A diabetogenic gene (ODB-1) assigned to the X-chromosome in OLETF rats

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat develops hyperglycemia, hyperinsulinemia and mild obesity, features that closely resemble those in human non-insulin-dependent diabetes mellitus (NIDDM). Here, we report a gene involved in the development of diabetes in OLETF rats. Segregation studies using OLETF and an unrelated strain, F344 showed that no diabetes was observed in F1 progeny and less than 12.5% of the F2 progeny developed diabetes, suggesting that multiple recessive genes are involved in the disease. Interestingly, diabetes was observed in approximately 40% of (OLETF female x LETO male) F1 male rats, whereas less than 4% of males were diabetic in the reverse F1 mating. This suggested that the LETO rat which has been established from the same original colony as the OLETF rat shares some, but not all, diabetogenic genes with the OLETF, and that one of the responsible genes locates on the X-chromosome. Linkage study using (OLETF female x F344 male)F2 progeny has confirmed that one of the diabetogenic loci in the OLETF rats locates on the X-chromosome 14 cM distant from the AR gene (LOD = 2.598) and has been designated as ODB-1.

Primary and reversible injury of H(+)-ATPase in warm ischemia and reperfusion of rat liver in relation to intramitochondrial adenine nucleotide

The injury and recovery processes of complex reactions of liver mitochondrial ATP synthesis during warm ischemia and after reflow were studied separately in terms of the changes in oxidation (electron transfer system) and phosphorylation (H(+)-ATPase). Oxidative activity decreased significantly from the control value of 40 +/- 0.9 (mean +/- SEM, n = 5) to 31.5 +/- 1.13 (nanoatoms oxygen consumed/min/mg protein) after 40 min of warm ischemia, while phosphorylative activity decreased significantly from the control value of 1.06 +/- 0.12 to 0.42 +/- 0.03 (mumole ATP hydrolyzed/min/mg protein) after 20 min of warm ischemia. During 120 min of reflow after 20 min of warm ischemia, the decreased phosphorylation activity recovered to 0.52 +/- 0.01 concomitant with a recovery of intramitochondrial total adenine nucleotide and an increase in the ATP/ADP ratio, while oxidative activity decreased further to 23.9 +/- 0.81. These results indicate that H(+)-ATPase is more vulnerable to warm ischemia than the electron transfer system, but that it is restored concomitant with the recovery of intramitochondrial adenine nucleotide content.

Effect of galactosamine-induced hepatitis on the aerobic and anaerobic metabolism of the rat exposed to high-altitude hypoxia

Galactosamine-induced hepatitis caused a marked increase in plasma lactate and pyruvate, but completely abolished the increase in ketone bodies in the rat exposed to an 8000 m simulated altitude. Plasma free fatty acid as the precursor of ketone bodies was higher in the galactosamine-treated rats during and after an exposure to 8000 m altitude. Treatment of the rat with galactosamine markedly reduced activities of citrate synthase, fumarase, glutamate dehydrogenase and fructose 1,6-bisphosphatase, but increased hexokinase and glucose 6-phosphate dehydrogenase in the liver. The effect of galactosamine-induced hepatitis on the energy metabolism can be explained by a reduction of mitochondrial oxidative enzymes and gluconeogenesis, and involves a shift of the aerobic metabolism to anaerobic glycolysis at high altitude.

Evaluation of water molecules in the cold-preserved rat liver by proton magnetic resonance imaging

Hypothermically preserved rat livers were studied with proton magnetic resonance imaging (1H-MRI) under proton density-, spin-lattice relaxation time-, spin-spin relaxation time- and diffusion-weighted (P-W, T1-W, T2-W and D-W) conditions. Relative signal intensities (RSI) of the liver to distilled water in terms of P-W, T1-W, T2-W and D-W increased time-dependently during 12 h hypothermic (4 degrees C) preservation with saline, while these parameters did not increase during preservation with University of Wisconsin (UW) solution. One-hour Wiggers' hypotensive treatment before the harvesting increased the RSIs of P-W, T2-W and D-W, and the subsequent 12-hour preservation with UW solution did not improve the increased RSIs. These results suggest that 1H-MRI has potential application in evaluating the biophysical changes of water molecules in the liver graft, which were measured by placing the harvested liver in a plastic bag under a magnetic field at a low temperature.

