Familial occurrence of discrete subaortic membrane

The first case of multiple family members with discrete subaortic membrane and no other congenital defects is presented. One family member presents with findings suggesting a forme fruste of this disease. Increased surveillance of family members of individuals with discrete subaortic membrane is warranted, as the clinical findings of mild subaortic obstruction may be indistinguishable from those of an innocent flow murmur.

Functional neurological outcome in leukaemic children receiving repeated cranial irradiation

Long-term outcome defined by educational or employment history has been recorded in a group of children with acute lymphoblastic leukaemia (ALL) who received cranial radiotherapy at some stage prior to TBI conditioned bone marrow transplant (BMT). Median follow-up in 24 survivors of 69 consecutive patients was 4 years and 2 months. Individual risk factors for poor functional outcome were considered, including calculations of biological effective radiation doses. There was no incidence of CNS treatment-related mortality. All survivors are in normal school or employment, although three who had CNS relapse are receiving remedial teaching. No individual risk factors could be identified but the worst outcome was seen in children who were of young age at the time of initial treatment, who suffered CNS relapse and who had received the highest total dose of cranial irradiation.

Rheumatoid factors from the peripheral blood of two patients with rheumatoid arthritis are genetically heterogeneous and somatically mutated

We report the DNA sequences of the heavy and light chain immunoglobulin genes of 11 monoclonal rheumatoid factor (RF)-secreting lines derived from the peripheral blood of two patients with rheumatoid arthritis (RA). It is evident from immunogenetic analysis of these lines that RA-associated RF activity can arise from a wide variety of heavy and light chain genes and gene combinations. Although the RF response from our two patients shows a bias in gene usage toward those genes used to encode monoclonal RF, particularly VkIII, relatively few of these RFs are reactive with the monoclonal antiidiotypes 6B6.6 and 17.109 that define VkIII germline-encoded light chains and the loss of this idiotypic reactivity is clearly related to somatic mutation. Finally, RFs derived from peripheral blood of RA patients show a similar heterogeneity of epitope binding to Fc as that seen for synovium-derived RF and some are clearly different in binding specificity from the restricted RF population found in patients with B cell malignancies. Somatic mutations as well as different VH/VL combinations contribute to the heterogeneity in the binding patterns of these RA-derived RF.

Expression of rheumatoid factor idiotypes 17.109, 6B6.6 and 4C9 in the sera of Pima Indians

This study was undertaken to determine whether the expression of 17.109, 6B6.6 and 4C9 rheumatoid factor (RF) idiotypes is predictive of the development of rheumatoid arthritis (RA) and whether the RF response is idiotypically restricted in an inbred population of Pima Indians who have a genetic predisposition for the disease. Serial sera were obtained from 25 subjects who developed RA and 25 RF-positive subjects who did not develop RA over the course of a longitudinal community health survey. RF titers and titers of the RF-associated idiotypes 17.109, 6B6.6 and 4C9 were determined by ELISA, and the relationship between 6B6.6 and 4C9 was analyzed by cross-absorption studies. Expression of the three RF-associated idiotypes was found in both the subjects who developed RA and those who did not. The amount of idiotype expressed was variable, but a few subjects in both groups had high levels indicative of an oligoclonal RF response. Reactivity with 6B6.6 and 4C9 antiidiotypes overlapped, with 4C9 appearing to mark a broader spectrum of RF than 6B6.6. Thus, even in an inbred and genetically predisposed population, the RF-associated antiidiotypes studied here did not identify a dominant idiotypic response and were no better markers for the development of RA than was RF itself.

