Clinical outcomes of children with COVID-19 infection in a low-risk centre in Malaysia

INTRODUCTION

According to WHO, long-COVID or post- COVID-19 condition is defined as the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation. A systematic review and meta-analyses published in 2022, which mainly focus on the Western population, revealed that the prevalence of long COVID was 25.24%. Literature regarding long-COVID in children in Asia was scarce. The objectives of our study were to assess the long-term effect of COVID-19 infection in children and its correlation to their acute COVID- 19 infection.

MATERIALS AND METHODS

This study was conducted in Hospital Kepala Batas (HKB), a district hospital in Penang State, Malaysia, which was the designated regional COVID hospital during the pandemic. It was a retrospective observational study, where children who were admitted from November 2020 to March 2021, and attended follow-up clinics from Jan 2021 to May 2021, were recruited.

RESULTS

This study comprised 90 subjects, from 3 months old to 12 years old, mean of 6.5 years old. When comparing asymptomatic and symptomatic children, children with comorbidities were more likely to be symptomatic with a pvalue of 0.045 using the Pearson Chi-square test. All our patients' symptoms resolved upon discharge. During followup at 2-4 months after COVID-19 infection, all children were reported as back to their usual selves. Fifteen patients had recurrent symptoms. Most of their symptoms pointed towards an acute infection. One patient had two episodes of illness, while the rest had one. The most common symptoms were cough, fever and runny nose. The average duration of illness of these 16 episodes was 4.5 days with a standard deviation of 2.48. None of these symptoms lasted more than seven days. None of them required hospital admission. None of them had recurrent COVID-19 infections. Tweleve out of 72 children who had been going to school stopped physical school after COVID-19 infection. Our findings differed from other studies. These could be due to the limitations that we faced.

CONCLUSION

Most children who contracted COVID-19 infection recovered fully after acute infection, and most of them recovered fully without long-term sequelae.

[Research progress on autologous vascularized graft bone implant repair for maxillofacial bone defect]

Maxillofacial bone defect can seriously affect the patient's appearance, mastication, deglutition and speech function. At present, autologous bone grafting combined with implant repair is an effective method for reconstruction of maxillofacial bone defects. Due to the differences in density, nutrition, immunity and other aspects of bone graft at different donor sites, there may be a potential impact on implant repair. In this paper, the biological characteristics of vascularized autologous bone used in maxillofacial bone defect repair were reviewed, and the risk factors of implantation on the bone graft were discussed. It provides support for clinicians in the selection of bone graft donor site and the design of prosthesis.

[MicroRNA-23a knockdown attenuates angiotensin Ⅱ induced hypertrophy in rat H9c2 cells via activating PTEN and AMPK pathway]

Objective: To investigate if microRNA (miR) -23a knockdown could attenuate angiotensin Ⅱ(AngⅡ) induced cardiac hypertrophy by activating phosphatase and tensin homolog deleted on chromosome ten(PTEN) and AMP-activated protein kinase(AMPK) pathway. Methods: Rat H9c2 cells were cultured in DMEM high glucose medium and put in 5% CO(2) incubator at 37 ℃(normal group). After 48 hours of culture, H9c2 cells were stimulated with 10 nmol/L AngⅡ to establish cell hypertrophy model (AngⅡgroup). The H9c2 cells were inoculated in a 6-well cell culture plate and cultured in an incubator at 37 ℃. When the confluence degree of cell growth was about 70%, the cells were transfected with different reagents, and 24 hours after transfection, 10 nmol/L AngⅡ was used to interfere with the cells. The H9c2 cells were divided into different groups according to the reagents, namely AngⅡ+anti-miR group(transfected with miR-23a inhibitor), Ang Ⅱ+NC group(transfected with miR-23a inhibitor negative control), Ang Ⅱ+anti-miR+si-PTEN group(cotransfected with miR-23a inhibitor and PTEN small interference RNA(siRNA)), and AngⅡ+anti-miR+si-NC group(cotransfected with miR-23a inhibitor and PTEN siRNA negative control). The surface area of single cell was measured by Image J software.The mRNA expression levels of α-actin 1 (ACTA1) and β-myosin heavy chain (β-MHC) and miR-23a were detected by quantitative real-time PCR(qRT-PCR). The expression levels of PTEN and AMPK signal pathway related proteins were detected by Western blot. In order to verify whether miR-23a targets PTEN gene, double luciferase reporter gene experiment was performed. The luciferase reporter gene vector recombinant plasmids of wild type pGL-WT-PTEN and mutant pGL-MUT-PTEN were constructed and prepared after normal sequencing. H9c2 cells was inoculated into 24-well cell culture plate and cultured overnight in 37 ℃ incubator. The cells were co-transfected with miR-23a mimic or miR-23a mimic negative control and wild type or mutant reporter gene recombinant plasmid. Forty-eight hours after transfection, firefly luciferase activity and sea kidney luciferase activity were measured, and the ratio of them was recorded as relative luciferase activity. Results: Compared with the normal group, the cell surface area, the mRNA expression levels of ACTA1, β-MHC and miR-23a were significantly higher, while the protein expression levels of PTEN and p-AMPK were significantly lower in the Ang Ⅱ group(all P<0.05). The results of double luciferase reporter gene assay showed that the relative luciferase activity of cells co-transfected with miR-23a mimic and wild-type reporter gene recombinant plasmid was lower than that of miR-23a mimic negative control (P<0.05), and PTEN served as the target gene of miR-23a. In AngⅡ+anti-miR group the mRNA expression levels of miR-23a, ACTA1 and β-MHC were lower, and the cell surface area was smaller, while the protein expression levels of PTEN and p-AMPK were higher than that in AngⅡ group and AngⅡ+NC group(all P<0.05). Compared with AngⅡ+anti-miR group, the cell surface area was bigger, the expression of ACTA1 and β-MHC mRNA was up-regulated, and the protein expression levels of PTEN and p-AMPK were down-regulated in Ang Ⅱ+anti-miR+si-PTEN group(all P<0.05). Conclusion: Inhibition of miR-23a can attenuate Ang Ⅱ-induced hypertrophy in H9c2 cells through targeting PTEN and activating AMPK signaling pathway.

Association between iodine intake and thyroid autoantibodies: a cross-sectional study of 7073 early pregnant women in an iodine-adequate region

PURPOSE

The association between iodine intake and thyroid autoimmunity has been debated, especially in pregnant women. This study aimed to investigate thyroid autoantibodies and their association with iodine intake and hypothyroidism in early pregnancy.

METHODS

7073 early pregnant women from an iodine-sufficient region participated in this study. Urinary iodine concentrations (UICs) were measured using an ammonium persulfate method. Serum thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), thyroid-stimulating hormone (TSH), free thyroxine (FT4), and Tg were determined using an electrochemiluminescence immunoassay.

RESULTS

Iodine deficiency (UIC < 100 μg/L) was associated with higher risks of TPOAb positivity [adjusted odds ratio (aOR) = 1.64, 95% confidence interval [CI] (1.29-2.08)] and TgAb positivity [aOR = 1.44, 95% CI (1.16-1.80)]. Women with isolated TPOAb positivity, isolated TgAb positivity, or both TPOAb and TgAb positivity had a 14.64-fold, 7.83-fold, and 44.69-fold increased risk of overt hypothyroidism, and a 4.36-fold, 2.86-fold, and 6.26-fold increased risk of subclinical hypothyroidism, respectively. Moreover, the risks of overt and subclinical hypothyroidism in women with a high TPOAb titer were 16.99 and 4.80 times that in TPOAb-negative women, respectively. The risk of overt hypothyroidism in women with a high TgAb titer was 6.97 times that in TgAb-negative women.

CONCLUSIONS

Our work demonstrates that iodine deficiency during early pregnancy is an independent risk factor for both TPOAb positivity and TgAb positivity. Furthermore, positivity for both autoantibodies and a high thyroid autoantibody titer are associated with significantly higher risks of overt and subclinical hypothyroidism.

The impact of isolated maternal hypothyroxinemia during the first and second trimester of gestation on pregnancy outcomes: an intervention and prospective cohort study in China

OBJECTIVES

To explore the effect of isolated maternal hypothyroxinemia (IMH) during the first and second trimester of gestation on pregnancy outcomes. To explore whether levothyroxine (L-T4) treatment of women who had IMH identified in the first trimester improves pregnancy outcomes.

