Four genes predict high risk of progression from smoldering to symptomatic multiple myeloma (SWOG S0120)

Multiple myeloma is preceded by an asymptomatic phase, comprising monoclonal gammopathy of uncertain significance and smoldering myeloma. Compared to the former, smoldering myeloma has a higher and non-uniform rate of progression to clinical myeloma, reflecting a subset of patients with higher risk. We evaluated the gene expression profile of smoldering myeloma plasma cells among 105 patients enrolled in a prospective observational trial at our institution, with a view to identifying a high-risk signature. Baseline clinical, bone marrow, cytogenetic and radiologic data were evaluated for their potential to predict time to therapy for symptomatic myeloma. A gene signature derived from four genes, at an optimal binary cut-point of 9.28, identified 14 patients (13%) with a 2-year therapy risk of 85.7%. Conversely, a low four-gene score (< 9.28) combined with baseline monoclonal protein < 3 g/dL and albumin ≥ 3.5 g/dL identified 61 patients with low-risk smoldering myeloma with a 5.0% chance of progression at 2 years. The top 40 probe sets showed concordance with indices of chromosome instability. These data demonstrate high discriminatory power of a gene-based assay and suggest a role for dysregulation of mitotic checkpoints in the context of genomic instability as a hallmark of high-risk smoldering myeloma.

Removing batch effects from purified plasma cell gene expression microarrays with modified ComBat

Background

Gene expression profiling (GEP) via microarray analysis is a widely used tool for assessing risk and other patient diagnostics in clinical settings. However, non-biological factors such as systematic changes in sample preparation, differences in scanners, and other potential batch effects are often unavoidable in long-term studies and meta-analysis. In order to reduce the impact of batch effects on microarray data, Johnson, Rabinovic, and Li developed ComBat for use when combining batches of gene expression microarray data.

We propose a modification to ComBat that centers data to the location and scale of a pre-determined, ‘gold-standard’ batch. This modified ComBat (M-Combat) is designed specifically in the context of meta-analysis and batch effect adjustment for use with predictive models that are validated and fixed on historical data from a ‘gold-standard’ batch.

Results

We combined data from MIRT across two batches (‘Old’ and ‘New’ Kit sample preparation) as well as external data sets from the HOVON-65/GMMG-HD4 and MRC-IX trials into a combined set, first without transformation and then with both ComBat and M-ComBat transformations. Fixed and validated gene risk signatures developed at MIRT on the Old Kit standard (GEP5, GEP70, and GEP80 risk scores) were compared across these combined data sets.

Both ComBat and M-ComBat eliminated all of the differences among probes caused by systematic batch effects (over 98% of all untransformed probes were significantly different by ANOVA with 0.01 q-value threshold reduced to zero significant probes with ComBat and M-ComBat). The agreement in mean and distribution of risk scores, as well as the proportion of high-risk subjects identified, coincided with the ‘gold-standard’ batch more with M-ComBat than with ComBat. The performance of risk scores improved overall using either ComBat or M-Combat; however, using M-ComBat and the original, optimal risk cutoffs allowed for greater ability in our study to identify smaller cohorts of high-risk subjects.

Conclusion

M-ComBat is a practical modification to an accepted method that offers greater power to control the location and scale of batch-effect adjusted data. M-ComBat allows for historical models to function as intended on future samples despite known, often unavoidable systematic changes to gene expression data.

Sentinel lymph node status in vulval cancer: systematic reviews of test accuracy and decision-analytic model-based economic evaluation

BACKGROUND

Vulval cancer causes 3-5% of all gynaecological malignancies and requires surgical removal and inguinofemoral lymphadenectomy (IFL). Complications affect > 50% of patients, including groin wound infection, lymphoedema and cellulitis. A sentinel lymph node (SLN) is the first groin node with the highest probability of malignancy. SLN biopsy would be useful if it could accurately identify patients in whom cancer has spread to the groin, without removing all groin nodes. SLNs can be identified by isosulfan blue dye and/or technetium-99 ((99m)Tc) radioactive tracer during lymphoscintigraphy. The blue dye/(99m)Tc procedure only detects SLN, not metastases - this requires histological examination, which can include ultrastaging and staining with conventional haematoxylin and eosin (H&E) or immunohistochemistry.

