Lactic dehydrogenase virus (LDV) impairs the antigen-presenting capacity of macrophages yet fails to affect their phagocytic activity

The effect of acute infection of mice with lactic dehydrogenase virus (LDV) on two major functions of peritoneal macrophages was tested. Using a macrophage-dependent T cell proliferative assay to test the antigen-presenting capacity of LDV-infected macrophages we found that LDV impairs the capacity of antigen-presenting cells to trigger memory T lymphocytes. Endocytosis of antigen by LDV-infected macrophages was similar to that of uninfected cells. In addition, the proportion of intracellular antigen versus membrane-bound antigen in LDV-infected cells were similar to that observed in uninfected mice. It appears therefore, that the impaired immunogenic effect of LDV-infected macrophages results from reduced immunogenicity of the membrane-bound antigen.Testing the phagocytic activity of peritoneal macrophages we found that the uptake of radiolabeled antibody-coated sheep erythrocytes or bacteria (E. coli) by infected cells was similar to that by uninfected macrophages. In addition, LDV failed to affect the ability of peritoneal macrophages in a nitroblue tetrazolium reduction reaction which serves as an alternative parameter for measuring phagocytic activity. Our results support the assumption that LDV, which probably propagates in the cells of the reticuloendothelial system, impairs some of the immunogenic functions of macrophages and thereby affects macrophage-dependent immune responses.     

Characterization of the antisecretory action of prostaglandin D2 in the rat colon

Previous studies have shown that prostaglandin D₂ (PGD₂) inhibits neuronally mediated secretion in the rat colon. This antisecretory action of PGD₂ was further characterized by the use of a prostaglandin D receptor blocker. Prostaglandin D₂ inhibited the neuronally mediated short-circuit current evoked by prostaglandin I₂, which represents Cl^- secretion. The concentration-response curve for the inhibition by PGD₂ was shifted to the right in the presence of the prostaglandin D receptor blocker, AH 6809. AH 6809 had no effect on the short-circuit current response induced by prostaglandin E₂ or iloprost, a stable prostaglandin I₂ analogue, suggesting an interaction of the blocker with receptors specific for PGD₂. A direct interaction of PGD₂ with enteric neurones was studied by determining its effect on acetylcholine release from enteric neurones preloaded with [³H]choline. Prostaglandin D₂ suppressed ³H release induced by electric field stimulation. It had, however, no effect on the release induced by depolarization with potassium. The results suggest that the inhibitory action of PGD₂ on enteric cholinergic neurones is mediated by prostaglandin D receptors.     

Rapid identification of female carriers of DMD/BMD by quantitative real-time PCR

Recently developed PCR systems offer online-monitoring of amplification and allow simple and reliable DNA quantification. We have used the LightCycler system to develop a simple and rapid method for direct identification of female carriers of deletions and duplications in the dystrophin gene. The challenge resides in the ability to identify the presence of a deleted or duplicated allele over the background contributed by the normal allele. Quantification is based on the determination of the ratio between potentially deleted/duplicated dystrophin exons and non-deleted/-duplicated reference exons using the unspecific dsDNA-dye SYBRgreen I. In a retrospective study, we evaluated our method in female relatives of DMD/BMD patients with known carrier status by comparative analysis of deleted or duplicated versus non-deleted/-duplicated exons. Carrier status was accurately attributed in 100% of cases, the mean ratios being 0.52+/-0.12 for deletion carriers (expected value: 0.5) and 1.56+/-0.18 for duplication carriers (expected value: 1.5) vs. 1.022+/-0.17 for non-carriers (expected value: 1.0). The method proved to be simple, rapid, reliable, and cost-effective. It may be used for direct determination of deletions/duplications in potential DMD/BMD carriers and may easily be adapted for other genetic conditions involving deletions and duplications.     

