Quantifying Tissue Properties of the Optic Radiations Using Strategically Acquired Gradient Echo Imaging and Enhancing the Contrast Using Diamagnetic Susceptibility Weighted Imaging

Visualization of the optic radiations is of clinical importance for diagnosing many diseases and depicting their anatomic structures for neurosurgical interventions. In this study, we quantify proton density, T1, T2*, and susceptibility of the optic radiation fiber bundles in a series of 10 healthy control participants using strategically acquired gradient echo imaging. Furthermore, we introduce a novel means to enhance the contrast of the optic radiations using diamagnetic susceptibility weighted imaging.

The potential of cadmium ion-immobilized Rhizobium pusense KG2 to prevent soybean root from absorbing cadmium in cadmium-contaminated soil

AIMS

Because the effect of Cd2+ -immobilized microbe on Cd uptake of plants in Cd-contaminated soil remains underexplored, this study focuses on the effect of Cd2+ -immobilized rhizobia on Cd uptake of soybean.

METHODS AND RESULTS

Strain KG2 from soybean nodule was identified as Rhizobium pusense KG2 by phylogenetic analysis. Rhizobium pusense KG2 showed the 120 mg l-1 of minimal lethal concentration for Cd2+ . In 50 and 100 mg l-1 of Cd2+ liquid, approximately 2 × 1010 cells removed 56·71 and 22·11% of Cd2+ , respectively. In pot soil containing 50 and 100 mg kg-1 of Cd2+ , strain KG2 caused a 45·9 and 35·3% decrease in soybean root Cd content, respectively. Meanwhile, KG2 improved the root and shoot length, nitrogen content and biomass of soybean plants and superoxide dismutase activity.

CONCLUSIONS

The Cd2+ -immobilized rhizobia could inhibit soybean plants to absorb Cd2+ from soil, promote plant growth and improve plant's tolerance against Cd. This study is the first time to report that R. pusense is an effective nodulating rhizobium of legume.

SIGNIFICANCE AND IMPACT OF THE STUDY

Some Cd2+ -immobilized microbe lowering Cd uptake of plant and promoting plant growth should be considered as an effective strategy for producing safety crops in the Cd-contaminated agricultural soil.

Glioma cells promote angiogenesis through the release of exosomes containing long non-coding RNA POU3F3

OBJECTIVE

Angiogenesis is a key event in the progression of gliomas, and emerging evidence suggests that exosomes are signaling extracellular organelles that modulate the tumor microenvironment and promote angiogenesis and tumor progression. This study aimed to explore the mechanism by which glioma-derived exosomes affect angiogenesis.

MATERIALS AND METHODS

qRT-PCR was used to determine the expression level of linc-POU3F3 in glioma tissue as well as glioma cell lines. Ultrafiltration combined with a purification method was used to isolate exosomes derived from A172 cells (A172-Exo) and linc-POU3F3 shRNA-treated A172 cells (shA172-Exo). Transmission electron microscopy, Western blot and tunable resistive pulse sensing (TRPS) were used to identify exosomes. In vitro migration, proliferation, and tube formation experiments, as well as in vivo CAM assays, were used to analyze the pro-angiogenesis ability of exosomes. qRT-PCR and Western blot were used to identify expression levels of angiogenesis-related genes and proteins in human brain microvascular endothelial cells (HBMECs) after being cultured with exosomes.

RESULTS

The levels of linc-POU3F3 were upregulated in glioma tissue and significantly correlated with the advanced tumor stage. A172 cells exhibited the highest expression level. A172-Exo was similar to shA172-Exo (50-100 nm in diameter) and expressed Alix, Tsg101 and CD9, while the expression level of linc-POU3F3 in A172-Exo was significantly higher than that in shA172-Exo. HBMECs rapidly internalized A172-Exo and shA172-Exo, and the linc-POU3F3 expression level in HBMECs treated with A172-Exo was significantly higher than the level in HBMECs treated with shA172-Exo. A172-Exo exhibited better function in promoting HBMECs migration, proliferation, tubular-like structure formation in vitro and arteriole formation in vivo. The gene and protein expression level of bFGF, bFGFR, VEGFA, and Angio in HBMECs treated with A172-Exo was much higher than that of HBMECs treated with shA172-Exo.

CONCLUSIONS

These results indicated that gliomas can induce angiogenesis by secreting exosomes enriched in linc-POU3F3. Exosomes and lncRNA-POU3F3 may, therefore, function as a putative therapeutic target in glioma.

