Oligogalacturonic acid and chitosan reduce stomatal aperture by inducing the evolution of reactive oxygen species from guard cells of tomato and Commelina communis

Stomatal opening provides access to inner leaf tissues for many plant pathogens, so narrowing stomatal apertures may be advantageous for plant defense. We investigated how guard cells respond to elicitors that can be generated from cell walls of plants or pathogens during pathogen infection. The effect of oligogalacturonic acid (OGA), a degradation product of the plant cell wall, and chitosan (beta-1,4-linked glucosamine), a component of the fungal cell wall, on stomatal movements were examined in leaf epidermis of tomato (Lycopersicon esculentum L.) and Commelina communis L. These elicitors reduced the size of the stomatal aperture. OGA not only inhibited light-induced stomatal opening, but also accelerated stomatal closing in both species; chitosan inhibited light-induced stomatal opening in tomato epidermis. The effects of OGA and chitosan were suppressed when EGTA, catalase, or ascorbic acid was present in the medium, suggesting that Ca(2+) and H(2)O(2) mediate the elicitor-induced decrease of stomatal apertures. We show that the H(2)O(2) that is involved in this process is produced by guard cells in response to elicitors. Our results suggest that guard cells infected by pathogens may close their stomata via a pathway involving H(2)O(2) production, thus interfering with the continuous invasion of pathogens through the stomatal pores.

Fetal mouse selenophosphate synthetase 2 (SPS2): biological activities of mutant forms in Escherichia coli

A novel gene, sps2, detected in mouse embryo at the early stages of development has been identified as an analog of the E. coli selenophosphate synthetase gene. Unlike the E. coli enzyme, the presence of selenocysteine in the mouse enzyme is indicated by a TGA codon in the open reading frame of the cDNA. Using an N-FLAG monoclonal antibody, it was shown that the full length N-FLAG-sps2 gene product was expressed in COS-7 cells. To investigate the biological activity of the sps2 gene product in vivo, the mutated sps2 gene, which contains cysteine in the place of the TGA encoded selenocysteine in the wild type, was expressed in the E. coli selD deficient mutant, MB08. Like the E. coli wild type selD gene, the mutant sps2 gene complemented the selD mutation. However, replacement of Cys with either Ala, Ser, or Thr resulted in a loss of ability to complement the selD mutation. The SPS2-CYS protein expressed in E. coli was purified and its catalytic activity was determined. The Km value for ATP was 0.75 mM and Vmax was 9.23 nmole/min/mg protein. These results confirm that the mouse embryonic sps2 gene encodes an eukaryotic selenophosphate synthetase, and that availability of selenophosphate as a selenium donor compound is widespread.

Two distinct mechanisms are involved in 6-hydroxydopamine- and MPP+-induced dopaminergic neuronal cell death: role of caspases, ROS, and JNK

In this study, we examined the possibility that MPTP and 6-hydroxydopamine (6-OHDA) act on distinct cell death pathways in a murine dopaminergic neuronal cell line, MN9D. First, we found that cells treated with 6-OHDA accompanied ultrastructural changes typical of apoptosis, whereas MPP+ treatment induced necrotic manifestations. Proteolytic cleavage of poly-(ADP-ribose)polymerase by caspase was induced by 6-OHDA, whereas it remained uncleaved up to 32 h after MPP+ treatment and subsequently disappeared. Accordingly, 6-OHDA- but not MPP(+)-induced cell death was significantly attenuated in the presence of a broad-spectrum caspase inhibitor, N-benzyloxy-carbonyl-Val-Ala-Asp-fluomethylketone (Z-VAD-fmk). As measured by fluorometric probes, the level of reactive oxygen species (ROS) significantly increased after 6-OHDA treatment. In contrast, the level of dihydroethidium-sensitive ROS following MPP+ treatment remained unchanged while a slight increase in dichlorofluorescin-sentive ROS was temporarily observed. As demonstrated by immunoblot analysis, the level of superoxide dismutase was down-regulated following 6-OHDA treatment, whereas it remained unchanged after MPP+ treatment. Cotreatment of cells with antioxidants such as N-acetylcysteine or Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (MnTBAP, cell-permeable superoxide dismutase mimetic) rescued 6-OHDA- but not MPP(+)-induced cell death, whereas inclusion of catalase or N(G)-nitro-L-arginine had no effect in both cases. In addition, 6-OHDA induced ROS-mediated c-Jun N-terminal kinase (JNK) activation that was attenuated in the presence of N-acetylcysteine or MnTBAP but not catalase or Z-VAD-fmk. In contrast, MPP+ has little effect on JNK activity, indicating that ROS and/or ROS-induced cell death signaling pathway seems to play an essential role in 6-OHDA-mediated apoptosis but not in MPP(+)-induced necrosis in a mesencephalon-derived, dopaminergic neuronal cell line.

