Dietary L-arginine attenuates expression of vascular cell adhesion molecule-1 in the aortae of hypercholesterolemic rats

OBJECTIVE

To determine whether the antiatherogenic effect of L-arginine is due to an inhibition of vascular cell adhesion molecule-1 (VCAM-1) expression in the aortae of hypercholesterolemic rats.

METHODS

Twenty-four male Wistar rats were randomized into three groups: Group NC with normal diet (NC, n = 8), Group CC with 4% cholesterol and 1% cholic acid diet (CC, n = 8), Group AC with 4% cholesterol and 1% cholic acid diet supplemented with 3% L-arginine HCl in the drinking water (AC, n = 8). Eight weeks later, the blood samples were collected for biochemical studies, and the aortae were harvested for RT-PCR and immunohistochemical studies.

RESULTS

The results showed that dietary L-arginine supplementation reduced expression of VCAM-1 in protein level and mRNA level.

CONCLUSION

Inhibitory effect of dietary supplementation of L-arginine on VCAM-1 expression may be one of the mechanisms of its antiatherosclerosis.

Brain segmentation and the generation of cortical surfaces

This paper describes methods for white matter segmentation in brain images and the generation of cortical surfaces from the segmentations. We have developed a system that allows a user to start with a brain volume, obtained by modalities such as MRI or cryosection, and constructs a complete digital representation of the cortical surface. The methodology consists of three basic components: local parametric modeling and Bayesian segmentation; surface generation and local quadratic coordinate fitting; and surface editing. Segmentations are computed by parametrically fitting known density functions to the histogram of the image using the expectation maximization algorithm [DLR77]. The parametric fits are obtained locally rather than globally over the whole volume to overcome local variations in gray levels. To represent the boundary of the gray and white matter we use triangulated meshes generated using isosurface generation algorithms [GH95]. A complete system of local parametric quadratic charts [JWM+95] is superimposed on the triangulated graph to facilitate smoothing and geodesic curve tracking. Algorithms for surface editing include extraction of the largest closed surface. Results for several macaque brains are presented comparing automated and hand surface generation.

Murine natural killer T(NKT) cells [correction of natural killer cells] contribute to the granulomatous reaction caused by mycobacterial cell walls

Mice injected with deproteinized cell walls prepared from the strain H37rv of Mycobacterium tuberculosis develop a granuloma-like lesion in which NKT cells are predominant. NKT cells play a primary role in the granulomatous response, because the latter does not occur in Jalpha281(-/-) mice, which miss NKT cells. The glycolipidic fraction of the cell walls is responsible for the recruitment of NKT cells; the recruiting activity is associated with fractions containing phosphatidylinositolmannosides. These results define a powerful experimental set up for studying the in vivo induction of NKT cell responses to microbial components.

Estimating AIDS incidence and jack-knife variance from a continuous delay distribution and incomplete data

Usual methods for estimating AIDS incidences are based on the inflation of a discrete reporting delay distribution, which often results in very imprecise estimates of the incidence in the most recent past. In this paper, we propose an alternative approach to estimate the AIDS incidence by inflating a continuous reporting delay distribution for each reported case. Covariate effects on reporting delays are evaluated by a proportional hazards model for the reverse time hazard function. A jack-knife variance for the estimated AIDS incidence is given. Study results showed that precision of estimates is improved by using the continuous time model as compared with those estimates given by its discrete counterpart. This feature is useful in assessing current trends in AIDS incidence.

Responses of sympathetic outflow to skin during caloric stimulation in humans

We previously showed that caloric vestibular stimulation elicits increases in sympathetic outflow to muscle (MSNA) in humans. The present study was conducted to determine the effect of this stimulation on sympathetic outflow to skin (SSNA). The SSNA in the tibial and peroneal nerves and nystagmus was recorded in nine subjects when the external meatus was irrigated with 50 ml of cold (10 degrees C) or warm (44 degrees C) water. During nystagmus, the SSNA in tibial and peroneal nerves decreased to 50 +/- 4% (with baseline value set as 100%) and 61 +/- 4%, respectively. The degree of SSNA suppression in both nerves was proportional to the maximum slow-phase velocity of nystagmus. After nystagmus, the SSNA increased to 166 +/- 7 and 168 +/- 6%, respectively, and the degree of motion sickness symptoms was correlated with this SSNA increase. These results suggest that the SSNA response differs from the MSNA response during caloric vestibular stimulation and that the SSNA response elicited in the initial period of caloric vestibular stimulation is different from that observed during the period of motion sickness symptoms.