METHODS

Women in the early pregnancy in the iodine-sufficient area (n = 3398) were recruited to this prospective cohort study (ChiCTR-TRC-12002326). Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and thyroid peroxidase antibody (TPOAb) were detected. Women with IMH before 12 weeks chose to receive L-T4 or remain untreated. The L-T4 dose was adjusted to attain a normal FT4 and TSH level. Pregnancy outcomes were evaluated during follow-up.

RESULTS

IMH in the first trimester was not associated with increased risk of adverse pregnancy outcome compared with controls. The incidence of macrosomia (p = 0.022) and gestational hypertension (p = 0.018) was significantly higher in IMH identified in the second trimester of gestation compared with controls. IMH identified in the second trimester of gestation was a risk factor for macrosomia [adjusted odds ratio (aOR) 1.942, 95% CI 1.076-3.503, p = 0.027] and gestational hypertension (aOR 4.203, 95% CI 1.611-10.968, p < 0.01), when body mass index in the early pregnancy was < 25 kg/m².

CONCLUSIONS

IMH in the first trimester did not increase the risk of adverse outcomes irrespective of whether women received L-T4 treatment. However, IMH identified in the second trimester was associated with increased risk of adverse pregnancy outcome. The results suggest that thyroid function follow-up during the second trimester is necessary, even if thyroid function is normal during the first trimester.

Genetic variant spectrum in 265 Chinese patients with hemophagocytic lymphohistiocytosis: Molecular analyses of PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening hyperinflammatory disease. This study aimed to investigate the frequencies and distributions of inherited variants in PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP genes in Chinese patients with HLH. A total of 265 patients diagnosed with HLH from January, 2010 to December, 2016 were recruited and analyzed for the 6 genes. Genetic variants were observed in 87 (32.83%) patients. 36 (13.58%) exhibited variants in UNC13D, 18 (6.79%) exhibited PRF1 variants, 10 (3.77%) had variants in XIAP, 9 (3.40%) exhibited variants in STXBP2, 6 (2.26%) carried variants in SH2D1A, 1 (0.38%) had STX11 variant, and 7 (2.64%) exhibited digenic variants. Monoallelic variants were the most common, which accounted for 49.43% of all cases with variants. All variants were confirmed to be germline-derived. The present study describes a distinct variant spectrum in Chinese patients with HLH, whereby UNC13D is the most frequently mutated gene with missense variants that are the most common molecular defects. The variant profile of Chinese HLH patients is quite different from that of Western cohorts but similar to that of Korean patients, yet showing its own uniqueness. This racial difference shows the role of genetic background in the occurrence of HLH.

Eradication of hepatitis C virus profoundly prolongs survival in hepatocellular carcinoma patients receiving transarterial chemoembolization

Adjuvant pegylated interferon plus ribavirin treatment (PegIFN/RBV) reduces recurrence and prolongs survival in early stage hepatocellular carcinoma (HCC) patients with chronic hepatitis C (CHC) infection receiving resection or ablation. However, the impact of antiviral therapy in intermediate and advanced stage of CHC-HCC patients is uncertain. This study aimed to investigate the impact PegIFN/RBV treatment on recurrence-free interval and survival in patients with HCC receiving transarterial chemoembolization (TACE). From 2010 to 2013, 274 CHC patients from a 1073 patient-based cohort composed of freshly diagnosed HCC and receiving TACE treatment the Chang Gung Memorial Hospital, Linkou Medical Center were recruited. Propensity score matching (PSM) (age, gender, AST to Platelet Ratio Index (APRI), tumour size, tumour number and Child-Turcotte-Pugh score) with the ratio 1:2 for patients with and without PegIFN/RBV treatment was performed. Statistics were performed with SPSS V.20 (IBM, USA). After matching, 153 patients were analysed and 27 patients (17.6%) achieved sustained virologic response (SVR). The 2-year cumulative overall survival rate and recurrence-free survival rate among patients with SVR, non-SVR, and untreated were 85.2% vs 58.3% vs 69.6% (P=.001) and 73.3% vs 53.8% vs 58.5% (P=.013). By Cox regression analysis, non-SVR, untreated, increase CTP score and nonresponder to TACE were independent factors related to mortality. The SVR achieved by PegIFN/RBV treatment markedly improves survival and reduces tumour recurrence in CHC-HCC patients receiving TACE treatment after complete response.

Expression and distribution of SP and its NK1 receptor in the brain-gut axis in neonatal maternally separated rat model with visceral hypersensitivity

Neurokinin-1 receptor (NK1R) is a high affinity Substance P (SP) receptor and plays a key role in visceral hypersensitivity in irritable bowel syndrome (IBS). Early life stress is a significant risk factor in IBS. The aim of the present study was to investigate the influence of neonatal maternal separation on the expression and distribution of SP and its receptor along the brain-gut axis in a neonatal maternally separated rat model with visceral hypersensitivity. Male neonatal Sprague-Dawley rats, 2-21-day old, were randomly distributed into maternal separation groups of 3 h daily maternal separation (MS) or non-handling (NH). These rats underwent colorectal balloon distention (CRD) upon reaching adulthood. Immunofluorescence was used to examine the distal colon, lumbosacral spinal cord, and the brainstem to semi-quantitatively determine SP and NK1R expression before and after CRD. The following features were assessed: percentage SP-positive area in colonic muscle layer, the number of NK1R-positive myenteric plexus, SP-positive area and NK1-positivity score in the dorsal horn and the brainstem. Neither of these was altered in the MS and NH groups before or after CRD. These results suggest that the SP system might play little role in the development of visceral hyperalgesia in the neonatal maternal separation rat model.

Change in serum TSH levels within the reference range was associated with variation of future blood pressure: a 5-year follow-up study

Controversy exists on the relationship between serum thyrotropin (TSH) and blood pressure, and only a few prospective studies are available up to now. The study aimed to investigate the association between serum TSH within the reference range and blood pressure through a 5-year follow-up study. A total of 623 subjects with normal TSH were followed up for 5 years, including the measurement of demographic data, blood pressure, height, weight and serum TSH. Finally, 531 subjects were included in this prospective study. Body mass index (BMI), prevalence of hypertension, and systolic and diastolic blood pressure were all higher at follow-up than at baseline. Adjusted for age, gender, smoking status, BMI and homoeostasis model assessment of insulin resistance (HOMA-IR) at baseline, multiple linear regression analyses found no relationship between serum TSH at baseline and levels of blood pressure at follow-up, but the changes in serum TSH levels during follow-up was positively associated with the changes in systolic blood pressure (B=2.134, P<0.05), which became more significant in women but not significant in men. The change of systolic blood pressure in group of TSH increase >0.5 mIU l^-1 was significantly higher than in group of TSH decrease >0.5 mIU l^-1 within reference, after adjusting for age, gender, smoking status, BMI and HOMA-IR at baseline. This result became more significant in women, but no statistical significance was observed in men. Co-variation with serum TSH levels and blood pressure was observed during 5-year follow-up among people with normal TSH.

Lipid-mediated protein functionalization of electrospun polycaprolactone fibers

In this study, electrospun polycaprolactone (PCL) fibers are plasma-treated and chemically conjugated with cholesteryl succinyl silane (CSS). In addition to Raman spectroscopy, an immobilization study of DiO as a fluorescent probe of lipid membranes provides evidence supporting the CSS coating of plasma-treated PCL fibers. Further, anti-CD20 antibodies are used as a model protein to evaluate the potential of lipid-mediated protein immobilization as a mechanism to functionalize the CSS-PCL fiber scaffolds. Upon anti-CD20 functionalization, the CSS-PCL fiber scaffolds capture Granta-22 cells 2.4 times more than the PCL control does, although the two fiber scaffolds immobilize a comparable amount of anti-CD20. Taken together, results from the present study demonstrate that the CSS coating and CSS-mediated antibody immobilization offers an appealing strategy to functionalize electrospun synthetic polymer fibers and confer cell-specific functions on the fiber scaffolds, which can be mechanically robust but often lack biological functions.

Correlation of post-stroke fatigue with glucose, homocysteine and functional disability

BACKGROUND

Our aim was to clarify the correlation between fatigue during the acute stage of stroke with serum glucose and homocysteine (Hcy) levels and functional disability.