Anti-allergic actions of the leaves of Castanea crenata and isolation of an active component responsible for the inhibition of mast cell degranulation

The anti-allergic actions of the leaves of Castanea crenata (Fagaceae) were studied. The water extract demonstrated potent anti-allergic actions in in vivo and in vitro experiments. The oral or intraperitoneal administration of the extract (100 or 200 mg/kg) caused a significant inhibition of the 48 hr-PCA (up to 90%) and the vascular permeability induced by histamine or serotonin in rats (about 80%). The anaphylactic release of beta-hexosaminidase from RBL-2H3 cells was also significantly inhibited by the extract in a dose-dependent manner with an IC50 value of 230 microg/ml. The activity-guided fractionation of the extract, based on the determination of inhibitory effect upon the release of beta-hexosaminidase, led to the isolation of quercetin as an active principle responsible for the inhibition of degranulation.

P-glycoprotein (Pgp) does not affect the cytotoxicity of flavonoids from Sophora flavescens, which also have no effects on Pgp action

Sophoraflavanone, kurarinone (GS08), norkurarinol (GS11), kurarinol (GS12) and kushenol K are cytotoxic flavonoids isolated from Sophora flavescens. In this study, we tested the cytotoxicity of those flavonoids to human cancer cells including P-glycoprotein (Pgp)-expressing HCT15 cells and its multidrug resistant subline, HCT15/CL02 cells. HCT15/CL02 cells revealed resistance to GS08, GS11 and GS12 about 2 fold in comparison with HCT15 cells. Nonetheless, verapamil, a Pgp inhibitor, could not increase the cytotoxicity of all the flavonoids tested. We also investigated that the flavonoids could modulate the Pgp action. At nontoxic concentrations, the flavonoids could not effect on the cytotoxicity of paclitaxel, a well-known Pgp-substrate. The flavonoids also had no effects on the accumulation of rhodamine 123 in all the cells tested at 10 microM. From the results, we concluded that Pgp had no effect on the cytotoxicity of the flavonoids, and the flavonoids also had no effect on the action of Pgp. Our results also suggested that HCT15/CL02 cells had additional mechanisms for drug resistance distinct from Pgp overexpression.

Bovine herpes virus expressing envelope protein (E2) of bovine viral diarrhea virus as a vaccine candidate

The gene encoding the envelope protein (E2) of bovine viral diarrhea virus (BVDV) was expressed under the thymidine kinase (TK) promoter of Korean bovine herpesvirus 1 (BHV-1) isolate. Thymidine kinase negative (TK-) BHV-1 recombinants expressing E2 of BVDV were constructed and the expression of E2 was identified by immunofluorescence and Western blotting. Compared to wild type BHV-1, the recombinant BHV-1 had a delayed cytopathogenic effect in cells. The immunogenicity of the recombinant BHV-1 was examined in guinea pigs and cattle. Although an increase in body temperature was detected for a few days, the inoculated cattle returned to normal temperature with the development of neutralizing antibodies to BVDV.

Cytotoxicity of two novel cisplatin analogues, (CPA)2Pt[DOLYM] and (DACH)Pt[DOLYM], to human cancer cells in vitro

Despite the impressive antitumor activity of cisplatin, two major limitations of the drug, that is severe side effects and drug-resistance of cancer cells, make its use difficult for cancer therapy. These limitations have resulted in a great deal of effort having been expended into structural modifications of cisplatin. In this study, we tested two novel cisplatin analogues, (CPA)2Pt [DOLYM] (COMP-I) and (DACH)Pt[DOLYM] (COMP-II), for the mode of cytotoxic action against human tumor cells comparing with cisplatin and carboplatin in vitro. These two novel analogues had considerable cytotoxic activities against five kinds of human solid tumor cells, and especially COMP-II was more effective on HCT15 colon cancer cells than other compounds. In addition, COMP-II had cytostatic activity at low concentrations (10-0.3 microgram/ml), but other compounds revealed little effect on tumor growth at the low concentration.

