Differential regulation of placental and germ cell alkaline phosphatases by glucocorticoid and sodium butyrate in human gastric carcinoma cell line TMK-1

The expression and regulation of alkaline phosphatase (AP) was studied in the human gastric cancer cell line TMK-1. Biochemical analysis, reverse transcription-polymerase chain reaction, and Northern blot analysis demonstrated that the cells express placental, germ cell, and intestinal AP isozymes constitutively. Dexamethasone (Dex), a synthetic glucocorticoid, was shown to specifically induce the placental AP activity to about 10-fold and sodium butyrate (NaBu) induced germ cell AP activity to about 4-fold, respectively. In contrast, these two agents showed little effect on the level of intestinal isozymes. Dex and NaBu also differentially induced the mRNA levels of the placental and germ cell APs. Northern blot analysis of the placental AP transcript in the presence of the transcription inhibitor, 5, 6-dichloro-1-beta-D-ribofuranosyl benzimidazole, revealed that the half-life of placental AP mRNA is about 27 h for both the Dex-treated and untreated cells. Nuclear run-on transcription analysis indicated an apparent increase in the rate of placental AP gene transcription in Dex-treated cells. These results indicated that the effect of Dex occurred primarily by activation of the placental AP gene transcription in the cells. In order to study the direct Dex and NaBu effect on AP gene expression, the proximal promoter regions of AP genes were fused to luciferase reporter vectors. Despite the high similarity in nucleotide sequences of these two genes, transient transfection analysis demonstrated that Dex and NaBu exerted a specific stimulation only through the respective placental and germ cell AP gene promoter. Taken together, this study indicates that the expression of PAP and GCAP isozymes have specific regulatory mechanisms that can be differentially controlled by signals including glucocorticoid and NaBu.

Altered expression of nuclear matrix proteins in etoposide induced apoptosis in HL-60 cells

The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.

Esophageal cancer after endoscopic injection sclerotherapy for esophageal varices

We reported two cases of squamous cell carcinoma of the esophagus following endoscopic injection sclerotherapy (EIS) for esophageal varices. Both patients were cigarette smokers and had a long history of alcohol abuse. HBsAg and Anti-HCV were negative, and Anti-HBs was positive in one of the patients. They were diagnosed as alcoholic cirrhosis with esophageal varices and received EIS treatment. Sotradecol was utilized as the sclerosant with a mean total volume of around 30 ml. Patients developed dysphagia at 5 and 48 months following EIS, respectively. Endoscopic examination showed stenosis and ulcerative mass at the lower portion of the esophagus. Biopsy revealed well- to moderately differentiated squamous cell carcinoma of the esophagus. We conclude that endoscopic follow-up is essential and carcinoma of the esophagus should be included in the differential diagnosis for esophageal ulceration and dysphagia following EIS, particularly in those patients with risk factors for developing esophageal carcinoma.

Further characterization of Escherichia coli brain microvascular endothelial cell invasion gene ibeA by deletion, complementation, and protein expression

The ibeA gene (ibe10) previously identified by TnphoA mutagenesis is part of a 50-kDa full-length open-reading frame (ORF) encoded by a 1.37-kb DNA fragment. An isogenic in-frame deletion mutant of ibeA (ZD1) was constructed by chromosomal gene replacement with a suicide plasmid pCVD442 carrying a 2.1-kb DNA fragment with an ibeA deletion. Similar to the previously described TnphoA insertion mutant of ibeA, the isogenic ibeA deletion mutant ZD1 was significantly less invasive in human brain microvascular endothelial cells (BMECs) than the parent strain. The mutant ZD1 was fully complemented by the ibeA ORF. The ibeA gene was subcloned into pET28a(+) and was expressed as a recombinant protein with an N-terminal histidine tag. The recombinant IbeA protein had much greater activity (50 times) in blocking the invasion of BMECs by Escherichia coli K1 than did the partial protein fragment, which provides further evidence that ibeA is an important determinant for E. coli K1 invasion of BMECs.

