The myocardium in congestive heart failure

It is now apparent that the myocardium in patients with congestive heart failure (CHF) is not normal, because important structural and molecular changes modify function in these hearts. It appears likely that the myocardium in these patients with CHF becomes unable to provide enough chemical energy to meet its mechanical requirements. If this interpretation is correct, the resulting condition of "energy starvation" would have several important implications for therapy. For example, inotropic stimulation, by increasing energy expenditure, could contribute to the progressive myocardial cell death that characterizes end-stage cardiac hypertrophy. Conversely, the reduction in myocardial contractility that develops in the chronically over-loaded heart reduces myocardial energy expenditure, and changes in the expression of myosin isoforms improve cardiac efficiency. Therefore, an important goal of therapy in the patient with CHF is to reduce energy expenditure by unloading the failing heart and, in some cases, by administration of negative inotropic drugs.     

Local circuits and ocular dominance columns in monkey striate cortex

The relationships between ocular dominance columns and intrinsic cortical circuitry were examined in brain slices prepared from the striate cortex of macaques. Ocular dominance columns in layer 4C beta were visualized in vitro following anterograde transport of rhodamine injected into the lateral geniculate nucleus in vivo. The axonal and dendritic arborizations of individual layer 4C beta cells were revealed by intracellular fluorescent dye injections. Both qualitative observations and quantitative analysis showed that the dendrites of cells close to borders remained preferentially, although not absolutely, in the "home" column (the column containing the cell body). Thus, the segregated pattern of afferent input appears to have considerable influence on the pattern of dendritic arbors. Similarly, while axon collaterals within layer 4C beta could cross into the adjacent column, their limited lateral spread produced arbors that remained primarily within the home column. The terminal arbors of collaterals that travelled from layer 4C beta to layer 3 had a larger lateral spread, and the termination pattern appeared to be independent of column borders. Thus, our observations indicate that, while the course of many layer 4C beta dendrites appears to be guided by columnar boundaries as defined by geniculate afferents, there exist morphological substrates for intercolumnar interactions even between 4C beta cells. Intercolumnar interactions are seen more commonly in layer 3, however, where larger, denser axon arbors originating from 4C beta cells can freely cross ocular dominance column boundaries.     

Nodular glomerulopathy associated with nonamyloidotic kappa light chain deposits and excess immunoglobulin light chain synthesis

A nodular glomerulopathy characterized by mesangial deposits of monoclonal kappa light chains was detected by immunofluorescence in a renal biopsy from a patient with proteinuria and hypertension. These nodules lacked the tinctorial and morphologic features of amyloid. Ultrastructurally, the nodules contained electron-dense granular deposits as well as fibrils in parallel arrangement. The fibrils measured 110-140 A in diameter. They were consistent in size with amyloid fibrils. However, they differed in lacking the randomly oriented network of typical amyloid fibrils and more closely resembled fibrils intrinsic to mesangial matrix. The patient had no bone marrow or X-ray evidence of myeloma and no evidence of free monoclonal light chains in serum or concentrated urines. Biosynthetic studies of the patient's bone marrow cells demonstrated unbalanced immunoglobulin synthesis with excess production of monoclonal kappa light chains. These observations suggest that the observed glomerulopathy results from direct deposition of monoclonal light chains. Deposits with kappa light chain determinants have been found in 7 other patients with similar nodular glomerulopathies, 4 of whom had diagnosed clinical myeloma. The lesion of nonamyloidotic nodular glomerulopathy previously described in 19 patients, nor examined by immunopathologic techniques or not shown to contain light chain determinants, may have a similar pathogenesis.     

