Role of autoantibodies against tubular brush border antigens in tubulointerstitial nephritis associated with Heymann nephritis

Previous studies have shown that a rat experimental model of membranous nephropathy (Heymann nephritis) is often associated with tubulointerstitial changes. Although antibody-dependent tubular injuries have been proposed in this model, precise mechanisms have been ill-defined. In the present report, we established a model of acute tubulointerstitial nephritis (TIN) by injecting puromycin aminonucleoside (PAN) to Wistar rats which had been immunized with tubular antigens (Tub-Ag). In this model, TIN developed 4 weeks after Tub-Ag immunization when rats had a high titer of circulating anti-Tub-Ag antibodies and began to excrete massive proteinuria. Deposits of immunoglobulins along tubular brush borders were also demonstrated. Rats receiving either Tub-Ag or PAN alone failed to develop TIN during this relatively acute phase. These results suggest that anti-Tub-Ag antibodies excreted into the urine play a role in developing TIN in this model.

[Role of angiogenesis in lung cancer and its metastases]

Although the modalities for the diagnosis and treatment of lung cancer patients have been improved, the prognosis of the patients is still poor. However, new technology and advances in the fields of molecular and cell biology have allowed investigators to explore the mechanisms of growth, invasion, and metastasis of lung cancer. In fact, it has been reported that angiogenesis is necessary for the growth and metastasis of lung cancer, thus indicating the therapeutic target. Moreover, VEGF has been shown to be essential not only for angiogenesis but also for the formation of pleural effusions produced by lung cancer via induction of vascular hyperpermeability. Here, we review recent findings on angiogenesis in lung cancer, and the possibility of the clinical use of antiangiogenic agents for lung cancer patients.

The effects of angiotensin metabolites on the regulation of coagulation and fibrinolysis in cultured rat aortic endothelial cells

Not only angiotensin II (Ang II) but also other angiotensin metabolites such as angiotensin I (Ang I), angiotensin III (Ang III), angiotensin IV, or angiotensin 1-7 have recently been reported to have various activities. Few data, however, are available on the regulation of thrombus formation. In this study, we investigated the effects of angiotensin metabolites on the mRNA expression of tissue factor (TF), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1), and tissue type plasminogen activator (TPA) in cultured rat aortic endothelial cells. None of the used angiotensin metabolites altered TFPI or TPA mRNA expression levels. Ang I, Ang II, and Ang III made TF and PAI-1 mRNA inductions which were inhibited by an selective antagonist of angiotensin II type 1 receptors. These metabolites made TF predominant to TFPI or PAI-1 to TPA, and could render endothelial cells thrombogenic.

Synthesis of the optical isomers of 4-[1-(4-tert-butylphenyl)-2-oxo- pyrrolidine-4-yl]methyloxybenzoic acid (S-2) and their biological evaluation as antilipidemic agent

The enantiomers of (+/-)-4-[1-(4-tert-butylphenyl)-2-oxo-pyrrolidine- 4-yl]methyloxybenzoic acid (S-2), a new antilipidemic agent having dual action on the plasma triglyceride (TG) and cholesterol (Cho) lowering effects, were prepared via separation by Chiralcel OJ column chromatography of their methyl ester and also by the same method as the described racemate's synthesis from optically active 1-(4-tert-butylphenyl)-2-oxo-pyrrolidine-4-carboxylic acid respectively. These optically active carboxylic acids were prepared by the resolution of diastereomeric N-[(S)-(-)-[4-methyl-(alpha-methyl)benzyl]]-1-(4-tert-butylphenyl)-2-oxo - pyrrolidine-4-carboxyamide using silica gel column chromatography, followed by deamination with N2O4. The absolute configurations for the enantiomers of S-2 were indirectly determined using X-ray analysis of the 4-bromo-2-fluorobenzamide of the (+)-4-[1-(4-tert-butylphenyl)-2- oxo-pyrrolidine-4-yl]-methyloxybenzoic acid. S-2 and its enantiomers showed an essentially equipotent activity on the fatty acid- and sterol-biosynthesis inhibition in vitro. On the other hand, in the in vivo activity, (S)-(+)-4-[1-(4-tert-butylphenyl)-2-oxo-pyrrolidine- 4-yl]methyloxybenzoic acid (S-2E) was superior in the lowering abilities of the plasma TG and phospholipid(PL) and was chosen as a candidate for a novel antilipidemic agent. The difference in the in vivo activity among S-2 and its enantiomers was explained from the pharmacokinetics after administration p.o.