HIV epitope-peptides in aluminum adjuvant induced high levels of epitope-specific antibodies

Some neutralizing epitopes on HIV-1 envelope proteins were shown to induce antibodies that could effectively inhibit the infection of different HIV-1 strains in vitro. But only very low levels of antibodies to these epitopes were determined in the HIV-1 infected individuals. In this study, the aluminum (alum) adjuvant to increase the immunogenicity of the neutralizing epitopes was used. Three epitope-peptides [C-(ELDKWAG)4, C-(RILAVERYLKD-G)2 and C-(GPGRAFY)2], which contain three epitopes (ELDKWA, RILAVERYLKD, GPGRAFY) from the HIV-1 Env proteins, were synthesized and conjugated to carrier protein keyhole limpet hemocyanin (KLH). The epitope-vaccines C-(ELDKWAG)4-KLH and C-(RILAVERYLKD-G)2-KLH in alum induced high levels of epitope-specific antibodies recognizing the epitopes from epitope-peptides C-(ELDKWAG)4 and C-(RILAVERYLKD-G)2, as well as the gp41 C-domain peptides P2 [C-TSLIHSLIEESQNQQEKNEQELLELDKWA (aa 646-674)] and P1 [LQARILAVERYLKDQQL (aa 583-599)] and the recombinant soluble gp41 (rsgp41) bearing both epitopes (antibody titer in rabbit sera was 1:12800-25,600 dilution). Immunoblotting analysis demonstrated that the antibodies in both antisera bound to rsgp41, indicating that both antibodies recognized the natural epitopes on rsgp41 protein. The epitope-vaccines C-(GPGRAFY)2-KLH induced moderate GPGRAFY epitope-specific antibody response with a titer of 1:6,400. In contrast, as it was demonstrated in previous studies, the immunization with rgp160 induced weak antibody response to these three epitopes (titer of 1:400-1600). This suggests that epitope-peptides conjugated to KLH when infected with alum significantly increases immunogenicity of gp41 neutralizing epitopes providing a hope for the development of an HIV-1 vaccine.

Erythema induratum: a clinicopathologic and polymerase chain reaction study

BACKGROUND

In Taiwan, cutaneous lesions with granulomatous lobular panniculitis, with or without vasculitis, are usually diagnosed as erythema induratum (EI), a common form of tuberculid associated with tuberculosis. However, there has been no study to elucidate the extent of this association in Taiwan. The aim of this study was to document the spectrum of the pathologic findings in EI and its association with Mycobacterium tuberculosis.

METHODS

The diagnostic/inclusion criteria for EI were recurrent tender subcutaneous nodules on the legs, histopathologic findings of granulomatous lobular or septolobular panniculitis plus necrosis or vasculitis, and positive response to antituberculosis therapy. The clinicopathologic findings in the 12 cases that fulfilled these criteria were analyzed, and nested polymerase chain reaction (PCR) was used to identify M. tuberculosis complex DNA from formalin-fixed, paraffin-embedded sections.

RESULTS

Eleven women and one man were included in the study, ranging from 18 to 70 years old (mean, 40.6 yr). The duration of the disease ranged from 10 days to 10 years (mean, 2.1 yr). Histopathology revealed granulomatous panniculitis; a diffuse lobular pattern was observed in nine cases and a focal lobular/septolobular pattern in three. Vasculitis was found in nine cases, four affecting an artery or vein, with three occurring in the patients with focal panniculitis. Ten cases showed various degrees of caseous necrosis. Eosinophils or focal eosinophilia were fairly common (10 patients). From PCR, nine patients were positive for M. tuberculosis complex DNA.

CONCLUSIONS

Type III and IV hypersensitivity reactions to M. tuberculosis complex were involved in the pathogenesis of EI. Our results suggest that approximately half of the cases with pathologic findings consistent with EI or nodular vasculitis in Taiwan are associated with M. tuberculosis.

