[Application of VNTR D17S30 locus polymorphism in the paternity test]

A sensitive and rapid PCR-based technique was adopted to genotype the VNTR D17S30 locus. It was confirmed through the genetic analysis of 20 normal families that the inheritance of D17S30 locus coincides with Mendelian law as simple co-dominant. Retrospective analysis of 100 paternity cases demonstrated that D17S30 locus could be used in forensic paternity test in our country. The exclusion probability estimated from allele frequencies of D17S30 locus (74.04%) does not differ significantly from the observed rate of exclusion (80.00%) in these cases. In all excluded paternity cases there are two in which the exclusion evidence is solely provided by the D17S30 locus.

High affinity dimerization by Ski involves parallel pairing of a novel bipartite alpha-helical domain

c-Ski protein possesses a C-terminal dimerization domain that was deleted during the generation of v-ski, and has been implicated in the increased potency of c-ski in cellular transformation compared with the viral gene. The domain is predicted to consist of an extended alpha-helical segment made up of two motifs: a tandem repeat (TR) consisting of five imperfect repeats of 25 residues each and a leucine zipper (LZ) consisting of six heptad repeats. We have examined the structure and dimerization of TR or LZ individually or the entire TR-LZ domain. Using a quenched chemical cross-linking method, we show that the TR dimerizes with moderate efficiency (Kd = 4 x 10(-6) M), whereas LZ dimerizes poorly (Kd > 2 x 10(-5) M). However, the entire TR-LZ domain dimerizes efficiently (Kd = 2 x 10(-8) M), showing a cooperative effect of the two motifs. CD analyses indicate that all three proteins contain predominantly alpha-helices. Limited proteolysis of the TR-LZ dimer indicates that the two helical motifs are linked by a small loop. Interchain disulfide bond formation indicates that both the LZ and TR helices are oriented in parallel. We propose a model for the dimer interface in the TR region consisting of discontinuous clusters of hydrophobic residues forming "leucine buttons."

Effect of optic disc size or age on evaluation of optic disc variables

AIMS/BACKGROUND

It has been reported that the number of optic nerve fibres decrease with age, and the cup/disc (C/D) ratio increases as the optic disc size increases. Consequently, the normal value of the optic disc variables measured by an optic disc analyser may change according to the optic disc size or age. The effect of individual variations in optic disc size or age on interpretation of optic disc variables was investigated.

METHODS

Topographic optic disc variables of 104 normal Asian adults of both sexes aged 40 to 68 were measured using a confocal scanning laser ophthalmoscope (TopSS, Laser Diagnostic Technologies, Inc). Fourteen variables were evaluated according to the optic disc size or age. Statistical analysis was done by regression analysis.

RESULTS

With an increase in optic disc size, the increase in cup shape, effective area, 1/2 depth area, C/D ratio, neuroretinal rim area, volume above, volume below, and 1/2 depth volume were statistically significant (p < 0.05). However, contour variation, mean contour depth, average depth, maximum depth, average slope, and maximum slope were not affected (p > 0.1). Age did not have any significant influence on optic disc variables (p > 0.1).

CONCLUSION

Optic disc size, but not age, should be considered in the interpretation of optic disc variables.

Scavenger receptor BI promotes high density lipoprotein-mediated cellular cholesterol efflux

Scavenger receptor BI (SR-BI) binds high density lipoproteins (HDL) with high affinity and mediates the selective uptake of HDL cholesteryl ester. We examined the potential role of SR-BI in mediating cellular cholesterol efflux. In Chinese hamster ovary cells stably transfected with murine SR-BI, overexpression of SR-BI resulted in a 3-4-fold stimulation of initial cholesterol efflux rates. Efflux rates correlated with SR-BI expression in cells and HDL concentration in the medium. When incubated with synthetic cholesterol-free HDL, SR-BI-transfected cells showed approximately 3-fold increases in initial rates of efflux compared with control cells, indicating that SR-BI expression enhances net cholesterol efflux mediated by discoidal HDL. In six different cell types, including cultured macrophages, the rate of efflux of cholesterol mediated by HDL or serum was well correlated with cellular SR-BI expression level. In addition, in situ hybridization experiments revealed that SR-BI mRNA was expressed in the thickened intima of atheromatous aorta of apolipoprotein E knockout mice. Thus, SR-BI is an authentic HDL receptor mediating cellular cholesterol efflux. SR-BI may facilitate the initial steps of HDL-mediated cholesterol efflux in the arterial wall as well as later steps of reverse cholesterol transport involving uptake of HDL cholesterol in the liver.

[Effects of lanthanum and cerium on malignant proliferation and expression of tumor-related gene]

Cultured human gastric cancer cell line PAMC82 was studied in vitro to further verify anti-tumor effect sof rare-earth elements and explore their mechanism of tumor inhibition. Inhibitory effects of elements lanthanum and cerium on cell growth, reverse effects of them on reduction of malignancy and effects of them on level of expression of oncogene and cancer suppressor gene were observed. Lanthanum chloride, cerium chloride and mixed rare-earth chloride at levels of 0.5 to 1.5 mmol/L could inhibit obviously growth of cancer cells and change cell morphology and microtubule structure of PAMC82, similar to that of normal cells, their colony-forming ability lowered in soft agar, and expression of tumor suppressor gene p53, p16 and p21 increased and that of gene nm23 lowered.

