Motherless case in paternity testing

In paternity test using the DNA evidence, the analysis of the deficient case that the DNA profiles of mother or alleged father are not available is different from that of the trio case analyzed routinely. However, the motherless case that the genotypes of mother is not available has been requested and analyzed like the trio case. In this paper, we compared the motherless case and the trio case through the mean exclusion chance describing the probability of exclusion for a genetic marker system and the distribution of the probability of paternity calculated using the three current methods. We have also shown a case which can be falsely discriminated if it were requested in the analysis of the motherless case, and conclude that the analysis of the motherless case should be carefully conducted and the level for the discrimination should be different from that of the trio case.

High-level expression of antimicrobial peptide mediated by a fusion partner reinforcing formation of inclusion bodies

A gene expression system for antimicrobial peptides, which could be effectively used for various studies or applications of the antimicrobial peptides, has been developed. To avoid the harmful effects on an expression host, Escherichia coli, the antimicrobial peptides were expressed as fusion proteins with a polypeptide F4, which is a truncated PurF fragment that highly tends to form inclusion bodies. Seven different kinds of antimicrobial peptides have been successfully expressed by this expression system and the resulting expression level of fusion proteins reached up to 30% of total cell proteins. To confirm the identity of the recombinant peptide, MSI-344 was selected as a model peptide and purified to homogeneity, and we could obtain the recombinant MSI-344 of a high purity and with a good yield, which was identical to the authentic peptide in the aspects of the chemical and antimicrobial properties. These results show that the neutral fusion partner, which reinforces the formation of inclusion bodies, could mediate a high-level expression of the antimicrobial peptides.

Cross talk in holographic memories with lensless phase-conjugate holograms

Recently holographic memory with lensless phase-conjugate holograms has attracted much attention because it opens up the possibility of compact holographic memories. We investigate cross-talk noise in compact holographic memories with angular multiplexing. It turns out that the optimum angular separation is the same as that for the Fourier plane hologram in the leading order and that the noise-to-signal ratio is independent of the positions in the output plane, similar to the case of the image plane hologram.

A convenient method for oxidation of organophosphorus pesticides in organic solvents

Since organophosphorus pesticides can be oxidized to oxons in vivo and in the environment and their determination based on inhibition of cholinesterases can be more sensitive after their oxidation to oxons, development of an efficient method for their in vitro oxidation is important for their toxicological and analytical studies. This study demonstrated that treatment of organophosphorus pesticides with 10 molar excess bromine in acetonitrile is a rapid and efficient method for their oxidation. For the nine organophosphorus pesticides tested, the reaction was complete within a few seconds. All reactions gave the respective oxons as single major product, except that of fenthion, which gave two major products, the respective oxon and another product from further oxidation of the oxon. The yields of the oxons were 82-100%. The inhibitory power of the pesticides on acetylcholinesterase before and after oxidation was measured and, for all pesticides tested, the power after oxidation was much higher than that before oxidation. Inhibition calibration curves for both unoxidized and oxidized forms of fenitrothion and parathion were obtained. The sensitivity of the detection of these pesticides was much higher after oxidation.

Coexistence of disseminated superficial porokeratosis in childhood with congenital linear porokeratosis

Porokeratosis is a genodermatosis characterized by abnormal epidermal keratinization with the histologic finding of cornoid lamella. To date, five clinical variants have been identified. However, the coexistence of these variants in a single patient has been described only rarely. We report a 5-year-old girl with the simultaneous occurrence of porokeratotic lesions in linear and disseminated patterns. Linear lesions were detected at birth and the disseminated lesions developed at the age of 3 years. Histologically the lesions had cornoid lamella, which is typical of this condition.

Potentiation of tumor necrosis factor-alpha-induced apoptosis by mistletoe lectin

Mistletoe lectins (MLs) constitute the active principle in extract preparations from mistletoe, commonly used as immunomodulator in adjuvant tumor therapy. MLs, classified as type II ribosome inactivating proteins, inhibit protein synthesis. Inhibitors of protein synthesis may modify cancer cell response to tumor necrosis factor-alpha (TNF). In the present study, we have hypothesized that the anticancer efficacy of TNF may be potentiated by MLs. In deed, simultaneous treatment of human cervix carcinoma HeLa or breast carcinoma MCF-7 cells with MLs isolated from European or Korean mistletoe rendered them more sensitive to induction of apoptosis by TNF. The mechanism by which MLs amplify the effect of TNF may involve suppression of the survival protein synthesis.