Vascular endothelial growth factor levels and induction of permeability in malignant pleural effusions

Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis and vascular permeability. We hypothesized that malignant pleural effusions may contain high levels of VEGF protein as well as other cytokines implicated in these processes. Pleural effusions cytologically proven to be malignant were collected from 39 patients with various types of cancer, and VEGF, interleukin-8, and angiogenin levels in the effusions were determined by immunoassay. Negative controls were nonmalignant ascites and serum samples from healthy individuals. VEGF levels were significantly higher than those of control samples in pleural effusions secondary to breast, mesothelioma, and non-small cell lung cancer and when all malignant pleural effusion samples were pooled. Neither interleukin-8 nor angiogenin levels were elevated in malignant pleural effusions relative to the control samples. Vascular permeability, which was measured by using the Miles assay in nude mice, was increased proportionately with VEGF levels in the malignant pleural effusions; this increase in permeability induced by injection of recombinant VEGF or the malignant effusions was reduced by pretreating the mice with a VEGF receptor antibody.

Apoptosis induction of human lung cancer cell line in multicellular heterospheroids with humanized antiganglioside GM2 monoclonal antibody

The chimeric antiganglioside GM2 monoclonal antibody (MAb) KM966, which showed high effector functions such as complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity (ADCC), potently suppressed growth and metastases of GM2-positive human cancer cells inoculated into mice. To further improve the therapeutic efficacy of the anti-GM2 MAb in humans, we constructed a humanized anti-GM2 MAb, KM8969. The humanized KM8969 was more efficient in supporting ADCC against GM2-positive human cancer cell lines than the chimeric KM966, whereas complement-dependent cytotoxicity was slightly reduced in the humanized KM8969. In addition, the humanized KM8969 was shown to exert potent ADCC mediated by both lymphocytes and monocytes. To investigate the effect of the humanized KM8969 on the biological function of GM2 in the condition physiologically mimicking formation and growth of cancer masses, the heterospheroids composed of normal human dermal fibroblasts and GM2-positive human lung cancer cells were developed. Interestingly, the humanized KM8969 gave rise to growth inhibition of heterospheroids without dependence of the effector functions. Morphological and immunocytochemical analysis suggested that the inhibitory effect was due to the apoptosis of GM2-positive cancer cells in the heterospheroids. The result indicates that GM2 captured by the antibody on the cell surface loses its physiological function that plays a critical role in maintaining the three-dimensional growth of cancer cells in contact with its own cells or other type of cells in a microenvironment. The humanized KM8969, which can destroy the cancer cells via blocking functional GM2 on the cell surface as well as the effector functions, would have extraordinary potential in human cancer therapy.

Successful low-dose cytosine arabinoside treatment in a patient with acute leukemia from idiopathic myelofibrosis

We report a 63-year-old male with acute leukemia developed from idiopathic myelofibrosis. Cytogenetic analysis revealed chromosomal abnormalities; 46,XY,t(3;21)(q21;q22) del(20q). Intensive chemotherapies [combination of adriamycine/vincristine/prednisolone, or idarubicine/cytosine arabinoside (Ara-C)] were unsuccessful. The patient was then treated with continuous intravenous low-dose Ara-C because of his poor physical condition and showed marked hematological improvement. Leukemic cells disappeared from the peripheral blood and the segmented neutrophil count recovered. The dysplastic morphology observed in the segmented neutrophils suggests that the recovery of the neutrophils has resulted mainly from the differentiation activity of Ara-C.

