IL-7 stimulates protective immunity in mice against the intracellular pathogen, Toxoplasma gondii

Cytokines, in particular IFN-gamma and IL-12, are important in host protection against infection with Toxoplasma gondii. This parasite is a major cause of congenital infection and morbidity in immunosuppressed persons, especially those with AIDS. IL-7, a monomeric protein produced by bone marrow stromal cells and fetal thymus, is able to induce the proliferation of pro-B cells and CD4+ and CD8+ T cells, and to enhance cytotoxicity of CTL and NK cells. Inbred mice were infected with a lethal dose of T. gondii and given IL-7 twice daily. Mice treated with IL-7 beginning at the time of infection survived, whereas mice either treated after infection or not treated died. Phenotypic analysis of splenocytes identified an expansion of NK (asialo GM1+) cells and CD8+ T cell populations. In vivo depletion of NK (asialo GM1+) and CD8+ T cells showed that cells expressing these phenotypes were important for maintaining protection against the parasite. IFN-gamma depletion resulted in complete reversal of the protective effect of IL-7 administration. In vivo depletion of endogenous IL-7 enhanced susceptibility to infection. Cytokine analysis by semiquantitative reverse-transcriptase PCR showed that IL-7 enhances the IFN-gamma response and furthermore reverses the parasite-mediated down-regulatory response on IL-2. These observations indicate that exogenous administration of human rIL-7 is able to protect mice against acute parasite challenge by stimulating IFN-gamma production and augmenting the CD8+ T cell-mediated CTL response.

IL-7 stimulates protective immunity in mice against the intracellular pathogen, Toxoplasma gondii

Cytokines, in particular IFN-gamma and IL-12, are important in host protection against infection with Toxoplasma gondii. This parasite is a major cause of congenital infection and morbidity in immunosuppressed persons, especially those with AIDS. IL-7, a monomeric protein produced by bone marrow stromal cells and fetal thymus, is able to induce the proliferation of pro-B cells and CD4+ and CD8+ T cells, and to enhance cytotoxicity of CTL and NK cells. Inbred mice were infected with a lethal dose of T. gondii and given IL-7 twice daily. Mice treated with IL-7 beginning at the time of infection survived, whereas mice either treated after infection or not treated died. Phenotypic analysis of splenocytes identified an expansion of NK (asialo GM1+) cells and CD8+ T cell populations. In vivo depletion of NK (asialo GM1+) and CD8+ T cells showed that cells expressing these phenotypes were important for maintaining protection against the parasite. IFN-gamma depletion resulted in complete reversal of the protective effect of IL-7 administration. In vivo depletion of endogenous IL-7 enhanced susceptibility to infection. Cytokine analysis by semiquantitative reverse-transcriptase PCR showed that IL-7 enhances the IFN-gamma response and furthermore reverses the parasite-mediated down-regulatory response on IL-2. These observations indicate that exogenous administration of human rIL-7 is able to protect mice against acute parasite challenge by stimulating IFN-gamma production and augmenting the CD8+ T cell-mediated CTL response.

CAG repeat expansion of Machado-Joseph disease in the Japanese: analysis of the repeat instability for parental transmission, and correlation with disease phenotype

Machado-Joseph disease (MJD) is caused by abnormal expansion of an unstable CAG repeat in a novel gene locating on chromosome 14q32.1. We analysed this CAG repeat polymorphism with 66 Japanese MJD patients. All the patients were selectively associated with abnormal expansion of the CAG repeat. Repeat length of the mutant allele did not overlap that of normal allele and closely correlated with not only age at onset but also with clinical phenotypes. CAG repeat size is apparently related to a wide variety of phenotypic presentations in MJD.