MATERIALS AND METHODS

A case group of 214 patients and a control group of 214 subjects were recruited during the same period. The serum glucose, Hcy, blood lipid and fibrinogen (FIB) levels of patients were determined. Fatigue was assessed using the Fatigue Severity Scale (FSS). Patients with an FSS score ≥4 points were defined as having fatigue. Stroke severity and the level of functional disability were assessed with the National Institutes of Health Stroke Scale (NIHSS) and the Barthel-20 Index (BI-20), respectively.

RESULTS

The incidence of fatigue in the case group was higher than that in the control group (P < 0.001). Within the case group, the fatigue group showed higher serum levels of glucose and Hcy, and a lower BI-20 score compared to the non-fatigue group (P < 0.001). Age, gender, chronic disease history, the NIHSS score and the serum blood lipid and FIB levels were not significantly different between the two groups. In the fatigue group, the serum glucose and Hcy levels showed a positive effect and the BI-20 score showed a negative effect on the FSS score (P < 0.01). Age, gender, chronic disease history, the NIHSS score and the serum blood lipid and FIB levels did not significantly affect the FSS score.

CONCLUSIONS

The serum glucose and Hcy levels and functional disability are closely related to fatigue during the acute stage of ischaemic stroke.

Defective expression of regulatory B cells in iodine-induced autoimmune thyroiditis in non-obese diabetic H-2(h4) mice

INTRODUCTION

The ability of B cells to negatively regulate cellular immune responses and inflammation has been described. The regulatory B (Breg) cells with the unique CD1d(hi)CD5(+)CD19(+) phenotype and the capacity to produce IL-10 are potent negative regulators of inflammation and autoimmunity in several in vivo mouse models of autoimmune disease.

AIM

To investigate whether Breg cell deficiency participates in autoimmune thyroiditis (AIT) in an animal model.

MATERIALS AND METHODS

Non-obese diabetic (NOD).H-2(h4) mice at 4 weeks of age were randomly divided into control and iodine-treated groups; the iodine-treated group received sterile water containing 0.005 % NaI for 10 or 20 weeks. The percentage of CD1d(hi)CD5(+)CD19(+) Bregs, CD4(+)CD25(+)FoxP3(+) regulatory T cells (Treg) and CD4(+)IL17(+) T helper 17 cells (Th17) in splenic mononuclear cells was detected by multicolor flow cytometry. The expression of IL-10 mRNA and TGF-β mRNA in splenocytes was measured by real-time RT-PCR.

RESULTS

NOD.H-2(h4) mice spontaneously develop anti-thyroglobulin autoantibodies and intrathyroidal lymphocyte infiltration when supplied with iodine in drinking water. Mice with AIT had a decreased CD1d(hi)CD5(+)CD19(+) Breg subset and reduced IL-10 mRNA expression in splenocytes compared with controls (p < 0.05) and maintained relatively low levels during the development of thyroiditis. The proportion of Breg cells was negatively correlated with the proportion of Th17 cells, but positively correlated with CD4(+)CD25(+)FoxP3(+) Treg cells in splenocytes (All p < 0.05).

CONCLUSIONS

The defective expression of Breg cells combined with impaired Treg cells and enhanced Th17 cells might play an important role in the development of iodine-induced AIT in NOD.H-2(h4) mice.

Developmental hypothyroxinaemia induced by maternal mild iodine deficiency delays hippocampal axonal growth in the rat offspring

Iodine is essential for the biosynthesis of thyroid hormones, including triiodothyronine and thyroxine. Thyroid hormones are important for central nervous system development. Mild maternal iodine deficiency (ID)-induced hypothyroxinaemia causes neurological deficits and mental retardation of the foetus. However, the detailed mechanism underlying these deficits is still largely unknown. Given that the growth-associated protein of 43 kDa (GAP-43), semaphorin 3A (Sema3A) and the glycogen synthase kinase 3β (GSK3β)/collapsin response mediator protein 2 (CRMP2) pathway are essential for axonal development, we hypothesise that hippocampal axonal growth-related proteins may be impaired, which may contribute to hippocampal axonal growth delay in rat offspring exposed to maternal hypothyroxinaemia. To test this hypothesis, maternal hypothyroxinaemia models were established in Wistar rats using a mild ID diet. Besides a negative control group, two maternal hypothyroidism models were created with either a severe ID diet or methimazole in the water. Our results showed that maternal hypothyroxinaemia exposure delayed offspring axonal growth on gestational day 19, postnatal day (PN) 7, PN14 and PN21. Consistent with this, the mean intensity of hippocampal CRMP2 and Tau1 immunofluorescence axonal protein was reduced in the mild ID group. Moreover, maternal hypothyroxinaemia disrupted expressions of GAP-43 and Sema3A. Furthermore, the phosphorylation of GSK3β and CRMP2 was also affected in the treated offspring, implying a potential mechanism by which hypothyroxinaemia-exposure affects neurodevelopment. Taken together, our data support the hypothesis that maternal hypothyroxinaemia may impair axonal growth of the offspring.

Gold surface supported spherical liposome-gold nano-particle nano-composite for label free DNA sensing

Immobilization of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) liposome-gold nano-particle (DOPE-AuNP) nano-composite covalently on 3-mercaptopropionic acid (MPA) on gold surface is demonstrated for the first time for electrochemical label free DNA sensing. Spherical nature of the DOPE on the MPA monolayer is confirmed by the appearance of sigmoidal voltammetric profile, characteristic behavior of linear diffusion, for the MPA-DOPE in presence of [Fe(CN)(6)](3-/4-) and [Ru(NH(3))(6)](3+) redox probes. The DOPE liposome vesicle fusion is prevented by electroless deposition of AuNP on the hydrophilic amine head groups of the DOPE. Immobilization of single stranded DNA (ssDNA) is made via simple gold-thiol linkage for DNA hybridization sensing in the presence of [Fe(CN)(6)](3-/4-). The sensor discriminates the hybridized (complementary target hybridized), un-hybridized (non-complementary target hybridized) and single base mismatch target hybridized surfaces sensitively and selectively without signal amplification. The lowest target DNA concentration detected is 0.1×10(-12)M. Cyclic voltammetry (CV), electrochemical impedance (EIS), differential pulse voltammetry (DPV) and quartz crystal microbalance (QCM) techniques are used for DNA sensing on DOPE-AuNP nano-composite. Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS) and Ultraviolet-Visible (UV) spectroscopic techniques are used to understand the interactions between the DOPE, AuNP and ssDNA. The results indicate the presence of an intact and well defined spherical DOPE-AuNP nano-composite on the gold surface. The method could be applied for fabrication of the surface based liposome-AuNP-DNA composite for cell transfection studies at reduced reagents and costs.

Treatment with levothyroxine in pregnant rats with subclinical hypothyroidism improves cell migration in the developing brain of the progeny

AIM

This study aims to investigate whether maternal subclinical hypothyroidism (SCH) influences the developing brain, and the effect of treatment with levothyroxine (L-T4) in early maternal SCH on the progeny's developing brain.

MATERIALS AND METHODS

Seventy-five thyroidectomized female Wistar rats were divided randomly into groups of hypothyroidism (CH), SCH, SCH treated with L-T4 from embryonic day (E) 10, E13, and E17 till post-natal day 21. There were 15 sham operated controls.

RESULTS

Pups from SCH or CH group had significantly lower body weight than euthyroid group. Pups from E10, E13 or E17 groups had normal body weight compared to control pups at P3 and P7. The levels of TSH and total T4 (TT4) of all pups were normal. The mean latencies were longer in pups from CH, SCH, and E17 group than controls. The latencies from E10 and E13 pups were comparable to those from control pups. There were changes in the cytoarchitecture of the barrel cortex and of the hippocampus in CH, SCH, and E17 pups. The barrel cortex of E10 or E13 pups was similar to that of control pups. The distribution of bromodeoxyuridinelabeled cells was more widespread in CH, SCH, and E17 pups than in control, E10, and E13 progeny.

CONCLUSIONS

Maternal SCH disturbs learning and memory performances in pups, and affects cytoarchitecture and cell migration in the developing brain of the progeny. Treatment with L-T4 in early maternal SCH before E13 improves cell migration in the developing brain, as well as learning and memory function of the progeny.

