Peptide and major histocompatibility complex-specific breaking of humoral tolerance to native insulin with the B9-23 peptide in diabetes-prone and normal mice

NOD mice spontaneously develop anti-insulin autoantibodies and diabetes. A dominant peptide recognized by T-cell clones from NOD mice is insulin B-chain peptide B9-23. When administered subcutaneously to NOD mice, this peptide decreases the development of diabetes. In this study, we evaluated the autoantibody response to native insulin after administration of the B9-23 peptide. In NOD mice, administration of the B9-23 peptide in incomplete Freund's adjuvant enhanced their insulin autoantibody response with a higher level and longer persistence. Induction of insulin autoantibodies with the B9-23 peptide was observed in non-diabetes-prone BALB/c mice and NOR mice within 2 weeks of administration, but this was not observed in C57BL/6 mice. A series of A-chain, other B-chain, and proinsulin peptides did not induce insulin autoantibodies. Induced anti-insulin autoantibodies could not be absorbed with the peptide alone but could be absorbed with native insulin. The B13-23 peptide (one of two identified epitopes within B9-23) when administered to BALB/c mice, induced autoantibodies, whereas peptide B9-16 did not. Induction of autoantibodies mapped to the major histocompatibility complex (MHC) rather than to the background genes. Both splenocytes with I-A(d)/I-E(d) or I-A(g7)/I-E(null) presented the B9-23 peptide to NOD islet-derived T-cell clones. Finally, administration of the B9-23 peptide to BALB/c mice, even without adjuvant, could induce insulin autoantibodies. Our results indicate that B-cell tolerance to intact insulin is readily broken with the presentation of the B9-23 insulin peptide, depending on the host's specific MHC.

Structure of the N-terminal region of Haemophilus influenzae H10017: implications for function

Haemophilus influenzae is a gram-negative pathogen that causes infections ranging from asymptomatic colonization of the human upper respiratory tract to serious invasive diseases such as meningitis. Although the genome of Haemophilus influenzae has been completely sequenced, the structure and function of many of these proteins are unknown. H10017 is one of these uncharacterized proteins. Here we describe the three-dimensional solution structure of the N-terminal portion of H10017 as determined by NMR spectroscopy. The structure consists of a five-stranded antiparallel beta-sheet and two short alpha-helices. It is similar to the C-terminal domain of Diphtheria toxin repressor (DtxR). The C-terminal portion of H10017 has an amino acid sequence that closely resembles pyruvate formate-lyase--an enzyme that converts pyruvate and CoA into acetyl-CoA and formate by a radical mechanism. Based on structural and sequence comparisons, we propose that the C-terminus of H10017 functions as an enzyme with a glycyl radical mechanism, while the N-terminus participates in protein/protein interactions involving an activase (iron-sulfur protein) and/or the substrate.

Mutation analysis and the correlation between genotype and phenotype of Arg778Leu mutation in chinese patients with Wilson disease

BACKGROUND

The defective gene (ATP7B) that causes Wilson disease (WD) codes for a putative copper-transporting P-type adenosine triphosphatase. After cloning of ATP7B, the spectrum of mutations and their clinical consequences have been investigated in patients with WD in different ethnic populations. However, the spectrum of mutations and the correlation of genotype-phenotype in the Chinese population have not been extensively studied.

OBJECTIVE

To investigate the characterization of mutations of ATP7B and the correlation between genotype and phenotype in the Chinese population.

METHODS

We studied 60 unrelated healthy Chinese and 65 unrelated Chinese families, including 84 patients with WD and 126 parents. Genomic DNA was prepared from peripheral blood leukocytes using a salt-precipitation method. Polymerase chain reaction single-strand conformation polymorphism and subsequent direct sequencing were used to identify the mutations and polymorphisms of ATP7B. Statistical analysis was performed using t test or chi(2) test.