Pemphigus IgG, but not bullous pemphigoid IgG, causes a transient increase in intracellular calcium and inositol 1,4,5-triphosphate in DJM-1 cells, a squamous cell carcinoma line

It is still unclear what kinds of mechanisms are involved in blister formation after antibodies bind to the antigens in pemphigus and bullous pemphigoid. The effects of IgGs from pemphigus vulgaris, pemphigus foliaceus, and bullous pemphigoid sera on intracellular calcium concentration ([Ca++]i) and inositol 1,4,5-trisphosphate were examined in a human squamous cell carcinoma cell line (DJM-1 cells) and in cultured human keratinocytes to clarify whether signal transduction via calcium is involved. IgGs were purified with protein A affinity column from the sera of five pemphigus vulgaris patients, three pemphigus foliaceus patients, eight bullous pemphigoid patients, and 14 normal volunteers. Keratinocytes were cultured in Eagle's minimum essential medium containing 1.8 mM Ca++ and loaded with fura-2/AM, followed by addition of the IgGs. Subsequently, [Ca++]i was determined by measuring the fluorescence ratio (F340/F360) with videomicroscopy. Pemphigus IgGs (seven of eight cases) induced a rapid and transient increase in [Ca++]i in both the cells, whereas a [Ca++]i increase was caused by very few IgGs from bullous pemphigoid (one of eight cases) and normal sera (two of 14 cases). The pemphigus IgG-induced transient [Ca++]i increase was not affected by chelating extracellular Ca++ with ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetracetic acid. In addition, monoclonal antibodies acid. In addition, monoclonal antibodies against 180-kD and 230-kD antigens did not exert this change. Pemphigus IgGs that caused a [Ca++]i increase induced rapid and transient production of inositol 1,4,5-trisphosphate, peaking at 20 seconds. These findings suggest that IgG from pemphigus induces Ca++ mobilization by inositol 1,4,5-trisphosphate from internal stores, and that mechanisms of antibody-transmitted signaling in pemphigus may differ from those in bullous pemphigoid.

Maintenance of high virus load even after seroconversion in newborn cats acutely infected with feline immunodeficiency virus

The viral loads in adult and newborn cats have been compared following injection with feline CD4+ FeL-039 line cells acutely infected with feline immunodeficiency virus (FIV). The level of virus genome in peripheral blood mononuclear cells (PBMC) increased progressively despite seroconversion in the newborn cats, whereas the virus genome was apparently cleared after seroconversion in the adult cats. Immunohistochemical staining of thymus of the FIV-infected newborn cats showed clusters of viral antigen-positive cells. These results indicate that FIV infection of the newborn cat results in higher virus loads than infection of the adult cat. We discuss these findings in relation to FIV as a model system for studies of the infection of neonates with an immunosuppressive retrovirus.

Thioredoxin h is one of the major proteins in rice phloem sap

Sieve tubes play important roles in the transfer of nutrients as well as signals. Hundreds of proteins were found in pure phloem sap collected from rice (Oryza sativa L. cv. Kantou) plants through the cut ends of insect stylets. These proteins may be involved in nutrient transfer and signal transduction. To characterize the nature of these proteins, the partial amino-acid sequence of a 13-kDa protein, named RPP13-1, that was abundant in the pure phleom sap was determined. A cDNA clone of 687 bp, containing an open reading frame of 122 amino acids, was isolated using corresponding oligonucleotides as a probe. The deduced amino-acid sequence was very similar to that of the ubiquitous thiol redox protein, thioredoxin. The consensus sequences of thioredoxins are highly conserved. No putative signal peptide was identified. Antiserum against wheat thioredoxin h cross-reacted with RPP13-1 in the phloem sap of rice plants. RPP13-1 produced in Escherichia coli was reactive to antiserum against wheat thioredoxin h. Both E. coli-produced RPP13-1 and the phloem sap proteins catalyzed the reduction of the disulfide bonds of insulin in the presence of dithiothreitol. These results indicate that an active thioredoxin is a major protein translocating in rice sieve tubes.

