Constraints on Lightly Ionizing Particles from CDMSlite

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7}  cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5  MeV/c^{2} to 100  TeV/c^{2}) and cover a wide range of βγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with βγ as small as 0.1 for the first time.

Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated above Ground

We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst)  eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140  MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.

Evolution of diverse Hall effects during the successive magnetic phase transitions in Mn2.5Fe0.6Sn0.9 Kagome-lattice alloy

Evolution of diverse Hall effects due to successive magnetic transitions has been observed in Mn_2.5Fe_0.6Sn_0.9 by suitable chemical substitution of Fe in Mn_3.1Sn_0.9. This noncollinear antiferromagnetic alloy exhibits a Neel temperature of 325 K. Upon cooling from 325 K, a magnetic phase transition from noncollinear antiferromagnetism to ferromagnetism occurs at 168 K due to the tilting of magnetization towards c axis. Above this temperature, anomalous Hall resistivity ranged from 0.6 to 1.3 μΩ cm has been observed in noncollinear antiferromagnetic state. Below this temperature, a topological Hall effect (THE) starts to appear due to the non-vanishing scalar spin chirality arising from the noncoplanar spin structure. Further decreasing temperature to 132 K, another magnetic transition happens, resulting in the coexistence of ferromagnetism and antiferromagnetism, so that a Hall plateau with large hysteresis below 70 K is yielded. A hysteresis as high as ∼80 kOe is obtained in ρ _xy -H at 15 K. However, the Hall plateau disappears and only anomalous Hall effect (AHE) persists when further decreasing the temperature to 5 K. The present study provides a picture of diverse magneto-transport properties correlated to the variable spin structures driven by magnetic phase transitions.

[Clinicopathological characteristics and outcomes of 122 patients with colorectal cancer metastasize to the ovary]

Objective: To explore the clinicopathological characteristics and prognosis of patients with ovarian metastases from colorectal cancer. Methods: A total of 122 female patients with ovarian metastases from colorectal cancer underwent treatment in Cancer Hospital, Chinese Academy of Medical Sciences between 2010 and 2015 were recruited. The clinicopathological features, treatment details and survival data of these patients were retrospectively analyzed. Kaplan-Maier method was used for survival analysis, log rank test and Cox proportional hazards model were used for prognostic factor analysis. Results: The median overall survival (OS) was 19.7 months. The 1-year, 3-years and 5-years OS rates were 72.1%, 24.7% and 9.9%, respectively. A total of 99 (81.1%) patients underwent oophorectomy. The median OS of patients who underwent oophorectomy was 21.9 months, significantly longer than 10.3 months of patients without oophorectomy (P<0.01). Ovary as the only site of metastasis, primary tumor resection, and oophorectomy were associated with improved survival (all P<0.01). Primary tumor resection and oophorectomy were independent prognostic factors for OS (both P<0.01). Conclusion: Patients with ovarian metastases from colorectal cancer might acquire a survival benefit from surgical resection of the primary tumor and ovaries.

[Analysis of metastatic colorectal cancer patients treated with regorafenib in real-world practice]

Objective: To evaluate the dose, efficacy and tolerability of regorafenib in a real-world clinical setting of metastatic colorectal cancer patients. Methods: The clinical data of patients with metastatic colorectal cancer who had received at least two previous treatment lines treated with regorafenib from May 2018 to December 2019 at National Cancer Center/Cancer Hospital was retrospectively analyzed. Patients'demographics, treatment, dosimetry, safety and survival data were collected. The primary endpoint was overall survival (OS). Results: A total of 114 patients were enrolled in this study, including male 83 and female 31, with a median age of 61.Of all patients, 83 were treated with regorafenib and 31 were given combination therapy with regorafenib. Starting dose was 80 mg in 57 (50.0%) patients, 120 mg in 24 (21.1%) patients, and 160 mg in 28 (24.6%) patients. Dose increases were observed in 30.9% (25/81) of patients receiving 80 mg and 120 mg as the initial dose. Forty-five (39.5%) and 36 (31.6%) patients took the last daily dose of 80 mg and 120 mg, respectively. Median follow-up time was 8.5 months.Objective response rate (ORR) and disease control rate(DCR) were 1.0% and 52.1%, respectively. The median progression free survivalrate (PFS) was 2.4 moths (95%CI: 0.80-10.57), median OS was 11.0 moths(95%CI: 9.03-not available). The difference of the PFS and OS in the different dose groups was not statistically significant. But patients who received 120 mg regorafenib showed much longer survival with a median OS of 16.7 month. The difference of survival between the regorafenib group and combination group was not statistically significant either. Twenty patients continued with regorafenib as treatment even after progression. These patients had longer survival compared with those (n=52) who stopped regorafenib with median OS of 16.7 month vs 9.1 month (χ(2)=2.305, P=0.116), respectively.There were 7.9%(9/114) of the patients who discontinued regorafenib therapy because of the adverse event, such as hand-foot skin reaction (HFSR), gastrointestinal bleeding, proteinuria and liver function injury. Conclusions: Patients with advanced colorectal cancer who failed to respond to standard therapy have a good survival benefit. The initial dose of 120 mg of regorafenib has a better risk/benefit ratio and is more suitable for patients with advanced colorectal cancer.

[Preliminary study of the relationship between novel coronavirus pneumonia and liver function damage: a multicenter study]

Objective: To analyze the clinical characteristics of cases of novel coronavirus pneumonia and a preliminary study to explore the relationship between different clinical classification and liver damage. Methods: Consecutively confirmed novel coronavirus infection cases admitted to seven designated hospitals during January 23, 2020 to February 8, 2020 were included. Clinical classification (mild, moderate, severe, and critical) was carried out according to the diagnosis and treatment program of novel coronavirus pneumonia (Trial Fifth Edition) issued by the National Health Commission. The research data were analyzed using SPSS19.0 statistical software. Quantitative data were expressed as median (interquartile range), and qualitative data were expressed as frequency and rate. Results: 32 confirmed cases that met the inclusion criteria were included. 28 cases were of mild or moderate type (87.50%), and four cases (12.50%) of severe or critical type. Four cases (12.5%) were combined with one underlying disease (bronchial asthma, coronary heart disease, malignant tumor, chronic kidney disease), and one case (3.13%) was simultaneously combined with high blood pressure and malignant tumor. The results of laboratory examination showed that the alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBil) for entire cohort were 26.98 (16.88 ~ 46.09) U/L and 24.75 (18.71 ~ 31.79) U/L, 39.00 (36.20 ~ 44.20) g/L and 16.40 (11.34 ~ 21.15) μmol/L, respectively. ALT, AST, ALB and TBil of the mild or moderate subgroups were 22.75 (16.31 ~ 37.25) U/L, 23.63 (18.71 ~ 26.50) U/L, 39.70 (36.50 ~ 46.10) g/L, and 15.95 (11.34 ~ 20.83) μmol/L, respectively. ALT, AST, ALB and TBil of the severe or critical subgroups were 60.25 (40.88 ~ 68.90) U/L, 37.00 (20.88 ~ 64.45) U/L, 35.75 (28.68 ~ 42.00) g/L, and 20.50 (11.28 ~ 25.00) μmol/L, respectively. Conclusion: The results of this multicenter retrospective study suggests that novel coronavirus pneumonia combined with liver damage is more likely to be caused by adverse drug reactions and systemic inflammation in severe patients receiving medical treatment. Therefore, liver function monitoring and evaluation should be strengthened during the treatment of such patients.

