Design, construction and evaluation of a miniature soil bin plus predicting the measured parameters during primary tests using ANFIS

A clear understanding of soil-machine interaction is utilised in many areas, such as rational design and performance optimisation of soil-engaging tools/implements. This research developed a new soil bin to investigate the interaction between soil-narrow tines and soil failure. The new soil bin consisted of a chassis, a bin, a variable speed carriage and a bolt and nut type power transmission system between the motor and carriage. The design criteria of the new soil bin were based on the drive system's immediate acceleration of the carriage unit. A curved chisel tine was tested to evaluate the system's capabilities. Three parameters, including lift height, failure side area and forward failure distance, were investigated at two forward speeds of 0.037 and 0.05 m/s and three rake angles of 5°, 10° and 20°. An analysis of variance (ANOVA) test revealed the effect of rake angle on the lift height, failure side area, and forward failure distance was significant (P < 0.01). However, the forward speed did not have any significant influence on parameters. Also, the lift height and failure side area increased significantly (P < 0.01) by increasing the rake angle, while the forward failure distance decreased. Regarding soil failure, the results were in harmony with Godwin and Spoor's model. The regression and ANFIS models were developed to predict the output parameters by considering input parameters. The R2 values and ANFIS models were 0.4895, 0.7264, 0.9856, and 0.9999, 1, 1, respectively, for lift height, side area, and forward distance. Therefore, ANFIS approach was more accurate for predicting soil failure parameters.

Electrospun Propolis-coated PLGA Scaffold Enhances the Osteoinduction of Mesenchymal Stem Cells

BACKGROUND

Major injuries that are caused by trauma and cancer can not be repaired through bone remodeling. The goal of bone regeneration by tissue engineering approaches is to fabricate bone implants in order to restore bone structure and functions. The use of stem cells and polymer scaffolds provides the conditions for tissue regeneration based on tissue engineering.

OBJECTIVE

This study aimed to fabricate a combined matrix of poly(lactide-co-glycolide) (PLGA) and propolis extract, which is a mixture of pollen and beeswax collected by bees from certain plants and has long been used in traditional herbal medicine, to promote the osteogenic differentiation of human adipose- derived mesenchymal stem cells (AD-MSCs).

METHODS

The scaffold was fabricated through electrospinning and was immersed in a propolis extract solution. Then, AD-MSCs were cultured and differentiated into the osteogenic lineage. The cell viability on the scaffold was evaluated by MTT assay. Osteogenic differentiation of the seeded stem cells was detected by evaluating calcium content, alkaline phosphatase (ALP) activity, and the expression of bonespecific genes.

RESULTS

The viability of cells was not affected by propolis-coated and uncoated fabricated scaffolds, while higher calcium content, ALP activity, and expression of RUNX-2, type I collagen, osteocalcin, and osteonectin were observed in cells differentiated on propolis-coated PLGA scaffold on days 7, 14, and 21 of differentiation compared to PLGA scaffold.

CONCLUSION

The results of this study showed that the presence of propolis in the scaffold could lead to better cell attachment and strengthen the osteoinduction process in stem cells.

Control and study of bio-inspired quadrupedal gaits on an underactuated miniature robot

This paper presents a linear quadratic Gaussian (LQG) controller for controlling the gait of a miniature, foldable quadruped robot with individually actuated and controlled legs (MinIAQ-III). The controller is implemented on a palm-size robot made by folding an acetate sheet. MinIAQ-III has four DC motors for actuation and four rotary sensors for feedback. It is one of the few untethered robots on a miniature scale capable of working with different gaits with the help of its individually-actuated legs and the developed controller. The presented LQG controller controls each leg's positions and rotational speeds by measuring the positions and estimating the rotational speeds, respectively. With the precise gait control on the robot, we demonstrate different gaits inspired by quadrupeds in nature and compare the simulation and experiment results for some of the gaits. An extensive simulation environment developed for robot dynamics helps us to predict the locomotion behavior of the robot in various environments. The match between the simulation and the experiment results shows that the proposed LQG controller can successfully control the miniature robot's gaits. We also conduct a case study that shows the potential to use the simulation to achieve different robot behavior. In a case study, we present our robot performing a prancing similar to horses. We use the simulation environment to find the required motor configuration phases and physical parameters, which can make our robot prance. After finding the parameters in simulation, we replicate the configuration in our robot and observe the robot making the same moves as the simulation.

Non -fatal overdose among people who inject drugs in Tehran, Iran

BACKGROUND

With increasing frequencies of non-fatal overdose in people who inject drugs (PWID), it is essential to improve our knowledge about associated risk factors for overdose to inform overdose prevention and assistance programs. The aim of present study was to determine the prevalence of non-fatal overdose and the associated risk factors among PWID in Tehran, Iran.