[The prospective study of the influence of cytomegalovirus (CMV) infection of pregnant women to fetus]

Screening of CMV infection in 450 pregnant women in Shenyang was carried on by ELISA and PCR methods, and CMV infection was detected in 100 of their infants prospectively. The results were 97.11% of pregnant women with past infection, 0.89% with primary infection, 11.11% with recurrent infection, only 2% were susceptible. From 450 pregnant women, there were 3 infants with congenital defects and 3 abortions in active infective group, who were positive for IgM antibody, CMV DNA were positive in heparin peripheral blood, cervical secretion, placenta or amnionic fluid. The fetal infection rate and congenital defect rate in infective group were higher than that in inactive control group. Within 100 maternal-infant pair group, congenitally infected infants were 1.43 times higher in infective group than that in control group (RR = 1.43). Two infants with mental retardations (MDI<70) were born in infective group, but none in control group. In our study, primary infection of early pregnancy was most harmful to fetus, the intrauterine transmission rate was 33.3%. Among nine infected infants born from the infective group, two infants were with CID, and seven were symptomless. CMV screening is important for pregnant women in view of eugenic. When active CMV infection is found in early pregnancy, termination of pregnancy is better considered while CMV detection of amniotic fluid is also positive.

Intranasal immunization with C5a peptidase prevents nasopharyngeal colonization of mice by the group A Streptococcus

Early inflammatory events are initiated by phased production of C5a and interleukin-8 in tissue. Most serotypes of group A streptococci express a surface-bound peptidase (SCPA) which specifically cleaves mouse and human C5a chemotaxins. This study investigates the impact of SCPA on colonization of the nasopharyngeal mucosa of mice and evaluates its potential to induce protective immunity. Two strains, serotypes M6 and M49, which contain insertion and deletion mutations in the SCPA gene (scpA) and represent the two major subdivisions of group A streptococci, were characterized and compared in a mouse intranasal infection model. In this model, SCPA mutants were more rapidly cleared from the nasopharynges of inoculated mice compared with wild-type strains. A 2,908-bp fragment of scpA49 gene, obtained by PCR, was ligated to the expression vector pGEX-4T-1 and expressed in Escherichia coli. The affinity-purified deltaSCPA49 protein proved to be highly immunogenic in mice and rabbits. Although the purified deltaSCPA49 immunogen lacked enzymatic activity, it induced high titers of rabbit antibodies which were able to neutralize peptidase activity associated with M1, M6, M12, and M49 streptococci in vitro. This result confirmed that antipeptidase antibodies lack serotype specificity. Intranasal immunization of mice with the deleted form of the SCPA49 protein stimulated significant levels of specific salivary secretory immunoglobulin A (IgA) and serum IgG antibodies and reduced the potential of wild-type M1, M2, M6, M11, and M49 streptococci to colonize. These experiments suggest a new approach to vaccine development for prevention of streptococcal pharyngitis.

[Studies on peripheral blood stem cells mobilization by short course and high-dose G-CSF]

OBJECTIVE

To explore the effect of short-course, high dose granulocyte-colony stimulating factor (G-CSF) on peripheral blood stem cell (PBSC) mobolization.

METHODS

G-CSF 5microg/kg was injected subcutaneously twice daily for 3 consecutive days. On the first day and the fourth day the peripheral blood and bone marrow were collected for CFU-GM, BFU-E, CFU-mix assays and CD34/CD38 detection. A single apheresis of over 8000ml blood processing was performed with CS-3000 blood cell separator. The mononuclear cells were prepared for hematopoietic colony assays and CD34/CD38 detection before and after freezing.

RESULTS

After adminitration of G-CSF, the white blood cell count increased significantly. The CFU-GM, BFU-E, CFU-mix yields and CD34+ CD38+ cell and CD34+ CD38- cells also increased significantly (P<0.05). The median of mononuclear cells was 1.56 x 10(8)/kg. After one week freezing, the recovery of mononuclear cells, CFU-GM, BFU-E yields and CD34+ CD38+ cells were about 80% (P>0.05) and CFU-mix yields was 60%; The CD34+ CD38- cells were decreased compared with that of pre-freezing (P<0.05). The median of the reinfused mononuclear cells was 1.27 x 10(8)/kg,CFU-GM 6. 7 x 10(4)/kg, BFU-E 1.6 x 10(4)/kg, CFU-mix 0.32 x 10(4)/kg, CD34- CD38+ cells 1.6 x 10(6)/kg and CD34+ CD38- cells 0.23 x 10(6)/kg.

CONCLUSION

Short course and high-dose G-CSF can effectively mobilize the peripheral stem cells. The mononuclear cells, hematopoietic colonies and CD34/CD38 cells were satisfied for the peripheral stem cells rescue.

Photorefractive properties of iron-doped stoichiometric lithium niobate

The photorefractive properties of stoichiometric LiNbO(3) crystals with a small number of defect densities grown by the double-crucible Czochralski method are investigated and compared with the defect densities of commercially available congruent Fe-doped LiNbO(3) crystals. Two-wave-mixing experiments show that novel stoichiometric crystals exhibit larger photorefractive gain and considerably faster response times than congruent ones. The results indicate that the nonstoichiometry defect control of photorefractive crystals is of key importance for the improvement of their properties.

Familial occurrence of hemangioblastoma of central nervous system

OBJECTIVE

To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease.

METHODS

From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation.

RESULTS

Each patient had more than two relatives with hemangioblastoma. Multiple lesions were found in two of the six familial hemangioblastoma cases. All the patients recovered well after operation. So far, no victims have been discovered in the third generation.

CONCLUSIONS

The high occurrence rate of familial hemangioblastoma cases suggests an involvement of hereditary factors. We need a long follow-up study on the descendants of familial hemangioblastoma patients. MRI is of diagnostic value in determining the location and nature of hemangioblastoma in both brain and spinal cord. A thorough examination is necessary for hemangioblastoma patients, and microsurgery is important in removing the tumor.