Chromosomal clues to the development of prostate tumors

BACKGROUND

Cytogenetic, molecular cytogenetic, and molecular studies of prostate cancer have revealed an enormous amount of data regarding chromosomal loci that are aberrant in prostate tumors.

METHODS

These data have been compared and condensed in this review to determine which chromosomes and chromosome sites have been most frequently reported.

RESULTS

Loss of the Y chromosome, gain of 7, 8, and X, and interstitial deletions on 6q, 7q, 8p, 10q, 13q, 16q, 17q, and 18q are the most prevalent.

CONCLUSIONS

A potential model for genetic control of tumor progression is presented, as are data regarding the evaluation of a new series of tumors.

In vitro susceptibility of Helicobacter pylori to trifluoromethyl ketones

Heteroaromatic trifluoromethyl ketones (TFMK's) showed strong inhibitory activity against Helicobacter pylori. The MIC50 observed for 2-trifluoroacetonylbenzoxazole (1) is 20-fold more active than metronidazole and is only twice as high as that of clarithromycin. The inhibitory mode of TFMK's on Hp growth was not related to inhibition of urease.

The second BRCT domain of BRCA1 proteins interacts with p53 and stimulates transcription from the p21WAF1/CIP1 promoter

Inherited mutations in the breast and ovarian cancer susceptibility gene BRCA1 are associated with high risk for developing breast and ovarian cancers. Several studies link BRCA1 to transcriptional regulation, DNA repair, apoptosis and growth/tumor suppression. BRCA1 associates with p53 and stimulates transcription in both p53 dependent and p53-independent manners. BRCA1 splice variants BRCA1a (p110) and BRCA1b (p100) associates with CBP/p300 co-activators. Here we show that BRCA1a and BRCA1b proteins stimulate p53-dependent transcription from the p21WAF1/CIP1 promoter. In addition, the C-terminal second BRCA1 (BRCT) domain is sufficient for p53 mediated transactivation of the p21 promoter. Previous studies emphasized the importance of the BRCT domain, which shows homology with p53 binding protein (53BP1), in transcriptional activation, growth inhibition and tumor suppression. Our findings demonstrate an additional function for this domain in protein-protein interaction and co-activation of p53. We also found that BRCA1a and BRCA1b proteins interact with p53 in vitro and in vivo. The p53 interaction domain of BRCA1a/1b maps, in vitro, to the second BRCT domain (aa 1760-1863). The BRCT domain binds to the central domain of p53 which is required for sequence specific DNA binding. These results demonstrate for the first time the presence of a second p53 interaction domain in BRCA1 proteins and suggests that BRCA1a and BRCA1b proteins, like BRCA1, function as p53 co-activators. This BRCT domain also binds in vitro to CBP. These results suggest that one of the mechanisms by which BRCA1 proteins function is through recruitment of CBP/p300 associated HAT/FAT activity for acetylation of p53 to specific promoters resulting in transcriptional activation.

Attenuation of regional differentiation of sympathetic nerve activity during sleep in humans

The purpose of the present study was to clarify how the regional differentiation of sympathetic nerve activity (SNA) is modified during natural sleep in humans. In humans, muscle and skin sympathetic nerve activities (MSNA, SSNA) have been reported to discharge independently according to a regional differentiation of SNA during wakefulness. However, in natural sleep, MSNA and SSNA have been documented to synchronize during sleep stage 2 (Rechtschaffen and Kales). In the present study, we measured MSNA and SSNA simultaneously using a double recording technique of microneurography in eight healthy volunteers during natural sleep, and analyzed how MSNA and SSNA can be synchronized. We found that the synchronicity of MSNA and SSNA was accelerated in correlation with the deepening of the non-rapid eye movement (nonREM) sleep stages. We also documented that the burst properties of MSNA different from those of SSNA in wakefulness become similar to those of SSNA in the sleep stage, and MSNA synchronizes with SSNA. The synchronicity of MSNA and SSNA is presumably caused by a reduced effect of central inhibitory baroreflex pathways on MSNA during nonREM sleep. The present findings suggest that the regional differentiation of sympathetic nerve activity is attenuated with the deepening of nonREM sleep stages.