[Research progress of the mechanisms underlying cadmium-induced carcinogenesis]

Since cadmium is an indirect genotoxic carcinogen, epigenetic modifications could be one of the major mechanisms underlying cadmium-induced carcinogenesis. It has been proposed that epigenetic alterations might be associated with cadmium-induced carcinogenesis, such as disruptions of DNA methylation, histone modifications, and microRNA expression profile, which would result in abnormal expression of carcinogenesis-related genes and/or imbalance of signal transduction pathways. Other mechanisms of cadmium-induced carcinogenesis consist of disruption of gene regulation and signaling pathways, repression of DNA repair, suppression of apoptosis, induction of oxidative stress and autophagy. Here, we reviewed the research of both epigenetic and non-epigenetic mechanisms underlying cadmium-induced carcinogenesis.

Vitamin D Status and the Risk of Recurrent Stroke and Mortality in Ischemic Stroke Patients: Data from a 24-Month Follow-Up Study in China

PURPOSE

In this study, we determined serum 25-hydroxyvitamin D [25(OH) D] levels in serum, and investigated their associations with risk of recurrent stroke and mortality in a 24-month follow up study in Chinese patients with first-ever ischemic stroke.

METHODS

In this preplanned post hoc analysis, serum levels of 25(OH) D and NIH stroke scale (NIHSS) were measured at the time of admission in a cohort of patients with ischemic stroke. We used logistic regression model to assess the relationship between 25(OH) D levels and risk recurrent stroke or mortality.

RESULTS

The follow-up rate was 98.2% in 220 stroke patients. Of 216 patients, 18.5% (95%CI: 13.3%-23.7%) patients had a stroke recurrence, and 30.1% (95% CI: 24.0%-36.2%) died. After adjustment for traditional risk factors, serum 25(OH) D levels were negatively associated with the risk of stroke recurrence (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.70-0.85; P < 0.001) and negatively associated with mortality during 24 months of follow-up (OR, 0.72; 95% CI, 0.64-0.80; P< 0.001). Compared with the first quartile of serum 25(OH) D levels, the ORs for stroke recurrence and mortality were as follows: second quartile, 0.80 (95% CI, 0.63-0.93) and 0.77 (95% CI, 0.65-0.89); third quartile, 0.42 (95% CI, 0.31-0.55) and 0.39 (95% CI, 0.30-0.52); fourth quartile, 0.12 (95% CI, 0.07-0.19) and 0.10 (95% CI, 0.06-0.15), respectively.

CONCLUSIONS

Lower serum levels of 25(OH) D are independently associated with the stroke recurrence and mortality at 24 months in ischemic stroke patients.

RAM-SCB simulations of electron transport and plasma wave scattering during the October 2012 "double-dip" storm

Mechanisms for electron injection, trapping, and loss in the near-Earth space environment are investigated during the October 2012 "double-dip" storm using our ring current-atmosphere interactions model with self-consistent magnetic field (RAM-SCB). Pitch angle and energy scattering are included for the first time in RAM-SCB using L and magnetic local time (MLT)-dependent event-specific chorus wave models inferred from NOAA Polar-orbiting Operational Environmental Satellites (POES) and Van Allen Probes Electric and Magnetic Field Instrument Suite and Integrated Science observations. The dynamics of the source (approximately tens of keV) and seed (approximately hundreds of keV) populations of the radiation belts simulated with RAM-SCB is compared with Van Allen Probes Magnetic Electron Ion Spectrometer observations in the morning sector and with measurements from NOAA 15 satellite in the predawn and afternoon MLT sectors. We find that although the low-energy (E< 100 keV) electron fluxes are in good agreement with observations, increasing significantly by magnetospheric convection during both SYM-H dips while decreasing during the intermediate recovery phase, the injection of high-energy electrons is underestimated by this mechanism throughout the storm. Local acceleration by chorus waves intensifies the electron fluxes at E≥50 keV considerably, and RAM-SCB simulations overestimate the observed trapped fluxes by more than an order of magnitude; the precipitating fluxes simulated with RAM-SCB are weaker, and their temporal and spatial evolutions agree well with POES/Medium Energy Proton and Electron Detectors data.

Identification of chromatin accessibility domains in human breast cancer stem cells

Epithelial-to-mesenchymal transition (EMT) is physiological in embryogenesis and wound healing but also associated with the formation of cancer stem cells (CSCs). Many EMT signaling pathways are implicated in CSC formation, but the precise underlying mechanisms of CSC formation remain elusive. We have previously demonstrated that PKC is critical for EMT induction and CSC formation in inducible breast EMT/CSC models. Here, we used formaldehyde-assisted isolation of regulatory elements-sequencing (FAIRE-seq) to investigate DNA accessibility changes after PKC activation and determine how they influence EMT and CSC formation. During EMT, DNA accessibility principally increased in regions distant from transcription start sites, low in CpG content, and enriched with chromatin enhancer marks. ChIP-sequencing revealed that a subset of these regions changed from poised to active enhancers upon stimulation, with some even more acteylated in CSCs. While regions with increased accessibility were enriched for FOX, AP-1, TEAD, and TFAP2 motifs, those containing FOX and AP-1 motif were associated with increased expression of CSC-associated genes, while those with TFAP2 were associated with genes with increased expression in non-CSCs. Silencing of 2 members of the FOX family, FOXN2 and FOXQ1, repressed CSCs and the mesenchymal phenotype and inhibited the CSC gene signature. These novel, PKC-induced DNA accessibility regions help explain how the epigenomic plasticity of cells undergoing EMT leads to CSC gene activation.