The real cost of aspirin

Aspirin is a widely used drug and perceived by most physicians to be inexpensive. High rates of concurrent gastroprotective agents are reported from a study of cardiology outpatients. Aspirin takers are more likely to also be taking a proton pump inhibitor, H(2) antagonist, or antacid than non-aspirin takers. They are more than 10 times as likely to be experiencing upper gastrointestinal symptoms. Although aspirin is inexpensive, it is emphasised that the overall cost implications for therapy can be significant and it is suggested that it may be more appropriate to consider the use of alternative antiplatelet agents in patients who tolerate aspirin poorly.

Improved outcomes in patients with acute allergic syndromes who are treated with combined H1 and H2 antagonists

STUDY OBJECTIVE

Although the addition of H(2) blockers to H(1) antagonists has been promoted for use in anaphylaxis, there have been no large studies establishing the advantage of this approach in treating acute allergic syndromes. In this study we tested the hypothesis that combined H(1) and H(2) blockage results in improved outcomes in patients treated for acute allergic syndromes compared with treatment with H(1) blockade alone.

METHODS

In a randomized, double-blind, placebo-controlled trial, 91 adult patients with acute allergic syndromes were treated with either 50 mg of diphenhydramine and saline solution (control group) or with 50 mg of diphenhydramine and 50 mg of ranitidine (active group). These patients were treated with parenteral administration. Patients were recruited from an emergency department at an urban academic medical center. The primary endpoints were resolution of urticaria, angioedema, or erythema at 2 hours after protocol treatment. Areas of cutaneous involvement, heart rates, blood pressures, respiratory findings, and symptom scores were also assessed at baseline, 1 hour, and 2 hours.

RESULTS

There were significantly more patients without urticaria at 2 hours among the patients in the active group compared with those in the control group. Both groups had similar proportions of urticaria at baseline. Logistic regression models to predict resolution of urticaria, which accounted for baseline urticarial involvement, showed odds ratios in favor of the active group treatment. Similar findings were observed when the absence of both urticaria and angioedema was considered as the dependent variable. There was not a significant difference between the 2 groups with regard to the absence of erythema or angioedema (irrespective of the presence of urticaria) at 2 hours. Blood pressure and symptoms did not show differences between the 2 groups over time. Lower heart rates were observed 1 hour after treatment in the active treatment group (mean reduction 10 beats/min) compared with those found in the placebo group (mean reduction 6 beats/min).

CONCLUSION

These data show that adding H(2) blockers to H(1) antagonists results in additional improvement of certain cutaneous outcomes for patients presenting with acute allergic syndromes. These findings favor the recommendation for using combined H(1) and H(2) antihistamines in acute allergic syndromes.

Coronary flow reserve is reflective of myocardial perfusion status in acute anterior myocardial infarction

Our objective was to determine whether coronary vasodilatory reserve (CVR) correlates with the perfusion state of infarct zone in early recovery phase of acute anterior myocardial infarction (AMI). We studied 14 patients (11 males; mean age, 46 years) who had AMI and 6 control subjects who had chest pain but normal coronary angiograms. All patients underwent successful percutaneous revascularization of left anterior descending (LAD) coronary artery. Coronary flow velocity was measured using intracoronary (IC) Doppler at baseline and following IC injection of 18 microg of adenosine. Myocardial perfusion was evaluated by myocardial contrast echocardiography (MCE). CVR was higher in patients without a perfusion defect on MCE than in those with (2.48 +/- 0.21 vs. 1.66 +/- 0.13, P = 0.001). Subjects with a perfusion defect had a lower CVR than controls (1.66 +/- 0.13 vs.2.40 +/- 0.18, P < 0.05). CVR was > 2.0 in all subjects without a perfusion defect. There was a strong correlation between the magnitude of myocardial opacification in the LAD territory and CVR (r = 0.80, P < 0.01). Increase in peak diastolic flow velocity after adenosine infusion, but not systolic flow velocity, correlated with myocardial opacification index (r = 0.63, P = 0.016). CVR of infarct-related artery correlated closely with the perfusion status of the myocardium in infarct zone and those with a CVR > 2.0 had normal myocardial perfusion. These data suggest that CVR may be used to determine the perfusion state of the myocardium in the infarct zone, which is a known predictor of myocardial viability. Cathet. Cardiovasc. Intervent. 51:281-286, 2000.