Molecular cloning of multiple splicing variants of JIP-1 preferentially expressed in brain

Stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) is activated by a variety of cellular or environmental stresses. Proper regulation of the SAPK/JNK pathway may be critical for cell survival or death under various conditions. In this study, we report the molecular cloning of novel isoforms of JIP-1, which harbor a putative phosphotyrosine interaction domain and a helix-loop-helix domain, as well as an SH3 homologous region in the C terminus. Northern analysis indicates that transcription variant jip-1 is expressed in brain and kidney and transcription variants jip-2 and jip-3 are specifically expressed in brain. In situ hybridization data showed that the hybridized jip messages were heavily concentrated in adult brain, and were particularly enriched in the cerebral cortex and hippocampus, the brain regions vulnerable to pathological states such as hypoxia-ischemia, epilepsy, and Alzheimer's disease. All the deduced protein products of the jip transcription variants appear to have a similar property in that they inhibit the SAPK/JNK stimulation when overexpressed. Inhibition of SAPK activation by overexpression of the novel isoform JIP-2a resulted in suppression of etoposide-induced cell death in a neuroglioma cell line, N18TG. These findings suggest that JIP may play an important role in regulation of the SAPK pathway that is involved in stress-induced cellular responses.

Intravenous calcitriol regresses myocardial hypertrophy in hemodialysis patients with secondary hyperparathyroidism

To evaluate the response of circulating intact parathyroid hormone (iPTH) on myocardial hypertrophy in hemodialysis (HD) patients with secondary hyperparathyroidism (SHPT), echocardiographic and neurohormonal assessments were performed over a 15-week period in 15 HD patients with SHPT before and after calcitriol treatment and 10 HD control patients with SHPT not receiving calcitriol therapy. We prospectively studied a group of 15 patients with significantly elevated iPTH levels (iPTH >450 pg/mL) receiving calcitriol (2 microg after dialysis twice weekly). Clinical assessment, medication status, and biochemical and hematological measurements were performed once a month. Throughout the study, calcium carbonate levels were modified to maintain serum phosphate levels at less than 6 mg/dL, but body weight, antihypertensive medication, and ultrafiltration dose remained constant. In patients treated with calcitriol, an adequate reduction of iPTH levels was found (1,112 +/- 694 v 741 +/- 644 pg/mL; P < 0.05) without changes in values of serum ionized calcium (iCa++), phosphate, or hematocrit. Blood pressure (BP), cardiac output (CO), and total peripheral resistance (TPR) did not significantly change. After 15 weeks of treatment with calcitriol, M-mode echocardiograms showed pronounced reductions in interventricular wall thickness (13.9 +/- 3.6 v 12.8 +/- 3.10 mm; P = 0.01), left ventricular posterior wall thickness (12.5 +/- 2.4 v 11.3 +/- 1.8 mm; P < 0.05), and left ventricle mass index (LVMi; 178 +/- 73 v 155 +/- 61 g/m2; P < 0.01). However, in control patients, these changes were not found after the treatment period. In addition, sequential measurements of neurohormonal mediator levels in patients receiving calcitriol showed that plasma renin (18.5 +/- 12.7 v 12.3 +/- 11.0 pg/mL; P = 0.007), angiotensin II (AT II; 79.7 +/- 48.6 v 47.2 +/- 45.7 pg/mL; P = 0.001), and atrial natriuretic peptide (ANP; 16.6 +/- 9.7 v 12.2 +/- 4.4 pg/mL; P = 0.03) levels significantly decreased, whereas antidiuretic hormone (ADH), epinephrine, and norepinephrine levels did not change significantly. The percent change in LVMi associated with calcitriol therapy had a strong correlation with the percent change in iPTH (r = 0.52; P < 0.05) and AT II (r = 0.47; P < 0.05) levels. We conclude that the partial correction of SHPT with intravenous calcitriol causes a regression in myocardial hypertrophy without biochemical or hemodynamic changes, such as heart rate, BP, and TPR. The changes in plasma levels of iPTH and, secondarily, plasma levels of neurohormones (especially AT II) after calcitriol therapy may have a key role in attenuating ventricular hypertrophy in SHPT.