OBJECTIVES

To determine the test accuracy and cost-effectiveness of the SLN biopsy with (99m)Tc and/or blue dye compared with IFL or clinical follow-up for test negatives in vulval cancer, through systematic reviews and economic evaluation.

DATA SOURCES

Standard medical databases, including MEDLINE, EMBASE, Science Citation Index and The Cochrane Library, medical search gateways, reference lists of review articles and included studies were searched to January 2011.

METHODS

For accuracy and effectiveness, standard methods were used and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were to January 2011, with no language restrictions. Meta-analyses were carried out with Meta-Disc version 1.4 (Javier Zamora, Madrid, Spain) for accuracy; none was appropriate for effectiveness. The economic evaluation from a NHS perspective used a decision-tree model in DATA TreeAge Pro Healthcare 2001 (TreeAge Software, Inc., Williamstown, MA, USA). Six options (blue dye with H&E, blue dye with ultrastaging, (99m)Tc with H&E, (99m)Tc with ultrastaging, blue dye/(99m)Tc with H&E, blue dye/(99m)Tc with ultrastaging) were compared with IFL. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

For accuracy, of the 26 included studies, most evaluated (99m)Tc/blue dye combined. Four studies had clinical follow-up only for test negatives and five had clinical follow-up for all and IFL for test negatives. Numbers with no SLN found were difficult to distinguish from those with negative SLN biopsies. The largest group of 11 studies using (99m)Tc/blue dye, ultrastaging and immunohistochemistry had a pooled sensitivity of 95.6% [95% confidence interval (CI) 91.5% to 98.1%] and a specificity of 100% (95% CI 99.0% to 100%). Mean SLN detection rates were 94.6% for (99m)Tc, 68.7% for blue dye and 97.7% for both. One study measured global health status quality of life (QoL) and found no difference between SLN biopsy and IFL. One patient preference evaluation showed that 66% preferred IFL rather than a 5% false-negative rate from SLN biopsy. For effectiveness, of 14,038 references, one randomised controlled trial, three case-control studies and 13 case series were found. Approximately 50% died from vulval cancer and 50% from other causes during follow-ups. Recurrences were in the ratio of approximately 4 : 2 : 1 vulval, groin and distant, with more recurrences in node-positive patients. No studies reported QoL. For cost per death averted, IFL was less costly and more effective than strategies using SLN biopsy. For morbidity-free survival and long-term morbidity-free survival, (99m)Tc with ultrastaging was most cost-effective. Strategies with blue dye only and H&E only were never cost-effective. The incremental cost-effectiveness ratio for (99m)Tc with ultrastaging compared with IFL was £4300 per case of morbidity-free survival and £7100 per long-term morbidity-free survival.

LIMITATIONS

The main limitations of this study include the lack of good-quality evidence on accuracy, effectiveness and QoL. A large project such as this takes time to publish, so the most recent studies are not included.

CONCLUSIONS

A sensitive and specific combined metastatic SLN detection test and information on generic QoL in vulval cancer is urgently required.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Effect of citral and carvacrol on the susceptibility of Listeria monocytogenes and Listeria innocua to antibiotics

The aim of this study was to evaluate the antibiotic susceptibility of Listeria innocua (L. innocua) and Listeria monocytogenes (L. monocytogenes) cells in the presence of citral and carvacrol at sublethal concentrations in an agar medium. The presence of terpenes in the L. monocytogenes and L. innocua culture medium provided a reduction in the minimal inhibitory concentration (MIC) of all the antibiotics tested. These effects were dependent on the concentration of terpenes present in the culture medium. The combination of citral and carvacrol potentiated antibiotic activity by reducing the MIC values of bacitracin and colistin from 32.0 and 128.0 μg ml⁻¹ to 1.0 and 2.0 μg ml⁻¹, respectively. Thus, both Listeria species became more susceptible to these drugs. In this way, the colistin and bacitracin resistance of L. monocytogenes and L. innocua was reversed in the presence of terpenes. Results obtained in this study show that the phytochemicals citral and carvacrol potentiate antibiotic activity, reducing the MIC values of cultured L. monocytogenes and L. innocua.