Splicing mutations in the COL4A5 gene in Alport's syndrome: different mRNA expression between leukocytes and fibroblasts

The COL4A5 gene from 40 patients with Alport's syndrome was examined using single-strand conformation substitution at the acceptor site (-2) of intron 50 and a G-to-C substitution at the donor site (+1) of intron 47, respectively. The transcript in peripheral leukocytes from the former had a 10-nucleotide deletion. This shortened transcript was derived from abnormal splicing in a cryptic acceptor site within exon 51. This could be translated into a protein with an alteration of three amino acids followed by premature termination, which eliminated 23 amino acids from the carboxyl end. Gene tracking revealed that the mother and a brother carried the mutant allele. In the latter, the transcript in leukocytes was normal, but that in cultured skin fibroblasts showed skipping of exon 47, the result being that 71 amino acids were absent. Glomerular basement membrane from the patient did not react with the anti-alpha 5(IV) antibody. His maternal grandmother, mother, and a sister, all with abnormal urinalysis, carried the mutant allele. Thus, the appearance of exons of the COL4A5 gene in leukocytes may differ from that in fibroblasts. If kidney mRNA is not available, mRNAs from cultured skin fibroblasts, in addition to leukocytes, can be used for gene analysis in subjects with Alport's syndrome.

Diagnosis of premature rupture of membranes with an improved alpha-fetoprotein monoclonal antibody kit

We developed a new kit for detecting alpha-fetoprotein (AFP) in leaked amniotic fluid (Eur J Obstet Gynecol Reprod Biol 1995;58:67-72). Later, we developed an improved AFP kit utilizing the same AFP monoclonal antibody. We compared this improved AFP test with the nitrazine test for 137 patients. The nitrazine test correctly diagnosed 62.1% of the cases, but the improved AFP kit diagnosed 98.0% for < 37 weeks of gestation (P < 0.001). The nitrazine test showed a specificity of 58.3%, whereas the AFP kit showed a 100% rate for detecting > or = 37 weeks of gestation (P < 0.01). The reaction time with the AFP kit is 90 s. This study has confirmed a high clinical efficacy of the improved AFP test kit as a method of diagnosis of premature rupture of fetal membranes.

[Anesthesia with transesophageal echocardiography for removal of pheochromocytoma]

A 45-year-old female was scheduled for left adrenalectomy because of a pheochromocytoma. Preoperative general condition was well controlled with alpha- and beta-blockers. Anesthesia was induced with thiamylal and vecuronium, and maintained with isoflurane (0.5-3%) and nitrous oxide in oxygen. Blood pressure was controlled with nicardipine and alpha-blocker during the manipulation of the tumor. After removal of the tumor, dopamine and norepinephrine were used. We used transesophageal echocardiography (TEE) to determine the fluid administration rate and doses of catecholamine. We could observe the wall motion and the mass of the heart, and see changes of the left ventricular enddiastolic volume, the cardiac output and the stroke volume. TEE monitoring seems to be very useful during the resection of pheochromocytoma.

Diagnosis of premature rupture of membranes with an improved alpha-fetoprotein monoclonal antibody kit

We developed a new kit for detecting alpha-fetoprotein (AFP) in leaked amniotic fluid (Eur J Obstet Gynecol Reprod Biol 1995;58:67-72). Later, we developed an improved AFP kit utilizing the same AFP monoclonal antibody. We compared this improved AFP test with the nitrazine test for 137 patients. The nitrazine test correctly diagnosed 62.1% of the cases, but the improved AFP kit diagnosed 98.0% for < 37 weeks of gestation (P < 0.001). The nitrazine test showed a specificity of 58.3%, whereas the AFP kit showed a 100% rate for detecting > or = 37 weeks of gestation (P < 0.01). The reaction time with the AFP kit is 90 s. This study has confirmed a high clinical efficacy of the improved AFP test kit as a method of diagnosis of premature rupture of fetal membranes.

[Clinical study on cerebrovascular diseases after renal transplantation]

Between October 1975 and December 1994, 131 renal transplants were performed on our hospital. Eight of these patients had 9 cerebrovascular diseases, which were 2 cerebral hemorrhages, 5 cerebral infarctions, 2 subarachnoid hemorrhages. Five of the 8 patients whose graft functions were bad died. We studied the relationship of the incidence of these complications to some factors as follows; 1) blood pressure, 2) hypercholestemia, 3) duration of hemodialysis, and 4) graft function. The cerebrovascular diseases after renal transplantation were related to the hypertension after renal transplantation and no correlation with the other factors could be found. Therefore, we think that the control of the hypertension after renal transplantation is the most important for the cerebrovascular diseases and the patient's prognosis.

