Substituent effects of beta-diketiminate ligands on the structure and physicochemical properties of copper(II) complexes

Substituent effects of beta-diketiminate ligands on the structure and physicochemical properties of the copper(II) complexes have been systematically investigated by using 3-iminopropenylamine derivatives R1LR3H, R3-N=CH-C(R1)=CH-NH-R3, where R1 is Me, H, CN, or NO2, and R3 is Ph, Mes (mesityl), Dep (2,6-diethylphenyl), Dipp (2,6-diisopropylphenyl), or Dtbp (3,5-di-tert-butylphenyl). When the ligands with R3=Ph or Dtbp were treated with CuII(OAc)2, bis(beta-diketiminate) copper(II) complexes exhibiting distorted tetrahedral geometries were obtained, the crystal structures of which were nearly the same as each other regardless of the alpha-substituent (R1); dihedral angles between the two beta-diketiminate coordination planes are 62.5 +/- 1.2 degrees, and the Cu-N bond lengths are 1.959 +/- 0.008 A. The distorted tetrahedral structures are maintained in solution, but the spectroscopic features, especially gII values of the ESR spectra and the d-d bands of the absorption spectra, as well as the electrochemical behaviors of the complexes, are significantly affected by the electronic nature of R1. The ligands with R3=Mes and Dep, on the other hand, gave di(mu-hydroxo)dicopper(II) complexes, and their crystal structures as well as spectroscopic and electrochemical features have also been explored. Furthermore, the ligand with the more sterically encumbered aromatic substituent (Dipp) provided a mononuclear four-coordinate square planar copper(II) complex supported by one beta-diketiminate ligand and one didentate acetate ion. Thus, the beta-diketiminate ligands with a variety of substituents (R1 and R3) have been explored to provide coordinatively unsaturated (four-coordinate) mononuclear and dinuclear copper(II) complexes with significantly different coordination geometry and properties.

Carbamazepine-induced hypersensitivity syndrome associated with transient hypogammaglobulinaemia and reactivation of human herpesvirus 6 infection demonstrated by real-time quantitative polymerase chain reaction

Drug-induced hypersensitivity syndrome (HS) is a rare but severe disease with multiorgan failure. Many different precipitating factors have been reported, but the pathophysiology of HS remains unknown. However, the association of the human herpesvirus (HHV) family, particularly of HHV-6, has recently been reported in patients with HS. We report a 14-year-old boy who was diagnosed as having carbamazepine-induced HS based on the clinical course, laboratory data and results of drug-induced lymphocyte stimulation tests. In addition, the reactivation of HHV-6 was demonstrated by real-time quantitative polymerase chain reaction and by significantly increased levels of the specific antibody in his paired sera. Furthermore, transient hypogammaglobulinaemia was detected in the early stage of the disease. In addition, serum levels of interferon-gamma, interleukin (IL)-6, IL-5 and eosinophil cationic protein, which were increased on admission, decreased dramatically after steroid therapy. This is the first report of carbamazepine-induced HS associated with reactivation of HHV-6, transient hypogammaglobulinaemia, increased serum levels of inflammatory cytokines and activated eosinophils. This case might contribute to the understanding of the pathophysiology of HS.

Selective insufficiency of IFN-gamma secretion in patients with hyper-IgE syndrome

BACKGROUND

Hyper-immunoglobulin E (IgE) syndrome is a complex immune deficiency characterized by chronic eczematous dermatitis, recurrent staphylococcal infections, pneumatoceles, reduced neutrophil chemotaxis, and variably impaired T cell function. Although decreased interferon-gamma (IFN-gamma) production in patients with hyper-IgE syndrome is pointed out and known as a cause of reduced neutrophil chemotaxis, precise mechanism of their inadequate production of IFN-gamma remains unknown. To elucidate the pathogenesis of the defective production of IFN-gamma in patients with hyper-IgE syndrome, we assessed the in vitro production and secretion of IFN-gamma by peripheral blood mononuclear cells (PBMCs) from patients with hyper-IgE syndrome.

METHODS

Chemotaxis of neutrophils, mRNA levels of several cytokines, intracellular production and extracellular secretion of IFN-gamma, interleukin-2 (IL-2), and IL-4 by PBMCs from three patients with hyper-IgE syndrome were determined.

RESULTS

The transcription of IFN-gamma mRNA and the production of its protein molecules progressed normally. However, selective insufficiency in the secretion of IFN-gamma molecules was found in patients with hyper-IgE syndrome. Confocal laser scanning microscopy clearly demonstrated the accumulation of IFN-gamma in patients with hyper-IgE syndrome.

CONCLUSION

We demonstrated that there was a selective insufficiency in the secretion of IFN-gamma in patients with hyper-IgE syndrome. We hope that this fact would offer a new paradigm for understanding this disease.

Interferon-gamma downregulates Hsp27 expression and suppresses the negative regulation of cell death in oral squamous cell carcinoma lines

Interferon-gamma (IFN-gamma) induced cell death in five oral squamous cell carcinoma (SCC) lines. Cell death was specific to IFN-gamma treatment and did not occur with either IFN-alpha or TNF-alpha. IFN-gamma did not induce typical apoptotic phenotype in cells, such as morphological changes and DNA ladder formation. Caspase-3 was partially activated by IFN-gamma. Protein levels of molecular chaperones were examined in cells treated with IFN-gamma. Among these, levels of heat shock protein 27 (Hsp27) were specifically reduced upon IFN-gamma treatment of oral SCC cells. Recombinant clones overexpressing Hsp27 were more resistant to IFN-gamma-induced cell death than parent cells. Conversely, cells expressing a dominant-negative mutant of Hsp27, in which three serine residues (15, 78 and 82) were replaced by glycine, were hypersensitive to the effects of IFN-gamma and exhibited a typical apoptotic phenotype. Pretreatment of cells with IFN-gamma enhanced apoptotic cell death induced by cisplatin. Our data suggest that IFN-gamma suppresses Hsp27 expression in oral SCC cells and blocks the inhibitory effects of this molecular chaperone on apoptotic cell death. Moreover, IFN-gamma initiates the transition of oral SCC cells to the proapoptotic and/or aborted apoptotic state. Hsp27 plays a crucial role in the inhibition of apoptosis of oral SCC cells. Our findings highlight the importance of employing IFN-gamma in combination with certain anticancer drugs as treatments for oral cancer. We suggest that Hsp27 plays a significant role in the IFN-gamma-induced sensitization of oral SCC cells to anticancer drugs.

