Epidermal growth factor receptor (EGFR) mutation rate in advanced ovarian cancer (AOC): Results of a prospective study in Caucasian patients (pts)

13127

Background: The EGFR is over expressed in 55% to 98% of advanced epithelial ovarian carcinoma. Different studies demonstrated EGFR status as an independent prognostic factor for OC. Recent studies in non small cell lung cancer suggest that the presence of the clinical response to tyrosine kinase inhibitors (e.g. ZD 1839) correlates with the somatic mutations in the kinase domain of EGFR, exons 18–21. For pts with OC data are not available on EGFR gene mutation. Methods: Shock-frozen samples from 32 patients (pts) with primary of ovarian cancer were stratified in two groups according to disease-free interval: ≤6 months (17 pts.) and <6 months (15 pts.). All pts were prospectively collected within Tumor bank Ovarian Cancer Project. Patient collective consisted only from west European Caucasian women. Additionally, 9 commercial available ovarian cancer cell lines (TOV-90, TOV-112D, TOV-21G, OVCAR-3, A2780, A2780 ADR, ES-2, SK-OV-3, and Caov-3) and 32 established ovarian cancer lines were analysed. Exon sequencing of genomic DNA was used to detect L858R deletion mutations of EGFR within exons 21 of the kinase domain. PCR and capillary electrophoresis (Chip-Format) were used to analyse 15 bp deletion in Exon 19. We focused on descriptive analysis. The Log-Rank test was applied to confirm statistically significance (p-value of <0.05). Results: Overall, 74.6% of the pts. were diagnosed FIGO stage III-IV. Median follow-up period was: 14.17 month (range: 2–42 months). Whether in cell lines, nor in tumor samples, stratified to response of platinum therapy any mutation of EGFR gene was observed. Conclusions: Our study indicates that the prevalence of mutation in the kinase domain of EGFR, exons 19 and 21 seems to be very low in pts. with AOC. Further studies should investigate other ethical groups of pts.

No significant financial relationships to disclose.

Effects of polymorphism (plm) in interleukin (IL) 1 and IL10 genes on surgery outcome in ovarian cancer (OC)

20094

Background: IL1 and IL10 are overexpressed in 55% to 98% of advanced epithelial OC. Different studies demonstrated IL1 and IL10 as independent prognostic factors for OC. This study was performed to investigate the influence of plms of IL-1A, IL-1B and IL-10 gene on the occurrence tumor biology of OC. Methods: In a prospective, monocentric, case-control study 147 pts with OC (71 pts with primary OC and 77 pts with recurrent OC) and 129 pts with no history of malignancies were genotyped for plms of the IL-1 gene (IL-1A -889 T/C and IL-1B -511 C/T promoter) and IL-10 gene (IL-10 -1082 G/A, -819 C/T and -592 C/A). All pts were collected within Tumor bank Ovarian Cancer Project. Genomic DNA fragments were amplified by PCR and the allele sequences were obtained by pyrosequencing. We analyzed significance using the Chi-Square by Pearson and Fisher’s exact test. Statistical significance was determined by Mann-Whitney test. A two-tailed p value <0.05 was considered statistically significant. Overall survival (OS) was estimated using the Kaplan-Meier product limited method. Results: The median age of the pts with OC was 55.5 years (range 19–81 y). Median follow-up period was: 31.5 months (range: 1–225 mo). There were no significant associations between allelic frequencies for IL-1A and IL-1B in OC. The IL-10 plm in -819 and -592 positions significantly correlates with the postoperative residual tumor (p = 0.036 and p = 0.035 respectively). For pts without any postoperative tumor residuals the most encountered genotype was C/C at −819 and −592. The same genotype was associated in univariate analysis with a better OS (95% CI = 37.5–94.5 and 40.8–91.2, respectively). In the multivariate models there was no correlation between any plms and disease-free and OS. Postoperative residual tumor (OR =0.202, 95% CI = 0.088–0.462, p = 0.0001) and ascites volume (OR = 0.106, 95% CI = 0.046–0.248, p = 0.026) were independent prognostic factors for reduced OS. Conclusions: Plm of IL1A, IL1B, IL10 showed no association with occurrence of OC. IL-10 promoter plm may influence the tumor biology and could potentially predict results of radical surgery.

No significant financial relationships to disclose.

Active c-Src has prognostic and therapeutic value in ER-negative breast cancer

10063

Background: Approximately 33% of newly diagnosed breast cancers lack ER and these tend to have a worse prognosis as compared to ER-positive breast cancers. Therapeutic options are limited as they are not responsive to antihormonal therapy and often develop resistance to chemotherapies. We have recently shown that activation of the nonreceptor tyrosine kinase protein c-Src leads to the accelerated ER degradation in ER-negative breast cancers. This study performs an immunohistochemical analysis of activated c-Src in a large cohort of primary human breast carcinomas to a) assess its prognostic significance and b) correlate its relationship to the ER status of breast cancers. Methods: A total of 916 patients with breast cancer diagnosed between 1987 and 1997 had clinicopathological data and paraffin-embedded tumor tissues for the study. Tissue microarrays were constructed. A four point scoring system based on immunostaining intensity was used to grade the levels of active phosphorylated c-Src. Grading was done by one pathologist. Statistical analysis was used to assess the prognostic significance of activated c-Src and its relationship to other prognostic variables. Results: Median follow-up was 7.31 years. Active c-Src grade was inversely correlated with ER status (p=0.004) and predicted for treatment with chemotherapy (p=0.002) and lack of treatment with Tamoxifen (p=0.007). Patients with greater levels of c-Src tended to be younger (p=0.004) and had higher Bloom Richardson scores for their tumors (p=0.004). Higher levels of c-Src also predicted for for shorter timing to distant recurrence (p=0.01) and shorter timing to death (p=0.04). There was a trend towards a shorter timing to regional recurrence with higher levels of c-Src but the relationship was not statistically significant (p=0.08). Conclusion: This study supports the hypothesis that the presence of active, phosphorylated c-Src contributes to the development of ER-negative status in breast cancers. The presence of c-Src also is associated with other poor prognostic factors and contributes to a worse prognostic outcome. This study suggests that c-Src inhibitors may be a novel therapeutic strategy for the treatment of ER-negative breast cancers.

No significant financial relationships to disclose.

A proteomic analysis reveals the loss of expression of the cell death regulatory gene GRIM-19 in human renal cell carcinomas

Gene associated with retinoid interferon-induced mortality (GRIM)-19, an inhibitor of transcription factor STAT3, was originally identified as a critical regulatory protein in a genetic screen that was designed to identify the gene products necessary for Interferon (IFN)-beta- and retinoic acid-induced cell death. Over expression of GRIM-19 activates cell death. Conversely, inactivation of its expression promotes cell growth. STAT3 is a transcription factor that regulates gene expression in response to multiple extra cellular growth factors. In contrast to its normal feedback inhibition, a constitutive activation of STAT3 has been documented in several tumors. Although many STAT3-inhibitors are described, their relevance to human cancer is unclear. In an attempt to define the molecular alterations associated with human renal cell carcinoma (RCC) using mass spectrometry, we have discovered that expression of GRIM-19 is lost or severely depressed in a number of primary RCC and in some urinogenital tumors. Using an RCC cell line, we show that down regulation of GRIM-19 promotes tumor growth via an augmentation of STAT3-dependent gene expression. These studies for the first time show a tumor-suppressor like activity of GRIM-19.