METHODS

Snowball sampling was used to collect data from 465 participants in Tehran using a cross-sectional survey. Consenting participants who reported drug injecting in the past month and were able to speak and comprehend Farsi enough to respond to survey questions were interviewed. The endpoint of interest was non-fatal overdose in the previous 6 months, or answering "Yes" to the question: "In the last six months, have you ever overdosed by accident? (at least once)". We used STATA v. 14 for this analysis. Statistical significance was defined as p < 0.05 for all analyses.

RESULTS

Of 465 PWIDs who participated in this study, all were male, and about half had less than a high school education. The prevalence of self-reported non-fatal overdose in the past 6 months was 38% (CI95%: 34, 43%). Our findings indicate that characteristics and behaviors that were associated with an increased risk of experiencing an overdose in the past 6 months were drug use initiation under 22 years (AOR =2.2, P < 0.05), using methamphetamine (AOR =2.8, P < 0.05), and using multiple drugs at the same time (AOR =2.1, P < 0.05). Also, more recent initiates to injecting (< 2 years) had an increased risk of experiencing an overdose in the past 6 months. The odds of experiencing a non-fatal overdose among PWIDs who regularly attended NSP were 0.6 times less than for those who did not attend regularly (OR = 0.6,95% CI: 0.2-0.9).

CONCLUSION

Methamphetamine and alcohol use were the most significant association for non-fatal overdose among PWIDs. Our results indicate that intervention and prevention initiatives seeking to reduce overdoses among PWIDs should not only be focused on the primary drug used but also the use of alcohol and poly-drug use.

Perceived effectiveness of clinical pathway software: A before-after study in the Netherlands

BACKGROUND

Clinical pathways (CPs) increase in popularity and are known to lead to several benefits in the hospital environment. Clinical pathways can be either paper-based or software-based. It is known that paper-based CPs can result in more paperwork instead of simplifying daily routines of healthcare workers. Insufficient research has been done on the acceptance of software-based CPs by different user groups. Our aim in this study was to assess the effectiveness of the software-based CPs (CPS) from the perspective of healthcare professionals in the hospital environment as well as to investigate the differences in perceived effectiveness between user groups.

METHODS

Using surveys and interviews, data were collected in four departments of an academic medical center. A distinction was made between decision makers (DM) and executive staff (ES). The surveys contained questions based on the Technology Acceptance Model and four objectives of the software defined by the hospital. Statistical tests were used to investigate the effectiveness of CPS and study the differences between DM and ES. Interviews were recorded and transcribed based on grounded theory principals.

RESULTS

After implementation, monitoring protocol-based working was significantly improved (p = .026) and significantly higher efficiency on the work floor was reported (p = .046). ES perceived the software as less useful than expected (Md = 3.25 vs. Md = 2.75, p = .028) compared to DM and were less convinced of its ability to improve monitoring protocol-based working. The most important benefits of CPS as perceived by its users are the better overview of tasks it provides and facilitating documentation. Negative aspects mentioned were the lack of usability and the inflexibility of the software, and particularly ES claimed that the software did not increase their effectiveness.

CONCLUSION

Our study showed that CPS is effective from healthcare professionals' perspective due to its ability to increase monitoring of protocol-based working and by enhancing the efficiency on the work floor. However, the users also acknowledge that the software lacks usability and is not flexible enough, which results in an additional workload. Policy makers should be more focused on informing and training executive staff more thoroughly when implementing a CPS. Our results strongly suggest that executive staff members need to be convinced of its usefulness and the added value a CPS provides. Preferably, they should be involved in the design phase of the software.

Sustained release of TGF-β1 via genetically-modified cells induces the chondrogenic differentiation of mesenchymal stem cells encapsulated in alginate sulfate hydrogels

Strategies based on growth factor (GF) delivery have attracted considerable attention in tissue engineering applications. Among different GFs, transforming growth factor beta 1 (TGF-β1) is considered to be a potent factor for inducing chondrogenesis. In the present study, an expression cassette encoding the TGF-β1 protein was prepared and transfected into the SP2/0-Ag14 cell line. The confocal microscopy of the transfected cells was performed to confirm the correct transfection process. The expression and in vitro release kinetics of the recombinant TGF-β1 were assessed by western blot analysis and ELISA, respectively. Moreover, the biological activity of the expressed protein was compared with that of a commercially available product. The chondrogenic effects of the sustained release of the recombinant TGF-β1 in an in vitro co-culture system were evaluated using a migration assay and real-time PCR. Results of confocal microscopy confirmed the successful transfection of the vector-encoding TGF-β1 protein into the SP2/0-Ag14 cells. The bioactivity of the produced protein was in the range of the commercial product. The sustained release of the TGF-β1 protein via SP2/0-Ag14 cells encapsulated in hydrogels encouraged the migration of adipose-derived MSCs. In addition, the expression analysis of chondrogenesis-related genes revealed that the pretreatment of encapsulated Ad-MSCs cells in alginate sulfate hydrogels through their exposure to the sustained release of TGF-β1 is an efficient approach before transplantation of cells into the body.