Mapping studies reveal unique epitopes on IgG recognized by rheumatoid arthritis-derived monoclonal rheumatoid factors

We have used chimeric IgG antibodies and their genetically engineered variants prepared by a combination of site-directed mutagenesis and exon exchange to define the structure(s) on IgG recognized by monoclonal rheumatoid factor (RF) autoantibodies from rheumatoid arthritis (RA) patients. Nineteen RF produced by EBV-transformed cell lines from the synovium or blood of RA patients were analyzed. Their binding patterns differ significantly from those seen with RF obtained from patients with Waldenstrom's macroglobulinemia (WMac). Half of the RA-derived RF bound IgG1, 2, and 4, but not 3 (Ga specificity), the common pattern in WMac. However, heterogeneity in fine specificity within the Ga reactivity pattern was observed. Moreover, seven others bound all four IgG subclasses, a pattern observed for only one WMac-derived RF from a patient who also had RA. Three RF had subclass specificities unlike any observed with WMac-derived RF. Most RA-derived RF bound IgG at a discontinuous epitope comprised of residues from both the CH2 and CH3 H chain constant regions. However, unlike any WMac-derived RF, one RA-derived RF bound IgG in CH2, another in CH3, and a third at an undetermined site outside of the CH2-CH3 interface. Some RA-derived RF bound aglycosylated IgG4 less well than glycosylated IgG4, suggesting that the carbohydrate moiety was important in establishing their binding epitope in CH2. These studies demonstrate that the repertoire of RF expressed by RA patients contains some unique binding specificities for IgG epitopes not found among our panel of WMac-derived RF. Our results therefore call into question whether WMac-derived RF with their limited diversity are appropriate models for disease-related RF. In addition, RF with their multiple specificities can serve as probes of antibody structure.

A cDNA clone for a pathogenesis-related protein 1 from barley

A barley cDNA clone (PRb-1) corresponding to an mRNA differentially induced in resistant compared to susceptible barley cultivars by powdery mildew infection was isolated and characterised. The deduced amino acid sequence revealed 24 amino acids comprising the signal peptide and 140 amino acids of the mature peptide (15 kDa). This showed close homology to PR-1-like proteins, which have been isolated from maize, tobacco, tomato and Arabidopsis thaliana. Northern blot analysis showed accumulation of the corresponding mRNA 12 h after inoculation of resistant barley cultivars with Erysiphe graminis. Increased expression of the PRb-1 gene was also observed in resistant compared with near-isogenic susceptible barley plants following treatment with ethylene, salicylic acid, methyl jasmonate and 2,6-dichloro-isonicotinic acid.

Mapping studies reveal unique epitopes on IgG recognized by rheumatoid arthritis-derived monoclonal rheumatoid factors

We have used chimeric IgG antibodies and their genetically engineered variants prepared by a combination of site-directed mutagenesis and exon exchange to define the structure(s) on IgG recognized by monoclonal rheumatoid factor (RF) autoantibodies from rheumatoid arthritis (RA) patients. Nineteen RF produced by EBV-transformed cell lines from the synovium or blood of RA patients were analyzed. Their binding patterns differ significantly from those seen with RF obtained from patients with Waldenstrom's macroglobulinemia (WMac). Half of the RA-derived RF bound IgG1, 2, and 4, but not 3 (Ga specificity), the common pattern in WMac. However, heterogeneity in fine specificity within the Ga reactivity pattern was observed. Moreover, seven others bound all four IgG subclasses, a pattern observed for only one WMac-derived RF from a patient who also had RA. Three RF had subclass specificities unlike any observed with WMac-derived RF. Most RA-derived RF bound IgG at a discontinuous epitope comprised of residues from both the CH2 and CH3 H chain constant regions. However, unlike any WMac-derived RF, one RA-derived RF bound IgG in CH2, another in CH3, and a third at an undetermined site outside of the CH2-CH3 interface. Some RA-derived RF bound aglycosylated IgG4 less well than glycosylated IgG4, suggesting that the carbohydrate moiety was important in establishing their binding epitope in CH2. These studies demonstrate that the repertoire of RF expressed by RA patients contains some unique binding specificities for IgG epitopes not found among our panel of WMac-derived RF. Our results therefore call into question whether WMac-derived RF with their limited diversity are appropriate models for disease-related RF. In addition, RF with their multiple specificities can serve as probes of antibody structure.