Cancer risks in first degree relatives of BRCA1 mutation carriers: effects of mutation and proband disease status

BACKGROUND

Mutations in the BRCA1 (MIM 113705) gene are found in many families with multiple cases of breast and ovarian cancer, and women with a BRCA1 mutation are at significantly higher risk of developing breast and ovarian cancer than are the general public.

METHODS

We obtained blood samples and pedigree information from 3568 unselected cases of early-onset breast cancer and 609 unselected patients with ovarian cancer from hospitals throughout Poland. Genetic testing was performed for three founder BRCA1 mutations. We also calculated the risk of breast and ovarian cancer to age 75 in the first degree relatives of carriers using Kaplan-Meier methods.

RESULTS

The three founder BRCA1 mutations were identified in 273 samples (187 with 5382insC, 22 with 4153delA, and 64 with C61G). A mutation was present in 4.3% of patients with breast cancer and 12.3% of patients with ovarian cancer. The overall risk of breast cancer to age 75 in relatives was 33% and the risk of ovarian cancer was 15%. The risk for breast cancer was 42% higher among first degree relatives of carriers of the C61G missense mutation compared to other mutations (HR = 1.42; p = 0.10) and the risk for ovarian cancer was lower than average (OR = 0.26; p = 0.03). Relatives of women diagnosed with breast cancer had a higher risk of breast cancer than relatives of women diagnosed with ovarian cancer (OR = 1.7; p = 0.03).

CONCLUSIONS

The risk of breast cancer in female relatives of women with a BRCA1 mutation depends on whether the proband was diagnosed with breast or ovarian cancer.

[Study on the selection of crude drugs of rhubarb dispensing granule]

OBJECTIVE

To research and choose the best crude drugs of Rhubarb dispensing granule.

METHODS

According to standard method from the eighth edition of China pharmacopoeia, determined and compared the contents of TLC, water, total ash, acid insoluble ash, extractives, total anthraquinones, rhein, emodin and chrysophanol of Rhubarb in diffrent producing areas and species.

RESULTS

The Contents of Rheum palmatum from Rhubarb GAP base in Ganzhi state were higher than others and the drug yield was large.

CONCLUSION

This species are chosen to be the crude drugs for Rhubarb dispensing granule. The preliminary study provides the scientific grounds for next study about establishment of quality criteria.

Expression of estrogen receptor-related receptor isoforms and clinical significance in endometrial adenocarcinoma

Estrogen receptor-related receptors (ERRs) are members of orphan nuclear receptors closely related to the estrogen receptors (ERs). Researches showed that the ERRs bound to estrogen response elements and interfered in the ER signal pathway. Therefore, it might be associated with estrogen-dependent diseases. The purpose of this study was to explore whether ERRs were involved in the tumorigenesis of endometrial adenocarcinoma. We examined the expression of ERRs in endometrial adenocarcinoma and normal endometrium using semiquantitative reverse transcription-polymerase chain reaction and immunohistochemistry. Clinicopathologic features including FIGO stage, histologic grade, myometrial invasion, and nodal metastasis were reviewed. Results showed that messenger RNA (mRNA) levels of ERRalpha, ERRbeta, and ERRgamma were positively associated with the immunoreactivities (P= 0.009, P= 0.014, and P= 0.001, respectively). The expression rate and relative level of ERRalpha mRNA in ERalpha-positive endometrial adenocarcinomas were lower than in normal endometriums (P= 0.049 and P= 0.023), whereas the relative level of ERRgamma mRNA in ERalpha-positive endometrial adenocarcinomas was higher than in normal endometriums (P= 0.014). Expression of ERRalpha mRNA was positively correlated with FIGO stage (P= 0.019) and myometrial invasion (P= 0.043). A negative correlation was observed between expression of ERRgamma mRNA and nodal metastasis (P= 0.021). Results suggested that ERRalpha and ERRgamma might participate in the tumorigenesis of endometrial adenocarcinoma. ERRalpha and ERRgamma are promising to be new prognostic factors in endometrial adenocarcinoma.

Comorbid conditions in men with ED before and after ED diagnosis: a retrospective database study

Although erectile dysfunction (ED) has been considered a complication of other medical conditions, clinicians and researchers suggest that ED may serve as a clinical marker of vascular health. This retrospective claims study examined the prevalence of predefined comorbid conditions in men with ED (N=301 994) in the 12 months before and the 6 months following ED diagnosis. Consistent with previous research, comorbid conditions were prevalent among men with ED. Comorbid conditions were most often diagnosed before an ED diagnosis, although new diagnoses in the 6 months following an ED diagnosis were common and occured more frequently than new diagnoses in a matched sample of men without ED during the same period. Differences by age, region and insurance coverage for ED medications were also examined. Findings support previous research that suggests ED may serve as a marker for previously undetected comorbid conditions.

Neuroprotection and neurogenesis: Modulation of cornus ammonis 1 neuronal survival after transient forebrain ischemia by prior fimbria-fornix deafferentation

Severe transient forebrain ischemia causes selective neuronal death in the hippocampal cornus ammonis 1 region. We tested the hypothesis that fimbria-fornix deafferentation can provide long-term protection to cornus ammonis 1 neurons and modulate neurogenesis following ischemia. Fimbria-fornix lesion or sham-fimbria-fornix lesion was performed on Wistar rats 13 days prior to 10 min forebrain ischemia or sham ischemia. Temperature was regulated and rats survived for 7, 14 or 28 days. Immunofluorescent bromodeoxyuridine and neuron specific nuclear protein staining and immunochemistry terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining were performed. At 7 days after ischemia, 73%+/-14% of cornus ammonis 1 neurons were damaged, while deafferentation reduced the injury to 36%+/-17% of cornus ammonis 1 neurons. This protection persisted for at least 28 days. Ischemia significantly increased the number of bromodeoxyuridine-positive cells (85-90 cells/section in stroke group vs. 6 to 11 cells/section in normal or sham stroke group), with very few terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling-stained cells adjacent to the hippocampal cornus ammonis 1. Fimbria-fornix lesioning followed by ischemia increased the percentage of new neurons 13-fold over ischemia alone and 6.5-fold over sham lesion plus ischemia. The results indicate that fimbria-fornix deafferentation provides long-term neuroprotection in cornus ammonis 1 following forebrain ischemia and promotes neurogenesis after ischemic insults.