Two closely related cDNAs encoding actin-depolymerizing factors of petunia are mainly expressed in vegetative tissues

Actin-depolymerizing factor (ADF) is one of the small actin-binding proteins that regulate actin dynamics in cells. We have isolated two cDNA clones, PhADF1 and PhADF2, encoding ADF from cDNA libraries constructed from petal protoplast cultures and flowers of Petunia hybrida. PhADF1 and PhADF2 encode polypeptides of 139 and 143 amino acids with a calculated molecular mass of 16.04 and 16.51kDa, respectively. Co-sedimentation assay showed that the recombinant PhADF1 protein produced in Escherichia coli binds to F-actin at pH7. 0 and preferentially depolymerizes it at pH8.0. Gene tree analysis indicates that the plant ADF family can be grouped into four classes, and PhADFs are included in class I. Southern blot analyses revealed that one or two copies of PhADF genes are present in petunia genome, and several other related isoforms also exist. Northern blot analyses indicated that PhADF1 and PhADF2 are closely related and abundantly expressed in every plant organ except pollen. In addition, they are highly accumulated in mature vegetative tissue (petal, leaf, and stem). Our results indicate that the transcription of petunia ADF genes is differentially regulated by developmental signals.

Enhancement of nuclear factor-kappaB activation and protein tyrosine phosphorylation by a tyrosine phosphatase inhibitor, pervanadate, involves reactive oxygen species in silica-stimulated macrophages

Reactive oxygen species (ROS) and phosphorylation events mediated by tyrosine kinase are involved in silica-induced nuclear factor-kappa B (NF-kappaB) activation. Protein tyrosine phosphatase (PTPase) acts to limit protein tyrosine phosphorylation. In the present study, we investigated the role of PTPase in NF-kappaB activation and tyrosine phosphorylation in silica-stimulated macrophages, and the involvement of ROS in these responses. Treatment of mouse peritoneal macrophages (RAW264.7 cells) with a PTPase inhibitor, pervanadate, markedly enhanced the DNA-binding activity of NF-kappaB in the presence or absence of silica. The stimulatory effect of pervanadate on NF-kappaB activation was also demonstrated in LPS-stimulated macrophages. A specific inhibitor of protein tyrosine kinase (PTK), genistein, prevented the NF-kappaB activation induced by pervanadate in the presence of silica while inhibitors of protein kinase A or C, such as staurosporine or H7, had no inhibitory effect on NF-kappaB activation. A variety of antioxidants, such as catalase, superoxide dismutase, N-acetyl cysteine (NAC), and pyrrolidine dithiocarbamate, inhibited NF-kappaB activation induced by pervanadate in the presence of silica. Furthermore, pervanadate markedly enhanced silica- or LPS-induced protein tyrosine phosphorylation in cells. Treatment of macrophages with NAC abolished the increase in tyrosine phosphorylation in cells stimulated with the combination of pervanadate and either silica or LPS or with silica alone. The results suggest that PTPase may play a crucial role in the negative regulation of silica-signaling pathways leading to NF-kappaB activation in macrophages. Furthermore, ROS appear to be involved in downstream signaling between PTPase inhibition and NF-kappaB activation.

Hepatocyte growth factor stimulates the growth and activates mitogen-activated protein kinase in human hepatoma cells

Hepatocyte growth factor (HGF) is a potent mitogen for hepatocytes and various epithelial cells. Unexpectedly, it has been reported to inhibit the growth of hepatoma cells in vitro. To clarify this phenomenon, we examined the effects of recombinant baculovirus-expressed HGF on the growth of 6 human hepatoma cell lines. The growth of Hep3B and HepG2 cells was markedly stimulated to 1.8- and 1.7-fold, respectively, PLC/PRF/5 to 1.4-fold, and SK-Hep-1 to 1.2-fold in a dose-dependent manner under HGF concentrations below 20 ng/ml. Neither HuH-7 nor HCC36 were affected. None of these cells were inhibited. All these cells expressed c-Met, the membrane receptor for HGF, and their c-Met would be activated to be phosphorylated upon addition of HGF. They also contained the ERK2 subgroup of mitogen-activated protein kinases (MAPKs). When HGF was added, their ERK2 would also be phosphorylated. The extent of ERK2 phosphorylation was partially correlated to their growth response to HGF. In conclusion, HGF could stimulate the growth of certain human hepatoma cells, probably through activation of c-Met and MAPKs.