Iloprost对内皮细胞抗血栓功能的影响

以体外培养的猪主动脉内皮细胞（ＥＣ）为模型研究Ｉｌｏｐｏｓｔ对ＥＣ抗血栓功能的影响。用放免法、发色底物法测定培养液中６－酮－ＰＧＦ１α（６－ｋｅｔｏ－ＰＧＦ１α），血栓素Ｂ２（ＴＸＢ２）含量，纤溶酶原激活物（ＰＡ），纤溶酶原激活物抑制物（ＰＡＩ）活性及ＥＣ环磷酸腺苷（ｃＡＭＰ）含量。结果表明：Ｉｌｏｐｒｏｓｔ中以使ＥＣ生成６－ｋｅｔｏ－ＰＧＦ１α，ｃＡＭＰ含量显著增多，ＴＸＢ２含量显著减少，并使Ｐ     

Elongated peptides,not the predicted nonapeptide stimulate a major histocompatibility complex class I-restricted cytotoxic T lymphocyte clone with specificity for a bacterial heat shock protein

The peptides recognized by an H-2D^b-restricted CD8 cytotoxic T lymphocyte (CTL) clone which is specific for the 60-kDa mycobacterial heat shock protein (hsp) and cross-reacts with stressed host cells were characterized. None of the nonapeptides from hsp60 conforming to the H-2D^b binding motif were able to sensitize target cells for lysis by this CTL clone. Sequence analysis of the stimulatory fraction from a trypsin digest of hsp60, together with synthetic peptide studies, defined a cluster of overlapping epitopes. Carboxy-terminal extension by at least one amino acid of the nonamer predicted to bind best to H-2D^b was essential for CTL recognition. Two such elongated peptides, a 10-mer and a 12-mer stimulated the clone at similarly low concentrations in the 100 pM range. We assume that these two peptides comply best with the natural epitope. In contrast, the 11-mer was inactive. The stimulatory 10-mer bound to H-2D^b with an efficacy similar to that of the nonapeptide corresponding to the H-2D^b motif, as revealed by peptide induced major histocompatibility complex (MHC) surface expression on RMA-S cells and competitive blocking of epitope recognition by the nonamer. Binding of these carboxy-terminally extended peptides to the MHC groove can be explained by anchoring through the amino acid residue Asn in position 5 of the peptide and by intrusion of the hydrophobic carboxy-terminal Ala (10-mer) or Leu (12-mer), but not Gly (11-mer), into the hydrophobic pocket of the H-2D^b cleft. Because the carboxy-terminal part is thus larger than predicted this region of the peptide may arch up from the binding groove. We assume that recognition of steric components of the MHC/peptide complex broaden the range of epitope specificity for a single T cell receptor. This flexibility not only promotes recognition of several overlapping peptides from a single antigen, but may also increase the chance of cross-reaction with similar peptides from unrelated proteins, including autoantigens. Consistent with this latter assumption, the T cell clone cross-recognizes mycobacterial hsp60 and stressed host cells.     

Two Cases of Peritoneal Serous Papillary Adenocarcinoma

Two cases of peritoneal papillary carcinoma are reported. The patient in the first case was a 71-year-old woman with symptoms of obstructive ileus. Laparotomy revealed a tumor in the omentum involving the transverse colon, and several small tumors in the peritoneum and pelvic wall. However, no primary site of the tumor was seen in the ovary, pancreas, or gastrointestinal tract. The patient in the second case was a 44-year-old woman with carcinomatous peritonitis. Postmortem examination revealed multiple tumors in the peritoneum, omentum, and pelvic wall. Tumors were also found in the cortex with mild invasion of the underlying parenchyma of the bilateral ovaries, although these lesions were thought to be metastatic. The histologic features of the tumor in both cases were those of tubulopapillary adenocarcinoma containing scattered psammoma bodies. The cells were positive with the PAS D technique, but negative with alcian blue staining. In both cases, the serum levels of CA-125 were considerably elevated, and the tumor cells showed positivity for CA-125, S 100 protein, cytokeratin and EMA by im-munohistochemistry. The present cases were most likely peritoneal serous papillary adenocarcinoma derived from extraovarian peritoneal mesothelium with miillerian potential, being different from the usual type of diffuse malignant mesothelioma. Acta Pathol Jpn 41: 642-646, 1991.     

