Spinocerebellar ataxia type 2 with parkinsonism in ethnic Chinese

OBJECTIVE

To describe the clinical and molecular genetic analysis of a large family of northern Chinese descent with a mutation at the SCA2 locus causing carbidopa-levodopa-responsive parkinsonism.

BACKGROUND

Most causes of parkinsonism remain unknown. However, molecular genetic analysis of families with parkinsonism has recently identified five distinct loci and pathogenic mutations in four of those. Additionally, some of the spinocerebellar ataxia syndromes (SCA), particularly Machado-Joseph syndrome (SCA3), are known to cause parkinsonism. Spinocerebellar ataxia type 2 (SCA2) has not previously been described as causing a typical dopamine-responsive asymmetric PD phenotype.

METHODS

A large family was evaluated clinically and molecularly for apparent autosomal dominant parkinsonism.

RESULTS

The phenotype includes presentation consistent with typical dopamine-responsive parkinsonism. Other presentations in this family include a parkinsonism/ataxia phenotype, which is classic for SCA2 and parkinsonism, resembling progressive supranuclear palsy.

CONCLUSIONS

Patients presenting with a family history of parkinsonism, including familial progressive supranuclear palsy and PD, should be tested for the spinocerebellar ataxia type 2 expansion.

No evidence for association of alpha 1a adrenoceptor gene polymorphism and clozapine-induced urinary incontinence

Clozapine is an effective atypical antipsychotic that has high affinity for many neurotransmitter receptors. Among the adverse effects of clozapine, urinary incontinence is commonly found and is suggested to be caused by alpha-adrenergic blockade. We tested the hypothesis that clozapine-induced urinary incontinence is related to a genetic variant of the alpha(1a)-adrenoceptor. We also tested whether the alpha(1a)-receptor gene confers susceptibility to schizophrenic disorders. Our result indicated that the alpha(1a)-adrenoceptor gene polymorphism investigated plays no major role in the pathogenesis of schizophrenia or in clozapine-induced urinary incontinence. Considering the superior effects of clozapine and its potent adrenergic antagonistic effects, it is of interest to investigate the association between this polymorphism and the treatment response.

Cellular uptake, subcellular localization and photodamaging effect of temoporfin (mTHPC) in nasopharyngeal carcinoma cells: comparison with hematoporphyrin derivative

Temoporfin (meta-tetra (hydroxyphenyl)chlorin; mTHPC) potentiated a 100-fold higher cytotoxic effect than hematoporphyrin derivative (HPD) on two nasopharyngeal carcinoma cell lines (HK1 and CNE2) in terms of the overall photodynamic therapy (PDT) dose. The cellular uptake, evaluated by flow cytometry and spectrophotometry demonstrated that mTHPC exhibited higher uptake ability than HPD. Confocal laser scanning microscopy detection for both the sensitizer and mitochondria probe on the same cell images revealed that both drugs accumulated diffusely in the cytoplasm and that mitochrondria is a target organelle. Photo-activation ruptured the mitochrondria, with more pronounced mitochondrial damage being observed in mTHPC-PDT course. This correlated well with the cell photokilling efficiency of mTHPC.

Apolipoprotein E genotype and schizophrenia

Schizophrenic disorders are complex genetic disorders and may involve multiple genes of small effect. The presence of apolipoprotein E (apoE) is associated with several neuropsychiatric disorders. Previous studies on apoE genotype distribution in schizophrenia have reported conflicting findings. We studied the genotype frequencies in a large group of schizophrenic patients. The genotype distribution was significantly different between the schizophrenic patients and the control subjects. Persons who were sigma3 carriers have an increased risk of schizophrenia. This result suggests that apoE isoforms may play a functional role in the pathogenesis of schizophrenic disorders. Some possible mechanisms regarding the effect of apoE on the development of schizophrenia are discussed.

