Survival of Salmonella spp. and pathogenic Escherichia coli in food matrices and its relevance in the development of proficiency testing samples

Monitoring of food products by government agencies for their compliance to regulatory limits is an essential step in controlling foodborne outbreaks. For monitoring purposes, an extensive setup of the surveillance system is used which involves ISO 17025:2017 accredited laboratories for food testing. Participation in proficiency testing (PT) programs is a requirement of ISO 17025:2017 which ensures data accuracy and analyst competency. Participation in PT schemes is costly for laboratories in developing countries as most of the commercial suppliers are situated in the USA & Europe. The literature or data available on creation of microbiological proficiency testing is scanty as much of the data available with commercial suppliers are trade secret and there is only 0.06% of research articles available in Scopus database on the said topic. In this review article, an attempt is made to understand the factors impacting the survival of two important foodborne pathogens i.e., Escherichia coli & Salmonella spp. by extracting information available from growth studies and root cause analysis of various food safety incidents and recalls. Utilization of this information in the development of PT samples is discussed in this review article along with a focus on the availability of PT samples and associated ISO standards to formulate homogeneous and stable PT samples. This review article elaborates on the focus areas which can be considered by PT providers (PTP), for example, initial inoculum level and preparation, strain type, microbial growth phase, the impact of different types of food matrices which includes low moisture food, antimicrobial components, pH, presence of competitor microbes, and environmental conditions involving storage temperature, time, and relative humidity. These focus areas can be used to successfully create PT samples by PTP in developing countries.

Review on development of assigned value microbiological reference materials used in food testing

Evolving testing methods in food Microbiology have resulted in the need for different types of microbiological reference materials. Based on the research articles available in this area, it is evident that development has been quite substantial in chemical testing compared to Microbiology. The primary reason could be the ease of spiking, and recovery in chemical RM as compared to microbiological RM. A significant challenge faced in recovery and stability during the development of quantitative microbiological RM depends on temperature, type of microbiological media used, method of analysis including reconstitution method, interference due to antimicrobial agents in food matrices, and competitor microorganisms present in higher numbers then the target microorganisms. Most of the research papers published on microbiological reference materials are contributed by developed economies were in the information related to complex food matrices are limited. Further analysis of different International Depository Agencies under the Budapest treaty indicates that there are only three institutes based in Europe providing quantitative or assigned value RM. This, in turn, highlights the scarcity in the availability of quantitative RM in Microbiology. This article provides a global overview of the availability of microbiological RM, microbial preservation techniques, protective agents, and elaboration on developing different formats of microbiological RM used in food testing.

Lurasidone-Induced Manic Switch in an Adolescent with Bipolar I Disorder: a Case Report

Lurasidone is used for treatment of bipolar depression in adults and adolescents. Lurasidone-associated manic switch has been reported in adults but not yet in adolescents. We report a case of lurasidone-induced manic switch in a male adolescent treated for bipolar I depression. Five days after adding lurasidone to his regimen (sodium valproate and olanzapine), our patient became manic with psychotic features. After discontinuation of lurasidone, he was stabilised with electroconvulsive therapy, and the medication was switched to a lithium-quetiapine combination. This case highlights the potential risk of lurasidone-induced manic switch in adolescents with bipolar depression.

Relationship between leadership support and operational excellence in health care sector: A study of Indian health care managers

BACKGROUND AND OBJECTIVE

Leadership communicates purpose and innovative ways to thrive for performance. Leadership support influences and impacts operational excellence in the health sector as a patient-centered operation, with effective management, excellence framework, challenges and constraints, teamwork and value stream mapping. It is hypothesized that: (1) perceived leadership support will positively correlate with perceived operational excellence (Patient-centered Operations, Effective Resource Management, Excellence framework, Eliminating Challenges or Constraints, Team Work, Value Stream Mapping) and (2) the correlation would be highest with Patient-centered Operations. The aim of this study was to examine the relationship between leadership support and operational excellence in the health care sector among a selected group of healthcare managers.