Contrast adaptation and representation in human early visual cortex

The human visual system can distinguish variations in image contrast over a much larger range than measurements of the static relationship between contrast and response in visual cortex would suggest. This discrepancy may be explained if adaptation serves to re-center contrast response functions around the ambient contrast, yet experiments on humans have yet to report such an effect. By using event-related fMRI and a data-driven analysis approach, we found that contrast response functions in V1, V2, and V3 shift to approximately center on the adapting contrast. Furthermore, we discovered that, unlike earlier areas, human V4 (hV4) responds positively to contrast changes, whether increments or decrements, suggesting that hV4 does not faithfully represent contrast, but instead responds to salient changes. These findings suggest that the visual system discounts slow uninformative changes in contrast with adaptation, yet remains exquisitely sensitive to changes that may signal important events in the environment.

A Web-based program for coding open-ended response protocols

A Web-based coding application was designed to improve coding efficiency and to provide a systematic means of evaluating responses to open-ended assessments. The system was developed for use by multiple raters to assign open-ended responses to predetermined categories. The application provides a software environment for efficiently supervising the work of coders and evaluating the quality of the coding by (1) systematically presenting open-ended responses to coders, (2) tracking each coder's categorized responses, and (3) assessing interrater consistency at any time in order to identify coders in need of further training. In addition, the application can be set to automatically assign repeated responses to categories previously identified as appropriate for those responses. To evaluate the efficacy of the coding application and to determine the statistical reliability of coding open-ended data within this application, we examined data from two empirical studies. The results demonstrated substantial interrater agreement on items assigned to various categories across free and controlled association tasks. Overall, this new coding application provides a feasible method of reliably coding open-ended data and makes the task of coding these data more manageable.

A comparative Langmuir-Blodgett study on a set of covalently linked porphyrin-based amphiphiles: a detailed atomic force microscopic study

A set of covalently linked phenyl-amidophenyl-substituted porphyrin amphiphiles with n-C15H31 tails have been synthesized and completely characterized. These amphiphiles form good Langmuir-Blodgett (LB) films at the air/water interface. Mean molecular areas for the series were measured from the isotherms and found to increase as the number of aliphatic chains increased from one to four. No influence of the subphase pH was observed on the isotherms. LB films can be transferred successfully onto different solid surfaces. The LB films were characterized using tapping mode atomic force microscopy (AFM). Bis-, tris-, and tetra-substituted porphyrins were found to be fairly good film-forming amphiphiles, whereas irregular aggregates were seen in the case of the monosubstituted porphyrin amphiphile. Multilayers were also formed with tetra-substituted amphiphiles on mica. Detailed AFM studies of tetra-substituted amphiphiles have been carried out to investigate the effect of preparation procedure and solid substrates on film formation and transfer. The absorption and fluorescence spectra for the amphiphiles in solution and LB films deposited onto mica and glass were recorded, which demonstrated the successful transfer of LB films onto the substrates and provided more information about the arrangement of porphyrin molecules within the LB films. For comparison, self-assembled monolayers (SAMs) and the cast thin films of the amphiphiles were prepared and characterized.

Biocomposite films synthesized at a fluid/fluid interface

In the synthesis of mesostructured particles and films, the cooperative self-organization of amphiphilic molecules in the presence of reactive species is a key factor in the reaction mechanism. This paper presents a method for preparing structured collagen films synthesized at fluid/fluid interfaces. This work is an extension of previous efforts in our group to synthesize structured silica films in a reaction system confined at the interface between two immiscible fluid phases, providing an additional level of control over the structural evolution that occurs during reaction. Synthesis at a liquid/liquid interface was shown to provide excellent control over the mesostructure of the final product, avoiding a major problem encountered in many film synthesis techniques in which the reaction occurs at a liquid/solid interface: namely, the undesired effect of the solid surface on the film structure. The focus of this paper is the synthesis of structured composite films containing amphiphilic phospholipids and collagen. These films provide a way to pattern cell growth on biocompatible surfaces and a model system for studying the self-assembly mechanism of lipids and collagen. Self-assembled monolayers and bilayers composed of phosphatidylethanolamine (PE) lipids and collagen were investigated to determine how regularly patterned films can be prepared in a manner that preserves the bioactive properties of the collagen. Mixtures of PEs and acid-soluble collagen were spread on an aqueous subphase in a Langmuir trough. Surface pressure-area compression isotherms for the composite lipid/collagen monolayers provide information about interactions between these components. Langmuir-Blodgett (LB) techniques were utilized to transfer the composite films onto freshly cleaved mica. The mica-supported films were characterized by atomic force microscopy. The lipid/collagen ratio in the composite films was found to be the most important factor in determining how the collagen is assembled and distributed. The temperature and pH of the aqueous subphase, the process for spreading collagen on the subphase, the deposition speed, and the deposition pressure are factors that can be used to selectively control the film patterning. For most of these experimental factors, the range over which a highly structured uniform film can be fabricated over significant length scales is generally very narrow. Based on the experimental results and understanding of the fundamental interactions involved, a mechanism for the co-self-assembly of phospholipids and collagen is suggested. The adhesion and growth of Chinese hamster ovary (CHO) cells on the patterned film surfaces demonstrates the biocompatibility of these composite films.

Population characteristics of traffic accident-related deaths in Japan and Ireland, 1950-2000

To compare epidemiological characteristics of traffic accidents in Japan and Ireland, we analyzed mortality and the negative effect on life expectancy between 1950 and 2000 and generated a multivariate model. The characteristics were similar in the two countries: The time trends showed an increase in mortality followed by a decrease. The mortality rates were about 13 and 5/100,000 for males and females, respectively, in 2000. Correlation coefficients for sex were over 0.9. Age distribution obeyed the natural logarithm regularity. The negative effect on life expectancy was about 0.34 year for males, and 0.13 year for females. The economic level was positively associated with mortality, whereas "number of vehicles owned" was associated negatively. In conclusion, we can take advantage of the broad consistencies in these two countries when we draw up an intervention strategy. Any preventive strategy should be directed to the young, particularly males.

Breast-feeding and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Several studies have reported that the risk of breast cancer decreases with increasing duration of breast-feeding. Whether breast-feeding is associated with a reduced risk of hereditary breast cancer in women who carry deleterious BRCA1 and BRCA2 mutations is currently unknown.

METHODS

We conducted a case-control study of women with deleterious mutations in either the BRCA1 or the BRCA2 gene. Study participants, drawn from an international cohort, were matched on the basis of BRCA mutation (BRCA1 [n = 685] or BRCA2 [n = 280]), year of birth (+/-2 years), and country of residence. The study involved 965 case subjects diagnosed with breast cancer and 965 control subjects who had no history of breast or ovarian cancer. Information on pregnancies and breast-feeding practices was derived from a questionnaire administered to the women during the course of genetic counseling. Conditional logistic regression analyses were used to estimate odds ratios (ORs) for the risk of breast cancer. All statistical tests were two-sided.