Postnatal development of locomotor movements in normal and para-chlorophenylalanine-treated newborn rats

The contribution of the serotonergic system to postnatal development of locomotor movements in newborn Sprague-Dawley rats was studied from PND 1 to PND 15. To deplete serotonin (5-HT), p-chlorophenylalanine (PCPA) (200 mg/kg) was intraperitoneally administered at PND 1, 4, 7, 10 and 13, and the results obtained from PCPA-treated pups (n = 20) and control pups (n = 20) were compared. Locomotor movements of the pups on the surface of a digitizer table were measured by attaching a miniature coil to the abdomen of the pups. Video-recordings were made to study the locomotor movements. From PND 1 to PND 5, no significant difference in body weights and locomotor movements was observed across control and PCPA-treated pups. After PND 6, the development of PCPA-treated pups was slightly retarded although both groups of pups opened their eyes at PND 14. Throughout PND 6 to PND 15, the total distance and mean velocity of locomotor movements were significantly lower in PCPA-treated pups than in the control pups. In addition, forelimb and hindlimb movements were not well coordinated in the former. These results suggest that retardation of locomotor movements in the PCPA-treated pups is due to a possible failure in the postnatal development of 5-HT and other neural mechanisms related to postural and locomotor control, and not due to that of general development of the pups themselves.

Effects of fluvoxamine on the protein phosphorylation system associated with rat neuronal microtubules

We have studied the phosphorylation system associated with the rat cerebrocortical microtubule fraction after short- and long-term administration (15 mg/kg) of fluvoxamine, a selective serotonin reuptake inhibitor with antidepressant activity. Fluvoxamine administered for 5 days significantly enhanced the 32P incorporation stimulated by cAMP into MAP2, while it failed to produce this effect after 12 and 21 days. Moreover, in the same periods of treatment no changes were observed in basal phosphorylation and in the pattern of microtubule proteins. In conclusion, our results suggest that changes in the protein phosphorylation system associated with the microtubule fraction could represent an early neurochemical modification involved in the action of fluvoxamine.

Mapping of rat bilirubin UDP-glucuronosyl-transferase gene (Ugt1a1) to chromosome region 9q35-->q36

Bilirubin and phenol UDP-glucuronosyltransferases (UGTs) are located on the same chromosome and comprise the UGT1 gene complex. A 1,763-bp cDNA probe (UGT1*0) specific for rat liver bilirubin UGT was used to localize the UGT1 complex locus (Ugt1a1) to chromosome region 9q35-->q36 by fluorescence in situ hybridization. This assignment is the first report on the location of a gene of the rat UGT1 complex using high-resolution banded metaphase chromosomes.

The risk of cancer in rheumatoid patients in Japan

In order to clarify the risk of cancer development in patients with rheumatoid arthritis (RA), the incidence of malignant tumors during a follow-up period was investigated in RA patients at the Center for Adult Diseases, Osaka, Japan. Six hundred and fifty-five eligible rheumatoid patients (131 males, 524 females) who were admitted to our institute between 1980 and 1989 were matched against the files of the Osaka Cancer Registry. Among them, a total of 26 patients (5 males, 21 females) were noted to have developed some kinds of cancer. The female RA patients demonstrated a significantly higher incidence of all cancers than the general population, with an observed/expected (O/E) ratio of 1.71 (95% confidence interval = 1.06-2.62). Cancer of the buccal cavity/pharynx and thyroid cancer also showed a higher incidence in female RA patients, with O/E ratios of 12.93 and 2.74, respectively.