Upregulation of tyrosine kinase TKT by the Epstein-Barr virus transactivator Zta

The Zta protein is a key transactivator involved in initiating the Epstein-Barr virus (EBV) lytic cascade. In addition to transactivating many viral genes, Zta has the capacity to influence host cellular signals by binding to promoter regions or by interacting with several important cellular factors. Based on the observation that tyrosine kinases play central roles in determining the fate of cells, a kinase display assay was used to investigate whether cells expressing Zta have an altered pattern of kinase expression. The assay revealed that TRK-related tyrosine kinase (TKT) is expressed at significant levels in Zta transfectants but not in control cells. Additional evidence was obtained from Northern and Western blotting. Importantly, the upregulation of phosphorylated TKT and TKT downstream effector matrix metalloproteinase 1 in Zta transfectants hinted that TKT might initiate a signaling cascade in Zta-expressing cells. In addition, deletion analysis of the Zta protein revealed that the transactivation and dimerization domains were both essential for the upregulation of TKT transcription. Moreover, correlation of expression levels of Zta and TKT transcripts in nasopharyngeal carcinoma biopsy specimens was clearly demonstrated by quantitative PCR (Q-PCR), which provides the first evidence for an effect of Zta on cellular gene expression in vivo. These findings offer insight into the virus-cell interactions and may help us elucidate the role of EBV in tumorigenesis.

Subcellular localization of merocyanine 540 (MC540) and induction of apoptosis in murine myeloid leukemia cells

Subcellular localization of photosensitizers is thought to play a critical role in determining the mode of cell death after photodynamic treatment (PDT) of leukemia cells. Using confocal laser scanning microscopy and fluorescent organelle probes, we examined the subcellular localization of merocyanine 540 (MC540) in the murine myeloid leukemia M1 and WEHI 3B (JCS) cells. Two patterns of localization were observed: in JCS cells, MC540 was found to localize on the plasma membrane and mitochondria; and in M1 leukemia cells, MC540 was found to localize on lysosomes. The relationship between subcellular localization of MC540 and PDT-induced apoptosis was investigated. Apoptotic cell death, as judged by the formation of apoptotic nuclei, was observed 4 h after irradiation in both leukemia cell lines. Typical ladders of apoptotic DNA fragments were also detected by DNA gel electrophoresis in PDT-treated JCS and M1 cells. At the irradiation dose of 46 kJ/m2 (LD90 for JCS and LD86 for M1 cells), the percentage of apoptotic JCS and M1 cells was 78 and 38%, respectively. This study provided substantial evidence that MC540 localized differentially in the mitochondria, and the subsequent photodamage of the organelle played an important role in PDT-mediated apoptosis in myeloid leukemia cells.

Infectious Pancreatic Necrosis Virus RNA Cleavage In Vitro by Hammerhead Ribozymes and Enhancement of Ribozyme Catalysis by Oligonucleotide Facilitators

Infectious pancreatic necrosis virus (IPNV), an aquatic birnavirus, has a bisegmented double-stranded RNA genome consisting of a 3.2-kb A segment and a 2.9-kb B segment. To determine the function of IPNV's viral proteins and to study the effects of viral RNA cleavage by hammerhead ribozymes, we cloned and sequenced the IPNV E1S strain of the A segment. After sequencing, we continued to study the virus pathogens inhibited by ribozyme cleavage and analyzed the cleavage of the virus RNA in vitro. The templates (VP2, 1220 bp) for in vitro transcription of S569 and S969 (substrates 569 and 969 bp in length) were synthesized by polymerase chain reaction. The DNA templates of hammerhead ribozymes targeted different sites in the partial sense RNA of IPNV. These templates were chemically synthesized RNAs prepared by runoff transcription of amplification products or synthetic DNA templates containing a T7 RNA polymerase promoter, and were used to characterize several properties of the cleavage reaction at 25 degrees C in 12 mM Mg(2+). Under this condition (25 degrees C, 12 mM Mg(2+)), the hammerhead ribozymes formed an estimated fraction of product during the reaction of only 30% in cleaving long RNA substrates in vitro. Short DNA facilitators (12 or 24-mers) that bind adjacent to either the 3' or 5' end of the ribozyme enhanced the rate of cleavage of the long RNA substrates containing 569 and 969 nucleotides, respectively, in trans. The hammerhead ribozymes with 3'-end facilitators reacted more efficiently (i.e., 65%).