0.95 W high-repetition-rate, picosecond 335 nm laser based on a frequency quadrupled, diode-pumped Nd:YVO(4) MOPA system

An efficient all-solid-state picosecond (ps) ultraviolet (UV) laser at 335 nm was demonstrated based on frequency quadrupling of a mode-locked 1342 nm MOPA system. An output power of 0.95 W was obtained under a fundamental wave power of 16.38 W, corresponding to a conversion efficiency of 5.8% from infrared to UV. The repetition rate and pulse duration were 77 MHz and 20.2 ps, respectively. The beam quality factor M(2) was measured to be 1.56. This is, to the best of our knowledge, the highest output power at 335 nm.

Association of the IRF5 SNP rs2004640 with systemic sclerosis in Han Chinese

Systemic sclerosis (SSc) is a complex disease involving multiple genetic factors. An association of the IRF5 polymorphism with SSc was reported in Caucasian populations of Europe and North America, as well as in Japanese populations. The present study aimed to examine whether the SSc-associated SNP rs2004640 of IRF5 gene confer susceptibility to SSc and clinical features of SSc in a Han Chinese population. A Han Chinese cohort consisting of 424 SSc patients and 502 healthy controls were examined in the study. TaqMan assays were carried out to examine the SNP. Exact p-values were obtained (Fisher’s test) from 2x2 tables of allele counts and disease status. SSc patients of Han Chinese showed increased homozygous TT genotype of the rs2004640 (p = 0.027, odds ratio (OR) = 1.4, CI =1.03-1.93), which was significantly associated with pulmonary fibrosis of SSc and ATA-positive SSc of Han Chinese. The lcSSc and ACA-positive SSc of Han Chinese appeared also in association with the increased T allele frequency. However, the Chinese dcSSc did not show any association with the rs2004640. The results were consistent with previous reports in other ethnic populations in supporting the notion that polymorphisms of IRF5 may play an important role in susceptibility to SSc.

Serotonin in the ventral hippocampus modulates anxiety-like behavior during amphetamine withdrawal

Withdrawal from amphetamine is associated with increased anxiety and sensitivity to stressors which are thought to contribute to relapse. Rats undergoing amphetamine withdrawal fail to exhibit stress-induced increases in serotonin (5-HT) release in the ventral hippocampus and show heightened anxiety-like behaviors. Therefore, we tested the hypothesis that reducing 5-HT levels in the ventral hippocampus is a causal mechanism in increasing anxiety-like behaviors during amphetamine withdrawal. First, we tested whether reducing 5-HT levels in the ventral hippocampus directly increases anxiety behavior. Male rats were bilaterally infused with 5,7-dihydroxytryptamine (5,7-DHT) into the ventral hippocampus, which produced a 83% decrease in ventral hippocampus 5-HT content, and were tested on the elevated plus maze (EPM) for anxiety-like behavior. Reducing ventral hippocampus 5-HT levels decreased the time spent in the open arms of the maze, suggesting that diminished ventral hippocampus 5-HT levels increases anxiety-like behavior. Next, we tested whether increasing 5-HT levels in the ventral hippocampus reverses anxiety behavior exhibited by rats undergoing amphetamine withdrawal. Rats were treated daily with either amphetamine (2.5-mg/kg, i.p.) or saline for 2weeks, and at 2weeks withdrawal, were infused with the selective serotonin reuptake inhibitor paroxetine (0.5μM) bilaterally into the ventral hippocampus and tested for anxiety-like behavior on the EPM. Rats pre-treated with amphetamine exhibited increased anxiety-like behavior on the EPM. This effect was reversed by ventral hippocampus infusion of paroxetine. Our results suggest that 5-HT levels in the ventral hippocampus are critical for regulating anxiety behavior. Increasing 5-HT levels during withdrawal may be an effective strategy for reducing anxiety-induced drug relapse.

VNP: Interactive Visual Network Pharmacology of Diseases, Targets, and Drugs

In drug discovery, promiscuous targets, multifactorial diseases, and "dirty" drugs construct complex network relationships. Network pharmacology description and analysis not only give a systems-level understanding of drug action and disease complexity but can also help to improve the efficiency of target selection and drug design. Visual network pharmacology (VNP) is developed to visualize network pharmacology of targets, diseases, and drugs with a graph network by using disease, target or drug names, chemical structures, or protein sequence. To our knowledge, VNP is the first free interactive VNP server that should be very helpful for systems pharmacology research. VNP is freely available at http://cadd.whu.edu.cn/ditad/vnpsearch.