Early levothyroxine treatment on maternal subclinical hypothyroidism improves spatial learning of offspring in rats

Maternal hypothyroidism has adverse effects on neural development in the offspring. The present study aimed to investigate whether maternal subclinical hypothyroidism impairs spatial learning in the offspring, as well as the efficacy and optimal time of levothyroxine (L-T(4)) treatment in pregnancy. Female adult Wistar rats were randomly divided into six groups (n = 10 per group): control, hypothyroid (H), subclinical hypothyroid (SCH) and SCH treated with L-T(4), starting from the tenth, thirteenth and seventeenth gestational day (GD10, GD13 and GD17), respectively, to restore normal thyroid hormone levels. Spatial learning was assessed on progenies by a water maze test, a field excitatory postsynaptic potential (fEPSP) recording, and an long-term potentiation induction assay. Protein levels of early growth response protein 1 (Egr1), activity-regulated cytoskeleton-associated protein (Arc), Ras-proximate-1 (Rap1), p-extracellular signal-regulated kinase (p-ERK) and brain-derived neurotrophic factor (BDNF) were determined by western blotting. Progenies from the SCH and H groups demonstrated significantly longer mean latency in the water maze test and a lower amplification percentage of the amplitude and slope of the fEPSPs compared to offspring of the control group. L-T(4) treatment for the GD10 and GD13 groups significantly shortened mean latency and increased the amplification percentage of the amplitude and slope of the fEPSPs of the progeny of rats with subclinical hypothyroidism. However, L-T(4) treatment for the GD17 group showed only minimal effects on spatial learning in the offspring. Progenies of SCH and H groups had lower levels of Egr1, Arc, p-ERK and BDNF but higher levels of Rap1 compared to those of the controls. L-T(4) treatment ameliorated these protein expression changes in the progeny of rats with subclinical hypothyroidism. Maternal subclinical hypothyroidism impaired spatial learning in the offspring; L-T(4) treatment in early pregnancy recovered this adverse effect, and the optimal time of treatment should start from early pregnancy (GD10 and GD13).

Riluzole protects against cardiac ischaemia and reperfusion damage via block of the persistent sodium current

BACKGROUND AND PURPOSE

Current strategies to ameliorate cardiac ischaemic and reperfusion damage, including block of the sodium-hydrogen exchanger, are therapeutically ineffective. Here we propose a different approach, block of the persistent sodium current (INaP).

EXPERIMENTAL APPROACH

Left ventricular pressure was measured as an index of functional deficit in isolated, Langendorff perfused, hearts from adult rats, subjected to 30 min global ischaemia and reperfusion with vehicle only (control) or riluzole (1-10 microM) in the perfusate. Cell shortening and intracellular Ca2+ concentrations [Ca2+](i) were measured in adult rat isolated myocytes subjected to hypoxia and re-oxygenation. The block of transient and persistent sodium currents by concentrations of riluzole between 0.01 and 100 microM were assessed in rat isolated myocytes using patch clamp techniques.

KEY RESULTS

In perfused hearts, riluzole produced a concentration-dependent cardioprotective action, with minor protection from 1 microM and produced rapid and almost complete recovery upon reperfusion from 3 and 10 microM. In isolated myocytes, riluzole at 3 and 10 microM greatly attenuated or prevented the hypoxia- and reperfusion-induced rise in [Ca2+](i) and the contractile deficit. In patch clamp experiments, riluzole blocked the persistent sodium current with an IC(50) of 2.7 microM, whereas the block of the transient sodium current was only apparent at concentrations above 30 microM.

CONCLUSIONS AND IMPLICATIONS

Riluzole preferentially blocked INaP and was protective in cardiac ischaemia and reperfusion. Thus block of the persistent sodium current would be a viable method of ameliorating cardiac ischaemic and reperfusion damage.

QTL analyses of seed weight during the development of soybean (Glycine max L. Merr.)

At harvest traits such as seed weight are the sum of development and responses to stresses over the growing season and particularly during the reproductive phase of growth. The aim here was to measure quantitative trait loci (QTL) underlying the seed weight from early development to drying post harvest. One hundred forty-three F(5) derived recombinant inbred lines (RILs) developed from the cross of soybean cultivars 'Charleston' and 'Dongnong 594' were used for the analysis of QTL underlying mean 100-seed weight at six different developmental stages. QTL x Environment interactions (QE) were analyzed by a mixed genetic mode based on 3 years' data. At an experiment-wise threshold of a=0.05 and by single-point analysis 94 QTL unaffected by QE underlay the mean seed weight at different developmental stages. Sixty-eight QTL affected by QE that also underlay mean seed weight were identified. From the 162 QTL 42 could be located on 12 linkage groups by composite interval mapping (LOD>2.0). The numbers, locations and types of the QTL and the genetic effects were different at each developmental stage. On linkage group C2 the distantly linked QTL swC2-1, swC2-2 and swC2-3 each affected mean seed weight throughout the different developmental stages. The DNA markers linked to the QTL possessed potential for use in marker-assisted selection for soybean seed size. The identification of QTL with genetic main effects and QE interaction effects suggested that such interactions might significantly alter seed weight during seed development.

A five-year follow-up study of goiter and thyroid nodules in three regions with different iodine intakes in China

OBJECTIVE

The association between iodine status and the prevalence of goiter and thyroid nodules has been well established but the extent to which different iodine intake levels influence the incidence of goiter and thyroid nodules is unclear. The aim of the study was to determine the incidence of goiter and thyroid nodules in 3 regions with different iodine intake levels: mildly deficient, more than adequate, and excessive.

DESIGN, PATIENTS AND MEASUREMENTS

Of the 3385 unselected subjects enrolled in 1999 in Panshan, Zhangwu, and Huanghua where median urinary iodine excretion (UIE) was 83.5 microg/l, 242.9 microg/l, and 650.9 microg/l, respectively, 2708 (80.0%) participated in the follow-up study in 2004. The examinations of thyroid ultrasonography, thyroid function, thyroid autoantibodies and UIE were performed at baseline and follow-up.

RESULTS

The cumulative incidence of diffuse goiter was 7.1%, 4.4%, and 6.9%, respectively, higher in Panshan and Huanghua than in Zhangwu (p=0.013 and p=0.015) and that of nodular goiter was 5.0%, 2.4%, and 0.8%, respectively, declining with increasing iodine intake levels (p<0.001). Mild iodine deficiency, chronic iodine excess as well as positive thyroid autoantibodies were associated with the occurrence of goiter [Logistic regression: odds ratio (OR)=1.83 (95% confidence interval (CI) 1.26-2.65), OR=1.46 (95% CI 1.01-2.11) and OR=1.68 (95% CI 1.14-2.48), respectively]. The cumulative incidence of single nodule was 4.0%, 5.7%, and 5.6%, respectively and that of multiple nodules was 0.4%, 1.2%, and 1.0%, respectively.

CONCLUSIONS

The relationship between iodine and the risk for the occurrence of diffuse goiter shows a U-shaped curve. Nodular goiters are more prevalent in iodine-deficient areas.

High iodine intake is a risk factor of post-partum thyroiditis: result of a survey from Shenyang, China

The aim of the present study is to obtain the epidemiological data on post-partum thyroiditis (PPT) firstly in Chinese women, and to tryto evaluate whether excessive intake of iodine in post-partum women imposes any danger of occurring PPT. Sixty hundred and ten pregnant women were involved in the cohort just before delivery. Four hundred and eighty-eight (80%) of them accepted taking part in follow-ups more than 6 months post-partum. A blood sample was taken from participants before delivery and every 3 months post-partum for testing of serum TSH, thyroid autoantibodies. Free T3 (FT3), free T4 (FT4) and TSH receptor antibody (TRAb) were detected if TSH was abnormal. The iodine nutrition was evaluated according to the mean level of the fasting urinary iodine excretions at different times during the studying period, and participants were subgrouped into 3 categories with low, adequate and high iodine intake. For those participants who had thyroid dysfunction within 6 months post-partum, the follow-up persisted for 1 yr. Of 488 pregnant women, PPT developed in 11.9% (58/488). Given overt and subclinical PPT, the prevalence was 7.17% (no.=35) and 4.71% (no.=23), respectively. There was a strong association between the presence of thyroid peroxidase antibody (TPOAb) at delivery and the risk of developing PPT [RR=6.76, 95% (CI) 4.42-10.34]. Overt cases had much higher titers of TPOAb than subclinical patients (all p<0.05). The median urinary iodine (MUI) of patients with PPT was significantly higher than that of healthy women (231.93 vs 199.88 microg/l p=0.00153). Both the prevalence of PPT and positive TPOAb rise with the increment of iodine intakes. Pregnant women with high iodine intake had more risk of developing PPT when compared with those with low iodine intake (RR=2.92, 95%CI 1.31-6.50). We concluded that positive TPOAb was of value for predicting the occurrence and severity of PPT, and a high iodine intake was a risk factor triggering PPT.