Pentoxifylline potentiates nitric oxide production in interleukin-1beta-stimulated vascular smooth muscle cells through cyclic AMP-dependent protein kinase A pathway

In the present study, we observed that pentoxifylline (PTX) significantly augmented the nitric oxide (NO) production and the iNOS gene expression by interleukin-1beta (IL-1beta)-stimulated vascular smooth muscle cells (VSMCs). The enhancing effects of PTX on the IL-1beta-induced NO production was associated with an increased intracellular cyclic AMP (cAMP) levels, and the synergistic effects of PTX on the IL-1beta-induced NO production was blocked by cAMP-dependent protein kinase A (PKA) inhibitors. PKA inhibitors, KT5720 and H89, markedly decreased the augmented expression of iNOS gene whereas ODQ, a soluble guanylate cyclase inhibitor, did not affect the enhancing effect. In addition, the pretreatment with KT5720 or H89 abolished the increased translocation of the p65 subunit of NF-kappaB into the nucleus by PTX in the IL-1beta-stimulated VSMCs. These results suggest that enhancing effects of PTX on the iNOS gene expression in the IL-1beta-stimulated VSMCs is mediated predominantly through the activation of NF-kappaB via cAMP-dependent PKA pathway.

Regulation of Gadd45gamma expression by C/EBP

The Gadd45gamma (growth arrest and DNA damage-inducible) gene is activated transcriptionally by at least two kinds of agents: DNA damaging agent such as methyl methanesulfonate (MMS) and UV radiation, or cytokines such as interleukin (IL)-6, IL-2 and granulocyte colony-stimulating factor (G-CSF). To investigate the sequences and transcription factors involved in induction of Gadd45gamma after treatment with IL-6, the human gene was cloned and sequenced. We found C/EBP (CCAAT/enhancer-binding protein) family proteins, major transcription factors in the IL-6 signal transduction pathway, could regulate the transcriptional activity of the Gadd45gamma promoter. In addition, a noncanonical C/EBP-binding site within the Gadd45gamma promoter where C/EBPbeta and C/EBPdelta could bind, was identified by electrophoretic mobility shift assay (EMSA) and reporter gene analysis. Furthermore, we found a coordinated expression profile between Gadd45gamma mRNA and C/EBPs (beta and delta) protein during the differentiation of M1 cells: the amount of Gadd45gamma transcripts became maximal when both C/EBPbeta and C/EBPdelta levels were high, on day 1 of differentiation of M1 cells after treatment with IL-6. These findings suggest that mitotic growth arrest coupled to M1 cell differentiation is mediated by C/EBPs stimulation of growth arrest-associated genes such as Gadd45gamma.

Simultaneous determination of aceclofenac and diclofenac in human plasma by narrowbore HPLC using column-switching

A fully automated narrowbore high performance liquid chromatography (HPLC) with column-switching was developed for the simultaneous determination of aceclofenac and diclofenac from human plasma samples. Plasma sample (100 microl) was directly introduced onto a Capcell Pak MF Ph-1 column (20 x 4 mm I.D.) where primary separation was occurred to remove proteins and concentrate target substances using acetonitrile potassium phosphate (pH 7, 0.1 M) (14:86, v/v). The drug molecules eluted from MF Ph-1 column were focused in an intermediate column (35 x 2 mm I.D.) by the valve switching step. The substances enriched in intermediate column were eluted and separated on the narrowbore phenyl hexyl column (100 x 2 mm I.D.) using acetonitrile-potassium phosphate (pH 7, 0.02M) (33:67, v/v) when the valve status was switched back to A position. The method showed excellent sensitivity (detection limit of 10 ng ml(-1)) with small volume of samples (100 microl), good precision and accuracy, and speed (total analysis time 17 min) without any loss in chromatographic efficiency. The response was linear (r2 > or = 0.999) over the concentration range of 50-10,000 ng ml(-1).

