Antibodies against Periodontal Microorganisms and Cognition in Older Adults

INTRODUCTION

Markers of poor oral health are associated with impaired cognition and higher risk of Alzheimer disease (AD) and thus may help predict AD.

OBJECTIVES

The aim of this study was to evaluate the cross-sectional association between empirically derived groups of 19 IgG antibodies against periodontal microorganisms and cognition in middle-aged and older adults.

METHODS

The study population consisted of participants of the third National Health and Nutrition Examination Survey (NHANES III) (1988 to 1994), who were 60 y and older, among whom cognition and IgG antibodies against 19 periodontal microorganisms were measured (N = 5,162).

RESULTS

In multivariable quantile regression analyses, the Orange-Red (Prevotella melaninogenica, Prevotella intermedia, Prevotella nigrescens, Porphyromonas gingivalis) and Yellow-Orange (Staphylococcus intermedius, Streptococcus oralis, Streptococcus mutans, Fusobacterium nucleatum, Peptostreptococcus micros, Capnocytophaga ochracea) cluster scores were negatively associated with cognition. A 1-unit higher cluster score for the Orange-Red cluster was associated on average with a lower cognitive score (β for 30th quantile = -0.2640; 95% confidence interval [CI], -0.3431 to -0.1848). Similarly, a 1-unit higher score for the Yellow-Orange cluster was associated with a lower cognitive score (β for 30th quantile = -0.2445; 95% CI, -0.3517 to -0.1372).

CONCLUSION

Groups of IgG antibodies against periodontal microorganisms were associated with lower cognition among free living adults 60 years and older, who were previously undiagnosed with cognitive impairment. Though poor oral health precedes the development of dementia and AD, oral health information is currently not used, to our knowledge, to predict dementia or AD risk. Combining our findings with current algorithms may improve risk prediction for dementia and AD.

KNOWLEDGE TRANSLATION STATEMENT

IgG antibodies against periodontal microorganisms were associated with lower cognition among adults 60 years and older previously undiagnosed with cognitive impairment. Periodontal disease may predict cognition among older adults.

[Effects of cinepazide maleate injection on blood pressure in patients with acute ischemic stroke and hypertension]

Objective: To investigate the blood pressure change in patients with acute ischemic stroke (AIS) and hypertension treated with cinepazide maleate injection. Methods: This was a subgroup analysis of post-marketing clinical confirmation study of cinepazide maleate injection for acute ischemic stroke: a randomized, double-blinded, multicenter, placebo-parallel controlled trial, which conducted in China from August 2016 to February 2019. Eligible patients fulfilled the inclusive criteria of acute anterior circulation ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) scores of 7-25. The primary endpoints were mean blood pressure of AIS patients treated with cinepazide maleate or control, which were assessed during the treatment period (14 days), and the proportion of the patients with normal blood pressure was analyzed after the treatment period. Furthermore, a subgroup analysis was performed to investigate a possible effect of the history of hypertension on outcomes. Results: This analysis included 809 patients with hypertension. There was no significant difference in patients blood pressure and the proportion of patients with normal blood pressure (60.5% vs. 59.0%,P>0.05) between cinepazide maleate group and control group. Conclusion: Administration of cinepazide maleate injection does not affect the management of clinical blood pressure in patients with AIS.

[Epidemiology of chronic cough in China: current status and future perspective]

Chronic cough is one of the most common major complaints in medical outpatient. Chronic cough not only seriously affects quality of personal life, but also burdens public health. Large-scale and high-quality epidemiological study on chronic cough has not been carried out in China, and relevant reviews are also lacking. Therefore, based on the studies concerning epidemiology of chronic cough in China, we reviewed the prevalence, risk factors, etiology, quality of life and economic burden. In addition, future perspectives and reasonable suggestions for the development of epidemiology of chronic cough were also proposed.

[Chronic cough in China: progress and perspectives]

Great progress has been made in regard of mechanism, etiological diagnosis and treatment of chronic cough since the beginning of the 20th century, and Chinese guidelines of diagnosis, management of cough was developed. Moreover, Chinese experts also participated in the formulation of international cough guidelines. Through the promotion of the guidelines, the level of diagnosis and treatment of chronic cough has been significantly improved in China. In the future, we should strengthen the studies on the epidemiology of chronic cough, the central regulation of chronic cough, and the treatment of refractory chronic cough, and promote the cough guidelines in primary community hospitals.

The value of soluble suppression of tumorigenesis-2 (sST2) in the maintenance of hemodialysis patients with heart failure

BACKGROUND

Patients with end-stage renal disease are prone to develop heart failure (HF). The N-terminal pro-brain natriuretic peptide (NT-proBNP, BNP) is regarded as the gold standard for diagnosing HF. However, its prognostic sensitivity in patients with end-stage renal disease is sub-optimal. Soluble suppression of tumorigenesis-2 (sST2) has been well studied in HF but rarely in patients with maintenance hemodialysis (MHD). This study aimed to evaluate the value of sST2 in predicting HF in MHD patients.

METHODS

Twenty-three patients with New York Heart Association (NYHA) class III-IV were included in the HF group and 88 NYHA class I-II patients in the non-heart failure (NHF) group. sST2 and laboratory indexes were compared between the two groups.