Associations between different status of myocardial ischemia and ischemia-related negative or positive epicardial U-waves: observations during coronary angioplasty

This study examined the relationships between the polarity of the U wave on intracoronary electrocardiogram (ECG) and the status of myocardial ischemia during angioplasty. The ECG features of ischemia-related U waves were also evaluated. Among 63 patients with intracoronary ECGs adequate for analysis of U waves, there were 26 patients showing a change of the U wave to a negative direction and 18 patients showing a change to a positive direction from baseline to coronary occlusion. Among these patients, 10 of the former showed a distinct change in polarity of the U wave from positive to negative (group A), and 7 of the latter patients showed the opposite change (group B). Patients in group B had a higher incidence of prior myocardial infarction (86% vs 30%; P < .05), presence of an abnormal Q wave on intracoronary ECG (71% vs 20%; P < .05), poor wall motion in the angioplasty-related area (100% vs 30%; P < .01), and lower left ventricular ejection fraction (55.7% +/-8.1% vs 66.6% +/- 4.5%; P < .01) than patients in group A. The remaining patients (other than groups A and B) showing U wave change in a negative (n = 16) or positive (n = 11) direction presented with similar features to those in groups A or B, respectively. The ECG features of several types of ischemia-related U wave were determined by analysis of intracoronary ECG obtained from the patients in groups A and B. In group A, the Bazett-corrected Q (positive U) interval measured at baseline (myocardial state; near normal) was significantly shorter than the Q-(negative U) interval measured during coronary occlusion (acute ischemia) (0.518 +/- 0.031 s vs 0.579 +/- 0.046 s; P < .01). In group B, the Q-(negative U) interval measured at baseline (chronic ischemia) was longer than the Q-(positive U) interval measured during angioplasty (acute-on-chronic ischemia) (0.582 +/- 0.034 s vs 0.501 +/- 0.027 s; P < .001). Thus, intracoronary ECG recorded during angioplasty in the present study revealed physiologic U wave, two types ("acute" and "chronic") of ischemia-related negative and one type ("pseudonormal") of ischemia-related positive U waves, each of which appeared in a different status of myocardial ischemia and possessed characteristic ECG features in its appearance.

[A case of recurrent ampullary carcinoma of the papilla of Vater, in which a complete response was induced by combination therapy using radiotherapy and oral chemotherapy employing UFT and cyclophosphamide]

A 38-year-old male patient underwent a pylorus-preserving pancreatoduodenectomy for an ampullary carcinoma of the papilla of Vater. One year after surgery a regular examination with CT and an echogram revealed a solitary recurrent tumor at a lymph node near the superior mesenteric artery. He was treated with radiotherapy at a total of 60 Gy and chemotherapy with UFT at 300 mg/day daily and oral administration of cyclophosphamide at 50 mg/day every other day. Four months after the initiation of the therapy the tumor had completely disappeared and the objective response was evaluated as a CR. The patients is now disease-free and continues to be treated with oral UFT and cyclophosphamide on an outpatient basis.

Bronchocentric granulomatosis due to Aspergillus terreus in an immunocompetent and non-asthmatic woman

This is the first report of bronchocentric granulomatosis due to Aspergillus terreus in a healthy and non-asthmatic 74-year-old Japanese woman. Following identification of the fungus, oral itraconazole therapy was begun after intrabronchial infusion of amphotericin B. No recurrence has occurred after treatment for 24 months. We should consider the possibility of bronchocentric granulomatosis including Aspergillus terreus, when an intrabronchial lesion is found even in a healthy and non-asthmatic person. Oral itraconazole after intrabronchial infusion of amphotericin B seems to be effective in such cases.

Varicella-zoster virus-specific cellular immunity in subjects given acyclovir after household chickenpox exposure

The time course of primary cell-mediated immune responses to varicella-zoster virus (VZV) among persons receiving acyclovir prophylaxis after exposure to chickenpox has not been well defined. Fifteen children who had household exposure to varicella received prophylactic acyclovir (40 mg/kg/day for 7-14 days after exposure) and were studied for development of both antibody and cell-mediated immunity (CMI) to VZV. Twelve developed antibodies and/or CMI; 10 had no symptoms and 2 manifested mild varicella. Two were already immune to varicella and had booster immune responses. One was not infected and subsequently developed full-blown varicella. Although acyclovir given after exposure to VZV is highly effective and does not appear to attenuate the immune response, it remains necessary to confirm whether, in the absence of clinical varicella, persons acquire specific immunity.

Formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine under anaerobic conditions by reductively activated nitro 5-deazaflavin derivatives

Electrolytically reduced 6- and 8-nitro-5-deazaflavin derivatives have been found to interact to react specifically with guanine base by means of cyclic voltammetry. Electrolytic reductions of 6- and 8-nitro-5-deazaflavin derivatives in the presence of the 2'-deoxyguanosine under anaerobic conditions resulted in prominent formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine.

Oral administration of the immunomodulator JBT-3002 induces endogenous interleukin 15 in intestinal macrophages for protection against irinotecan-mediated destruction of intestinal epithelium

We recently reported that p.o. administration of the new synthetic bacterial lipopeptide JBT-3002 can protect mice from irinotecan (CPT-11)-induced intestinal injury, but the mechanism was not known. Because interleukin-15 (IL-15) is associated with maintenance of intestinal epithelial cell integrity, we examined whether p.o. administration of JBT-3002 elevates expression of this monocyte-derived cytokine. Four daily i.p. injections of 100 mg/kg CPT-11 were effective against liver metastases produced by CT-26 murine colon cancer cells, but severe damage to the intestinal epithelium and early death of the mice also resulted. Three consecutive daily p.o. doses of JBT-3002 prior to i.p. injection of irinotecan prevented the undesirable side effects of irinotecan without reducing its ability to eradicate liver metastases. Immunohistochemical analyses of the intestines of mice treated with JBT-3002 and CPT-11 demonstrated an increase in the number of dividing cells in the crypts and enhanced expression of IL-15 in lamina propria cells; the increase correlated with increased expression of the IL-15 gene as determined by semiquantitative reverse transcriptase-PCR. In vitro studies demonstrated that JBT-3002 induced expression of IL-15 in peritoneal macrophages but not in normal intestinal epithelial cells (IEC-6). Moreover, the presence of IL-15 decreased irinotecan-mediated cytotoxicity of IEC-6 epithelial cells. These data show that the p.o. administration of JBT-3002 induces expression of IL-15 by macrophages in the lamina propria, which can prevent irinotecan-induced injury to the intestinal mucosa.

[Carcinomatous pericarditis monitored by pulsed Doppler echocardiography of superior vena cava: hemodynamics from pericardial effusion to pericardial solid invasion]

We utilized pulsed Doppler echocardiography to monitor changes in a patient with carcinomatous pericarditis, from pericardial effusion with cardiac tamponade to pericardial solid invasion. Characteristic changes in superior vena cava (SVC) pulsed Doppler flow patterns were observed after invasion of the pericardium. SVC pulsed Doppler flow patterns are a useful aid in differentiating between solid invasions and recurrent pericardial effusion with pericardial thickening: this diagnostic capability is not readily available with computed tomography.

Monoclonal antibodies specific to carbohydrates of Echinococcus multilocularis

To investigate the complexity of epitopes presented on Echinococcus multilocularis (E.m.) metacestode carbohydrates, a panel of monoclonal antibodies (MoAbs) was generated and characterized. Thirty of the clones were obtained and classified into three types (types I to III) based on Western blotting (WB) and dot-ELISA. One MoAb (type I) appeared to react with one of the carbohydrate antigens (C-antigens) located at 30-35 kDa, and was the most effective diagnostic antigen for human alveolar hydatid disease (AHD) in Hokkaido, Japan. The second group (15 clones) of MoAb (type II) reacted with another C-antigen; one which also induced antibody response in AHD patients. The third group (14 clones) of MoAb (type III) reacted with other C-antigens both in ELISA and dot-ELISA, but did not react in WB. Cross-reaction to the antigens of Echinococcus granulosus was faintly observed in only the type I-MoAb by dot-ELISA. In the immunohistological studies, all of the MoAbs reacted strongly with the laminated layer though not with protoscoleces in metacestode tissue prepared from experimentally infected cotton rats. Tissue sections treated with sodium periodate lost their immunoreactivity, suggesting that these MoAbs recognized carbohydrate epitopes of the E.m. metacestode.