Diffusion weighting by the trace of the diffusion tensor within a single scan

The anisotropy of the water diffusion tensor inside brain causes contrast in diffusion images, which depends on the relative orientation of the diffusion gradients and the subject. Because the trace of a tensor is invariant upon rotation, measurement of this trace can reduce the orientation effect. A family of imaging pulse sequences is presented in which the signal intensity is weighted by the trace of the diffusion tensor in a single scan. The methods are demonstrated for chicken gizzard in several orientations with respect to the gradient frame of reference, and for ischemic injury in cat brain after middle cerebral artery occlusion. The sensitivity of the techniques to the presence of background gradients is measured and discussed in detail. As a result, pulse sequences are suggested that provide reliable diffusion constants in both homogeneous and inhomogeneous magnetic fields. The efficiency of the techniques for clinical application is also evaluated.

Smoldering gamma delta T-cell granular lymphocytic leukemia associated with pure red cell aplasia

We present a case of granular lymphocytic leukemia (GLL) associated with pure red cell aplasia (PRCA). Twenty-seven percent of the peripheral blood mononuclear cells (PBMC) were positive for TCR delta 1, but not for delta TCS1 (V delta 2), and a rearrangement of the TCR chain (J delta 1) gene was detected. The PBMC and serum from the patient slightly suppressed CFU-E but not BFU-E colony formation in vitro. These findings suggest that monoclonal proliferation of TCR gamma delta-positive granular lymphocytes (GL) can be associated with PRCA even in a patient having a small proportion of leukemia GL, which we propose to designate as 'smoldering GLL'.

Changes in the distribution of the control of the mitochondrial oxidative phosphorylation in regenerating rabbit liver

Applying the metabolic control theory, inhibitor titration studies were carried out on Complex I, III, IV, ATP synthase, ATP/ADP carrier and P(i) carrier of mitochondrial oxidative phosphorylation in normal and regenerating rabbit liver in order to examine the acceleration mechanism of mitochondrial oxidative phosphorylation. In regenerating rabbit liver the rate of state 3 respiration, respiratory control ratio and phosphorylation rate in the presence of mM glutamate, 250 microM ADP and 3 mM inorganic phosphate increased significantly as compared with the control by 73%, 48% and 76%, respectively. The control of the rate of state 3 respiration in normal liver was exerted by Complexes I, IV and steps other than the aforementioned six steps, whose flux control coefficients were 0.317, 0.214 and 0.469, respectively. By contrast, in regenerating liver, the control was more evenly distributed among these steps in oxidative phosphorylation and the possibility is suggested that Complexes I, IV and steps other than the six steps are activated during regeneration. The activation of Complexes I and IV was attributed to their increased activity, since it was not accompanied by an increase in the amount of the enzymes.

Retinoids (all-trans and 9-cis retinoic acid) stimulate production of macrophage colony-stimulating factor and granulocyte-macrophage colony-stimulating factor by human bone marrow stromal cells

Retinoic acids (RAs) exert pleiotropic effects on cellular growth and differentiation. All-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA), a stereoisomer of ATRA, induce differentiation of leukemic cell lines and cells from patients with acute myelogenous leukemia (AML) in vitro. Despite information on the effects of RAs on hematopoietic cells, little is known about how RAs act on the hematopoietic microenvironment, especially on bone marrow stromal cells. Based on recent observations that various cytokines produced mainly by bone marrow stromal cells regulate hematopoiesis, we analyzed the effects of RAs on cytokine production by these cells. ATRA or 9-cis RA treatment of human bone marrow stromal cell line KM101, which produces macrophage colony-stimulating factor (M-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) constitutively, enhanced mRNA levels of both cytokines in a dose-dependent manner. Both RAs also stimulated M-CSF production from primary cultures of human bone marrow stromal cells. Both retinoic acid receptor (RAR)-alpha and retinoid X receptor (RXR)-alpha were expressed constitutively in KM101 cells. ATRA did not affect the expression of either receptor, whereas 9-cis RA increased RXR-alpha mRNA expression in a dose-dependent manner, but did not affect levels of RAR-alpha mRNA. These findings may have important biologic implications for both the role of RAs in hematopoiesis and the therapeutic effects of ATRA on the hematopoietic microenvironment in patients with acute promyelocytic leukemia (APL).