SIGNIFICANCE AND IMPACT OF THE STUDY

Phytochemicals citral and carvacrol potentiate antibiotic activity of erythromycin, bacitracin and colistin by reducing the MIC values of cultured Listeria monocytogenes and Listeria innocua. This effect in reducing the MIC values of the antibiotics tested in both micro-organisms was increased when natural antimicrobials were combined. This finding indicated that the combination among terpenes and antibiotic may contribute in reducing the required dosage of antibiotics due to the possible effect of terpenes on permeation barrier of the micro-organism cell membrane.

Modulation of neurotrophin signaling by monoclonal antibodies

The neurotrophin family is comprised of the structurally related secreted proteins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophine-4 (NT-4). They bind and activate the tyrosine kinase receptors Trk A, B, and C in a ligand-specific manner and additionally bind a shared p75NTR receptor. The neurotrophins were originally defined by their ability to support the survival and maturation of embryonic neurons. However, they also control important physiological functions of the adult nervous system including learning and memory, sensation, and energy homeostasis. For example, NGF/trkA signaling is critical for normal and pathological sensation of pain. Likewise, the BDNF/trkB pathway controls feeding and metabolism, and its dysfunction leads to severe obesity. Antibodies can modulate neurotrophin signaling. Thus, NGF blocking agents can attenuate pain in several animal models, and a recombinant humanized NGF blocking antibody (Tanezumab) has shown promising results in human clinical trials for osteoarthritic pain. On the other hand trkB agonist antibodies can modulate food intake and body weight in rodents and nonhuman primates. The power of monoclonal antibodies to modulate neurotrophin signaling promises to turn the rich biological insights into novel human medicines.

Metronomic therapy is an effective salvage treatment for heavily pre-treated relapsed/refractory multiple myeloma

Relapsed/refractory multiple myeloma represents a major challenge in multiple myeloma therapy. For patients with relapsed/refractory multiple myeloma, we developed a treatment schema of metronomically scheduled drug therapy. We identified 186 patients who had been treated with metronomic therapy between March 2004 and January 2012 with a median follow up of 24.2 months. Median age was 61 years (range 36-83). Median number of prior therapies was 14 (range 1-51). Median number of completed metronomic therapy cycles was 1 (range 1-5), while 45 of 186 (25%) received 2 or more cycles. Responses included complete remission in 11 of 186 patients (6%), very good partial remission in 12 of 186 (7%), partial remission in 65 of 179 (36%), and minimal response in 29 of 186 (16%), for an overall response rate of 63% (117 of 186). Median overall survival and progression-free survival were 11.2 and 3.6 months, respectively. Hematologic toxicity grading was problematic as 146 of 186 (78%) of patients presented with at least grade 2 thrombocytopenia within 90 days prior to starting metronomic therapy. Grade 4 leukopenia, anemia, and/or thrombocytopenia following metronomic therapy occurred in 108 of 186 (58%), 12 of 186 (6%), and 147 of 186 (79%) patients, respectively. Incidence of grade 3-4 neutropenic fever was 4 of 186 (2%). Most patients (177 of 186, 95%) were treated in an outpatient unit and secondary admissions due to regimen-related toxicity occurred in 37 of 186 (20%). Treatment-related mortality was evident in 2 of 186 (1%). In conclusion, metronomic therapy is an effective late salvage treatment in relapsed/refractory multiple myeloma, with a high overall response rate and a favorable toxicity profile.

Cure candidates: Characteristics of >10yr progression-free survivors (PFS-10) and continuous CR (CCR-10) after total therapy 1 and 2 (TT1, TT2) for multiple myeloma (MM)