[Meiosis-like reduction in the culture system for somatic embryogenesis of Arabidopsis thaliana]

The somatic meiosis-like reduction was observed in some cells in the embryogenic calli of Arabidopsis thaliana. One type was somatic chromosome reductional grouping, in which the chromosomes in a cell either separated into two groups, or separated into more than two groups at prophase or metaphase. The chromosomes separated directly, the morphology of the chromosomes did not show any role of the spindle fibers. Chromosome reductional grouping happened more frequently in polyploid cells. The other type was somatic meiossi which was analogous to that existed in the process of gametogenesis, and characterized by the pairing and synapsis of homologues chromosomes. In the embryogenic calli cultured on dedifferentiation medium, about 3% of the observed cells contained haploid number of chromosomes, while the tetrad cells occurred at a frequency of about 4%. The somatic meiosis-like reduction could result in the recombination of chromosomes in the cells generated by these processes. The roles of somatic meiosis-like reduction in the somatic embryogenesis and somaclonal variations were discussed.

A novel heat-labile phospholipid-binding protein, SVS VII, in mouse seminal vesicle as a sperm motility enhancer

SVS VII, one of seven major proteins in mouse seminal vesicle secretion, was purified to homogeneity. Neither glycoconjugate nor free thiol group was detected in the protein. The primary structure deduced from the corresponding cDNA was confirmed using amino acid sequence determination, which supported the finding that SVS VII consists of 76 amino acid residues with five disulfide bridges. Accordingly, it has a theoretical molecular mass of 8538, which was proven using the mass spectrum of SVS VII. The CD spectrum of SVS VII in 50 mm phosphate buffer at pH 7.4 appeared as one negative band arising from the beta form at 217 nm and several fine structures due to nonpeptide chromophores including a prominent band for the disulfide bond at 250 nm. This, together with the predicted secondary structures, indicated no helices but a mixture of beta form, beta turn, and unordered form in SVS VII. A cytochemical study illustrated the presence of the SVS VII-binding region on the entire surface of mouse sperm. The SVS VII-sperm binding was inhibited by the dispersed sperm lipids. The results of TLC overlay assay for the binding of (125)I-SVS VII to phospholipids and the interaction between SVS VII and phospholipid liposomes demonstrated a specific binding of this protein to both phosphatidylethanolamine and phosphatidylserine. The SVS VII-sperm binding greatly enhanced sperm motility but did not induce sperm capacitation. Heating the protein solution for 10 min at 90 degrees C unfolded the protein molecule, and the unfolded SVS VII immobilized the sperm.

Amphetamine elicited potential changes in vertebrate and invertebrate central neurons