[Stability analysis of micropipette aspiration of cell by liquid drop modeling]

A generally realized phenomenon in the suction experiment of cells is that if the aspiration pressure is larger than a certain threshold, cell flows continuously into the pipette. The point of the threshold aspiration pressure at which the cell can still be held in a stable equilibrium is called the critical point of aspiration. Here we represent a theoretical analysis of the equilibrium behavior and stability of cell by liquid drop model. In the method of analysis, the areal change due to a small movement deltaL of the portion of the membrane in pipette is given to the first approximation. The threshold pressure and the critical point are shown as simple formulas of the model parameters and inner relative radius of pipette. The results derived from formulas are consistent with rigorous ones by numerical computation in the approximate range.

[The advance of experimental cell division biomechanics]

The advance of experimental cell division and proliferation in the field of cell biomechanics is presented in this paper. The emphasis is placed on the research in the mechanics mechanism of cleavage furrow and in the measurement of constricting force about cleavage furrow.

[The biomechanical model of cytokinesis in animal cells]

As the basis of cell proliferation, cytokinesis involves the division of the cytoplasm and the plasma membrane into two. In this paper a few models on the active deformation mechanism during cytokinesis process are presented. Discussions are made onvarious models, conclusions, differences between the numerical results and the corresponding experimental results.

Effects of prolactin on HLA-DR and CD40 expressions by human thyrocytes

OBJECTIVE

To study the effects of prolactin (PRL) on HLA-DR and CD40 expressions by human thyrocytes, and to investigate the possible mechanisms for PRL to affect the development of Graves' disease (GD).

METHODS

Thyrocytes in secondary culture, which were from GD thyroid glands and the tissues adjacent to the lesions of multinodular goiter and adenoma (control group), were treated respectively with ovine PRL (oPRL), interferon-gamma (IFN-gamma), interlukin-4 (IL-4) and oPRL plus IFN-gamma (10 U/ml) or IL-4 (5 ng/ml) for 7 days. HLA-DR and CD40 expressions on the thyrocytes were determined by immunofluorescent staining and flow cytometry.

RESULTS

oPRL (12.5 ng/ml-1000 ng/ml) had no significant direct effect on HLA-DR or CD40 expression. It did not significantly affect the stimulation of HLA-DR expressions on the two groups of thyrocyte treated with IFN-gamma or on GD thyrocytes treated with IL-4. oPRL could antagonize the stimulation of CD40 expressions by IFN-gamma and the inhibition by IL-4 on both groups of thyrocytes. The antagonizing effects were related to the concentrations of PRL. IFN-gamma-stimulated percentages of CD40+ thyrocytes and delta mean fluorescence intensity (dMF) in both thyrocyte sources were significantly reduced in the presence of 200 ng/ml oPRL (both GD and

CONTROL

P < 0.01 and P < 0.05, respectively;

CONTROL

P < 0.05) and 1000 ng/ml oPRL (GD: P < 0.01;

CONTROL

P < 0.05). oPRL caused significant increasing in IL-4-inhibited percentages of CD40+ cells from the two groups of thyrocytes at 12.5 ng/ml and 1000 ng/ml and dMF from GD thyrocytes at 1000 ng/ml (P < 0.05).

CONCLUSIONS

PRL can exert indirect effects on CD40 expressions on thyrocytes by antagonizing the modulatory actions of IFN-gamma and IL-4 with dose-related effects. This may be one important mechanism for PRL to affect the development of GD.

[An epidemiological survey of thyroid disorders in an area with high iodine content in water supply]

OBJECTIVE

To investigate the status of thyroid disorders among people aged 14 years and older residing in Huanghua County, an iodine excess intake area in north China.

METHODS

4,230 people were asked to fulfill the questionnaire and 1,074 among them aged (36.97 +/- 12.83) years were accepted to be samples for the test. All subjects who were taken as samples needed to fill the questionnaire on thyroid disorders in detail, accept physical and ultrasound examination. Their morning fasting urine were collected for measurement of iodide concentration, and their sera were measured for thyroid-stimulating hormone(TSH, the third generation), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb) and thyroglobulin (TG). If some people had abnormal TSH level, their free T4, free T3 and TSH receptor antibody(TRAb) were measured.

RESULTS

The median level of urinary iodide of the sample subjects was 614.61 micrograms/L. The prevalence of clinical and subclinical hyperthyroidism was 1.21% and 1.12% respectively; 92.3% of the clinical hyperthyroidism were of Graves' disease and 75% of the subjects with subclinical hypothyroidism were TRAb positive. The average incidence of clinical hyperthyroidism was not different between 2 periods before and after general iodinization of table salt in this area (1991-1995 and 1996-2000). The prevalence of clinical and subclinical hypothyroidism was 1.96% and 6.05% respectively. All the clinical patients were female, among them 85.71% were TPOAb and/or TGAb positive, while only 29.23% of the subclinical patients were TPOAb and/or TGAb positive. Positive TPOAb and TGAb were seen in 11.6% and 9.3% respectively of the sample subjects with an age-related increase. Positive thyroid autoantibody was more common in the female and those with abnormal TSH. The prevalence of thyroid cancer during the period of 1994-2000 was 91.58/100,000.

CONCLUSION

The high prevalence of hypothyroidism and thyroid cancer indicates that excessive iodine intake in this area is not safe.

[Comparative epidemiological study on thyroid cancer in areas with different iodine intakes]

OBJECTIVE

To investigate the status of thyroid cancer among people aged 14 and over residing in areas with different iodine intakes.

METHODS

In-door interviews on prevalence of thyroid cancer were conducted among 22 976 persons aged 14 and over residing in three rural communities in Panshan County, Liaoning Province, an iodine deficient area, Zhangwu County, Liaoning Province, an iodine sufficient area, and Huanghua County, Hebei Province, an iodine excessive area. Morning fasting urine, drinking water and table salt were collected from part of the interviewees to be tested.

RESULTS

The medians of urinary iodide were 103.2 microgram/L, 374.8 microgram/L and 614.6 microgram/L among the interviewees in Panshan, Zhangwu and Huanghua respectively. No patient with thyroid cancer was found in Panshan and Zhangwu, while 10 interviewees in Huanghua were suffering from thyroid papillary carcinoma. During the period of 1994 - 2000, the prevalence of thyroid cancer was 91.58/100 000, and the incidence was 13.12/100 000 per year in Huanghua.

CONCLUSION

The prevalence and incidence of thyroid cancer in iodine excessive area are much higher than those in the other two areas.

[Effect of iodine intake on thyroid diseases and intelligence among schoolchildren in rural areas]

OBJECTIVE

To understand the throid function and intelligence among the schoolchildren in three rural areas with different iodine intakes in China to probe the side-effect of excessive iodine intake on intelligence of schoolchildren.

METHODS

Chinese version of Raven's test was made among rural schoolchildren, 190 from Panshan County, Liaoning Province, a low iodine intake area with the median urinary iodine (MUI) of 99 microgram/L among its inhabitants, 236 from Zhangwu County, Liaoning Province, a moderate iodine intake area with the MUI of 338 microgram/L, and 313 from Huanghua County, Hebei Province, an excessive iodine intake area with the MUI of 631 microgram/L. Thyroid function, thyroid autoantibody (TAA), and MUI were determined among 116, 110 and 112 from the above-mentioned schoolchildren from these three areas respectively.

RESULTS

There was no significant difference among the prevalence rates of overt hyperthyroidism, subclinical hyperthyroidism and overt hypothyroidism in the areas of Panshan, Zhangwu and Huanghua. However, a significant difference was found among the prevalence rates of subclinical hypothyroidism in theses three areas (P = 0.001). The prevalence rates of subclinical hypothyroidism in Huanghua and Zhangwu were 4.76 and 3.37 times higher than that in Panshan (P = 0.001). TAA was negative among all of the schoolchildren with subclinical hypothyroidism except for one. No significant difference was found among the positive rates of thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) in these three areas. Serum thyroglobulin (TG) values in Huanghua were markedly higher than those in the other two areas (P = 0.015 7). Serum TG value in Zhangwu was higher than that in Panshan but with no significant difference. The IQ value of the schoolchildren in Huanghua was markedly higher than that in Zhangwu (P = 0.001 2). The IQ value of the schoolchildren in Panshan was lower than that in Huanghua and higher than that in Zhangwu but with no significant difference.