8603

Background: Our TT studies demonstrate that long term progression free survival is achievable in MM pointing to the possible curability of MM. We report here on the base line characteristics of 33/231 TT1 patients and 109/475 TT2 patients qualifying for PFS-10, including 45/245 randomized to the control arm and 64/230 randomized to thalidomide. Methods: Baseline and response levels were compared between <10yr and >=10yr survivors and logistic regression applied to identify the critical features linked to PFS-10 status. Results: Compared to the remainder, PFS>=10yr and CCR>=10yr were characterized by lower frequencies of cytogenetic abnormalities (CA), B2M>=3.5mg/L and age >=65yr. More females and more patients with platelets >150.000/uL qualified for the >=10yr category. Finally, timely administration of 2 transplants was also over-represented in these patients. Conclusions: Long-term survival PFS-10 and CCR-10 were adversely affected by by CA and elevated B2M levels. Females more frequently attained PFS-10. Assessment of MRD by 8-color flow cytometry in these patients is in progress and will be presented at the meeting. Clinical trial information: NCT00580372, NCT 00083551. [Table: see text] [Table: see text]

Prediction of acid lactic-bacteria growth in turkey ham processed by high hydrostatic pressure

High hydrostatic pressure (HHP) has been investigated and industrially applied to extend shelf life of meat-based products. Traditional ham packaged under microaerophilic conditions may sometimes present high lactic acid bacteria population during refrigerated storage, which limits shelf life due to development of unpleasant odor and greenish and sticky appearance. This study aimed at evaluating the shelf life of turkey ham pressurized at 400 MPa for 15 min and stored at 4, 8 and 12 °C, in comparison to the non pressurized product. The lactic acid bacteria population up to 10(7) CFU/g of product was set as the criteria to determine the limiting shelf life According to such parameter the pressurized sample achieved a commercial viability within 75 days when stored at 4 °C while the control lasted only 45 days. Predictive microbiology using Gompertz and Baranyi and Roberts models fitted well both for the pressurized and control samples. The results indicated that the high hydrostatic pressure treatment greatly increased the turkey ham commercial viability in comparison to the usual length, by slowing down the growth of microorganisms in the product.

Experimental evaluation of the nitrite sensitivity coefficient in granular anammox biomass

Nitrite is widely reported to inhibit anammox activity and growth. One modeling approach for nitrite impairment of anammox growth is the use of a nitrite sensitivity coefficient which increases the endogenous decay coefficient of anammox bacteria proportionally to nitrite concentration. The objective of this study was to measure nitrite concentration profiles within active anammox granules incubated at fixed bulk nitrite concentrations and to compare these with nitrite concentration profiles predicted by a biofilm model that incorporates the nitrite sensitivity coefficient. We developed an apparatus for the repeated measurement of nitrite concentration profiles along the radius of granular anammox biomass over a period of 6 days at fixed bulk nitrite concentrations. Granular anammox biomass was obtained from a two-stage bench-scale partial nitritation/anammox reactor system. There was no apparent effect of nitrite concentration on nitrite utilization kinetics after 6 days at exposures up to 90 mg NO(2)(-)-N/L. These findings suggest that anammox bacteria tolerate extended exposures to elevated nitrite concentrations, and in its present form, the nitrite sensitivity coefficient is not applicable for anammox growth modeling.

Limb activation ameliorates body-related deficits in spatial neglect

Many neglect patients show deficits in the mental representation of their contralesional body side or body parts, termed personal neglect. These deficits include impairments in identifying body parts on schematic drawings of human bodies. Limb activation and alertness cues have been shown to modulate neglect transiently, and are effective treatments for several symptoms of the neglect syndrome. Here, we tested on eight patients with right-hemispheric stroke and left-sided spatial neglect whether these two techniques modulate deficits in the mental representation of hands, assessed with a hand-test in which the subjects had to decide whether a depicted schematic hand belongs to the left or right side of the human body. The results showed that neglect patients made marginally significant (p = 0.065) more errors in left-hand-decisions than right-hand-decisions, indicating a neglect-specific disorder. Moreover, we found that left-sided limb activation but not non-lateralized alertness cueing (a loud noise immediately before patients made their perceptual decision) significantly reduced misidentifications for depicted left hands as compared to baseline. No effect of any intervention was observed on error rates for depicted right hands. We conclude that the amelioration of the performance in the hand task is modulated by the activation of the body schema or other body representations through left-sided limb activation.