Ca2+-mediated activation of c-Jun N-terminal kinase and nuclear factor kappa B by NMDA in cortical cell cultures

We examined the possibility that c-Jun N-terminal kinase (JNK) and nuclear factor kappaB (NF-kappaB) might be involved in intracellular signaling cascades that mediate NMDA-initiated neuronal events. Exposure of cortical neurons to 100 microM NMDA induced activation of JNK within 1 min. Activity of JNK was further increased over the next 5 min and then declined by 30 min. Similarly, ionomycin, a selective Ca2+ ionophore, induced activation of JNK. The NMDA-induced activation of JNK was abrogated in the absence of extracellular Ca2+, suggesting that Ca2+ entry is necessary and sufficient for the JNK activation. Immunohistochemistry with anti-NF-kappaB antibody demonstrated nuclear translocation of NF-kappaB within 5 min following NMDA treatment. NMDA treatment also enhanced the DNA binding activity of nuclear NF-kappaB in a Ca2+-dependent manner. Treatment with 3 mM aspirin blocked the NMDA-induced activation of JNK and NF-kappaB. Neuronal death following a brief exposure to 100 microM NMDA was Ca2+ dependent and attenuated by addition of aspirin or sodium salicylate. The present study suggests that Ca2+ influx is required for NMDA-induced activation of JNK and NF-kappaB as well as NMDA neurotoxicity. This study also implies that aspirin may exert its neuroprotective action against NMDA through blocking the NMDA-induced activation of NF-kappaB and JNK.

Desacetylmatricarin, an anti-allergic component from Taraxacum platycarpum

The bioassay-guided fractionation of Taraxacum platycarpum (Compositae) extract led to the isolation of a desacetylmatricarin (1) as an active principle responsible for the anti-allergic property. It showed a potent inhibitory activity upon the beta-hexosaminidase release from RBL-2H3 cells in a dose-dependent manner and the IC50 was 7.5 microM. Two structurally related guaianolide sesquiterpenes, achillin and leucodin, were also examined and their IC50 values were determined as 100 microM and 80 microM, respectively.

The bisbenzylisoquinoline alkaloids, tetrandine and fangchinoline, enhance the cytotoxicity of multidrug resistance-related drugs via modulation of P-glycoprotein

The occurrence of resistance to chemotherapeutic drugs is a major problem for successful cancer treatment and reducing drug accumulation by P-glycoprotein (P-gp) is one of the major mechanisms of multidrug resistance (MDR). The present study was performed to evaluate the MDR-reversal abilities of two bisbenzylisoquinoline alkaloids, tetrandine (TET) and fangchinoline (FAN), compared with verapamil (VER), a well-known P-gp modulator. TET (3.0 microM), FAN (3.0 microM) and VER (10.0 microM) reduced the paclitaxel (TAX) concentration required to achieve 50% inhibition of cell growth (EC50) to HCT15 (P-gp-positive) cells about 3100-, 1900- and 410-fold, and these compounds also reduced the EC50 value of actinomycin D (AMD) about 36.0-, 45.9- and 18.2-fold in the cells, respectively. Meanwhile, TET, FAN and VER had no effect on the cytotoxicity of the drugs to SK-OV-3 (P-gp-negative) cells. On the other hand, TET (3.0 microM), FAN (3.0 microM) and VER (10.0 microM) similarly enhanced the accumulation rates of rhodamine 123, a well known P-gp substrate, in HCT15 cells (200-250%). After efflux for 2 h with fresh medium, TET and FAN also enhanced the residual rate of rhodamine 123 about 5.0- and 2.6-fold in comparison with control, respectively. TET, FAN and VER could not affect the accumulation and residual rate of rhodamine 123 in SK-OV-3 cells. From the result, we conclude that TET and FAN enhanced the cytotoxicity of MDR-related drugs via modulation of P-gp.

Oxyresveratrol as the potent inhibitor on dopa oxidase activity of mushroom tyrosinase

Oxyresveratrol (2,3',4,5'-tetrahydroxystilbene), a naturally occurring compound particularly found in Morus alba L., exhibited a potent inhibitory effect on dopa oxidase activity of tyrosinase which catalyzes rate-limiting steps of melanin biosynthesis. Oxyresveratrol with 0.3 to 5 microM exhibited potent and dose-dependent inhibitions (25 to 84%) on the enzyme activity, where 50% of inhibition was shown at the concentration of about 1 microM. Oxyresveratrol seemed to inhibit the dopa oxidase activity of tyrosinase via a noncompetitive manner (Ki = 9.1 x 10(-7) M) when L-dopa was used as a substrate. Oxyresveratrol exhibited about a 150-fold more potent inhibitory effect than resveratrol (3,4',5-trihydroxystilbene). The more hydroxy groups of the hydroxystilbenes are methylated to be methoxy groups, while the less inhibitory effects on the enzyme activity were exhibited. The results indicate that both the number and positions of hydroxy groups in oxyresveratrol seem to play a critical role in exerting the inhibitory effect on dopa oxidase activity of mushroom tyrosinase.