Release of recombinant human bone morphogenetic protein 2 from a newly developed carrier

After implantation of a polymer-coated gelatin sponge (PGS) containing either 0.4 or 1.0 mg of 125I-rhBMP-2 for each 1 cm(3) of PGS into the right ulnar of rabbits, changes in the level of radioactivity at the implant site and in the blood were measured for 21 days after implantation, and the cumulative excretion ratio of radioactivity in the urine and feces was calculated. For both doses, radioactivity at the implant site was eliminated biphasically. The concentration of trichloroacetic acid (TCA)-precipitable radioactivity in the blood reached a maximum 6 h after implantation, at which time it was equivalent to 1.41% of the administered dose (0.4 mg/cm(3)). The remaining radioactivity was eliminated rapidly thereafter, falling below the detection limit within 48 h. The t(1/2alpha) was about 0.1 days, the t(1/2beta) was about 3 days, and the mean resident time (MRT) value was about 4 days. By 17 days after implantation, 88.1% of the administered radioactivity had been excreted in the urine, and 1.7% had been excreted in the feces. TCA precipitation test results indicated that most of the radioactivity excreted in urine was a low-molecular weight decomposition product. At 21 days after implantation, the radioactivity of the PGS implant site had declined to 0.5% of the administered amount. Autoradiographs of the implant site taken 28 days after implantation revealed that, at both doses, the residual radioactivity was confined to the area of the implanted PGS. These results indicate that PGS retains an appropriate amount of recombinant human bone morphogenetic protein 2 (rhBMP-2) at the orthotopically implanted site for at least 21 days enough to induce bone regeneration. Thus, PGS shows great clinical potential as a carrier for rhBMP-2.

Split chimerism after allogeneic bone marrow transplantation in Chediak-Higashi syndrome

Chediak-Higashi Syndrome (CHS) is a hereditary multiorgan disease associated with a lymphoproliferative disorder termed 'accelerated phase' (AP). As AP is often life-threatening, hematopoietic stem cell transplantation has been proposed as the only curative treatment for CHS. Here, we report a 1-year-old Japanese boy with CHS who received an HLA-matched unrelated BMT at the AP stage, which resulted in split chimerism. We evaluated the chimerism status of isolated leukocytes and found that only a limited population of T and NK cells was of donor origin and the majority of these and other hematopoietic cells was of host origin. Clinical outcome was successful, and the patient is currently alive and well, free of AP and serious infections more than 18 months after BMT.

Copper chemistry of beta-diketiminate ligands: monomer/dimer equilibria and a new class of bis(mu-oxo)dicopper compounds

A series of Cu(I) and Cu(II) complexes of a variety of beta-diketiminate ligands (L(-)) with a range of substitution patterns were prepared and characterized by spectroscopic, electrochemical, and, in several cases, X-ray crystallographic methods. Specifically, complexes of the general formula [LCuCl](2) were structurally characterized and their magnetic properties assessed through EPR spectroscopy of solutions and, in one instance, by variable-temperature SQUID magnetization measurements on a powder sample. UV-vis spectra indicated reversible dissociation to 3-coordinate monomers LCuCl in solution at temperatures above -55 degrees C. The Cu(I) complexes LCu(MeCN) exhibited reversible Cu(I)/Cu(II) redox couples with E(1/2) values between +300 and +520 mV versus NHE (cyclic voltammetry, MeCN solutions). These complexes were highly reactive with O(2), yielding intermediates that were identified as rare examples of neutral bis(mu-oxo)dicopper complexes on the basis of their EPR silence, diagnostic UV-vis absorption data, and O-isotope-sensitive resonance Raman spectroscopic features. The structural features of the compounds [LCuCl](2) and LCu(MeCN) as well as the proclivity to form bis(mu-oxo)dicopper products upon oxygenation of the Cu(I) complexes are compared to data previously reported for complexes of more sterically hindered beta-diketiminate ligands (Aboelella, N. W.; Lewis, E. A.; Reynolds, A. M.; Brennessel, W. W.; Cramer, C. J.; Tolman, W. B. J. Am. Chem. Soc. 2002, 124, 10600. Spencer, D. J. E.; Aboelella, N. W.; Reynolds, A. M.; Holland, P. L.; Tolman, W. B. J. Am. Chem. Soc. 2002, 124, 2108. Holland, P. L.; Tolman, W. B. J. Am. Chem. Soc. 1999, 121, 7270). The observed structural and reactivity differences are rationalized by considering the steric influences of both the substituents on the flanking aromatic rings and those present on the beta-diketiminate backbone.

Increased expression of cytosolic chaperonin CCT in human hepatocellular and colonic carcinoma

The chaperonin-containing t-complex polypeptide 1 (CCT) is a hetero-oligomeric molecular chaperone that assists in the folding of actin, tubulin, and other cytosolic proteins. We recently reported that the expression level of CCT is closely correlated with growth rates of mammalian cultured cells. Here we examine the levels of CCT subunits and other molecular chaperones in tumor tissues of patients with hepatocelluar and colonic carcinoma, and compare them with nontumor tissues in the same patients. Expression levels of CCTbeta in tumor tissues was significantly higher than in nontumor tissues in all patients with hepatocellular carcinoma (n = 15) and 83% of patients with colonic carcinoma (n = 17). The increased level of CCT expression in colonic cancer cells was confirmed by immunohistochemistry with anti-CCTbeta antibody. The levels of CCTbeta were highly correlated (r = 0.606) with those of the proliferating cell nuclear antigen (PCNA), which was used as an indicator of cell growth. CCTalpha gave similar results, although the correlation with PCNA levels was weaker. Other cytosolic and endoplasmic reticulum chaperones also showed higher expression in significant numbers of tumor tissues but less frequently than that observed with CCT. These results suggest that CCT is up-regulated in rapidly proliferating tumor cells in vivo to effectively produce proteins required for growth, and may serve as a useful tumor marker because it is widely distributed in the cytosol.

Increased expression of cytosolic chaperonin CCT in human hepatocellular and colonic carcinoma

The chaperonin-containing t-complex polypeptide 1 (CCT) is a hetero-oligomeric molecular chaperone that assists in the folding of actin, tubulin, and other cytosolic proteins. We recently reported that the expression level of CCT is closely correlated with growth rates of mammalian cultured cells. Here we examine the levels of CCT subunits and other molecular chaperones in tumor tissues of patients with hepatocelluar and colonic carcinoma, and compare them with nontumor tissues in the same patients. Expression levels of CCTbeta in tumor tissues was significantly higher than in nontumor tissues in all patients with hepatocellular carcinoma (n = 15) and 83% of patients with colonic carcinoma (n = 17). The increased level of CCT expression in colonic cancer cells was confirmed by immunohistochemistry with anti-CCTbeta antibody. The levels of CCTbeta were highly correlated (r = 0.606) with those of the proliferating cell nuclear antigen (PCNA), which was used as an indicator of cell growth. CCTalpha gave similar results, although the correlation with PCNA levels was weaker. Other cytosolic and endoplasmic reticulum chaperones also showed higher expression in significant numbers of tumor tissues but less frequently than that observed with CCT. These results suggest that CCT is up-regulated in rapidly proliferating tumor cells in vivo to effectively produce proteins required for growth, and may serve as a useful tumor marker because it is widely distributed in the cytosol.