[Analysis of acute sinusitis or nasal furuncle derived orbitalcellulitis in children: review of 18 cases]

Objective:To analyze the diagnosis and treatment of acute sinusitis or nasal furuncle derived periorbital cellulitis in children.Method:The clinical data of 18 children with acute sinusitis or nasal furuncle derived orbital cellulitis was analyzed retrospectively.Result:Sixteen cases(88.89%) had acute sinusitis and 2(11.11%) had furuncle of nose.All cases were treated with antibiotics and steroids.And 16 cases were cured and the other two received surgery.The median length of hospitalization was 7.33 days(5-13 days).Conclusion:Sufficient antibiotics combined with steroids and local treatment is critical in treating pediatric orbital cellulitis.Timely and decisive surgical intervention can effectively control the progression of disease.

[Research advances in the aortic remodeling after thoracic endovascular aortic repair therapy of Stanford type B aortic dissection]

Aortic dissection is one of the most common vascular emergent disease. Thoracic endovascular aortic repair (TEVAR) therapy which created the new era of treatment of Stanford type B aortic dissection (TBAD) has gradually replaced the surgical treatment and becomes the gold standard for treatment of TBAD. Aortic remodeling after TEVAR is the key factor to evaluate the mid-term survival rate and successful treatment of the aortic dissection victims. However, there are few studies on aortic remodeling and lack of unified criteria to evaluate it. This article was to summarize the domestic and abroad research advances which focused on the morphological changes, the regularity, and the evaluation criteria of aorta remodeling after TEVAR.

[Effect of inhibiting perivascular adhesion on intimal hyperplasia of the vein grafts in rabbits]

Objective: To investigate the effect of preventing perivascular adhesion with topical application of sodium hyaluronate on intimal hyperplasia of the vein grafts in rabbits. Methods: Twenty-four male New Zealand white rabbits, aged 5 months, were randomly divided into 2 groups: Group A and B (n=12 rabbits per group). Artery defect model was established by cutting about 1 cm artery from the middle part of the dissociated left common carotid artery. A section about 3 cm was cut from the right external jugular vein, and the harvested vein was inverted and end-to-end anastomosed to the artery defect. After anastomosis, the adventitia and two anastomosis of the grafted veins in group A was applied 0.2 ml sodium hyaluronate locally to, and corresponding site in Group B was served as a control, but with the sterile normal saline. The grafted veins were obtained 1, 2 and 4 weeks after operation, HE staining and Masson staining were preformed for histological changes of grafted vein wall, proliferating cell nuclear antigen (PCNA) and platelet-derived growth factor (PDGF) immunohistochemistry staining were conducted for proliferation and expression and distribution of PDGF of the grafted vein. Results: The macroscopic and histological observation showed that the perivascular adhesions in Group A were looser when compared with those in Group B. The thickness of the intima, the degree of intima hyperplasia of 2 groups at different time points were as follows: at 1 week after operation, group A[(25.5±3.9) μm, (1.2±0.1) ]and group B[(26.2±4.2)μm, (1.2±0.1)]; at 2 weeks after operation, group A[(44.3±2.5)μm, (1.2±0.1)]and group B[(51.0±3.8)μm, (1.4±0.0)]; at 4 weeks after operation, group A[(69.9±6.8)μm, (1.5±0.1)] and group B[(84.4±6.4)μm, (1.7±0.1)]. Group A was inferior to group B in terms of the above three parameters 2 and 4weeks after operation (P<0.05). Cell proliferation index of intima and that of media were as follows: at 1 week after operation, group A (7.4±2.2), (21.5±3.2) and group B (11.5±2.0), (28.6±4.5); at 2 weeks, group A (20.0±3.2), (35.8±3.4) and group B (26.8±4.1), ( 42.6±4.2); at 4 weeks, group A (11.4±2.0), (22.1±2.7) and group B (15.5±2.4, 28.6±3.9). Group A was inferior to group B in terms of cell proliferation index of intima and media 1, 2 and 4 weeks after operation (P<0.05). The percentage of PDGF-positive cells of intima, media and adventitia was as follows: at 1 week after operation, group A (7.7±1.6), (19.6±3.7), (2.5±1.5) and group B (7.6±2.4), (20.6±4.4), (10.3±2.3); at 2 weeks after operation, group A (11.4±2.6), (19.8±3.1), (12.9±3.3) and group B (19.5±3.5), ( 30.6±5.2), (30.5±5.8); at 4 weeks after operation, group A (6.2±1.9), ( 11.1±2.8), (10.2±2.4) and group B (10.5±2.0), (18.6±3.2), (26.5±3.8). Group A was inferior to group B in terms of the percentage of PDGF-positive cells of intima, media and adventitia 2 and 4 weeks after operation (P<0.05) and Group A was inferior to group B that of adventitia 1 week after operation (P<0.05). Conclusion: Preventing perivascular adhesion with topical application of sodium hyaluronate can inhibit intimal hyperplasia.

The influence of age at menarche, menstrual cycle length and bleeding duration on time to pregnancy: a large prospective cohort study among rural Chinese women

OBJECTIVE

To investigate the relations among age at menarche (AAM), menstrual cycle length, menstrual bleeding duration and time to pregnancy in a large cohort of rural Chinese women.

DESIGN

A prospective cohort study.

SETTING

Local family-planning service agencies and maternal/child care service centres.

POPULATION

A total of 391 320 rural women of reproductive age who participated in the National Free Pre-pregnancy Checkups and were planning to conceive were enrolled.

METHODS

Menstrual characteristics were collected via face-to-face interviews. The Cox proportional hazards model were used to estimate the fecundability ratios (FRs) and 95% confidence intervals for each measure relative to its reference category.

MAIN OUTCOME MEASURES

Time to pregnancy.

RESULTS

Women with an AAM later than 14 years of age were less likely become pregnant compared with women with AAM at 13-14 years of age (FR 0.93, 95% CI 0.92-0.94). Those with menstrual cycle lengths >29 days were less likely to come pregnant (FR 0.91, 95% CI 0.90-0.92) compared with the reference cycle length of 27-29 days. Women with bleeding durations of <4 (FR 0.88; 95% CI 0.86-0.91) or >5 days (FR 0.91; 95% CI 0.90-0.91) showed lower FRs compared with those reporting 4-5 days of bleeding. The associations were independent of maternal age, ethnicity, education level, occupation, tobacco use, alcohol use and body mass index.

CONCLUSION

A later onset of menarche, longer menstrual cycle length, both shorter (<4 days) and longer (>5 days) bleeding duration were associated with a lower FR and longer time to pregnancy in rural Chinese women.

TWEETABLE ABSTRACT

A later menarche, longer cycle, shorter or longer bleeding duration were associated with lower fecundity.

The reversal of the spontaneous exchange bias effect and zero-field-cooling magnetization in La1.5Sr0.5Co1−xFexMnO6: the effect of Fe doping

The temperature-dependent magnetization reversal and spontaneous exchange bias sign switching are simultaneously achieved in La_1.5Sr_0.5CoMnO₆ by Fe ion doping.