Brain activation study by use of positron emission tomography in unanesthetized monkeys

A system for the measurement of brain activity in conscious monkeys by positron emission tomography (PET) was established in the present study. The signal/noise ratio was maximal around 40 s for data acquisition in the PET scan with 15O-labeled water. When the monkey was stimulated by vibration and subtraction images of the data sets from regional cerebral blood flow (rCBF) changes in paired stimulation and control were superimposed on magnetic resonance images obtained from the same specimens, a somatotopic map corresponding to the sites stimulated was clearly demonstrated. Visual stimulation with a photic stimulator activated the corresponding regions of the primary visual cortex. Comparison of the activated sites and extents under the conscious state with those under anesthesia assured that the study is controllable; there was little unpredictable activation due to unlimited subject movement or to psychological effects.

A naturally occurring single basic amino acid substitution in the V3 region of the human immunodeficiency virus type 1 env protein alters the cellular host range and antigenic structure of the virus

Human immunodeficiency virus type 1 circulates in vivo as a mixture of heterologous populations (quasispecies). We previously analyzed the quasispecies of the third hypervariable region (V3) in the viral envelope glycoprotein gp120 in an infected individual and found that the species with a basic amino acid substitution (lysine for aspartic acid) at a particular position evolved and became a distinct population within a short period, followed by progression to the typical immunodeficiency stage (S. Oka et al., AIDS Res. Hum. Retroviruses 10:271-277, 1994). In the present study, we examined the biological significance of this amino acid substitution by constructing recombinant viruses with specific point mutations and comparing their replication capabilities in different cell types. The results demonstrated that the single basic amino acid substitution was sufficient to render a virus fully capable of replicating in human T-cell lines under certain conditions. With an acidic amino acid at the position, the virus grew much less fast or did not grow at all in the T-cell lines. Viral neutralization assay and peptide enzyme-linked immunosorbent assays further showed that this amino acid substitution resulted in different recognition by several of the serum specimens from human immunodeficiency virus type 1-infected individuals and thus could alter the antigenic structure. An additional finding worthy of note was that at the terminal stage, the proviral sequences of peripheral blood mononuclear cells and the viral isolates from them were without exception of the late type with the basic amino acid substitution, whereas the early sequence without the substitution was retained as a major subset in the spleen. These results support the notion that basic amino acid substitutions in V3 are a strong predictor of virus tropism and may be relevant to disease progression.

Biological characteristics of a continuous cultured cell line derived from a human malignant fibrous histiocytoma

A continuous cultured cell line, NATO, was established from a human malignant histiocytoma of bone. The cultured cells consisted of at least 3 types of tumor cells; polygonal, long spindle and occasionally giant cells, which were primarily observed in the original tumor of the patient. Ultrastructurally, they were mostly immature cells that had poorly developed cell organelles and a few lysozomal granules. The cultured cells had phagocytotic activity and were positive for acid phosphatase, transferrin receptor, alpha 1-antitrypsin, alpha-naphthyl acetate esterase and HLA-DR, but negative for Fc- and C3-receptors. Allotransplantation of the cells into athymic nude mice produced tumors at early passages, but did not 3 years later. Four cloned sublines isolated from the parent line also showed essentially an identical morphology with that of the parent cell line, indicating that the 3 cell types were interchangeable.