Renal insufficiency retains adverse prognostic implications despite renal function improvement following Total Therapy for newly diagnosed multiple myeloma

Renal insufficiency (RI) is a frequent complication of multiple myeloma (MM) with negative consequences for patient survival. The improved clinical outcome with successive Total Therapy (TT) protocols was limited to patients without RI. We therefore performed a retrospective analysis of overall survival, progression-free survival and time to progression (TTP) of patients enrolled in TT2 and TT3 in relationship to RI present at baseline and pre-transplant. Glomerular filtration rate was graded in four renal classes (RCs), RC1–RC4 (RC1 ⩾90 ml/min/1.73 m², RC2 60–89 ml/min/1.73 m², RC3 30–59 ml/min/1.73 m² and RC4 <30 ml/min/1.73 m²). RC1–3 had comparable clinical outcomes while RC4 was deleterious, even after improvement to better RC after transplant. Among the 85% of patients with gene expression profiling defined low-risk MM, Cox regression modeling of baseline and pre-transplant features, which also took into consideration RC improvement and MM complete response (CR), identified the presence of metaphase cytogenetic abnormalities and baseline RC4 as independent variables linked to inferior TTP post-transplant, while MM CR reduced the risk of progression and TTP by more than 60%. Failure to improve clinical outcomes despite RI improvement suggested MM-related causes. Although distinguishing RC4 from RC<4, 46 gene probes bore no apparent relationship to MM biology or survival.

Superior vena cava syndrome secondary to thyroid cancer

It is uncommon for thyroid cancer to present with superior vena cava syndrome. Obstruction of superior vena cava can develop as a result of intrinsic and extrinsic spread of the thyroid cancer. The usual presentation of this disease entity is a neck mass with symptoms and signs suggestive of superior vena cava obstruction. Superior vena cava obstruction is commonly caused by lung cancer and lymphoma. However, thyroid cancer can cause superior vena cava obstruction by downward tumour spread into the mediastinum causing extrinsic compression, which will lead to narrowing and thrombosis of the major venous system in the chest. Paraganglioma can also present with superior vena cava obstruction and it mimics thyroid cancer microscopically. Proper staining should be performed to differentiate between the two diseases. This could be the first case of this kind reported in the literature.

Prosurvival effect of human wild-type alpha-synuclein on MPTP-induced toxicity to central but not peripheral catecholaminergic neurons isolated from transgenic mice

In the present work we report the generation of a new line of alpha-synuclein (alpha-SYN) transgenic mice in which the human wild-type alpha-SYN cDNA is expressed under the control of a tyrosine hydroxylase (TH) promoter. We provide evidence that the ectopic protein is found in TH expressing neurons of both central and peripheral nervous systems. The transgene is expressed very early in development coinciding with the activity of the TH promoter and in the adult brain the human protein distributes normally to the nerve endings and cell bodies of dopaminergic nigral neurons without any evidence of abnormal aggregation. Our results indicate that expression of human wild-type alpha-SYN does not affect normal development or maintenance of TH immunoreactive nigral neurons, striatal dopamine content, or locomotor activity. Systemic administration of the parkinsonian neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induces a loss of TH immunoreactive nigral neurons and terminals and of dopamine levels to the same degree in both transgenic and non-transgenic adult mice. Intoxication also results in a similar loss of cardiac noradrenaline in both genotypes. Surprisingly, cultured transgenic ventral mesencephalic fetal dopaminergic neurons exhibit complete resistance to cell death induced by 1-methyl-4-phenylpyridinium ion (MPP(+)) intoxication, without changes in dopamine transporter (DAT) surface levels. Interestingly, this protection is not observed in other populations of catecholaminergic neurons such as peripheral sympathetic neurons, despite their high sensitivity to MPP(+)in vitro.

Elevated testosterone and hypergonadotropism in active adolescents of normal weight with oligomenorrhea

STUDY OBJECTIVE

Oligomenorrhea in active adolescent females of normal weight is presumed to be related to hypoestrogenism secondary to physical activity and decreased fat mass. We hypothesized that active adolescents with oligomenorrhea would have lower estrogen levels than normal controls with similar levels of cardiovascular fitness.