High extracellular calcium inhibits osteoclast-like cell formation by directly acting on the calcium-sensing receptor existing in osteoclast precursor cells

Although it has recently been suggested that high extracellular calcium ([Ca(2+)](e)) inhibits osteoclast function via a calcium-sensing receptor (CaSR) in mature osteoclasts, the role of CaSR in the regulation of osteoclast formation remains unknown. The present study was performed to investigate whether osteoclast precursor cells possess CaSR and to clarify the possible role of CaSR in the regulation of osteoclast formation. Immunocytochemistry detected CaSR in osteoclast precursor cells derived from spleen cells as well as in osteoblastic MC3T3-E1 cells. The use of reverse-transcription polymerase chain reaction (RT-PCR) with CaSR-specific primers, followed by nucleotide sequencing of the amplified products, also identified CaSR transcripts in osteoclast precursor cells derived from spleen cells as well as in MC3T3-E1 cells. High [Ca(2+)](e) (3 to 5 mM) concentration dependently inhibited 1,25(OH)2D3- or human parathyroid hormone (hPTH) (1-34)-induced osteoclast-like cell (Ocl) formation from osteoclast precursor cells derived from spleen cells. Further, the CaSR agonist neomycin also concentration dependently inhibited 1,25(OH)2D3- or hPTH(1-34)-induced Ocl formation. Moreover, a calcimimetic which mimics or potentiates the effects of [Ca(2+)](e) at the CaSR NPS R-467 (1-100 microM) concentration dependently inhibited Ocl formation stimulated by 1,25(OH)2D3 or hPTH(1-34). These findings first demonstrated that osteoclast precursor cells possess CaSR very similar, if not identical, to those in the parathyroid and kidney. Furthermore, the CaSR in osteoclast precursor cells could play a key role in regulating Ocl formation by sensing local changes in [Ca(2+)](e) at the resorptive sites.

Combined therapy with anti-P-glycoprotein antibody and macrophage colony-stimulating factor gene transduction for multiorgan metastases of multidrug-resistant human small cell lung cancer in NK cell-depleted SCID mice

Our aim was to determine the antimetastatic potential of anti-P-glycoprotein (P-gp) antibodies (Abs) against multidrug-resistant (MDR) human small cell lung cancer (SCLC) cells expressing P-gp. Human SCLC cells H69 (P-gp negative) and its etoposide-resistant variant H69/YP (P-gp positive) were used. H69 and H69/VP cells injected i.v. metastasized to the liver, kidneys and systemic lymph nodes of NK cell-depleted severe combined immunodeficient (SCID) mice. H69/VP cells, but not H69 cells, were resistant to treatments with vindesine. Treatment with mouse-human chimeric anti-P-gp Ab (MH162) and its mouse counterpart (MRK-16) reduced metastasis of H69/VP cells in various organs and prolonged the survival of tumor-bearing mice, although they were less effective if injected at late times (after 28 days). Treatment with another mouse anti-Pgp Ab, MRK-17, was effective only against liver metastasis. MH162 and MRK-16 efficiently induced Ab-dependent cellular cytotoxicity (ADCC) by peritoneal macrophages against H69/VP cells in vitro, but MRK-17 was less effective, in accordance with their in vivo antimetastatic potential. Gene transfection of macrophage colony-stimulating factor (M-CSF) into H69/VP cells to augment macrophage-mediated ADCC resulted in inhibition of metastasis to the liver and lymph nodes, but not kidneys. Combined treatment with a low dose of MRK-16 completely cured metastasis of M-CSF transfectant, but not of the mock transfectant. Our findings suggest that while anti-P-gp Abs had antimetastatic potential against SCLC cells expressing P-gp, combined treatment with M-CSF gene transduction to augment the therapeutic efficacy of anti-P-gp Abs may be beneficial for eradicating metastatic MDR SCLC in humans.