[Loss of heterozygosity and microsatellite instability in the region including BRCA1 of breast cancer in Chinese]

OBJECTIVE

To shed light on the relationship between BRCA1 gene and breast cancer in Chinese Han women.

METHODS

Four microsatellites DNA (D17S855, D17S579, D17S1327 and THRA1) within the BRCA1 gene were used as polymorphic markers. A study of loss of heterozygosity(LOH) and microsatellite instability(MSI) at the above- mentioned 4 microsatellites of 50 breast cancer patients was conducted by using PCR -PAUGE-DNA silver staining (polymerase chain reaction-polyacrylamide urea gel electrophoresis) method.

RESULTS

Twenty-nine or 58% of the informative cases showed LOH; 35.71%, 15. 38%, 18.18%, and 26.19% of the informative cases showed positive LOH at the D17S855, D17S579, D17S1327 and THRA1 loci respectively. The rate of MSI was 46%, and the rates of MSI at the four loci were 16%, 18%, 18% and 12% respectively. Further study on the associations between the phenomena of LOH and MSI and different clinical stages revealed that MSI was an early event in mammary tumorigenesis while LOH occurred at a later stage.

CONCLUSION

All of these suggest that breast cancer in Chinese be somehow linked to BRCA1.

Phosphorylcholine-coated metallic stents in rabbit iliac and porcine coronary arteries

The arterial wall reaction to phosphorylcholine-coated metal stents was examined in rabbits and pigs. Compared to non-coated stents, no significant difference was found by angiography and histology. We conclude that although phosphorylcholine-coating does not provoke arterial neointima formation or decrease luminal diameter compared to stainless steel stents, the coating does not seem to reduce restenosis.

The effect of bu shen sheng xue fang on beta-thalassemia at gene level

Isoelectrofocusing electrophoresis, PCR-SSCP analysis with DNA direct sequencing and RT-PCR were used to analyze the constituents of hemoglobin, determine the pattern of globin gene mutation, and detect its mRNA transcription extent. The results indicated that Bu Shen Sheng Xue Fang (BSSXF) significantly increased the contents of hemoglobin (Hb) and fetal hemoglobin (HbF), and the chain ratio in patients with beta-thalassemia. The drug is markedly effective in heterozygous, but not effective in homozygous or genetic compound patients. It was suggested that the beta-globin gene defects were compensated by elevating the gamma/beta + gamma ratio, promoting the transcription and expression of gamma-globin gene in synthesizing HbF.

Changes in muscle sympathetic nerve activity and effect of breathing maneuvers during microgravity induced by parabolic flight in humans

This study aimed to clarify how muscle sympathetic nerve activity (MSNA) in humans, which plays an important role in blood pressure control against gravity, is altered under microgravity (microG) conditions, and how the MSNA change is modified by breathing maneuvers. Ten subjects seated themselves in a jet aircraft with their knees extended. MSNA was recorded microneurographically from the left tibial nerve with simultaneous monitoring of ECG, blood pressure, respiration, and intrathoracic blood volume estimated by the impedance method during parabolic flight in a jet aircraft. In half of the parabolas, their respiration was controlled at 0.25 Hz by a metronome.

RESULTS

MSNA was enhanced under hypergravity just before microG entry, and immediately suppressed by microG induced by parabolic flight. The suppression was more marked with controlled than with uncontrolled respiration (51.6 +/- 7.2 vs 82.8 +/- 2.5%, mean +/- SE, 1G=100%). MSNA changes during microG correlated significantly to changes in blood pressure and intrathoracic blood volume. The blood pressure fall 10 to 15 sec after microG entry was less prominent with controlled than with uncontrolled respiration. We conclude that changes in arterial blood pressure and intrathoracic blood volume modulate MSNA during microG induced by parabolic flight, depending largely on breathing maneuvers.