Pros and Cons of Clinical Pathway Software Management: A Qualitative Study

In this study we aimed to assess the perceived effectiveness of clinical pathway management software for healthcare professionals. A case study on the clinical pathway management software program Check-It was performed in three departments at an academic medical center. Four months after the implementation of the software, interviews were held with healthcare professionals who work with the system. The interview questions were posed in a semi-structured interview format and the participant were asked about the perceived positive or negative effects of Check-It, and whether they thought the software is effective for them. The interviews were recorded and transcribed based on grounded theory, using different coding techniques. Our results showed fewer overlooked tasks, pre-filled orders and letters, better overview, and increased protocol insight as positive aspects of using the software. Being not flexible enough was experienced as a negative aspect.

Aberrant promoter hypermethylation of selected apoptotic genes in childhood acute lymphoblastic leukemia among North Indian population

Promoter hypermethylation mediates gene silencing in many neoplasms. Acute leukemia has been reported to harbor multiple genes aberrantly silenced by hypermethylation.

AIM

In present study, we investigated the prevalence of hypermethylation of caspase-8 (CASP8), TMS1 and DAPK genes in correlation with clinicopathological factors in childhood acute lymphoblastic leukemia (ALL).

MATERIALS AND METHODS

A case-control study has been conducted based on bone marrow and peripheral blood samples from 125 ALL patients and 100 sex-age matched healthy controls. Methylation specific polymerase chain reaction (PCR) and bisulfite sequencing PCR was performed to analyze the methylation status of these genes. Reverse transcription PCR and real time PCR was carried out to determine changes in the mRNA expression level of the genes due to hypermethylation.

RESULTS

Hypermethylation of the 5´CpG islands of the CASP8, TMS1 and DAPK gene promoters was found in 3.2, 6.4, and 13.6% of 125 childhood ALL samples from north Indian population, respectively. There were significant differences in pattern of hypermethylation of TMS1 (p = 0.045) and DAPK (p &lt; 0.001) between patients and healthy controls. Down-regulation of mRNA expression was found in cases in which CASP8, TMS1 and DAPK were hypermethylated.

CONCLUSIONS

The present study indicated the impact of hypermethylation-mediated inactivation of CASP8, TMS1 and DAPK genes, which is associated with risk of childhood ALL. This abnormality occurs in leukemogenesis and it may be used as a biomarker and for predicting the prognosis of ALL.

Acceleration of bone regeneration in bioactive glass/gelatin composite scaffolds seeded with bone marrow-derived mesenchymal stem cells over-expressing bone morphogenetic protein-7

In this research, the osteoinduction effect of a novel variant of bone morphogenetic protein-7 (BMP-7), delivered through bone marrow mesenchymal stem cells (BM-MSCs) seeded on bioactive glass/gelatin nanocomposite scaffolds, was evaluated in a calvarial critical size defect in rats. After being harvested and characterized in vitro, BM-MSCs were infected by a plasmid vector containing BMP-7 encoding gene enriched with a heparin-binding site (B2BMP-7) to assess its osteogenic effects in vivo. The animals were randomly categorized into three groups receiving the scaffold alone (group I), the scaffold seeded with BM-MSCs (group II), and the scaffold seeded with manipulated BM-MSCs (group III). After 2, 4 and 12 postoperative weeks, the animals were sacrificed and the harvested specimens were analyzed using histological and immunohistochemical staining. The results of in vitro tests (preliminary screening) showed that the synthesized scaffolds were biocompatible constructs supporting cell attachment and expansion. The in vivo results revealed higher osteogenesis in the defects filled with the B2BMP-7 excreting BM-MSCs/scaffolds compared to the other two groups. After 12weeks of implantation, fully mature newly formed bone was detected throughout the damaged site, which indicates a synergistic effect of cells, scaffolds and growth factors in the process of tissue regeneration. Therefore, bioactive glass-containing scaffolds pre-seeded with manipulated BM-MSCs exhibit an effective combination to improve osteogenesis in bone defects, and the approach followed in this work could have a significant impact in the development of novel tissue engineering constructs.