The use of propensity scores in pharmacoepidemiologic research

PURPOSE

To describe the application of propensity score analysis in pharmacoepidemiologic research using a study comparing the renal effects of two commonly prescribed non-steroidal anti-inflammatory drugs (NSAIDs).

METHOD

Observational data were collected on the change in renal function, as measured by serum creatinine concentration, before and after use of two NSAIDs, Ibuprofen and Sulindac. To estimate the treatment effect of the different NSAIDs, we used the propensity score methodology to reduce the potential confounding effects caused by unbalanced covariates. After estimating the propensity scores (the probabilities of each patient being prescribed Sulindac) from a logistic regression model, we stratified the data based on sample quintiles of the propensity score distribution. The final estimate of the treatment effect was then obtained by averaging the treatment estimates from the stratified samples.

RESULTS

Initially, 23 covariates differed significantly between the two treatment groups. Using the propensity score methodology, we were able to balance the distributions of 16 covariates. The imbalances in the remaining seven covariates were also greatly reduced. Although the use of either drug resulted in a decrease in renal function, overall differences between them were not statistically significant with respect to their effect on creatinine concentrations based on the propensity score analysis.

CONCLUSION

Observational studies often produce treatment groups that are not directly comparable due to imbalances in covariate distributions between the treatment groups. Propensity score analysis provides a simple and effective way of controlling the effects of these covariates and obtaining a less biased estimate of the treatment effect. Copyright (c) 2000 John Wiley & Sons, Ltd.

Low-level persistence of human papillomavirus 16 DNA in a cohort of closely followed adolescent women

Most human papillomavirus (HPV) infections in young women become undetectable by standard assays after a few months. It is possible that many HPV infections do not actually clear, but persist at very low levels for years, becoming detected again later in life. The purpose of this study is to describe HPV 16 clearance, reappearance, and low-level persistence in a cohort of adolescent women. Adolescent women (N = 66), not vaccinated against HPV, were recruited from 1998 to 2008 into a longitudinal study. Self-collected vaginal samples were obtained quarterly and tested for HPV by Linear Array HPV Genotyping Test (LA-HPV). To explore low-level persistence, a type-specific nested PCR for HPV 16 (TSN-PCR-16) was developed. Women with HPV 16 detected by LA-HPV had their negative swabs retested with TSN-PCR-16. Forty-two participants with HPV 16, followed for a mean of 6.3 years, were analyzed. Using LA-HPV, the median duration of HPV 16 detection was 428 days (SD 852.5 days). TSN-PCR-16 detected HPV 16 during periods of LA-HPV non-detection in samples from many women. Using a combination of LA-HPV and TSN-PCR-16 results, the median duration of HPV 16 detection was 1,022.5 days (SD 943.7 days). The durations of detection differed significantly between the two methods (P = 0.0042) with a mean difference of 434.5 days. In adolescent females, duration of HPV 16 detection was significantly longer when TSN-PCR-16 was combined with LA-HPV. Some apparently cleared HPV 16 could be shown to persist at low levels using nested PCR.

Heparin and prednisone-associated priapism: two case reports

Priapism is a prolonged penile erection that is not associated with sexual stimulation. In this report, two patients who developed priapism 2-4 h after an oral prednisone and intravenous heparin infusion are described. Low-flow (ischaemic) priapism is usually associated with sickle cell disease, haemoglobinopathies, neoplastic syndrome, anticoagulant therapy (heparin and warfarin), psychotropic medication, sildenafil citrate (Viagra) or idiopathic causes. Here we report two cases of prolonged low-flow priapism induced by heparin and prednisone. Treatments were successfully conducted after the priapism, while the exact mechanism remains unclear.

Human papillomavirus detection and typing in thin prep cervical cytologic specimens comparing the Digene Hybrid Capture II Assay, the Roche Linear Array HPV Genotyping Assay, and the Kurabo GeneSquare Microarray Assay

Three methods for the detection of HPV DNA were compared in cervical cytologic specimens: the Digene Hybrid Capture II Assay (HC), the Roche Linear Array HPV Genotyping Assay (LA) and the Kurabo GeneSquare Microarray (GS). The main goals of the study were to correlate cytology with HPV detection and to determine agreement between assay pairs for HPV detection. Thin-prep Pap smears were performed and supernates were tested by HC, LA, and GS. For specimens reacting with the HPV 52/33/35/58 probe in the LA assay, type-specific PCR was performed for HPV types 52, 33, 35, or 58. Binomial proportions and kappa coefficients were calculated for agreement between assays. Cytology results and supernatant were available for 202 subjects. HPV detection increased with worsening cytologic abnormality in all three assays. For all cytologic groups, LA and GS detected more HPV (all and oncogenic) than HC. However, for detection of oncogenic HPV types represented in all three assays, differences between assays were less pronounced. The highest agreement was between LA and GS. In four of 12 specimens reacting with the HPV 52/33/35/58 probe in the LA assay but deemed HPV 52-LA-negative using an algorithm provided by the manufacturer, the presence of HPV 52 was confirmed using type-specific HPV 52 PCR. All four of these specimens were also GS-positive for HPV 52.

