A replication-deficient rSV40 mediates liver-directed gene transfer and a long-term amelioration of jaundice in gunn rats.

Background & Aims: In the quest for a recombinant viral vector for liver-directed gene therapy that would permit both prolonged and efficient transgene expression in quiescent hepatocytes in vivo and repeated administration, we evaluated a recombinant simian virus 40 (rSV40).

Methods: The rSV40 was generated through replacement of the DNA encoding for the T antigens (Tag) by the coding region of human bilirubin-uridine 5'-diphosphate-glucuronosyl-transferase (BUGT) complementary DNA (SV-hBUGT). Helper-free rSV40 units were generated at infectious titers of 5 x 10(9) to 1 x 10(10) infectious units (IU)/mL in a Tag-producing packaging cell line (COS-7 cells).

Genetic lesions of bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (UGT1A1) causing Crigler-Najjar and Gilbert syndromes: correlation of genotype to phenotype.

Uridine-diphosphoglucuronate glucuronosyltransferases (UGTs) are a family of enzymes that conjugate various endogenous and exogenous compounds with glucuronic acid and facilitate their excretion in the bile. Bilirubin-UGT(1) (UGT1A1) is the only isoform that significantly contributes to the conjugation of bilirubin. Lesions in the gene encoding bilirubin-UGT(1), lead to complete or partial inactivation of the enzyme causing the rare autosomal recessively inherited conditions, Crigler-Najjar syndrome type-1 (CN-1) and type 2 (CN-2), respectively.

Enhancement of retrovirus-mediated gene transfer to rat liver in vivo by infusion of hepatocyte growth factor and triiodothyronine.

Background/aims: Gene transfer using recombinant Moloney murine leukemia viruses (rMoMuLV) requires mitosis of the target cell. Previously, we and others have used partial hepatectomy for induction of hepatocellular proliferation for gene transfer to the liver in vivo by exsanguineous perfusion with rMo-MuLV. We hypothesized that induction of hepatocellular proliferation by combined administration of two hepatocellular mitogens, hepatocyte growth factor (HGF) and triiodothyronine (T3), should permit rMo-MuLV-mediated gene transfer into liver without invasive approaches.

Pregnancies after reconstructive surgery for congenital cervicovaginal atresia.

Eighteen women aged 12 to 20 years with congenital cervicovaginal atresia were treated with a new technique of surgical canalization. All are now having regular menses. Two pregnancies have been achieved, with delivery of viable neonates.

Detection of group- and subgroup-specific antigens of bovine rotaviruses in Bangladesh.

The study was carried out to detect group- and subgroup-specific antigens of bovine rotaviruses. Stool specimens, collected from diarrhoeic calves of the Savar Dairy Farm, Bangladesh, were examined by an enzyme-linked immunosorbent assay, using group- and subgroup-specific monoclonal antibodies. Thirty-three specimens showed specificity for group A rotavirus.

Analysis of human rotavirus G serotype in Bangladesh by enzyme-linked immunosorbent assay and polymerase chain reaction.

Distribution of human rotavirus G serotype was investigated by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) with faecal specimens obtained from children with diarrhoea in Bangladesh. By ELISA, subgroup and G serotype were determined for 59.5% and 28.

Treatment of experimental colitis by oral tolerance induction: a central role for suppressor lymphocytes.

Objective: Inflammatory bowel diseases (IBD) are immune-mediated disorders wherein an imbalance between proinflammatory (Th1) and antiinflammatory (Th2) cytokines is thought to play a role in the pathogenesis. The aim of this study was to test whether induction of oral tolerance to proteins extracted from inflammatory colon alleviates experimental colitis, and whether oral tolerization mediated by suppressor cells can induce immune tolerance.

Methods: Colitis was induced in rats by intracolonic instillation of trinitrobenzenesulfonic acid (TNBS).

Liver-directed gene therapy: promises, problems and prospects at the turn of the century.

Although liver-directed gene therapy arrived later than gene therapy directed at bone marrow cells, intrinsic advantages of the liver as a target organ make it likely that gene therapy for liver diseases will be among the first therapeutically relevant applications of this treatment modality at the onset of the 21st century. Vectorology for gene transfer to the liver is advancing rapidly, and it is safe to predict that gene therapy vehicles that will be in clinical use a decade from now, have not yet been developed. None of the currently available modes of gene transfer to the liver is optimal for all types of applications.

Oral tolerization ameliorates liver disorders associated with chronic graft versus host disease in mice.

In chronic graft versus host disease (cGVHD), an immune attack by transplanted donor lymphocytes results in damage of host target organs. A disbalance between proinflammatory (Th1) and anti-inflammatory cytokines (Th2) plays an important role in the pathogenesis. Immune hyporesponsiveness induced by oral antigen administration has been shown to suppress autoimmunity.

Socio-demographic characteristics of the "unbooked mother".