Differential display of skin mRNAs regulated under varying environmental conditions in a mudskipper

To understand the molecular mechanisms underlying the terrestrial adaptation, as well as adaptation to different salinities, of the euryhaline and amphibious mudskipper ( Periophthalmus modestus), we have looked for the skin mRNAs that change during varying environmental conditions. Using differential mRNA display polymerase chain reaction, we compared skin mRNAs in mudskipper transferred from isotonic 30% seawater to fresh water or to seawater for 1 day and 7 days, as well as those kept out of water for 1 day. At the end of these periods, poly(A(+))RNA was prepared from the Cl(-)-secreting pectoral skins and also from the outer opercular skins where ion transport is negligible, and analyzed by differential display. We identified four cDNA products expressed differently under various environments as homologues of known genes. A further 34 cDNAs were expressed differentially, but they have no significant homology to identified sequences in GenBank. Northern blots demonstrate that mRNA levels of the actin-binding protein and the platelet-activating factor acetylhydrolase increased in the pectoral skins during seawater acclimation. The mRNA of the 90 kDa heat shock protein was down-regulated in water-deprived and freshwater fish, whose plasma cortisol levels were high. The aldolase mRNA was induced in both skins after desiccation. These four genes may be involved in the environmental adaptations.

[Lateral femoral circumflex artery for coronary artery bypass surgery in a patient receiving hemodialysis: report of a case]

A 59-year-old man receiving hemodialysis had a 2-vessel coronary disease. We performed double coronary artery bypass grafting with the left internal thoracic artery to the left anterior descending artery, and the composite graft of right internal thoracic artery and lateral femoral circumflex artery to the right coronary artery. Postoperative coronary angiogram showed that the LFCA bypass graft was widely patent and supplied sufficient blood to the anastomosed vessel. There was no stenosis at the anastomotic site. He had no postoperative complication. Long-term follow-up and more cases is necessary to establish the usefulness of LFCA as an arterial free graft for coronary revascularization in patients receiving hemodialysis.

Oxidative degradation of beta-diketiminate ligand in copper(II) and zinc(II) complexes

Copper(II) and zinc(II) complexes supported by a popular beta-diketiminate ligand (1(-), 2-mesitylamino-4-mesitylimino-2-pentene), [CuII(1)(AcO)] and [[ZnII(1)]2(mu-MeO)(mu-AcO)], have been demonstrated to undergo an oxidative degradation to give a ketone diimine derivative (2) under aerobic conditions. The crystal structures of the mononuclear copper(II) and dinuclear zinc(II) complexes of the beta-diketiminate ligand as well as the copper(II) complex of the modified ligand have been determined by X-ray crystallographic analysis. Mechanism for the oxidative degradation reaction of the beta-diketiminate ligand is also discussed.

Morphological changes and cellular dynamics of oligodendrocyte lineage cells in the developing vertebrate central nervous system

Oligodendrocyte precursor cells (OPCs) originate in multiple restricted regions of the developing central nervous system (CNS). Here, we focus on morphological changes of oligodendrocyte lineage cells and their cellular dynamics including cell motility and proliferation. Morphological studies with molecular markers for OPCs suggest distinct spatiotemporal patterns of OPC migration in vivo, which are directly demonstrated by application of exogenous fluorescent markers to OPCs. Extensive proliferation of OPCs in the CNS parenchyma is also demonstrated by pulse labeling of the cells with bromodeoxyuridine. The results strongly suggest that oligodendrocyte lineage cells are highly motile and actively proliferate with an elongated morphology. These data provide insights into the potential molecular mechanisms of OPC dispersal throughout the CNS.

An ARL1 mutation affected autophagic cell death in yeast, causing a defect in central vacuole formation

When the cdc28 strain of Saccharomyces cerevisiae is incubated at restrictive temperatures, the yeasts digest themselves in 7 days by activating autophagic machinery. In parallel, the cell-proliferative activity decreases progressively after about 48 h. We have previously referred to this phenomenon as autophagic death. In the present study, we isolated and characterized a recessive mutant strain, dlp2, which delays the progression toward autophagic death. The cdc28 dlp2 cells contain many small vesicles instead of the large central vacuoles that are usually found in parental cdc28 cells. We showed that the dlp2 phenotype results from the presence of a single mutation in the gene ARL1 (ADP-ribosylation factor-like protein 1). Morphological and biochemical analyses of cdc28 dlp2 suggested that a defect in central vacuole formation is caused by aberrant membrane trafficking, although the protein-sorting to vacuoles is not affected. After a shift to a restrictive temperature, the components of the cytoplasm and nucleus of cdc28 dlp2 were condensed, with an accompanying formation of vesicles in the periphery (epiplasm) of the cells rather than an activation of the autophagic machinery. Introducing this ARL1 mutation into the normal ARL1 locus of the wild-type W303 strain again inhibited the progression of apoptotic cell death due to a defect in vacuole formation, which in this case was induced by the proapoptotic protein Bax. Thus, the ARL1 gene plays an important role in the formation of central vacuoles and in the progression of programmed cell death induced by cell-cycle arrest or Bax. These results suggested the presence of a programmed-cell death machinery in yeast that is similar to that related to the Type II cell death of mammalian cells characterized by autophagocytosis.

Projections from the red nucleus to the parvicellular reticular formation and the cervical spinal cord in the rat, with special reference to innervation by branching axons

After biotinylated dextranamine injection into the dorsal part of the red nucleus (RN) in the rat, labeled axons were distributed contralaterally in the lateral tegmental field including the parvicellular reticular formation (RFp), and ipsilaterally in the medial reticular formation. In the cervical spinal cord, labeled axons were present bilaterally with a contralateral dominance mainly in laminae V-VI and the dorsal part of laminae VII. After ipsilateral injections of rhodamine dextranamine, Fluoro-ruby (FR) into the RFp and Fluoro-gold (FG) into the upper cervical spinal cord, a population of FR-labeled neurons was found in the dorsal part of the contralateral RN, whereas the majority of FG-labeled neurons were located more ventrally. However, some of them were intermingled with FR-labeled neurons, and as many as one-third of FR-labeled neurons were labeled with FG. After combined injections of FR into the RFp and FG into the lower cervical spinal cord, RN neurons labeled with FG existed more ventrally than those retrogradely labeled from the upper cervical spinal cord, and less than 10% of FR-labeled neurons were labeled with FG. The present data suggest that axon collateral innervation of the RFp and the upper cervical spinal cord by single RN neurons may be responsible for coordinating head and orofacial movements.

Evaluation of ceramics composed of different hydroxyapatite to tricalcium phosphate ratios as carriers for rhBMP-2

We have investigated pellet-shaped implants prepared from biphasic calcium phosphate (BCP) ceramics with five different ratios of hydroxyapatite (HAP) to beta tricalcium phosphate (beta-TCP). The purpose of this study was to evaluate these BCP ceramics as carriers for rhBMP-2. BCP ceramics impregnated with the different doses of recombinant human bone morphogenetic protein 2 (rhBMP-2) (1, 5 and 10g) were used for the experimental purpose and the ceramics without rhBMP-2 were used as control. The pellets were placed into subcutaneous pockets on the dorsum of 4-week-old male Wistar rats. The animals were sacrificed 2 and 4 weeks after implantation. Bone induction was estimated by alkaline phosphatase (ALP) activity measured at 2 weeks after implantation. Pellets were also examined radiologically, histologically and histomorphometrically. The results showed that all experimental pellets exhibited new bone formation whereas the control pellets produced only fibrous connective tissue. Here, 100% HAP ceramic showed most amount of bone formation, whereas 25% HAP to 75% TCP ceramic produced the bone least in amount among different BCP ceramics at the end of 4 weeks. This study indicates that formation of new bone depends on the ceramic content with high HAP-TCP ratio and high dose of rhBMP-2.