Human papillomavirus infection and its association with cervical dysplasia in Ecuadorian women attending a private cancer screening clinic

Women living in Latin American countries bear a disproportionate burden of cervical cancer, a condition caused by infection with the human papillomavirus (HPV). We performed a study in Santa Elena, Guayas (currently Santa Elena Province), Ecuador, to determine how often HPV could be detected in women attending a private cancer screening clinic. Participants underwent a Pap test, and vaginal and cervical swabs were performed for HPV testing by the polymerase chain reaction (PCR). Each participant completed a verbally administered survey. The mean age of 302 participants was 37.7 years (range 18 to 78 years). The majority of cervical and vaginal specimens contained sufficient DNA to perform PCR. Overall, 24.2% of the participants had either a cervical or vaginal swab that tested positive for HPV. In general, there was a good correlation between the HPV types detected in the cervical and vaginal swabs from the participants, but vaginal swabs were more likely to contain HPV DNA than were cervical swabs. The high-risk HPV types 16, 52, 58, and 59 and the low-risk HPV types 62, 71, 72, and 83 were the most frequently detected HPV types. The number of lifetime sexual partners was positively associated with detection of any HPV type, detection of oncogenic HPV, and abnormal Pap smears. Further studies are needed to determine if these results are representative of all Ecuadorian women and to determine if cervical cancers in Ecuadorian women are caused by the same HPV types found in the swab specimens obtained in this study.

Factors associated with exacerbation of heart failure include treatment adherence and health literacy skills

We determined the factors associated with exacerbation of heart failure, using a cohort (n = 192) nested within a randomized trial at a university-affiliated ambulatory practice. Factors associated with emergency or hospital care included left ventricular ejection fraction, hematocrit and serum sodium levels, refill adherence, and the ability to read a prescription label. Refill adherence of <40% was associated with a threefold higher incidence of hospitalization for heart failure than a refill adherence of >or=80% (P = 0.002). In multivariable analysis, prescription label reading skills were associated with a lower incidence of heart failure-specific emergency care (incidence rate ratio, 0.76; 95% confidence interval (CI), 0.19-0.69), and participants with adequate health literacy had a lower risk of hospitalization for heart failure (incidence rate ratio, 0.34; 95% CI, 0.15-0.76). We conclude that inadequate treatment adherence and health literacy skills are key factors in the exacerbation of heart failure. These findings emphasize the need for careful instruction of patients about their medications.

The psychosocial impact of serological diagnosis of asymptomatic herpes simplex virus type 2 infection

OBJECTIVES

To evaluate the impact of a positive herpes simplex virus type 2 (HSV-2) serological test on psychosocial functioning among people with no known history of genital herpes.

METHODS

Individuals (age 14-30 years) without a history of genital herpes were recruited from an urban university setting and sexually transmitted diseases (STD), primary care, and adolescent clinics. Participants completed a questionnaire addressing psychological functioning, psychosocial adjustment, and perceived quality of sex and were offered free HSV-2 antibody testing. 33 HSV-2 positive people and 60 HSV-2 negative people demographically matched from the same source of recruitment were re-evaluated at a 3 month follow up visit. HSV-2 positive participants also completed a genital herpes quality of life (GHQOL) measure.

RESULTS

Of the 33 who were HSV-2 seropositive, four did not recall their diagnosis. In comparing those who were HSV-2 positive with those who were negative, repeated measures analysis of variance indicated there were no significant differences over time on any of the measures. None the less, many HSV-2 positive individuals indicated that the diagnosis had a notable impact on their quality of life. Also, among the HSV-2 positive people, lower GHQOL at the 3 month follow up was predicted by higher interpersonal sensitivity (r = -0.44, p<0.05), lower social support (r = 0.40, p<0.05), and quality of sex (r = 0.62, p<0.01) at baseline.

CONCLUSIONS

A diagnosis of asymptomatic HSV-2 infection does not appear to cause significant lasting psychological difficulties. Those for whom the diagnosis had the greatest impact were interpersonally vulnerable before the diagnosis. These results suggest that assessment of interpersonal distress may be important to include as part of pretest and post-test counselling.