Norepinephrine modulates single hypothalamic arcuate neurons via alpha(1)and beta adrenergic receptors

The effects of norepinephrine (NE) on the electrophysiological activities of single hypothalamic arcuate neurons were studied using extracellular recording of 385 neurons from 169 brain slices in rats. The results showed that: (1) of 236 neurons selected randomly and tested with NE application, 137 (58.0%) were excited, 67 (28.4%) were inhibited, and 32 (13.6%) failed to respond; (2) substitution of low Ca(2+)-high Mg(2+) artificial cerebrospinal fluid (ACSF) for normal ACSF abolished the NE-induced inhibitory effect but failed to abolish the excitatory effect; (3) both the NE-induced excitatory and inhibitory effects were antagonized partly by phentolamine, prazosin, and propranolol but not by yohimbine; (4) naloxone and glibenclamide, a blocker of adenosine triphosphate-sensitive (K(ATP)) channels, blocked the NE-induced inhibitory effect; and (5) neurons that were inhibited by NE were also inhibited by morphine and cromakalim, an agonist of K(ATP) channels, and moreover, the morphine-induced inhibitory effect could be blocked by glibenclamide, while the cromakalim-induced inhibitory effect was not blocked by naloxone. These results imply that: (a) NE excites arcuate neurons through a mechanism that is insensitive to lowering the extracellular Ca(2+) suggesting a direct postsynaptic response through alpha(1)- and beta-adrenergic receptors, while NE inhibits cells through at least an inhibitory interneuron in arcuate and so is dependent on a Ca(2+)-sensitive presynaptic release mechanism; and (b) the inhibitory interneuron may be opioidergic, being excited first through alpha(1)- and beta-adrenergic receptors, after which the released opioids inhibit the neurons being recorded with an involvement of activation of K(ATP) channels. This possibility needs to be substantiated in much more detail.

Expression of the Epstein-Barr virus BHRF1 gene, a homologue of Bcl-2, in nasopharyngeal carcinoma tissue

Epstein-Barr virus (EBV) infection is associated closely with the pathogenesis of nasopharyngeal carcinoma (NPC). The EBV gene product, BHRF1, has been demonstrated in vitro and is structurally and functionally similar to the oncogene bcl-2, that is able to protect cells from programmed cell death. To determine whether the BHRF1 gene is expressed in vivo, BHRF1 mRNA or protein were sought in tissues from NPC and non-NPC patients. BHRF1 transcripts were specifically detected in the NPC tumours (32 out of 44, 72.7%) rather than the non-NPC tissues (0 out of 25) by reverse transcription, polymerase chain reaction and Southern hybridization. Other EBV genes, such as the lytic gene BZLF1 and latent genes EBNA1 and LMP2A, were also investigated. BZLF1 transcripts also were found specifically in NPC tumours (33 out of 44, 75%). EBNA1 was expressed in 79.5% of NPC, and 28% of non- NPC, tissues and LMP2A was expressed in 70.5% of NPC, and 88% of non-NPC, tissues. BHRF1 protein was detected by immunohistochemistry in 4 metastatic NPC, of 36 NPC tissue sections available. The BHRF1 protein was distributed in both the nucleus and cytoplasm of the neoplastic epithelial cells. IgG antibody against the BHRF1 protein was detected in 6 of 17 (35. 3%) NPC plasma, but the protein and IgG were both absent from the non-NPC controls. BHRF1 DNA sequences were determined for 11 NPC and 3 non-NPC samples. No sequence was specific for the EBV isolates from NPC tissue. Amino acids 79 and 88 always appeared in the same form, however, for every tested isolate and both were valine or leucine. This particular characteristic was not present in the B95-8 strain or in the corresponding regions of homologues, Bcl-2 and Bcl-XL, and was regarded as unique to Oriental EBV strains.

