Age-related accumulation of congophilic fibrillar inclusions in endocrine cells

Summary Intracellular fibrillar congophilic inclusions are well known as neurofibrillary tangles in neurons and as Biondi bodies in choroid plexus epithelial cells. Recently similar amyloid-like inclusions in adrenal cortical cells were described (Eriksson and Westermark 1990). This study on 150 adrenal glands confirms these observations. In our material the age-related accumulation of congophilic inclusions starts earlier (in the sixth decade) and reaches a higher incidence (42.7%). We found similar intracellular inclusions in other endocrine organs, for example in the anterior lobe of the pituitary, in the cells of parathyroid glands and in Sertoli cells. The age-related incidence of these fibrillar inclusions in the pituitary was 68%; the co-incidence with interstitial amyloid deposits was 49.5%. Thus the intracellular accumulation of congophilic fibrils in old age is a widespread phenomenon and occurs not only in neurons but also in endocrine cells (adrenal, pituitary and parathyroid glands) and in active secretory cells (choroid plexus and Sertoli cells).     

Modulation of Whole-Cell Currents in Plasmodium Falciparum-Infected Human Red Blood Cells by Holding Potential and Serum

Recent electrophysiological studies have identified novel ion channel activity in the host plasma membrane of Plasmodium falciparum -infected human red blood cells (RBCs). However, conflicting data have been published with regard to the characteristics of induced channel activity measured in the whole-cell configuration of the patch-clamp technique. In an effort to establish the reasons for these discrepancies, we demonstrate here two factors that have been found to modulate whole-cell recordings in malaria-infected RBCs. Firstly, negative holding potentials reduced inward currents (i.e. at negative potentials), although this result was highly complex. Secondly, the addition of human serum increased outward currents (i.e. at positive potentials) by approximately 4-fold and inward currents by approximately 2-fold. These two effects may help to resolve the conflicting data in the literature, although further investigation is required to understand the underlying mechanisms and their physiological relevance in detail.     

Oral DNA vaccination with a plasmid encoding soluble ICAM-1 modulates cytokine expression profiles in nonobese diabetic mice

Adhesion molecules are important for leukocyte extravasation and for the delivery of costimulatory signals in T cell activation. We therefore interfered in the immune process leading to islet inflammation in diabetes prone NOD mice by oral vaccination with plasmid DNA encoding soluble ICAM-1. Female NOD mice were treated orally with ICAM-1, TGF-beta, or control plasmid DNA and received a single injection of cyclophosphamide for synchronization and acceleration of the disease process in the pancreas. Quantitative RT-PCR analysis of pancreatic mRNA showed that cyclophosphamide induced the expression of Th1 cytokines (IFN-gamma and IL-12p40) in vehicle- or control plasmid-treated mice. Treatment with ICAM-1 and TGF-beta DNA resulted in increased levels of IL-10 mRNA in the pancreas, indicating an anti-inflammatory regulatory immune response. Histological analysis of pancreatic islets showed that the DNA treatment did not alter islet infiltration in response to cyclophosphamide. Hence vaccination with the ICAM-1 plasmid had not suppressed leukocyte migration but rather modulated lymphocyte activity, similarly as seen for the TGF-beta-encoding plasmid. Neither of the three plasmids caused recognizable changes in cytokine expression in the small intestine, Peyer's patches, or mesenteric lymph nodes. We conclude that oral vaccination with DNA encoding immunoregulatory molecules such as ICAM-1 and TGF-beta represents an approach for modulating the ongoing inflammatory process in the pancreas of diabetes prone NOD mice.     

Identification and properties of pathways for K+ transport in guinea-pig and rat alveolar epithelial type II cells.

86Rb+ was used to study potassium uptake and efflux in type II pneumocytes freshly isolated from adult guinea-pig and rat lung. Both species exhibited a substantial ouabain-sensitive component of potassium influx. In rats, most of the ouabain-resistant influx was abolished by bumetanide and removal of extracellular chloride elicited no further effect. In contrast, only a proportion of the ouabain-insensitive uptake was inhibitable by bumetanide in guinea-pigs and this species showed an additional component of influx, which was chloride dependent and which was reduced by either the K(+)-H(+)-ATPase inhibitor, omeprazole, or by the stilbene derivative, 4,4'-diisothiocyanostilbene-2,2'-disulphonate (DIDS). The chloride-dependent component was also apparent in efflux experiments in guinea-pigs, but was absent in rats. Ouabain-insensitive ATPase activity was assayed in highly purified apical membranes from guinea-pig type II pneumocytes. This activity was inhibitable by omeprazole (apparent inhibition constant, Ki, was approximately 40 microM), was potassium dependent (apparent activation constant, Ka, was approximately 200 microM) and was doubled by the addition of nigericin. While potassium transport in rat type II cells is adequately accounted for by Na(+)-K(+)-ATPase and Na(+)-K(+)-2Cl- cotransport, our data suggest the additional presence of K(+)-Cl- cotransport and K(+)-H(+)-ATPase in guinea-pig type II pneumocytes. A model of how alveolar subphase acidification may occur is proposed.     