Regulation of the ion-transporting mitochondrion-rich cell during adaptation of teleost fishes to different salinities

The mitochondrion-rich cells (MRCs) in teleost gill and equivalent tissues are important osmoregulatory sites in maintaining ionic balance. These cells express a variety of ion pumps, transporters, and channels, which play central roles in ionic regulation. Recently, two types of MRCs have been identified in euryhaline fishes: seawater (SW)-type MRCs extrude Na and Cl ions in SW conditions; freshwater (FW)-type MRCs take up at least Cl-. Long-term development/differentiation of the two types of MRCs during adaptation to different salinities appears to be regulated mainly by endocrine factors. Osmolality, Ca2+, neurotransmitters, and fast-acting hormones rapidly regulate the SW MRCs. Recent information is assembled in this review and suggests the functional plasticity of highly specialized MRCs.

[Clinical study of 33 children with systemic pneumococcal infections]

We retrospectively analyzed 33 cases of children with systemic pneumococcal infections, 22 bacteremia and 11 meningitis, diagnosed and treated in Asahi General Hospital between 1985 and 1999. The median age at diagnosis was 15 months old and the incidence peaked in infants between 7 and 24 months of age (57.6%). Two cases showed low serum IgG2 levels. Fever was a common symptom in all cases and 13 (39.4%) presented convulsions. Meningitis [median age: 10 months] tended to occur, if not significant, in younger children than bacteremia [16 months]. All cases of meningitis were diagnosed 12 hours or later after the onset of fever, though 54.5% of the cases of bacteremia were diagnosed within 12 hours. The cases of meningitis showed statistically lower white blood cell counts [median: 9,700/mm3] and higher CRP levels [median: 25.6 mg/dl] than those of bacteremia [23,900/mm3 and 4.2 mg/dl, respectively] at diagnosis. Although all cases of bacteremia were cured without any sequelae by antibiotic treatment, 3 cases (27.3%) of meningitis died and 4 (36.4%) developed severe neurological sequelae. Our findings suggest that the putative pathogenesis by which pneumococcal meningitis results from bacteremia and, taking in the account of the poor outcome of meningitis, may justify the early antibiotic intervention against pneumococcal bacteremia.

Frequency of food-dependent, exercise-induced anaphylaxis in Japanese junior-high-school students

BACKGROUND

Food-dependent, exercise-induced anaphylaxis (FEIAn) is classified among the physical allergies. The pathophysiology of FEIAn remains unknown, as does the frequency of FEIAn in the general population.

OBJECTIVE

We sought to study the epidemiology of FEIAn, especially its frequency in junior-high-school students in Yokohama, Japan.

METHODS

A questionnaire asking about the occurrence of FEIAn in school students was sent to all 145 public junior-high-school nurses in Yokohama.

RESULTS

One hundred thirty-two junior-high-school nurses responded to the questionnaire, and 13 (11 boys and 2 girls) cases of FEIAn among 76,229 junior-high-school students were reported. In addition, 24 (12 boys and 12 girls) subjects with exercise-induced anaphylaxis (EIAn) were detected. From this survey, the frequency of FEIAn was 0.017% in this population, and its frequency was significantly higher in boys than in girls (P < .05). The frequency of EIAn was 0.031%, and there was no difference according to sex. Only one third of junior-high-school nurses had any knowledge of FEIAn. We also performed provocation tests in 5 of the 13 cases with FEIAn after obtaining informed consent from the students and their parents and were able to confirm the diagnosis.

CONCLUSION

This study showed that FEIAn and EIAn are relatively rare diseases among junior-high-school students in Yokohama. To avoid serious outcomes, we believe it is important that not only physicians but also school nurses and teachers of physical education be aware of these diseases.

Evidence for distinct membrane traffic pathways to melanosomes and lysosomes in melanocytes

We report here morphologic and biochemical evidence that melanosomes are distinct from lysosomes. Immunofluorescence analysis revealed that TRP-1, a melanosomal membrane protein, did not colocalize with lysosomal membrane proteins LAMP1 and LGP85 in melan-a cells. Wortmannin treatment of melanocytes enhanced the distinct compartmentalization of these melanosomal/lysosomal membrane proteins by the swelling of the endosomal-lysosomal systems. The heavily melanized melanosomes did not have an altered shape, which suggests a lesser degree of membrane dynamics of stage IV melanosomes. Terminal lysosomes loaded with TR-dextran are also distinct from melanosomes, thus indicating that melanosomes are isolated from the endocytic pathway that is a representative route to lysosomes. Because AP-3 mutation leads to mistargeting of both melanosome and lysosome membrane proteins, we propose that there is a late sorting step for melanosomes and lysosomes in melanocytes after AP-3 sorting.

Autophagosome requires specific early Sec proteins for its formation and NSF/SNARE for vacuolar fusion

Double membrane structure, autophagosome, is formed de novo in the process of autophagy in the yeast Saccharomyces cerevisiae, and many Apg proteins participate in this process. To further understand autophagy, we analyzed the involvement of factors engaged in the secretory pathway. First, we showed that Sec18p (N-ethylmaleimide-sensitive fusion protein, NSF) and Vti1p (soluble N-ethylmaleimide-sensitive fusion protein attachment protein, SNARE), and soluble N-ethylmaleimide-sensitive fusion protein receptor are required for fusion of the autophagosome to the vacuole but are not involved in autophagosome formation. Second, Sec12p was shown to be essential for autophagy but not for the cytoplasm to vacuole-targeting (Cvt) (pathway, which shares mostly the same machinery with autophagy. Subcellular fractionation and electron microscopic analyses showed that Cvt vesicles, but not autophagosomes, can be formed in sec12 cells. Three other coatmer protein (COPII) mutants, sec16, sec23, and sec24, were also defective in autophagy. The blockage of autophagy in these mutants was not dependent on transport from endoplasmic reticulum-to-Golgi, because mutations in two other COPII genes, SEC13 and SEC31, did not affect autophagy. These results demonstrate the requirement for subgroup of COPII proteins in autophagy. This evidence demonstrating the involvement of Sec proteins in the mechanism of autophagosome formation is crucial for understanding membrane flow during the process.