Use of meiotic FISH for identification of a new monosome in Gossypium hirsutum L

The extensive use of molecular cytogenetics in human genetics and clinical diagnostics indicates that analogous applications in plants are highly feasible. One sort of application would be the identification of new aneuploids, which traditionally involves either direct karyotypic identification, which is feasible in only a few plant species, or tests with markers (cytogenetic, genetic, or molecular), which require sexual hybridization and at least one subsequent seed or plant generation. We have used meiotic fluorescence in situ hybridization (FISH) to analyze a new monosome of cotton (Gossypium hirsutum L., 2n = 4x = 52, 2(AD)1) that had a phenotype which seemed to be distinct from monosomes in the Cotton Cytogenetic Collection. Painting with A2-genome DNA revealed the monosome's D-subgenome origin. DAPI-PI staining showed that the monosome carries a major NOR, delimiting it to the major NOR-bearing chromosomes of the D-subgenome, i.e., 16 or 23. Dual-color FISH with 5S and 18S-28S rDNAs indicated that the monosome contains separate major clusters of each of these two tandemly repeated rDNA elements, thus delimiting the monosome to chromosome 23, for which the Cotton Cytogenetic Collection has previously been devoid of any sort of deficiency. Of the 26 chromosomes in the cotton genome, the Collection now provides coverage for 16 (70%) in the form of monosomy, and 20 (77%) in the form of monosomy and (or) telosomy. Use of molecular cytogenetic methods to identify a new plant aneuploid in cotton exemplifies the fact that a physicochemical karyotypic chromosome identification system is not required a priori for application of new molecular cytogenetic methods, thus indicating their potential applicability to nearly all plant species.

Subunit specificity and organ distribution of glutathione transferase-catalysed S-nitrosoglutathione formation from alkyl nitrites in the rat

Glutathione transferase (GST)-catalysed S-nitrosoglutathione (GSNO) formation from alkyl nitrites was determined with the homodimers 1-1, 2-2, 3-3, and 4-4 isolated from rat liver. The 4-4 isoform showed a high specificity for the alkyl nitrites. Total GST activities were studied in homogenates from different organs. The liver showed highest GST activity both with amyl nitrite and with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate, the activity ratio of amyl nitrite over CDNB being 3.8. In lung and heart, these ratios were 6.2 and 5.7, respectively, indicating a selectivity of these organs for alkyl nitrite metabolism and GSNO formation.

Protein engineering on subtilisin E

Protein engineering was carried out by site-directed and random mutagenesis on subtilisin E gene. Four mutants were obtained. They are M222A; M222A, N118S; M222A, N118S, Q103R; and M222A, N118S, Q103R, D60N. The mutant genes were recombined in pBE-2, an E. coli-B. subtilis shuttle vector, and transformed into B. subtilis DB104, an alkaline and neutral proteinase deficient strain. The subtilisin E mutations obtained from their gene expressions were purified. The properties of these mutants showed that the M222A mutation made the enzyme resistant to oxidation, N118S mutation increased the thermal stability, while Q103R and D60N mutations enhanced the specific activity of the enzyme but decreased the thermal stability and, in particular, D60N mutation caused the enzyme to be very unstable. The IEF-PAGE showed that the wild type and M222A mutant had the same pI of 8.92, while those of double mutant, triple mutant, and quadruple mutant were 8.88, 9.10, and 9.17, respectively. The optimum pH range was 7.5-9.5 for suc-AAPF-pNA substrate and was 10-12 for casein substrate.

Characterization of the tumor invasion area in the rat intracerebral glioma

Tumor cell invasion surrounding intracerebrally implanted tumors in rats was studied by comparing the results of cerebral microangiography, fluorescence imaging of blood-brain barrier (BBB) disruption and histopathology. Each comparison was on subsequent sections taken from an initial 1 mm coronal slice of brain taken through the cell injection site containing tumor using the RT-2 glioma model. Tumor extension was assessed at 3, 5, 7 and 9 days after tumor implantation. Analysis of the brain adjacent to tumor shows that the actual tumor cell invasion area is greater than the area of BBB disruption at later stages of tumor growth and the extent of tumor vascularization lies well within the area defined by the extent of tumor cell invasion. Furthermore, this study found that the size of the area of tumor cell invasion remains relatively stable in proportion to the solid tumor mass at various stages of growth such that the area of tumor invaded brain was approximately 2.5 times greater than the area outlined by solid tumor mass. We conclude that measurement of the solid tumor mass, tumor vascular area and region of blood-brain barrier disruption due to tumor, grossly underestimate the total tumor volume. Therapies aimed at controlling glial tumor growth must, therefore, include normal appearing regions of brain peripheral to the abnormal region defined as tumor and tumor invaded brain as defined by radiographic and imaging studies.

[High-dose chemotherapy supported by peripheral blood stem cells to treat intermediate--and high-grade non-Hodgkin's lymphomas]

In this study, 16 eligible patients with intermediate and high-grade non-Hodgkin's lymphoma were treated with a new high-dose DHACT regimen supported by rhG-CSF and peripheral blood stem cell (PBSC) rescue. PBSC were mobilized by rhG-CSF or rhGM-CSF. Single leukapheresis was performed and the PBSC were then frozen in liquid nitrogen. CFU-GM clonogenic assay for mononuclear cells and resuscitated progenitor cells done to calculate how many progenitor cells were alive after freezing. The DHACT chemotherapy was composed of carboplatin 600 mg/m2 on d1, Ara-C 1500 mg/m2 on d2, VM-26 100 mg/m2 on d3, 4, and dexamethasone 40 mg/d, on d1-4. Autologous PBSC was reinfused after 24 to 48 hours of chemotherapy. Recombinant human G-CSF at 300 micrograms administered daily on 2 successive days when the absolute neutrophil count was greater than 1 x 10(9)/L. Other supportive care procedures were standard for the unit. The median amount of PBSC reinfused into a patient was 0.9 x 10(8)/kg. The recovery rate of CFU-GM was 78% after cryopresevation. Within 7 to 9 days after high-dose DHACT chemotherapy, the WBC count and the platlet count arrived nadir, and then rose gradually with rhG-CSF injection. The median time for WBC count from nadir to > or = 1 x 10(9)/L was 4 days, and that for platelet count from nadir to > or = 50 x 10(9)/L was 7 days. Nine patients achieved complete remission and 5 patients achieved partial remission. The median follow-up on survival was 9 months. High-dose DHACT regimen supported by rhG-CSF and PBSC rescue is a safe and effective treatment for patients with advanced intermediate and high-grade non-Hodgkin's lymphoma.