RESULTS

The HF group, compared with the NHF group, presented with higher sST2, more advanced age, higher incidence of coronary heart disease (CHD), left ventricle end-diastolic diameter (LVEDD), and pulmonary artery pressure (PAP), and unchanged parathyroid hormone (iPTH). The HF group also had lower ejection fraction (EF), uric acid, inorganic phosphorus, 25-OH VitD3, and serum albumin. Multivariate logistic regression indicated that age, BNP, and sST2 were independent risk factors of HF in MHD patients. Spearman analysis defined that sST2 was positively correlated with PAP (r =0.283, p =0.003) and C-reactive protein (r =0.354, p <0.001); and negatively correlated with sex (r =-0.255, p =0.007), albumin (r =-0.366, p <0.001), uric acid (r =-0.213, p =0.025), 25-OH VitD3 (r =-0.216, p =0.04), calcium (r =-0.219, p =0.021), and inorganic phosphorus (r =-0.256, p =0.007). Receiver operating characteristic curve analysis determined a positive association between BNP and sST2 (r =0.373, p <0.001), with the area under the curve (AUC) of BNP being 0.822 (sensitivity: 0.783, specificity: 0.830) and the AUC of sST2 being 0.841 (sensitivity: 0.913, specificity: 0.761). The AUC of sST2 was 0.841, and the cut-value was 42.840 (sensitivity: 0.913, specificity: 0.761).

CONCLUSION

sST2 can predict HF in MHD patients and facilitate early diagnosis and prevention of HF in MHD patients. HIPPOKRATIA 2022, 26 (1):19-24.

Reduced long noncoding RNA PGM5-AS1 facilitated proliferation and invasion of colorectal cancer through sponging miR-100-5p

OBJECTIVE

We aimed at investigating the expression of Long non-coding RNA (LncRNA) PGM5-AS1 and its facilitating effects on proliferation and invasion of colorectal cancer by sponging miR-100-5p.

PATIENTS AND METHODS

qRT-PCR was performed to detect the expressions of PGM5-AS1 and SMAD4 in human colorectal cancer tissues and cells. CCK-8 assay was performed to evaluate the SW403 cells proliferation and transwell assay was performed to evaluate the SW403 cells migration. The correlation between miR-100-5p and PGM5-AS1 was detected by statistical analysis. Bioinformatics prediction and Luciferase assay were performed to explore the interaction and binding site of PGM5-AS1 and miR-100-5p, miR-100-5p and SMAD4, respectively.

RESULTS

We found that both PGM5-AS1 and SMAD4 were downregulated in human colorectal cancer tissues and cells. qRT-PCR and CCK-8 assay showed that PGM5-AS1 expression is associated with the proliferation of colorectal cancer cells. Transwell assay showed that PGM5-AS1 regulated the migration ability of colorectal cancer cells. The bioinformatics prediction and Luciferase assay demonstrated that by sponging miR-100-5p, PGM5-AS1 can serve as a molecular sponge to further regulate the expression of SMAD4.

CONCLUSIONS

In this study, we found that lncRNA-PGM5-AS1 was low expressed in human colorectal cancer cells, which could promote tumor proliferation, migration and invasion by serving as a molecular sponge and by modulating the inhibitory effect of miR-100-5p on tumor suppressor gene SMAD4.

[Menopausal symptoms and quality of life of hormone receptor positive breast cancer patients at different endocrine therapy time]

Objective: To explore the menopausal symptoms and quality of life of hormone receptor positive (HR+ ) breast cancer patients at different endocrine therapy time. Methods: The HR+ breast cancer patients who were pathologically confirmed from 2011 to 2017 in the Sichuan Cancer Hospital were divided into three groups according to endocrine therapy time (<12 months, 12~36 months, >36 months) and analyzed by a cross-sectional study. The Menopausal symptoms and quality of life of these patients were measured using the modified Kupperman scale and the functional assessment of cancer therapy-breast cancer (FACT-B) scale. The differences of menopausal symptoms among different time groups and drug groups were analyzed by Chi-square test. The differences of quality of life and the effects of menopausal symptoms on quality of life were tested by covariance and multiple linear regression analyses. Results: The average score of menopausal symptom of 167 patients was 14.5±7.6 and the prevalence rate was 87.4% (146/167). Among all of the menopausal symptoms, the prevalence rate of insomnia was the highest (73.7%, 123/167). Besides insomnia and excitement, hot flashes was more prevalent in selective estrogen receptor modulator (SERM) users (64.8%, 79/122) , while osteoarthritis was more prevalent in aromatase inhibitor (AI) users (62.2%, 28/45). The total score of FACT-B of Patients was 104.5±15.5, and the compliance rate was up to 89.8% (150/167). However, the condition of each dimension was different, the compliance rates of social/ family and functional dimension were lowest, which were 73.0% (122/167) and 50.9% (85/167), respectively. The menopausal symptoms of patients at different time groups were 15.0±1.3, 14.0±6.9, 14.5±7.4, respectively, and the total score of FACT-B of patients at different time groups were 102.7±17.8, 105.0±12.9, 105.6±16.7, respectively, without significant differences (both P>0.05). Multiple linear regression analysis showed that menopausal symptoms impaired the quality of life of SERM users during the endocrine therapeutic period. The standardized regression coefficients of three time groups were -0.67, -0.30, -0.50, respectively, with the lowest effect on 12~36 months group. Conclusion: HR+ breast cancer patients will have a poor function recovery and social/ family return, who need more attention. Menopausal symptoms are common problems during endocrine therapy, and active measures should be taken to improve patients' quality of life.