RESULTS

Among women with BRCA1 mutations, the mean total duration of breast-feeding was statistically significantly shorter for case subjects than for control subjects (6.0 versus 8.7 months, respectively; mean difference = 2.7 months, 95% confidence interval [CI] = 1.4 to 4.0; P<.001). The total duration of breast-feeding was associated with a reduced risk of breast cancer (for each month of breast-feeding, OR = 0.98, 95% CI = 0.97 to 0.99; P(trend)<.001). Women with BRCA1 mutations who breast-fed for more than 1 year were less likely to have breast cancer than those who never breast-fed (OR = 0.55, 95% CI = 0.38 to 0.80; P =.001), although no such association was seen for BRCA2 (OR = 0.95, 95% CI = 0.56 to 1.59; P =.83).

CONCLUSIONS

Women with deleterious BRCA1 mutations who breast-fed for a cumulative total of more than 1 year had a statistically significantly reduced risk of breast cancer.

Cloning of hypoxia-inducible factor 1alpha cDNA from a high hypoxia tolerant mammal-plateau pika (Ochotona curzoniae)

Hypoxia-inducible factor 1 is a transcription factor composed of HIF-1alpha and HIF-1beta. It plays an important role in the signal transduction of cell response to hypoxia. Plateau pika (Ochotona curzoniae) is a high hypoxia-tolerant and cold adaptation species living only at 3000-5000 m above sea level on the Qinghai-Tibet Plateau. In this study, HIF-1alpha cDNA of plateau pika was cloned and its expression in various tissues was studied. The results indicated that plateau pika HIF-1alpha cDNA was highly identical to those of the human (82%), bovine (89%), mouse (82%), and Norway rat (77%). The deduced amino acid sequence (822bp) showed 90%, 92%, 86%, and 86% identities with those of the human, bovine, house mouse, and Norway rat, respectively. Northern blot analyses detected two isoforms named pLHIF-1alpha and pSHIF-1alpha. The HIF-1alpha mRNA was highly expressed in the brain and kidney, and much less in the heart, lung, liver, muscle, and spleen, which was quite different from the expression pattern of mouse mRNA. Meanwhile, a new variant of plateau pika HIF-1alpha mRNA was identified by RT-PCR and characterized. The deduced protein, composed of 536 amino acids, lacks a part of the oxygen-dependent degradation domain (ODD), both transactivation domains (TADs), and the nuclear localization signal motif (NLS). Our results suggest that HIF-1alpha may play an important role in the pika's adaptation to hypoxia, especially in brain and kidney, and pika HIF-1alpha function pattern may be different from that of mouse HIF-1alpha. Furthermore, for the high ratio of HIF-1alpha homology among the animals, the HIF-1alpha gene may be a good phylogenetic performer in recovering the true phylogenetic relationships among taxa.

An improved morphological approach to background normalization of ECG signals

This paper describes an improved morphological approach to remove baseline wander from neonatal electrocardiogram (ECG) signals, with particular emphasis on preserving the ST segment of the original signal. The algorithm consists of two stages of morphological processing. First, the QRS complex and impulsive noise component due to skeletal muscle contractions etc., are detected and removed from the input signal. Second, the corrected QT interval (QTc) and RR interval are used to determine a structuring element. With this structuring element, the same morphological operation as in the first stage is then applied to the QRS-removed signal to obtain and remove the baseline wander. The performance of the algorithm is evaluated with simulated and real ECGs. Compared with an existing morphological method, there is a substantial improvement, especially in reducing distortion of the baseline waveform within the PR and QT intervals.

Letter recognition of Germans and Chinese - similarities in attention allocation and differences in encoding

Abstract. Germans and Chinese participated in letter recognition experiments based on the Sperling paradigm. They were instructed to report as many items as possible from a briefly exposed two-row matrix of letters from the Latin alphabet. In Experiment 1, the Germans performed better than the Chinese. In addition, a position effect was found in that participants correctly reported more letters from the first row than from the second row. In Experiment 2, the position effect was replicated even though the response mode prompted participants to report items from the bottom row first. In Experiment 3, the instruction as to how to allocate attention influenced the position effect. The performance lead of the Germans, as compared to the Chinese, was independent of these instructions. It is hypothesized that reading habits have influenced the allocation of attention and that language-specific encoding of the letters caused the differences in performance.

A colorimetric bead-binding assay for detection of intermolecular interactions

We have developed a new technique that rapidly and reproducibly allows direct visualization of molecular interactions, including receptor-ligand binding. The technique can be easily applied to examine binding between proteins and glycoproteins, or proteins and glycolipids, including gangliosides. In this novel bead-binding assay, the suspected 'ligand' molecule is bound to 0.2- or 1.0- micro m colored FluoSphere beads. These coated beads are then mixed directly with 150- micro m Sepharose or 50- to 75- micro m agarose beads coated with the second 'target' molecule. Binding between molecules is easily detected by immunofluoresence microscopy as colored rosettes or aggregations formed by clustering of the smaller fluorescent beads around the larger non-fluorescent bead. The validity of this technique for glycolipid binding to protein was verified through demonstration of the known interaction between the beta subunit of cholera toxin with ganglioside GM1. The bead-binding technique facilitated the novel observations of interaction between ganglioside GT1b with the alpha5 subunit of alpha5beta1 integrin and the interaction of GM3 with the epidermal growth factor receptor. A modification of this technique, in which the coated beads are bound to protein fixed on plates, allows a quantifiable colorimetric assay of interaction. This versatile and rapid technique will have widespread applications for in vitro systems and may also be useful for in vivo analysis of binding to cell surface receptor molecules.

Wavefront aberrations in eyes of emmetropic and moderately myopic school children and young adults

Wavefront aberrations were measured using a psychophysical ray-tracing technique in both eyes of 316 emmetropic and moderately myopic school children and young adults. Myopic subjects were found to have greater mean root mean square (RMS) value of wavefront aberrations than emmetropic subjects. Emmetropic adults had the smallest mean RMS, which remained smaller than the values for myopic adults and children and for emmetropic children both when second order Zernike aberrations (astigmatism) and third order Zernike aberrations were removed. Twenty percent of myopic adults had RMS values greater than values for all of the emmetropic adults, with significantly greater values for Zernike aberrations from second to seventh orders. High amounts of wavefront aberrations, which degrade the retinal image, may play a role in the development of myopia.