Gender differences in sexual behaviours in response to genitourinary symptoms

OBJECTIVE

To understand gender differences in sexual behaviours in response to genitourinary symptoms.

METHODS

473 (239 female and 234 male) subjects were enrolled at an STD clinic regardless of symptoms or infection status. Subjects completed a 30 day calendar recall interview of genitourinary symptoms, coital activity, sexual partners, and condom use.

RESULTS

Of the total of 473 participants, 261 (55%) reported symptoms (61% women and 39% men). STI prevalence was 73% and 75% for symptomatic women and men, respectively. For black women the probability of coitus was decreased in the presence of vaginal discharge (OR 0.64, 95% CI 0.47 to 0.89). No change in coital activity was seen in non-black women in the presence of vaginal discharge. Having vaginal discharge did increase the likelihood of condom use by their partners (OR 2.48, 95% CI 1.05 to 5.88), if coitus occurred. Urethral discharge was not associated with coitus or condom use in men. However, in men, dysuria was associated with increased likelihood of condom use (OR 4.25, 95% CI 1.57 to 11.56) if coitus occurred.

CONCLUSION

Black women altered both coital activity and condom use behaviours in response to vaginal discharge. In contrast, non-black women did not modify coital activity. Men increased condom use when having dysuria but did not alter coital activity. Changes in sexual behaviours may alter the risk of STI transmission independent of interactions with the healthcare system. STI education and prevention programmes need to better understand these gender and racial differences in developing effective strategies to reduce STI transmission.

The combination of X-ray-mediated radiosurgery and gene-mediated immunoprophylaxis for advanced intracerebral gliosarcomas in rats

Rats with advanced, imminently lethal, approximately 4 mm diameter, left-sided intracerebral 9L gliosarcoma (9LGS), a well characterized malignant tumor with some similarities to human high-grade astrocytomas, were used as a therapy model 14 days post-implantation of 10(4) cells. Such tumor-bearing rats die within two weeks (median, 6 days) thereafter if untreated. However, if these tumors are exposed on day 14 to 12-25 Gy of an electron-equilibrated 6 MV photon beam (radiosurgery), survival is extended about 5-6 fold to a median of 34 days, but long-term survival (> 1 year) is increased only to approximately 18%. Multiple subcutaneous inoculations of radiation-disabled 9LGS cells post-radiosurgery (immunoprophylaxis) extended lifespan and long-term (> 1 year) survival minimally (median, 37 days; 25%, respectively). In sharp contrast, radiosurgery followed by multiple subcutaneous inoculations of radiation-disabled 9LGS cells that had been transfected with granulocyte macrophage colony stimulating factor (GMCSF), a cytokine with demonstrated immune-enhancing properties (i.e. gene-mediated immunoprophylaxis, GMIMPR) increased long-term survival to approximately 67%. To our knowledge, these results are the first to show that the combination of photon radiosurgery and GMIMPR is effective for an advanced, imminently lethal brain tumor in a mammal. These data raise the possibility that GMIMPR following radiation therapy might prove effective for the treatment of some human malignant gliomas.

Sexual behavior among adolescent women at high risk for sexually transmitted infections

BACKGROUND

The temporal pattern of partners and sexual encounters may be key factors in the acquisition and transmission of sexually transmitted diseases (STDs). Behavior among adolescent women is of particular interest because they frequently have the highest prevalence and incidence of infection.

GOAL

To examine coital diary data collected during a 7-month longitudinal study of young women at high risk of STDs and to describe their sexual behaviors, with particular attention to issues of partner sequence and overlap.

STUDY DESIGN

A 7-month longitudinal study of young women infected with or having a sexual contact infected with Neisseria gonorrhoeae, Chlamydia trachomatis, or Trichomonas vaginalis attending the STD clinic or one of four neighborhood adolescent health clinics. Data were collected at enrollment and at 1, 3, 5, and 7-month follow-up visits. Coital diaries were kept between visits.

RESULTS

The average frequency of coital events was 0.94 per week. The median number of sexual partners during the follow-up period was one, and overlapping of partnerships was an uncommon occurrence. The number of days between the last coital event of a current relationship and the first encounter of a new relationship differed for those choosing a new partner (mean, 20.6 days) and those who returned to a previous partner (mean, 7.9 days; P < 0.001).

CONCLUSION

Although at high risk for STDs, high-risk behavior was not common among the study population. Partner choice and the behavior of these partners may be more important elements than personal high-risk behavior in accounting for the high prevalence of sexually transmitted infections among inner-city adolescent women.

[Effects of quinacrine on gut-origin bacteria/endotoxin translocation in rats with gut ischemia/reperfusion injury]

OBJECTIVE

To explore the influence of quinacrine, which is an inhibitor of phospholipase A2, on gut-origin bacteria/endotoxin translocation in rats with gut ischemia/reperfusion injury.