Reversal of multidrug resistance by novel verapamil analogs in cancer cells

The present study was performed to evaluate the ability of KR-30032 and KR-30035 to overcome multidrug resistance (MDR) by measuring the cytotoxicity and the accumulation rate of rhodamine. Additionally, the adverse cardiac toxicity of KR-30032 and KR-30035 was evaluated by measuring the changes of tension in isolated rat aorta and left ventricular pressure (LVP) in guinea pig heart. KR-30035 potentiated the paclitaxel-induced cytotoxicity to HCT15 [P-glycoprotein (P-gp)-expressed cells] to over 15-fold greater than that of verapamil and KR-30032 was equipotent with verapamil (EC50: 0.07, 5.0 and 3.3 nM at 1.0 microg/ml). KR-30032 and KR-30035 were without effect on cytotoxicity to SK-OV-3 cells (P-gp-non-expressing cells), as well as to tamoxifen-induced cytotoxicity in the above cell types. Maximal rhodamine accumulation rates with KR-30032, KR-30035 and verapamil were 290, 291 and 271% in HCT15 cells; and 451, 970 and 440% in HCT15/CL02 cells, respectively. KR-30032 and KR-30035 were 20- to 25-fold less potent than verapamil in relaxing aorta (EC50: 8.13, 6.40 and 0.32 microM, respectively) and were 12- to 35-fold less potent than verapamil in decreasing LVP in isolated hearts (EC50: 41.8, 14.1 and 1.2 microM, respectively). The results of this study suggest that KR-30032 and KR-30035 are active modulators of MDR with potentially minimal cardiovascular toxicity.

Oral supplementation of L-arginine prevents chronic cyclosporine nephrotoxicity in rats

This study was performed to evaluate the effect of L-arginine (L-Arg) on the prevention of chronic cyclosporine (CsA) nephrotoxicity in rats. Rats pair-fed a low-salt diet (0.05%) were given CsA (15 mg/kg/day s.c.), CsA and L-Arg (L-Arg group, 1.25 g/l water), CsA and N-nitro-L-arginine methyl ester (L-NAME group, 70 mg/l water) or vehicle. After 28 days, the L-Arg group had a higher glomerular filtration rate compared to the CsA (0.42 +/- 0.05 vs. 0.31 +/- 0.06 ml/min/100 g, p < 0.05) and the L-NAME groups (vs. 0.19 +/- 0.04 ml/min/100 g, p < 0.05) and a significantly lower serum creatinine level compared to the CsA (0.70 +/- 0.06 vs. 0.92 +/- 0.12 mg/dl, p < 0.05) and the L-NAME groups (vs. 1.21 +/- 0.17 mg/dl, p < 0.05). The L-Arg group had less fibrosis, tubular injury (TI), and arteriolopathy than the CsA (fibrosis 0.39 +/- 0.14 vs. 0.74 +/- 0.15; TI 1.3 +/- 0.3 vs. 2.0 +/- 0.1; arteriolopathy 33 +/- 7 vs. 48 +/- 17, p < 0.05, respectively) and the L-NAME groups (fibrosis vs. 1.67 +/- 0.32, TI vs. 2.6 +/- 0.3, arteriolopathy vs. 63 +/- 10, p < 0.05, respectively). Plasma renin activity in the L-Arg group was less than in the CsA (18 +/- 2 vs. 23 +/- 3 ng Ang I/ml/h, p < 0.05) and the L-NAME groups (vs. 30 +/- 3 ng Ang I/ml/h, p < 0.05). Nitric oxide production in L-Arg group was higher than in the CsA (24.2 +/- 1.7 vs. 11.1 +/- 1.5 mumol/24 h, p < 0.05) and the L-NAME groups (vs. 8.4 +/- 1.0 mumol/24 h, p < 0.05). In conclusion, the nitric oxide pathway is associated with the pathogenesis of chronic CsA nephrotoxicity, and exogenous L-Arg supplementation is effective in reducing chronic CsA nephrotoxicity in rats.