Multiple bone lesions after allogeneic bone marrow transplantation in a patient with relapsed adult acute lymphoblastic leukemia: minimal residual disease analysis may predict extramedullary relapse

We describe a patient with acute lymphoblastic leukemia (ALL, L2) who relapsed with multiple bone lesions after allogeneic bone marrow transplantation (allo-BMT). Allo-BMT was performed from an HLA-identical sibling during the first hematological complete remission (CR). Minimal residual disease (MRD) assessed by polymerase chain reaction (PCR) with primers for T cell receptor delta (TCRdelta) gene became positive in the bone marrow sample on day 46 after allo-BMT. On day 113, the patient complained of a painful tumor at the right clavicle. The examination of biopsy specimen revealed infiltration of leukemic cells. After partial response was achieved by local radiotherapy, disseminated bone lesions were demonstrated by 99mTC scintigraphy scan, followed by bone marrow relapse on day 137. The patient died of cardiac tamponade on day 236 after Allo-BMT. MRD assessed by PCR assay for TCRdelta gene in the bone marrow is useful for the prediction of extramedullary as well as medullary relapse after BMT.

Physical and inflammatory stressors elevate circadian clock gene mPer1 mRNA levels in the paraventricular nucleus of the mouse

Stress induces secretion of corticosterone through activation of the hypothalamic-pituitary-adrenal axis. This corticosterone secretion is thought to be controlled by a circadian clock in the suprachiasmatic nucleus (SCN). The hypothalamic paraventricular nucleus (PVN) receives convergent information from both stress and the circadian clock. Recent reports demonstrate that mammalian orthologs (Per1, Per2, and Per3) of the Drosophila clock gene Period are expressed in the SCN, PVN, and peripheral tissues. In this experiment, we examined the effect of physical and inflammatory stressors on mPer gene expression in the SCN, PVN, and liver. Forced swimming, immobilization, and lipopolysaccharide injection elevated mPer1 gene expression in the PVN but not in the SCN or liver. A stress-induced increase in mPer1 expression was observed in the corticotropin-releasing factor-positive cells of the PVN; however, the stressors used in this study did not affect mPer2 expression in the PVN, SCN, or liver. The present study suggests that a stress-induced disturbance of circadian corticosterone secretion may be associated with the stress-induced expression of mPer1 mRNA in the PVN.

Clinical evaluation of anti-tuberculous glycolipid immunoglobulin G antibody assay for rapid serodiagnosis of pulmonary tuberculosis

Previously we reported the development of a highly sensitive enzyme-linked immunosorbent assay specific for anti-tuberculous glycolipid (anti-TBGL) for the rapid serodiagnosis of tuberculosis. In this study, the usefulness of an anti-TBGL antibody assay kit for rapid serodiagnosis was evaluated in a controlled multicenter study. Antibody titers in sera from 318 patients with active pulmonary tuberculosis (216 positive for Mycobacterium tuberculosis in smear and/or culture tests and 102 smear and culture negative and clinically diagnosed), 58 patients with old tuberculosis, 177 patients with other respiratory diseases, 156 patients with nonrespiratory diseases, and 454 healthy subjects were examined. Sera from 256 younger healthy subjects from among the 454 healthy subjects were examined as a control. When the cutoff point of anti-TBGL antibody titer was determined as 2.0 U/ml, the sensitivity for active tuberculosis patients was 81.1% and the specificity was 95.7%. Sensitivity in patients with smear-negative and culture-negative active pulmonary tuberculosis was 73.5%. Even in patients with noncavitary minimally advanced lesions, the positivity rate (60.0%) and the antibody titer (4.6 +/- 9.4 U/ml) were significantly higher than those in the healthy group. These results indicate that this assay using anti-TBGL antibody is useful for the rapid serodiagnosis of active pulmonary tuberculosis.

Increased expression of cytosolic chaperonin CCT in human hepatocellular and colonic carcinoma

The chaperonin-containing t-complex polypeptide 1 (CCT) is a hetero-oligomeric molecular chaperone that assists in the folding of actin, tubulin, and other cytosolic proteins. We recently reported that the expression level of CCT is closely correlated with growth rates of mammalian cultured cells. Here we examine the levels of CCT subunits and other molecular chaperones in tumor tissues of patients with hepatocelluar and colonic carcinoma, and compare them with nontumor tissues in the same patients. Expression levels of CCTbeta in tumor tissues was significantly higher than in nontumor tissues in all patients with hepatocellular carcinoma (n = 15) and 83% of patients with colonic carcinoma (n = 17). The increased level of CCT expression in colonic cancer cells was confirmed by immunohistochemistry with anti-CCTbeta antibody. The levels of CCTbeta were highly correlated (r = 0.606) with those of the proliferating cell nuclear antigen (PCNA), which was used as an indicator of cell growth. CCTalpha gave similar results, although the correlation with PCNA levels was weaker. Other cytosolic and endoplasmic reticulum chaperones also showed higher expression in significant numbers of tumor tissues but less frequently than that observed with CCT. These results suggest that CCT is up-regulated in rapidly proliferating tumor cells in vivo to effectively produce proteins required for growth, and may serve as a useful tumor marker because it is widely distributed in the cytosol.

Analysis of Ig subclass deficiency: First reported case of IgG2, IgG4, and IgA deficiency caused by deletion of C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon in a Mongoloid patient

BACKGROUND

The cause of Ig class or subclass deficiencies has been unclear except for IgH gene deletions and a homozygous 1-base insertion (1793insG) in C gamma 2 exon 4 of IgG2 deficiency. In addition, there are no reports that IgH gene deletions are found in patients who are Mongoloid (a category that includes most of the people of Asia, such as the Japanese, Chinese, Indonesians and Malaysians).

OBJECTIVE

To investigate the cause of Ig subclass deficiency, we extensively investigated 4 Japanese patients with low serum IgG2 levels. Patient 1 was a 23-month-old girl whose serum IgG2, IgG4, and IgA levels were under the detection limits; she also had idiopathic thrombocytopenic purpura. Patient 2 was a 5-year-old boy whose serum IgG2 level was under the detection limit. Patient 3 was a 14-month-old boy whose serum IgG2 and IgG4 levels were under the detection limits. Patient 4 was 3-year-old girl whose IgG2 level was low and whose IgA level was under the detection limit.

METHODS

DNA was extracted from neutrophils, and Southern blot analysis was performed.

RESULTS

Southern blot analysis revealed that patient 1 had lost the C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon genes and was a homozygous carrier of the deletion described above. Her mother was of the heterozygous genotype. DNA from patients 2, 3, and 4 revealed no deletions in comparison with control DNA.

CONCLUSION

This is a report of the first case of a Mongoloid in whom IgG2, IgG4, and IgA deficiency was caused by deletion of C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon. Our finding contributes to investigations of Ig subclass deficiency.

[Small lymphocytic lymphoma/chronic lymphocytic leukemia with t(11;14)]

A 83-year-old woman was referred to our hospital because of swollen lymph nodes, marked splenomegaly, and bone marrow abnormality. Histological examination of the lymph nodes revealed characteristic findings for small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL). The immunophenotype of the tumor cells was CD5+, 10-, 19+, 20+, 23-, IgM+D+. Interphase fluorescent in situ hybridization (FISH) detected t(11;14), and immunohistochemical studies demonstrated cyclin D1 expression. In both SLL/CLL and mantle cell lymphoma (MCL), the normal counterpart of the tumor cells is thought to be CD5-positive B1 cells. The present case may therefore have been borderline between SLL/CLL and MCL.