RESULTS

We identified 18 mutations (7 novel) and 11 polymorphisms (3 novel). The novel mutations are -36C-->T, Trp650ter, Gln914ter, 2810delT, Thr935Met, Arg1041Pro, and Glu1173Lys. The novel polymorphisms are 1168A-->G (Ile390Val), 2785A-->G (Ile929Val), and 3316G-->A (Val1106Ile). Two mutations, Arg778Leu and Thr935Met, are relatively frequent, representing 37.7% and 10.0% of patients, respectively. To our knowledge, we are the first to report the correlation between the genotype and phenotype of Arg778Leu. The result shows that Arg778Leu homozygotes are associated with the early onset of WD with hepatic presentation.

CONCLUSIONS

The Arg778Leu and Thr935Met mutations are hot spots in the Chinese population. The features of mutations of ATP7B differ between the Chinese and Western ethnic populations. The Arg778Leu mutation has severe effects on the function of ATP7B. These findings are valuable for developing a fast and effective method to diagnose the presence of the WD gene.

[Auricular cartilage palisade technique for repairing tympanic membrane perforation]

OBJECTIVE

To study the auricular cartilage palisade technique for repairing tympanic membrane perforation.

METHOD

Sixty-six cases of large tympanic membrane perforation were treated with auricular cartilage. The results were compared with that of temporal fascia repairing in 60 ears.

RESULTS

The closure rates of tympanic membrane perforation were 92.4% in cartilage group and 80% in temporal fascia group, respectively. There was no significant difference between two groups in hearing improvement. The cartilage is quite suitable for repairing large perforation of the tympanic membrane and for treating adhesive otitis media.

CONCLUSION

The auricular cartilage palisade technique is an ideal method for repairing tympanic membrane perforation.

Sexual differences and estrous cycle in methamphetamine-induced dopamine and serotonin depletions in the striatum of mice

Four consecutive doses (10 mg/kg) of methamphetamine, s.c., produced a substantial striatal dopamine depletion in both sexes of BALB/c and C57BL/6J mice. Male C57BL/6J mice exhibited greater dopamine depletions in the striatum compared to female C57BL/6J mice. In contrast, male and female BALB/c mice demonstrated an equivalent magnitude of striatal dopamine depletion. Regardless of sex, C57BL/6J mice demonstrated approximately 1.4 to 2.2 times greater dopamine depletions in the striatum compared to BALB/c mice. Moreover, methamphetamine caused 4 times greater serotonin depletions in male as opposed to female BALB/c mice while sparing either sex of the C57BL/6J mice. Furthermore, female mice of both strains appeared to have the greatest basal dopamine levels during proestrus and the lowest basal dopamine levels during diestrus. Likewise, female mice of both strains exhibited the lowest dopamine depletions in the striatum when the dosing regimen of methamphetamine started at proestrus whereas the greatest dopamine depletions in the striatum occurred when the regimen started during diestrus. These results suggest that sex hormones and other modulating factors may play a role in methamphetamine-induced dopamine and serotonin neurotoxicity.

Amorphous pharmaceutical solids: preparation, characterization and stabilization

The importance of amorphous pharmaceutical solids lies in their useful properties, common occurrence, and physicochemical instability relative to corresponding crystals. Some pharmaceuticals and excipients have a tendency to exist as amorphous solids, while others require deliberate prevention of crystallization to enter and remain in the amorphous state. Amorphous solids can be produced by common pharmaceutical processes, including melt quenching, freeze- and spray-drying, milling, wet granulation, and drying of solvated crystals. The characterization of amorphous solids reveals their structures, thermodynamic properties, and changes (crystallization and structural relaxation) in single- and multi-component systems. Current research in the stabilization of amorphous solids focuses on: (i) the stabilization of labile substances (e.g., proteins and peptides) during processing and storage using additives, (ii) the prevention of crystallization of the excipients that must remain amorphous for their intended functions, and (iii) the selection of appropriate storage conditions under which amorphous solids are stable.