Transcriptional regulation of mouse delta-opioid receptor gene: role of Ets-1 in the transcriptional activation of mouse delta-opioid receptor gene

Previously, we identified a minimum core promoter of the mouse delta-opioid receptor (DOR) gene. The DOR promoter contains an E-box that binds upstream stimulatory factor and is crucial for the DOR promoter activity in NS20Y cells, a mouse neuronal cell line that constitutively expresses DOR. In the present study, we further analyzed the DOR promoter in NS20Y cells and have demonstrated that transcription factor Ets-1 binds to an Ets-1-binding site overlapping the E-box and trans-activates the DOR promoter by synergizing with upstream stimulatory factor in specific DNA binding. In addition, the Ets-1 DNA-binding domain is sufficient to play the functional role of Ets-1 in trans-activating the DOR promoter. Furthermore, through in vivo cross-linking assays and Northern blot analyses, we have demonstrated that Ets-1 binds to the DOR promoter in the neonatal mouse brain and that overexpressed Ets-1 can significantly enhance the expression of DOR mRNA in primary neonatal mouse neuronal cells. Collectively, our data suggest that Ets-1 functions as a trans-activator of the DOR promoter in the neonatal mouse brain and thus may contribute to the development of the mouse brain DOR system.

Inhibition of integrin-linked kinase/protein kinase B/Akt signaling: mechanism for ganglioside-induced apoptosis

Ganglioside GT1b inhibits keratinocyte attachment to and migration on a fibronectin matrix by binding to alpha(5)beta(1) and preventing alpha(5)beta(1) interaction with fibronectin. The role of gangliosides in triggering keratinocyte apoptosis, however, is unknown. Addition of GT1b to keratinocyte-derived SCC12 cells, grown in serum-free medium but exposed to fibronectin, suppressed Bad phosphorylation, activated caspase-9, and inhibited cyclin D and E expression, resulting in cell cycle arrest at G(1) phase and initiation of apoptosis. The mechanism of GT1b activation of caspase-9 involved inhibition of beta(1) integrin serine/threonine phosphorylation and decreased phosphorylation of both integrin-linked kinase and protein kinase B/Akt at its Ser-473 site, leading to cytochrome c release from mitochondria. Consistently, blockade of GT1b function with anti-GT1b antibody specifically activated the Ser-473 site of Akt, markedly suppressing apoptosis. The ganglioside-induced inhibition of Akt phosphorylation was GT1b-specific and was not observed when cells were treated with other keratinocyte gangliosides, including GD3. These studies suggest that the modulation of keratinocyte cell cycle and survival by GT1b is mediated by its direct interaction with alpha(5)beta(1) and resultant inhibition of the integrin/integrin-linked kinase/protein kinase B/Akt signaling pathway.

A new total synthesis of the marine tunicate alkaloid lepadiformine

[reaction: see text]. A total synthesis of racemic lepadiformine has been achieved via a route that utilizes as key steps a novel stereocontrolled intramolecular spirocyclization of an allylsilane/N-acyliminium ion and the application of our radical-based methodology for production of N-acylimines from o-aminobenzamides.

Fabrication of nanometer-sized electrodes and tips for scanning electrochemical microscopy

A novel method for fabrication of nanometer-sized electrodes and tips suitable for scanning electrochemical microscopy (SECM) is reported. A fine etched Pt wire is coated with polyimide, which was produced by polymerization on the Pt surface initiated by heat. This method can prepare electrodes with effective radii varying from a few to hundreds of nanometers. Scanning electron microscopy, cyclic voltammetry, and SECM were used to characterize these electrodes. Well-defined steady-state voltammograms could be obtained in aqueous or in 1,2-dichloroethane solutions. This method produced the nanoelectrodes with exposed Pt on the apex, and they can also be employed as the nanotips for SECM investigations. Different sizes of Pt nanotips made by this method were employed to evaluate the kinetics of the redox reaction of Ru(NH3)6(3+) on the surface of a large Pt electrode by SECM, and the standard rate constant kappa0 of this system was calculated from the best fit of the SECM approach curve. This result is similar to the values obtained by analysis of the obtained voltammetric data.

Adolescent smoking in Wuhan, China: baseline data from the Wuhan Smoking Prevention Trial

BACKGROUND

This study reports the prevalence of adolescent smoking in the urban and rural areas of Wuhan, China, the capital of Hubei Province, on the Yangtze River in central China.

METHODS

Smoking behavior was examined by age, gender, and urbanicity as part of the Wuhan Smoking Prevention Trial. Subjects included 6994 seventh- to ninth-grade students attending 22 randomly selected schools in urban and rural districts. Outcome measures included lifetime smoking, past-30-day smoking, established smoking (>100 cigarettes in lifetime), and susceptibility to smoking (absence of a firm commitment not to smoke).

RESULTS

Lifetime smoking prevalence was 47% among boys and 18% among girls. Past-30-day smoking prevalence was 16% among boys and 4% among girls. Established smoking prevalence was 2% among boys and 0% among girls. The prevalence of susceptibility to smoking was 31% among boys and 10% among girls. Smoking increased significantly with age (p<.0005). Susceptibility was more prevalent in rural areas than in urban areas (p<.05), but there were no urban-rural differences in lifetime, past 30-day smoking, or established smoking. Trend analyses revealed that smoking increased with age more rapidly among boys than among girls (p<.05). Smoking was more prevalent among rural boys than among urban boys, but it was more prevalent among urban girls than among rural girls (p<.05).

CONCLUSIONS

Adolescent smoking is a significant public health problem in China. Boys are at particularly high risk, as are girls living in urban areas. Effective smoking prevention programs for adolescents, as well as restrictions on tobacco industry marketing and youth access to tobacco, are needed to prevent tobacco-related morbidity and mortality in China.

Epidermal growth factor receptor glycosylation is required for ganglioside GM3 binding and GM3-mediated suppression [correction of suppresion] of activation

Gangliosides are able to bind to the epidermal growth factor receptor and inhibit its activation, but the mechanism of this inhibition is unknown. To address the role of receptor carbohydrates in facilitating interaction with gangliosides, we examined the ability of GM3 to bind the deglycosylated receptor and inhibit its autophosphorylation. Flow cytometry studies demonstrated that deglycosylation of the receptor did not affect its ability to be transported to the cell membrane. In contrast with the native (fully glycosylated) receptor, GM3 did not coimmunoprecipitate with the deglycosylated receptor. Using a novel colorimetric bead binding assay, GM3 was shown to bind well to the immunoprecipitated native receptor but not at all to the deglycosylated receptor. Finally, the addition of GM3 to cells with deglycosylated epidermal growth factor receptors did not result in significant further inhibition of autophosphorylation of the receptor, despite a 10-fold decrease in phosphorylation of the native epidermal growth factor receptor by 200 microM GM3. These studies suggest that ganglioside affects epidermal growth factor receptor activity through a direct interaction that requires receptor glycosylation, and contribute to our understanding of the role of gangliosides in cell membrane function.

Oxygenated carotenoid lutein and progression of early atherosclerosis: the Los Angeles atherosclerosis study

BACKGROUND

Carotenoids are hypothesized to explain some of the protective effects of fruit and vegetable intake on risk of cardiovascular disease. The present study assessed the protective effects of the oxygenated carotenoid lutein against early atherosclerosis.