The effects of amphetamine on potential changes in both vertebrate and invertebrate central neurons and factors affecting the potential changes were tested. The animals studied included mice, newborn rat and African snail. Seizure was elicited after lethal doses of d-amphetamine (75 mg/kg, i.p.) administration in mice. Repetitive firing of the action potentials were elicited after d-amphetamine (1-30 microM) administration in thin thalamic brain slices of newborn rat. Bursting firing of action potentials in the giant African central RP4 neuron were also elicited after d-amphetamine or l-amphetamine (0.27 mM) administration. The amphetamine elicited bursting firing of action potentials was not blocked even after high concentrations of d-tubocurarine, atropine, haloperidol, hexamethonium administration. Therefore, the amphetamine elicited potential changes may not be directly related to the activation of the receptors of the neuron. The bursting firing of action potentials elicited by amphetamine occurred 20-30 min after amphetamine administration extracellularly, even after high concentrations of d-amphetamine administration (0.27, 1 mM). However, the bursting firing of potentials occurred immediately if amphetamine was administrated intracellularly at lower concentration. Extracellular application of ruthenium red, the calcium antagonist, abolished the amphetamine elicited bursting firing of action potentials. If intracellular injection of EGTA, a calcium ion chelator, or injection with high concentrations of magnesium, the bursting firing of potentials were immediately abolished. These results suggested that the active site of amphetamine may be inside of the neuron and the calcium ion in the neuron played an important role on the bursting of potentials. In two-electrode voltage clamped RP4 neuron, amphetamine, at 0.27 mM, decreased the total inward and steady outward currents of the RP4 neuron. d-Amphetamine also decreased the calcium, Ia and the steady-state outward currents of the RP4 neuron. Besides, amphetamine elicited a negative slope resistance (NSR) if membrane potential was in the range of -50 to -10 mV. The NSR was decreased in cobalt substituted calcium free and sodium free solution. The effects of secondary messengers on the amphetamine elicited potential changes were tested. The bursting firing of action potentials elicited by amphetamine in central snail neurons decreased following extracellular application of H8 (N-(2-methyl-amino) ethyl-3-isoquinoline sulphonamide dihydrochloride), a specific protein kinase A inhibitor and anisomycin, a protein synthesis inhibitor. However, the bursting firing of action potentials were not affected after extracellular application of H7 (1,(5-isoquinolinesulphonyl)-2-methylpiperasine dihydrochloride), a specific protein kinase C (PKC) inhibitor, or intracellular application of GDPbetaS, a G protein inhibitor. The oscillation of membrane potential of the bursting activity was blocked after intracellular injection of 3'-deoxyadenosine, an adenylyl-cyclase inhibitor. These results suggested that the bursting firing of action potentials elicited by d-amphetamine in snail neuron may be associated with the cyclic AMP second messenger system; on the other hand, it may not be associated with the G protein and protein kinase C activity. It is concluded that amphetamine elicited potential changes in both vertebrate and invertebrate central neurons. The changes are closely related to the ionic currents and second messengers of the neurons.

Differential Expression and Geographic Variation of the Venom Phospholipases A2 of Calloselasma rhodostoma and Trimeresurus mucrosquamatus

To investigate the geographic variations in venoms of two medically important pitvipers, we have purified and characterized the phospholipases A2 (PLA2s) from the pooled venoms of Calloselasma rhodostoma from Malaysia, Thailand, Indonesia, and Vietnam, as well as the individual venom of Trimeresurus mucrosquamatus collected from both North and South Taiwan. Enzymatic and pharmacological activities of the purified PLA2s were also investigated. The complete amino acid sequences of the purified PLA2s were determined by sequencing the corresponding cDNAs from the venom gland and shown to be consistent with their molecular weight data and the N-terminal sequences. All the geographic venom samples of C. rhodostoma contain a major noncatalytic basic PLA2-homolog and two or three acidic PLA2s in different proportions. These acidic PLA2s contain Glu6-substitutions and show distinct inhibiting specificities toward the platelets from human and rabbit. We also found that the T. mucrosquamatus venoms from North Taiwan but not those from South Taiwan contain an Arg6-PLA2 designated as TmPL-III. Its amino acid sequence is reported for the first time. This enzyme is structurally almost identical to the low- or nonexpressed Arg6-PLA2 from C. rhodostoma venom gland, and thus appears to be a regressing venom component in both of the Asian pitvipers.

Development of a capillary electrophoresis-77 K luminescence detection system for online spectral identification

We have demonstrated that capillary electrophoresis (CE) can be easily interfaced with 77 K luminescence spectroscopy (LS) for separation and online spectral identification of structurally similar analytes. This novel CE-LS apparatus consists of a regular CE system, instrumentation for LS and a specially designed capillary Dewar. When the separating molecules traverse into the cryostat detection window, liquid nitrogen is added, freezing the separating analyte zones within the capillary. At low temperature, detection limits are improved via signal averaging and the inherent increase in quantum yield at 77 K. We present the first application of the CE-LS system to structural isomers (2,3- and 3,4-methylenedioxymethamphetamine) and stereoisomers (trans- and cis-resveratrol). With this approach, the CE-LS interfacing provides a sensitive, accurate, rapid, simple and economic methodology for analytical chemistry.