Assessment of the quality of fall detection and management in primary care in the Netherlands based on the ACOVE quality indicators

We determined adherence to nine fall-related ACOVE quality indicators to investigate the quality of management of falls in the elderly population by general practitioners in the Netherlands. Our findings demonstrate overall low adherence to these indicators, possibly indicating insufficiency in the quality of fall management. Most indicators showed a positive association between increased risk for functional decline and adherence, four of which with statistical significance.

INTRODUCTION

This study aims to investigate the quality of detection and management of falls in the elderly population by general practitioners in the Netherlands, using the Assessing Care of Vulnerable Elders (ACOVE) quality indicators.

METHODS

Community-dwelling persons aged 70 years or above, registered in participating general practices, were asked to fill in a questionnaire designed to determine general practitioner (GP) adherence to fall-related indicators. We used logistic regression to estimate the association between increased risk for functional decline-quantified by the Identification of Seniors At Risk for Primary Care score-and adherence. We then cross-validated the self-reported falls with medical records.

RESULTS

Of the 950 elders responding to our questionnaire, only 10.6 % reported that their GP proactively asked them about falls. Of the 160 patients who reported two or more falls, or one fall for which they visited the GP, only 23.1 % had fall documentation in their records. Adherence ranged between 13.6 and 48.6 %. There was a significant positive association between the ISAR-PC scores and adherence in four QIs. Documentation of falls was highest (36.7 %) in patients whom the GP had proactively asked about falls.

CONCLUSION

Based on patient self-reports, adherence to the ACOVE fall-related indicators was poor, suggesting that the quality of evaluation and management of falls in community-dwelling older persons in the Netherlands is poor. The documentation of falls and fall-related risk factors was also poor. However, for most QIs, adherence to them increased with the increase in the risk of functional decline.

Association of Htra1 gene polymorphisms with the risk of developing AMD in Iranian population

BACKGROUND

Half of the cases of vision loss in people under 60 years of age have been attributed to age-related macular degeneration (AMD). This is a multifactorial disease with late onset. It has been demonstrated that many different genetic loci are implicated in the risk of developing AMD in different populations. In the current study, we investigated the association of high-temperature ‎requirement A-1 (HTRA1) gene polymorphisms with the risk of developing AMD in the Iranian population.

METHODS

Genomic DNA samples were extracted from 120 patients with AMD and 120 healthy age- and sex-matched controls. A 385 base-pair fragment of the HTRA1 gene promoter region was amplified using the polymerase chain reaction (PCR) technique and sequenced. The frequencies of the alleles were calculated and statistical analysis was performed using SPSS software.

RESULTS

Our study demonstrated that the rate of polymorphisms rs11200638 -625 G>A and rs2672598 -487T>C were significantly greater in AMD patients than in healthy controls from the Iranian population.

CONCLUSIONS

The results of our study indicate that HTRA1 gene promoter region polymorphisms are associated with the risk of developing AMD in the Iranian population.

Tissue fatty acid composition and secretory phospholipase-A2 activity in oral squamous cell carcinoma

PURPOSE

Oral squamous cell carcinoma (OSCC) is a remarkable health problem worldwide, but its pathogenesis remains unknown. The aim of this study was to compare fat composition and secretory phospholipase-A2 (sPLA2) activity between the malignant and adjacent normal squamous tissues in patients with OSCC.

METHODS

Paired samples of malignant squamous and adjacent normal-appearing tissues were collected from 27 patients with OSCC. The fatty acid composition in the obtained tissues was determined by gas liquid chromatography. Tissue enzyme activities of sPLA2 were measured using the standard assay with Diheptanoyl Thio-Phosphatidylcholine as substrate.

RESULTS

In the OSCC tissue, the level of stearic acid (18:0) and activity of sPLA2 were higher (P < 0.001), and the levels of oleic acid (18:1n-9) and linoleic acid (18:2n-6) were lower than that in the adjacent normal-appearing squamous tissue (P < 0.001). The activity of sPLA2 in OSCC was strongly negatively correlated with the amount of 18:2n-6 (r = -0.41, P < 0.001). Negative significant associations were observed between the OSCC invasion and tissue levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHE).

CONCLUSION

The changes in the fatty acid composition and sPLA2 activity may be regarded as indicators of altered lipid metabolism occurring in vivo during squamous cell carcinogenesis.