Cytosolic chaperonin-containing t-complex polypeptide 1 changes the content of a particular subunit species concomitant with substrate binding and folding activities during the cell cycle

The chaperonin-containing t-complex polypeptide 1 (CCT) is a cytosolic molecular chaperone composed of eight subunits that assists in the folding of actin, tubulin and other cytosolic proteins. We show here that the content of particular subunits of CCT within mammalian cells decreases concomitantly with the reduction of chaperone activity during cell cycle arrest at M phase. CCT recovers chaperone activity upon resumption of these subunits after release from M phase arrest or during arrest at S phase. The levels of alpha, delta and zeta-1 subunits decreased more rapidly than the other subunits during M phase arrest by colcemid treatment and recovered after release from the arrest. Gel filtration chromatography or native (nondenaturing) PAGE analysis followed by immunoblotting indicated that the alpha and delta subunit content in the 700- to 900-kDa CCT complex was appreciably lower in the M phase cells than in asynchronous cells. In vivo, the CCT complex of M-phase-arrested cells was found to bind lower amounts of tubulin than that of asynchronous cells. In vitro, the CCT complex of M phase-arrested cells was less active in binding and folding denatured actin than that of asynchronous cells. On the other hand, the CCT complex of asynchronous cells (a mixture of various phases of cell cycle) exhibited lower alpha and delta subunit content and lower chaperone activity than that of S-phase-arrested cells obtained by excess thymidine treatment. In addition, turnover (synthesis and degradation) rates of the alpha and delta subunits in vivo were more rapid than those of most other subunits. These results suggest that the content of alpha and delta subunits of CCT reduces from the complete active complex in S phase cells to incomplete inactive complex in M phase cells.

Localization of cytosolic NADP-dependent isocitrate dehydrogenase in the peroxisomes of rat liver cells: biochemical and immunocytochemical studies

Two types of NADP-dependent isocitrate dehydrogenases (ICDs) have been reported: mitochondrial (ICD1) and cytosolic (ICD2). The C-terminal amino acid sequence of ICD2 has a tripeptide peroxisome targeting signal 1 sequence (PTS1). After differential centrifugation of the postnuclear fraction of rat liver homogenate, approximately 75% of ICD activity was found in the cytosolic fraction. To elucidate the true localization of ICD2 in rat hepatocytes, we analyzed the distribution of ICD activity and immunoreactivity in fractions isolated by Nycodenz gradient centrifugation and immunocytochemical localization of ICD2 antigenic sites in the cells. On Nycodenz gradient centrifugation of the light mitochondrial fraction, ICD2 activity was distributed in the fractions in which activity of catalase, a peroxisomal marker, was also detected, but a low level of activity was also detected in the fractions containing activity for succinate cytochrome C reductase (a mitochondrial marker) and acid phosphatase (a lysosomal marker). We have purified ICD2 from rat liver homogenate and raised a specific antibody to the enzyme. On SDS-PAGE, a single band with a molecular mass of 47 kD was observed, and on immunoblotting analysis of rat liver homogenate a single signal was detected. Double staining of catalase and ICD2 in rat liver revealed co-localization of both enzymes in the same cytoplasmic granules. Immunoelectron microscopy revealed gold particles with antigenic sites of ICD2 present mainly in peroxisomes. The results clearly indicated that ICD2 is a peroxisomal enzyme in rat hepatocytes. ICD2 has been regarded as a cytosolic enzyme, probably because the enzyme easily leaks out of peroxisomes during homogenization. (J Histochem Cytochem 49:1123-1131, 2001)

Interphase detection of immunoglobulin heavy chain gene translocations with specific oncogene loci in 173 patients with B-cell lymphoma

To detect immunoglobulin heavy chain (IGH) gene translocations with specific oncogene loci, we established an interphase cytogenetic approach using double-color fluorescence in situ hybridization (DC-FISH), which we used to analyze 173 patients with B-cell lymphoma. DC-FISH using the IGH gene (14q32.3) in combination with c-MYC (8q24.1), BCL1 (11q13.3), BCL2 (18q21.3), BCL6 (3q27), and PAX-5 (9p13) gene probes detected IGH translocations in 70 (40.5%) of 173 patients. The partner genes involved in IGH translocations were identified in 56 (80%) of 70 patients, and fusion of the IGH gene with specific oncogenes was detected in 53 of 56 patients, particularly in interphase nuclei of 28 patients for whom cytogenetic analysis was not informative. The most common partner gene was BCL2 (19 patients; 27% of IGH translocation-positive patients), followed by BCL6 (16; 23%), BCL1 (11; 16%), c-MYC (7; 10%), and PAX-5 (2; 3%). These oncogenes were closely associated with subtypes of B-cell lymphoma. The other partners were 19q13 (BCL3), 6p25 (MUM1/IRF4), 1q36, and chromosome 8 identified in one patient each. Six of the nine patients with add(14)(q32) showed a BCL6/IGH translocation. Double translocations of the IGH gene were found in three patients; c-MYC+BCL1, c-MYC+BCL2, and c-MYC+BCL6 in each one. Interphase FISH using specific IGH-translocation probes is valuable for defining clinically meaningful subgroups of B-cell lymphoma.

A new recombinant human bone morphogenetic protein-2 carrier for bone regeneration

A gelatin sponge was formed by foaming and heat treating a gelatin solution, followed by coating the solid with poly(D,L-lactic-co-glycolic acid) to reinforce the gelatin framework. This sponge was tested for its suitability as a biodegradable porous, recombinant human bone morphogenetic protein (rhBMP)-2 carrier. Incorporation of rhBMP-2 into the sponge was closely related to its bulk density of gelatin sponge. The calcium content in the sponges, as assessed by an ectopic bone formation assay in rats, increased with the increasing sponge bulk density. Histologic and peripheral quantitative computed tomography analysis of implants in this ectopic assay system revealed cell growth throughout the carrier in 4 weeks after implantation regardless gelatin bulk density. The carrier containing rhBMP-2 maintained its three-dimensional structure after implantation; the carrier resisted collapse caused by soft tissue pressure during rapid bone formation as assessed by soft X-ray photographs. These results indicate that this newly developed sponge has excellent carrier characteristics to introduce rhBMP-2 into areas needed for bone regeneration.

The 70-kDa peroxisomal membrane protein (PMP70), an ATP-binding cassette transporter

The 70-kDa peroxisomal membrane protein (PMP70) is one of major components of peroxisomal membranes. In rodents, PMP70 is markedly induced by administration of hypolipidemic agents in parallel with peroxisome proliferation and the induction of peroxisomal fatty acid beta-oxidation enzymes. PMP70 is an ATP-binding cassette transporter, identified for the first time in intracellular membranes of eukaryotic cells. The authors' recent studies suggest that PMP70 is synthesized on free polysomes and posttranslationally inserted into peroxisomal membranes, and assembles as dimeric or oligomeric forms on peroxisomal membranes. PMP70 is suggested to be involved in metabolic transport of long-chain acyl-CoA across peroxisomal membranes.