In a study to investigate the characteristics of the "Unbooked mother", the medical records of 467 patients who presented for delivery with no prenatal care at the obstetric unit of the King Khalid University Hospital (KKUH), Riyadh, during the period 1991 to 1995 were evaluated. For controls, the records of 415 mothers who had pre-natal care in the Unit over the same period were also evaluated. Data pertaining to their socio-demographic characteristics, previous obstetric history, prevalence of pregnancy-related and familial diseases, gestation age at delivery and weights of the babies, were extracted and analysed using odds ratios and 95% confidence intervals (C.

Demographic and fertility variables as determinants of spontaneous abortions in women with previous abortions.

The objective of the study was to examine the demographic and fertility factors that may predispose to spontaneous abortion in women with prior abortion. The study was conducted in King Khalid University Hospital, Riyadh, Saudi Arabia. It included a series of women who aborted their pregnancies over a period of months (January 1; 1992-December 31, 1992).

Regulatory T cells maintain peripheral tolerance to islet allografts induced by intrathymic injection of MHC class I allopeptides.

Although transplantation remains the treatment of choice for diabetes mellitus, immunological rejection of allografts continues to be a major problem. The search for strategies to prevent graft rejection led us to examine if the fate of developing T cells may be influenced by the presence of allo MHC class I peptides in the thymus because T cell receptor-MHC class I/self-peptide interaction regulates thymocyte development. We studied the effects of intrathymic (IT) injection of a short segment of a synthetic immunogenic MHC class I peptide (peptide 2, residues 67-85) of the hypervariable domain of RT1.

Correction of the UDP-glucuronosyltransferase gene defect in the gunn rat model of crigler-najjar syndrome type I with a chimeric oligonucleotide.

Crigler-Najjar syndrome type I is characterized by unconjugated hyperbilirubinemia resulting from an autosomal recessive inherited deficiency of hepatic UDP-glucuronosyltransferase (UGT) 1A1 activity. The enzyme is essential for glucuronidation and biliary excretion of bilirubin, and its absence can be fatal. The Gunn rat is an excellent animal model of this disease, exhibiting a single guanosine (G) base deletion within the UGT1A1 gene.

Mechanism of acquired thymic tolerance induced by a single major histocompatibility complex class I peptide with the dominant epitope: differential analysis of regulatory cytokines in the lymphoid and intragraft compartments.

Background: We have recently shown that intrathymic injection of a combination of immunogenic WAG-derived or Wistar-Furth (WF) (RT1.Au) major histocompatibility complex class I peptides induces acquired systemic tolerance to cardiac and islet allografts in the WF-to-ACI rat combination and therefore hypothesized that identification of the class I peptide dominance may play an important role in the induction of antigen (Ag)-specific tolerance. This study defined the peptide with the dominant epitope among the seven synthetic RT1.

Adenovirus-mediated gene therapy of liver diseases.

Recombinant adenoviruses can infect nondividing cells with high efficiency and are rapidly concentrated in the liver after systemic administration, making them attractive for use in liver-directed gene therapy. However, there are two hurdles to clinical application of these vectors. First, adenoviruses are episomal and have limited life spans within the cell.

Comparative studies of specific acquired systemic tolerance induced by intrathymic inoculation of a single synthetic Wistar-Furth (RT1U) allo-MHC class I (RT1.AU) peptide or WAG (RT1U)-derived class I peptide.

Background: Because T cell receptor-MHC class I/self-peptide interactions regulate T-cell development, the presence of MHC allopeptides in the thymus may influence T-cell tolerance to alloantigens. This hypothesis is supported by our most recent finding that intrathymic (IT) inoculation of nonimmunogenic synthetic peptides derived from "WAG" RT1.A induces tolerance to cardiac allografts in the Wistar-Furth (WF)-to-ACI model.

Does rheumatic fever occur usually between the ages of 5 and 15 years?

It has long been considered that rheumatic fever usually occurs in children between the ages of 5 and 15 years. However, supporting data from the developing countries are insufficient. It is important to know the age of occurrence of rheumatic fever for clinical and public health purposes.

Obstetric outcome in the unbooked mother.

This study aimed at determining the outcome of pregnancy in unbooked mothers with regard to maternal complications and foetal outcome. This retrospective study was based on investigations of medical records of 467 unbooked mothers who presented for delivery at the Obstetrics Unit at King Khalid University Hospital, Riyadh, during the period 1991 and 1992, and 415 booked mothers with regular clinic attendance selected as controls. Data collected from the records included patients' socio-demographic characteristics, past obstetric history, prevalence of pregnancy-related diseases, and data relating to labour, delivery, and foetal outcome.

Oral tolerization to adenoviral proteins permits repeated adenovirus-mediated gene therapy in rats with pre-existing immunity to adenoviruses.

Exposure to wild-type adenoviruses is common in humans and results in immune response against adenoviruses. The pre-existing antibodies and a strong secondary humoral and cellular immune response would interfere with gene transfer using recombinant adenoviral vectors. To test whether the secondary immune response can be abrogated by oral tolerization to adenoviral antigens, we immunized bilirubin-UDP-glucuronosyltransferase (BUGT)-deficient jaundiced Gunn rats with a recombinant adenovirus (5 x 10(9) pfu/rat) expressing the human UDP-glucouronosyltransferase (BUGT1) gene (Ad-hBUGT).