpha i1 or transducin. We conclude that these compounds represent important tools for studying G protein-dependent cellular functions.

We have examined the reactivity of monoclonal antibodies (MAbs) specific for Lewis antigens (Le(x), Le(y), Le(a), and Le(b)) with Helicobacter pylori lipopolysaccharides (LPS) by immunoblot analysis and enzyme-linked immunosorbent assay (ELISA). Sixty-eight strains of H. pylori were isolated from patients with chronic gastritis, gastric and duodenal ulcers, and gastric cancer in Japan. The cells were treated with proteinase K, and the resulting fractions were used as a source of LPS for the immunoassays. In the immunoblot analysis, 28 isolates (41%) and 29 isolates (42%) reacted with anti-Le(x) and anti-Le(y) MAbs, respectively, while 4 isolates (6%) and 7 isolates (10%) reacted with anti-Le(a) and anti-Le(b) MAbs. On the other hand, in ELISA, the number of isolates that reacted with anti-Le(x) MAbs fell significantly to 21 isolates (30%) but the number of isolates that reacted with the other anti-Lewis antigen MAbs remained relatively unchanged. These data show that the immunoblotting technique is more sensitive than the ELISA technique for the detection of immunocomplexes of anti-Le(x) MAbs and components of H. pylori LPS. Furthermore, human serum was found to react with the synthetic Lewis antigens regardless of the status of the individual's H. pylori infection. This means that humans may naturally possess antibodies against Lewis antigens in the absence of H. pylori infection.

The cause of neurodegeneration in Huntington's disease (HD) is unknown. Patients with HD have an expanded NH2-terminal polyglutamine region in huntingtin. An NH2-terminal fragment of mutant huntingtin was localized to neuronal intranuclear inclusions (NIIs) and dystrophic neurites (DNs) in the HD cortex and striatum, which are affected in HD, and polyglutamine length influenced the extent of huntingtin accumulation in these structures. Ubiquitin was also found in NIIs and DNs, which suggests that abnormal huntingtin is targeted for proteolysis but is resistant to removal. The aggregation of mutant huntingtin may be part of the pathogenic mechanism in HD.

A novel variant of the chimerical MLL-AF10 mRNA transcript was detected in a pediatric patient with acute myeloid leukemia (AML) by a new asymmetric reverse-transcription polymerase chain reaction (ART-PCR) method. Sequence analysis of the fusion region on the amplified cDNA fragment showed an in-frame joining of exon e5 of the MLL gene and position 1931 of the cDNA sequence of the AF10 gene, giving rise to a new MLL-AF10 transcript. The presence of the new chimerical mRNA product in a sample from the patient was confirmed by classical RT-PCR.

<h4>Background</h4>Hepatocellular carcinoma (HCC) is one of the most common human tumors in Asia and Africa. The molecular genetic changes involving both protooncogenes and tumor suppressor genes are known to be involved in hepatocarcinogenesis, but the roles of the known tumor suppressor genes in hepatocarcinogenesis are not fully elucidated. In this study, the authors analyzed the loss of heterozygosity (LOH) of known tumor suppressor genes in HCC and evaluated the relationship between LOH of tumor suppressor genes and clinicopathologic features.<h4>Methods</h4>The authors assessed the LOH of the 10 known tumor suppressor genes (VHL, APC, EXT1, WT1, Rb1, p53, BRCA1, nm23, DPC4, and DCC) with microsatellite markers in 29 consecutively resected HCC specimens.<h4>Results</h4>The authors found frequent LOH of tumor suppressor genes in HCC. Twenty five of 29 cases (86%) had LOH of tumor suppressor genes and 17 cases (59%) had LOHs involving 2-4 tumor suppressor genes. Among the tumor suppressor genes, frequent LOH was noted in the p53 (66%), Rb1 (33%), EXT1 (33%), and APC (20%) genes. LOH of the p53 gene and multiple LOH of the tumor suppressor genes were more frequent in poorly differentiated HCCs (P = 0.02).<h4>Conclusions</h4>The LOH of tumor suppressor genes is frequent in HCCs and LOH of the p53 gene and accumulated LOHs are related to poorly differentiated HCC. Abnormalities of the p53 gene or the accumulated abnormalities of the tumor suppressor genes may play a role in the aggressive progression of HCC.