Kinetics of viremia and acute liver injury in relation to outcome of neonatal woodchuck hepatitis virus infection

The kinetics of serum viral responses and acute liver injury were studied during neonatal woodchuck hepatitis virus (WHV) infection in relation to the chronic or resolved outcome. The mean concentrations of serum WHV DNA and surface antigen were significantly higher by week 10 post infection in chronic infections compared to resolving infections, and diverged even further by the time of peak viral load development in serum (week 12). After week 12, these viral markers were detected less frequently with time and at lower concentrations in the resolved outcome. In both outcomes, mean serum activities of hepatic enzymes became increased significantly above baseline by weeks 10-12, peaked at week 14, and normalized by weeks 20-22, thus indicating transient acute liver injury. The increasing liver injury responses were comparable between outcomes at week 12, when serum viral load was markedly higher in the developing chronic infections. This suggested a deficiency in early non-cytolytic control of infection in the chronic outcome. At week 14, liver injury was significantly greater in the resolved outcome and associated with higher mean Fas ligand (FasL) and perforin messenger RNAs (mRNAs) in liver compared to the chronic outcome. This indicated greater immune-mediated killing of infected hepatocytes during resolution. Thus, chronicity as an outcome of neonatal WHV infection develops relatively early during the acute phase of infection due to reduced immune-mediated clearance of infected hepatocytes by both cytolytic and non-cytolytic processes.     

Chromosome aberrations in B-cell chronic lymphocytic leukemia: reassessment based on molecular cytogenetic analysis

In B-cell chronic lymphocytic leukemia (B-CLL) clonal chromosome aberrations are detected in approximately 40–50% of tumors when using conventional chromosome banding analysis. Most studies find trisomy 12 to be the most frequent chromosome aberration, followed by structural aberrations of the long arm of chromosomes 13 and 14. Trisomy 12 and the ”14q+” marker are associated with shorter survival times, while the patients with 13q abnormalities have a favorable outcome, similar to those with a normal karyotype. The development of molecular cytogenetic techniques has greatly improved our ability to detect chromosome aberrations in tumor cells. Using fluorescence in situ hybridization, chromosome aberrations can be detected not only in dividing cells but also in interphase nuclei, an approach referred to as interphase cytogenetics. The prevalence of specific aberrations in B-CLL is currently being reassessed by interphase cytogenetics. By far the most frequent abnormality are deletions involving chromosome band 13q14, followed by deletions of the genomic region 11q22.3-q23.1, trisomy 12, deletions of 6q21-q23, and deletions/mutations of the TP53 tumor suppressor gene at 17p13. The evaluation of the true incidence of these aberrations now provides the basis for more accurate correlations with clinical characteristics and outcome. Deletions/mutations of the TP53 gene have been shown to be associated with resistance to treatment and to be an independent marker for poor survival. 11q deletions have been associated with extensive nodal involvement, rapid disease progression, and short survival times. Whether trisomy 12, 13q14, and 6q deletions have a prognostic impact awaits further study. The application of these molecular cytogenetic techniques will also contribute to the identification of the pathogenetically relevant genes that are affected by the chromosome aberrations in B-CLL. Received: 2 February 1998 / Accepted: 31 March 1998     

Population structure and admixture in Cerro Largo, Uruguay, based on blood markers and mitochondrial DNA polymorphisms.

Recent studies of the Uruguayan population revealed different amounts of Amerindian and African genetic contributions. Our previous analysis of Afro-Uruguayans from the capital city of the Department of Cerro Largo showed a high proportion of African genes, and the effects of directional mating involving Amerindian women. In this paper, we extended the analysis to a sample of more than 100 individuals representing a random sample of the population of the whole Department. Based on 18 autosomal markers and one X-linked marker, we estimated 82% European, 8% Amerindian, and 10% African contributions to their ancestry, while from seven mitochondrial DNA site-specific polymorphic markers and sequences of hypervariable segment I, we determined 49% European, 30% Amerindian, and 21% African maternal contributions. Directional matings between Amerindian women and European men were detected, but differences involving Africans were not significant. Data about the specific origins of maternal lineages were also provided, and placed in a historical context.     

Long PCR-ribotyping of nontypeable Haemophilus influenzae.

PCR-ribotyping, a new typing method based on long PCR, has been developed for nontypeable Haemophilus influenzae (NTHi). Ribosomal operons of NTHi were amplified by long PCR and were found to be highly polymorphic for internal HaeIII sites. The technique was applied to 49 isolates previously subjected to conventional ribotyping, and the two methods showed a high level of concordance for serial isolates from individual subjects. PCR-ribotyping provides a powerful new typing tool for strain characterization in epidemiological investigations of NTHi.     

Subdivision of Burkholderia pseudomallei ribotypes into multiple types by random amplified polymorphic DNA analysis provides new insights into epidemiology.

Ribotyping has previously been used for epidemiological studies of Burkholderia pseudomallei (previously Pseudomonas pseudomallei). We show here that random amplified polymorphic DNA (RAPD) analysis allows subdivision of strains of the same ribotype. With five different primers, no two epidemiologically unrelated isolates of any single ribotype in this study of 102 isolates from humans, goats, cats, and soil had identical RAPD patterns. Conversely, RAPD analysis showed clonality for isolates from each of two animal outbreaks of melioidosis and from a nontropical focus of animal and human melioidosis spanning 25 years. Some soil isolates were identical to epidemiologically related animal and human isolates as determined by RAPD typing. There was no evidence that the clinical outcome of melioidosis was related to RAPD patterns.