DESIGN/PARTICIPANTS

Twenty healthy participants between the ages of 16 and 20 years were recruited at least 2 years postmenarche. Adolescents reporting fewer than 9 cycles a year (n = 6) were compared to 14 controls with monthly menstrual cycles. Histories of eating disorder, hirsutism, severe acne, depression, or amenorrhea were cause for exclusion.

MAIN OUTCOME MEASURES

Body composition and bone density were measured by total body dual x-ray absorpitometry. Cardiovascular fitness was evaluated by measuring oxygen consumption during exercise. Control subjects were matched by age, body mass index (BMI), and fitness level. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, progesterone, and estradiol were obtained. Statistical analysis was performed using SAS 9.1.

RESULTS

Cardiovascular fitness in both groups was within normal limits for age. No significant differences in BMI, estradiol concentrations, or bone density were found, but trunk fat mass was lower in adolescents with oligomenorrhea who also reported more frequent exercise. Testosterone concentrations and LH/FSH ratios were significantly higher in participants with irregular menstrual cycles (P = 0.0018 and <0.001, respectively).

CONCLUSION

Adolescents with oligomenorrhea were leaner, yet they had higher testosterone levels and a greater LH/FSH ratio than their BMI-matched, cyclic counterparts. We hypothesize that, in active adolescents of normal weight, elevated androgen and LH concentrations are linked to ovarian dysfunction, which can masquerade as exercise-induced oligomenorrhea.

nDEP microwells for single-cell patterning in physiological media

We present a novel technique to accurately position single cells on a substrate using negative dielectrophoresis and cell-substrate adhesion. The cells are suspended in physiological media throughout the patterning process. We also verify the biocompatibility of this method by demonstrating that the patterned cells proliferate and show normal morphology. We calculate the temperatures and transmembrane potential that cells in the device experience and compare them to physiologically acceptable levels described in previous studies.

Impact of fatness, fitness, and ethnicity on the relationship of nocturnal ghrelin to 24-hour luteinizing hormone concentrations in adolescent girls

CONTEXT

Ghrelin is related to energy balance that regulates food intake.

OBJECTIVE

The aim was to explore whether ghrelin would be linked to differences in fitness in adolescent girls, whose menstrual cycles are sensitive to changes in energy balance.

METHODS

A total of 72 girls, ages 14-21 yr, including five with amenorrhea, were studied in the follicular phase. LH was sampled every 10 min over 24-h, and ghrelin was measured hourly between 2300 and 0300 h. Body composition was measured by dual x-ray absorptiometry. Fitness was characterized by reported frequency of exercise per week and by maximal oxygen consumption with "high" vs. "low" fitness groups defined from maximal oxygen consumption norms for this population. Data were analyzed with SAS software (SAS Institute Inc., Cary, NC).

RESULTS

Ghrelin was related to percent body fat (P = 0.038; R(2) 0.07), weekly exercise (P = 0.032; R(2) 0.07), and 24-h mean LH (P = 0.002; R(2) 0.13). The ghrelin relationship with LH was more pronounced in the low-fitness group. In multiple regression models, 24-h LH was an independent predictor of ghrelin after adjusting for percent body fat, fitness, exercise, or age. Ghrelin was higher in Caucasian girls than in African-American girls after adjusting for covariates at 0200 h (P = 0.017).

CONCLUSIONS

Twenty-four-hour LH is an independent predictor of nighttime ghrelin concentrations in postpubertal adolescent girls. Diverging patterns in ghrelin may reflect differences in exercise patterns and/or may be influenced by ethnicity. These data introduce ghrelin as a biomarker of individual differences in energy balance during the menstrual cycle and across ethnicities.

Differential expression of genes encoding tight junction proteins in colorectal cancer: frequent dysregulation of claudin-1, -8 and -12

BACKGROUND AND AIMS

As integral membrane proteins, claudins form tight junctions together with occludin. Several claudins were shown to be up-regulated in various cancer types. We performed an expression analysis of genes encoding tight junction proteins to display differential gene expression on RNA and protein level and to identify and validate potential targets for colorectal cancer (CRC) therapy.