METHODS

Forty-two Wistar rats were randomly divided into normal control (C, n = 6), gut ischemia/reperfusion injury control (IC, n = 12), quinacrine use at 3 hours after the injury(3 h, n = 12), and quinacrine use at 12 hours after the injury (12 h, n = 12) groups. The contents of blood endotoxin and TNF alpha in venae cavae and portal vein were measured in all groups. At the same time, tissue samples from mesenteric lymph nodes, liver, lungs and kidneys were harvested for bacterial culture.

RESULTS

Plasma contents of endotoxin and TNF alpha were lowered in both quinacrine treatment groups (P < 0.01). The incidence of bacterial/endotoxin translocation was decreased by quinacrine use in mesenteric lymph nodes, lungs, liver and kidneys after the injury (P < 0.05 approximately 0.01).

CONCLUSION

Early application of quinacrine in Wistar rats inflicted by gut ischemia reperfusion injury could obviously lower bacterial/endotoxin translocation and ameliorate the release of pro-inflammatory mediators and cytokines, thus attenuating injury to remote organs.

Changes of CD14 and CD1a expression in response to IL-4 and granulocyte-macrophage colony-stimulating factor are different in cord blood and adult blood monocytes

Neonates are relatively immature in their immune response; thus, to further clarify the differences of monocyte function and differentiation between neonates and adults, we investigated their CD14(+)CD4(+) and CD14(+)CD16(+) monocyte subpopulations, production of IL-1beta and tumor necrosis factor-alpha induced by lipopolysaccharide, and their CD14 and CD1a phenotypic changes in response to IL-4 and granulocyte-macrophage colony-stimulating factor. Our results showed that 1) the expression of CD14 in cord blood monocytes was significantly lower than that in adult peripheral blood monocytes; 2) both the percentages of CD14(+)CD4(+) cells and CD14(+)CD16(+) cells among CD14(+) monocytes were also significantly lower in cord blood; 3) after stimulation by lipopolysaccharide for 72 h, production of both IL-1beta and tumor necrosis factor-alpha was lower in cord blood than that in adult peripheral blood; and 4) in response to IL-4 or GM-CSF, the phenotype development of CD14 and CD1a in cord blood and adult peripheral blood was different. Down-regulation of CD14 expression in response to IL-4 and GM-CSF was slower in cord blood monocytes than that in adult peripheral blood monocytes. After 9 d of culture in the presence of IL-4 and GM-CSF, the percentage of CD1a(+) monocytes was significantly more increased in cord blood than that in adult peripheral blood. The reduced expression of CD14 and other mature phenotype markers such as CD16 and CD4 as well as the reduced IL-1beta and tumor necrosis factor-alpha production may contribute to the impaired immune response of neonates. Slower down-regulation of CD14 by IL-4 and GM-CSF suggests that differential properties of cord blood monocytes in response to cellular stress signals take a longer time than those of adult peripheral blood monocytes.

Downregulation of free ubiquitin: a novel mechanism of p53 stabilization and neuronal cell death

Neuronal death through activation of the p53 stress response pathway has been implicated in the pathogenesis of neurodegenerative disorders. The mechanisms regulating p53 accumulation and function in neurons are poorly understood. Recent evidence has demonstrated that Mdm2 is a major inhibitor of p53 that binds to and targets p53 for ubiquitin-mediated degradation. Here we demonstrate increased expression and co-localization of p53 and Mdm2 in the nuclei of degenerating neurons following treatment with either the excitotoxin, kainic acid, or the topoisomerase I inhibitor, camptothecin. Co-immunoprecipitation studies showed that p53-Mdm2 complexes were present in neuronal lysates. Dual immunofluorescence microscopy demonstrated that these complexes accumulated in neurons with a striking decrease in free ubiquitin levels. Exogenous ubiquitin restored p53 degradation to extracts from injured neurons confirming that Mdm2 function was intact. Finally, antisense-mediated downregulation of ubiquitin in cultured hippocampal neurons resulted in p53 and Mdm2 accumulation as well as apoptotic death. These results point to a novel mechanism to stabilize p53 and promote neuronal cell death in the central nervous system.