Congenital homocysteinuria is a rare inherited metabolic disorder with early onset atherosclerosis and arterial and venous trombosis. Moderate hyperhomocysteinemia is more frequently encountered and is recognized as an independent cardiovascular risk factor. Several case-control studies demonstrate an association between venous thromboembolism and moderate hyperhomocysteinemia. A patient with moderate hyperhomocysteinemia has a 2-3 relative risk of developing an episode of venous thromboembolism. The occurrence of mild hyperhomocysteinemia in heterozygotes for the mutation of Leiden factor V involves a 10-fold increase in the risk of venous thromboembolism. The biochemical mechanism by which homocysteine may promote thrombosis is not fully recognized. Homocysteine inhibits the expression of thrombomodulin, the thrombin cofactor responsible for protein C activation, and inhibits antithrombin-III binding. Treatment with folic acid reduces the plasma level of homocysteinemia, but no study has demonstrated its efficacy in reducing the incidence of venous thromboembolism or atherosclerosis. Hyperhomocysteinemia should be included in the screening of abnormalities of hemostasis and thrombosis in patients with idiopathic thromboembolism, and mild hyperhomocysteinemia may justify a trial of folic acid.

<h4>Background/aims</h4>The risk of cholangiocarcinoma in primary sclerosing cholangitis is widely recognized to be 8-30%, whereas the risk of acquiring hepatocellular carcinoma in primary sclerosing cholangitis is unknown. As in other chronic liver diseases, the presence of hepatocellular carcinoma in a patient with primary sclerosing cholangitis undergoing evaluation for orthotopic liver transplantation would clearly impact on the candidacy, diagnostic evaluation, and alternative treatment options. Thus, the aim of our study was to determine the prevalence of hepatocellular carcinoma in patients undergoing liver transplantation for primary sclerosing cholangitis.<h4>Methods</h4>The records of the 520 patients undergoing orthotopic liver transplantation at our institution between 1985 and May 1995 were reviewed. Of the 134 patients with primary sclerosing cholangitis, three (2%) had hepatocellular carcinoma. In the 386 patients without primary sclerosing cholangitis undergoing orthotopic liver transplantation, 22 (6%) had hepatocellular carcinoma.<h4>Results</h4>Neither the duration of primary sclerosing cholangitis (range 7-23 years) nor the presence of ulcerative colitis (two of three patients) distinguished those patients with primary sclerosing cholangitis plus hepatocellular carcinoma from those with primary sclerosing cholangitis alone. None of the three patients with primary sclerosing cholangitis plus hepatocellular carcinoma had evidence for hepatitis B or C, alpha-1-antitrypsin deficiency, or hemochromatosis. None of the tumors was of the fibrolamellar variety of hepatocellular carcinoma.<h4>Conclusions</h4>The prevalence of hepatocellular carcinoma in patients with primary sclerosing cholangitis undergoing orthotopic liver transplantation is 2%. These data suggest that patients with advanced cirrhotic-stage primary sclerosing cholangitis are at increased risk for developing hepatocellular carcinoma and should be screened for hepatocellular carcinoma as well as for cholangiocarcinoma prior to orthotopic liver transplantation.

A candidate gene for hereditary haemochromatosis, HLA-H, has recently been presented. Two missense mutations in the HLA-H gene sequence are predicted to account for nearly 90% of all cases of the disease. The aim of this study was to correlate the presence of these missense mutations with the expressivity of the disease, as assessed by standard biochemical evaluation of serum iron parameters. Detection of the known mutations in haemochromatosis, Cys282Tyr and His63Asp, was undertaken in a large pedigree showing variable expression of the disease in successive generations. In three sibs with overt disease (one male, two female, aged 50 to 53 years), homozygosity for the predominant G to A transition (Cys282Tyr) in HLA-H was detected. However, homozygosity for this mutation was also detected in an asymptomatic male sib, aged 50, harbouring an identical genotype. The finding of an asymptomatic homozygous Cys282Tyr subject, haplo-identical to affected sibs, indicates that clinical expression of symptomatic disease is variable, even in middle aged Cys282Tyr homozygotes. This has profound implications for the future use of genetic screening for haemochromatosis.