Presenilin-1 polymorphism in patients with Alzheimer's disease, vascular dementia and alcohol-associated dementia in Japanese population

We investigated the genetic association between intronic polymorphism in Presenilin-1 (PS-1) gene and patients with various types of dementia such as Alzheimer's disease (AD), vascular dementia (VD) and alcohol associated dementia (ALD), in Japanese population. Homozygosity for allele 1 of the PS-1 polymorphism was significantly increased in late-onset sporadic AD, but not in early-onset sporadic AD, familial AD, VD and ALD. When late-onset sporadic AD patients were divided on the basis of apolipoprotein E (APOE) genotype, homozygosity for the allele 1 of the PS-1 polymorphism was significantly increased in patients with late-onset sporadic AD without APOE epsilon 4 allele, but not in those with APOE epsilon 4 allele. Intronic mutation in PS-1 gene may be specific and one of the genetic risk factor for late-onset sporadic AD.

Role of intracardiac angiotensin II in cardiac dysfunction of rat during septic shock

OBJECTIVE

To observe changes in the content of myocardial angiotensin II and its role in cardiac dysfunction of rat during septic shock.

METHODS

Septic shock model was produced by cecal ligation and puncture (CLP) operation on rats. Experimental rats were given captopril 15 mg.kg-1/d per os for 3 days before CLP operation. Mean blood pressure and left ventricular pressure were recorded. Myocardial angiotensin converting enzyme (ACE) activities were determined by a fluorometric assay and myocardial angiotensin II content was measured by radioimmunoassay. Highly purified membrane of sarcoplasmic reticulum (SR) was prepared from rat hearts. Assays were made of ATP-dependent Ca2+ uptake by cardiac SR and (3H) ryanodine binding to SR.

RESULTS

Myocardial angiotensin II content increased by 51.5% (P < 0.01) at the 18th hour post CLP, meanwhile there was a decrease in left ventricular +/- dp/dtmax value and the impairment in Ca2+ uptake and (3H) ryanodine binding to cardiac SR. Preliminary administration of captopril reduced myocardial ACE activity and angiotensin II content, but increased left ventricular +/- dp/dtmax value. In comparison to shock group, the initial rate and the capacity of SR Ca2+ uptake were increased by 120% (P < 0.01) and 33.9% (P < 0.05), the Bmax value of (3H) ryanodine binding to SR was also elevated, while the Kd value remained unchanged.

CONCLUSIONS

The elevated intracardiac angiotensin II, resulting from the activation of myocardial ACE during sepsis, probably serves as one of the important mediators participating in the pathogenesis of heart failure: the effects of angiotensin II may be associated with the disturbance of Ca2+ transport function of cardiac SR.

[Effects of Peucedanum praeruptorum extractum on blood pressure, left ventricular hypertrophy and hemodynamic changes in left ventricular hypertrophied hypertensive rats]

After intragastric administration of Peucedanum praeruptorum (PPE) 0.6 g/100 g body weight, the blood pressure was decreased significantly in both the normal and the left ventricular hypertrophied hypertensive (LVH) rats. The PPE could still prevent the formation of the left ventricular hypertrophy in renovascular hypertensive rats, the ratio of weight of left ventricular over the weight of body was reduced markedly than that of the LVH group, and was nearly the same of the sham-operated group. The PPE could improve both the systolic and diastolic function than that of the LVH group in the isolated heart, especially, the flow of the coronary artery was increased significantly.

Distribution of 5S and 18S-28S rDNA loci in a tetraploid cotton (Gossypium hirsutum L.) and its putative diploid ancestors

The most widely cultivated species of cotton, Gossypium hirsutum, is a disomic tetraploid (2n=4x=52). It has been proposed previously that extant A- and D-genome species are most closely related to the diploid progenitors of the tetraploid. We used fluorescent in situ hybridization (FISH) to determine the distribution of 5S and 18S-28S rDNA loci in the A-genome species G. herbaceum and G. arboreum, the D-genome species G. raimondii and G. thurberi, and the AD tetraploid G. hirsutum. High signal-to-noise, single-label FISH was used to enumerate rDNA loci, and simultaneous, dual-label FISH was used to determine the syntenic relationships of 5S rDNA loci relative to 18S-28S rDNA loci. These techniques provided greater sensitivity than our previous methods and permitted detection of six new G. hirsutum 18S-28S rDNA loci, bringing the total number of observed loci to 11. Differences in the intensity of the hybridization signal at these loci allowed us to designate them as major, intermediate, or minor 18S-28S loci. Using genomic painting with labeled A-genome DNA, five 18S-28S loci were localized to the G. hirsutum A-subgenome and six to the D-subgenome. Four of the 11 18S-28S rDNA loci in G. hirsutum could not be accounted for in its presumed diploid progenitors, as both A-genome species had three loci and both D-genome species had four. G. hirsutum has two 5S rDNA loci, both of which are syntenic to major 18S-28S rDNA loci. All four of the diploid genomes we examined contained a single 5S locus. In g. herbaceum (A1) and G. thurberi (D1), the 5S locus is syntenic to a major 18S-28S locus, but in G. arboreum (A2) and G. raimondii (D5), the proposed D-genome progenitor of G. hirsutum, the 5S loci are syntenic to minor and intermediate 18S-28S loci, respectively. The multiplicity, variation in size and site number, and lack of additivity between the tetraploid species and its putative diploid ancestors indicate that the behavior of rDNA loci in cotton is nondogmatic, and considerably more complex and dynamic than previously envisioned. The relative variability of 18S-28S rDNA loci versus 5S rDNA loci suggests that the behavior of tandem repeats can differ widely.