A vasoactive intestinal peptide antagonist inhibits non-small cell lung cancer growth

The most prevalent lung cancer, non-small cell lung cancer (NSCLC) has receptors for vasoactive intestinal peptide (VIP). Here the effects of a VIP antagonist (VIP-hyb) on NSCLC growth were investigated. In vivo, when VIPhyb (10 micrograms, s.c.) was daily injected into nude mice, xenograft formation was significantly inhibited by approximately 80%. In vitro, VIP (100 nM) stimulated colony formation approximately 2-fold, whereas 1 microM VIPhyb inhibited colony formation by approximately 50% when adenocarcinoma cell line NCI-H838 was used. The attenuation of tumor proliferation is receptor mediated, as VIPhyb inhibited specific 125I-labeled VIP binding to cell lines NCI-H157 and NCI-H838 with an IC50 of 0.7 microM. VIP (10 nM) increased the cAMP levels 5-fold when cell line NCI-H838 was used, and 10 microM VIPhyb inhibited the increase in cAMP caused by VIP. Northern blot analysis and radioimmunoassays have shown VIP mRNA and VIP-like immunoreactivity in NSCLC cells. These data suggest that VIP may be a regulatory peptide in NSCLC and that VIPhyb is a VIP receptor antagonist that inhibits proliferation.

Evaluation of 50 consecutive segmental hepatic resections

The development of increasingly sensitive imaging techniques along with improved follow-up and screening of high-risk patients has led to hepatic tumors, both primary and secondary, being detected while still at an early stage. Improved understanding of hepatic anatomy along with advances in surgical technique has led to the ability to undertake hepatic resections based on the segmental hepatic anatomy as described by Couinaud. The purpose of this paper is to assess the safety, technique, and oncologic efficacy of segmental hepatic resection. Fifty consecutive patients undergoing segmental hepatic resection during a 3-year time period ending in January 1992 were reviewed. Parametric statistical analysis was undertaken using Student's t-tests. Overall mortality was 2% with a morbidity rate of 8%. Transfusion requirements were 1 +/- 1.5 U; however, cirrhotic patients showed a significantly increased transfusion requirement of 2.0 +/- 1.3 U versus 0.7 +/- 1.3 U (p = 0.03). Sixty percent of patients required no transfusion at all. The mean duration of inflow occlusion was 42 +/- 17 minutes. Resection margins were clear of tumor by greater than 1 cm in 48 of 50 patients. Segmental hepatic resection is a safe and effective technique that occasionally may offer advantages over formal resection. Some aspects of the technique are reviewed.

21-day schedule oral etoposide in children--a feasibility study

To determine the feasibility and toxicity of prolonged oral etoposide in children, 22 patients with relapsed or refractory disease were commenced on etoposide 50-100 mgs/m2 per day for 21 days. A second course was administered after full blood count recovery, followed by disease reassessment. In total, 72 courses were evaluable for toxicity, with 10% of completed courses complicated by febrile neutropenia. 15 patients were evaluable for response, with 1 partial response, 10 stable disease and 4 progressive disease. This schedule was well tolerated with acceptable toxicity when doses of less than 80 mg/m2/day were administered and warrants further evaluation.

Immune tolerance to a defined heterologous antigen after intrasplenic hepatocyte transplantation: implications for gene therapy

Development of a host immune response against gene products expressed by genetically modified cells could be a serious limitation for gene therapy. During examination of whether site-specific differences in antigen presentation could regulate the host immune response, we observed an absence of antibodies against hepatitis B virus surface antigen (HBsAg) when HBsAg producing transgenic hepatocytes were transplanted into the spleen. Intrasplenic transplantation resulted in translocation of a large number of cells into the portal vascular bed and liver sinusoids. In these recipients, HBsAg secreted by the transplanted hepatocytes circulated indefinitely in the blood. In contrast, subcutaneous or intraperitoneal transplantation of the transgenic hepatocytes induced an anti-HBs response, followed by clearance of serum HBsAg. Rechallenge with HBsAg in a highly immunogenic form failed to break the tolerance in intrasplenic hepatocyte recipients even though these animals responded to another antigen (keyhole limpet hemocyanin). Immunization with HBsAg in intraperitoneal recipients of HBsAg producing hepatocytes further elevated anti-HBs titers. Our results indicate that hepatocyte transplantation into the portal vascular bed via injection into the spleen can confer immune tolerance to secreted heterologous antigens. This finding should have important implications for human gene therapy as well as for analyzing the mechanisms of immune tolerance.