[Association of plasma leptin levels and soluble leptin receptor with breast cancer]

Objective: To explore the association between plasma leptin (LEP) levels, soluble leptin receptor(SLR), free leptin index and breast cancer. Methods: 245 new female cases of primary breast cancer confirmed by histopathology examination were sequentially recruited into the study. A total of 245 age-matched healthy women were enrolled as controls during the same period. A standardized questionnaire was used to collect the demographic information of the subjects. Blood samples were collected and the levels of LEP and SLR in plasma were measured by enzyme linked immunosorbent assay. The differences of LEP, SLR and FLI expression between control and cases group, as well as different breast cancer subtypes and TNM stages were compared using t-test and ANOVA after stratification by menopause status. Multivariate logistic regression was used to explore the contributions of the three indexes to the risk of breast cancer. Results: Females in both cases and control group were (50.7 ± 9.4) years old. The level of SLR and FLI (P(50)(P(25),P(75))) in premenopausal women were 18.4 (11.2, 28.7), 0.5 (0.4, 0.6) μg/L in case group and 27.7 (19.2, 43.4), 0.3 (0.3, 0.4) μg/L in control group (P<0.001). While the level of postmenopausal women in case group were 20.3 (12.8, 31.8), 0.5 (0.4, 0.6) μ g/L (P<0.001), and 30.1 (18.8, 40.5), 0.3 (0.3, 0.5) μg/L in control group (P<0.001), respectively. After adjustment for confounding factors and BMI, the relationship between FLI and breast cancer remained significant for both pre- and postmenopausal women while the association between SLR and breast cancer was significant only in premenopausal women. Compared with the lowest level of SLR, higer levels of SLR is associated with a reduced risk of breast cancer (premenopausal women, OR=0.10, 95% CI: 0.04-0.29, P(trend)<0.001). Compared with the lowest level of FLI, FLI at higher levels is associated with an increased risk of breast cancer (premenopausal women, OR=7.14, 95% CI: 2.86-17.83, P(trend)<0.001; postmenopausal women, OR=8.10, 95% CI: 2.85-22.98, P(trend)<0.001). No significant association between LEP and breast cancer or association between the three indexes and breast cancer subtypes and TNM stages was found (P>0.05). Conclusion: SLR may be a protective factor for breast cancer while FLI may increase the risk of breast cancer.

MiR-26a regulates vascular smooth muscle cell calcification in vitro through targeting CTGF

Vascular calcification is one of the most important factors for high morbidity and mortality from cardiovascular and cerebrovascular diseases. The aim of this study is to investigate the effect and mechanism of miR-26a on vascular smooth muscle cell calcification. First, the VSMCs were induced by β-glycerol phosphate (β-GP) for 7d and 14d, and Alizarin Red S staining was performed to examine the mineralized nodule change; then real time RT-PCR and western blotting were performed to explore the expression of miR-26a, CTGF, OPG, RANKL and ALP in un-induced and β-GP-induced VSMCs; next, the VSMCs were transfected with miR-26a mimics, and Alizarin Red S staining was performed to examine the mineralized nodule change; finally, real time RT-PCR and western blotting were performed to explore the expression of miR-26a, CTGF, OPG, RANKL and ALP in un-transfected and miR-26a mimics transfected VSMCs. After β-GP treatment, β-GP promoted clear mineralized nodule changes, and miR-26a and OPG expression were significantly decreased and CTGF, RANKL and ALP expression were increased in VSMCs. Overexpression of miR-26a inhibited VSMCs calcification induced by β-GP, and regulated the expression of CTGF, OPG, RANKL and ALP. Our findings suggested that up-regulation of miR-26a before β-GP treatment inhibits VSMCs calcification through targeting CTGF (Fig. 4, Ref. 18).

Reduction Levels and the Effects of High-Molecular-Weight Adiponectin via AMPK/eNOS in Chinese Type 2 Diabetes

Aim: This study was to investigate the change of high-molecula-weight (HMW) adiponectin (APN) isoform, the association between type 2 diabetes mellitus (T2DM) and HMW APN isoform, the variation of Disulfide-bond A oxidoreductase-like protein (DsbA-L), the effect of HMW APN isoform on AMP-dependent protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) in Chinese T2DM. Method: 169 patients aged at (48.7±9.4) years and 107 healthy control subjects aged at (42.6±7.8) years took part in this study. Anthropometric measures of the characters were assayed and different APN isoforms, DsbA-L, AMPK and eNOS levels were determined. Results: Ln(sRAGE) and Ln(Adiponectin) were significantly lower and significantly higher for the other characteristics in T2DM. Ln(Adiponectin) was negatively and significantly correlated with WHR, Ln(triglycerides), fasting plasma glucose, HbA1c (%) in control subjects and T2DM patients. Plasma and adipose tissue total APN and HMW APN were significantly reduced in newly diagnosed T2DM patients. DsbA-L was markedly down-regulated in diabetic adipose tissue. HMW APN caused significant decreases in AMPK and eNOS phosphorylation levels of human umbilical vein endothelial cells (HUVECs). Conclusions: Our results demonstrated that total APN levels was closely related to the risk of T2DM and HMW APN reduction was involved in the diabetic vascular AMPK/eNOS signal pathway. The findings will provide insight into novel therapeutic approaches for reducing the elevated cardiovascular risk associated with T2DM.