Epidemiological, clinical and serological studies on trichinellosis in Henan Province, China

The epidemiological, clinical and serological studies on human trichinellosis in Henan Province were carried out from January 1992 to December 1996. The results showed that 467 patients attending our department came from 12 administrative areas and cities of the Province and they acquired the infection mainly by eating undercooked dumplings, tasting the raw pork filling for dumplings, ingesting scalded pork or mutton. There was the high incidence season of trichinellosis during the winter. Most of the patients were workers, officers and merchants aged 20-49 years, and the incidence was higher in males than in females. The main clinical manifestations of trichinellosis were fever, general myalgia, muscle tiredness and eosinophilia. Most of the patients had not any gastrointestinal symptoms and rash. Eyelid edema was only seen in the early courses of the disease. Eosinophil count increased with time, reached to the peak 3 weeks and decreased markedly 6 weeks after the onset of the disease. Eosinophil levels elevated obviously 1 week after therapy, began to drop rapidly 2 weeks after therapy, and decreased to a near normal levels 4 weeks after therapy. Anti-Trichinella antibodies were detected by IFAT using the frozen sections of the purified T. spiralis larvae as antigen. The specific antibodies were observed in only 70.2% of patients one week after onset of disease, and increased to 91, 94.3, and 100%; 2, 3, and 4 weeks, respectively after the onset. The antibody positive rate was evidently increased to 100% 1 week after therapy with abendazole, then decreased to 25% 4 months after therapy.

MR imaging in rat glioma model and gene therapy using EGFR antisence RNA

OBJECTIVE

To study the value of 1.5T MRI in long-term follow-up of rat C6 glioma model and the efficacy of EGFR antisence RNA therapy in vivo.

METHODS

Forty-three male Wistar rats, weighing 150 to 200 g, were used for this study. They were divided into four groups: group I (7 normal rats); group II (16 rats inoculated C6 cells in the right caudate nucleus); group III (12 rats with the C6 gliomas treated with EGFR antisence RNA by in site injection); and group IV (8 rats inoculated C6 cells transfected with EGFR antisence RNA in the right caudate nucleus). Group I was examined by plain and enhanced MR scanning. Group II-IV were followed up by plain and enhanced MR scanning and were sacrificed in variable time points for pathological examination.

RESULTS

Cerebral hemispheres of normal rat were shown clearly on the MR image. The tumor could be seen about 1 week after inoculation. According to the findings on the follow-up MR scan, we could observe growth of the tumor or its regression after treatment. The tumor growth was significantly inhibited in group III and group IV as compared to those in group II.

CONCLUSION

The growth of the rat C6 glioma model and its change after treatment could be shown clearly in 1.5T MR imaging; EGFR antisence RNA significantly inhibited the growth of glioma in vivo.

Chromosome 7 abnormalities in prostate cancer detected by dual-color fluorescence in situ hybridization

Aneusomy of chromosome 7 and loss at 7q (especially 7q31.1) have been reported in prostate cancer. To further investigate abnormalities of 7q and the relationship with whole chromosome 7 changes, we have conducted a dual-color fluorescence in situ hybridization (FISH) analysis on isolated nuclei from 28 primary prostate cancers. A pericentromeric probe for chromosome 7, five newly isolated sequence-specific bacterial artificial chromosome (BAC) probes from 7q31.1, and one BAC for the epidermal growth factor receptor (EGFR) gene at 7p12 were used in dual color hybridizations. Pericentromeric probes for chromosomes X and 4 were also used as controls. Sixteen (57.1%) of the 28 tumors showed clonal aberrations. Nine of them were trisomy 7 and four were hypertetrasomy for chromosome 7. Deletions at 7q31.1 were found in two of the high grade tumors. With the exception of these two cases, all other cases showed concordant results using all probes. These findings confirm previous studies that aneusomy of 7 is associated with prostate cancer progression, and there may be a tumor suppressor gene (TSG) at 7q31.1 which is associated with tumor progression. In addition, our study indicates: (1) the deletion pattern of individual nuclei infers that deletions at 7q31.1 precede reduplications of chromosome 7; and (2) the amplification of EGFR was not detected at the DNA level, suggesting that activation of this oncogene may play a minor role in prostate cancer.