Opioid receptor agonistic characteristics of mitragynine pseudoindoxyl in comparison with mitragynine derived from Thai medicinal plant Mitragyna speciosa

We have previously elucidated the opiate-like action of mitragynine, an active principle isolated from the Thai medicinal plant Mitragyna speciosa. In the present study, effects of the related compound, mitragynine pseudoindoxyl on electrically stimulated contraction in guinea pig ileum and mouse vas deferens, and on its binding affinity in the guinea pig brain membranes were studied. Mitragynine pseudoindoxyl inhibited the electrically stimulated ileum and mouse vas deferens contractions in a concentration-dependent manner. In the ileum, the effective concentration is in an nM order, being nearly equivalent to reported concentrations of the micro-opioid receptor agonist [D-Ala2, Met-Phe4, Gly-ol5] enkephalin (DAMGO), and is 100- and 20-fold smaller than those of mitragynine and morphine, respectively. In the vas deferens, it is 35-fold smaller than that of morphine. The inhibitory action of mitragynine pseudoindoxyl in the ileum was antagonized by the non-selective opioid receptor antagonist naloxone and the micro-receptor antagonist naloxonazine. It was also antagonized by the delta-receptor antagonist naltrindole in the vas deferens. Mitragynine pseudoindoxyl showed a similar binding affinity to DAMGO and naltrindole at micro- and delta-receptors, respectively. However, the affinity at kappa-receptors was negligible. The present study demonstrates that mitragynine pseudoindoxyl, a novel alkaloid structurally different from other opioid agonists, acts on opioid receptors, leading to a potent inhibition of electrically stimulated contraction in the ileum through the micro-receptors and in mouse vas deferens through delta-receptors.

Heterogeneity of multiorgan metastases of human lung cancer cells genetically engineered to produce cytokines and reversal using chimeric monoclonal antibodies in natural killer cell-depleted severe combined immunodeficient mice

Lung cancer is a major cause of cancer deaths, most of which can be attributed to distant multiorgan metastases. To examine the cellular and molecular mechanisms of lung cancer metastasis to distant organs, we have established novel models of human lung cancer (small cell and non-small cell lung cancer) metastasis in natural killer cell-depleted severe combined immunodeficient (SCID) mice. We investigated whether local production of the cytokines responsible for regulation of macrophage function at tumor growth sites affects the pattern of lung cancer metastasis in distant organs. Several lung cancer cell lines were genetically engineered to produce human macrophage colony-stimulating factor (M-CSF) and monocyte chemoattractant protein-1 (MCP-1), and their metastatic potentials were assessed. Interestingly, M-CSF gene transduction had an antimetastatic effect for the liver and lymph nodes, but not the kidneys. In contrast, MCP-1 gene-modified lung cancer cells and their parent cells had identical metastatic potentials. These findings indicate a possible role for cytokines and suggest that lung cancer has metastatic heterogeneity. Examining ways of controlling human lung cancer metastases, we investigated the antimetastatic effect of chimeric monoclonal antibodies (MAbs) against P-glycoprotein and ganglioside GM2 (MH162 and KM966, respectively). Both MAbs, when given on days 2 and 7, inhibited the development of distant metastases of lung cancer in a dose-dependent fashion. Combined use of anti-P-glycoprotein MAb with M-CSF or MCP-1 gene transduction caused complete inhibition of metastasis of H69/VP cells. The antimetastatic effect of these MAbs in vivo was mainly due to an antibody-dependent cell-mediated cytotoxicity reaction mediated by mouse macrophages. These findings suggest that the mouse-human chimeric MAb in combination with cytokine gene transduction may be useful for the eradication of lung cancer metastases in humans.

Purification and characterization of thermostable aspartase from Bacillus sp. YM55-1

A thermostable aspartase was purified from a thermophile Bacillus sp. YM55-1 and characterized in terms of activity and stability. The enzyme was isolated by a 5-min heat treatment at 75 degrees C in the presence of 11% (w/v) ammonium sulfate and 100 mM aspartate, followed by Q-Sepharose anion-exchange and AF-Red Toyopearl chromatographies. The native molecular weight of aspartase determined by gel filtration was about 200,000, and this enzyme was composed of four identical monomers with molecular weights of 51,000 determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Unlike Escherichia coli aspartase, the enzyme was not activated by the presence of magnesium ion at alkaline pH. At the optimum pH, the Km and Vmax were 28.5 mM and 700 units/mg at 30 degrees C and 32.0 mM and 2200 units/mg at 55 degrees C, respectively. The specific activity was four and three times higher than those of E. coli and Pseudomonas fluorescens enzymes at 30 degrees C, respectively. Eighty percent of the activity was retained after a 60-min incubation at 55 degrees C, and the enzyme was also resistant to chemical denaturants; 80% of the initial specific activity was detected in assay mixtures containing 1.0 M guanidine hydrochloride. The purified enzyme shared a high sequence homology in the N-terminal region with aspartases from other organisms.