PATIENTS AND METHODS

Amplified and biotinylated cRNA from 30 microdissected CRC specimen and corresponding normal tissues was hybridized to Affymetrix U133set GeneChips. Quantification of differential protein expression of claudin-1, -8 and -12 between normal and corresponding tumour tissues was performed by Western blot analyses. Paraffin-embedded CRC tissue samples, colon cancer cell lines and normal tissue microarray were analysed for protein expression of claudin-1 by immunohistochemistry (IHC).

RESULTS

Claudin-1 (CLDN1) and -12 (CLDN12) are frequently overexpressed in CRC, whereas claudin-8 (CLDN8) shows down-regulation in tumour tissue on RNA level. Quantification of proteins confirmed the overexpression of claudin-1 in tumour tissues, whereas changes of claudin-8 and -12 were not significantly detectable on protein level. IHC confirmed the markedly elevated expression level of claudin-1 in the majority of CRC, showing membranous and intracellular vesicular staining.

CONCLUSIONS

Differential expression of genes encoding claudins in CRC suggests that these tight junction proteins may be associated to and involved in tumorigenesis. CLDN1 is frequently up-regulated in large proportion of CRC and may represent potential target molecule for blocking studies in CRC.

Cell patterning chip for controlling the stem cell microenvironment

Cell-cell signaling is an important component of the stem cell microenvironment, affecting both differentiation and self-renewal. However, traditional cell-culture techniques do not provide precise control over cell-cell interactions, while existing cell-patterning technologies are limited when used with proliferating or motile cells. To address these limitations, we created the Bio Flip Chip (BFC), a microfabricated polymer chip containing thousands of microwells, each sized to trap down to a single stem cell. We have demonstrated the functionality of the BFC by patterning a 50 x 50 grid of murine embryonic stem cells (mESCs), with patterning efficiencies >75%, onto a variety of substrates--a cell-culture dish patterned with gelatin, a 3-D substrate, and even another layer of cells. We also used the BFC to pattern small groups of cells, with and without cell-cell contact, allowing incremental and independent control of contact-mediated signaling. We present quantitative evidence that cell-cell contact plays an important role in depressing mESC colony formation, and show that E-cadherin is involved in this negative regulatory pathway. Thus, by allowing exquisite control of the cellular microenvironment, we provide a technology that enables new applications in tissue engineering and regenerative medicine.

Twenty-four hour growth hormone and leptin secretion in active postpubertal adolescent girls: impact of fitness, fatness, and age at menarche

CONTEXT

GH is strongly related to body composition, physical activity, and pubertal progression. Adolescent girls decrease physical activity during puberty, whereas their weight increases. Because leptin is a good index of energy balance in active young women, we hypothesized that leptin is related to GH secretion in this population while taking into account fitness, fatness, and age at menarche.

METHODS

We measured body composition and maximal oxygen consumption (VO(2)max) in 37 postpubertal adolescent girls aged 16-21 yr. GH was sampled every 10 min and leptin hourly for 24 h. We first analyzed 6-h time blocks by repeated measures for GH and leptin, with body mass index (BMI), percent body fat, and VO(2)max as covariates for the entire group and a lean subgroup. The deconvolution method was used to characterize GH pulsatility from individual time points.

RESULTS

GH varied through the day (P < 0.0001), with the highest concentrations overnight. BMI, percent body fat, and VO(2)max were related to GH concentrations in the entire group, whereas leptin predicted GH in the entire group as well as the lean subgroup of girls. Higher leptin was related to lower GH concentrations (P = 0.011), regardless of time. A log leptin level increase by 1 unit decreased GH by 27%. Pulsatility characteristics showed a 1-yr increase of age at menarche increasing total GH input by 20% (P = 0.0035) independently from BMI.

CONCLUSION

In postpubertal adolescent girls, leptin is related to GH concentration across the lean to overweight BMI spectrum. GH pulsatile secretion was greater in girls with later age at menarche.

[Surgical treatment of obesity and its side effects is effective]

Obesity is a chronic condition associated with a reduction in the quality of life and a high risk for disease and death and requiring long-term care. In Germany, 51.4% of the population is overweight, with 9 million suffering from obesity and its consequences, such as hypertension, diabetes and sleep apnea. In addition, the number of patients undergoing treatment for painful chronic-degenerative disease of the joints is on the increase. After first exhausting all conservative therapeutic options, effective surgical measures can bring about a lasting overweight reduction of up to 50%. By this means, both pain and adverse consequences of obesity can be improved.