Hypoglycemic effect of water-soluble polysaccharide from Auricularia auricula-judae Quel. on genetically diabetic KK-Ay mice

The hypoglycemic effect of water-soluble polysaccharide(FA) from fruiting bodies of Auricularia auricula-judae Quel. was investigated on genetically diabetic mice (KK-Ay) from 10 to 14 weeks of age. Male mice were divided into 3 groups, the control group and FA-fed group having free access to the control diet or FA diet (30 g of FA/kg of diet). The food-restricted group had restricted access to the control diet at the level of the diet consumed by the FA-fed group. Compared with the control group, FA supplementation had a significant effect in lowering plasma glucose, insulin, urinary glucose, and food intake. FA administration also increased the tolerance to intraperitoneal glucose loading and the hepatic glycogen content. In the food-restricted group, the reduced food intake slightly lowered the plasma and urinary glucose levels, but did not improve hyperinsulinemia and glucose tolerance. This study shows that FA had a hypoglycemic effect on KK-Ay mice, and the reduced food consumption was not a major factor which contributed to the hypoglycemic action of FA.

Sympathetic nerve response to muscle during anteroposterior acceleration in humans

This study aimed to elucidate the effects of linear acceleration on muscle sympathetic nerve activity (MSNA) in humans. Eight healthy young male volunteers were seated in a linear accelerator (sled) during the recording of their electrocardiogram, blood pressure with the Finapres, thoracic impedance and respiration curve. MSNA was recorded from the tibial nerve by microneurography. At a fixed distance of sled movements in an anteroposterior direction, eight modes of stimulation with peak accelerations at 0.05, 0.10, 0.15, and 0.20 G (gravity) in sinusoidal or step mode were applied to each subject. Each movement was repeated for 5 cycles. Both the total activity and the burst rate of MSNA decreased during acceleration, and the level of the decrease was proportional to the level of the acceleration, whereas the average heart rate, thoracic impedance and mean arterial pressure did not change significantly. These results suggests that moderate linear acceleration may suppress MSNA in humans.

[Time resolved photoluminescence of PPV derivatives/C60 combination system]

We report the integrated and picosecond time-resolved photoluminescence (TRPL) measurement from two kinds of combination films: Poly(2-methoxy-5-(4-butenyloxy)phenylene vinylene) (MB-PPV)/C60 and Poly (2-methoxy-5-(4'-bromo-butoxy) phenylene vinylene) (MBB-PPV)/C60. Comparing with the pure MBB-PPV film, PL weakening and quenching of MBB-PPV were observed in the multilayer and mixed MBB-PPV/C60 films respectively. From TRPL spectra, the change of PL decay lifetime could be clearly seen, those could be attributed to the excitation transfer (ET) process between the excited MBB-PPV molecule and C60 molecule. Further measurements indicate that there is no noticeable dependence of the ET process on the temperature in the combination films.

An outbreak of paragonimiosis in Zhengzhou city, China

An outbreak of paragonimiosis occurred in the city of Zhengzhou, Central China, in May 1995. Of seven exposed urban inhabitants, four were seropositive for Paragonimus and had clinical symptoms consistent with acute paragonimiosis. All of four cases treated were cured with praziquantel. The P. skrjabini adult worm was obtained from the rats experimentally infected with the crabs collected in the mountainous area where the urban inhabitants had got the infection. The outbreak was attributed to the intake of raw freshwater crabs while on tourist trips in a mountainous area.