β-Arrestins promote podocyte injury by inhibition of autophagy in diabetic nephropathy

β-Arrestins are multifunctional proteins originally identified as negative adaptors of G protein-coupled receptors (GPCRs). Emerging evidence has also indicated that β-arrestins can activate signaling pathways independent of GPCR activation. This study was to elucidate the role of β-arrestins in diabetic nephropathy (DN) and hypothesized that β-arrestins contribute to diabetic renal injury by mediating podocyte autophagic process. We first found that both β-arrestin-1 and β-arrestin-2 were upregulated in the kidney from streptozotocin-induced diabetic mice, diabetic db/db mice and kidney biopsies from diabetic patients. We further revealed that either β-arrestin-1 or β-arrestin-2 deficiency (Arrb1^−/− or Arrb2^−/−) ameliorated renal injury in diabetic mice. In vitro, we observed that podocytes increased both β-arrestin-1 and β-arrestin-2 expression levels under hyperglycemia condition and further demonstrated that β-arrestin-1 and β-arrestin-2 shared common mechanisms to suppress podocyte autophagy by negative regulation of ATG12–ATG5 conjugation. Collectively, this study for the first time demonstrates that β-arrestin-1 and β-arrestin-2 mediate podocyte autophagic activity, indicating that β-arrestins are critical components of signal transduction pathways that link renal injury to reduce autophagy in DN. Modulation of these pathways may be an innovative therapeutic strategy for treating patients with DN.

Ultrasonic imaging of gunshot wounds in pig limb

We investigated wound tract extension of traumatic gunshot wounds in limb soft tissues as well as wound tract sonographic features and change-patterns when the limb position was changed. The experimental animals included 8 healthy crossbred pigs in the Chengdu plain region. Chinese Type 53 Carbine was used to establish the gunshot wound model of porcine soft tissues. Gunshot-injured zones in the soft tissues were dynamically observed at different time points using ultrasonic technology. Pathological examinations were performed for the corresponding regions for comparison and analysis. The internal echo of the wound tract was a pipe-like echo that changed over time. The wound tract extension changed with postural changes. The gas echo extended along the inside of the wound track, surrounding the fascia to further tissues. Ultrasonic imaging of gunshot wounds in pig soft tissues shows specific characteristics. The application of ultrasound technology may provide important imaging protection for gunshot wound debridement and postoperative unobstructed drainage, helping to improve the judgment and treatment of limb gunshot injuries.

Parity violation of electroweak force in phase transitions of single crystals of d- and L-alanine and valine

Three kinds of experiments have been designed in attempting to observe theparity violation of electroweak force at the phase transition of singlecrystals of D- and L-alanine and valine.(1) An obvious λ phasetransition at 270 ± 1 K was shown in the specific heat measurement ofalanine and valine enantiomers by differential scanning calorimetry. Thebiologically dominant L-enantiomer was found to have lower energy. (2)Magnetization of single crystals of D- and L-alanine and D-valine weremeasured as a function of temperature using the SQUID magnetometer. Thedifference of the mass susceptibility χ(ρ) ∼ T curve between theD-alanine and L-alanine is attributable to the variation of intramoleculargeometry of chirality density, which is related to the parity violationenergy shift of a chiral molecule and is a consequence of the short rangeof the weak interaction between the nuclei and electrons. (3) Laser Ramanspectra of D- and L-alanine at different low temperatures (100 K, 250 K,260 K, 270 K, 280 K and 290 K) showed that the second order Cα-Hdeformation modes at 2606 cm(-1), 2724 cm(-1) of D-alanine vanishedat 270 K but reappeared at 100 K. In the same method, L-alanine has nosuch phenomenon. An obvious decrease in the scattering intensity of themethyne group C(α)-H stretching mode at 2964 cm(-1) in D-alanineoccurs at the λ transition temperature. We present our experimentsinvolving the possible relevance of Z(0) force with Salam's putativephase transition in the origin of homochirality.

Generation of mammalian cell lines with gene knock-down for human MCHR2

Appetite regulating neuropeptide melanin-concentrating hormone (MCH) has been implicated in obesity. It functions through its two receptors MCHR1 and MCHR2. While MCH and MCHR1 have been studied more extensively, the function of MCHR2 remains largely unknown, due to the lack of suitable in vitro and in vivo models. To create an in vitro system of genetic knock-down of MCHR2 in mammalian cells, we constructed four small hairpin RNAs (shRNAs) against human MCHR2 in eukaryotic expression vector, and transfected the plasmids into CHO cells that stably express human MCHR2. Using the empty vector or a negative shRNA control plasmid, we show that MCHR2-shRNAs suppressed 45.8% - 66.4% of MCHR2 expression at both mRNA and protein levels. As the result, in cells carrying the MCHR2-shRNAs, binding of MCHR2 to MCH was decreased by 39.4% - 78.7% accompanied by a similar decrease in affinity of the receptor to ligand by 40.9% - 81.9%. These cells still respond to MCH treatment, but intracellular Ca2+ release as the downstream signaling event was also decreased by 114.8% - 822.4%. Together, this study generated a set of shRNAs and cell lines as valuable reagents for further study on MCHR2 functions. These results will ultimately help to advance our knowledge about appetite regulating neuropeptide receptors.