Novel methylation targets in de novo acute myeloid leukemia with prevalence of chromosome 11 loci

Aberrant DNA methylation is believed to be important in tumorigenesis by causing either transcriptional inactivation of genes or chromosomal instability. Several laboratories have identified promoter hypermethylation of tumor suppressor genes in acute myeloid leukemia (AML). However, these studies do not provide a global assessment of overall methylation changes and do not allow the identification of novel methylated sequences. Previously, nonrandom CpG island methylation was reported in 17 adult de novo AML diagnostic samples when compared with the corresponding remission samples by means of restriction landmark genomic scanning (RLGS). That study has been expanded on by an analysis of a larger set of CpG islands (1740 vs 1184), which now provides details of 33 cloned methylated loci, including 21 known genes or expressed sequence tags. Five of these cloned loci appear to be methylated only in AML and not in the 6 solid tumors studied in this study (more than 98 samples analyzed). Chromosomal location was available for 30 of the 33 loci, and 5 of these 30 (17%) are localized to chromosome 11, suggesting a trend toward overrepresentation of methylation events on this chromosome. These results provide evidence for widespread aberrant methylation in AML, with identification of novel methylation targets, epigenetic changes that appear unique to AML, and apparent preferential methylation on chromosome 11.

TerplexDNA gene carrier system targeting artery wall cells

The development of non-viral gene carrier systems becomes more urgent and important due to the major biosafety considerations involved with application of viral vector systems for clinical gene therapy. We recently developed a novel non-viral gene carrier system, termed TerplexDNA, which showed high gene transfer efficiency when compared to the lipofectamine gene delivery system both in HepG2 and A7R5 cell lines in vitro. In present studies, we demonstrated that the TerplexDNA gene carrier system specifically delivered the reporter genes (LacZ and Luciferase) and therapeutic gene (hrVEGF(165) cDNA) into bovine aortic artery wall cells (endothelial cells and smooth muscle cells) by receptor mediated endocytosis. We found that the transfection efficiency to these primary artery wall cells, when mediated by the TerplexDNA system, was dose-dependent, saturable and was significantly inhibited by excess free LDL. The transfection efficiency of the TerplexDNA gene carrier system was approximately 60-fold higher than that of the lipofectamine gene carrier system. The TerplexDNA gene carrier system is a useful and promising tool for artery wall gene transfer.

[beta-elemene induces apoptosis of K562 leukemia cells]

OBJECTIVE

To investigate the apoptosis-inducing effect of beta-elemene on K562 leukemia cells.

METHODS

Hoechst 33342 and PI fluorescence staining, DNA fragmentation, electron microscopy, flow cytometry, and immunocytochemistry were used to evaluate the effect of beta-elemene on K562 cells.

RESULTS

beta-elemene heatment induced the formation of apoptotic bodies and DNA ladder. The effect was dose- and time-dependent. The expression of bcl-2 was decreased in beta-elemene treated cells as compared with the untreated control cells.

CONCLUSION

beta-elemene exerts its cytotoxic effect on K562 leukemic cells by the induction of apoptosis.

Iterative algorithm with a constraint condition for numerical reconstruction of a three-dimensional object from its hologram

A novel method to obtain the three-dimensional mathematical model of a transparent object from its hologram is presented. The proposed method can numerically extract the object information from the fringe pattern of the hologram. Then an iterative algorithm is used to imitate an imaging system by focusing on different layers of the object; and by operating in both the spatial domain and the frequency domain, the algorithm produces a series of two-dimensional layer images. The object is finally reconstructed layer by layer. A constraint condition should be satisfied, and the noise distribution can be rearranged in different reconstruction cycles so as to get better reconstruction quality. Numerical simulations have proved the effectiveness of the proposed method.

Androgen metabolism in regenerating liver of male rats: evidence for active uptake and utilization of testosterone

The role of androgen in the regenerative process of the liver remains unclear. Male Sprague-Dawley rats were subjected to either 70% hepatectomy or sham operation. Immediately after surgical procedures, rats were injected with 0.3 µCi/g of body weight [3H]-testosterone from the inferior vena cava. The radioactivities of the remnant liver were counted for 0-24 h. For measurement of sex hormones and their metabolizing enzymes activities in the regenerating liver, the same experiments were also conducted, in which the rats were sacrificed up to 120 h. The plasma and hepatic testosterone, dihydrotestosterone(DHT) and estradiol were determined by radioimmunoassays. Uptake of [3H]-testosterone in the regenerating liver was significantly higher during the first 6 h. 5alpha-reductase I and DHT were increased in parallel to the hepatocyte proliferation which was assessed by proliferating cell nuclear antigen (PCNA) labeling index. On the other hand, hepatic 3alpha-hydroxysteroid dehydrogenase level did not alter but aromatase activity significantly decreased after 70% hepatectomy. These results suggest that during the early phase of liver regeneration, testosterone was actively uptaken from the plasma by the regenerating liver and was converted into DHT by elevated hepatic 5alpha-reductase enzyme. Thus androgens might play a crucial role in liver regeneration.