The structure and function of murine factor V and its inactivation by protein C

Factor V (FV) is a central regulator of hemostasis, serving both as a critical cofactor for the prothrombinase activity of factor Xa and the target for proteolytic inactivation by the anticoagulant, activated protein C (APC). To examine the evolutionary conservation of FV procoagulant activity and functional inactivation by APC, we cloned and sequenced the coding region of murine FV cDNA and generated recombinant wild-type and mutant murine FV proteins. The murine FV cDNA encodes a 2,183-amino acid protein. Sequence comparison shows that the A1-A3 and C1-C2 domains of FV are highly conserved, demonstrating greater than 84% sequence identity between murine and human, and 60% overall amino acid identity among human, bovine, and murine FV sequences. In contrast, only 35% identity among all three species is observed for the poorly conserved B domain. The arginines at all thrombin cleavage sites and the R305 and R504 APC cleavage sites (corresponding to amino acid residues R306 and R506 in human FV) are invariant in all three species. Point mutants were generated to substitute glutamine at R305, R504, or both (R305/R504). Wild-type and all three mutant FV recombinant proteins show equivalent FV procoagulant activity. Single mutations at R305 or R504 result in partial resistance of FV to APC inactivation, whereas recombinant murine FV carrying both mutations (R305Q/R504Q) is nearly completely APC resistant. Thus, the structure and function of FV and its interaction with APC are highly conserved across mammalian species.

Changing pattern of delays in reporting AIDS diagnoses in Australia

To accurately monitor and predict the progress of the HIV/AIDS epidemic, it is important to adjust reported AIDS counts for reporting delays. This requires estimation of the reporting delay distribution. This paper aims to use a statistical model to identify the main factors influencing reporting delays in Australia and to adjust reported incidence data for these delays among cases of AIDS diagnosed from 1993 and reported before 30 June 1997. Reporting delays were found to vary significantly across states/territories. The influence of calendar time of diagnosis was also significant, with an overall trend toward longer delays over time. AIDS cases diagnosed in the fourth quarter of a year were reported significantly more quickly than those diagnosed in the first or third quarters. No significant differences were found due to sex, age and HIV exposure category, except people with haemophilia, in whom AIDS cases appeared to be reported more slowly. After adjusting for under-reporting and reporting delay, we found that the AIDS incidence in Australia was declining from about 1000 cases per year in 1994 to about 760 cases per year in 1996.

Natural killer-like nonspecific tumor cell lysis mediated by specific ligand-activated Valpha14 NKT cells

We have recently identified alpha-galactosylceramide (alpha-GalCer) as a specific ligand for an invariant Valpha14/Vbeta8.2 T cell receptor exclusively expressed on the majority of Valpha14 NKT cells, a novel subset of lymphocytes. Here, we report that alpha-GalCer selectively activates Valpha14 NKT cells resulting in prevention of tumor metastasis. The effector mechanisms of the ligand-activated Valpha14 NKT cells seem to be mediated by natural killer (NK)-like nonspecific cytotoxicity. Indeed, the cytotoxic index obtained by alpha-GalCer-activated Valpha14 NKT cells was reduced by the addition of cold target tumor cells or by treatment with concanamycin A, which inhibits activation and secretion of perforin, but not by mAbs against molecules involved in the NKT cell recognition and conventional cytotoxicity, such as CD1d, Vbeta8, NK1. 1, Ly49C, Fas, or Fas ligand. These results suggest that the ligand-activated Valpha14 NKT cells kill tumor cells directly through a CD1d/Valpha14 T cell receptor-independent, NK-like mechanism.

[Development of emission models for volatile organic compounds from indoor materials]

Volatile organic compounds (VOCs) emitted from indoor materials was a major cause of indoor air pollution. The characteristics of VOCs emission was an important part of research programs on indoor air quality. The technology of test chambers with exactly controllable conditions has been successfully used in studies of VOCs emissions. The technology could be used to model the chamber VOCs concentration level vs time profile C(t), which could in turn be used to estimate the sample emission rate vs time profile R(t). The emission models of VOCs from indoor materials were presented in this review. The principal of emission process, parameters and the applications of emission models were introduced. The application of diffusion model, dilution model and vapor pressure (VP) model were limited due to the existence of sink effect. Sink model is the most promising model at present.