Notch3 cooperates with the EGFR pathway to modulate apoptosis through the induction of bim

Notch signaling is a highly conserved pathway important for normal embryonic development and cancer. We previously demonstrated a role for Notch3 in lung cancer pathogenesis. Notch3 inhibition resulted in tumor apoptosis and growth suppression. In vitro, these effects were enhanced when the epidermal growth factor receptor (EGFR) pathway was also inhibited, suggesting significant cross-talk between the two pathways. How Notch3 and epidermal growth factor receptor-mitogen-activated protein kinase (EGFR-MAPK) pathways cooperate in modulating apoptosis is not yet known. In this study, we provide evidence that Notch3 regulates Bim, a BH-3-only protein, via MAPK signaling. Furthermore, loss of Bim expression prevents tumor apoptosis induced by Notch3 inhibition. Using gamma-secretase inhibitor and erlotinib in a xenograft model, Bim induction and tumor inhibition were observed to be enhanced compared with either agent alone, consistent with our previous observation of significant synergism between Notch and EGFR-ras-MAPK signaling. Thus, our data support the hypothesis that Notch3 not only has a crucial role in lung cancer through regulating apoptosis, but also cooperates with the EGFR-MAPK pathway in modulating Bim.

Study on energy metabolism in perioperative infants

OBJECTIVES

To evaluate resting energy expenditure (REE) in surgical infants and define the effects of the degree of stress on its level.

SUBJECTS AND METHODS

Between June 1999 and June 2003 forty-five infants awaiting surgery (boys/girls: 32/13) from the Department of Pediatric Surgery were entered in the study. Indirect calorimetry was used to measure the REE of all the patients before operation and 1 - 7 days after operation. Clinical data were collected, including age, weight, height, diagnosis, operative method, site and duration, and first day postoperative C-reactive protein (CRP) levels.

RESULTS

The REE before operation did not differ significantly from the postoperative values (paired t-test, p > 0.05). The predicted REE was significantly higher than the measured REE even before and after the operation (p < 0.01). REE values in the first three postoperative days were lower in the mild stress group than in the severe surgical stress group.

CONCLUSIONS

REE variation among the patients is relatively large. Changes in REE may be related to the degree of stress. Predicted REE values may be not a good reflection of measured REE.

Formulation and characterization of poly (D,L-lactide-co-glycolide) nanoparticle containing vascular endothelial growth factor for gene delivery

OBJECTIVE

The stability, in vitro release, in vitro cell transfection efficiency and in vivo gene transfer of vascular endothelial growth factor (VEGF(165)) plasmid DNA-loaded poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles were investigated.

METHODS

DNA-loaded nanoparticles were prepared with PLGA bearing VEGF(165) plasmid DNA and characterized with respect to morphology, size and encapsulation efficiency. The gene transfer efficiency of nanoparticles was tested in vitro on the cultured myocardial cells. And then the suspension of VEGF-loaded nanoparticles (VEGF-NPs) was injected into myocardial tissues in vivo to observe the process of nanoparticles as vectors for gene transfer to cardiac myocytes and to detect its biological effect and evaluate angiogenesis.

RESULTS

The encapsulation efficiency of the VEGF-NPs was 58.06 +/- 2.8% and their diameter ranged 100-300 nm. VEGF gene could be successfully transfected into myocardial cells by nanoparticles, which significantly enhanced gene transfection efficiency. A great number of nanoparticles were seen in the myocardial cytoplasm and nucleus. Furthermore, the nanoparticles began to dissolve and degrade. There was a significant increase in the number of capillaries in the VEGF-NPs group when compared with the plasmid DNA group.

CONCLUSION

The PLGA nanoparticles are capable of DNA delivery to cardiac myocytes for treating ischaemic myocardium. The direct gene transfer of VEGF-NPs into ischaemic rabbit myocardium can improve cardiac function and increase the number of capillaries.

Inhibition of ceramide-redox signaling pathway blocks glomerular injury in hyperhomocysteinemic rats

Ceramide-activated NAD(P)H oxidase has been reported to participate in homocysteine (Hcys)-induced abnormal metabolism of the extracellular matrix (ECM) in rat glomerular mesangial cells. However, it remains unknown whether this ceramide-redox signaling pathway contributes to glomerular injury induced by hyperhomocysteinemia (hHcys) in vivo. The present study was designed to address this question, defining the role of ceramide and activated NAD(P)H oxidase in the development of hHcys-induced glomerular injury. Uninephrectomized Sprague-Dawley rats were fed a folate-free diet for 8 weeks to produce hHcys and the de novo ceramide synthesis inhibitor myriocin or the NAD(P)H oxidase inhibitor apocynin was administrated. Rats with folate-free diet significantly increased plasma Hcys levels, renal ceramide levels, and NAD(P)H oxidase activity accompanied by marked glomerular injury. Treatment of rats with myriocin significantly reduced ceramide levels and improved glomerular injury, as shown by decreased urinary albumin excretion and reduced glomerular damage index. ECM components changed towards to normal levels with decreased tissue inhibitor of metalloproteinase-1 and increased matrix metalloproteinase-1 activity. NAD(P)H oxidase activity and Rac GTPase activity were reduced by 69 and 66%, respectively. In rats treated with apocynin, similar beneficial effects in protecting glomeruli from hHcys-induced injury were observed. These results support the view that de novo ceramide production is involved in Hcys-induced NAD(P)H oxidase activity in the kidney of hHcys rats and indicate the important role of ceramide-mediated redox signaling in hHcys-induced glomerular injury in rats.