Antibody-dependent cellular cytotoxicity (ADCC)-mediated destruction of human immunodeficiency virus (HIV)-coated CD4+ T lymphocytes by acquired immunodeficiency syndrome (AIDS) effector cells

The acquired immunodeficiency syndrome (AIDS) is defined in clinical terms by the development of Kaposi's sarcoma and/or severe opportunistic infections in persons without predisposing conditions. A hallmark of the syndrome has been a decrease in the number of CD4⁺ T helper cells. The reduction in the frequency of the CD4⁺ lymphocytes has been postulated to be primarily the result of human immunodeficiency virus (HIV) tropism and cytophathogenicity for the T-cell subset. Yet only a small percentage of cells is actually infected with HIV. Recently, we provided evidence indicating that AIDS patients' natural killer cells can mediate normal levels of antibody-dependent cellular cytotoxicity (ADCC) despite exhibiting a defect in natural killer (NK) effector function (J Immunol 139:55, 1987). This finding prompted us to investigate whether AIDS patients' effector cells could mediate ADCC against circulating CD4⁺ T cells infected with or expressing HIV antigen. The findings reported herein demonstrate that AIDS effector cells can mediate lysis of CEM (CD4⁺ T-cell line) coated with HIV protein in the presence of HIV-specific antibody. Lysis was specific, as non-HIV-coated CEM or the addition of HIV-negative serum resulted in no lysis. We then examined HIV-coated peripheral blood-derived CD4⁺ T lymphocytes as targets in ADCC. We demonstrate that in the presence of HIV-specific antibody, HIV-coated CD4⁺ T lymphocytes serve as targets for ADCC by AIDS effector cells. The lytic activity obtained with AIDS effector cells was comparable to that obtained with normal effector cells. These results demonstrate that AIDS effector cells can mediate ADCC against HIV-coated CD4⁺ T lymphocytes and suggest that ADCC may play a rolein vivo in the pathogenesis of AIDS.     

Chromosome mapping of cell membrane antigens expressed on activated B cells

Hybrids formed by fusion of either human acute lymphoblastic or chronic lymphocytic leukemia cells and the mouse myeloma P3.X63.Ag8/653 have been used to show that the expression of two cell surface antigens, Bp37 and p76, associated with B cell activation and detected by the monoclonal antibodies BB1 and BB2, respectively, segregate with human chromosomes 12 and 19, respectively. Another antigen expressed on activated B cells (p24) also maps to chromosome 12 (Katz et al., Eur. J. Immunol. 1984. 13: 1008) which is of interest in the light of the frequent involvement of this chromosome in certain B cell leukemias and lymphomas.     

Immunization of rabbits with a modified vaccinia Ankara recombinant virus bearing the HIV envelope antigen on its outer membrane

Modified vaccinia virus Ankara (MVA) is a highly attenuated strain of vaccinia virus, which propagates efficiently in chicken embryo fibroblasts but fails to complete its growth cycle in many types of mammalian cells. We constructed a recombinant virus MVA/EK5, which has a chimeric gene encoding for the extracellular domain of the HIV envelope protein fused to the cytoplasmic and transmembrane domain of the B5R protein of vaccinia virus. The fused HIV envelope antigen was expressed in the African green monkey kidney BS-C-1 cells infected with the recombinant virus. This virus, which had been grown in chicken embryo fibroblasts, induced in rabbits antibodies against the HIV envelope antigen, in addition to those against poxvirus.     

Rapid activation of glycogen synthase and protein phosphatase in human skeletal muscle after isometric contraction requires an intact circulation

The effects of isometric contraction (66% of maximal force) and recovery on glycogen synthase fractional activity (GSF) in human skeletal muscle have been studied. Biopsies were taken from the quadriceps femoris muscle at rest, at fatigue and 5 min postexercise on two occasions: after one of the contractions, the circulation to the thigh was occluded during the 5 min recovery (OCC), and after the other contraction, the circulation was intact (control, CON). During CON, GSF decreased from (mean ± SE) 0.34±0.05 at rest to 0.24±0.02 at fatigue and then increased to 0.74±0.04 at 5 min postexercise; corresponding values for OCC were 0.37±0.04, 0.25±0.04 and 0.48±0.05 (P<0.001 vs. CON for 5 min postexercise only). Compared with the value at fatigue, protein phosphatase activity (PP) increased by 79±16% during CON recovery (P<0.01), whereas no change was observed during OCC recovery. Uridine diphosphate glucose increased by approximately 2.5-fold at fatigue, remained elevated during OCC recovery, but reverted to the preexercise level during CON recovery (P<0.001 vs. OCC recovery). Glucose 6-P increased approximately 5-fold at fatigue and was higher at 5 min postexercise in OCC vs. CON recovery (8.6±1.5 vs. 4.1±0.9 mmol/kg dry wt; P<0.01). It is concluded that the rapid increase in GSF after intense exercise with an intact circulation may be at least partly attributed to an increase in the specific activity of PP. The increase in GSF during recovery in OCC may be at least partly attributed to the high glucose 6-P content in vivo, which enhances the substrate suitability of GS for PP. Thus, separate mechanisms exist for the activation of PP and GS during recovery from intense short term exercise.     