Organization of projections from the medial agranular cortex to the superior colliculus in the rat: a study using anterograde and retrograde tracing methods

The organization of corticotectal projections from the medial agranular cortex (AGm), which has been considered to contain rat's frontal eye field, was examined using anterograde and retrograde tracing techniques. When biotinylated dextranamine (BDA) injections were made into the rostral part of the AGm, small numbers of BDA-labeled axons were found in the rostral two-thirds of the superior colliculus (SC) while some labeled axons were seen in the caudal one-third of the SC. These labeled axons were distributed mainly in the lateral part of the stratum griseum intermediale. On the other hand, after BDA injections into the caudal part of the AGm, moderate to dense plexuses of labeled axons were found in the rostral two-thirds of the SC while some labeled axons were seen in the caudal one-third of the SC. These labeled axons were distributed in the ventromedial and dorsolateral marginal zones of the stratum griseum intermediale as well as in the stratum griseum profundum. The corticotectal projections were largely uncrossed. After combined injections of BDA into the caudal part of the AGm on one side and cholera toxin B subunit (CTb) into the paramedian pontine reticular formation on the opposite side or into the interstitial nucleus of Cajal on the same side, the overlapping distributions of BDA-labeled axons and CTb-labeled neurons were found in the ventromedial marginal zone of the stratum griseum intermediale ipsilateral to the site of BDA injection. These results suggest that the caudal part of the AGm plays a more significant role in the oculomotor function than does the rostral part of the AGm.

[The minimal residual disease (MRD) in hematological malignancies]

Molecular genetic and cytoimmunological markers have been applied for the detection of minimal residual disease (MRD) in hematological malignancies. These markers include surface markers or rearranged T-cell receptor and immunoglobulin genes in the lymphoid malignancies and fused genes associated with chromosomal translocations such as BCR-ABL in t(9;22) or PML-RAR alpha in t(15;17) in myeloid malignancies. The expression of the WT1 gene is recognized as the universal tumor marker for a wide variety of hematological malignancies. Using these sensitive markers, a tumor cell in 10,000 to 1,000,000 normal cells can be detected. By examining a large number of patients, it has been shown that the MRD in the early phase of chemotherapy has a correlation with the prognosis of childhood ALL. Based on these observations, a new strategy of chemotherapy in which the post-remission therapy is modified based on the MRD results has begun. The amount of tumor cells contaminated in the autologous stem cell grafts in ALL patients might be related to the prognosis. The diagnosis of MRD will be used as an important routine examination in chemotherapy for leukemia/lymphoma patients.

The role of 15-lipoxygenase in disruption of the peroxisomal membrane and in programmed degradation of peroxisomes in normal rat liver

Our earlier electron microscopic observations revealed that prolonged exposure of glutaraldehyde-fixed rat liver sections to buffer solutions induced focal membrane disruptions of peroxisomes with catalase diffusion as shown cytochemically. Recently, it was suggested that 15-lipoxygenase (15-LOX) might be involved in natural degradation of membrane-bound organelles in reticulocytes by integrating into and permeabilizing the organelle membranes, leading to the release of matrix proteins. We have now investigated the localization of 15-LOX and its role in degradation of peroxisomal membranes in rat liver. Aldehyde-fixed liver slices were incubated in a medium that conserved the 15-LOX activity, consisting of 50 mM HEPES-KOH buffer (pH 7.4), 5 mM mercaptoethanol, 1 mM MgCl(2), 15 mM NaN(3), and 0.2 M sucrose, in presence or absence of 0.5-0.05 mM propyl gallate or esculetin, two inhibitors of 15-LOX. The exposure of aldehyde-fixed liver sections to this medium induced focal disruptions of peroxisome membranes and catalase diffusion around some but not all peroxisomes. This was significantly reduced by both 15-LOX inhibitors, propyl gallate and esculetin, with the latter being more effective. Double immunofluorescent staining for 15-LOX and catalase revealed that 15-LOX was co-localized with catalase in some but not all peroxisomes in rat hepatocytes. By postembedding immunoelectron microscopy, gold labeling was localized on membranes of some peroxisomes. These observations suggest that 15-LOX is involved in degradation of peroxisomal membranes and might have a physiological role in programmed degradation and turnover of peroxisomes in hepatocytes. (J Histochem Cytochem 49:613-621, 2001)

Cerebral blood flow velocity in two patients with neonatal cerebral infarction

Cerebral blood flow velocity was measured in the middle cerebral artery of two patients who exhibited unilateral neonatal cerebral infarction during the neonatal period. Doppler studies demonstrated increases in cerebral blood flow velocity but decreases in the resistance index on the affected side of the middle cerebral artery in the neonate who developed hemiplegia with cystic encephalomalacia, although the neonate with normal neurologic outcome exhibited symmetric cerebral blood flow velocity and resistance index. The asymmetry in cerebral blood flow velocity measurements of both middle cerebral arteries may be useful to evaluate the severity of brain damage and predict the neurodevelopmental prognosis of unilateral neonatal cerebral infarction.

Extensive proliferation of oligodendrocyte precursors in the parenchyma of the embryonic chick central nervous system

The proliferation of oligodendrocyte lineage cells in the chick embryo central nervous system (CNS) was examined by double-immunolabeling with a lineage marker monoclonal antibody (mAb) O4 or mAb O1 and 5-bromo-3'-deoxyuridine (BrdU). In all regions examined, the first O4-positive (O4+) cells appeared in restricted regions of the ventricular zone (VZ), regarded as a site of oligodendrocyte origin. Within the O4+ focus, less than 20% of the O4+ cells incorporated BrdU. In contrast, O4+ cells in the parenchyma were mitotically active; for example, 40-50% of early O4+ cells were labeled with BrdU. Some of these were unipolar in shape, indicative of migratory precursor cells. The frequency of O4+/BrdU+ cell appearance decreased to less than 20% with further development. O1+ oligodendrocytes were largely mitotically inactive, with only approximately 5% of O1+ cells incorporating BrdU. These results clearly demonstrated that the VZ generates relatively few precursor cells and that these oligodendrocyte precursors actively generate their cohort in the parenchyma of the CNS.