Substrate recognition by Ca2+/Calmodulin-dependent protein kinase kinase. Role of the arg-pro-rich insert domain

Mammalian Ca2+/CaM-dependent protein kinase kinase (CaM-KK) has been identified and cloned as an activator for two kinases, CaM kinase I (CaM-KI) and CaM kinase IV (CaM-KIV), and a recent report (Yano, S., Tokumitsu, H., and Soderling, T. R. (1998) Nature 396, 584-587) demonstrates that CaM-KK can also activate and phosphorylate protein kinase B (PKB). In this study, we identify a CaM-KK from Caenorhabditis elegans, and comparison of its sequence with the mammalian CaM-KK alpha and beta shows a unique Arg-Pro (RP)-rich insert in their catalytic domains relative to other protein kinases. Deletion of the RP-domain resulted in complete loss of CaM-KIV activation activity and physical interaction of CaM-KK with glutathione S-transferase-CaM-KIV (T196A). However, CaM-KK autophosphorylation and phosphorylation of a synthetic peptide substrate were normal in the RP-domain mutant. Site-directed mutagenesis of three conserved Arg in the RP- domain of CaM-KK confirmed that these positive charges are important for CaM-KIV activation. The RP- domain deletion mutant also failed to fully activate and phosphorylate CaM-KI, but this mutant was indistinguishable from wild-type CaM-KK for the phosphorylation and activation of PKB. These results indicate that the RP-domain in CaM-KK is critical for recognition of downstream CaM-kinases but not for its catalytic activity (i.e. autophosphorylation) and PKB activation.

Management of acute metabolic decompensation in maple syrup urine disease: a multi-center study

BACKGROUND

Therapeutic modalities in acute metabolic decompensation in maple syrup urine disease (MSUD) are variable, and outcomes of each therapeutic measure have been known only individually. Factors that affect neurological outcome are not clear.

METHODS

A questionnaire was sent throughout Japan to each pediatrician treating any of the 42 MSUD patients.

RESULTS

Necessary information was available for 13 patients through the questionnaire, and through a publication for one patient. In nine of the 14 patients episodes of metabolic decompensation developed in the neonatal period. In the other five, the onset of disease was delayed until infancy or later. In the nine patients with neonatal onset, a pretreatment level of plasma leucine greater than 40 mg/100 mL or a duration of altered level of alertness longer than 10 days was associated with a poor neurological outcome. The therapeutic measures employed included intravenous infusion of glucose and electrolyte solution or hypertonic glucose and electrolyte solution, exchange transfusion, peritoneal dialysis, a large dose of thiamine and intravenous hyperalimentation. All patients had survived the episodes and were alive at the time of the survey. Five of the nine patients with neonatal onset have developed neurological sequelae to varying degrees. Episodes of metabolic decompensation in infancy or thereafter did not affect, or only minimally affected, the neurological outcome.

CONCLUSION

Therapeutic goals to improve neurological outcome are to shorten the duration of the altered level of consciousness, and to minimize the peak plasma leucine level as much as possible.

Intrabronchial Aspergillus nidulans infection in an immunocompetent man

We describe the first report of intrabronchial Aspergillus nidulans infection in an immunocompetent patient, which fit the description of bronchocentric granulomatosis. The patient had a history of accidental aspiration of light grade oil. Fiberoptic bronchoscopy revealed that the right B4aii alpha was obstructed. Endobronchial biopsy specimens contained fungal hyphae. The fungus was confirmed to be Aspergillus nidulans by culture. We suspected that aspiration of light grade oil had injured the bronchial mucosa, after which airborne Aspergillus nidulans had entered the lesion and multiplied. Intrabronchial fungal infection can occur in a healthy person without immunologic abnormalities, if a bronchial lesion provides an entry portal.