Chromosome 7 translocation breakpoints in male carriers: clinical features and implications for genetic counseling

Balanced reciprocal translocations are associated with reproductive failure. Some reciprocal translocation carriers exhibit azoospermia or oligozoospermia, and an association exists between these chromosomal abnormalities and recurrent abortion. Previous reports have indicated the involvement of chromosome 7 translocations in male infertility and recurrent miscarriage. A translocation breakpoint can occur within an important gene, interrupting its structure and leading to male infertility. However, clinical characteristics resulting from chromosome 7 translocation breakpoints have not been studied. Here, we report such breakpoints and their associated clinical features, to enable informed genetic counseling of carriers. Balanced reciprocal translocations were found in 1.57% of the tested patients. Among these 82 individuals, 14 (17.07%) carried a chromosome 7 translocation, of which, five presented with pregestational infertility and clinical manifestations of oligozoospermia or necrospermia, while nine presented with gestational infertility (i.e., were able to conceive, but often resulting in miscarriage). Breakpoints at 7q31 and 7q36 were associated with pregestational infertility, whereas those at 7p10, 7q21.2, 7q22, and 7q32 were connected to gestational infertility. However, the breakpoint at 7p15 was associated with both. Chromosome 7 translocation carriers with pregestational or gestational infertility should be counseled on chromosomal breakpoints and the various molecular technologies available for assisted reproduction.

Translocation breakpoints of chromosome 1 in male carriers: clinical features and implications for genetic counseling

Reciprocal translocation is closely associated with male infertility and recurrent miscarriages. Balanced reciprocal translocations associated with reproductive failures are predominantly observed on chromosome 1. Additionally, infertile male patients present a number of breakpoints throughout chromosome 1. A translocation breakpoint might interrupt the structure of an important gene, leading to male infertility. Here, we report the breakpoints on chromosome 1 translocation and the clinical features presented in carriers, to enable informed genetic counseling of these patients. Balanced reciprocal translocations were found in 1.57% of the tested patients. Among 82 patients, 23 patients (28.05%) were carriers of the chromosome 1 translocation: 12 presented pre-gestational infertility with clinical manifestations of azoospermia or oligozoospermia, while 11 patients presented gestational infertility (able to conceive but with a tendency to miscarry or give birth to a stillborn). The breakpoint at 1p22 was predominantly observed in these patients; additionally, breakpoints at 1p31.2, 1p10, and 1q25 were associated with gestational infertility. Breakpoints at 1p13, 1q12, and 1q21 were associated with pre-gestational infertility. These results suggested that breakpoints at 1p32, 1p13, and 1q21 were predominantly associated with pre-gestational infertility, while that at 1q25 was associated with gestational infertility. Chromosome 1 translocation carriers with infertility presenting as azoospermia or oligospermia should be counseled on chromosomal breakpoints and the different molecular technologies available to facilitate reproduction.

[A case of nasopharyngeal inflammatory myofibroblastic tumorafter radiotherapy of nasopharyngeal carcinoma]

Inflammatory myofibroblastic tumor（IMT）is composed of the cable shape myofibroblastic cells which constitute soft tissue tumors.IMT is mostly encountered in the lung, its occurrence in the head and neck is relatively rare. Herein, we reported 1 case of IMT after radiotherapy of nasopharyngeal carcinoma(NPC)in the nasopharynx.The clinical symptoms and nasal pharynx imaging findings of IMT are similar to the NPC.Thus,the pathological and immunohistochemistrical examinations maybe helpful to make a correct diagnosis.

Role of ABCB1 C1236T, G2677T, and C3435T genetic polymorphisms in the development of acute leukemia in a Chinese population

We carried out a case-control study to examine the relationship between the ATP-binding cassette subfamily B member 1 (ABCB1) gene polymorphisms C1236T, G2677T, and C3435T and risk of acute leukemia in a Chinese population. Between May 2013 and April 2015, we recruited 164 acute leukemia patients and 285 healthy controls, and determined polymorphism genotypes by polymerase chain reaction-restriction fragment length polymorphism. Using unconditional logistic regression analysis, we observed that in comparison to the wild-type sequence, the TT genotype [odds ratio (OR) = 2.15, 95% confidence interval (CI) = 1.12-4.10; P = 0.01] and the T allele (OR = 1.39, 95%CI = 1.05-1.86; P = 0.02) of ABCB1 G2677T were associated with acute leukemia susceptibility. The TT genotype (OR = 2.03, 95%CI = 1.11- 3.69; P = 0.01) and the T allele (OR = 1.39, 95%CI = 1.05-1.85; P = 0.02) of the C3435T polymorphism also increased acute leukemia risk compared to the wild-type form. However, no significant relationship was established between the ABCB1 C1236T variant and this disease. Our results suggest that the ABCB1 G2677T and C3435T sequence variations may affect susceptibility to acute leukemia.

Balanced reciprocal translocation at amniocentesis: cytogenetic detection and implications for genetic counseling

Balanced translocation is a common structural chromosomal rearrangement in humans. Carriers can be phenotypically normal but have an increased risk of pregnancy loss, fetal death, and the transmission of chromosomal abnormalities to their offspring. Existing prenatal screening technologies and diagnostic procedures fail to detect balanced translocation, so genetic counseling for carriers remains a challenge. Here, we report the characteristics of chromosomal reciprocal translocation in 3807 amniocentesis cases. Of the 16 detected cases of fetal reciprocal translocation, 8 cases (50%) showed positive biochemical marker screening; 3 cases (18.75%) were the parental carriers of a chromosomal abnormality; 2 (12.5%) were of advanced maternal age, 2 (12.5%) had a previous history of children with genetic disorders, and 1 case (6.25%) was associated with positive soft markers in obstetric ultrasound. Chromosomes 5 and 19 were the most commonly involved chromosomes in balanced translocations. Of the 13 cases with fetal balanced translocations, 8 (61.5%) were inherited from a paternal chromosome, 3 (23.1%) from a maternal chromosome, and 2 (15.4%) cases were de novo. The incidence of balanced translocation at amniocentesis was 0.42%. Male carriers of reciprocal chromosome translocation appear to have a higher chance of becoming a parent of a child born by normal childbirth than female carriers.

De novo interstitial deletion in the long arm of chromosome 11: a case report

The 11q terminal deletion disorder is a rare genetic disorder associated with numerous clinical features. A few case reports have been made about de novo interstitial deletion of chromosome 11q. However, due to the heterogeneity in size and position of the deletions, a clear genotype-phenotype correlation is not easily made. Here we report a case interstitial 20.5-Mb deletion at chromosome 11q13.4q21, as confirmed by array comparative genomic hybridization. Dysmorphic features such as coarse facial features, congenital laryngomalacia, oblique inguinal hernia, high-arched palate, and camptodactyly were observed in the subject. The present case broadens the spectrum of clinical findings observed in individuals with 11q interstitial deletion.

[Investigation of renal corticomedullary differentiation with age-related change on non-contrast-enhanced MRI]

OBJECTIVE

To evaluate the relationship between renal corticomedullary differentiation, renal cortical thickness and age-related changes with non-contrast-enhanced steady-state free precession(SSFP) magnetic resonance imaging (MRI) and spatially selective inversion recovery(IR) pulse technology as well as its applied value .