HIV-1 gp41 and type I interferon: sequence homology and biological as well as clinical implications

HIV-1 gp41-like human type I interferon (IFN) could inhibit lymphocyte proliferation and up-modulate MHC class I and II and ICAM-1 molecule expression. Sequence comparison indicates that a similar epitope RILAV-YLKD exists between N-domain of gp41 and two regions in IFN-alpha(aa29-35 and 113-129), IFN-beta (aa31-37 and 125-138) and IFN-omega (aa29-35 and 123-136), which was shown to form IFN-alpha/beta-receptor binding site. Weak sequence similarity was also found to exist in both regions on gp41 and type I IFN of murine and bovine. Experimental studies indicated that a common immunological epitope exists between gp41 and IFN-alpha and -beta. Antibodies against human IFN-alpha and -beta recognized the common immunological epitope and inhibited gp41-binding to the potential cellular receptor protein p45. Moreover, the polyclonal antibody to IFN-beta completely inhibited gp41-binding to human T, B cells and monocytic cells, while IFN-alpha could only inhibit this binding incompletely. It was interestingly observed that human IFN-beta after preincubating with cells could incompletely inhibit the binding of gp41 to human B cells and monocytic cells, and very weakly inhibit the binding to human T cells, indicating that the receptor for IFN-beta-binding may be involved in gp41 binding. This potential relationship may be based on the amino acid sequence homology in the receptor binding region between gp41 and IFN-beta. It was observed that the increased levels of antibodies against human IFN-alpha and -beta exist in HIV-1-infected individuals and are associated with the common epitope on gp41. Besides, several studies provided experimental evidence that the common immunological epitope could induce protective activity against HIV-1. The IFN-alpha-based vaccine has showed a significant reduction of disease progression in IFN-alpha-vaccine-treated HIV-infected patients. Recent experimental evidence indicates that gp41 and IFN-beta were involved in downregulation of CCR5 expression and induction of cell activation or signal transduction. Whether it may be performed by a similar mechanism is still to be investigated.

Effects of flowable composite lining and operator experience on microleakage and internal voids in class II composite restorations

STATEMENT OF PROBLEM

When inexperienced clinicians perform class II composite restorations, improper placement techniques can lead to problems, including marginal adaptation and void formation.

PURPOSE

The aim of this study was to determine the influence of flowable composite linings on marginal microleakage and internal voids in class II composite restorations performed by practitioners with different levels of experience.

MATERIAL AND METHODS

Eighty extracted molars were prepared with mesial and distal class II cavity preparations and divided into 4 groups. Each group was restored separately with the following materials: Prodigy/Revolution lining (group I), Prodigy (group II), Tetric Ceram/Tetric Flow lining (group III), and Tetric Ceram (group IV). Each group was equally divided and restored by 2 practitioners, one experienced and another untrained in composite restorations. After restoration, all teeth were stored for 24 hours, thermocycled (at 5 degrees C to 60 degrees C) 1500 times, and soaked in 2% basic Fuchsin dye for 24 hours. After soaking, the teeth were sectioned, and gingival marginal microleakage and internal voids (at the gingival wall interface and in the cervical and the occlusal parts) were recorded. Data were analyzed with the Kruskal-Wallis test.

RESULTS

There was no significant reduction in microleakage for either practitioner. There were fewer interface voids within pairs with or without flowable composite linings made by the experienced practitioner (P<.05).

CONCLUSION

When flowable composite lining was placed at the gingival floor of a class II composite restoration by an experienced practitioner, voids in the restored interface were reduced. Gingival marginal sealing was not improved by the same technique.