The -137G/C polymorphism of interleukin 18 promoter and risk of HIV-1 infection and its progression to AIDS

A growing body of evidence suggests that host genetic factors play an important role both in susceptibility to human immunodeficiency virus 1 (HIV-1) infection and in progression to AIDS. Interleukin 18 (IL-18) is a pleiotropic proinflammatory cytokine that serves as an important regulator of immune responses. It plays a key role in induction of both Th1 and Th2 cytokines and, thereby, modulates their immune responses. Single nucleotide polymorphisms in the IL-18 gene promoter region may lead to an altered transcriptional activity and IL-18 production, and so this may account for individuals' variation to the risk of HIV-1 infection. With this perspective, the -137G/C polymorphism in the promoter region of the IL-18 gene was studied in 500 patients with HIV-1/AIDS and an equal number of sex and age matched healthy controls using sequence specific polymerase chain reaction analysis. We did not observe any significant association of the heterozygous G/C genotype with the risk of HIV-1-infection/AIDS. However, statistically significant associations of the G allele and homozygous G/G genotype of -137 G/C polymorphism of IL-18 promoter with increased risk of HIV-1/AIDS were identified. The data of the present study suggest that IL-18 -137 G allele and G/G genotype seem to be involved in the pathogenesis of HIV-1 infection among North Indians.

Polymorphisms of MTHFR and MTR genes are not related to susceptibility to childhood ALL in North India

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most worldwide common type of childhood cancer. Methylenetetrahydrofolate reductase (MTHFR) and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) participate in folate pathways and are known as critical factors for DNA integrity as well as DNA hypomethylation. The aim of this work is to investigate frequency of MTHFR (677C→T and 1298A→C) and MTR (2756A→G) polymorphisms and their interaction with respect to possible effect on risk of childhood ALL among North Indian population.

PROCEDURE

A case control study from has been conducted on bone marrow and peripheral blood samples from 125 ALL patients and 100 sex-age matched healthy controls using PCR-RFLP method.

RESULTS

No statistically significant differences were observed for different genotypes between patients and controls (p>0.05). Significant difference for the risk of ALL in individuals having genotype of MTHFR 677TT (OR=0.61, 95% CI=0.21-1.77) and MTHFR 1298CC (OR=0.56, 95% CI=0.18-1.68) was not observed. The correlation of SNP of MTR gene and risk of ALL was not observed, too.

CONCLUSIONS

The differences in distribution of possible combined genotypes of MTHFR (677C→T, 1298A→C) and MTR (2756A→G) between ALL patients and controls were statistically insignificant.

A closed form for the electrostatic interaction between two rod-like charged objects

We have calculated the electrostatic interaction between two rod-like charged objects with arbitrary orientations in three dimensions. We obtained a closed-form formula expressing the interaction energy in terms of the separation distance between the centers of the two rod-like objects, r, their lengths (denoted by 2l₁ and 2l₂) and their relative orientations (indicated by θ and φ). When the objects have the same length (2l₁ = 2l₂ = l), for particular values of separations, i.e. for r ≤ 0.8l, two types of minimum appear in the interaction energy with respect to θ. By employing the closed-form formula and introducing a scaled temperature t, we have also studied the thermodynamic properties of a 1D system of rod-like charged objects. For different separation distances, the dependence of the specific heat of the system to the scaled temperature has been studied. It is found that, for r < 0.8l, the specific heat has a maximum.

Microarray sampling-platform fabrication using bubble-jet technology for a biochip system

The fabrication of microarrays containing PCR-amplified genomic DNA extracts from mice tumors on a Zetaprobe membrane using a modified thermal ink-jet printer is described. A simple and cost-effective procedure for the fabrication of microarrays containing biological samples using a modified bubble-jet printing system is presented. Because of their mass-produced design, ink-jet printers are a much cheaper alternative to conventional spotting techniques. The usefulness of the biochip microarray platform is illustrated by the detection of human fragile histidine triad (FHIT), a tumor suppressor gene. Subcutaneous carcinomas were induced with MKN/FHIT and MKN/E4 cell lines in immunodeficient mice. Several weeks into their development, the tumors from both groups of mice were removed and subjected to DNA extraction by lysis of tissue samples. The extracted DNA samples were amplified by PCR (30 cycles) using the primers corresponding to nucleotides 2 to 18 of the FHIT sequence. The resulting solution was transferred to the individual reservoirs of a three-color cartridge from a conventional thermal ink-jet printer (HP 694C), and arrays were printed on to a Zetaprobe membrane. After spotting, these membranes were used in a hybridization assay, using fluorescent probes, and detected with a biochip.