METHODS AND RESULTS

EPIDEMIOLOGY

Progression of intima-media thickness (IMT) of the common carotid arteries over 18 months was determined ultrasonographically and was related to plasma lutein among a randomly sampled cohort of utility employees age 40 to 60 years (n=480). Coculture: The impact of lutein on monocyte response to artery wall cell modification of LDL was assessed in vitro by quantification of monocyte migration in a coculture model of human intima. Mouse models: The impact of lutein supplementation on atherosclerotic lesion formation was assessed in vivo by assigning apoE-null mice to chow or chow plus lutein (0.2% by weight) and LDL receptor-null mice to Western diet or Western diet plus lutein. IMT progression declined with increasing quintile of plasma lutein (P for trend=0.007, age-adjusted; P=0.0007, multivariate). Covariate-adjusted IMT progression (mean+/-SEM) was 0.021+/-0.005 mm in the lowest quintile of plasma lutein, whereas progression was blocked in the highest quintile (0.004+/-0.005 mm; P=0.01). In the coculture, pretreatment of cells with lutein inhibited LDL-induced migration in a dose-dependent manner (P<0.05). Finally, in the mouse models, lutein supplementation reduced lesion size 44% in apoE-null mice (P=0.009) and 43% in LDL receptor-null mice (P=0.02).

CONCLUSIONS

These epidemiological, in vitro, and mouse model findings support the hypothesis that increased dietary intake of lutein is protective against the development of early atherosclerosis.

Tubal ligation and risk of ovarian cancer in carriers of BRCA1 or BRCA2 mutations: a case-control study

BACKGROUND

In several case-control and prospective studies, tubal ligation has been associated with a decreased risk of invasive epithelial ovarian cancer. We aimed to assess the potential of tubal ligation in reducing the risk of ovarian cancer in women who carry predisposing mutations in the BRCA1 or BRCA2 genes.

METHODS

We did a matched case-control study among women from Canada, the USA, and the UK who had undergone genetic testing and who carried a pathogenic mutation in BRCA1 or BRCA2. Cases were 232 women with a history of invasive ovarian cancer, and controls were 232 women without ovarian cancer, and who had both ovaries intact. Cases and controls were matched for year of birth, country of residence, and mutation (BRCA1 or BRCA2). The odds ratio for developing ovarian cancer was estimated for tubal ligation, adjusting for oral contraceptive use, parity, history of breast cancer, and ethnic group.

FINDINGS

In an unadjusted analysis among BRCA1 carriers, significantly fewer cases than controls had ever had tubal ligation (30 of 173 [18%] vs 60 of 173 [35%], odds ratio 0.37 [95% CI 0.21-0.63]; p=0.0003). After adjustment for oral contraceptive use, parity, history of breast cancer and ethnic group, the odds ratio was 0.39 (p=0.002). Combination of tubal ligation and past use of an oral contraceptive was associated with an odds ratio of 0.28 (0.15-0.52). No protective effect of tubal ligation was seen among carriers of the BRCA2 mutation.

INTERPRETATION

Tubal ligation is a feasible option to reduce the risk of ovarian cancer in women with BRCA1 mutations who have completed childbearing.

Carbohydrate-carbohydrate binding of ganglioside to integrin alpha(5) modulates alpha(5)beta(1) function

Gangliosides GT1b and GD3, components of keratinocyte membranes, inhibit keratinocyte adhesion to fibronectin. Although ganglioside sialylation is known to be important, the mechanism of inhibition is unknown. Using purified insect recombinant alpha(5) and beta(1) proteins and alpha(5)beta(1) integrin from lysed keratinocyte-derived SCC12 cells, we have shown that GT1b and GD3 inhibit the binding of alpha(5)beta(1) to fibronectin. Co-immunoprecipitation of GT1b and alpha(5)beta(1) from SCC12 cells and direct binding of GT1b and GD3 to affinity-purified alpha(5)beta(1) from SCC12 cells and insect recombinant alpha(5)beta(1), particularly the alpha(5) subunit, further suggest interaction between ganglioside and alpha(5)beta(1). The carbohydrate moieties of integrin appear to be critical since gangliosides are unable to bind deglycosylated forms of alpha(5)beta(1) from SCC12 and insect cells or poorly glycosylated recombinant alpha(5)beta(1) from Escherichia coli cells. The GT1b-alpha(5)beta(1) interaction is inhibited by concanavalin A, suggesting that GT1b binds to mannose structures in alpha(5)beta(1). The preferential binding of GT1b to high mannose rather than reduced mannose ovalbumin further implicates the binding of GT1b to mannose structures. These data provide evidence that highly sialylated gangliosides regulate alpha(5)beta(1)-mediated adhesion of epithelial cells to fibronectin through carbohydrate-carbohydrate interactions between GT1b and the alpha(5) subunit of alpha(5)beta(1) integrin.

Dehydroepiandrosterone (DHEA) reduces neuronal injury in a rat model of global cerebral ischemia

INTRODUCTION

Many studies report an inverse correlation between levels of DHEA and neurological diseases. Exogenous DHEA protects hippocampal neurons against excitatory amino acid induced neurotoxicity. The purpose of this experiment is to evaluate the effect of DHEA in an animal model of transient but severe forebrain ischemia.

METHODS

At thirteen days prior to induction of ischemia, male Wistar rats were implanted with various doses of DHEA-placebo, 25 mg, 50 mg or 100 mg. Forebrain ischemia was induced for 10 min using a modified four-vessel occlusion technique, with hippocampal neuronal injury assessed at 7 days post-ischemically and expressed as a percentage of total cells.

RESULTS

Both normal and necrotic hippocampal CA(1) cells were counted. Percentages of hippocampal injury observed were 88+/-13% in animals treated with placebo, 84+/-8% in the 25 mg DHEA group, and 60+/-7% in the 50 mg DHEA group. Animals treated with 100 mg DHEA displayed a significant (P<0.05) reduction of hippocampal CA(1) cell injury at 60+/-7%

CONCLUSION

Treatment with a high dose, but not a low or moderate dose, of DHEA implantation reduces hippocampal CA(1) neuronal injury following severe but transient forebrain ischemia.

Ganglioside modulates ligand binding to the epidermal growth factor receptor

Whereas previous investigations have shown that pharmacologic addition of gangliosides inhibits keratinocyte proliferation by downregulating epidermal growth factor receptor phosphorylation, the underlying biochemical basis and physiologic relevance are unknown. Using Scatchard and displacement plots, we have shown that supplemental purified gangliosides decrease the binding of (125)I-labeled epidermal growth factor to keratinocyte-derived SCC12 cells. Conversely, SCC12 cells transfected with sialidase and thus depleted of gangliosides show increased ligand binding to the epidermal growth factor receptor, which is consistent with their increased proliferation in response to epidermal growth factor and transforming growth factor-alpha, and increased phosphorylation of the epidermal growth factor receptor, and downstream signal transduction pathway components. The mechanism of the altered binding appears to involve primarily decreased numbers of available receptors within the intact membrane, but not altered receptor protein expression. These studies provide evidence that the effect of gangliosides on keratinocyte proliferation results, at least in part, from the direct binding of ganglioside to the receptor and disruption of the receptor-ligand interaction. Manipulation of membrane ganglioside content may be a powerful new means to alter epidermal growth factor receptor-dependent cell proliferation.