Sonographic features related to volvulus in neonatal intestinal malrotation

This 3 year prospective study evaluated the sensitivity and specificity of abdominal ultrasonography and color Doppler ultrasonography in 31 neonates with suspected malrotation or malrotation with volvulus. Water instillation was used to detect duodenal dilatation, edema, and malrotated bowels. Twenty patients with ultrasonographic characteristics of inversion of the superior mesenteric artery and superior mesenteric vein were later surgically proved to have malrotation. Nine of these 20 patients also had volvulus. Sonographic features suggestive of volvulus included duodenal dilation with tapering configuration (8 of 9 cases, 89%), fixed midline bowel (8 of 9 cases, 89%), whirlpool sign (8 of 9 cases, 89%), and dilation of the distal superior mesenteric vein (5 of 5 cases, 100%). The sensitivity and specificity of duodenal dilation with tapering configuration for detecting volvulus were 89% and 92%, respectively; of fixed midline bowel, 89% and 92%; of whirlpool sign, 89% and 92%; and of dilation of distal superior mesenteric vein, 56% and 73%. The results of this study indicate that ultrasonographic features of inversion of the superior mesenteric artery and superior mesenteric vein could aid in the diagnosis of malrotation, and certain sonographic features can also be used to evaluate volvulus, a condition requiring emergent operation.

Relationship of serum lactate dehydrogenase, creatine kinase, aspartate aminotransferase concentrations and severe intraventricular hemorrhage/leukomalacia in very low birth body weight preterm neonates

Estimations of serum enzyme values are widely employed as valuable diagnostic aids in diseases. Most commonly employed enzymes include Aspartate aminotransferase (AST), Lactate dehydrogenase (LDH), and Creatine kinase (CK). The study was designed to determine the relationship of elevated postnatal serum LDH, CK, and AST concentrations within the first day of life and the risk of suffering severe intraventricular hemorrhage (IVH) and/or periventricular leukomalacia (PVL) in VLBW preterm newborns. 81 preterm neonates whose birth body weight < 1500 gm were enrolled. Serums were obtained for measurement within the first postnatal day. Cranial ultrasound scans were performed twice per week after birth until their body weight was above 2300 gm or postconceptional age above 40 weeks. Significant difference was noted in serum LDH and CK concentrations in severe IVH/PVL infants (p < 0.05). No difference was found in serum AST values. Compared with the cut-off values of 1933 IU/L of LDH concentration and 652 IU/L of CK, the predictive values revealed a sensitivity, specificity, negative predictive value and positive predictive value of 76.9%, 89.7%, 95.3% and 58.8%, respectively. In conclusion, higher serum LDH and/or CK concentrations within the first day of life were associated with risk for development of severe IVH/PVL.

Precambrian animal diversity: putative phosphatized embryos from the Doushantuo Formation of China

Putative fossil embryos and larvae from the Precambrian phosphorite rocks of the Doushantuo Formation in Southwest China have been examined in thin section by bright field and polarized light microscopy. Although we cannot completely exclude a nonbiological or nonmetazoan origin, we identified what appear to be modern cnidarian developmental stages, including both anthozoan planula larvae and hydrozoan embryos. Most importantly, the sections contain a variety of small (</=200 microm) structures that greatly resemble gastrula stage embryos of modern bilaterian forms.