Depigmented genital extramammary Paget's disease: a possible histogenetic link to Toker's clear cells and clear cell papulosis

BACKGROUND

The histogenesis of extramammary Paget's disease (EMPD) is still controversial. Benign pagetoid cells of the nipple first described by Toker and the similar clear cells found in white maculopapules of clear cell papulosis (CCP) have been proposed to be potential precursor cells giving rise to EMPD and primary intraepidermal Paget's disease in the nipple. The observation of a rare case of depigmented EMPD provided us with a chance to examine further the interesting Toker's clear cell/CCP hypothesis.

METHODS

We performed pathologic studies, including Fontana-Masson stain and immunostaining for AE1/AE3 and S100P, on a new case of depigmented EMPD manifesting a 4 x 3 cm hypopigmented-depigmented patch on the root of the penis.

RESULTS

The lesion showed extensive intraepithelial proliferation of atypical pagetoid cells with markedly reduced epidermal melaninization but nearly normal numbers of melanocytes. The tumor cells were strongly positive for AE1/AE3 by immunostaining. Some tumor cells displayed tadpole-like morphology resembling the pagetoid cells of CCP. Such morphology was not observed in two random examples of non-depigmented genital EMPD.

CONCLUSIONS

The findings of tadpole-shaped pagetoid cells and depigmentation in the present case suggest that depigmented EMPD may be histogenetically related to CCP. Depigmented EMPD should be considered in the differential diagnosis of vitiligo, depigmented mycosis fungoides and lichen sclerosus located along the milk line.

N- and C-domains of HIV-1 gp41: mutation, structure and functions

Recent studies demonstrated that the N- and C-domains of HIV-1 gp41 is involved in virus-mediated membrane fusion resulting in HIV-entry into the target cells. Up to now, viral mutation baffled many scientists to develop effective vaccines and drugs against HIV-1. To acquire more information of mutation of gp41 and to reveal the relationship of structure and function of the N- and C-domains, we compared and analyzed amino acid sequences of the gp41 ectodomain (aa 512-681) of 862 isolates from most HIV-1 clades (including A, B, C, D, E, F, G, H, I, J and O clades). A consensus sequence of the ectodomain with the highest frequency emerging on each position is constituted. The fusion domain and the N-domain belong to the most conserved regions in gp41, and most variable residues assemble partial to the C terminal of gp41. The hydrophobicity of each position is also calculated. The a and d positions in the N-domain for maintaining stabilization of the trimeric coiled coil interactions are highly conservative, and the e and g positions in the C-domain to retain the interaction show also highly conservative. The strange high conservation of the c residues may have an implication in the coiled coil structure. The highly conserved residues form the lining of the hydrophobic cavity and the deep cavity is an ideal target for small molecular inhibitors. On the C-terminal of the C-domain there is a highly conserved segment GIVQQQ. They are intimately involved in forming the three interfaces between neighboring helices. The function of the N- and C-domains, such as binding to the potential cellular receptor and inducing protective activities, are also discussed. These studies on the mutation, structure and functions of the N- and C-domains suggested that both domains become a new focus to develop effective vaccine and antiviral drugs in the new strategies.

Compact, 220-ps visible laser employing single-pass, cascaded frequency conversion in monolithic periodically poled lithium niobate

We report the first demonstration to our knowledge of 220-ps visible laser generation from passively Q-switched-laser pumped periodically poled lithium niobate (PPLN) in a single-pass, cascaded frequency-conversion process. The monolithic PPLN consists of a 1-cm section for frequency doubling the 1064-nm Nd:YAG pump laser to a 532-nm laser and a subsequent 4-cm section for generating the visible laser in a 532-nm-pumped optical parametric generation (OPG) process. In generating the 622.3-nm OPG signal wavelength we measured a 3.0-microJ/pulse pump threshold at the 1064-nm wavelength, 16% overall efficiency, and 35% slope efficiency at two times threshold. At 10(-6) pump duty cycle and 20-mW average power in the visible, photorefractive damage was not observed at the phase-matching temperature of 40.3 degrees C.