Nitric oxide modulates the c-Jun N-terminal kinase/stress-activated protein kinase activity through activating c-Jun N-terminal kinase kinase

Nitric oxide is a signaling molecule that has a broad range of physiological functions, including neurotransmission, macrophage activation, and vasodilation. The mechanism by which nitric oxide regulates signal transduction mediating diverse biological activities is not fully understood, however. Here, we demonstrate that nitric oxide induced the stimulation of c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase (SAPK) in intact cells. Exposure of cultured HEK293 cells to sodium nitroprusside, a nitric oxide releasing agent, resulted in the stimulation of JNK1 activity. The sodium nitroprusside-induced stimulation of JNK1 activity was abolished by treatment of cells with N-acetylcysteine. Nitric oxide production from HEK293 cells ectopically expressing nitric oxide synthases resulted in the stimulation of JNK1 activity, while JNK1 stimulation in nitric oxide synthase-overexpressing cells was abrogated by a nitric oxide synthase inhibitor, NG-nitro-L-arginine. Furthermore, exposure of cells to sodium nitroprusside resulted in the stimulation of JNK kinase (JNKK1/SEK1). Taken together, our data suggest that nitric oxide modulates the JNK activity through activating JNKK1/SEK1.

Novel multidrug-resistance modulators, KR-30026 and KR-30031, in cancer cells

The present study was performed to evaluate the ability of KR-30026 and KR-30031 to overcome multidrug resistance (MDR) by measuring the cytotoxicity of paclitaxel and the rate of rhodamine accumulation, which were then compared with verapamil. KR-30026 potentiated the paclitaxel-induced cytotoxicity of HCT15 to over 60 fold greater than that of verapamil, and KR-30031 was equipotent with verapamil (EC50: 0.00066, 0.04 and 0.05 nM at 4.0 micrograms/ml, respectively). KR-30026 and KR-30031 were without effect on paclitaxel-induced cytotoxicity to SK-OV-3 cells, as well as on tamoxifen-induced cytotoxicity to HCT15, HCT15/CL02 and SK-OV-3 cells. Maximal rhodamine accumulation by KR-30026, KR-30031 and verapamil were similar in HCT15 cells, while KR-30026 was more potent than verapamil in HCT15/CL02 cells (721 and 440%, respectively). To evaluate the cardiac toxicity of KR-30026 and KR-30031, the changes of tension in isolated rat aorta and left ventricular pressure (LVP) in guinea pig heart were determined; KR-30026 and KR-30031 were 15-40 and 25-70 fold less potent than verapamil, respectively. These results suggest that KR-30026 and KR-30031 are active modulators of MDR with potentially minimal cardiovascular toxicity.

Activation of c-Jun N-terminal kinase antagonizes an anti-apoptotic action of Bcl-2

Bcl-2 is an intracellular membrane-associated protein that prevents cell death induced by a variety of apoptotic stimuli. A mechanism by which Bcl-2 exerts an anti-cell death effect is, however, not fully understood. In the present study, Bcl-2 suppressed cell death of N18TG neuroglioma cells caused by various apoptotic stresses, including etoposide, staurosporine, anisomycin, and ultraviolet irradiation. Concomitantly, Bcl-2 disrupted a signaling cascade to the c-Jun N-terminal kinase activation induced by the apoptotic stresses. Bcl-2 also prevented the etoposide-induced stimulation of MEKK1. Furthermore, overexpression of c-Jun N-terminal kinase antagonized the death-protective function of Bcl-2. These data suggest that suppression of the c-Jun N-terminal kinase signaling pathway may be critical for Bcl-2 action.

[Cloning and sequencing of p33 in a Korean isolate of Theileria sergenti]

The gene encoding the 33 kDa piroplasm surface protein of Theileria sergenti isolated in Korea was cloned and the nucleotide sequence was determined by dideoxy chain termination method. The cloned gene corresponds to 869 bp encoding an open reading frame 283 amino acids. Comparison of the sequence between Korean and Japanese isolates showed 99.4% homology rate in the nucleotide sequence and 98.9% homology rate in the amino acid sequence.