[Selection of high taxol content cell lines of Taxus yunnanensis Cheng et L. K. Fu]

OBJECTIVE

To select high taxol content cell lines of Taxus yunnanensis.

METHOD

Choosing different cell aggregates according to their color, texture, growth rate and secretion of colorful substances, culturing them separately, and further analyzing their growth rates and taxolcontents.

RESULT AND CONCLUSION

Cell lines with higher taxol contents could be obtained by careful selection; those with darker color, lower growth rate and higher ratio of dry cell weight vs. fresh cell weight usually has higher taxol contents.

Asbestos fiber burdens in lung tissues of Hong Kong Chinese with and without lung cancer

To investigate the asbestos exposure level in non-occupational population and its relation to lung cancer, pulmonary asbestos fiber counts were observed with a modified alkali digestion method, in lung tissues from 65 random surgically treated lung cancer patients (42 males and 23 females) and that obtained from 107 random autopsy cases who died of either accidental death or acute myocardial infarction (44 males and 63 females) during 1987-1988. The patients and cases were all Hong Kong Chinese with no definite history of occupational exposure to asbestos. The non-lung cancer cases (NLCC) were divided into three groups based on different age ranges: 10 approximately, 40 approximately and 70 approximately years. The results showed that the medians of uncoated fiber counts (0, 32 and 52 fibers per mg dry tissue [f/mgDT] in the different age groups, respectively) increased in an age-dependent manner (P<0.01). However, the medians of coated fiber (asbestos body) counts were all 0 f/mgDT, with no statistically significant difference among the groups, showing a very low level of asbestos body burden in NLCC. In each age group, no difference in those counts between males and females was observed (P>0.05). Moreover, those counts in male lung cancer cases (medians of 62.5 and 17.5 f/mgDT, respectively) were greater than that in the control (32.5 and 0 f/mgDT, respectively) (P<0.01, P<0.05, respectively), however, regarding the female groups there was no statistically significant difference from the control. The results suggest that there is an environmental exposure to asbestos in Hong Kong Chinese, the level of which is, however, generally not sufficient to induce asbestos body. Environmental asbestos exposure in Hong Kong males may be one of the carcinogenic factors leading to lung cancer.

Three membrane-proximal amino acids in the human parainfluenza type 2 (HPIV 2) F protein are critical for fusogenic activity

In this study, we investigated the role of the membrane-proximal region of the human parainfluenza virus type 2 (HPIV2) F protein by mutational analysis, including deletion, insertion, and substitution. Deletion or replacement of the entire 12 amino acid region (aa 474-485) of the HPIV2 F protein completely abolished its fusion activity when coexpressed with the HPIV2 HN protein. Deletion of groups of four of aa 478-485, single alanine, or other amino acid substitutions among aa 478-485 had minimal or limited effects on HPIV2 F/HN-induced cell fusion. However, a significant reduction in, or complete inhibition of, fusion activity was observed when aa 474-477 were deleted, or the N475, F476, or F477 residues were singly substituted with alanine. In addition, insertions of four amino acids at this region or deletion of eight or more amino acids significantly reduced F protein fusion activity. The oligomerization patterns and levels of cell surface expression of the mutant F proteins were compared to those of the wild-type HPIV2 F protein. The mutant HPIV2 F proteins defective in fusion were also found to be unable to initiate hemifusion, indicating that there is a specific requirement for three specific amino acids as well as the spacing in this region for initiating lipid mixing.

Prevalence and clinical significance of anti-phospholipid antibodies in multiple sclerosis: a study of 89 patients

The prevalence of serum anti-phospholipid antibodies (aPL) was evaluated in multiple sclerosis (MS) patients to search for a possible association with a distinct form of the disease. Anti-cardiolipin antibodies (Ab) (aCL) and anti-beta 2 glycoprotein I Ab (abeta2GPI) were measured together with antinuclear Ab (ANA), anti-double-stranded DNA Ab (anti-ds DNA) and anti-myelin Ab in 89 patients. Twenty-nine (32.6%) patients had serum aPL, 19xaCL (15 of the IgG and four of the IgM isotype), 14 abeta2GPI (two IgG and 12 IgM) (four of these patients had both Ab). Prevalence of aCL correlated with that of ANA, which were positive in 52 patients (P=0. 005) and with anti-myelin Ab detected in two patients (P=0.046) but not with that of anti-ds DNA (mostly of the IgM class) detected in 28% of case by ELISA. No correlation could be found between aPL and age, sex, duration of the disease from diagnosis, category of MS, clinical course, clinical symptoms, serum IgM levels nor atypical lesions by magnetic resonance imaging. Hence, aCL and abeta2GPI are neither rare in MS nor associated with a specific clinical form of the disease and they cannot be a diagnosis exclusion criteria.