CONCLUSION

The increase of iodine intake may increase the risk of subclinical hypothyroidism among schoolchildren. In the area with excessive iodine intake, most of the subclicical hypothyroidism cases among schoolchildren are not of autoimmune origin. No obvious effect of excessive iodine intaue is found on mental development of schoolchildren.

[Effects of prolactin on in-vitro interactions between thyrocytes from patients with Graves' disease and autologous peripheral blood mononuclear cells]

OBJECTIVE

To study the effects of prolactin on interactions between Graves' disease (GD) thyrocytes and autologous peripheral blood mononuclear cells (PBMC) in coculture.

METHODS

Primary thyrocytes and autologous PBMC were cocultured at various levels of ovine prolactin (oPRL) in vitro. The activation and proliferation of PBMC as well as HLA-DR and CD(40) expressions on thyrocytes were determined by immunofluorescent staining and flow cytometry.

RESULTS

With PBMC in GD cocultures, oPRL caused significant increase in the percentage of CD(4)(+) CD(25)(+) cells at 200 microg/L [(13.08 +/- 2.54)%, P < 0.01] and in the proliferative index at 200 microg/L [(17.82 +/- 3.02)%, P < 0.01] and 1,000 microg/L [(16.57 +/- 2.56)%, P < 0.05], but not at 12.5 microg/L [(10.43 +/- 2.38)% and (14.08 +/- 2.67)%, respectively] or 50 microg/L [(9.94 +/- 2.54)% and (14.56 +/- 2.80)%, respectively)]. The values at 200 or 1,000 microg/L as above were also significantly different from those at 12.5 or 50 microg/L. The percentage of CD(40)(+) cells [(48.25 +/- 6.63)%, (52.28 +/- 6.94)%] and delta mean fluorescence intensity (dMF; 42.94 +/- 10.24, 49.51 +/- 12.34) were significantly lower in thyrocytes in GD cocultures treated with 200 or 1,000 microg/L oPRL than those untreated [(58.38 +/- 6.62)% and 67.30 +/- 20.20] or treated with two other concentrations of oPRL. The percentage of HLA-DR + cells [(46.79 +/- 7.51)%, P < 0.01] and dMF (21.02 +/- 5.43, P < 0.01) were significantly higher in the thyrocytes treated with 50 microg/L oPRL than those untreated [(33.51 +/- 8.58)% and 13.91 +/- 3.88] or treated with three other concentrations. There were no significant differences between the dose groups of oPRL but those mentioned above.

CONCLUSIONS

Prolactin could affect interactions between GD PBMC and autologous thyrocytes and might eventually influence the shift of helper T cells. High prolactin levels might aggravate GD.

[An experimental study of a new route for Acyclovir administration for anti-keratitis therapeutic treatment]

OBJECTIVE

To study the significance of a collagen shield made by centrifugal method that can deliver Acyclovir.

METHODS

28 white rabbits were divided into four groups for observing releasing of Acyclovir into aqueous at 0.5, 1, 3, 5 hours after adding drugs in two different administrative ways, that were putting drug loaded collagen shields on one eye of the rabbit and subconjunctival injection of drug in another eye of the rabbit as control. The drug concentrations in aqueous of rabbit at different times using different administrative routes were measured by high-performance liquid chromatography (HPLC).

RESULTS

At 0.5 hr of drug administration, the Acyclovir concentrations in aqueous of subconjunctival injected rabbits were obviously higher than that in collagen shields loaded rabbits (t = 4.050, P <0.01), but it became not so notable at the time of 1 hr. (t =2.074, P>0.05). At the time of 3 hrs and 5 hrs, the drug concentrations in aqueous of collagen shield loaded eyes of the rabbits not only were higher than that of the subconjunctival injected rabbits (t=4.761, t=4.190, respectively, P <0.01), but also could sustain rather a long time.

CONCLUSIONS

A drug delivering way using collagen shield made by centrifugal method can replace the subconjunctival injection.

Extracellular mutations of protease-activated receptor-1 result in differential activation by thrombin and thrombin receptor agonist peptide

The protease-activated thrombin receptor-1 (PAR-1) can be activated by both the tethered ligand exposed by thrombin cleavage and a synthetic peptide having the tethered ligand sequence (thrombin receptor agonist peptide or TRAP). We conducted a mutational analysis of extracellular residues of the receptor potentially involved in interaction with both the tethered ligand and the soluble peptide agonist. Agonist-stimulated calcium efflux in X. laevis oocytes or inositol phosphate accumulation in COS-7 cells was used to assess receptor activation. We have also examined the binding of a radiolabeled TRAP for the wild-type and mutant PAR-1 receptors. Our results indicated that most of the mutations strongly affected TRAP-induced responses without significantly altering thrombin-induced responses or TRAP binding. Several point mutations and deletion of extracellular domains (DeltaEC3, DeltaNH3) drastically altered the ability of mutant receptors to respond to TRAP, but not to thrombin, and did not affect the affinity for the radiolabeled TRAP by these mutant receptors. Only mutations that disrupted the putative disulfide bond or substitution of multiple acidic residues in the second extracellular loop by alanine had a significant effect on both ligand binding and thrombin activation. These results suggest that although both agonists can activate PAR-1, there are profound differences in the ability of thrombin and TRAP to activate PAR-1. In addition, we have found PAR-1 mutants with the ability to dissociate receptor-specific binding from functional activity.

Effect of IFN-gamma, IL-4 on proliferation and synthesis of hyaluronic acid and collagen in cultured human retroorbital fibroblasts in vitro

OBJECTIVE

To investigate the cellular immune mechanism of thyroid associated ophthalmopathy (TAO) and provide a basis for treating TAO with cytokine or anti-cytokine agents, we determined whether interferon (IFN)-gamma and interleukin (IL)-4, representative cytokines of Th1 and Th2 cells, may have some effect on the development and progression of TAO.

METHOD

Retroorbital fibroblasts (RF) proliferation and the synthesis of hyaluronic acid (HA) and type IV collagen were measured with liquid scintillation and radioimmunoassay.

RESULTS

IFN-gamma stimulated RF proliferation and HA synthesis and had a significant inhibitory effect on type IV collagen synthesis. IL-4 stimulated proliferation and type IV collagen synthesis in RF and had inhibitory effect on HA synthesis. When IFN-gamma (100 U/ml) and IL-4 (1 microgram/L) were incubated together with RF, they antagonized their respective stimulatory or inhibitory effect on the proliferation and synthesis of HA and type IV collagen. Thyrotropin (TSH) stimulated RF proliferation and type IV collagen synthesis in a dose-dependent manner, while only at high dose (100 U/L and 200 U/L), stimulated RF to synthesize HA.

CONCLUSIONS

IFN-gamma, a representative cytokine of Th1 cells, is responsible for the inflammatory process of TAO; whereas IL-4, a representative cytokine of Th2 cells, has some effect on the repair process. IL-4 could antagonize the inflammatory effect of IFN-gamma on RF. TSH may have aggravating effect on the pathogenesis of TAO.

Body temperature of newborns: what is normal?

Medical records of 203 healthy full-term infants were reviewed to determine the range of axillary temperatures for newborn infants, factors that affect temperature and nursery management of infants with temperatures outside published normal ranges. The mean birth temperature was 36.5 degrees C (S.D. = 0.6 degrees C). Temperature was associated with birth weight (p<0.0005) and the presence of maternal fever (p<0.0001) but not with type of environment or time of birth. The mean temperature increased with age, rising 0.2 degrees C by 2-3 hours after birth (p<0.0001) and 0.3 degrees C by 15-20 hours (p<0.0001). Among a subset of 114 eligible neonates the mean temperature dropped 0.2 degrees C after bathing (p<0.0001). Although 17% of all temperatures measured were in the hypothermic (< or =36.3 degrees C) range, the only response recorded by nursery staff consisted of warming by modifying the environment, e.g., bundling. Blood cultures were drawn from 51 infants (25%), 43 because of maternal intrapartum antibiotic treatment for maternal fever or prolonged duration of ruptured amniotic membranes (>24 hours) and none for evaluation of abnormal temperatures. No infants had systemic infections and all were discharged in stable condition. Newborn axillary temperatures in our nursery were considerably lower than what has been previously described as "normal." Given the frequency of "hypothermia" and absence of associated illness, we believe the reference range for newborn temperatures should be expanded to include lower temperatures.