Photocytotoxic and DNA damaging effect of temoporfin (mTHPC) and merocyanine 540 (MC540) on nasopharyngeal carcinoma cell

Photodynamic therapy (PDT) is a new approach to cancer treatment for a variety of malignant tumors. In this study, two clinical photosensitizers, Temoporfin (meta-tetra-hydroxyl-phenyl-chlorin; mTHPC) and merocyanine 540 (MC540), were selected to explore for their photocytotoxic and genotoxic effects on nasopharyngeal carcinoma cells (NPC/HK1 and CNE2). Results of tetrazolium reduction assay showed that 80% cell killing were achieved for both cell lines at 0.4 microg/ml mTHPC for 24 h incubation and then with 40 kJ/m2 light irradiation, whereas 40 microg/ml MC540 with 50 kJ/m2 light dosage was required to attain the same level of phototoxicity for NPC/HK1. On the contrary, NPC/CNE2 was quite resistant to MC540. Hence, mTHPC-mediated PDT exerted a more potent effect than MC540-mediated PDT, even though the molar extinction coefficient of the main absorption peak for MC540 is much higher than that of mTHPC. Dark cytotoxicity remained negligible for both sensitizers. Comet assay was used to evaluate the DNA strand break and potential genotoxic effect induced by mTHPC and MC540 on the NPC cells. No DNA strand break was detected in the absence of light, and under sublethal treatment (LD25) for either sensitizer-loaded cells. Confocal laser scanning microscopy showed that mTHPC and MC540 localized in the cytoplasm but not in the nucleus of the tumor cells, which provided evidence for undetectable DNA damage under dark and low photodynamic dose.

A protein kinase activity associated with Epstein-Barr virus BGLF4 phosphorylates the viral early antigen EA-D in vitro

The Epstein-Barr virus (EBV) open reading frame BGLF4 was identified as a potential Ser/Thr protein kinase gene through the recognition of amino acid sequence motifs characteristic of conserved regions within the catalytic domains of protein kinases. In order to investigate this potential kinase activity, BGLF4 was expressed in Escherichia coli and the purified protein was used to generate a specific antiserum. Recombinant vaccinia virus vTF7-3, which expresses the T7 RNA polymerase, was used to infect 293 and 293T cells after transient transfection with a plasmid containing BGLF4 under the control of the T7 promoter. Autophosphorylation of the BGLF4 protein was demonstrated using the specific antiserum in an immune complex kinase assay. In addition, EBNA-1-tagged BGLF4 and EBNA-1 monoclonal antibody 5C11 were used to demonstrate the specificity of the kinase activity and to locate BGLF4 in the cytoplasm of transfected cells. Manganese ions were found to be essential for autophosphorylation of BGLF4, and magnesium can stimulate the activity. BGLF4 can utilize GTP, in addition to ATP, as a phosphate donor in this assay. BGLF4 can phosphorylate histone and casein in vitro. Among the potential viral protein substrates we examined, the EBV early antigen (EA-D, BMRF1), a DNA polymerase accessory factor and an important transactivator during lytic infection, was found to be phosphorylated by BGLF4 in vitro. Amino acids 1 to 26 of BGLF4, but not the predicted conserved catalytic domain, were found to be essential for autophosphorylation of BGLF4.

Salivary and serum antibody response to Streptococcus mutans antigens in humans

Humoral immunity against Streptococcus mutans infection was analyzed in caries-active and caries-free young adults by immunoblotting. All volunteers from both groups had detectable salivary immunoglobulin A (IgA) and serum IgG antibodies, with similar profiles. They could be classified on the basis of relative intensity of the immunoblot bands into categories of high or low responders. Common protein antigens with molecular weight ranging from approximately 45 to 190 kDa could be found either extracellularly or associated with the cell wall of S. mutans cultured in vitro. The predominant reactive antigens recognized by both IgA and IgG were of proteins around 63 and 60 kDa. Detection of IgA antibodies to the various antigens of S. mutans in individual saliva samples did not always correlate with serum IgG antibody profiles. In addition, distinct bands, which reacted preferentially with either IgA or IgG, could be detected by antibodies from specific subjects. Differential reactivities of salivary IgA and serum IgG antibodies to two, cell-wall associated protein antigens around 33 and 36 kDa were found in caries-active and caries-free young adults; 30.8% of caries-free subjects and 12% of caries-active subjects (P < 0.01) exhibited detectable antibody response to these antigens. This difference was not attributable to variations in antibody levels, since antibody response to these proteins were still detectable in some caries-free but not caries-active individuals whose levels of antibodies to other antigens were low. Thus, a new antibody profile which correlates with dental caries disease activity has been identified in a selected population. Differences in mucosal and systemic immune responses to S. mutans seem to be both antigen and host dependent.