Signal through gp130 activated by soluble interleukin (IL)-6 receptor (R) and IL-6 or IL-6R/IL-6 fusion protein enhances ex vivo expansion of human peripheral blood-derived hematopoietic progenitors

This study was designed to investigate the effects of a combination of soluble interleukin (sIL)-6 receptor (R) and IL-6 on the ex vivo expansion of human peripheral blood (PB)-derived hematopoietic progenitor cells in a short-term serum-free liquid suspension culture system, using PB-derived CD34(+)IL-6R(+/-) cells as a target. In combination with stem cell factor (SCF), IL-3, and sIL-6R/IL-6, the expansion efficiency (EE) for granulocyte/macrophage colony-forming unit (CFU-GM) reached a peak level on day 10 of incubation. On the other hand, the EE for erythroid burst (BFU-E) and mixed colony-forming unit (CFU-Mix) reached a peak level on day 7 of incubation. Among the cytokine combinations tested, SCF + IL-3 + sIL-6R/IL-6 + flt3 ligand (FL) most effectively expanded CFU-GM and CFU-Mix. The maximum EEs for CFU-GM and CFU-Mix were 208-fold and 42-fold, respectively. While the EE for BFU-E was 70-90-fold in the presence of SCF + IL-3 + sIL-6R/IL-6, FL significantly augmented the EE for CFU-GM and CFU-Mix. In contrast, thrombopoietin (TPO) significantly augmented the EE for CFU-Mix. Interestingly, in combination with IL-3 and SCF, newly generated IL-6R/IL-6 fusion protein (FP) expanded PB-derived BFU-E and CFU-Mix twice more effectively than a combination of sIL-6R and IL-6. These results demonstrated that human PB-derived committed progenitors were effectively expanded in vitro using sIL-6R/IL-6 or FP, in combination with IL-3, SCF and/or FL or TPO, and that FP may transduce a stronger intracellular signal than a combination of sIL-6R and IL-6.

Phrenic motoneurons receive monosynaptic inputs from the Kölliker-Fuse nucleus: a light- and electron-microscopic study in the rat

The parabrachial complex, which plays an important role in respiratory regulation, has been reported to send projection fibers to the phrenic nucleus, but the synaptic organization between the parabrachial fibers and the phrenic motoneurons has not been examined. Using anterograde and retrograde tracing methods, we found in the rat that the parabrachial fibers originating mainly from the Kölliker-Fuse nucleus (KF) terminated not only within the phrenic nucleus but also on the radial dendritic bundles of the phrenic motoneurons. It was further revealed that the KF fibers made asymmetrical synapses predominantly with dendrites and partly with somata of the phrenic motoneurons. These data suggest that output signals from the KF may exert excitatory influence directly upon the phrenic motoneurons.

The effects of KNK437, a novel inhibitor of heat shock protein synthesis, on the acquisition of thermotolerance in a murine transplantable tumor in vivo

A newly synthesized reagent, KNK437, has been found specifically to inhibit the synthesis of heat shock proteins in vitro. In this study, we investigated the effects of KNK437 on the synthesis of heat shock proteins and the induction of thermotolerance in transplantable tumors in vivo. SCC VII cells were grown in vivo and transplanted into C3H/He mice. The concentrations of KNK437 in the tumors and the sera of the mice were examined by high-performance liquid chromatography. Hsp72 synthesis was examined by Western immunoblot analysis. The response to hyperthermia was evaluated in terms of the delay in tumor growth. KNK437 had low toxicity in vivo. The concentration of KNK437 in the tumors gradually increased and reached a peak 6 h after i.p. injection. Hsp72 were synthesized 8 h after hyperthermia at 44 degrees C for 10 min, and their synthesis was inhibited by administration of KNK437 6 h before hyperthermia. At a concentration of 200 mg/kg, KNK437 alone showed no antitumor effects and did not increase the thermosensitivity of nontolerant tumors. The same dose of KNK437 enhanced the antitumor effects of fractionated heat treatment at 44 degrees C in a synergistic manner. This study strongly suggests the inhibition of thermotolerance via the inhibition of HSP72 in vivo. The inhibition of thermotolerance by KNK437 may help to improve the efficacy of clinical fractionated hyperthermia.

Proteasome-dependent degradation of cytosolic chaperonin CCT

The chaperonin containing t-complex polypeptide 1 (CCT) is a heterooligomeric molecular chaperone that assists in the folding of actin, tubulin, and other cytosolic proteins. We show here that degradation of CCT in mammalian cells is inhibited by a proteasome-specific inhibitor, lactacystin. When CCT synthesis was inhibited by growth arrest of cells, the decrease in CCT levels was much slower in the presence of lactacystin than in its absence. Pulse-chase experiments indicated that degradation of CCT is inhibited 2- to 2.5-fold by addition of lactacystin. In addition, CCT degradation rate in ts85 cells that produce thermolabile ubiquitin-activating enzyme E1 was reduced 3-fold at the nonpermissive temperature compared to the degradation at the permissive temperature. These results indicate that the ubiquitin-proteasome system is involved in CCT degradation.

Aggregate formation and degradation of overexpressed wild-type and mutant urate oxidase proteins. Quality control of organelle-destined proteins by the endoplasmic reticulum

To analyze the cellular response caused by the overexpression of proteins in subcellular compartments, we constructed four expression clones encoding wild-type peroxisomal urate oxidase (UO), truncated UO lacking the peroxisomal targeting signal (UOdC), and chimeric UOs with a mitochondrial targeting signal (MTS) at the N-terminus of UOdC (MUOdC) or UO (MUO). After transfection, we examined COS-1 and HEK293 cells by immunofluorescence and immunoelectron microscopy, transmission electron microscopy, and pulse-chase experiments. The overexpressed UO and UOdC formed large electron-dense aggregates with no limiting membrane in both the cytoplasm and the nucleus. The UO aggregates exhibited the crystalloid structure quite similar to that of rat liver peroxisomal cores, whereas the UOdC aggregates formed a loose mass consisting of small dense substructures. The overexpressed MUOdC and MUO, on the other hand, formed other types of aggregates which were distributed in the cytoplasm. They consisted of tubular and circular membrane structures, which were morphologically confirmed to be derived from the endoplasmic reticulum (ER). No immunolabeling signals for MUOdC and MUO were present free in the cytoplasm and most of them were associated with membrane structures, suggesting that overexpressed UO containing the MTS attached to the ER membranes soon after synthesis and segregated from the cytosolic compartment. All the UO aggregates were stained for ubiquitin antigen. Pulse-chase experiments in combination with proteasome inhibitors suggested that proteasomes did not contribute to the degradation of these products.

Rare alteration of genomic structure or expression of the DPC4 gene in myelogenous leukemias

We examined homozygous deletion, point mutation and expression of DPC4 gene, a recently isolated candidate pancreatic tumor suppressor gene, in 53 patients with myelogenous leukemias and 5 cell lines. The patients consisted of 34 cases of chronic myelogenous leukemia including 22 in the chronic phase, 3 in the accelerated phase, and 9 in blastic crisis, and 19 with acute myelogenous leukemia including 9 at the initial presentation and 10 at relapse. Polymerase chain reaction (PCR)-based deletion analysis for DPC4 exon 8 and PCR-single strand conformation polymorphism study for the entire coding region were carried out. Homozygous deletion or subtle mutation was not detected in any of the samples examined. However, 3 patients with various clinical phases showed a decrease of DPC4 expression. These results suggest that DPC4 alteration is not a crucial event in the development or the progression of myelogenous leukemias.