Diagnosis of t(2;5)(p23;q35)-associated Ki-1 lymphoma with immunohistochemistry

Some Ki-1 lymphomas carry a specific chromosomal translocation, t(2;5)(p23;q35). We have recently found a novel hyperphosphorylated 80-kD protein tyrosine kinase, p80, in a human Ki-1 lymphoma with this translocation. Subsequent cDNA cloning showed that p80 is a fusion protein of two different genes on chromosome 2p23 and 5q35, the novel tyrosine kinase gene and nucleophosmin gene, respectively. In this study, we intended to detect p80 on lymphoma tissues with immunologic methods. Thus, we developed rabbit polyclonal antibody using a synthetic peptide corresponding to a part of its kinase domain. The antibody (anti-p80) immunoprecipitated and immunoblotted p80 specifically from AMS3. Then, to examine whether t(2;5)(p23;q35) was present on biopsied lymphomas, reverse transcriptase-polymerase chain reaction (RT-PCR) covering the fusion junction of p80 mRNA was performed. Among 10 Ki-1 lymphomas and 10 additional lymphomas other than the Ki-1 lymphomas, expression of p80 mRNA was detected in three cases exclusively. When these 20 cases and additional 30 lymphomas were immunostained with anti-p80, positive staining was noted exclusively in the three cases found by PCR to have harbored the p80 mRNA. Thus, the present immunostaining, as well as PCR, was shown to be efficient for detecting lymphomas producing this chimeric protein/mRNA.

Aleutian mink disease: puzzles and paradigms

Aleutian mink disease (AD) is a naturally occurring persistent virus infection of mink caused by the Aleutian mink disease parvovirus (ADV). The classical form of AD, which occurs in adult mink, is notable for high titers of antiviral antibodies, hypergammaglobulinemia, plasmacytosis, and immune complex disease. In addition, there is a progressive renal disease characterized by mesangial proliferative glomerulonephritis and severe interstitial nephritis. Development of AD depends on both host and viral factors, and mink of certain genotypes fail to develop progressive disease when inoculated with low-virulence strains of virus. In newborn mink kits, ADV causes a fatal, acute interstitial pneumonitis associated with permissive viral replication in alveolar type 2 cells, but treatment of newborn kits with anti-viral antibody aborts the acute disease and converts into one resembling the persistent infection observed in adults. In infected adult mink, ADV is sequestered as immune complexes in lymphoid organs, but actual viral replication is restricted at the level of the individual cell and can be detected in only a small population of macrophages and follicular dendritic cells. ADV infection of mink primary macrophages and the human macrophage cell line U937 is antibody dependent and leads to the production of the cytokine interleukin-6. Furthermore, levels of interleukin-6 are increased in lymph node culture supernatants from infected mink. Chronic production of interleukin-6 may promote development of the immune disorder characteristic of AD.

Rearrangement of bcl-2 is detectable in Hodgkin's disease by polymerase chain reaction

The authors examined the occurrence of the t(14;18) chromosomal translocation in 44 cases of Hodgkin's disease (HD) using the polymerase chain reaction and Southern blot hybridization with non-radioactive oligonucleotide probes. DNAs were extracted from unfixed, fresh-frozen and formalin-fixed, paraffin-embedded biopsy specimens. Southern blot hybridization of the amplification product showed that, of 44 HD DNAs, three had a detectable t(14;18) breakpoint at the mbr (major breakpoint region), while none had a detectable t(14;18) breakpoint at the mcr (minor cluster region). Of the three cases positive for a t(14;18) breakpoint at the mbr, two were of lymphocyte predominance type, and the other was of mixed cellularity type.

Multi-segmental and generalized suppression of postural muscle tone evoked by stimulating the dorsal tegmental field and the medial pontine reticular formation in acute decerebrate cats

In acute decerebrate cat, stimulation of the dorsal tegmental field (DTF) of the caudal pons along its midline and the medial pontine reticular formation (mPRF) evokes generalized suppression of postural muscle tone. In this study, the effects of stimulation of the DTF area were compared with those evoked by stimulating the mPRF unilaterally or bilaterally. By stimulating the mPRF bilaterally, simultaneous suppression of tonic activities in the neck, lumbar back, forelimb and hindlimb muscles, bilaterally, was evoked as that evoked by stimulating the DTF area alone.