Achondrogenesis type II (Langer-Saldino achondrogenesis): a case report

Achondrogenesis is a lethal form of congenital chondrodystrophy characterized by extreme micromelia. We describe a case of achondrogenesis type II (Langer-Saldino achondrogenesis) detected by prenatal ultrasonography at 20-week gestation. A dwarfed fetus with large head, short neck and chest, prominent abdomen and short limbs was terminated transvaginally. Radiologic and histopathologic examination revealed features of mild form of achondrogenesis type II. Although the case had no known risk factor and the phenotypic abnormality was mild, modern development in prenatal screening made the early detection possible.

Predictors of renal outcome in diffuse proliferative lupus nephropathy: data from repeat renal biopsy

BACKGROUND

Diffuse proliferative lupus nephropathy (DPLN) is the most frequent and severe form of renal disease in patients with systemic lupus erythaematosus. Histological parameters at the initial biopsy of patients with DPLN that would predict the progression of renal pathology or function at the second biopsy are not clearly defined.

METHODS

The prognostic significance of renal histological indices, such as glomerular activity index and volume density of cortical interstitium [Vv(int/cortex)], was evaluated from successive renal biopsies in 21 patients with DPLN.

RESULTS

At the time of the second biopsies, performed an average of 43 months after the first biopsies, seven patients (33%) showed progressive renal insufficiency. Only three cases (14%) transformed to World Health Organization class I or III. The seven patients with clinical progression exhibited a higher frequency of hypertension, higher percent glomerulosclerosis, and larger Vv(int/cortex) at the time of second biopsy as compared with the 14 patients without renal insufficiency. At the first biopsy, patients with clinical progression showed a higher glomerular activity index (2.9+/-1.2 vs 1.3+/-0.8, P<0.05) and larger Vv(int/cortex) (0.13+/-0.07 microm(3)/microm(3) vs 0.05+/-0.03 microm(3)/microm(3), P<0.05) than the patients without progression. The glomerular activity index at the first biopsy correlated directly with per cent glomerulosclerosis, Vv(int/cortex), and serum creatinine level at the second biopsy. Vv(int/cortex) in the first biopsy also showed a significant relation with per cent glomerulosclerosis and serum creatinine level at the second biopsy.

CONCLUSIONS

These results suggest that higher glomerular activity and larger interstitial volume density at the initial biopsy can predict future progression of renal pathology or function in DPLN.

Characterization and cDNA cloning of two glycine- and histidine-rich antimicrobial peptides from the roots of shepherd's purse, Capsella bursa-pastoris

Two novel antimicrobial peptides were isolated and characterized from the roots of shepherd's purse, Capsella bursa-pastoris. These antimicrobial peptides, named shepherin I and shepherin II, consist of 28 and 38 amino acids, respectively, and are glycine- and histidine-rich peptides. Shepherin I and shepherin II have 67.9% and 65.8% (mol/mol) glycine, respectively, and 28.6% and 21.1% (mol/mol) histidine, respectively. Both shepherins have a Gly-Gly-His motif. These antimicrobial peptides exhibit antimicrobial activity against Gram-negative bacteria and fungi. Circular dichroism spectra of shepherin I and shepherin II showed that shepherin I and shepherin II in 50% trifluoroethanol have 66.7% and 75% random coils, respectively, without any alpha-helices. cDNA sequence analysis revealed that shepherin I and shepherin II are produced from a single polypeptide, designated shep-GRP, consisting of 120 amino acids; shep-GRP has five distinct domains, an amino-terminal putative signal peptide, a shepherin I, a linker dipeptide, a shepherin II and a carboxy-terminal peptide. Southern blot analysis indicates that the gene encoding shepherins belongs to a low-complexity gene family. Northern blot analysis revealed that transcripts of shep-GRP are present in roots but not in leaves and stems.

Cloning of the histidine biosynthetic genes from Corynebacterium glutamicum: organization and analysis of the hisG and hisE genes

The physically linked hisG and hisE genes, encoding for ATP-phosphoribosyltransferase and phosphoribosyl-ATP-pyrophosphohydrolase were isolated from the Corynebacterium glutamicum gene library by complementation of Escherichia coli histidine auxotrophs. They are two of the nine genes that participate in the histidine biosynthetic pathway. Molecular genetics and sequencing analysis of the cloned 9-kb insert DNA showed that it carries the hisG and hisE genes. In combining this result with our previous report, we propose that all histidine biosynthetic genes are separated on the genome by three unlinked loci. The coding regions of the hisG and hisE genes are 279 and 87 amino acids in length with a predicted size of about 30 and 10 kDa, respectively. Computer analysis revealed that the amino acid sequences of the hisG and hisE gene products were similar to those of other bacteria.