METHODS

A total of 76 healthy volunteers had been recruited from August 2014 to June 2015 in First Hospital of China Medical University.All volunteers were divided into three groups: 2-40 years old, 41-60 years old, 61-80 years old. All 76 volunteers underwent non-contrast-enhanced steady-state free precession(SSFP) 3.0 T MRI scan using variable inversion times (TIs)(TI=1 000, 1 100, 1 200, 1 300, 1 400, 1 500, 1 600, 1 700 ms). The renal corticomedullary differentiation was observed and the signal intensity of renal cortex and medulla were measured respectively as well in order to calculate renal corticomedullary contrast ratio. Besides, renal cortical thickness and renal size were measured.

RESULTS

All 76 volunteers were successfully performed all the sequences of MRI scan, including 152 useful imaging of kidney in total. The renal corticomedullary differentiation was clearly shown in all subjects. There was negative correlation between the optimal inversion time(TI) and age(r=-0.65, P<0.01). Similarly, negative correlation was observed between renal corticomedullary contrast ratio and age(r=-0.35, P<0.01). The mean renal cortical thickness of all subjects was (5.33±0.71)mm and there were statistically significant difference among those different groups, which was negative-related with age(r=-0.79, P<0.01). There was no statistically significant difference between sexuality and renal cortical thickness.Additionally, renal cortical thickness had no statistically significant difference in both sides of kidneys.

CONCLUSION

The renal corticomedullary differentiation is depicted clearly by means of non-contrast-enhanced steady-state free precession MRI with spatially selective inversion recovery pulse technology. The optimal inversion time decreases along with the increase of age. In the meanwhile, the renal cortical thickness could be measured truthfully and accurately.

An outbreak of Candida parapsilosis fungemia among preterm infants

In this article, we describe the first outbreak of Candida parapsilosis fungemia in our hospital. We examined a cluster of four nosocomial cases of C. parapsilosis fungemia that occurred in the neonatal intensive care unit (NICU) of the Affiliated Xingtai People's Hospital of Hebei Medical University over a two-week period. We ascertained patient parameters including clinical characteristics, blood and sputum cultures, and drug sensitivity test results. Cultures from eight blood samples obtained from the four infected preterm infants showed identical characteristics and were identified as C. parapsilosis. In order to determine the infection-related factors and to control the spread of the infection among the population, we immediately initiated the emergency plan. All four of the preterm infants recovered from the infection; there were no deaths. Outbreaks of C. parapsilosis, mostly involving preterm infants of very low birth weight or extremely low birth weight, can and do occur in NICUs. Cultures prepared using multiple samples taken from different patients contribute to a more definitive diagnosis. Established measures that control and prevent the infection, as well as effective and comprehensive treatments, can lead to a favorable outcome. That is to say, improving both disinfection and isolation, as well as interrupting the pathway of transmission, is the key to controlling the spread of infection.

Physiological evaluation of the responses of Larix olgensis families to drought stress and proteomic analysis of the superior family

The conifer Larix olgensis has been analyzed to delineate physiological and proteomic changes that occur under drought stress. Studies of the deleterious effects of drought in the larch families have mainly focused on photosynthesis. In the present study, when the intensity of drought was increased, plant height was inhibited as both POD and MDA levels increased, which indicates oxidative stress. Two-dimensional gel electrophoresis analysis detected 23 significantly differentially expressed proteins, of which 18 were analyzed by peptide mass fingerprinting by using MALDI-TOF/TOF. Eight spots were found to be up-regulated, while the other 10 spots were down-regulated during drought stress. The proteins that were induced by drought treatment have been implicated in the physiological changes that occurred. These results could provide additional information that could lead to a better understanding of the molecular basis of drought-sensitivity in larch plants.

Graphene based quantum dots

Laterally localized electronic states are identified on a single layer of graphene on ruthenium by low temperature scanning tunneling spectroscopy (STS). The individual states are separated by 3 nm and comprise regions of about 90 carbon atoms. This constitutes a highly regular quantum dot-array with molecular precision. It is evidenced by quantum well resonances (QWRs) with energies that relate to the corrugation of the graphene layer. The dI/dV conductance spectra are modeled by a layer height dependent potential-well with a delta-function potential that describes the barrier for electron penetration into graphene. The resulting QWRs are strongest and lowest in energy on the isolated 'hill' regions with a diameter of 2 nm, where the graphene is decoupled from the surface.

Identifying multiple configurations of complex molecules in dynamical processes: time resolved tunneling spectroscopy and density functional theory calculation

We report for the first time a new methodology to determine molecular configurations of a large molecular complex in a dynamical process on a metal surface by combining time-resolved tunneling spectroscopy (I-t) and density functional theory calculation (DFT). Two examples, (t-Bu)4-ZnPc and FePc, representing molecular rotation and lateral diffusion on Au(111) surfaces, respectively, were applied to demonstrate our method. Through analysis of statistical occupation time for each configuration, the molecular configuration numbers and energy differences between different configurations of these molecular systems could be unambiguously determined. These experimental results are further compared with DFT calculation to determine corresponding molecular configurations. Importantly, through the spatial I-t mapping, valuable insights of molecular surface diffusion paths are obtained.

Detection of hepatitis B virus markers using a biosensor based on imaging ellipsometry

A biosensor based on imaging ellipsometry (BIE) has been developed and validated in 169 patients for detecting five markers of hepatitis B virus (HBV) infection. The methodology has been established to pave the way for clinical diagnosis, including ligand screening, determination of the sensitivity, set-up of cut-off values (CoVs) and comparison with other clinical methods. A matrix assay method was established for ligand screening. The CoVs of HBV markers were derived with the help of receiver operating characteristic curves. Enzyme-linked immunosorbent assay (ELISA) was the reference method. Ligands with high bioactivity were selected and sensitivities of 1 ng/mL and 1 IU/mL for hepatitis B surface antigen (HBsAg) and surface antibody (anti-HBs) were obtained respectively. The CoVs of HBsAg, anti-HBs, hepatitis B e antigen, hepatitis B e antibody and core antibody were as follows: 15%, 18%, 15%, 20% and 15%, respectively, which were the percentages over the values of corresponding ligand controls. BIE can simultaneously detect up to five markers within 1 h with results in acceptable agreement with ELISA, and thus shows a potential for diagnosing hepatitis B with high throughput.

Constructing an array of anchored single-molecule rotors on gold surfaces

Molecular rotors with a fixed off-center rotation axis have been observed for single tetra-tert-butyl zinc phthalocyanine molecules on an Au(111) surface by a scanning tunneling microscope at LN2 temperature. Experiments and first-principles calculations reveal that we introduce gold adatoms at the surface as the stable contact of the molecule to the surface. An off-center rotation axis is formed by a chemical bonding between a nitrogen atom of the molecule and a gold adatom at the surface, which gives them a well-defined contact while the molecules can have rotation-favorable configurations. Furthermore, these single-molecule rotors self-assemble into large scale ordered arrays on Au(111) surfaces. A fixed rotation axis off center is an important step towards the eventual fabrication of molecular motors or generators.