Fetal neurosurgery

SURGERY BEFORE BIRTH has been performed for lethal conditions for several years. The techniques that have been developed are being applied to nonlethal conditions such as meningomyelocele. It is possible that fetal surgery might find a place in the management of certain forms of hydrocephalus as well. The challenge is to define which patients might benefit from such radical procedures before these techniques are accepted as standard care.

Light, Temperature, and Moisture Effects on Apothecium Production of Sclerotinia sclerotiorum

The purpose of this study was to quantify the effects of light, moisture, and temperature on apothecium production of Sclerotinia sclerotiorum. Sclerotia were placed in sand beds in crispers and exposed to two light intensities. For each light intensity, sclerotia were subjected to five temperature levels and three moisture levels. The results showed that the optimal temperature and temperature range for germination of sclerotia were affected by both light intensity and the moisture level of the sand. At light intensity of 80 to 90 mol m^-2 s^-1 (low light intensity treatment), the optimal temperatures were in the range of 12 to 18°C regardless of moisture level. At light intensity of 120 to 130 mol m^-2 s^-1 (high light intensity treatment), the optimal temperature was shifted to 20°C when the soil moisture level was high. Under high light intensity, only a few days were needed for initials to develop into apothecia. Under low light intensity, several weeks were needed for initials to develop into apothecia. The frequency with which initials developed into apothecia was high under high light intensity (80%) but low under low light intensity. The initials produced at low light intensity and high temperature (25 to 30°C) were thinner and longer. The apothecia also were smaller at low light intensity than those produced at high light intensity at any temperature. The periods for apothecium production were longer under lower temperature treatments. The relationship between apothecium production and degree days was analyzed. Apothecium production began at about 160 degree days and ceased at about 900 degree days at high light intensity. However, production began at about 760 degree days and ceased at 1,720 degree days at low light intensity. Nonlinear regression equations which describe the relationship between cumulative formation of apothecia and degree days were highly significant. The deviation between the observed value and the predicted value increased as degree days increased.

[Foundational study of subcritical water chromatography]

AIM

To study the subcritical water chromatographic discipline of compounds with medium and high polarity on the capillary and packed column.

METHODS

A packed and capillary subcritical water chromatography-FID detection system was built up. Six alcohols were well separated on a C18 column and the influence of temperature on chromatographic behavior of alcohols with different polarity was studied. The influence of temperature and pressure on chromatographic behavior of benzoic acid and gensenoside Rg1 on a SE-54 capillary column were also studied.

RESULTS

Increasing temperature resulted in the decreasing polarity of mobile phase, shortened retention times of components separated, narrowed peak shape and improved tailing as well.

CONCLUSION

Temperature programming could be used successfully to separate compounds with various polarity selectively. Thermostable capillary column could enlarge the range of temperature even more.

Periodic NADH oxidase activity associated with an endoplasmic reticulum fraction from pig liver. Response to micromolar concentrations of retinol

An endoplasmic reticulum fraction from pig liver enriched in transitional endoplasmic reticulum vesicles capable of forming 50-60 nm buds in the presence of ATP and retinol was assayed for retinol-responsive oxidation of NADH and cleavage of a dithiodipyridine (DTDP) protein disulfide-thiol interchange substrate. Maxima for the two activities alternated giving rise to a 24 min period. The NADH oxidase activity was inhibited by micromolar and submicromolar concentrations of retinol. Retinol at 0.1 mM stimulated the activity. The inhibition was confined to two activity maxima separated in time by about 5 min. In contrast, with the DTDP substrate, the activity was stimulated by retinol and the stimulations were in the part of the oscillatory pattern where retinol inhibition of NADH oxidation was observed. The findings support an earlier proposed mechanism whereby retinol exerted opposing effects on NADH oxidation and protein disulfide reductions.

CoQ10 fails to protect brain against focal and global ischemia in rats

OBJECTIVE

Release of oxygen free radicals occurs following cerebral ischemia. Studies show that oxygen free radicals mediate ischemic brain injury. CoQ10 is a potent free radical scavenger and may offset brain injury associated with reperfusion. We tested exogeneous CoQ10 as a neuroprotectant in rats following both global and focal ischemic insults.

METHODS

Rats were subjected to either 4-vessel occlusion ischemia (4-VO, 10 min occlusion, 7-day survival) or middle cerebral artery occlusion (MCAO, 120 min-occlusion, 22.5 h survival). Regional cerebral blood flows (rCBF) and physiological variables such as blood pressure, pO2, pCO2, plasma glucose and hematocrit were monitored and measured in focal ischemia. The animals were randomized to receive treatments of either phosphate buffered saline (PBS) vehicle or CoQ10 following global or focal ischemia. Injection times were at the end of ischemia and 3 h later for both models of ischemia. Histological outcomes are expressed as a percentage of hippocampal CA(1) cell injury in global ischemia or percentage of cortical infarct over that of non-ischemic hemisphere in focal ischemia.

RESULTS

In global ischemia, animals treated with PBS vehicle and CoQ10 had 86+/-5% (n=8) and 83+/-10% (n=8), respectively, of hippocampal CA(1) cell injury (P>0.05). The percentage of infarct volumes in animals following focal ischemia were 23+/-9% (control, n=10) and 25+/-9% (CoQ10, n=10). There were no temperature or physiological differences between the two treatment groups.

CONCLUSION

Acute treatment with CoQ10 via intraperitoneal injection does not prevent neuronal injuries following global and focal ischemia.

CHOP Infant Coma Scale ("Infant Face Scale"): a novel coma scale for children less than two years of age

The Glasgow Coma Scale (GCS) is the most frequently used tool worldwide for assessing the severity of neurologic injury after brain trauma, although applying this scale to infants and younger children can be problematic. The CHOP Infant Coma Scale, or Infant Face Scale (IFS), is a novel scale for children under 2 years of age which differs from other pediatric coma scales in the following ways: (1) it relies on objective behavioral observations; (2) it assesses cortical as well as brainstem function; (3) it parallels the GCS in scoring but is based on infant-appropriate behaviors; and (4) it can be applied to intubated patients. We report the results of a prospective study designed to compare interrater reliability between the IFS and GCS in children less than 2 years of age. Seventy-five hospitalized children less than 2 years of age were assessed simultaneously by a pair of observers, representing a spectrum of health care professionals, who scored the children using both the IFS and GCS. Interrater reliability for each pair of observers for each scale was assessed using the kappa statistic. A second series of 10 infants in the intensive care unit with specific diagnoses of acute traumatic or hypoxic/ischemic brain injury were similarly assessed. In the 75 hospitalized infants with a variety of diagnoses, interrater reliability for the GCS was in the "almost perfect," "slight," and "fair" range for the eye-opening, motor, and verbal subtests, respectively. In contrast, the IFS showed interrater reliability in the "almost perfect," "substantial," and "almost perfect" ranges for the three subtests. When applied to infants in an intensive care unit with acute traumatic brain injury or hypoxia/ischemia, the GCS interrater reliability scores were in the "fair" range, while the IFS scores were in the "almost perfect" range. The IFS demonstrates improved interrater reliability in direct comparison to the GCS, particularly in the "verbal/face" component where most pediatric coma scales are deficient. The IFS may prove to be a simple and practical bedside index of brain injury severity in children less than two years of age.