[Clinical and experimental study on treatment of childhood hyperkinetic syndrome with yizhidan]

OBJECTIVE

To observe the clinical effect of Yizhidan (YZD) in treating childhood hyperkinetic syndrome (CHS) and its mechanism.

METHODS

Random single blind method was used in clinical study to observe the clinical effect of YZD and compared with that of Ritalin. The dysmnesia model animal was used to observe the effect of YZD on learning memory function and cerebral monoamine neurotransmitter content.

RESULTS

The markedly effective rate and the total effective rate of YZD were 45.56% and 87.78%, which were similar to those of Ritalin (53.33% and 86.67%). The Conners index lowered in both groups, showing insignificant difference (P > 0.05). Experimental observation showed that YZD could significantly improve the soft neurologic signs and abnormal encephalogram with less side-effects in comparing with Ritalin (P < 0.05). Moreover, YZD could obviously improve the learning memory disturbance induced by scopolamine, sodium nitrite and ethanol, and significantly increased the contents of DA in cerebral tissue, as compared with that of the control group, the difference was significant (P < 0.01). It also showed effect on DOPAC, NE, HVA, 5-HT and 5-HIAA of mice in certain degree.

CONCLUSION

YZD is an effective drug in treating CHS, its mechanism might be probably related to the improvement of the memory and the enhancement of DA receptor in cerebral tissue.

ELNKWA-epitope specific antibodies induced by epitope-vaccine recognize ELDKWA- and other two neutralizing-resistant mutated epitopes on HIV-1 gp41

Based on the fact that monoclonal antibody (mAb) 2F5 recognizing ELDKWA-epitope on HIV-1 gp41 separately or in combination with other mAbs showed potent neutralizing activity to a wide range of primary HIV-1 isolates in vivo and in vitro, but this epitope undergoes restricted mutation. ELNKWA is a neutralizing-resistant mutated epitope. We induced ELNKWA-epitope-specific polyclonal and monoclonal antibodies and studied the interaction of the antibodies with ELDKWA-epitope and other two neutralizing-resistant mutated epitopes. The candidate ELNKWA-epitope-vaccine induced a high level of antibodies to the ELNKWA-epitope-peptide. The ELNKWA-epitope-specific polyclonal antibodies bound not only the ELNKWA-, but also ELDKWA-, ELEKWA- and ELDEWA-epitope-peptides in ELISA-assay. Moreover, the antibodies also recognized four C-domain-peptides (P5, P6, P7, P8) which contain these four epitopes, respectively. Interestingly, an ELNKWA-epitope-specific monoclonal antibody (TH-Ab1) induced by the candidate ELNKWA-epitope-vaccine could also recognize the four C-domain-peptides containing ELNKWA-, ELDKWA-, ELEKWA- and ELDEWK-epitopes. These results indicate that the candidate ELNKWA-epitope-vaccine could induce high levels of antibodies, which recognize the neutralizing epitope ELDKWA and three neutralizing-resistant mutated epitopes, suggesting that the candidate ELNKWA-epitope-vaccine may help to overcome the problem of viral escape from neutralization through mutation at D or K position, and may be developed as an effective vaccine with a broad neutralizing activity against HIV-1.

Lack of evidence to support the association of the human prion gene with schizophrenia

Recently a new variant of Creutzfeldt-Jakob disease, a human prion disease, with prominent psychiatric manifestations in the early stage was identified, suggesting that human prion disease may be associated with mental disorders. Furthermore, a novel missense mutation with asparagine-to-serine substitution at codon 171 of the human prion gene (N171S) was identified in a family with severe psychiatric symptoms. This finding provides further clue that the prion gene may be a susceptibility gene for certain psychiatric disorders. We systematically sequenced the protein-coding and untranslated exons of prion gene in 62 Han Chinese schizophrenic patients with positive family history from Taiwan. We identified two polymorphisms that alter amino acid sequences, a methionine/valine at codon 129 (M129V) and a glutamate/lysine at codon 219 (E219K), respectively. Further comparison of the genotype, allele and haplotype frequency distributions of these two polymorphisms between 234 schizophrenic patients and 100 non-psychotic controls, however, did not reveal significant differences between two groups. Besides, no other mutations in the prion gene were identified in these 62 patients. Hence, our results suggest that the prion gene may not play a major role in conferring susceptibility to schizophrenia.