Charcot-Marie-Tooth disease: molecular characterization of patients from Central and Southern Italy

The syndrome of peroneal muscular atrophy, or Charcot-Marie-Tooth (CMT), disease represents the most common inherited peripheral neuropathy, with a prevalence of about 1 per 2500. The disease is usually transmitted in an autosomal dominant fashion, although it can display all the mendelian patterns of inheritance. The chromosome 17-linked form (CMT1a) appears to be the most common form of the disease in all the ethnic groups studied so far, Italians included, and is due to a tandem duplication in 17p11.2. In order to study the distribution of CMT types and to establish a genotype-phenotype correlation in patients from Central and Southern Italy, we collected 19 CMT pedigrees diagnosed in the years 1992–1993. Simple tandem repeats (STR) polymorphism analysis with the marker RM11-GT and Southern blotting with the probes pVAW409R3 and pVAW412 were performed, demonstrating a high prevalence (about 60%) or 17p duplication in the families studied. No clinical or electrophysiological differences were noted between CMT1 patients with or without 17p duplication, respectively. Two families affected by CMT2 showed no evidence of rearrangement at the D17S122 locus. These data are consistent with the hypothesis of a different molecular basis for CMT2.     

Progressive dilated cardiomyopathy in a patient with longstanding and complete prednisone-induced hematological remission of idiopathic hypereosinophilic syndrome

Summary A female patient is described in whom the diagnosis of idiopathic hypereosinophilic syndrome (HES) with heart disease and peripheral neuropathy was made at the age of 32 years. Although prednisone induced a prompt and longstanding complete hematological remission, progressive and eventually intractable heart failure developed, and the patient died 6 years later. Endomyocardial biopsy at diagnosis showed infiltration with intact and disintegrated eosinophils and Charcot-Leyden crystals. Echocardiographic follow-up (including Doppler-Echocardiography) revealed mitral regurgitation with thickening and impaired motility of the posterior mitral leaflet, as well as progressive dilated cardiomyopathy. At autopsy, a diffuse interstitial fibrosis with patchy prominence in an eccentric hypertrophic and highly dilated heart was found. There were no significant endocardial thickening and no mural thrombi. In contrast to the findings of the initial endomyocardial biopsy, autopsy revealed no eosinophilic infiltrate.In this case, eosinophil-induced heart disease manifested as dilated cardiomyopathy, without endocardial fibrosis as originally described by Löffler. We speculate, that eosinophils have been deposited predominantly in the myocard at an early stage of disease, and — activated locally — secreted their granule proteins producing an initial damage to capillary endothelial cells and myocytes. After prednisone-induced clearance of eosinophils from blood and tissues, progressive, self-perpetuating interstitial fibrosis of the myocard and loss of myocytes eventually resulted in end-stage dilated cardiomyopathy.Abkürzungsverzeichnis HES idiopathic hypereosinophilic syndrome - UBBC unsaturated vitamin B₁₂ binding capacity - ECP eosinophil cationic protein - MBC major basic protein - EDD end-diastolic diameter of the left ventricle - LA left atrium diameter - LVEDP left ventricular end-diastolic pressure - NIH National Institutes of Health     

The postnatal development of thalamocortical projections from the pulvinar in the cat

Summary The postnatal development of thalamocortical projections from the pulvinar to an association cortex of the cat, the crown of the middle suprasylvian gyrus, was studied by using both HRP and evoked field potentials. From birth onward, the pulvinar sends dense fibres to this cortical area, but the cortical laminar distribution of the afferents was found to change markedly with aging. An orthograde HRP study showed that at birth and up to 2 weeks of age, the terminals are distributed mainly in layer I, whereas in adult cats and kittens older than 1 month, the terminals are found largely in and around layer IV and only sparsely in layer I. After HRP injections exclusively into layer I of the crown, numerous thalamic neurones were retrogradely labelled in both the ventroanterior-ventrolateral complex (VA-VL) and the pulvinar in 5-day-old kittens, but in the VAVL alone in 2-month-old kittens. In agreement with these anatomical findings, stimulation of the pulvinar elicited a surface-negative, depth-positive potential in 1-week-old kittens, indicating the existence of a large current sink in layer I; however, it induced a surface-positive, depth-negative potential in 1month-old kittens, reflecting the presence of a strong current sink in the deep cortical layers.     

Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I.