Identification of a fibronectin binding protein from Streptococcus mutans

The interaction of viridans streptococci with components of the extracellular matrix (ECM) plays an important role in the pathogenesis of infective endocarditis. We have identified a surface protein of Streptococcus mutans which binds the ECM constituent fibronectin (Fn). Initially, we found that S. mutans could adsorb soluble Fn in plasma, but with lower efficiency than Streptococcus pyogenes. In addition, S. mutans could bind immobilized Fn in a dose-dependent manner when tested using an enzyme-linked immunosorbent assay. Crude extracts of cell wall-associated proteins or extracellular proteins from S. mutans MT8148 specifically bound Fn through a protein with the molecular mass of ca. 130 kDa, as detected by far-Western immunoblotting. The candidate Fn binding protein (FBP-130) was purified to near homogeneity by using Fn coupled Sepharose 4B affinity column chromatography. A rabbit polyclonal antibody against FBP-130 reacted specifically with a protein of molecular mass of ca. 130 kDa in both cell wall and extracellular fractions, and the abundance of FBP was higher in the former than in the latter fractions. The purified FBP bound specifically to immobilized Fn, whereas the binding of soluble Fn to coated FBP could only be detected in the presence of high concentrations of Fn. The purified FBP, as well as anti-FBP immunoglobulin G, inhibited the adherence of S. mutans to immobilized Fn and endothelial cells (ECV304) in a dose-dependent manner. These results demonstrated that FBP-130 mediated the adherence of S. mutans specifically to Fn and endothelial cells in vitro. The characteristics of S. mutans and FBP-130 in binding Fn confirmed that viridans streptococci adopt different strategies in their interaction with ECM.

Temporary hearing impairment after general anesthesia--a case report

The incidence of hearing impairment after anesthesia is rare. We report a case who received left total knee and hip replacement and developed severe hearing impairment of the left ear after general anesthesia. Examination of the left ear by an otolaryngologist showed that there was no noticeable abnormality. The hearing acuity recovered gradually and returned to normal 3 days later. The use of nitrous oxide during anesthesia was incriminated as the possible cause.

A novel EBNA-1 tag system for high level expression and efficient detection of fusion proteins in vitro and in vivo

A highly specific monoclonal antibody, which recognises an epitope between amino acids (aa) 408 and 446 of EBNA-1, was found to immunoprecipitate this protein with great efficiency. By adding a 39-aa tag, the BGLF4 protein product of EBV was shown to express in the cytoplasm of transfected cells. This EBNA-1 tag could be used for the detection of specific protein expression by immunoblotting, immunofluorescence and, especially, immunoprecipitation assays. A plasmid vector encoding this EBNA-1 tag sequence was therefore designed for efficient expression both in vitro and in vivo. The efficient translational start signal of black beetle virus (BBV) was placed under the control of the SV40 or T7 promoters, and the beta-globin splicing signal used to enhance the transportation of mRNA from the nucleus to the cytoplasm.