Obsessive compulsive disorder (OCD) is a common illness, characterized by anxiety-provoking thoughts and the need to perform rituals. OCD is most commonly treated with a class of pharmacological agents known as serotonin reuptake inhibitors (SRIs). SRIs block the reuptake of serotonin (5-HT) into the presynaptic neuron, a process mediated by the serotonin transporter (5-HTT). The successful use of SRIs in OCD has led to the hypothesis that 5-HTT may play a pivotal role in the pathogenesis of OCD. We decided to study this hypothesis from a genetic perspective, because family and twin studies suggest that there is a strong genetic component to OCD. In addition, the sequence of the gene for 5-HTT is available, and a 44-bp insertion/deletion polymorphism has been detected in the promoter region of the gene. There is evidence that this polymorphism alters expression of the transporter protein. We typed 72 OCD patients and 72 matched controls, and found no statistically significant difference between the two groups (chi 2 = 4.319, P = 0.115, 2 d.f.). We observed however a trend towards increased homozygosity in the patient group. We also rated (retrospectively) the patients' clinical responses to SRIs. No association was observed between these ratings and the promoter region polymorphism in the serotonin transporter gene. Given the pharmacological evidence favoring a role for 5-HTT in OCD and SRI response, further genetic evaluation of the serotonin transporter in OCD is indicated.

<h4>Background and aims</h4>Neural Cell Adhesion Molecule (NCAM) is a well-characterized member of the immunoglobin superfamily. The structure of NCAM is similar to the tumor suppressor Deleted in Colon Carcinoma (DCC). NCAM has been found in some epithelial tissues and plays a role in tumorigenesis of some cancers. The purpose of the present study was to determine if NCAM is present in normal human colon. Once its presence was established, its function as a tumor suppressor was investigated.<h4>Methods</h4>Colon tumors and normal proximal margins were processed for reverse transcription-polymerase chain reaction (RT-PCR) of the NCAM-180 message. Immunohistochemistry of the tissue was performed to determine the distribution of NCAM.<h4>Results</h4>RT-PCR analysis demonstrated the presence of the NCAM-180 kD isoform in normal colonic epithelia. Immunohistochemistry showed NCAM on the basolateral surface of colonic epithelial cells of the villous tips. Tumors from 15 patients followed up for 4 years were studied. All seven tumors expressing NCAM-180 were from patients having a benign clinical course. Seven of eight tumors that lacked NCAM-180 were associated with aggressive clinical behaviors (presenting with obstruction, perforation or metastatic disease, or patient death within 18 months of presentation). The sole exception was in a villous adenoma excised from a patient who has had multiply recurrent polyps on follow-up.<h4>Conclusion</h4>We conclude that like DCC, NCAM is an important colonic adhesion molecule that functions as a tumor suppressor.

The recently described association between haemochromatosis and mutations in the HFE or HLA-'H' gene has prompted the need for a simple and rapid genetic test capable of detecting multiple mutations simultaneously. Heteroduplex analysis, a new diagnostic technique, fulfills such criteria and we have investigated the potential for the detection of the Cys282Tyr mutation. 100 subjects were genotyped using the heteroduplex approach. The results showed clear distinction between individuals who did not carry the mutation, individuals who were heterozygous for the mutation and homozygous individuals. Heteroduplex results obtained by both silver staining and capillary electrophoresis showed 100% concordance with those obtained by restriction digestion of PCR product.

Embryonic retinal ganglion cell (RGC) axons must extend toward and grow through the optic disc to exit the eye into the optic nerve. In the embryonic mouse eye, we found that immunoreactivity for the axon guidance molecule netrin-1 was specifically on neuroepithelial cells at the disk surrounding exiting RGC axons, and RGC axons express the netrin receptor, DCC (deleted in colorectal cancer). In vitro, anti-DCC antibodies reduced RGC neurite outgrowth responses to netrin-1. In netrin-1- and DCC-deficient embryos, RGC axon pathfinding to the disc was unaffected; however, axons failed to exit into the optic nerve, resulting in optic nerve hypoplasia. Thus, netrin-1 through DCC appears to guide RGC axons locally at the optic disc rather than at long range, apparently reflecting the localization of netrin-1 protein to the vicinity of netrin-1-producing cells at the optic disc.