Molecular structure, dynamic expression, and promoter analysis of zebrafish (Danio rerio) myf-5 gene

We isolated a 1,438 bp cDNA fragment that encoded Myf-5 myogenic factor of zebrafish. The deduced amino acid contained 237 residues, including the basic helix-loop-helix domain that is conserved in all known Myf-5. The zebrafish myf-5 transcripts were first detectable at 7.5 hpf, increased substantially until 16 hpf, and then declined gradually to an undetectable level by 26 hpf. During somitogenesis, zebrafish myf-5 transcripts were distributed mainly in the somites and segmental plates. Prominent signals occurred transiently in adaxial cells in two parallel rows but did not extend beyond the positive-signal somites. Various lengths of upstream region of zebrafish myf-5 fused with EGFP gene were used to carry out transgenic analysis. Results showed that a small, 82 bp (nucleotide positions from -82 to -1), regulatory cassette is sufficient to control the somite- and stage-specific expression of zebrafish myf-5 during early development.

Cloning, distribution and functional analysis of the type III sodium channel from human brain

The type III voltage-gated sodium channel was cloned from human brain. The full-length cDNA has 89% identity with rat type III, and the predicted protein (1951 amino acids) has 55 differences. The expression pattern of human type III mRNA was determined in adult brain tissue and, in contrast to rat, was detected in many regions, including caudate nucleus, cerebellum, hippocampus and frontal lobe. The human type III channel was stably expressed in Chinese hamster ovary (CHO) cells and its biophysical properties compared to the human type II channel using identical conditions. The voltage dependence and kinetics of activation were found to be similar to that of type II. The kinetics of inactivation of the two human subtypes were also similar. However, type III channels inactivated at more hyperpolarized potentials and were slower to recover from inactivation than type II. When expressed in human embryonic kidney (HEK293T) cells, type III channels produced currents with a prominent persistent component, which were similar to those reported for rat type II [Ma et al. (1997) Neuron, 19, 443-452]. However, unlike type II, this was prominent even in the absence of coexpressed G-proteins, suggesting type III may adopt this gating mode more readily. The distinct properties of the channel, together with its wide distribution in adult brain, suggest that in humans, type III may have important physiological roles under normal, and perhaps also pathological conditions.

A seminal vesicle autoantigen of mouse is able to suppress sperm capacitation-related events stimulated by serum albumin

We studied the effect of a mouse seminal vesicle autoantigen (SVA) on BSA-stimulated functions of mouse sperm. Uncapacitated, capacitated, and acrosome-reacted stages of sperm were morphologically scored, and the cellular zinc content was examined cytologically in a modified Tyrode solution at 37 degrees C for 80 min. More than 85% of control cells remained uncapacitated. Addition of 0.3% SVA to the cell incubation did not affect the cell status. Approximately 65% of cells were capacitated in the incubation medium containing 0.3% BSA. Only 30% of the cells became capacitated after incubation with 0.3% BSA and 0.3% SVA together. The decapacitation effect by 0.3% SVA could be subdued by more than 3% BSA in the cell incubation. Whereas BSA did, SVA did not cause removal of Zn(2+) from sperm, but SVA could suppress the BSA effect. The tyrosine phosphorylated proteins in sperm were detected after incubation in a modified HEPES medium containing 0.3% BSA and/or 0.3% SVA at 37 degrees C for 90 min. Whereas BSA enhanced greatly, SVA did not cause phosphorylation of proteins in the range of M:(r) 40 000-120 000. The BSA-stimulated protein tyrosine phosphorylation could be suppressed by SVA in the cell incubation.