Clinical and epidemiological implications of swine hepatitis E virus infection

In nonendemic areas, most patients with acute hepatitis E were infected through traveling to endemic areas. However, some patients did not have a history of foreign travel before infection. Furthermore, high seroprevalence rates of antibody to hepatitis E virus (anti-HEV) were found in the general adult population in some countries without any recorded outbreak of hepatitis E. The significance of anti-HEV assay in these subjects remains obscure. To study if swine might be a source of HEV infection, HEV was tested in sera of 235 pigs in Taiwan, and from 5 patients with acute HEV infection who either denied or did not provide any foreign travel history. Three (1.3%) pigs had detectable swine HEV RNA. The swine and human HEV strains from Taiwan formed a monophyletic group, distinct from three previously reported groups: the United States human and swine HEV strains, the Mexico strain, and the largest group composed of the Asian and the African strains. The identity of nucleotide sequences was 84-95% between swine and human HEV strains in Taiwan, and 72-79% between Taiwan strains and those from different areas. The predicted amino acid sequence of a Taiwan swine HEV strain within the peptide 3-2 used in commercial anti-HEV assay showed a high identity (91-94%) with those of other human and swine HEV strains. Swine may be a reservoir of HEV and subclinical swine HEV infection may occur. Cross-reactivity of current anti-HEV assay may account for the high prevalence rate of anti-HEV in the general population in nonendemic areas.

Hierarchical browsing and search of large image databases

The advent of large image databases (>10000) has created a need for tools which can search and organize images automatically by their content. This paper focuses on the use of hierarchical tree-structures to both speed-up search-by-query and organize databases for effective browsing. The first part of this paper develops a fast search algorithm based on best-first branch and bound search. This algorithm is designed so that speed and accuracy may be continuously traded-off through the selection of a parameter lambda. We find that the algorithm is most effective when used to perform an approximate search, where it can typically reduce computation by a factor of 20-40 for accuracies ranging from 80% to 90%. We then present a method for designing a hierarchical browsing environment which we call a similarity pyramid. The similarity pyramid groups similar images together while allowing users to view the database at varying levels of resolution. We show that the similarity pyramid is best constructed using agglomerative (bottom up) clustering methods, and present a fast sparse clustering method which dramatically reduces both memory and computation over conventional methods.

Identification of a novel mouse p53 target gene DDA3

We have identified a novel p53 regulated gene designated DDA3 through differential mRNA display on IW32 erythroleukemia cells containing a temperature sensitive p53 allele, tsp53val-135. DDA3 mRNA induction could be observed in all sublines expressing tsp53val-135 cultured at permissive temperature as well as in NIH3T3 cells undergoing DNA damage. Upregulation of DDA3 could be detected within 2 h after down-shifting the temperature to 32.5 degrees C; upon shifting back to 38.5 degrees C, DDA3 mRNA rapidly degraded with a half-life of less than 2 h. Actinomycin D, but not cycloheximide, inhibited the p53 dependent DDA3 induction, suggesting that the activation is through transcriptional regulation and does not require de novo protein synthesis. DDA3 was expressed in multiple mouse tissues including brain, spleen, lung, kidney and testis. Full-length DDA3 cDNA was cloned and it contained an open reading frame predicted to encode a proline rich protein of 329 amino acids. Overexpression of DDA3 in H1299 lung carcinoma cells suppressed colony formation. These results suggest that DDA3 is a p53-regulated gene that might participate in the p53-mediated growth suppression.

Acute fatal vasoplegia and asystole induced by intravenous amiodarone after cardiopulmonary bypass in a patient with preoperative cardiogenic shock

Single dose intravenous amiodarone has been widely used and shown to be effective to treat supraventricular and ventricular arrhythemias in cardiac surgery. We, herein, report a 60-year-old female patient, sustaining cardiogenic shock in the course of percutaneous transluminal coronary angioplasty (PTCA) for unstable angina unrelieved by medication including nitroglycerin, succumbed to a life-saving emergent coronary artery bypass grafting (CABG) operation at the end of cardiopulmonary bypass (CPB) following a 180 mg bolus dose of amiodarone (3 mg/kg) directed at the ventricular arrhythmias, triggered by protamine and unresponsive to lidocaine treatment. Amiodaroneinduced asystole and vasoplegia were thought to be the causation of the failure of resuscitation. The causes of the development of these complications, the potential hazards of its use and the management relative to the consequential complications are reviewed and discussed.