Separation of enantiomers of drugs by capillary electrophoresis. III. Beta-cyclodextrin as chiral solvating agent

Enantiomer separation by capillary zone electrophoresis was studied for a set of 34 chiral drugs. Keeping the concentration of beta-cyclodextrin as a chiral solvating agent as constant as possible led to the separation of seven enantiomeric pairs. Carvedilol, Tetryzoline, Tropicamide and Zopiclone gave a baseline separation, Chlorphenamine, Ketamine, and Orciprenaline a partial separation. Statistical analysis revealed that the best separation factors were observed for a medium degree of interaction with the cyclodextrin. A theory explaining this effect provides a helpful guideline for further optimization.

Evidence of hypoxia-inducible factor-1 in vascular endothelial and smooth muscle cells

The hypoxia-inducible element (HIE-1), a 50-bp region just 3' to the human erythropoietin gene, has been found to regulate transcription in cells that do not ordinarily synthesize erythropoietin. We hypothesized that the HIE-1 and associated protein factors may have a role in transcriptional regulation in hypoxic vascular tissues. Therefore, tissues of vascular origin were grown in culture and exposed to hypoxia (1% 02, 5% CO2, balance N2) or normoxia (21% O2, 5% CO2). Human microvascular endothelial cells (HMEC-1) studied with electrophoretic mobility shifting demonstrated that HIE-1 was bound to a protein induced by hypoxia in these cells. HMEC-1 and rat aortic smooth muscle cells (RASM) were transfected with the vector pGL2-HIE-1. HMEC-1 reporter gene expression was 3.7 +/- 0.5-fold increased at 12 hours and 3.7 +/- 1.3-fold increased at 24 hours by hypoxia. RASM reporter gene expression was 18.6 +/- 6.5-fold (SEM) increased at 12 hours and 2.0 +/- 0.7-fold increased at 24 hours by hypoxia. These findings provide indirect evidence of a hypoxia-inducible factor in vascular cellular transcriptional regulation.

Analysis of amyloid precursor protein mRNAs in skin fibroblasts in Down's syndrome

We examined amyloid precursor protein (APP) mRNAs expression in skin fibroblasts from Down's syndrome (DS) patients of different ages to determine the time of occurrence of abnormal splicing. The ratio of APP770 + 751 mRNA to APP695 mRNA (APP770 + 751/695) was significantly increased in the young DS group and adult DS group compared with the age-matched control groups (p < 0.01, p < 0.05), but no significant increase was observed in the aged DS group compared with the age-matched control group. These findings suggest that metabolic abnormalities of the APP gene occur at a very early stage of DS, at a mean age of about 5 years. Therefore, metabolic abnormalities of the APP gene are considered to appear at a very young age also Alzheimer's disease (AD). In this study, we confirmed that examination of the APP gene in skin fibroblasts might be useful for early diagnosis of AD.

Effects of Arg-Gly-Asp-Ser on Ca2+ transport of myocardial sarcoplasmic reticulum in rat septic shock

AIM

To study the effects of Arg-Gly-Asp-Ser (RGDS), a synthetic short peptide of fibrinogen degradation, on the Ca2+ transport function of cardiac sarcoplasmic reticulum in rat septic shock.

METHODS

RGDS 5 mumol.kg-1 was injected i.v. at 4 h and 14 h after cecal ligation and puncture (CLP) operation on rats. Highly purified membrane of sarcoplasmic reticulum (SR) was prepared from rat hearts. Assays were made of ATP-dependent Ca2+ uptake by cardiac SR and [3H] ryanodine binding to SR.

RESULTS

The initial rate and the capacity of SR Ca2+ uptake were increased by 104% (P < 0.01) and 12% (P < 0.05), respectively, paralleled by an increase in Ca(2+)-ATPase activity and a decrease in calcium accumulation of myo- cardium of septic rats, whereas the Bmax and Kd values of Ca2+ activated [3H]ryanodine binding to SR were unaffected after RGDS administration.

CONCLUSIONS

The results indicated that RGDS have cardioprotective effects of maintaining Ca2+ homeostasis of cardiac myocytes by enhancing SR Ca2+ uptake in rat septic shock.

C5a peptidase alters clearance and trafficking of group A streptococci by infected mice

Group A streptococcal C5a peptidase (SCPA) specifically cleaves the human serum chemotaxin C5a at the polymorphonuclear leukocyte (PMNL) binding site. This study tested the proposal that SCPA contributes to virulence by retarding the influx of inflammatory cells and clearance of streptococci during the first few hours after infection. To investigate the specific contribution of SCPA to the virulence of group A streptococci, scpA insertion and deletion mutants were created by directed plasmid insertion into scpA and gene replacement. The precise locations of insertion and deletion mutations were confirmed by PCR and DNA sequence analysis. The impact of mutation on virulence was investigated with a mouse air sac model of inflammation. Experiments evaluated clearance of streptococci from the air sac within 4 h after infection. SCPA- streptococci were cleared more efficiently than wild-type bacteria. Localization of streptococci in lymph nodes and spleens of infected mice revealed a significant difference between mutant and wild-type streptococci. PMNLs and other granulocytes that infiltrated the air sac were quantitated by single-color flow cytometry. The total cellular infiltrate was greater and PMNLs dominated the granulocytic infiltrates of air sacs inoculated with SCPA- mutant bacteria. The data obtained are consistent with the possibility that SCPA- streptococci are initially cleared from the site of infection primarily by PMNLs. Moreover, mutant and wild-type streptococci followed different paths of dissemination. SCPA- bacteria were transported to lymph nodes, whereas wild-type streptococci avoided transport to the lymph nodes and rapidly spread to the spleen.