Application of an antibody biochip for p53 detection and cancer diagnosis

Detection of the p53 tumor suppressor gene is important in early cancer diagnostics because alterations in the gene have been associated with carcinogenic manifestations in several tissue types in humans. We have developed an antibody-based detection instrument, the biochip, to detect the presence of the anti-p53 antibody in human serum. The design of this highly integrated detector system is based on miniaturized phototransistors having multiple optical sensing elements, amplifiers, discriminators, and logic circuitry on an IC board. The system utilizes laser excitation and fluorescence signals to detect complex formation between the p53 monoclonal antibody and the p53 antigen. Recognition antibodies are immobilized on a nylon membrane platform and incubated in solutions containing antigens labeled with Cy5, a fluorescent cyanine dye. Subsequently, this membrane is placed on the detection platform of the biochip and fluorescence signal is induced using a 632.8-nm He-Ne laser. Using this immuno-biochip, we have been able to detect binding of the p53 monoclonal antibody to the human p53 cancer protein in biological matrices. The performance of the integrated phototransistors and amplifier circuits of the biochip, previously evaluated through measurement of the signal output response for various concentrations of fluorescein-labeled molecules, have illustrated the linearity of the microchip necessary for quantitative analysis. The design of this biochip permits sensitive, selective and direct measurements of a variety of antigen-antibody formations at very low concentrations. Furthermore, the acquisitions of the qualitative and quantitative results are accomplished rapidly, in about 15 min. These features demonstrate the potential of this antibody-based biochip for simple, rapid and early biomedical diagnostics of cancer.

Estrogenic and DNA-damaging activity of Red No. 3 in human breast cancer cells

Exposure to pesticides, dyes, and pollutants that mimic the growth promoting effects of estrogen may cause breast cancer. The pesticide DDT and the food colorant Red No. 3 were found to increase the growth of HTB 133 but not estrogen receptor (ER) negative human breast cells (HTB 125) or rat liver epithelial cells (RLE). Red No. 3, beta-estradiol, and DDT increase ER site-specific DNA binding to the estrogen response element in HTB 133 cells and increase cyclin-dependent kinase 2 activity in MCF-7 breast cancer cells. Site-specific DNA binding by p53 in RLE, HTB 125, HTB 133, and MCF-7 cells was increased when they were treated with Red No. 3, which suggests that cellular DNA was damaged by this colorant. Red No. 3 increased binding of the ER from MCF-7 cells to the estrogen-responsive element. Consumption of Red No. 3, which has estrogenlike growth stimulatory properties and may be genotoxic, could be a significant risk factor in human breast carcinogenesis.

DDT mimicks estradiol stimulation of breast cancer cells to enter the cell cycle

Estrogens play a critical role in the etiology of found breast cancer. Estradiol promotes the growth of breast cancer cells in vivo and in vitro. Exogenous estrogens in both the environment and in the human diet increase the growth of breast cancer cells in vitro. A role for xenoestrogens in breast cancer etiology has been proposed but remains controversial. We examined the effects of the xenoestrogenic pesticide 1,1,1-trichloro-2,2-bis(chlorophenyl)ethane (DDT) on estrogen-receptor (ER)-positive MCF-7 and T-47D human breast cancer cells as well as on ER-negative HS 578Bst breast cancer cells and rat liver cells. Estradiol and DDT were found to increase the growth of MCF-7 cells in the presence of insulin. The activity of cyclin-dependent kinase (Cdk)2 increased in growth-arrested T-47D and MCF-7 cells treated with beta-estradiol or DDT. The steroidal antiestrogen ICI 182,780 prevented both growth and Cdk2 activation induced by estradiol or DDT. Increased phosphorylation of Cdk2 and the retinoblastoma protein (pRb1O5) was observed in ER-positive cells treated with DDT or estradiol. Cdk2 activity was not affected by DDT or estradiol in ER-negative HS 578Bst breast cancer cells or in rat liver epithelial cells. Cyclin D1 protein synthesis was increased by DDT and estradiol in MCF-7 cells. DDT and estradiol-induced ER-dependent transcriptional activation of estrogen response elements (EREs) in stably transfected MVLN cells, and ERE activation by low doses of DDT was increased by insulin. These findings suggest that DDT can stimulate breast cancer cells to enter into the cell cycle by directly affecting key regulatory elements. The relative potency of DDT in inducing cell-cycle progression appears to be only 100-300 times less than that of estradiol when measured in the presence of insulin. Therefore, the cancer risks associated with DDT exposure may be greater than first thought, especially when additional mitogenic stimuli are present.

Carcinogenic potential of benzene and toluene when evaluated using cyclin-dependent kinase activation and p53-DNA binding

Benzene is carcinogenic, whereas toluene is thought to have little carcinogenic potential. Benzene and toluene were found to activate cyclin-dependent kinase 2 in rat liver epithelial (RLE) and HL60 cells. pRb105 was hyperphosphorylated in RLE cells treated with either solvent. Kinase activation and subsequent hyperphosphorylation of pRb105 and p53 by benzene or toluene may be responsible for their growth promotional effects, but it does not account for increased potential of benzene to induce cancer. Therefore, we examined the ability of these solvents to increase p53-DNA site-specific binding in RLE cells. Benzene increased p53-DNA site-specific DNA binding in RLE cells compared to control levels or the effects of toluene. Increased p53-DNA site-specific binding by benzene may be caused by damage to cellular DNA. If so, although both solvents appear to have promotional activity, the increased potential of benzene to damage DNA may be responsible to the difference in the ability of benzene to cause cancer.