We selected 42 patients with bipolar disorder type I (BPI) and 40 healthy controls for genetic analysis of DNA polymorphisms in the serotonin receptor 2c (5-HTR2c) and serotonin transporter (5-HTT) genes. No significant associations were found in the total patient sample. However, when the individuals were divided according to gender, trends for association with both polymorphisms (P = 0.051 for 5-HTR2c and P = 0.049 for 5-HTT) in female patients were observed. These results suggest that variations in these genes may be responsible for a minor increase in susceptibility for bipolar disorder in women.

A patient with colon carcinoma complicated by polycythemia vera (PV) who underwent a partial colectomy concomitant with prophylactic perioperative treatment resulting in successful outcome is herein described. Seven weeks after the cessation of the latest exacerbation of PV, a partial colectomy was performed. In order to prevent the development of disseminated intravascular coagulation and thrombotic complications, the following perioperative treatment was performed: administration of gabexate mesilate (2,000 mg/day), fresh frozen plasma (300 ml/day), heparin (5,000 IU/day) for 7 days and anti-thrombin-III for 4 days, and a potent antibiotic therapy for 12 days and graded elastic bandages around the bilateral lower extremities for 14 days. As a result, an uneventful postoperative course was achieved. The present case suggests that these treatments are useful in the perioperative management of PV patients.

Recent studies have shown that hereditary hemochromatosis (HH) is likely to be caused by homozygosity for a Cys282Tyr mutation in the HFE gene located 4.5 Mb telomeric to HLA-A. Population studies of this polymorphism are facilitated by the fact that the Cys282Tyr mutation creates a Rsal restriction site. We have studied the codon 282 (Cys/Tyr) polymorphism in different ethnic groups. In agreement with previous observations the Tyr allele appeared to be rare or absent in Asiatic (Indian, Chinese) populations. The highest allele frequency (7.5%) was found in Swedes. Saamis (2%) and Mordvinians (1.8%) had significantly lower frequencies of the Tyr allele. Comparisons with allele frequencies based on prevalence estimates of HH showed some disagreements with the RFLP data, particularly in Finns. The newly described HFE marker provides a new approach to the screening of HH as well as studies of the relationship between the HFE Tyr allele and different disorders including cancer.

DCC is a member of the immunoglobulin superfamily of cell adhesion molecules, whose role in the function of the adult nervous system is unknown. DCC mRNA expression was studied in adult rat dorsal hippocampal sections using in situ hybridization histochemistry. High levels of DCC transcript were detected in hippocampus and medial habenula, whereas lower mRNA expression was found in cerebral cortex, hypothalamus and thalamus. The higher relative expression of DCC mRNA in hippocampus, compared with the remainder of the brain was confirmed using RT-PCR analysis. These data confirm the presence of DCC mRNA in adult rat brain and indicate that DCC mRNA is differentially expressed between forebrain regions, suggesting a role for DCC in the function of the adult rat central nervous system.

The use of low molecular weight organic compounds to induce dimerization or oligomerization of engineered proteins has wide-ranging utility in biological research as well as in gene and cell therapies. Chemically induced dimerization can be used to activate intracellular signal transduction pathways or to control the activity of a bipartite transcription factor. Dimerizer systems based on the natural products cyclosporin, FK506, rapamycin, and coumermycin have been described. However, owing to the complexity of these compounds, adjusting their binding or pharmacological properties by chemical modification is difficult. We have investigated several families of readily prepared, totally synthetic, cell-permeable dimerizers composed of ligands for human FKBP12. These molecules have significantly reduced complexity and greater adaptability than natural product dimers. We report here the efficacies of several of these new synthetic compounds in regulating two types of protein dimerization events inside engineered cells--induction of apoptosis through dimerization of engineered Fas proteins and regulation of transcription through dimerization of transcription factor fusion proteins. One dimerizer in particular, AP1510, proved to be exceptionally potent and versatile in all experimental contexts tested.

A homogeneous DNA diagnostic assay based on template-directed primer extension detected by fluorescence resonance energy transfer, named template-directed dye-terminator incorporation (TDI) assay, has been developed for mutation detection and high throughput genome analysis. Here, we report the successful application of the TDI assay to detect mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the human leukocyte antigen H (HLA-H) gene, and the receptor tyrosin kinase (RET) protooncogene that are associated with cystic fibrosis, hemochromatosis, and multiple endocrine neoplasia, type 2, respectively. Starting with total human DNA, the samples are amplified by the PCR followed by enzymatic degradation of excess primers and deoxyribonucleoside triphosphates before the primer extension reaction is performed. All these standardized steps are performed in the same tube, and the fluorescence changes are monitored in real time, making it a useful clinical DNA diagnostic method.