[Study on antitumor effect and mechanism of aloe polysaccharides]

OBJECTIVE

To study the antitumor activity and mechanism of aloe polysaccharides (AP).

METHODS

AP was administered i.p. or i.v. to Sarcoma 180(S180) bearing mice or Hepatoma22(H22) bearing mice solely or combining with CTX, FU and ADM respectively. 10 days later, for S180 mice, the blood was analyzed, the tumor was peeled off and weighed, and the spleen index, thymus index was calculated. For H22 bearing mice, the survival rate was observed or the IL-2, TNF content in serum was tested.

RESULTS

25 mg/kg.d or 50 mg/kg.d AP group could evidently reduce the tumor weight of S180 bearing mice and prolong the survival time of H22 bearing mice. AP also could improve the antitumor effects of CTX, ADM, FU, and lessen the chemotherapy side-effects. Furthermore, AP could improve the level of IL-2, TNF in the serum of mice bearing S180 or H22.

CONCLUSION

AP has the effects of antitumor, enhancing the antitumor activity of chemotherapy drugs and lessening their side-effects. This effect was possibly derived from inducing IL-2 and TNF producing in body and improving the immunity activity.

Cloning and Characterization of Human and Mouse Mitochondrial Elongation Factor G, GFM and Gfm, and Mapping of GFM to Human Chromosome 3q25.1–q26.2

Similar to the translational system in the cell cytoplasm, the initiation, elongation, and termination of protein synthesis in the mitochondria of eukaryotes are catalyzed by several protein factors. These factors, from the viewpoint of evolution, are more closely related to the corresponding prokaryotic factors than to those in the eukaryotic cytoplasm. In this paper, we isolated two cDNAs coding for human and mouse mitochondrial elongation factor G (GFM and Gfm, respectively). The GFM cDNA, which is 3481 bp in length, predicts a protein of 751 amino acids sharing 84 and 42% identity and 88 and 62% similarity to rat EF-G(mt) and Escherichia coli EF-G, respectively, and 24% identity and 39% similarity to human EF-2, the equivalent of EF-G in the cytoplasm. The mouse Gfm cDNA is 2564 bp and contains an intact open reading frame that encodes 751 amino acids showing 89% sequence identity and 94% similarity to human GFM. Northern blot analysis of human GFM revealed three transcripts of 3.8, 3.4, and 2.9 kb. The first two were expressed at high levels in heart, skeletal muscle, and testis, at moderate levels in liver and kidney, and at low levels in other tissues including brain, placenta, and lung, while the last transcript was expressed only in testis. The relative abundance of GFM was consistent with the observations for human EF-Tu(mt) and EF-Ts(mt), the other two mitochondrial elongation factors, indicating that the three factors were expressed at corresponding levels. The expression pattern of mouse Gfm was also determined, which showed that Gfm was expressed as a 3.0-kb transcript, abundantly in heart, skeletal muscle, kidney, and testis. In addition, GFM was assigned to human chromosome 3q25.1-q26.2 by the radiation hybrid mapping method. The genomic organization of GFM was also analyzed by comparing this cDNA with a genomic DNA sequence (Accession No. AC010936), which showed that GFM contained 18 exons and spanned at least 40 kb.

Metal-insulator crossover in superconducting cuprates in strong magnetic fields

The metal-insulator crossover of the in-plane resistivity upon temperature decrease, recently observed in several classes of cuprate superconductors, when a strong magnetic field suppresses the superconductivity, is explained using the U(1)xSU(2) Chern-Simons gauge field theory. The origin of this crossover is the same as that for a similar phenomenon observed in heavily underdoped cuprates without magnetic field. It is due to the interplay between the diffusive motion of the charge carriers and the "peculiar" localization effect due to short-range antiferromagnetic order. We also calculate the in-plane transverse magnetoresistance which is in fairly good agreement with available experimental data.