MATERIALS AND METHOD

A correlation study between leadership support and operational excellence was designed for a group of health care managers (n=80) from eight hospitals in Kerala, South India. The selection of executives was from NABH accredited hospitals from districts with a minimum of four NABH accredited hospital. A survey was sent to a selected study sample. The respondents were cooperative and provided responses on perceived leadership support for operational excellence.

RESULTS

Factors of leadership support correlated to operational excellence.

CONCLUSION

In the health care sector, leadership support for patient-centered operations helps achieve operational excellence.

Atorvastatin modulates drug transporters and ameliorates nicotine-induced testicular toxicity

We studied the changes in mRNA expressions of influx and efflux transporters, blood-testis-barrier proteins (BTB) and key apoptotic genes in the testis of rats coadministered with nicotine and atorvastatin. Rats were divided into four groups: (i) control, (ii) atorvastatin (10 mg/kg b.wt), (iii) nicotine (0.6 mg/kg b.wt) and (iv) atorvastatin (10 mg/kg b.wt) + nicotine (0.6 mg/kg b.wt). Atorvastatin was given by oral intubation and nicotine by intraperitoneal injection. After 60 days of treatment, expressions of key apoptotic genes involved in both intrinsic and extrinsic pathways; solute carrier influx transporters SLCOB1, SLC22A1 and efflux transporter ABCB1 associated with transport of atorvastatin and nicotine, and proteins of BTB were assayed. Nicotine administration activated apoptosis and downregulated SLCOB1, which transport atorvastatin. Atorvastatin administration suppressed apoptotic pathway and downregulated SLC22A1, transporter of nicotine. Coadministration of atorvastatin with nicotine downregulated expressions of apoptotic genes. The combined administration of atorvastatin and nicotine reduced the influx of both atorvastatin and nicotine and enhanced the efflux of these drugs thereby altering the microenvironment of testis and improving testicular function. We conclude that atorvastatin-mediated alterations of BTB and drug transporters might have played a significant role in ameliorating nicotine-induced testicular toxicity.

Stereotactic body radiation therapy for early-stage primary lung cancer, is an active breath coordinator necessary? An audit from a tertiary cancer care center

CONTEXT

The hypofractionated stereotactic body radiation therapy (SBRT) has emerged as a safe and effective treatment modality for early-stage nonsmall cell lung carcinoma.

AIMS

An audit SBRT in primary lung cancer treated in our center with and without an active breath coordinator (ABC) was undertaken to evaluate its impact on target volumes and clinical outcomes.

SETTINGS AND DESIGN

This was an observational study.

MATERIALS AND METHODS

Nine patients with lung carcinoma were treated from January 2014 to August 2016. Five patients were simulated using ABC and four patients with free breathing. Volumetric modulated arc therapy plans were generated using Monaco treatment planning software. Three patients were treated with a dose of 54 Gy in three fractions and six patients with a dose of 48 Gy in four fractions.

STATISTICAL ANALYSIS USED

The statistical analysis was performed using Kaplan-Meier survival.

RESULTS

The mean planning target volumes (PTV) in ABC and free breathing groups were 42.19cc and 60.17cc, respectively. The mean volume of lung receiving 20, 10, and 5 Gy (V20, V10and V5) in ABC group were 5.37cc, 10.49cc, and 18.45cc whereas in free breathing 6.63cc, 12.74cc, and 20.64cc, respectively. At a median follow-up of 18 months, there were three local recurrences. No significant toxicity occurred in our series.

CONCLUSION

Our initial results show that SBRT is well tolerated with good local control. Although the PTV volume and irradiated normal lung volume was higher in this group compared to ABC group, this did not translate to any added clinical toxicity.