Cyanide interaction with redox modulatory sites enhances NMDA receptor responses

Activation of NMDA receptors plays an important role in cyanide neurotoxicity. Cyanide indirectly activates the receptor by inducing neuronal release of glutamate and also enhances receptor-mediated responses by a direct interaction with the receptor complex. This study investigated the mechanism in cerebellar granule cells by which cyanide enhances NMDA-induced Ca2+ influx. Cyanide (50 microM) increased the influx of Ca2+ over the NMDA concentration range of 0.5-500 microM. Experiments showed that cyanide does not interact with the receptor's glycine or PKC mediated phosphorylation regulatory sites. N-ethylmaleimide, a thiol alkylating agent which inactivates the redox regulatory sites of the receptor, blocked the enhancing effect of cyanide. Pretreatment of cells with 5,5-dithio-bis-2-nitrobenzoic acid (DTNB), a compound that oxidizes the receptor redox sites, had no effect on the response to cyanide. On the other hand, the nonpermeant reducing agents, dithiothreitol or cysteine, further increased the cyanide effect. These observations can be explained by cyanide interacting with redox sensitive disulfide groups that are not accessible to the non-permeant reducing agents. It is proposed that cyanide interacts with a redox site(s) located either on the intracellular receptor domain or in the transmembrane hydrophobic domain. Furthermore the enhancement by cyanide of the excitotoxic actions of NMDA involves receptor sites that are sensitive to oxidation/reduction and this interaction contributes to the neurotoxic action of cyanide.

Blood pressure, LDL cholesterol, and intima-media thickness: a test of the "response to injury" hypothesis of atherosclerosis

The "response to injury" hypothesis is a plausible model of the development of atherosclerosis supported by observations from animal models. The present study uses epidemiological data to investigate the hypothesis that wall damage due to hypertension is a precursor of low density lipoprotein cholesterol (LDL-C)-mediated atherosclerosis. The Los Angeles Atherosclerosis Study is following a cohort of 576 participants who were aged 40 to 60 years and were free of symptomatic cardiovascular disease at recruitment. Common carotid artery intima-media thickness (IMT) was assessed by B-mode ultrasonography. After exclusion for nonfasting blood draw and other missing data, 511 subjects were available for analysis. IMT was regressed on LDL-C within tertiles of systolic blood pressure (SBP): low (93 to 122 mm Hg), middle (123 to 132 mm Hg), and high (133 to 175 mm Hg). Covariates were age, sex, body height, body mass index, ethnicity, smoking status, diabetes, and pharmacological treatment for hypertension or hypercholesterolemia. IMT was significantly related to LDL-C in the high SBP group (beta=0.025+/-0.008, where beta values are IMT [mm]/LDL-C [mmol/L]; P=0.002) but not in the middle (beta=-0.006+/-0.008, P=0.39) or low (beta=-0.004+/-0.009, P=0.64) SBP group. The slope in the high SBP group was significantly greater than in the middle (P=0.004) or low (P=0.014) SBP group. Results were similar for women and men, and after the exclusion of diabetics and persons using antihypertensive or lipid-lowering medications. Elevated LDL-C was associated with increased IMT in the upper tertile of SBP but not in the lower tertiles. These findings are consistent with the hypothesis that wall injury due to elevated SBP increases the susceptibility of the artery wall to LDL-C-mediated atherogenesis.

Dynamic behaviors of the Ricker population model under a set of randomized perturbations

We studied the dynamics of the Ricker population model under perturbations by the discrete random variable epsilon which follows distribution P¿epsilon=a(i)¿=p(i),i=1,ellipsis,n,0<a(i)&z. Lt;1, n>/=1. Under the perturbations, n+1 blurred orbits appeared in the bifurcation diagram. Each of the n+1 blurred orbits consisted of n sub-orbits. The asymptotes of the n sub-orbits in one of the n+1 blurred orbits were N(t)=a(i) for i=1,ellipsis,n. For other n blurred orbits, the asymptotes of the n sub-orbits were N(t)=a(i)exp[r(1-a(i))]+a(j),j=1,2,ellipsis,n, for i=1,ellipsis,n, respectively. The effects of variances of the random variable epsilon on the bifurcation diagrams were examined. As the variance value increased, the bifurcation diagram became more blurred. Perturbation effects of the approximate continuous uniform random variable and random error were compared. The effects of the two perturbations on dynamics of the Ricker model were similar, but with differences. Under different perturbations, the attracting equilibrium points and two-cycle periods in the Ricker model were relatively stable. However, some dynamic properties, such as the periodic windows and the n-cycle periods (4), could not be observed even when the variance of a perturbation variable was very small. The process of reversal of the period-doubling, an important feature of the Ricker and other population models observed under constant perturbations, was relatively unstable under random perturbations.

The role of intrahepatic lymphocytes in mediating protective immunity induced by attenuated Plasmodium berghei sporozoites

Exposure to irradiated Plasmodium sporozoites (gamma-spz) results in protection against malaria. Like infectious spz, gamma-spz colonize hepatocytes to undergo maturation. Disruption of liver stage development prevents the generation of protection, which appears, therefore, to depend on liver stage antigens. Although some mechanisms of protection have been identified, they do not include a role for intrahepatic mononuclear cells (IHMC). We demonstrated that P. berghei gamma-spz-immune murine IHMC adoptively transfer protection to naive recipients. Characterization of intrahepatic CD4+ T cells revealed an immediate, albeit transient, response to gamma-spz, while the response of CD8+ T cells is delayed until acquisition of protection. It is presumed that activated CD8+ T cells home to the liver to die; gamma-spz-induced CD8+CD45RB(lo)CD44(hi) T cells, however, persist in the liver, but not the spleen, during protracted protection. The association between CD8+CD45RB(lo)CD44(hi) T cells and protection has been verified using MHC class I and CD1 knockout mice and mice with disrupted liver stage parasites. Based on kinetic studies, we propose that interferon-gamma, presumably released by intrahepatic effector CD8+ T cells, mediates protection; the persistence of CD8+ T cells is, in turn, linked to Plasmodium antigen depots and cytokines released by CD4+ T cells and/or NK T cells.