Phase response characteristics of sinoatrial node cells

In this work, the dynamic response of the sinoatrial node (SAN), the natural pacemaker of the heart, to short external stimuli is investigated using the Zhang et al. model. The model equations are solved twice for the central cell and for the peripheral cell. A short current pulse is applied to reset the spontaneous rhythmic activity of the single sinoatrial node cell. Depending on the stimulus timing either a delay or an advance in the occurrence of next action potential is produced. This resetting behavior is quantified in terms of phase transition curves (PTCs) for short electrical current pulses of varying amplitude which span the whole period. For low stimulus amplitudes the transition from advance to delay is smooth, while at higher amplitudes abrupt changes and discontinuities are observed in PTCs. Such discontinuities reveal critical stimuli, the application of which can result in annihilation of activity in central SAN cells. The detailed analysis of the ionic mechanisms involved in its resetting behavior of sinoatrial node cell models provides new insight into the dynamics and physiology of excitation of the sinoatrial node of the heart.

Different role of Apaf-1 in positive selection, negative selection and death by neglect in foetal thymic organ culture

Apoptotic protease-activating factor 1 (Apaf-1) is a component of the apoptosome which is required for the activation of procaspase-9. As Apaf-1 knockout (KO) (Apaf-1-/-) mice die before birth, the role of Apaf-1 during thymic selection was investigated using 5 day foetal thymic organ culture (FTOC) of thymi obtained at gestational day 15. There was a lower ratio of CD4 single-positive (SP) to CD8 SP cells and decreased apoptosis of CD4+CD8+ (DP) thymocytes from Apaf-1-/- mice compared with wild-type. To determine if these defects resulted in increased production of neglected thymocytes, the Apaf-1-/- mice were crossed with the T-cell receptor (TCR)-alpha-chain KO mice. There was no difference in thymocyte development in the thymi of TCR-alpha-/-Apaf-1-/- and TCR-alpha-/-Apaf-1+/+ mice 5 days after FTOC. To determine if Apaf-1 is involved in apoptosis during death by negative or positive selection, FTOC of the thymus of Apaf-1-/- Db/HY TCR-alphabeta transgenic (Tg) mice was carried out. There was decreased apoptosis of the HY clonal-specific M33+ thymocytes and an increased percentage of the autoreactive CD8+M33+ thymocytes in male, but not female Apaf-1-/- Db/HY TCR Tg mice. Our data suggest that Apaf-1 is not involved in positive selection or death by neglect, but may have a partial role in negative selection during early thymic T-cell development.

Regulation of apoptosis of synovial fibroblasts

In 1992, the first gene to cause systemic autoimmune disease in mice was identified as the Fas gene that is mutated in lymphoproliferative (lpr mice). These mice exhibited a defect in activation-induced cell death of T cells and B cells in vivo. This leads to the failure of proper clearance and removal of immune cells and defective downmodulation of an immune response. This then leads to the speculation that apoptosis defects, including defects in Fas, Fas ligand and Fas apoptosis signaling, may play a role in defective downmodulation of the hyperimmune response observed in human autoimmune diseases. Over the past 7 years, many scientists have analyzed different proapoptotic genes such as Fas, Fas ligand, Bcl-X, caspases as well as antiapoptosis pathways including defects in Fas and Fas ligand, Bcl-2 and caspase inhibitors. Potential genetic defects have been analyzed at the RNA, protein and functional level in humans with autoimmune disease. Somewhat surprisingly, most studies indicate that there is excessive apoptosis of PBMCs in autoimmune disease and human autoimmune disease suggesting that human autoimmune disease is not due to defective apoptosis of immune cells. Some studies indicate that there is decreased apoptosis of parenchymal cells such as RASF that undergo hyperplasia. Gene therapy and other modulators of apoptosis, such as wortmannin, can be used to faciliate apoptosis of RASF.

Activated CD8(+) T cells from aged mice exhibit decreased activation-induced cell death

To uncouple the defects of activation and apoptosis of T cells from aged mice, we used anti-CD3 plus IL-2 stimulation to induce an activation response and analyzed the subsequent activation-induced cell death (AICD) response of T cells from 16-month-old mice. The results herein demonstrate that T cells from 16-month-old mice could be activated by anti-CD3-induced activation signals but exhibited distinct phenotypic and functional features compared to young (2-month-old) mice. These include a decrease in AICD, a delayed entry into the cell cycle, and a decreased telomerase activity. The decreased AICD of T cells from 16-month-old mice is associated with a decreased expression of Fas and Fas ligand (FasL), decreased susceptibility to anti-Fas-induced apoptosis, and an increased expansion of a CD8(+) T-cell population. Prior to activation, these T cells exhibit a phenotype that is CD44(hi)CD62L(hi). After stimulation, these T cells produced high levels of the pro-inflammatory cytokine, IFN-gamma, and developed an increased population of IFN-gamma(+)IFN-gamma R(-) T cells. Our results suggest that there is a dysregulation in T-cell homeostasis in aged mice associated with a decrease in AICD of CD8(+) T cells.

Normal T-cell response and in vivo magnetic resonance imaging of T cells loaded with HIV transactivator-peptide-derived superparamagnetic nanoparticles

The present study analyzed the feasibility of using magnetic resonance imaging (MRI) to monitor T-cell homing in vivo after loading T cells with superparamagnetic iron oxide (CLIO) nanoparticles derivatized with a peptide sequence from the transactivator protein (Tat) of HIV-1. T cells were isolated from C57BL/6 (B6) mice and loaded with 0, 400, 800, 1600, or 8000 ng/ml of FITC conjugated CLIO-Tat (FITC-CLIO-Tat). There was a dose-dependent uptake of FITC-CLIO-Tat by T cells. Stimulation of FITC-CLIO-Tat loaded T cells with anti-CD3 (0.1 microg/ml) plus IL-2 (5 ng/ml) elicited normal activation and activation-induced cell death (AICD) responses, and normal upregulation of CD69, ICAM-1 (CD54), L-selectin (CD62L), and Fas. The FITC-CLIO-Tat loaded T cells (3 x 10(7)) were transferred intravenously (i.v.) into B6 mice and the in vivo MRI of mice was acquired using a spin-echo pulse sequence at 4.7 T with a Bruker Biospec system. Homing of T cells into the spleen was observed by a decrease in MRI signal intensity within 1 h after the transfer, which remained decreased for 2-24 h after transfer. These homing data were confirmed by FACS analysis and biodistribution analysis using 125I-CLIO-Tat. Thus, T cells can be efficiently loaded with FITC-CLIO-Tat without interfering with their normal activation and AICD, or homing to the spleen, and the biodistribution of FITC-CLIO-Tat loaded T cells can be monitored in vivo over time by MRI.

Defective Fas ligand-mediated apoptosis predisposes to development of a chronic erosive arthritis subsequent to Mycoplasma pulmonis infection

OBJECTIVE

To determine whether defective T cell apoptosis is associated with the development of a chronic arthritis subsequent to mycoplasma infection, and to determine whether deletion of T cells can prevent the development of this arthritis.

METHODS

B6 wild-type (B6-+/+), B6-lpr/lpr, and B6-gld/gld mice were infected with Mycoplasma pulmonis. The severity of lymphocytic infiltration and joint damage was evaluated, and the degree of recovery of viable mycoplasma from the spleen and joints was determined. Antigen-presenting cells derived from Fas mutant lpr mice (lpr-APC) were transfected ex vivo with an adenovirus (Ad) vector to yield lpr-APC expressing high levels of Fas ligand (lpr-APC-AdFasL), which in turn were transferred intraperitoneally into M pulmonis-infected B6-gld/gld mice. The development of arthritis subsequent to M pulmonis infection and the induction of apoptosis of cells within the synovial tissue and lymph nodes of lpr-APC-AdFasL-treated B6-gld/gld mice were determined.