Familial ovarian cancer screening

Familial predisposition accounts for approximately 10% of epithelial ovarian cancer. Identification and management of at-risk families is therefore an important area that bridges gynaecological and clinical genetic practice. The efficacy of screening for ovarian cancer in both high- and low-risk populations is currently of unproven benefit and is associated with some risks related to false-positive results. In contrast to the general population, preventive surgery is a realistic proposition for many women at high-risk. Although prophylactic bilateral salpingo-oophorectomy prevents ovarian and tubal cancer and reduces the risk of breast cancer, this option is unsuitable for women who have yet to complete their families or who are unwilling to undergo surgery. There is therefore a continued demand for screening in the high-risk population. This chapter discusses the limitations of screening, the circumstances under which screening is appropriate and current screening guidelines. Ongoing and future research that should help to provide additional information about this area is also reviewed.

Quantitative modeling of dielectrophoretic traps

We present quantitative modeling software for simulating multiple forces acting on a single particle in a microsystem. In this paper, we focus on dielectrophoretic (DEP) trapping of single cells against fluid flow. The software effectively models the trapping behavior for a range of particles including beads, mammalian cells, viruses, and bacteria. In addition, the software can be used to reveal useful information about the DEP traps - such as multipolar DEP force effects, trap size-selectivity, and effects from varying the flow chamber height. Our modeling software thus serves as a predictive tool, enabling the design of novel DEP traps with superior performance over existing trap geometries. In addition, the software can evaluate a range of trap dimensions to determine the effects on trapping behavior, thus optimizing the trap geometry before it is even fabricated. The software is freely available to the scientific community at: .

Highlights of the 3rd International Conference on High Pressure Bioscience and Biotechnology

The 3rd International Conference on High Pressure Bioscience and Biotechnology was held in the city of Rio de Janeiro from September 27 to September 30, 2004. The meeting, promoted by the International Association of High Pressure Bioscience and Biotechnology (IAHPBB), congregated top scientists and researchers from all over the world. In common, they shared the use of hydrostatic pressure for research, technical development, or industrial applications. The meeting consisted of invited lectures, contributed papers and a well-attended poster session. Very exciting discussions were held inside and outside the sessions, and the goals of discussing state-of-the-art data and establishing working collaborations and co-operations were fully attained.

Differential regulation of beta-defensin expression in human skin by microbial stimuli

In response to infection, epithelia mount an innate immune response that includes the production of antimicrobial peptides. However, the pathways that connect infection and inflammation with the induction of antimicrobial peptides in epithelia are not understood. We analyzed the molecular links between infection and the expression of three antimicrobial peptides of the beta-defensin family, human beta-defensin (hBD)-1, hBD-2, and hBD-3 in the human epidermis. After exposure to microbe-derived molecules, both monocytes and lymphocytes stimulated the epidermal expression of hBD-1, hBD-2, and hBD-3. The induced expression of hBD-3 was mediated by transactivation of the epidermal growth factor receptor. The mechanisms of induction of hBD-1 and hBD-3 were distinct from each other and from the IL-1-dependent induction of hBD-2 expression. Thus during inflammation, epidermal expression of beta-defensins is mediated by at least three different mechanisms.

The genome of the social amoeba Dictyostelium discoideum

The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes of this organism encode approximately 12,500 predicted proteins, a high proportion of which have long, repetitive amino acid tracts. There are many genes for polyketide synthases and ABC transporters, suggesting an extensive secondary metabolism for producing and exporting small molecules. The genome is rich in complex repeats, one class of which is clustered and may serve as centromeres. Partial copies of the extrachromosomal ribosomal DNA (rDNA) element are found at the ends of each chromosome, suggesting a novel telomere structure and the use of a common mechanism to maintain both the rDNA and chromosomal termini. A proteome-based phylogeny shows that the amoebozoa diverged from the animal-fungal lineage after the plant-animal split, but Dictyostelium seems to have retained more of the diversity of the ancestral genome than have plants, animals or fungi.