Syntheses, structures, and reactivities of heteroleptic magnesium amide thiolates

The syntheses and characterizations of a family of novel heteroleptic magnesium amide thiolates are presented. The compounds are synthesized by ligand redistribution chemistry involving reactions of equimolar amounts of magnesium amides and magnesium thiolates. Utilization of the smaller thiolates [Mg(SPh)2]n and [Mg(S-2,4,6-iPr3C6H2)2]n results in the isolation of dimeric species, [Mg(THF)(N(SiMe3)2)(mu-SR)]2 (R = Ph (1), 2,4,6-iPr3C6H2 (2)), with four-coordinate metal centers and bridging thiolate functions. The sterically more encumbered thiolate S-2,4,6-tBu3C6H2 induces the formation of the four-coordinate, monomeric species Mg(THF)2(N(SiMe3)2)(S-2,4,6-tBu3C6H2) (3)). Careful choice of reaction conditions allows the successful syntheses of pure heteroleptic compounds; however, it remains difficult to obtain the compounds in high yields, since a tendency toward product symmetrization and ligand redistribution under re-formation of the starting materials is prevalent. One of these symmetrized products is also included in this report: the dimeric, four-coordinate magnesium thiolate [Mg-(THF)(S-2,4,6-tBu3C6H2)(mu-S-2,4,6-tBu3C6H2)]2 (4), isolated as the product of the reaction between [Mg-(N(SiMe3)2)2]2 and Mg(THF)2(S-2,4,6-tBu3C6H2)2. All compounds were characterized by NMR and IR spectroscopy, elemental analyses, and X-ray crystallography. Crystal data obtained with Mo K alpha (lambda = 0.710 73 A) radiation are as follows. 1: C16H31MgNOSSi2, a = 11.2100(1) A, b = 17.4512(3) A, c = 11.2999(2) A, beta = 97.952(1) degrees, V = 2189.32(6) A3, Z = 4, monoclinic, space group P2(1)/n, R1 (all data) = 0.0934. 2: C25H49MgNOSSi2, a = 11.1691(1) A, b = 11.0578(1) A, c = 26.0671(4) A, beta = 99.906(1) degrees, V = 3171.44(6) A3, Z = 4, monoclinic, space group P2(1)/c, R1 (all data) = 0.0557. 3: C36H71MgNO3SSi2, a = 42.8293(16) A, b = 10.9737(5) A, c = 16.8305(7) A, beta = 98.755(3) degrees, V = 7818.1(6) A3, Z = 8, monoclinic, space group C2/c, R1 (all data) = 0.1331. 4: C80H132Mg2O2S4, a = 18.8806(2) A, b = 19.3850(2) A, c = 27.3012(4) A, beta = 97.250(1) degrees, V = 9912.4(2) A3, Z = 4, monoclinic, space group P2(1)/n, R1 (all data) = 0.1023.

Effect of immunoglobulin G from patients with Graves' ophthalmopathy and interferon gamma in intercellular adhesion molecule-1 and human leucocyte antigen-DR expression in human retroocular fibroblasts

OBJECTIVE

To detect the expression of intercellular adhesion molecule-1 (ICAM-1) and human leucocyte antigen-DR (HLA-DR) on retroocular fibroblasts (RFs) by immunoglobulin G (IgG) from patients with Graves' ophthalmopathy (GO) and interferon gamma (IFN-gamma) and to study the possible mechanism of humoral immunity and cellular immunity in the pathogenesis of GO.

METHODS

Purified IgG was obtained from 23 patients (GO 10, Graves' disease 9, toxic multinodular goiter 4) and 8 normal persons. Cytokine IFN-gamma and thyroid stimulating hormone (TSH) were incubated with normal human RF cultured in vitro. Antigen expression on RFs induced by stimulators was examined using immunofluoresence staining and a flow cytometer.

RESULTS

RFs spontaneously expressed ICAM-1, but did not express HLA-DR. All IgGs from patients with GO and other thyroid diseases as well as from normal persons could not stimulate the expression of ICAM-1 on RFs. IFN-gamma and TSH significantly enhanced the expression of ICAM-1 in dose-dependent manner (P < 0.05). Only IFN-gamma could stimulate RFs to express HLA-DR (P < 0.05).

CONCLUSIONS

IgG from patients with GO did not stimulate the expression of ICAM-1 and HLA-DR on the surface of cultured normal human RFs. IFN-gamma was the important factor for intiating and promoting autoimmune reactions in GO. We need to pay more attention to TSH, as it may possibly play a promoting role in the pathogenesis in GO.

Improvement in cerebral blood flow and metabolism following subarachnoid hemorrhage in response to prophylactic administration of the hydroxyl radical scavenger, AVS, (+/-)-N,N'-propylenedinicotinamide: a positron emission tomography study in rats

OBJECT

The hydroxyl radical scavenger (+/-)-N,N'-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.

METHODS

Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-D-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group). In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.

CONCLUSIONS

Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.

Disturbance of cerebral blood flow autoregulation in hypertension is attributable to ischaemia following subarachnoid haemorrhage in rats: A PET study

The effects of subarachnoid haemorrhage (SAH) on cerebral blood flow (CBF) autoregulation during induced hypertension were studied by positron emission tomography (PET) during chronic vasospasm in anaesthetized Sprague-Dawley rats. SAH was induced by intracisternal injection of autologous blood. In the control animals saline was injected instead. This method produced angiographical vasospasm of major arteries 48 h after injection. During this period, CBF was measured at each side of fronto-parietal and occipital sections using PET with or without induced hypertension. Mean arterial blood pressure (MABP) was increased from 94+/-2.4 to 140+/-0.3 mmHg by the injection of phenylephrine. An autoregulatory index (AI) expressed as delta CBF (%) per 10-mmHg increase in MABP was employed to analyse CBF response. SAH significantly reduced (p<0. 0001) basal CBF (ml/100 g/min) by 26.2% (control 60.0+/-1.9 n=24, SAH 44.3+/-4.5 n=20). A territorial CBF that decreased by 50% or more over the mean control value was used to define ischaemia and was identified in five out of 20 regions (25%) in the SAH group. AI (%/10-mmHg) was 13.5+/-2.4 in the control group (n=24). In the SAH group, AI decreased (p<0.05) to 4.5+/-2.5 in non-ischaemic areas (n=15), while in the ischaemic areas (n=5) AI increased (p<0.05) to 25.2+/-4.1. Since the spastic artery is intrinsically resistant to hypertension, the marked increase in CBF during hypertension can be attributable to ischaemia following SAH.

Expression of ICAM-1, B7.1 and TPO on human thyrocytes induced by IFN-alpha

OBJECTIVE

To detect expression of intercellular adhesion molecule-1 (ICAM-1), B7.1 and thyroid peroxidase (TPO) on thyrocyte and study the possible mechanism of interferon-alpha (IFN-alpha) in the pathogenesis of autoimmune thyroid disease (AITD).

METHODS

Thyrocytes were cultured from 6 normal persons. Antigen expression on thyrocytes induced by cytokines was examined using immunofluorescence staining with flow cytometer.

RESULTS

IFN-alpha significantly stimulated the expression of ICAM-1, B7.1 and TPO, as compared with those of control group. IFN-gamma markedly enhanced the expression of HLA-DR and ICAM-1, but not B7.1. Prolactin (PRL) resulted in increased expression of ICAM-1, B7.1, as well as overexpression of TPO, which is more significant than that stimulated by IFN-alpha.

CONCLUSIONS

Thyroid autoimmunity induced by IFN-alpha is associated with the expression of ICAM-1, B7.1 and TPO. IFN-gamma could not induce the expression of B7.1, therefore it is not an initiator in AITD. In addition, we should pay more attention to PRL which possibly plays an important role in the initiation and perpetuation of postpartum thyroiditis.

[Smoking, related cancers, and other diseases in shanghai: a 10-year prospective study]

OBJECTIVE

To explore the relationship between smoking and related diseases among residents of Shanghai.