Purification, characterization, and primary structure of a chitinase from Pseudomonas sp. YHS-A2

A chitinase gene (chiA) from Pseudomonas sp. YHS-A2 was cloned into Escherichia coli using pUC19. The nucleotide sequence determination revealed a single open reading frame of chiA comprised of 1902 nucleotide base pairs and 633 deduced amino acids with a molecular weight of 67,452 Da. Amino acid sequence alignment showed that ChiA contains two putative chitin-binding domains and a single catalytic domain. Two proline-threonine repeat regions, which are linkers between catalytic and substrate-binding domains in some cellulases and xylanases, were also found. From E. coli, ChiA was purified 12.8-fold relative to the periplasmic fraction. The Michaelis constant and maximum initial velocity for p-nitrophenyl-N,N'-diacetylchitobiose were 1.06 mM and 44.4 micromol/h per mg protein, respectively. The purified ChiA binds not only to colloidal chitin but also to other substrates (avicel, chitosan, and xylan), but the binding affinity of avicel, chitosan, and xylan is around 10 times lower than that of colloidal chitin. The reaction of ChiA with colloidal chitin and chitooligosaccharides (trimer-hexamer) produced an end product of N,N'-diacetylchitobiose, indicating that ChiA is a chitobiosidase.

Striatocapsular haemorrhage

Haemorrhages in the striatocapsular area, or striatocapsular haemorrhages (SCHs), have been regarded as a single entity, although the area is composed of several functionally discrete structures that receive blood supply from different arteries. We analysed the morphological and clinical presentations of 215 cases of SCHs according to a new classification method we have designed on the basis of arterial territories. SCHs were divided into six types: (i) anterior type (Heubner's artery); (ii) middle type (medial lenticulostriate artery); (iii) posteromedial type (anterior choroidal artery); (iv) posterolateral type (posteromedial branches of lateral lenticulostriate artery); (v) lateral type (most lateral branches of lateral lenticulostriate artery); and (vi) massive type. The anterior type (11%) formed small caudate haematomas, always ruptured into the lateral ventricle, causing severe headache, and mild contralateral hemiparesis developed occasionally. The outcome was excellent. The middle type (7%) involved the globus pallidus and medial putamen, frequently causing contralateral hemiparesis and transient conjugate eye deviation to the lesion side. About 50% of the patients recovered to normal. The posteromedial type (4%) formed very small haematomas in the posterior limb of the internal capsule and presented with mild dysarthria, contralateral hemiparesis and sensory deficit, with excellent outcome in general. The posterolateral type (33%) affected the posterior half of the putamen and posterior limb of the internal capsule and presented with impaired consciousness and contralateral hemiparesis with either language dysfunction or contralateral neglect. The outcome was fair to poor but there were no deaths. The lateral type (21%) formed large elliptical haematomas between the putamen and insular cortex. Contralateral hemiparesis with language dysfunction or contralateral neglect developed frequently but resolved over several weeks. The clinical outcome was relatively excellent except when the haematoma size was very large. The massive type (24%) formed huge haematomas affecting the entire striatocapsular area. Marked sensorimotor deficits and impaired consciousness, ocular movement dysfunctions including the 'wrong-way' eyes were observed quite frequently. The outcome was very poor with a case fatality rate of 81%. The clinico-radiological presentations suggested its origin was the same as the posterolateral type.