Transforming growth factor-beta 1 as a signal for induction of cell death by apoptosis

Cell death by apoptosis is a major determinant of growth of normal tissues and tumours. The present study aimed to elucidate signal factors involved in its regulation. Epithelial cells in control liver, during regression of cyproterone acetate induced liver hyperplasia, in liver (pre)neoplasia and in uterus undergoing apoptosis in vivo show immunostaining for transforming growth factor beta 1 (TGF-beta 1) as detected by anti-pre(266-278) TGF-beta 1 antibodies. Positive immunostaining is also seen in a few intact cells of hyperplastic, regressing liver apparently preparing for apoptosis, but is virtually not found in hepatocytes of normal or growing liver nor in cells undergoing death by necrosis. Recombinant latency associated protein (rLAP, dimer of the pro-region non-covalently associated with the mature region) complex and mature TGF-beta 1 induce apoptosis in isolated hepatocytes cultured in vitro. These findings suggest an involvement of TGF-beta 1 in the induction of apoptosis in certain epithelia in vivo.

Characterization of a complex chromosomal rearrangement maps the locus for in vitro complementation of xeroderma pigmentosum group D to human chromosome band 19q13

Microcell-mediated chromosome transfer (MMCT) is a powerful genetic technique that permits the transfer of a single chromosome from one mammalian cell to another. The utility of MMCT for gene mapping strategies is critically dependent on the careful characterization of the chromosomes being transferred. We have recently reported the identification of a single rearranged human chromosome, designated Tneo, which corrects the UV sensitivity and excision repair defect of cells of xeroderma pigmentosum genetic complementation group D (XP-D) in culture (Flejter WL et al., Proc Natl Acad Sci USA 89:261-265, 1992). Additionally, those studies demonstrated a role for the excision repair cross-complementing 2 (ERCC2) gene in the observed phenotypic correction. We now report the results of detailed conventional and molecular cytogenetic characterization of the complementing Tneo chromosome. This analysis revealed a complex rearrangement involving material from human chromosomes 16, 17, and 19. Characterization of deletions of Tneo which retained or lost XP-D complementing ability mapped the gene responsible for phenotypic correction to a small region of the terminal q-arm of this chromosome. This region includes the previously described human DNA repair gene cluster located in the region 19q13.2-q13.3, a result consistent with the notion that the in vitro correction of XP-D cells by the Tneo chromosome is rendered by the ERCC2 locus. The data illustrate the potential value of detailed cytogenetic characterization of a human chromosome present in a somatic cell hybrid, even when that material involves complex rearrangements.

Effects of sympathetic innervation on size of myocytes in embryonic rat heart cultured in oculo

Embryonic rat myocardium cultured in the anterior eye chamber of an adult rat increases in mass and differentiates into mature myocardium by most morphological criteria [1]. When sympathetic innervation of grafted heart tissue was prevented by superior cervical ganglionectomy (SCGx), growth of the grafts was severely compromised. The present study used morphometric methods to examine the contribution of myocyte size to the differential growth of grafts in sympathetically denervated and intact eye chambers. For this purpose, atria or ventricles from 12-day gestation rat hearts were grafted into sympathetically denervated and intact eye chambers of male host rats. Tissue was harvested after either 2 or 8 weeks in oculo. Myocyte diameter and the ratio of cytoplasmic area to nuclear area increased between 2 and 8 weeks in oculo in both atrial and ventricular grafts. In these unloaded heart grafts, estimated myocyte size did not differ between atrial and ventricular myocytes. Grafts into sympathetically innervated and denervated eye chambers did not differ in myocyte diameter or in the ratio of cytoplasmic to nuclear area, suggesting that myocyte size cannot explain the smaller mass of grafts in sympathetically denervated eye chambers. Thus, it is likely that other factors such as myocyte proliferation, myocyte survival or altered tissue composition underlie the lesser growth of grafts not innervated by sympathetic nerves.