RESULTS

Infection of B6-lpr/lpr and B6-gld/gld mice with M pulmonis resulted in an acute-phase inflammation of the synovium that later developed into a chronic erosive arthritis. Similar infection of B6-+/+ mice resulted only in an acute joint inflammatory response that resolved. Chronic arthritis in B6-gld/gld mice and B6-lpr/lpr was not due to persistent infection, since there were no differences in the rates of clearance of M pulmonis from the joints of B6-gld/gld or B6-lpr/lpr mice compared with B6-+/+ mice. Treatment of infected B6-gld/gld mice with lpr-APC-AdFasL resulted in a significantly decreased incidence of chronic arthritis that was associated with a decrease in lymph node T cells, but not with apoptosis of synovial T cells or fibroblasts.

CONCLUSION

Defective Fas/FasL-mediated apoptosis of T cells is an important factor that rendered arthritis-resistant B6 mice susceptible to the development of a chronic erosive arthritis subsequent to mycoplasma infection. In vivo lpr-APC-AdFasL cell-gene therapy is a safe and effective method for inhibiting the development of this arthritis.

Regulation of tumor necrosis factor alpha-mediated apoptosis of rheumatoid arthritis synovial fibroblasts by the protein kinase Akt

OBJECTIVE

To determine if tumor necrosis factor alpha (TNFalpha)-driven proliferation of rheumatoid arthritis synovial fibroblasts (RASF) is associated with up-regulation of the activity of serine/threonine kinase B/Akt and with survival of RASF.

METHODS

Staining of phosphorylated Akt was done using anti-phosphorylated Thr308 Akt antibody. Levels of phosphorylated Akt were analyzed by Western blot and Akt activity was analyzed using a kinase assay. TUNEL staining was used to analyze the cytotoxicity of TNFalpha treatment or TNFalpha combined with either the Akt activity inhibitor wortmannin, an adenovirus expressing dominant-negative mutant (AdAkt-DN), or an adenovirus expressing phosphatase and tensin homolog deleted on chromosome 10 (AdPTEN).

RESULTS

The levels of phosphorylated Akt were higher in RASF than in osteoarthritis synovial fibroblasts (OASF), as demonstrated by immunohistochemical staining, immunoblot analysis, and an Akt kinase assay. The levels of phosphorylated Akt and Akt kinase activity were increased by stimulation of primary RASF with TNFalpha (10 ng/ml). Treatment of RASF with the phosphatidylinositol 3-kinase inhibitor wortmannin (50 nM) plus TNFalpha resulted in apoptosis of 60 +/- 8% (mean +/- SEM) of RASF within 24 hours. This proapoptosis effect was specific for Akt, since equivalent levels of apoptosis were observed upon TNFalpha treatment of RASF transfected with AdAkt-DN and with AdPTEN, which opposes the action of Akt.

CONCLUSION

These results indicate that phosphorylated Akt acts as a survival signal in RASF and contributes to the stimulatory effect of TNFalpha on these cells by inhibiting the apoptosis response. This effect was not observed in OASF and may reflect the pathophysiologic changes associated with the proliferating synovium in rheumatoid arthritis.

Genetic dissection of age-related changes of immune function in mice

Understanding of the genetic basis of normal and abnormal development of the immune response is an enormous undertaking. The immune response, at the most minimal level, involves interactions of antigen presenting cells (APCs), T and B cells. Each of these cells produce cell surface and soluble factors (cytokines) that affect both autocrine and paracrine functions. A second level of complexity needs to consider the development of the macrophage/monocyte lineage as well as the production of the common lymphoid precursor which undergoes distinct maturation steps in the thymus and periphery to form mature T cells as well as in BM (BM) and lymphoid organs to form mature B cells. A third level of complexity involves the immune response to infectious agents including viruses and also the response to tumour antigens. In addition, there are imbalances that predispose to decreased responses (immunodeficiencies) or increased responses (autoimmunity). A fourth level of complexity involves attempts to understand the differences in the immune response that occurs at a very young age, in adults, and at a very old age. This review will focus on the use of C57BL/6 J X DBA/2 J (BXD) recombinant inbred (RI) strains of mice to map genetic loci associated with the production of lymphoid precursors in the BM, development of T cells in the thymus, and T-cell responses to stimulation in the peripheral lymphoid organs in adult and in aged mice. Strategies to improve the power and precision in which complex traits such as the age-related immune response can be mapped is limited with the current set of 35 strains of BXD mice. Strategies to increase these strains by generating recombinant intercross (RIX) strains of mice are being developed to enable this large set of lines to detect quantitative trait loci (QTLs) with a much higher consistency and statistical power. More importantly, the resolution with which these QTLs can be mapped would be greatly improved and, in many cases, adequate to carry out direct identification of candidate genes. It is likely that, given the complexity of the immune system development, the number of cells involved in an immune response, and especially the changes in the immune system with ageing, mapping hundreds of genes will be required to fully understand age-related changes in the immune response. This review outlines ongoing and future strategies that will enable the mapping and identification of these genes.

An Oral Health Survey in Southern China, 1997: background and methodology

Relatively limited information is available about the oral health in the Guangdong Province of Southern China, the closest neighbor to Hong Kong. The study intended to explore the oral health status, knowledge, attitudes, and dental care utilization in the Guangdong population as a basis for formulating strategies for oral health prevention and treatment. Through multi-stage stratified and quota-sampling, individuals from urban as well as rural communities were selected (5- to 6-; 12-; 35- to 44-; and 65- to 74-year-olds; total N = 6251). Structured interviews and clinical examinations were performed. Inter-examiner reliability was high (kappa = 0.60-0.96). Samples of community water were taken for fluoride assessment. Overall, the sample surveyed was acceptably representative of the population, with some under-representation of rural residents and agricultural workers. Re-weighting was performed in appropriate analyses. The data analysis model used in the Second International Collaborative Study was used as a guide for the present data analysis. This approach has not previously been used on a Mainland Chinese population.

Coronal and root caries in Southern Chinese adults

Southern China is the most prosperous part of China, but information useful for oral care planning is very limited. A large-scale epidemiological survey was conducted in 1996-97. The objectives of this report were to describe the coronal and root caries of the adult Southern Chinese and to analyze the influence of selected demographic and socio-economic factors on the disease pattern. A total sample of 1,573 35- to 44-year-olds and 1,515 65- to 74-year-olds from 8 urban and 8 rural survey sites in Guangdong Province participated in an oral health interview and underwent clinical examination. World Health Organization examination procedures and diagnostic criteria were used. The weighted mean DMFT scores of the middle-aged and the elderly subjects were 4.8 and 16.1, respectively. People living in rural areas had a higher DMFT score than those living in urban areas (4.9 vs. 4.3 in the 35- to 44-year-olds and 16.5 vs. 14.7 in the 65- to 74-year-olds). In both age groups, MT was the major component of the DMFT score. Analysis of covariance showed that women and those who were economically less well off had higher DMFT scores in both age groups. The weighted prevalence rates of decayed/filled roots were 12% and 37%, with a mean of 0.2 and 0.7 teeth affected, in the middle-aged and the elderly, respectively. In conclusion, socio-economic factors had a considerable effect on the dental caries status of adults in Southern China.