LCC, a cerebroside from Lycium chinense, protects primary cultured rat hepatocytes exposed to galactosamine

Primary cultures of rat hepatocytes exposed to galactosamine (GalN) were used as a screening system to assess whether a new cerebroside, LCC, isolated from the fruits of Lycium chinense, exhibits hepatoprotective activity. Cultured rat hepatocytes injured with GalN routinely release glutamic pyruvic transaminase (GPT) and sorbitol dehydrogenase (SDH) into the culture medium. Treatment of these GalN-injured primary cultures with LCC markedly blocked the release of both GPT and SDH in a dose-dependent manner over concentrations of LCC ranging from 1 microM to 10 microM. To investigate the mechanism of action for the hepatoprotective activity of LCC, the extent of [(3)H]-uridine incorporation into RNA was measured in GalN-injured cultures of rat hepatocytes. [(3)H]-Uridine incorporation was significantly decreased in injured hepatocytes. LCC, however significantly restored the incorporation of [(3)H]-uridine into RNA in a dose-dependent manner over concentrations ranging from 1 microM to 10 microM. LCC also blocked the suppression of RNA synthesis caused by actinomycin D in a dose-dependent manner. These data suggest that LCC may have prominent hepatoprotective activity and that its therapeutic value should be investigated further.

MPP(+) increases the vulnerability to oxidative stress rather than directly mediating oxidative damage in human neuroblastoma cells

MPP(+), an active metabolite of MPTP, causes a dopaminergic neuronal degeneration similar to that observed in Parkinson's disease. Current data suggest that MPP(+)-induced cytotoxicity may be mediated by oxygen free radicals. To evaluate this hypothesis, we first investigated whether MPP(+) could cause oxidative stress by producing oxygen free radicals in the SH-SY5Y, human neuroblastoma cell line. MPP(+) was toxic to the cells dose-dependently but did not increase the level of lipid peroxidation at toxic concentrations. Second, we examined the effects of various antioxidants and an inhibitor of nitric oxide synthase (NOS) on the development of MPP(+) cytotoxicity. Pretreatment with antioxidants such as ascorbic acid, Trolox, phenyl-tertiary-butyl-nitrone (PBN), which show protective effects on tert-butyl hydroperoxide (tBOOH) toxicity did not attenuate MPP(+) cytotoxicity. Similarly, the combination of antioxidant enzymes, SOD and catalase (50 U/ml, respectively), did not protect the cells from the toxic action of MPP(+). Also N-nitro-l-arginine methyl ester (NAME), a competitive inhibitor of NOS, and combined incubation with NAME and antioxidant enzymes failed to attenuate MPP(+) cytotoxicity. On the other hand, a sublethal dose of MPP(+) potentiated iron and H(2)O(2)-induced cytotoxicity. These results suggest that oxygen free radicals may not be a primary cause of MPP(+)-induced cell death but that MPP(+) increases the vulnerability of cells to oxidative stress.

Human pyridoxal kinase: overexpression and properties of the recombinant enzyme

Pyridoxal kinase catalyses the phosphorylation of the vitamin B6. A human brain pyridoxal kinase cDNA was isolated, and the recombinant enzyme was overexpressed in E. coli as a fusion protein with maltose binding protein (MBP). Pure pyridoxal kinase exhibits a molecular mass of about 40 kDa when examined by SDS-PAGE and FPLC gel filtration. The recombinant enzyme is a monomer endowed with catalytic activity, indicating that the native quaternary structure of pyridoxal kinase is not a prerequisite for catalytic function. Zn2+ is the most effective divalent cation in the phosphorylation of pyridoxal, and the human enzyme has maximum catalytic activity in the narrow pH range of 5.5-6.0. The Km values for two substrates pyridoxal and ATP are 97 microM and 12 microM, respectively. In addition, the unfolding processes of the recombinant enzyme were monitored by circular dichroism. The values of the free energy change of unfolding (AGo = 1.2 kcal x mol(-1) x K(-1)) and the midpoint transition (1 M) suggested that the enzyme is more stable than ovine pyridoxal kinase against denaturation by guanidine hydrochloride. Intrinsic fluorescence spectra of the human enzyme from red-edge excitation and fluorescence quenching experiments showed that the tryptophanyl residues are not completely exposed and more accessible to neutral acrylamide than to the negatively charged iodide. The first complete set of catalytic and structural properties of human pyridoxal kinase provide valuable information for further biochemical studies on this enzyme.

Red ear(s) syndrome associated with child neuropsychiatric systemic lupus erythematosus

This case illustrates that a child having severe neuropsychiatric systemic lupus erythematosus (NPSLE) with seizure and cerebral vascular disease showed excellent clinical outcome in response to intravenous methylprednisolone and cyclophosphamide pulse, and presented unexplained red ears phenomenon.