Microsomal formation of S-nitrosoglutathione from organic nitrites: possible role of membrane-bound glutathione transferase

The formation of S-nitrosoglutathione (GSNO) from amyl nitrite and n-butyl nitrite was studied in rat liver microsomes, employing N-ethylmaleimide (MalNEt) as an activator and indomethacin as an inhibitor of microsomal glutathione S-transferase (GST). Rates were compared with GST activity measured with 1-chloro-2,4-dinitrobenzene (CDNB) as a substrate. MalNEt stimulated GST activity and the formation of GSNO from amyl nitrite and n-butyl nitrite about 10-fold. Increasing concentrations of indomethacin inhibited both reactions in parallel. N-Acetyl-L-cysteine but not L-cysteine could substitute for GSH. It is concluded that rat liver microsomal GST catalyses the formation of GSNO from amyl nitrite and n-butyl nitrite. The activity of the MalNEt-stimulated microsomal GST is calculated to be about 17 units/mg of enzyme with the alkyl nitrites and about 16 units/mg of enzyme with CDNB as a substrate, assuming that 3% of microsomal protein is GST. These rates are comparable with those obtained for cytosolic GSTs. Thus microsomal GST may play a significant role in the metabolism of alkyl nitrites in biological membranes.

[Effects of m-Nif and Nif on left ventricle hypertrophy in rats induced by partial ligation of abdominal aorta]

Partial ligation of the abdominal aorta of rats was adopted to induce left ventricle hypertrophy (LVH). The effects of m-nifedipine (m-Nif) and nifedipine (Nif) on prevention of hypertrophy and the possible mechanism were investigated. The wet weights of the left ventricle (WWLV) of the LVH group were increased compared with those of the sham operated group. After treatment with m-Nif and Nif for 4 wks, the WWLV decreased by 25% +/- 9% and 16% +/- 9%, respectively. The pressure-volume (P-V) curve of the hypertrophied group was markedly elevated, which means that the myocardial compliance was decreased, and the stiffness coefficient of the hypertrophied group was significantly elevated than that of the sham operated group, but the groups treated with m-Nif or Nif were significantly improved. The characteristics of the left ventricular myocardial DHP binding sites were studied. The results showed that the Kd and the Bmax were similar in the m-Nif, Nif and hypertrophied groups, but the total number of the DHP receptors (TNR) of the LVH group was markly increased than that of the sham operated group, but the TNR of the m-Nif and Nif groups were the same as that of the sham operated group. These results suggest that the effects of m-Nif and Nif on preventing cardiac hypertrophy and improving myocardial compliance may be related to their depressing the TNR of DHP.

Tangential migration of luteinizing hormone-releasing hormone (LHRH) neurons in the medial telencephalon in association with transient axons extending from the olfactory nerve

During embryonic development, luteinizing hormone-releasing hormone (LHRH) neurons migrate to the brain from the medial olfactory epithelium through the olfactory nerve. LHRH neurons enter the brain and migrate tangentially along the medial edge of the telencephalon in close association with a neural cell adhesion molecule (N-CAM) enriched fiber bundle. In the current work we wished to determine whether this N-CAM enriched fiber bundle is an extension of the olfactory nerve. Ablation experiments, immunocytochemistry and diI implants all suggest that LHRH neurons migrate in association with a very small subset of transient N-CAM enriched neuronal processes which extend out of the olfactory nerve proper to the septal-preoptic area.

[Effects of taurine and enalapril on blood pressure, platelet aggregation and the regression of left ventricular hypertrophy in two-kidney-one-clip renovascular hypertensive rats]

In two-kidney-one-clip (2k-1c) renovascular hypertensive rats, the blood pressure, left ventricular weight/body weight (LVW/BW) ratio and blood platelet aggregation were increased significantly. Enalapril (Ena) 6 mg . kg-1 . d-1 ig 9 wk and Taurine 30 mg . kg-1 . d-1 ig 9 wk can not only decrease the high blood pressure, LVW/BW ratio, but also the blood platelet aggregation induced by ADP or thrombin, though still different from that of the normal group. When the 2k-1c renovascular hypertensive rats were treated with both Ena and Tau, the blood pressure and blood platelet aggregation were decreased to the same as that of the normal group, and the LVW/BW ratio was also lowered markedly, though still higher than that of the normal group. These results show that both Ena and Tau can reverse the left ventricular hypertrophy, decrease the blood pressure and suppress the blood platelet aggregation in 2k-1c renovascular hypertensive rats. When treated with both drugs, the effects can be improved. It suggests that the two drugs can enhance the effects when used together, and that they may be two good agents for treatment of hypertension.

[Impaired calcium uptake by cardiac sarcoplasmic reticulum and its underlying mechanism during rat septic shock]

The underlying mechanism of Ca2+ uptake function of cardiac sarcoplasmic reticulum (SR) was investigated in the rat septic shock model produced by cecal ligation and puncture (CLP). The results are as follows. During the early phase of sepsis, the initial rate of ATP-dependent Ca2+ uptake by SR was decreased, while both the capacity of Ca2+ uptake and the activity of Ca(2+)-ATPase were unaffected. In the late sepsis, the impairment in SR function was even greater as the initial rate and the capacity of Ca2+ uptake by SR were significantly decreased, and this was paralleled by a reduction in Ca(2+)-ATPase activity. Although Ca2+ affinity (Km value) to calcium pump and the A0.5 values for Mg2+ and ATP activation on the Ca2+ uptake rate were unchanged, during sepsis the phosphorylation of SR vesicles by adding of catalytic subunit of the cAMP-dependent protein kinase (PKA), calmodulin, or the fragment of PKC into Ca2+ uptake buffer, failed to stimulate Ca2+ uptake activities of SR isolated from early or late septic rats. These data suggest that depression of cardiac SR function is aggravated as sepsis develops, the impairment of SR Ca2+ uptake is possibly based on a mechanism of defective phosphorylation of SR rather than the ionic and energic regulatory actions of Ca2+, Mg2+, ATP on cardiac SR.