Recombinant adenovirus expressing adeno-associated virus cap and rep proteins supports production of high-titer recombinant adeno-associated virus

It has been difficult to produce a chimeric vector containing both Ad and AAV rep and cap, and to grow such chimeric vectors in 293 cells. By recombination in vitro in a bacterial host, we were able to produce recombinant plasmid AdAAV (pAdAAVrep-cap), which could be used to generate recombinant AdAAV (rAdAAVrep-cap) after transfection into 293 cells. A recombinant adenovirus, rAdAAVGFP, in which the green fluorescent protein (GFP) gene is flanked by the AAV terminal repeats cloned into the E1-deleted site of Ad was also generated. Co-infection of rAdAAVrep-cap together with rAdAAVGFP into 293 cells resulted in production of high titers of rAAV expressing GFP. It was noted that the titer of rAdAAVrep-cap was lower than the titer of control AdCMVLacZ. The lower titer of rAdAAvrep-cap was associated with expression of Rep protein. Non-homologous recombination occurs after high passage and results in deletions within the AAV rep genes. These results indicate that (1) rAdAAVrep-cap can be produced; (2) rAdAAVrep-cap + rAdAAVGFP is a convenient and efficient way to transfect 293 cells to grow high titer rAAV; and (3) frozen stock is required to avoid propagation of rep-deleted pAdAAVrep-cap.

Oral health status and oral health behaviors in Chinese Children

The objectives of the study were to describe the oral health status and treatment needs of the 5- to 6-year-old and 12-year-old children in Southern China; to describe the patterns of oral health behaviors, knowledge, and attitudes among the 12-year-olds; and to assess the effects of socio-behavioral factors on the 12-year-old children's dental caries experiences. The study sample was comprised of 1,587 5- to 6-year-old and 1,576 12-year-old urban and rural schoolchildren living in Guangdong Province. Three calibrated dentists clinically examined the children, and trained interviewers interviewed the 12-year-olds. Caries prevalence of the 5- to 6-year-old children was high (urban 78% vs. rural 86%); the mean dmft of the urban and rural children was 4.8 and 7.0, respectively. The caries prevalence and mean DMFT score of the 12-year-olds were 41% and 0.9 (urban) and 42% and 0.9 (rural). Only 2% of the 12-year-olds exhibited no calculus or gingival bleeding, while more than 70% had calculus. In conclusion, there is an urgent need for establishing caries-preventive activities for preschool children. The prevalence of caries among the 12-year-olds was not high, but their periodontal condition was unsatisfactory. Knowledge about gum bleeding and the use of fluoride was low. More oral health education activities should be organized, especially for the rural children.

Tooth loss, occluding pairs, and prosthetic status of Chinese adults

The objectives of this analysis were to describe the numbers of teeth lost and those indicated for extraction, dental prosthetic status, and occluding tooth pairs among adults in Southern China and to investigate factors affecting tooth mortality. A sample consisting of 1,573 35- to 44-year-old and 1,515 65- to 74-year-old urban and rural Chinese was examined clinically by calibrated examiners. Teeth not present for any reason were defined as missing (MT). The sum of MT and teeth indicated for extraction (IMT) was defined as adjusted missing teeth (AMT). Only 4.4% of the urban and 3.4% of the rural 65- to 74-year-olds were edentulous. MT were not significantly different between urban and rural residents, but more IMT were found in rural residents. Women, those who had a lower education level, and those who were less wealthy had more AMT in both age groups. Smoking was found to be associated with AMT in the 35- to 44-year-olds. Eighteen percent of the urban and 27% of the rural elderly had no occluding tooth pairs after IMT were accounted for, and only 38% and 30%, respectively, had 10 or more occluding pairs. Fifty-one percent of the urban and 43% of the rural elderly were found to have some form of dental prostheses in either jaw. A partial denture was more common in urban residents in both age groups.

Treatment of chronic sialadenitis in a murine model of Sjögren's syndrome by local fasL gene transfer

OBJECTIVE

Infection of Fas (Fas/CD95)-mutant C57BL/6 (B6)-lpr/lpr mice with murine cytomegalovirus (MCMV) leads to a chronic sialadenitis similar to that of Sjögren's syndrome (SS). The aim of this study was to evaluate whether chronic sialadenitis would also occur in Fas ligand (FasL/CD95L)-mutant B6-gld/gld mice upon infection with MCMV and whether the expression of FasL by local gene transfer using recombinant adenoviral vectors would be an effective therapeutic strategy.

METHODS

B6-gld/gld mice were infected intraperitoneally with MCMV, and salivary glands were analyzed histologically at different time points. For treatment of sialadenitis, recombinant adenoviral vectors expressing the fasL gene (AdLoxpFasL + AxCANCre) or the lacZ gene (AdCMVLacZ) were locally injected into the salivary glands of MCMV-infected B6-gld/gld mice and uninfected B6-+/+ and B6-gld/gld mice.

RESULTS

Following MCMV infection, B6-gld/gld mice developed an acute and chronic sialadenitis characterized by multiple foci of infiltrating T cells. After local injection of adenoviral vectors, high levels of lacZ or fasL gene expression could be detected in acinar and ductal cells. Treatment of acute and chronic sialadenitis in B6-gld/gld mice with local fasL gene transfer resulted in a significant reduction in the number of inflammatory foci and tissue destruction in salivary glands compared with mice treated with AdCMVLacZ. Despite high levels of FasL expression after injection of recombinant vectors, <5% of ductal and acinar cells were TUNEL positive, demonstrating that, in this model of SS, acinar and ductal cells were not highly sensitive to FasL-mediated apoptosis.

CONCLUSION

Chronic sialadenitis similar to that of SS developed in B6-gld/gld mice after MCMV infection. FasL expression was reconstituted by local gene transfer, resulting in significant reduction of infiltrating mononuclear cells, which indicates that local gene transfer of fasL might be a novel treatment for chronic sialadenitis.

Aged mice exhibit in vivo defective peripheral clonal deletion of D(b)/H-Y reactive CD8(+) T cells

We previously reported that T cells from aged mice were resistant to activation-induced cell death (AICD) in vitro. To determine whether the presence of AICD-resistant T cells is associated with defects in age-related peripheral clonal deletion in vivo, congenic male SCID mice were reconstituted with T cells from aged or young female D(b)/H-Y TCR (Tg71) transgenic mice. Compared with recipients of young cells, the recipients of T cells from aged mice exhibited a 3-fold increase in the percentage of autoreactive CD8(+) H-Y antigen-reactive T cells as defined by the clonotypic antibody, M33. There were significantly increased sera levels of interferon-gamma, a significantly decreased expression of FasL by M33(+)CD8(+) T cells, and significantly decreased apoptosis by DNA fragmentation staining of the spleen of mice reconstituted with T cells from aged mice compared to those from young mice. By day 21, the recipients of T cells from aged mice but not young mice, exhibited infiltration of CD3(+) cells into the non-lymphoid organs. These results indicate that there is defective peripheral deletion of the self-reactive T cells derived from aged female Tg71 mice, and that failure to delete these cells is associated with the defective T-cell clonal deletion in the recipient mice.