Trisomy X in a female member of a family with X linked severe combined immunodeficiency: implications for carrier diagnosis.

We describe a family affected by X linked severe combined immunodeficiency (SCIDX1) in which genetic prediction of carrier status was made using X chromosome inactivation studies together with limited genetic linkage analysis. Linkage studies in this family showed a confusing pattern of inheritance for the X chromosome. A female with a random pattern of X chromosome inactivation in her T cells appeared to have inherited an X chromosome with four recombinations within 10 cM. The odds of this happening in a single meiotic event make this an unlikely explanation. Data obtained from studying the X chromosomes of her two unaffected sons showed that this could be explained simply on the basis of her having inherited three alleles each of the relevant polymorphic DNA loci. We used fluorescent in situ hybridisation (FISH) to confirm that this person had inherited three complete X chromosomes. Thus, although the results from X chromosome inactivation analysis indicated that this subject was not a carrier of the affected chromosome, FISH and genetic linkage analysis showed clearly that the affected chromosome had been inherited. The implications of this finding for diagnosis of carrier status in this family and for other families with X linked inherited immunodeficiencies is discussed.     

The osmotic behaviour of toad skin epithelium (Bufo viridis)

The effect of saline adaptation on the intracellular Na, K, Cl, P concentrations and dry weight content of the toad skin epithelium (Bufo viridis) was studied using the technique of electron microprobe analysis. The measurements were performed on isolated abdominal skins either directly after dissection or after additional incubation in Ussing-type chambers.Adaptations of the toads to increasing NaCl concentrations for 7 days resulted in increased blood plasma osmolarity and a parallel increase in the cellular electrolyte, P and dry weight concentrations of the epithelium, the K increase representing the most significant fraction of the intracellular osmolarity increase. No evidence was obtained to show that the nucleus and cytoplasm reacted differently from each other and all living epithelial cell types basically showed the same response.Incubation of the isolated skins under control conditions showed a drastic inhibition of the transepithelial Na transport after adaptation to high salinities. In spite of the large variations in the transport rate almost identical intracellular electrolyte concentrations were observed. In tap water adapted toads the average cellular concentrations were 8.8 mmole/kg wet weight for Na, 109.6 for K, 41.5 for Cl, and 135.3 for P, respectively. Incubation of the skin with Ringer's solution of different osmolarities demonstrated that the epithelial cells are in osmotic equilibrium with the inner bathing solution. The results are consistent with the view that the osmotic adaptation is mainly accomplished by the movement of water.This work was supported by grants from the Deutsche Forschungsgemeinschaft and the Stiftung Volkswagenwerk     

IVIg therapy in autoimmunity and related disorders: our experience with a large cohort of patients

Intravenous immunoglobulin (IVIg) is used to treat a number of immune-deficiencies and autoimmune diseases. It has been shown that IVIg contains anti-idiotypic antibodies, which explains its immunomodulatory action.In murine models, recent investigations have demonstrated that IVIg can prevent and reduce the affliction by systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS) and scleroderma. Relevant disease-specific fractions of IVIg were able to reproduce and even enhance the therapeutic effect in a murine model.IVIg treatment before tumor resection in rodents inoculated with melanoma and sarcoma cells dramatically improved the cure rate (50%) in comparison to the control group (0%).In patients affected by SLE, several clinical manifestations responded to IVIg treatment including serositis, hematological manifestations, treatment-resistant nephritis and central nervous system involvement. Similarly, in women with recurrent fetal loss due to APS, IVIg was able to diminish the abortion rate. Vasculitides such as Churg-Strauss' and Wegener's and skin fibrosis in patients affected by scleroderma improved after IVIg treatment. In agreement with in vitro investigations, prolonged survival has been noted in cancer patients treated with IVIg.We suggest that in the presence of a steroid and immunosuppressive-resistant autoimmune disease, IVIg is a rational and safe choice.