Vaccination of domestic pig with recombinant paramyosin. against Schistosoma japonicum in China

Paramyosin (PM), a myosin-like protein is a major antigen on Schistosoma japonicum (Sj). We reported that passive transfer of a monoclonal IgE SjE18varepsilon.1 which recognizes PM of Sj (SJPM), partially protected mice from challenge infection. In the present study, we developed an experimental model system of schistosomiasis japonica with domestic pigs in China and used it for the evaluation of vaccination with recombinant SJPM (rSJPM). Sixteen-week-old pigs were successfully infected by dermal penetration of 120 cercariae of a domestic strain of Sj (50-60% worm recovery 11 weeks after challenge). The pigs vaccinated with 400 UV attenuated cercariae showed a reduction of worm recovery (53%, p<0.001). The experimental groups were immunized intradermally with rSJPM and alum or TiterMax and were partially protected against the challenge infection (32-35% reduction).

Chiral beta-particles interact differentially with enantiomers--theory to solve a long-existing debate

The crucial organic molecules associated with life are chiral. Beta irradiation on the causal origin for the great preference of biomolecules in life over their corresponding enantiomers has been extensively studied. The left helical beta electrons, with spin and momentum antiparallel, should propagate with different velocities in the two enantiomers. Much effort has been done to investigate possible mechanism of inducing asymmetry, using longitudinally polarized beta rays to decompose asymmetrically racemic mixtures of biomolecules, but the results were inconclusive and contradictory. In this paper we present our viewpoint that the direct inelastic scattering between polarized electrons and chiral molecules is the dominant one in producing the asymmetry of cross sections for both beta+ and beta- irradiation. The inelastic cross section sigma (0 --> n) is dependent on the dipole strength Dn, rotatory strength Rn of the molecule. According to the theoretical study, the asymmetry of cross section F is approximately 10(-6) and it depends on the sign of Rn+(L type). When Rn+ > 0, sigma D > sigma L, it favors L-amino acid surviving. When Rn+ < 0, sigma D < sigma L, it favours D-amino acid surviving. Our results show that helical electrons do distinguish between molecules of opposite chirality, and the disputation and suspicion about the controversial experimental results between Garay and Darge & Thiemann can be explained.

New wiggler beamlines at BSRF

A new multipole wiggler has been installed in the ring of the Beijing Electron Positron Collider (BEPC), and two new beamlines were extracted from it for experiments, including LIGA, microprobe fluorescence analysis, high-pressure diffraction and soft X-ray research. The beam profile and photon intensity were measured and compared with the calculated values. The main parameters and characteristics of the two beamlines are illustrated. Some experimental results are presented.

Intersubunit surfaces in G protein alpha beta gamma heterotrimers. Analysis by cross-linking and mutagenesis of beta gamma

Heterotrimeric guanine nucleotide binding proteins (G proteins) are made up of alpha, beta, and gamma subunits, the last two forming a very tight complex. Stimulation of cell surface receptors promotes dissociation of alpha from the beta gamma dimer, which, in turn, allows both components to interact with intracellular enzymes or ion channels and modulate their activity. At present, little is known about the conformation of the beta gamma dimer or about the areas of beta gamma that interact with alpha. Direct information on the orientation of protein surfaces can be obtained from the analysis of chemically cross-linked products. Previous work in this laboratory showed that 1,6-bismaleimidohexane, which reacts with cysteine residues, specifically cross-links alpha to beta and beta to gamma (Yi, F., Denker, B. M., and Neer, E. J. (1991) J. Biol. Chem. 266, 3900-3906). To identify the residues in beta and gamma involved in cross-linking to each other or to alpha, we have mutated the cysteines in beta 1, gamma 2, and gamma 3 and analyzed the mutated proteins by in vitro translation in a rabbit reticulocyte lysate. All the mutants were able to form beta gamma dimers that could interact with the alpha subunit. We found that 1,6-bismaleimidohexane can cross-link beta 1 to gamma 3 but not to gamma 2. The cross-link goes from Cys25 in beta 1 to Cys30 in gamma 3. This cysteine is absent from any of the other known gamma isoforms and therefore confers a distinctive property to gamma 3. The beta subunit in the beta 1 gamma 2 dimer can be cross-linked to an unidentified protein in the rabbit reticulocyte lysate, generating a product slightly larger than cross-linked beta 1 gamma 3. The beta subunit can also be cross-linked to alpha, giving rise to two products on SDS-polyacrylamide gel electrophoresis, both of which were previously shown to be formed by cross-linking beta to Cys215 in alpha o (Thomas, T. C., Schmidt, C. J., and Neer, E. J. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 10295-10299). Mutation of Cys204 in beta 1 abolished one of these two products, whereas mutation of Cys271 abolished the other. Because both alpha-beta cross-linked products are formed in approximately equal amounts, Cys204 and Cys271 in beta are equally accessible from Cys215 in alpha o. Our findings begin to define intersubunit surfaces, and they pose structural constraints upon any model of the beta gamma dimer.