Apoptosis and rheumatoid arthritis: past, present, and future directions

The current studies of apoptosis in rheumatoid arthritis (RA) suggest that molecules (Fas-related or TNF-related), pathways (activation of pro-apoptosis or anti-apoptosis pathway), cell types (lymphocytes or synovial fibroblast), and the mechanism that triggers apoptosis (tolerance induction-related, down-modulation of inflammation-related, or DNA damage-related) all play a fundamental role to determine the induction or prevention of RA. These series of defects at different levels and in different cells lead to hyperproliferation, defective apoptosis, or hyperapoptosis. This review summarizes the available knowledge of apoptosis and RA to help identify candidate target cells and target molecules for delivery of gene constructs or modified biological or chemical reagents to the target site for effective modification of these cells.

Mutation of the hematopoietic cell phosphatase (Hcph) gene is associated with resistance to gamma-irradiation-induced apoptosis in Src homology protein tyrosine phosphatase (SHP)-1-deficient "motheaten" mutant mice

To determine the role of Src homology protein tyrosine phosphatase (SHP-1) in the ionizing radiation-induced stress response, we analyzed the apoptotic response and cell cycle function in irradiated spleen cells of motheaten (me/me) mice. The defect in me/me mice has been attributed to mutations of the HCPH: gene, which encodes SHP-1. Homozygotes develop severe systemic autoimmune and inflammatory disease, whereas heterozygotes live longer and develop hematopoietic and lymphoid malignance. Spleen cells from C57BL/6 (B6)-me/me and B6-+/+ controls were analyzed after gamma-irradiation from a (137)Cs source. B6-me/me cells were significantly more resistant than B6-+/+ cells to gamma-irradiation-induced apoptosis exhibiting a higher LD(50). The defective apoptosis response of the B6-me/me cells was exhibited by T and B cells and macrophages. Of the Bcl-2 family members analyzed, a significant difference was observed in the transcription of Bax mRNA, which was up-regulated early after irradiation in B6-+/+ cells, but not B6-me/me cells. Analysis of 3,3'-dihexyloxacarbocyanine iodide revealed resistance to the gamma-irradiation-induced mitochondrial transmembrane permeability transition in the B6-me/me cells. The blocking of the cell cycle in the G(0)/G(1) phase characteristic of the irradiated B6-+/+ cells was not observed in the B6-me/me cells. There was decreased phosphorylation of p38 mitogen-activated protein kinase and increased phosphorylation of p53 from spleen cell lysates of irradiated B6-me/me mice compared with wild-type mice. These data suggest that SHP-1 plays an important role in regulation of apoptosis and cell cycle arrest after a gamma-irradiation-induced stress response.

The Fas signaling connection between autoimmunity and embryonic lethality

The first gene to cause systemic autoimmune disease in mice was identified as the fas gene, which is mutated in lymphoproliferative (lpr) mice. These mice exhibited a defect in activation-inducted cell death of T cells and B cells in vivo, causing a failure of proper clearance of immune cells and defective down-modulation of an immune response. This led to the speculation that apoptosis defects may play a role in defective down-modulation of the hyperimmune response observed in human autoimmune diseases. More recently, scientists have generated different mouse lines with defects in Fas-apoptosis-associated molecules such as FADD and Apaf-1. These mice, however, died during embryonic development and did not develop autoimmune disease. These findings suggest that molecules associated with Fas apoptosis signaling can be important at the most limited levels for development of the immune system but also have more global apoptosis roles in other systems. We propose that the more global role of Fas-associated apoptosis molecules should be considered when evaluating their role in autoimmune disease.

Adeno-associated virus production of soluble tumor necrosis factor receptor neutralizes tumor necrosis factor alpha and reduces arthritis

The major limitation of adenovirus is its association with induction of an inflammatory response and relatively short-term production of the gene therapy transgene product. Adeno-associated virus (AAV) is a 4.68-kb single-strand DNA virus that contains ITRs for viral replication and a packaging signal, and also has been engineered to contain therapeutic genes up to 5 kb in length. Transduction of recombinant AAV (rAAV) results in low inflammatory response and long-term expression. We have cloned a low-immunogenic form of human sTNFRI (sTNFRI2.6D) into AAV (rAAVsTNFRI). This vector was analyzed for its ability to transfect and neutralize the effect of TNF-alpha on primary rheumatoid arthritis synovial fibroblast (RASFs). The rAAVsTNFRI was transduced into the cells at 1.8 x 10(1), 1.8 x 10(2), and 1.8 x 10(3) viral particles per cell. There was greater than 90% neutralization of TNF-alpha at 1.8 x 10(3) viral particles/cell. There was a significant decrease in the synovial cell hyperplasia and cartilage and bone destruction in human TNF-alpha transgenic mice treated intraarticularly with rAAVsTNFRI. These results indicate that the low-immunogenic and long-term expressing vector, rAAVsTNFRI, can be used to deliver the soluble TNF-alpha in vitro and in vivo and effectively reduce the severity of arthritis.

Gene therapy that inhibits nuclear translocation of nuclear factor kappaB results in tumor necrosis factor alpha-induced apoptosis of human synovial fibroblasts

OBJECTIVE

Tumor necrosis factor alpha (TNFalpha) increases the survival and proliferation of human rheumatoid arthritis (RA) cell lines. These experiments were designed to determine if inhibition of nuclear factor kappaB (NF-kappaB) nuclear translocation leads to increased apoptosis of TNFalpha-treated human RA cell lines.

METHODS

We constructed an inhibitor of nuclear factor kappaB(IkappaB) dominant-negative adenovirus (AdCMVIkappaB-DN) and an X-linked inhibitor of apoptosis (XIAP) antisense adenovirus (AdCMVXIAP-AS). Primary RA synovial fibroblast (RASF) cell lines were transfected in vitro, and SV40-transformed RA synovial cell lines in SCID mice were transfected in vivo. Cells were treated with TNFalpha and analyzed for apoptosis.

RESULTS

There was no apoptosis of primary RASF transfected in vitro with AdCMVIkappaB-DN alone. In contrast, there was apoptosis of >85% of cells treated with AdCMVIkappaB-DN plus TNFalpha. Primary RASF in SCID mice also exhibited high levels of apoptosis after in vivo transfection with AdCMVIkappaB-DN followed by treatment with TNFalpha. There was no apoptosis after treatment with AdCMVIkappaB-DN in the absence of TNFalpha. XIAP is an inhibitor of apoptosis which was up-regulated by TNFalpha, and this up-regulation was inhibited by AdCMVIkappaB-DN plus TNFalpha. Transfection of an AdCMVXIAP-AS gene therapy resulted in increased TNFa-induced apoptosis.

CONCLUSION

AdCMVIkappaB-DN gene therapy greatly enhances apoptosis due to inhibition of an NF-kappaB-mediated antiapoptosis signaling pathway, and XIAP is a TNFalpha-inducible specific inhibitor of apoptosis in RA synovial cell lines. This and other modulators of TNF receptor or the Fas apoptosis pathway may be therapeutically beneficial in facilitating apoptosis of synovial tissue in patients with RA.