The majority of iron for essential mammalian biological activities such as erythropoiesis is thought to be reutilized from cellular hemoproteins. Here, we generated mice lacking functional heme oxygenase 1 (Hmox1; EC 1.14.99.3), which catabolizes heme to biliverdin, carbon monoxide, and free iron, to assess its participation in iron homeostasis. Hmox1-deficient adult mice developed an anemia associated with abnormally low serum iron levels, yet accumulated hepatic and renal iron that contributed to macromolecular oxidative damage, tissue injury, and chronic inflammation. Our results indicate that Hmox1 has an important recycling role by facilitating the release of iron from hepatic and renal cells, and describe a mouse model of human iron metabolic disorders.

Colorectal cancer is a significant cause of morbidity and mortality in Western populations. This cancer develops as a result of the pathologic transformation of normal colonic epithelium to an adenomatous polyp and ultimately an invasive cancer. The multistep progression requires years and possibly decades and is accompanied by a number of recently characterized genetic alterations. Mutations in two classes of genes, tumor-suppressor genes and proto-oncogenes, are thought to impart a proliferative advantage to cells and contribute to development of the malignant phenotype. Inactivating mutations of both copies (alleles) of the adenomatous polyposis coli (APC) gene--a tumor-suppressor gene on chromosome 5q--mark one of the earliest events in colorectal carcinogenesis. Germline mutation of the APC gene and subsequent somatic mutation of the second APC allele cause the inherited familial adenomatous polyposis syndrome. This syndrome is characterized by the presence of hundreds to thousands of colonic adenomatous polyps. If these polyps are left untreated, colorectal cancer develops. Mutation leading to dysregulation of the K-ras protooncogene is also thought to be an early event in colon cancer formation. Conversely, loss of heterozygosity on the long arm of chromosome 18 (18q) occurs later in the sequence of development from adenoma to carcinoma, and this mutation may predict poor prognosis. Loss of the 18q region is thought to contribute to inactivation of the DCC tumor-suppressor gene. More recent evidence suggests that other tumor-suppressor genes--DPC4 and MADR2 of the transforming growth factor beta (TGF-beta) pathway--also may be inactivated by allelic loss on chromosome 18q. In addition, mutation of the tumor-suppressor gene p53 on chromosome 17p appears to be a late phenomenon in colorectal carcinogenesis. This mutation may allow the growing tumor with multiple genetic alterations to evade cell cycle arrest and apoptosis. Neoplastic progression is probably accompanied by additional, undiscovered genetic events, which are indicated by allelic loss on chromosomes 1q, 4p, 6p, 8p, 9q, and 22q in 25% to 50% of colorectal cancers. Recently, a third class of genes, DNA repair genes, has been implicated in tumorigenesis of colorectal cancer. Study findings suggest that DNA mismatch repair deficiency, due to germline mutation of the hMSH2, hMLH1, hPMS1, or hPMS2 genes, contributes to development of hereditary nonpolyposis colorectal cancer. The majority of tumors in patients with this disease and 10% to 15% of sporadic colon cancers display microsatellite instability, also know as the replication error positive (RER+) phenotype. This molecular marker of DNA mismatch repair deficiency may predict improved patient survival. Mismatch repair deficiency is thought to lead to mutation and inactivation of the genes for type II TGF-beta receptor and insulin-like growth-factor II receptor. Individuals from families at high risk for colorectal cancer (hereditary nonpolyposis colorectal cancer or familial adenomatous polyposis) should be offered genetic counseling, predictive molecular testing, and when indicated, endoscopic surveillance at appropriate intervals. Recent studies have examined colorectal carcinogenesis in the light of other genetic processes. Telomerase activity is present in almost all cancers, including colorectal cancer, but rarely in benign lesions such as adenomatous polyps or normal tissues. Furthermore, genetic alterations that allow transformed colorectal epithelial cells to escape cell cycle arrest or apoptosis also have been recognized. In addition, hypomethylation or hypermethylation of DNA sequences may alter gene expression without nucleic acid mutation.