Rapid intravenous administration of amino acids prevents biliary sludge induced by total parenteral nutrition in humans

The aim of this study was to evaluate whether daily rapid intravenous administration of amino acids (IVAA) prevented the formation of biliary sludge in humans receiving long-term total parenteral nutrition (TPN). Thirty adult patients receiving TPN for more than 28 consecutive days were studied. They were randomized to receive either saline solution (placebo) intravenously (15 patients) or 6.9% branched chain amino acid (BCAA)-enriched amino acid (15 synthetic amino acids; Freamine HBC) solution given by administration rapid intravenous (15 patients). The groups were similar with respect to age, sex, diagnosis, liver function test results, amylase levels, TPN time, and time of study. All patients underwent weekly ultrasound studies. Volume and emptying studies of the gallbladder in response to the study drug were performed after 1 week. As a result, none of the patients receiving rapid IVAA had sludge, whereas 11 of the 15 patients receiving placebo had sludge (P < 0.01). Results of emptying studies showed significant contraction of the gallbladder in those in the rapid IVAA group, but not in the placebo group. Consequently, the data suggest that rapid IVAA given daily prevents TPN-induced stasis and sludge in the gallbladder. We conclude that rapid IVAA should be used as routine prophylaxis against biliary sludge and formation of gallstones in patients receiving long-term TPN.

Characterization of three infectious bronchitis virus isolates from China associated with proventriculus in vaccinated chickens

Outbreaks of an avian disease in infectious bronchitis-vaccinated chickens in China have led to the characterization of coronaviral isolates Q1, J2, and T3, which were isolated from proventricular tissues of the affected young layer flocks. Serologic analysis revealed that they could induce high titers of infectious bronchitis virus (IBV) antibodies in inoculated specific-pathogen-free (SPF) chickens in indirect enzyme-linked immunosorbent assay but were not neutralized by antisera specific to the IBV serotype M41 and the Australian T strain. In a pathogenicity experiment, the clinical signs and related gross lesions resembling those of field outbreaks were reproduced in SPF chickens, and viruses were reisolated from the damaged tissues, including trachea, proventriculus, duodenum, and cecal tonsil. Sequence data demonstrated the complete S1 amino acid sequences of these isolates were almost identical despite recovery from geographically different areas in China and had 47.3%-82.3% similarity in comparison with the 47 published S1 sequences. On the basis of genotyping and limited serology, the three isolates, which were responsible for field outbreaks of the disease, might be a new IBV variant.

Study of protection by recombinant fowl poxvirus expressing C-terminal nucleocapsid protein of infectious bronchitis virus against challenge

A stable recombinant fowl poxvirus (rFPV) expressing the C-terminal region (119 amino acids) of the nucleocapsid (N) protein of an infectious bronchitis virus (IBV) strain Ch3 was constructed by inserting the coding sequence within the thymidine kinase gene of fowl poxvirus (FPV) by homologous recombination. The N protein was expressed under control of the vaccinia virus promoter P7.5 in chicken embryo fibroblast cell cultures as seen in immunofluorescence assay and in rFPV-inoculated specific-pathogen-free (SPF) chickens by detecting antibodies with enzyme-linked immunosorbent assay (ELISA). A homologous IBV strain (Ch3) and two heterologous IBV strains (Ch5 and H4) were used to inoculate SPF chickens in a challenge to examine the protective efficacy of the rFPV. When the chickens were challenged with IBV Ch3 or Ch5, the control birds had respiratory signs of infections bronchitis, whereas all the vaccinated birds were clinically normal although low levels of the IBV infection were detected by a differential ELISA. In contrast, in the chickens challenged with IBV H4, all control birds and vaccinated birds suffered from the highly lethal IBV H4 infection. Our results suggest that the C-terminal 119 amino acid of the nucleocapsid expressed by FPV is a host-protective antigen and may induce cross-protective immunity against illness among some IBV strains.