METHODS

A cross-sectional study on current smoking status among 213,800 residents aged 20 yr and over in Shanghai urban, suburb and rural areas was carried out during the early 1980s. The residents in the urban area were followed up for 12 years (1983 - 1994) and those in suburb and rural areas for 11 years (1984 - 1994). A Poisson regression model was used to estimate relative risks RRs of certain diseases for smoking adjusted for age with their 95% confidence intervals by sex and area among persons aged 40 yr and over at the beginning of the study.

RESULTS

In the urban area, the RRs of death for smoking were 1.48 and 1.62 in males and females, respectively and for cancer death were 2.20 and 2.00. Statistically significant elevated RRs were seen for cancers of the lung and liver in both males and females and for cancers of the oesophagus, stomach, pancreas and bladder only in males. Significantly higher RRs were also observed for cerebrovascular disease, chronic bronchitis and emphysema, and pulmonary heart disease. RRs lower than in the urban area were found in the suburb and rural areas. The population attributable risks (%, PAR) for death due to smoking for males were estimated by area. PARs for death were 20.9, 18.9 and 16.3 in urban, suburb and rural areas, respectively. For all cancers, PARs were 40.0, 34.5 and 34.2 and for lung cancer were 71.7, 59.2 and 64.7.

CONCLUSION

Smoking was associated with the mortality of some common cancers, chronic bronchitis, and emphysema, pulmonary heart, and cerebrovascular diseases.

Epigenetic transcriptional silencing and 5-azacytidine-mediated reactivation of a complex transgene in rice

Despite a growing number of reports indicating non-Mendelian inheritance of transgene expression in monocots, no detailed description of the structure and stability of the transgene exists for transformants generated by direct DNA-transfer techniques, making the cause for these observations difficult to determine. In this paper we describe the complex organization of Btt cryIIIA and bar transgenes in rice (Oryza sativa L.) that displayed aberrant segregation in R1 progeny. Silencing rather than rearrangement of the bar gene was implicated because the herbicide-sensitive R1 plants had a DNA hybridization profile identical to that of the resistant R0 parent and R1 siblings. Genomic DNA analysis revealed substantial methylation of the Ubi1/bar sequences in silenced plants and, to a lesser degree, in herbicide-resistant plants, suggesting that the transgene locus was potentiated for silencing. Nuclease protection and nuclear run-on assays confirmed that silencing was due to transcriptional inactivation. Treatment of R2 progeny of silenced plants with 5-azacytidine resulted in demethylation of the Ubi1 promoter and reactivation of bar gene expression, demonstrating a functional relationship for methylation in gene silencing. These findings indicate that methylation-based silencing may be frequent in cereals transformed by direct DNA protocols that insert multiple, often rearranged sequences.

Effect of Ca2+ on GP IIb-IIIa interactions with integrilin: enhanced GP IIb-IIIa binding and inhibition of platelet aggregation by reductions in the concentration of ionized calcium in plasma anticoagulated with citrate

BACKGROUND

Integrilin (eptifibatide), a potent inhibitor of the fibrinogen binding function of GP IIb-llla, has been shown to reduce the thrombotic complications of angioplasty and of acute coronary syndromes. The present study was designed to determine whether the reduced Ca2+ concentrations in plasma anticoagulated with citrate affect Integrilin binding to GP IIb-IIIa and the ex vivo pharmacodynamic measurements for this drug.

METHODS AND RESULTS

Lower concentrations of Integrilin were found to inhibit platelet aggregation in plasma anticoagulated with citrate (for ADP, mean+/-SD IC(50)=140+/-40 nmol/L, n=6; Ca2+ =40 to 50 micromol/L) than with PPACK (IC(50)=570+/-70 nmol/L, P<.0001, n=6; Ca2+ approximately 1 mmol/L). Chelation of Ca2+ with EDTA or citrate caused a similar degree of enhancement in the inhibitory activity of Integrilin. Measurements of D3 LIBS epitope expression showed that the enhanced inhibitory activity was caused by enhanced GP IIb-IIIa occupancy by Integrilin. Citrate anticoagulation decreased the amounts of Integrilin required to inhibit the binding of PAC1, a monoclonal antibody that mimics the GP IIb-IIIa binding activity of fibrinogen. Reduced Ca2+ also increased Integrilin inhibition of the binding of biotinylated fibrinogen to purified, immobilized GP IIb-IIIa.

CONCLUSIONS

These data suggest that citrate anticoagulation removes Ca2+ from GP IIb-IIIa and enhances the apparent inhibitory activity of Integrilin. This finding indicates that the inhibitory activity of Integrilin is overestimated in blood samples collected with citrate, suggesting that it may be possible to achieve greater antithrombotic efficacy beyond that observed in clinical trials to date with Integrilin.

Ligand cross-reactivity within the protease-activated receptor family

Recently, a second member of the protease-activated receptor (PAR) family, named PAR-2, has been identified. Similar to the thrombin receptor, PAR-2 appears to be activated by proteolytic-mediated exposure of a "tethered ligand" sequence and can also be activated by the corresponding synthetic peptides. Similarities in the amino acid sequence of the receptors' tethered ligand sequences suggest that their respective agonist peptides might not be absolutely specific for their particular receptors. To test this, the receptor specificity of each agonist has been determined by measuring the responses of Xenopus oocytes expressing the thrombin receptor or PAR-2 to agonist peptides or enzymes. Thrombin receptors responded to thrombin, the human thrombin receptor-activating peptide SFLLRNP-NH2 (TRAP) (EC50 = 0.1 microM), and Xenopus TRAP, TFRIFD-NH2 (EC50 = 1 microM), but did not show any increase in calcium efflux over control levels with trypsin (50 nM) or PAR-2 agonist peptides (100 microM). Human and murine PAR-2 receptors responded comparably to human and murine PAR-2 agonist peptides (SLIGKVD and SLIGRL, respectively) (EC50 = 0.5-2.0 microM) and trypsin, but not to thrombin. PAR-2 was also found to be responsive to TRAP (EC50 = 1 microM) but was unresponsive to Xenopus TRAP (50 microM). Responses to additional peptide agonist analogs suggest that an amino-terminal serine is critical for PAR-2 agonist activity.

[Effects of human interferon-alpha on periphral blood mononuclear cells of the patients with autoimmune thyroid disease]

Interferon-alpha (IFN-alpha) therapy for hepatitis and malignant tumor frequently results in autoimmune thyroid disease (AITD); this fact indicates an association of IFN-alpha with autoimmunity. In order to study the mechanism, an investigation of the effects of human IFN-alpha on T cells, T cell subpopulations, B cells, macrophages and natural killer cells of patients with AITD and normal controls was carried out. It has been found that T cells were inhibited by IFN-alpha with dosage dependency, particularly the T suppressor (CD8/CD11b) in both the patients with AITD and normal controls. An increase in number of B cells and macrophages with stimulation of IFN-alpha was also found in both groups. The results suggest that the decrease of suppressive T cells and increase B cells and macrophages may be responsible for IFN-alpha induced autoimmunity.

Relation of electron beam computed tomography screening for coronary calcium to cardiovascular risk and disease: a review

Electron beam computed tomography has become an increasingly popular technology to noninvasively screen for coronary artery calcium as a marker of atherosclerotic burden. Coronary artery calcium is invariably associated with atherosclerosis, and the amount (volume, mass, or calculated 'score') of calcium is directly associated with age, male gender, and other cardiovascular risk factors. Coronary artery calcium is highly sensitive and moderately specific for the identification of angiographically significant disease. Recent reports also show a direct association between the amount of coronary calcium and the risk of combined new coronary events and revascularization in previously asymptomatic individuals, and hard coronary events among symptomatic patients. Coronary artery screening by electron beam computed tomography is a cost-effective tool compared with other diagnostic modalities when the pre-test likelihood of disease is low to moderate. Although some reports have shown significant retest variability in calcium scores obtained from repeated scans, and in the individual relationship between angiographic disease and coronary calcium quantity, such variability may be minimized by averaging results from two or more consecutive scans, techniques to minimize respiratory motion artifact, and possibly the use of thicker scan slice thicknesses. Serial scanning by electron beam computed tomography is also being investigated as a noninvasive tool for following the effects of medical or lifestyle intervention for controlling cardiovascular risk factors or disease. At present, coronary artery scanning by electron beam computed tomography may be most appropriately utilized in screen patients with established coronary risk factors or known or suspected coronary disease, and in combination with established diagnostic testing to confirm the presence of suspected coronary disease.