Attenuation of adrenomedullin-induced renal vasodilatation by NG-nitro L-arginine but not glibenclamide

1. The present study was conducted in order to elucidate the in vivo contribution of nitric oxide (NO) and the glibenclamide-sensitive potassium channel in the renal action of adrenomedullin in anaesthetized dogs. 2. Intrarenal arterial infusion of adrenomedullin (20 ng kg-1 min-1) elicited a pronounced increase in renal blood flow with no changes in systemic blood pressure. The renal vasodilator action of adrenomedullin was markedly attenuated by pretreatment with NG-nitro L-arginine (L-NOARG), but this was reversed by continuous infusion of L-arginine. 3. Pretreatment with glibenclamide almost completely blocked the renal vasodilatation induced by lemakalim, but had no effect on the renal vasodilator and diuretic action of adrenomedullin. 4. Intrarenal arterial infusion of adrenomedullin induced diuresis and natriuresis. Diuretic and natriuretic action of adrenomedullin was also attenuated by L-NOARG. L-Arginine partly reversed the effect of L-NOARG and adrenomedullin-induced diuresis and natriuresis. 5. These data indicate that the in vivo renal vasodilator action of adrenomedullin is mediated by the release of NO. The glibenclamide-sensitive potassium channel is not involved in the renal action of adrenomedullin, at least, not in anaesthetized dogs. Since the inhibition of L-NOARG of adrenomedullin-induced diuresis occurred concomitantly with the attenuation of the renal vasodilator action of adrenomedullin, direct involvement of NO in adrenomedullin-induced diuresis remains to be established.

Oxytocin-producing and vasopressin-producing eosinophils in the mouse spleen: immunohistochemical, immuno-electron-microscopic and in situ hybridization studies

Oxytocin-like and vasopressin-like immunoreactive cells, and the cells expressing mRNAs for these peptides in the spleen of the C57BL/6 mouse were studied by immunohistochemistry, immuno-electron microscopy and in situ hybridization. Immunoreactive cells were distributed mainly in the splenic cord and marginal zone, whereas there were few in the lymphocyte-packed periarteriolar-lymphoid sheath, lymphoid follicle and germinal center. More numerous vasopressin-positive cells were seen in the splenic cord. The colocalization of oxytocin-like and vasopressin-like immunoreactivity in the same cells was identified by the investigation of mirror sections. By the pre-embedding immuno-electron-microscopic method using antisera against oxytocin and vasopressin, immunopositive reaction products were localized in the matrix around the specific granules, small clear vesicles and mitochondrial membrane of the eosinophils. No immunoreactivity to these peptides was found within the specific granules of the eosinophils. In situ hybridization with synthetic oligonucleotide probes labeled with 32P revealed the presence of mRNAs for oxytocin and vasopressin in the cells of the spleen, the distribution of the mRNAs for these peptides being the same as that of immunopositive cells. These observations suggest that eosinophils synthesize both oxytocin and vasopressin and store them in the matrix. Possible differences in the mechanism of synthesis and storage of these peptides between peripheral eosinophils and hypothalamic neurons are discussed.

Expression of a cell adhesion molecule, neuropilin, in the developing chick nervous system

Neuropilin (previously known as the A5 protein) is a membrane protein identified in Xenopus and is presumed to be involved in the target recognition of the optic nerve fibers. We have isolated cDNAs encoding the chick homologue of neuropilin, using the Xenopus neuropilin cDNA as a hybridization probe. The predicted amino acid sequence of chick neuropilin is 75% identical to that of the Xenopus homologue. A cell aggregation assay showed that fibroblasts transfected with the chick neuropilin cDNA acquired cell adhesiveness. This adhesion is mediated by a heterophilic interaction between neuropilin and protease-sensitive molecules on fibroblasts. The expression of chick neuropilin is restricted to certain neuronal circuits and is dynamically regulated during development, as is the Xenopus homologue. However, their expression patterns differed significantly in the visual systems between the two species: In the chick optic tectum, the localization of neuropilin is confined to layers d and e of SGFS, two of the six layers receiving the retinal input; the chick optic nerve fibers do not express neuropilin; in the chick retina, amacrine cells transiently express neuropilin. Cultured neurons of the dorsal root ganglia express chick neuropilin on their neurites including growth cones. These results suggests that neuropilin functions as a cell adhesion molecule during the formation of certain neuronal circuits in vivo.