[Altered ryanodine receptor of rat cardiac sarcoplasmic reticulum and its underlying mechanism during septic shock]

The present study was undertaken to observe the changes of Ryanodine receptor of cardiac junctional sarcoplasmic reticulum (SR) in relation to membrane lipid microenvironment alteration during septic shock. The results showed that the Bmax for 3H-ryanodine binding to cardiac junctional SR was decreased by 41.3% (3.9 +/- 0.1 vs. sham 6.6 +/- 0.7 pmol/mg, P < 0.01) while the Kd value was unaffected during late septic shock (CLP 18 h). Ca2+ activated 3H-ryanodine binding significantly and reached a saturation value when Ca2+ concentration was 5 x 10(-5) mol/L, while the S0.5 and the Hill coefficient values remained unchanged during septic shock. Caffeine, ATP, and AMP-PCP activated while Mg2+, ruthenium red inhibited 3H-ryanodine binding in both groups but the A0.5 (concentration requires for half maximum activation) and the IC50 (concentration requires for half-maximum inhibition) for the above mentioned activators and inhibitors, were respectively unaffected during septic shock. Digestion of cardiac SR isolated from control rats with phospholipase A2 inhibited 3H-ryanodine binding, which could be dramatically recovered by the incorporation of phosphatidylcholine (PC), or phosphatidylserine (PS), or phosphatidylethanolamine (PE) into the isolated cardiac SR. Incorporation of above phospolipids into SR isolated from septic rats reversed shock-induced inhibition of 3H-ryanodine binding. It is concluded that the mechanism responsible for the inhibition of 3H-ryanodine binding of junctional SR during septic shock may be related to modification of membrane lipid microenvironment in response to PLA2 overactivation during septic shock.

An extensive subfrontal approach to the lesions involving the skull base

A modification of the transbasal approach of Dorome called extensive subfrontal approach and the surgical results with this approach in 22 cases are presented. Bilateral frontal craniotomies incorporated with the removal of orbital ridges and part of the orbital roofs were fashioned en bloc. It may give rise to good exposure of the midline lesions of the anterior, middle and posterior skull base, minimizing the need for the retraction of frontal lobes. There was no surgical mortality in this series of cases. Of the 20 cases with tumors, total resections were achieved in 11 cases, subtotal or large resections in 4 cases and partial resection in one case. Two patients with spontaneous rhinorrhea were successively treated surgically. 21 patients had a follow-up with a time ranging from 1-11 years (a mean of 3 years). 15 patients resumed their jobs with no evidence of recurrence of the original disease, and 5 patients able to live self-care. One patient with an olfactory neuroblastoma died 3 years after the operation owing to relapse of the tumor.

Properties of an N-terminal proteolytic fragment of apolipoprotein AI in solution and in reconstituted high density lipoproteins

Limited proteolysis was used to study the domain structure and to produce a large N-terminal fragment of human apolipoprotein AI (apoAI). Digestion of reconstituted high density lipoprotein (rHDL) prepared with apoAI and dipalmitoyl phosphatidylcholine or palmitoyloleoyl phosphatidylcholine by chymotrypsin, trypsin, elastase, and subtilisin generated a major fragment of 22 kDa. Under milder conditions proteolysis of lipid-free apoAI produced a fragment of similar size. The fragments shared the same N terminus as intact apoAI, and the chymotryptic fragment had a molecular weight of 22,384 as determined by electrospray ionization mass spectrometry. Thus the fragment consists of the N-terminal 192 amino acid residues of apoAI, and the region around Tyr192 seems to be especially accessible to proteases. In aqueous solution the fragment, apoAI-(1-192), had an alpha-helix content similar to that of apoAI (approximately 52%) but existed only as monomers and dimers. ApoAI-(1-192) lysed dimyristoyl phosphatidylcholine liposomes slowly compared with apoAI but did form rHDL complexes with palmitoyloleoyl phosphatidylcholine or dipalmitoyl phosphatidylcholine when prepared by the sodium cholate dialysis method. ApoAI-(1-192) rHDL exhibited sizes and size distributions distinct from apoAI rHDL but displayed similar stability against denaturation. The isolated apoAI-(1-192) rHDLs retained a high ability to activate lecithin-cholesterol acyltransferase, comparable with the most effective apoAI rHDL. The results suggest that the C-terminal domain of apoAI is crucial for self-association and initial lipid binding but is not involved in specific lecithin-cholesterol acyltransferase activation.

Purification and partial amino acid sequences of a new presynaptic toxin and a cytotoxin from venom of pit veper Agkistrodon blomhoffii brevicaudus

The technique of the reverse-phase performance liquid chromatography (RP-HPLC) was employed to separate and purify the toxic proteins from the venom of Agkistrodon blomhoffii brevicaudus collected in China. 3 toxic proteins marked as AgTx-1, AgTx-2 and AgTx-3 consisting of about 122 amino acid residues were screened. The toxicities (LD50) of the AgTx-1, AgTx-2 and AgTx-3 were 0.075, 0.51 and 6.6 mg per kg weight of mice respectively. Toxicological experiment in the chick biventer cervicis nerve-muscle preparation showed that the acetylcholine (Ach) sensitivity of the preparation was unchanged after the total failure of the indirect contraction caused by AgTx-1 and AgTx-2, suggesting that they were presynaptic blockers, namely beta-type of snake toxins. However, the amplitude of indirect contraction of the preparation was gradually reduced due to its incomplete relaxation caused by AgTx-3, indicating that it should belong to the category of cytotoxins. The partial amino acid sequences of 3 toxins have been established. It was found in ref. [1] that the sequences of the first 32 N-terminal amino acid residues of AgTx-1 and AgTx-2, as well as beta-agkistrodotoxin (beta-AgTx) reported previously were identical (the residue at the position 30 of beta-AgTx should be Trp). In view of the similarity in toxicities, and the amounts in the venom and other properties, it was concluded that AgTx-1 should be beta-AgTx and consequently was renamed beta 1-AgTx. AgTx-2 should be the isoform of beta 1-AgTx, and correspondingly named beta 2-AgTx.