Plasminogen activator inhibitor-1 gene polymorphism 4G/4G genotype and lupus nephritis in Chinese patients

BACKGROUND

Abnormal regulation in the coagulation and fibrinolytic system may play an important role in mediating glomerular damage in lupus nephritis. Indeed, glomerular thrombosis occurs frequently in lupus nephritis and predicts the future development of glomerular sclerosis. In the murine model of active lupus nephritis, plasminogen activator inhibitor-1 (PAI-1) gene was overexpressed throughout the kidney, both within the glomeruli and also in tubules and vessels. The level of PAI-1 expression in the tissues appeared to correlate with the progression of lupus nephritis. Recently, a single base pair insertion/deletion 4G/5G polymorphism of the PAI-1 gene has been identified and shown to alter plasma PAI-1 activity. This study was therefore conducted to determine the association of the 4G/5G polymorphism of the PAI-1 gene with the development and severity of lupus nephritis.

METHODS

The PAI-1 gene polymorphism of 118 systemic lupus erythematosus (SLE) patients and 103 healthy controls who were gender and age matched was determined using standard polymerase chain reaction. PAI-1 genotype results were studied in relationship to the development and severity of lupus nephritis.

RESULTS

Allele frequencies of 4G/5G allele were 0.59/0.41 in lupus patients and 0.59/0.41 in controls (P = 1.000). No significant difference was noted in the genotype distribution between SLE patients with and without nephritis. However, lupus nephritis patients with the 4G4G genotype showed significantly heavier proteinuria (5.0 vs. 3.7 g/day; P = 0.023) when compared with patients with 4G5G and 5G5G genotypes. Also, 73.3% patients with 4G4G had an activity index > or =8 versus 37.3% patients with 4G5G and 5G5G (P = 0.003). Extensive necrotizing lesions were seen in 51.7% patients with 4G4G as compared with 23.5% patients with 4G5G and 5G5G (P = 0.014). The association of the 4G4G gene polymorphism with a higher nephritis activity and more severe necrotizing lesions persisted when only class III and class IV nephritis patients were studied. On the other hand, no significant association was noted between the PAI-1 gene polymorphism and the chronicity of the nephritis.

CONCLUSION

These findings suggest that the 4G/5G polymorphism of the PAI-1 gene is associated with the activity but not the chronicity of lupus nephritis. The presence of the 4G4G genotype does not increase the risk of developing SLE or lupus nephritis, but predicts the development of higher nephritis activity and more extensive necrotizing lesions.

Human glial cell line-derived neurotrophic factor receptor alpha 4 is the receptor for persephin and is predominantly expressed in normal and malignant thyroid medullary cells

Glial cell line-derived neurotrophic factor (GDNF) family ligands signal through receptor complex consisting of a glycosylphosphatidylinositol-linked GDNF family receptor (GFR) alpha subunit and the transmembrane receptor tyrosine kinase RET. The inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN2), associated with different mutations in RET, is characterized by medullary thyroid carcinoma. GDNF signals via GFRalpha1, neurturin via GFRalpha2, artemin via GFRalpha3, whereas the mammalian GFRalpha receptor for persephin (PSPN) is unknown. Here we characterize the human GFRalpha4 as the ligand-binding subunit required together with RET for PSPN signaling. Human and mouse GFRalpha4 lack the first Cys-rich domain characteristic of other GFRalpha receptors. Unlabeled PSPN displaces (125)I-PSPN from GFRA4-transfected cells, which express endogenous Ret. PSPN can be specifically cross-linked to mammalian GFRalpha4 and Ret, and is able to promote autophosphorylation of Ret in GFRA4-transfected cells. PSPN, but not other GDNF family ligands, promotes the survival of cultured sympathetic neurons microinjected with GFRA4. We identified different splice forms of human GFRA4 mRNA encoding for two glycosylphosphatidylinositol-linked and one putative soluble isoform that were predominantly expressed in the thyroid gland. Overlapping expression of RET and GFRA4 but not other GFRA mRNAs in normal and malignant thyroid medullary cells suggests that GFRalpha4 may restrict the MEN2 syndrome to these cells.