[Renal transplant calculi in a renal allograft treated with extracorporeal shock wave lithotripsy in a patient with persistent hyperparathyroidism: a case report]

Between 1984 and 1991, six of 105 renal transplant recipients at our institution formed urinary tract calculi after transplantation (5.7%). In these 6 patients, one case of nephrolithiasis in a transplanted kidney was treated with extracorporeal shock wave lithotripsy (ESWL). A 37-year-old woman underwent cadaveric renal transplantation twenty months before, and her renal function remained stable. However calculi in the transplanted kidney and bladder were formed and ESWL was used for the treatment of the renal calculus in the transplanted kidney. She was discharged from the hospital two weeks postoperatively while passing small gravel in the urine after successful fragmentation of the calculus without any major complications. As follow-up KUB film two weeks later demonstrated that all stone fragments had been passed, but she was treated again by ESWL four months later because IVP films four weeks later revealed recurrent calculi in the transplanted kidney. The stones were fragmented successfully and spontaneously passed with voiding. Moreover we performed total parathyroidectomy with autotransplantation for persistent hyperparathyroidism, with subsequent good clinical results.

Establishment of a new human cell line, LI90, exhibiting characteristics of hepatic Ito (fat-storing) cells

BACKGROUND

Thus far, human hepatic Ito (fat-storing) cell lines have not been established. Therefore, functional characteristics of Ito cells have not been fully investigated.

EXPERIMENTAL DESIGN

We established a new cell line, LI90, that exhibited characteristics compatible with those of Ito cells from a human hepatic mesenchymal tumor. LI90 cells were examined with phase-contrast microscopy, immunohistochemistry, and cytogenetics, and their vitamin A-storing activity was analyzed. To obtain a marker specific for Ito cells for immunohistochemical analyses, we raised mAb against LI90 cells and clarified the molecular nature of the Ag recognized with the new Ab using an expression cloning approach.

RESULTS

LI90 cells showed polygonal shape and had well developed alpha-smooth muscle actin filaments in their cytoplasm. In an overconfluent culture condition, LI90 cells aggregated to form a typical hills-and-valleys structure, LI90 cells produced various connective tissue components, such as collagen types I, III, IV, V, and VI, laminin, and fibronectin. In culture media containing vitamin A, LI90 cells formed many fat droplets in their cytoplasm, and fluorescence characteristic of vitamin A was observed in the droplets. By immunizing mice with LI90 cells, three separate mAb specifically reacting with Ito cells in human liver sections were established, and the Ag recognized with all three Ab were identified as extracellular matrix tenascin.

CONCLUSIONS

The above-described morphologic and functional characteristics, including vitamin A-storage and biosynthesis of tenascin, are compatible with those of Ito cells. Therefore, LI90 cells will be useful for in vitro studies of functions of human Ito cells.

[Examination on aspirin-induced asthma and hypersensitivity to steroids--a questionnaire to 850 asthma on hypersensitivity to non-steroidal anti-inflammatory drugs and hypersensitivity to steroids]

We surveyed 850 patients with bronchial asthma and investigated such clinical features as the frequency of aspirin-induced asthma and hypersensitivity to steroids in the 457 available answers. We divided them into two groups, one was ASN: the asthmatics who had history of hypersensitivity to non-steroidal anti-inflammatory drugs, another was non-ASN: the asthmatics who had no history of hypersensitivity to non-steroidal anti-inflammatory drugs, and compared the two groups. The survey showed that the frequency of ASN was 12.0%. Its frequency rose with the severity of asthma to a level of 29.0% in severe cases. In ASN it was more frequent rates of female, infectious type, severe cases, and ASN had more frequent histories of oral use of steroids, use of ambulance, treatment in emergency rooms, and hospitalization than non-ASN. The serum IgE level was lower in ASN. The patients were 6 in ASN, none in non-ASN who had histories of hypersensitivity to steroids. They were 1.3% in all patients. 5 of 6 had past asthma attack progressived severely by rapid injection of succinate ester steroids and 2 of 6 had past by rapid injection of phosphoric acid ester steroids. In conclusion it was considered that we had to avoid rapid injection of steroids to aspirin-induced asthma and severe cases who were doubtful of aspirin-induced asthma in case of treatment of asthma attack.

[Tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in transplanted kidneys]

We have studied the involvement of fibrinolysis in acute rejection after kidney transplantation by analyzing changes in urinary levels of substances such as FDP, D-dimer, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI). Fibrinolytic activity was found to be low (that is, PAI is dominant) during acute rejection, and it was elevated (that is, PA became dominant) as acute rejection subsided. It appears that the dominance of PA leads to an increase in the products of fibrinolysis and an elevation in the D-dimer/FDP ratio, resulting in disappearance of the acute rejection. Based on these findings, we thought it necessary to administer t-PA to kidney recipients so that PA becomes dominant earlier and the acute rejection can be reduced. It is necessary for us to directly study the phenomena within the kidneys. Therefore, we recently conducted a histochemical study of the distribution of t-PA, Urokinase type PA (u-PA) and PAI in transplanted kidneys. Transplanted kidney, which functioned well or showed signs of acute or chronic rejection, were biopsied. These renal samples as well as control samples (biopsied from normal nongrafted kidney) were examined as to distribution of t-PA, u-PA and PAI by the indirect enzyme complement method. In conclusion, t-PA, u-PA and PAI were detected in the glomeruli, arterioles, tubule and interstices of the control kidneys, well functioning grafts, acutely rejected grafts chronically rejected grafts. All samples showed intense chromatic responses in the arterioles and part of the tubules. On the whole, the chromatic response tended to be more intense in the acute rejection group than in the other group.

Elevation of interleukin-6 in inflammatory bowel disease is macrophage- and epithelial cell-dependent

Local interleukin-6 (IL-6) activity was studied using colonic mucosal tissues in inflammatory bowel disease (IBD) and inflammatory control patients. Active IBD specimens exhibited significantly higher IL-6 activity than control specimens in both cultures of isolated lamina propria mononuclear cells (LPMC) and mucosal tissues with an increased number of IL-6-producing cells. However, the activity in inactive IBD or inflammatory controls did not differ from controls. Northern blot analysis demonstrated IL-6 messenger RNA in LPMC and colonic epithelial cells isolated from active IBD specimens but not in control cells. Furthermore, immunofluorescent microscopic study of active IBD specimens showed more conspicuous staining of IL-6 in infiltrating LPMC (mostly CD68+ cells) and colonic epithelial cells. These results suggest that elevation of local IL-6 activity may be a characteristic feature of active IBD and both macrophages and colonic epithelial cells are the major cell types responsible for this phenomenon.

Ultrastructural, immunocytochemical and stereological investigation of hepatocytes in a patient with the mutation of the ornithine transcarbamylase gene

We studied a male newborn suffering from deficiency of ornithine transcarbamylase (OTC) that is due to a G-to-A substitution in codon 269 of the OTC gene. This study intends to define the cell biological mechanisms in this naturally occurring OTC mutation which may explain the mild clinical course in spite of the very low residual enzyme activity. Using immunogold labeling of thawed thin frozen sections of liver from this patient and a control liver, we analyzed the quantitative distribution of several mitochondrial proteins in the cytosol and the mitochondria of hepatocytes. In addition, the absolute volumes and surface densities of mitochondria and peroxisomes were determined. Our results show that the absolute volume of mitochondria in the patient's hepatocytes was increased to 141% (P < 0.001) without any change in the surface density indicating an increased number of mitochondria. In the patient's hepatocytes the peroxisomes were increased in size but not in number. The concentration of OTC was elevated in the cytosol (P < 0.001) and to a lesser extent in mitochondria (P < 0.01) of the patient's hepatocytes thus indicating a doubling of OTC relative to control liver cells. The quantity of OTC in mitochondria was 63% higher in diseased liver cells. By conventional thin section electron microscopy, mitochondria-like structures with poorly defined cristae and an electron-dense matrix were observed in the cytoplasm of the diseased hepatocytes. By immunoelectron microscopy, they contained the cytochrome c oxidase II subunit as well as DNA but lacked OTC, carbamylphosphate synthetase, F1-ATPase beta subunit and catalase. Thus it appears that these structures represent defective and probably degenerating mitochondria. Our data indicate that the reduced enzyme activity of the mutant OTC is partly compensated by an increased amount of enzyme molecules in the cytosol as well as mitochondria combined with an increase in the biogenesis of mitochondria.