FK506, but not cyclosporin A, prevents mitochondrial dysfunction during hypoxia in rat hepatocytes

Hepatic ischemia/reperfusion injury occurs in the clinical situations including liver transplantation. FK506 and cyclosporin A (CsA) are reported to be hepatotrophic agents in addition to being a powerful immunosuppressive agent. Studies were performed to determine whether the drugs influence a mitochondrial dysfunction under the hypoxic conditions in primary culture model of rat hepatocytes. The Anaeropack system was used for cell culture to create a hypoxia. Cells were treated with FK506 or CsA under the normoxic and hypoxic conditions. Hypoxia markedly decreased intracellular adenosine 5'-triphosphate (ATP) contents and the ketone body ratio (KBR, acetoacetate/beta-hydroxybutyrate) in culture medium as compared with normoxia. FK506 prevented the decreases of ATP contents and the KBR. In contrast, CsA had no effect on either ATP contents or the KBR. FK506, but not CsA, increased the KBR under the normoxic conditions. Under the hypoxic conditions, heat shock protein 70 (Hsp70) was detected after reoxygenation. FK506 enhanced the induction of Hsp70, but CsA again had no effect on Hsp70 induction. These results indicate that FK506 protects the hypoxia injury in part by preventing the mitochondrial dysfunction in concert with the enhancement of heat shock response in hepatocytes.

Decreased yield, phenotypic expression and function of immature monocyte-derived dendritic cells in cord blood

Dendritic cells are critical for the induction of both primary immune responses and immunological tolerance, as well as for the regulation of T-helper 1 (Th1) and 2 (Th2) immune responses. As neonates are notably deficient in Th1 response and cord blood transplantation is noted to result in less graft-versus-host disease (GvHD), we compared the phenotypic and functional characteristics of monocyte-derived dendritic cells (DCs) that favour Th1 development from cord blood and adult peripheral blood to understand the underlying mechanisms of these observations. Our results showed that: (1) after culture for 7 d with interleukin (IL)-4 and granulocyte--macrophage colony-stimulating factor (GM-CSF), cord blood monocytes generated less CD1a(+) cells than adult peripheral blood monocytes, and the CD1a+ cell percentage decreased thereafter; (2) compared with adult blood DCs, cord blood DCs had reduced intensity of expression of CD1a and MHC class II molecules, but the expression levels of CD11c and CD86 were similar; (3) the endocytotic ability of cord blood DCs was reduced compared with adult blood DCs, and this function was related to reduced mannose receptor (MR)-positive cells; (4) furthermore, the ability of cord blood DCs to stimulate CD3(+) T cells in an allogeneic mixed lymphocyte reaction was significantly lower than that of adult blood DCs. These results suggested that the dysfunction of cord blood monocytes in differentiating into professional DCs will affect the activation of naive T cells, especially Th1 development, and may be related to the susceptibility to different infections in the neonates, as well as the lower incidence of GvHD in cord blood transplantation.

Long-term immunological memory in the resistance of rats to transplanted intracerebral 9L gliosarcoma (9LGS) following subcutaneous immunization with 9LGS cells

Glioblastoma multiforme (GBM) is the most common primary human brain tumor. About 7000 new cases are diagnosed yearly in the USA. Despite current neurosurgical and postoperative radiotherapeutic tumor cytoreduction methods, in most cases occult foci of tumor cells infiltrate surrounding edematous brain tissues and cause recurrent disease within one year. GBM is almost invariably fatal within a few years after it is diagnosed. Our goal is to achieve long-term control of GBM by combining immunoprophylaxis with a radiation-based technique, such as boron neutron-capture therapy (BNCT), potentially capable of specifically targeting the infiltrating tumor cells while sparing the surrounding normal brain tissue. It has long been known that the subcutaneous (sc) injection of irradiated cells or untreated cultured cells (and the removal of the resulting tumors) derived from the well characterized, highly immunogenic 9L gliosarcoma (9LGS) rat model into young isogenic rats can prevent tumor growth after subsequent sc or intracranial (ic) injection of untreated, otherwise lethal 9LGS cells. In this study we have confirmed, quantified and extended those findings to study the efficacy of such immunological memory in normal aging rats and in aging rats previously treated for ic 9LGS tumors by BNCT. (1) The sc injection of 5,000,000 untreated 9LGS cells and the surgical removal of the resulting tumors (method A) protected 80% of normal young rats from an ic challenge with 10,000 untreated 9LGS cells, and a single sc injection of 5,000,000 lethally X-irradiated 9LGS cells (method B) protected 66% of them, but multiple sc injections with a crude particulate fraction prepared from 9LGS cells were not protective. Protection is long-lasting since contralateral ic rechallenge of six-month survivors with an injection of 10,000 viable 9LGS cells resulted in 100% survival. (2) Normal one-year-old rats were only slightly less protected than were normal young rats, approximately 70% rather than approximately 80% (method A) and approximately 60% rather than approximately 66% (method B). (3) BNCT treatment alone resulted in partial immunological protection, as 30% of one-year post-BNCT survivors of ic 9LGS tumors prevailed after contralateral ic rechallenge with 10,000 viable 9LGS cells. Moreover a single sc immunization with 5,000,000 untreated 9LGS cells prior to ic rechallenge boosted survival from 30% to 100%. The relevance of these observations to strategies of preclinical experimentation for immunoprophylaxis of malignant gliomas is discussed.