Estrogen and progesterone distinctively modulate methamphetamine-induced dopamine and serotonin depletions in C57BL/6J mice

Intra-striatal infusion of a high dose (100 microg/3 microl) of methamphetamine produced long-lasting depletions of striatal dopamine and serotonin in both male and female mice. Male mice exhibited a greater depletion of striatal dopamine and serotonin than female mice. A similar trend of sexual differences was observed when 4 cumulative doses of methamphetamine were administered systemically. Thus, the sexual differences in methamphetamine-induced neurotoxicity in the striatum are probably not due to their differences in peripheral metabolism of methamphetamine. Moreover, ovariectomized (OVX) mice supplemented with 3 daily doses of estradiol benzoate (EB) at high or physiological levels, 3 daily doses of progesterone (P), and 2 doses of EB followed by 1 dose of P all demonstrated higher striatal dopamine levels following methamphetamine treatment as compared to vehicle-supplemented controls. The OVX mice pretreated with 3 daily doses of P exhibited the highest striatal serotonin levels after methamphetamine administration of all groups. In conclusion, sexual differences observed in methamphetamine-induced striatal neurotoxicity may be modulated by ovarian hormones.

Reconstitution of mitochondrial processing peptidase from the core proteins (subunits I and II) of bovine heart mitochondrial cytochrome bc(1) complex

Mature core I and core II proteins of the bovine heart mitochondrial cytochrome bc(1) complex were individually overexpressed in Escherichia coli as soluble proteins using the expression vector pET-I and pET-II, respectively. Purified recombinant core I and core II alone show no mitochondrial processing peptidase (MPP) activity. When these two proteins are mixed together, MPP activity is observed. Maximum activity is obtained when the molar ratio of these two core proteins reaches 1. This indicates that only the two core subunits of thebc(1) complex are needed for MPP activity. The properties of reconstituted MPP are similar to those of Triton X-100-activated MPP in the bovine bc(1) complex. When Rieske iron-sulfur protein precursor is used as substrate for reconstituted MPP, the processing activity stops when the amount of product formation (subunit IX) equals the amount of reconstituted MPP used in the system. Addition of Triton X-100 to the product-inhibited reaction mixture restores MPP activity, indicating that Triton X-100 dissociates bound subunit IX from the active site of reconstituted MPP. The aromatic group, rather than the hydroxyl group, at Tyr(57) of core I is essential for reconstitutive activity.

Augmentation of myocardial transfection using TerplexDNA: a novel gene delivery system

Gene therapy is a potential new strategy for the treatment of cardiovascular disease. The most efficacious method of gene delivery remains a key hurdle to effective gene therapy. We present the application of a novel, nonviral gene delivery system (TerplexDNA) to augment myocardial transfection. The hearts of New Zealand white rabbits were injected with reporter genes, luciferase cDNA or beta-galactosidase cDNA, either as naked plasmid DNA or plasmid DNA complexed with stearyl-poly(L-lysine)-low density lipoprotein (TerplexDNA). Three day left heart myocardial cell lysates produced 44571 +/- 8730 RLU (RLU = total light units/mg protein) for the TerplexDNA luciferase rabbits versus 1638 +/- 567 RLU for the naked luciferase rabbits (P = 0.002). Thirty days after injection, myocardial lysates produced 677 +/- 52 RLU for the TerplexDNA luciferase hearts versus 18 +/- 3 RLU for the naked luciferase hearts (P = 0.002). Histologic analysis of the hearts transfected with beta-galactosidase showed that TerplexDNA increased the area and depth of transfection compared with the naked plasmid DNA alone. The hearts of Sprague-Dawley rats were injected in a similar fashion and analyzed at 1, 3, 5, 10, 15, 25 and 30 days after injection. The naked luciferase injected hearts showed transient elevation of luciferase activity to day 5 but fell back to baseline levels after that time-point. The TerplexDNA luciferase injected hearts had significantly elevated luciferase activity to 30 days. The Terplex gene delivery system significantly augments myocardial transfection compared with a naked plasmid DNA system alone. The advantage in transfection efficiency appears to be related to the unique properties of the TerplexDNA carrier molecule. The TerplexDNA delivery system represents a novel means to augment transfection of the myocardium.