[Effect of the changes of amino acids on both signal peptide C-terminal and mature protein N-terminal region to the secretion of alpha-amylase in B. subtilis]

By site-directed mutagenesis, G and C have taken the place of T and G at nucleotide sequence 287 and 291 of B. licheniformis alpha-amylase gene to generate pAm-y413B and the N-terminal sequence of mature protein have been changed from 7Leu 8Met to 7Arg8Ile. By the insertion of polylinker into the C-terminal of the signal sequence of alpha-amylase gene of pAmy413, the signal peptide of alpha-amylase produced by pAmy413L is 13 amino acids more than the pAmy413 (which is 29 amino acids long) and also, a new recognition cleavage sequence for signal peptidase I (Ala-Gln-Ala decreases Ser) is created; The secondary structure of the signal peptide has been analyzed by computer programs. The alpha-amylase relative activity of the two mutant strains is 3% and 36% of pAmy413, respectively. The molecular weight of extracellular alpha-amylase is the same as pAmy413. Terminal analysis shows that the N-terminal amino acid of mature protein is Ala, not Ser, and suggests that SPase I prefers to cleavage at the wild type recognition site (Ala-Ala-Ala decreases Ala). Therefore, all of the above results show that the secretion of alpha-amylase in B. subtilis is in accordance with the co-translational transportation model.

Toxicity of photodynamic therapy with photofrin in the normal rat brain

The widespread acceptance of photodynamic therapy (PDT), a potential adjuvant brain tumor therapy under clinical evaluation since 1980, has been partially restrained by its potential toxicity toward normal brain tissue. This study examined PDT-produced injury of normal rat brain as a function of photosensitizer dose. Brain injury was characterized by correlating measurements of the area of cerebral edema using T2-weighted magnetic resonance images, measurement of brain water content at the lesion site, microscopic examination of histological sections through the PDT lesion, and by evaluation of the area of blood brain barrier (BBB) disruption using computerized morphometric analysis of the region of Evans blue (EB) dye-labelled albumin extravasation. Monochromatic red light (630 nm) was delivered intracerebrally using a 5-mm-long cylindrical, diffusion-tip optical fiber at a constant energy dose of 15 joules. A Photofrin dose of 2 mg/kg of body weight produced a transient breakdown in the blood brain barrier around the site of the implanted optical fiber demonstrated by magnetic resonance imaging (MRI), extravasation of EB dye and pallor on hematoxylin and eosin-stained microscopic tissue sections. A much larger area of BBB disruption was seen at a dose of 4 mg/kg of Photofrin, and this drug dose resulted in significant permanent brain injury. In this model, a Photofrin dose of 4 mg/kg body weight is not tolerated by the normal brain.

[Effects of 6-(alpha alpha-diphenylacetylpiperazinyl) phenyl-5-methyl-4,5-dihydro-3 (2H)-pyridazinone on rabbit platelet aggregation and TXB2, cAMP production]

6-(alpha alpha-diphenylacetylpiperazinyl) phenyl-5-methyl-4,5-dihydro-3 (2H)-pyridazinone (DMDP) is a new synthetic pyridazinone derivative. This compound was shown to inhibit AA, ADP and PAF-induced rabbit platelet aggregation, and its IC50s were found to be 1.12 +/- 0.1, 4.19 +/- 0.5 and 2.97 +/- 0.1 mumol/L, respectively. At the concentration range of 1-500 mumol/L, the compound was found to depress TXB2 content and to increase cAMP levels in washed rabbit platelets in a dose-dependent manner. These might be the mechanisms of the compound on the inhibition of rabbit platelets.

Improved survival from intracavitary photodynamic therapy of rat glioma

The effectiveness of intratumoral photoradiation in photodynamic therapy (PDT) using a polyporphyrin photosensitizer was studied in the RT-2 rat glioma model. One week after intracerebral implantation of RT-2 cells, experimental rats received a single i.p. injection of 2 mg/kg of Photofrin. After administration of the photosensitizer (48 h), the tumors were partially resected and the exposed cavity was irradiated with 15 J of laser light at a wavelength of 630 nm. Further treatment with a large craniectomy significantly enhanced rat survival. Control rats which received no photosensitizer but were treated with surgery, alone or in combination with laser irradiation, succumbed from early tumor recurrence. Photodynamic therapy without decompressive surgery resulted in hemorrhagic infarction of residual tumor and adjacent brain with focal cerebral edema which resulted in cerebral herniation and early death. Our results indicate that photodynamic therapy is effective in treating residual brain tumor but at the expense of brain tissue surrounding the tumor. Unless relieved, intracranial pressure from photodynamic therapy-associated cerebral edema in this animal model resulted in shortened survival.

Relation between polyporphyrin distribution and blood brain barrier changes in the rat glioma model

Photofrin (a polyporphyrin mixture) distribution in a rat glioma model was studied in relation to changes in the blood brain barrier (BBB). At selected intervals after intraperitoneal injection of Photofrin, the concentration of polyporphyrins (PP) and Evans Blue Dye, an indicator of BBB permeability, were determined for tumor, brain adjacent to tumor (BAT), and normal brain tissue. Contrary to earlier reports of maximal accumulation at 4-24 hours, tumor levels of PP increased throughout the 96 hour measurement period. During the early stages of tumor development, PP uptake by tumor appeared to be less correlated to BBB disruption. We conclude that passive diffusion through an incompetent BBB does not completely explain PP accumulation in tumor tissue.

Interstitial photoradiation injury of normal brain

The effect on normal brain of continuous interstitial laser irradiation at 630 nm through an implanted cylindrical-shape, diffusion-tipped optical fiber was studied in the rat. Brain water content in the laser irradiation area (LIA) and Evans blue (EB) dye content in selected areas of the brain were measured for different laser power outputs from 0 to 250 mW after 5 minutes of photoradiation. The degree and nature of tissue damage was examined histologically and correlated with the laser power level. There is significant brain damage, blood brain barrier (BBB) disruption, and brain edema in LIA for laser power outputs in excess of 100 mW from the diffusion tip (p less than 0.001). Brain edema in the LIA is strongly correlated with BBB disruption indicated by the presence of EB. Histologically, the cortical surface was more susceptible than deeper white matter regions to interstitial laser irradiation. Possible indirect mechanisms of brain injury from interstitial laser irradiation are discussed.