[Rapid detection of Theileria sergenti by polymerase chain reaction]

Four separate pairs of oligonucleotide primers within the coding region in a T. sergenti 33-kDa surface protein gene were selected to detect T. sergenti by PCR. The specificity of PCR-amplified DNA was examined by digestion with restriction enzyme and Southern blot hybridization using T. sergenti p33 DNA probe. PCR appears to be specific for T. sergenti, without detectable signals from uninfected erythrocytes, uninfected bovine leukocytes and other hemoparasites, including A. marginale and B. ovata. Although 46 of 71 specimens (64.8%) from grazing cattle were microscopically positive, PCR in this study showed that 64 specimens (88.7%) were positive. Therefore, PCR proves a useful diagnostic tool for detecting T. sergenti-infected cattle. In addition, it is also revealed that PCR was significantly more sensitive than traditional microscopic examination using Giemsa's stain.

Memory deficits in schizophrenia: inadequate assimilation or true amnesia? Findings from the Wechsler Memory Scale--revised

Researchers disagree about why patients with schizophrenia perform poorly on memory tests. Some argue the presence of a fundamental memory deficit stemming from dysfunction in medial temporal lobe structures, principally the hippocampus. Others, stressing the contributions of impaired attention or executive failings such as a disorganized approach to learning, implicate larger neural networks. We compared data from psychometrically similar procedures, the Wechsler Memory Scale-Revised (WMS-R) and Wechsler Adult Intelligence Scale-Revised (WAIS-R), generated by 17 schizophrenia-spectrum patients and 33 psychiatric controls. We then compared our findings in detail with all published WMS-R/WAIS-R schizophrenia data. Our findings and the literature indicate that the acquisition of new information is disrupted in schizophrenia, but they provide little support for claims that memory deficits are especially pronounced relative to other weaknesses. Since schizophrenia patients exhibit reasonable retention following intervening activity, theories that place primary emphasis upon hippocampal dysfunction are not well supported.

Evaluation of acute renal failure in bacterial allograft pyelonephritis using abdominal CT and graft biopsy

The causes of acute renal failure in bacterial allograft pyelonephritis were evaluated using abdominal CT and graft biopsy. Twenty-one recipients, who showed a poor response to antibiotic therapy, comprised this study group. The diagnostic approach taken with this poor responder group was first to perform abdominal CT. If a focal lesion was identified on abdominal CT, a diagnosis of acute focal bacterial nephritis or renal abscess was made. If no focal lesion was found, a graft biopsy was performed for diagnosis. Abdominal CT revealed focal lesions in 9 of the 21 recipients, and renal biopsy showed superimposed acute rejection in 8 of the 12 recipients biopsied. In conclusion, acute renal failure in allograft pyelonephritis is associated with not only severe infection but also a superimposed acute rejection process. Therefore, imaging study and graft biopsy are recommended in the poor responder group.

Serum and urine soluble HLA class I antigen concentrations are increased in patients with hemorrhagic fever with renal syndrome

OBJECTIVES

In order to evaluate the association between the Hantaan virus-induced cellular-immune response and clinical severity in patients with hemorrhagic fever with renal syndrome (HFRS).

METHODS

We serially measured the serum (n = 16) and urine (n = 6) concentrations of soluble HLA class 1 antigen (sHLA-l) and clinical powameters in patients with HFRS.

RESULTS

Serum sHLA-I concentrations in patients with HFRS were significantly higher than those in controls throughout all clinical phases (p < 0.01). The highly elevated Serum sHLA-I concentrations peaked in the oliguric phase and declined gradually through the phases of HFRS. Serum sHLA-l concentrations in patients with hypotensive episode were higher than in those without the episode (5,85 +/-2,184 vs. 2,389 +/- 860 ng/ml in oliguric phase, 4.11 +/- 1,952 vs. 1,502 +/- 592 ng/ml in diuretic phase, p < 0.05), and serum sHLA-l levels showed a significant correlation with blood WBC count (r = 0.75 in the febrile and hypotensive phase, p < 0.01) and serum creatinine concentrations (r = 0.64 in the oliguric phase, p < 0.01), respectively, Urine sHLA-I levels in the oliguric phase were significantly higher than those in the diuretic phase (390 +/- 155 vs. 214 +/- 45 ng/mg Cr, p < 0.05) and urine sHLA-I levels are associated with severe illness in patients with HFRS. The higher serum sHLA-I are associated with severe illness in patients with HFRS. The persistent elevation of serum sHLA-I during all phases of HFRS might be related to increased production due to prolonged cellular immunologic stimulation by the Hantaan virus rather than decreased excretion of sHLA-I through the kidney.

CONCLUSION

We suggest that the serum and urine sHLA-I concentrations can be used as a stable and objective parameter for monitoring clinical severity and renal dysfunction in patients with HFRS.