The G protein gamma subunit. Requirements for dimerization with beta subunits

Guanine nucleotide-binding protein beta and gamma subunits form a tightly bound complex that can only be separated by denaturation. Assembly of beta and gamma subunits is a complicated process. The beta 1 and gamma 2 subunits can be synthesized in vitro in rabbit reticulocyte lysate and then assembled into dimers, but beta 1 cannot form beta gamma dimers when synthesized in a wheat germ extract. In contrast, gamma 2 translated in either system can dimerize with beta 1, suggesting that dimerization-competent gamma 2 can be synthesized without the aid of specific chaperonins or other cofactors. Dimerization-competent gamma 2 in solution forms an asymmetric particle with a Stokes radius of about 21 +/- 0.4 A (n = 4), s20,w of 0.9 S (range 0.8-1.0 S, n = 2), and frictional ratio of 1.57 (assuming no hydration). To define the part of gamma 2 that is needed for native beta gamma dimer formation, a series of N- and C-terminal truncations were generated, synthesized in vitro, and incubated with beta 1. Dimerization was assessed by stabilization of beta 1 to tryptic proteolysis. Truncation of up to 13 amino acids at the C terminus did not affect dimerization with beta 1, whereas removal of 27 amino acids prevented it. Therefore, a region between residues 45 and 59 of gamma 2 is important for dimerization. Truncation of 15 amino acids from the N terminus greatly diminished the formation of beta gamma dimers, while removal of 25 amino acids entirely blocked it. Thus, another region important for forming native beta gamma is near the N terminus. Extension of the N terminus by 12 amino acids that include the influenza virus hemagglutinin epitope did not prevent beta gamma dimerization. Furthermore, in intact 35S-labeled COS cells, epitope-tagged gamma 2 coimmunoprecipitates with beta and alpha subunits. The N-terminal epitope tag must lie at the surface of the heterotrimer since it prevents neither heterotrimer formation nor access of the antibody.

G protein beta gamma subunit: physical and chemical characterization

The beta gamma subunits of heterotrimeric G proteins play a central role in regulating the function of the G protein alpha subunits and in modulating the activity of several enzymes and ion channels. We have used the signature tryptic cleavage pattern of native beta gamma from bovine brain as a starting point for our analysis of its physical and chemical properties. Digestion of bovine brain beta gamma with trypsin yields only 2 beta-derived fragments, with relative mobilities on SDS-PAGE of 14 kDa (amino terminal) and 27 kDa (carboxyl terminal), despite the presence of 32 potential tryptic cleavage sites in the beta 1 subunit. Trypsin-cleaved beta gamma remains in a complex that has the same apparent sedimentation coefficient as intact beta gamma, and retains its ability to associate functionally with the alpha o subunit. Comparison of the incorporation of [14C]iodoacetamide into reduced denatured beta and unreduced denatured beta showed that there are no disulfide bonds in the molecule to hold the complex together. The brain beta and gamma subunits can be cross-linked by 1,6-bis(maleimido)hexane to form a 46-kDa product on SDS-PAGE, and trypsin cleavage of cross-linked beta gamma shows that gamma is cross-linked to the 14-kDa amino-terminal fragment of the beta subunit. On the basis of its primary sequence, the beta subunit is predicted to form a repetitive structure encompassing the 27-kDa fragment and part of the 14-kDa fragment. Analysis of the thermal denaturation of trypsin-cleaved beta gamma supports this prediction and confirms that both fragments retain stable tertiary structures following tryptic cleavage.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural and functional studies of cross-linked Go protein subunits

The guanine nucleotide binding proteins (G proteins) that couple hormone and other receptors to a variety of intracellular effector enzymes and ion channels are heterotrimers of alpha, beta, and gamma subunits. One way to study the interfaces between subunits is to analyze the consequences of chemically cross-linking them. We have used 1,6-bismaleimidohexane (BMH), a homobifunctional cross-linking reagent that reacts with sulfhydryl groups, to cross-link alpha to beta subunits of Go and Gi-1. Two cross-linked products are formed from each G protein with apparent molecular masses of 140 and 122 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both bands formed from Go reacted with anti-alpha o and anti-beta antibody. The mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis is anomalous since the undenatured, cross-linked proteins have the same Stokes radius as the native, uncross-linked alpha beta gamma heterotrimer. Therefore, each cross-linked product contains one alpha and one beta subunit. Activation of Go by guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) does not prevent cross-linking of alpha to beta gamma, consistent with an equilibrium between associated and dissociated subunits even in the presence of GTP gamma S. The same cross-linked products of Go are formed in brain membranes reacted with BMH as are formed in solution, indicating that the residues cross-linked by BMH in the pure protein are accessible when Go is membrane bound. Analysis of tryptic peptides formed from the cross-linked products indicates that the alpha subunit is cross-linked to the 26-kDa carboxyl-terminal portion of the beta subunit. The cross-linked G protein is functional, and its alpha subunit can change conformation upon binding GTP gamma S. GTP gamma S stabilizes alpha o to digestion by trypsin (Winslow, J.W., Van Amsterdam, J.R., and Neer, E.J. (1986) J. Biol. Chem. 261, 7571-7579) and also stabilizes the alpha subunit in the cross-linked product. Cross-linked G o can be ADP-ribosylated by pertussis toxin. This ADP-ribosylation is inhibited by GTP gamma S with a concentration dependence that is indistinguishable from that of the control, uncross-linked G o. These two kinds of experiments indicate that alpha o is able to change its conformation even though it cannot separate completely from beta gamma. Thus, although dissociation of the subunits accompanies activation of G o in solution, it is not obligatory for a conformational change to occur in the alpha subunit.