Induction of dermal and subcutaneous inflammation by recombinant cachectin/tumor necrosis factor (TNF alpha) in the mouse

The ability of cachectin/tumor necrosis factor (TNF alpha) to induce acute dermal and subcutaneous inflammation was examined in a murine model. A number of other proteins, and diluent alone were examined as controls. After subcutaneous injection into the mouse footpad, recombinant human TNF alpha (rHuTNF alpha) induced acute inflammation with an initial marked dermal and subcutaneous neutrophil infiltrate by approximately 3 h, with a peak between 4 and 24 h and resolution by 79 h. Recombinant interleukin-2, cytochrome c, and heat-inactivated rHuTNF alpha induced negligible inflammation. Recombinant human lymphotoxin (TNF beta), another control protein, also induced acute inflammation in our system. Because TNF alpha and TFN beta are partially homologous, they may be acting through a similar mechanism. This pro-inflammatory effect of TNF alpha may result from chemotactic activity as well as by induction of secondary mediators. Inflammation induced by TNF alpha was partially suppressed by indomethacin treatment, suggesting that products of the cyclo-oxyganase pathway may mediate a portion of the inflammation involved. Five daily injections of rHuTNF alpha into the mouse footpad resulted in a predominantly mononuclear infiltrate and focal fibrosis. These results suggest that TNF alpha may be an important mediator of acute inflammation in vivo and might provide a signal for the production of collagen.

Epidermal cells in activation of suppressor lymphocytes: further characterization

Intravenous administration of hapten-coupled, high-density (density greater than 1.077) epidermal cells (HD-EC) to mice results in the appearance of transferable splenic T suppressor (Ts) cells as assayed in adoptive transfer experiments. Depletion of I-A bearing cells from the HD-EC population before hapten coupling prevents these cells from inducing Ts cell formation, whereas depletion of Thy-1-bearing cells from the HD-EC cell preparation has no effect. When HD-EC are adhered to glass for 2 hr, the ability to induce Ts cell formation resides in the adherent population. Exposure of HD-EC to a dose of ultraviolet radiation (UVR) that largely abrogates the ability of hapten-coupled EC to immunize mice for a DTH response does not affect the ability of these cells to activate Ts cells. Treatment of mice with i.p. administration of 20 mg/kg of cyclophosphamide 2 days before EC harvesting abrogates the ability of HD-EC from these mice to induce Ts cell formation. HD-EC from B10.A(3R) (I-Jb) but not B10.A(5R) (I-Jk) mice induce Ts cell formation in B10.A(3R) mice, demonstrating that the ability to do so is restricted by the I-J locus. Transmission electron microscopy of adherent HD-EC populations demonstrated that two cell types were present. One type had the characteristics of keratinocytes; the other was monocyte-like and resembled Langerhans cells or indeterminate cells in many aspects. Immunoelectron microscopy revealed this second cell type to bear I-A/I-E antigen. These cells were T-200 positive and Mac-1 negative by immunoperoxidase staining. Extensive examination by light and electron microscopy failed to reveal any dermal components in the EC populations; however, a very small degree of dermal contamination cannot be excluded. Thus, EC that activate afferent-acting Ts cells are high-density, I-A+, Thy-1-, I-J restricted, glass adherent, and functionally UVR resistant and cyclophosphamide sensitive.

Epidermal cells in activation of suppressor lymphocytes: further characterization

Intravenous administration of hapten-coupled, high-density (density greater than 1.077) epidermal cells (HD-EC) to mice results in the appearance of transferable splenic T suppressor (Ts) cells as assayed in adoptive transfer experiments. Depletion of I-A bearing cells from the HD-EC population before hapten coupling prevents these cells from inducing Ts cell formation, whereas depletion of Thy-1-bearing cells from the HD-EC cell preparation has no effect. When HD-EC are adhered to glass for 2 hr, the ability to induce Ts cell formation resides in the adherent population. Exposure of HD-EC to a dose of ultraviolet radiation (UVR) that largely abrogates the ability of hapten-coupled EC to immunize mice for a DTH response does not affect the ability of these cells to activate Ts cells. Treatment of mice with i.p. administration of 20 mg/kg of cyclophosphamide 2 days before EC harvesting abrogates the ability of HD-EC from these mice to induce Ts cell formation. HD-EC from B10.A(3R) (I-Jb) but not B10.A(5R) (I-Jk) mice induce Ts cell formation in B10.A(3R) mice, demonstrating that the ability to do so is restricted by the I-J locus. Transmission electron microscopy of adherent HD-EC populations demonstrated that two cell types were present. One type had the characteristics of keratinocytes; the other was monocyte-like and resembled Langerhans cells or indeterminate cells in many aspects. Immunoelectron microscopy revealed this second cell type to bear I-A/I-E antigen. These cells were T-200 positive and Mac-1 negative by immunoperoxidase staining. Extensive examination by light and electron microscopy failed to reveal any dermal components in the EC populations; however, a very small degree of dermal contamination cannot be excluded. Thus, EC that activate afferent-acting Ts cells are high-density, I-A+, Thy-1-, I-J restricted, glass adherent, and functionally UVR resistant and cyclophosphamide sensitive.