Mechanisms underlying the formation of the amygdalar fear memory trace: A computational perspective

Recent experimental and modeling studies on the lateral amygdala (LA) have implicated intrinsic excitability and competitive synaptic interactions among principal neurons (PNs) in the formation of auditory fear memories. The present modeling studies, conducted over an expanded range of intrinsic excitability in the network, revealed that only excitable PNs that received tone inputs participate in the competition. Strikingly, the number of model PNs integrated into the fear memory trace remained constant despite the much larger range considered, and model runs highlighted several conditioning-induced tone responsive characteristics of the various PN populations. Furthermore, these studies showed that although excitation was important, disynaptic inhibition among PNs is the dominant mechanism that keeps the number of plastic PNs stable despite large variations in the network's excitability. Finally, we found that the overall level of inhibition in the model network determines the number of projection cells integrated into the fear memory trace.

Virgin coconut oil supplementation ameliorates cyclophosphamide-induced systemic toxicity in mice

Virgin coconut oil (VCO) is an unrefined kernal oil, prepared from Cocos nucifera L., having substantial nutritional and medicinal value. Experimental studies have suggested its antioxidant, anti-inflammatory, immunostimulatory and hypolipidemic effects. The present study assesses its effect on formalin-induced chronic inflammation and cyclophosphamide (CTX)-induced systemic toxicity in murine models. Oral administration of VCO effectively reduced formalin-induced paw oedema in mice with more or less similar efficacy as that of diclofenac. The CTX-induced hike in blood urea, creatinine, thiobarbituric acid reactive substances (TBARS) and liver marker enzymes in mice was marginally decreased by VCO (8 g/kg body weight) ingestion orally. The liver and kidney catalase, superoxide dismutase and glutathione peroxidase activities, together with cellular glutathione and TBARS levels, were found to be improved in these animals. Overall the study reveals the protective efficacy of VCO against secondary toxicity induced by CTX possibly through its antioxidant and anti-inflammatory properties.

Santalbic acid from quandong kernels and oil fed to rats affects kidney and liver P450

Kernels of the plant Santalum acuminatum (quandong) are eaten as Australian 'bush foods'. They are rich in oil and contain relatively large amounts of the acetylenic fatty acid, santalbic acid (trans-11-octadecen-9-ynoic acid), whose chemical structure is unlike that of normal dietary fatty acids. When rats were fed high fat diets in which oil from quandong kernels supplied 50% of dietary energy, the proportion of santalbic acid absorbed was more than 90%. Feeding quandong oil elevated not only total hepatic cytochrome P450 but also the cytochrome P450 4A subgroup of enzymes as shown by a specific immunoblotting technique. A purified methyl santalbate preparation isolated from quandong oil was fed to rats at 9% of dietary energy for 4 days and this also elevated cytochrome P450 4A in both kidney and liver microsomes in comparison with methyl esters from canola oil. Santalbic acid appears to be metabolized differently from the usual dietary fatty acids and the consumption of oil from quandong kernels may cause perturbations in normal fatty acid biochemistry.

Effect of tonsillectomy on aso-titre

136 children below the age of 15 suffering from chronic tonsillitis were screened. 56 patients who showed a raised ASO titre above 200iu/ml were selected for this study. All of them underwent tonsillectomy. ASO titre estimation was done after 1 month;62% after 3 months;78% after 6 months and 88% after 1 year.

Role of sensory input distribution and intrinsic connectivity in lateral amygdala during auditory fear conditioning: a computational study

We propose a novel reduced-order neuronal network modeling framework that includes an enhanced firing rate model and a corresponding synaptic calcium-based synaptic learning rule. Specifically, we propose enhancements to the Wilson-Cowan firing-rate neuron model that permit full spike-frequency adaptation seen in biological lateral amygdala (LA) neurons, while being sufficiently general to accommodate other spike-frequency patterns. We also report a technique to incorporate calcium-dependent plasticity in the synapses of the network using a regression scheme to link firing rate to postsynaptic calcium. Together, the single-cell model and the synaptic learning scheme constitute a general framework to develop computationally efficient neuronal networks that employ biologically realistic synaptic learning. The reduced-order modeling framework was validated using a previously reported biophysical conductance-based neuronal network model of a rodent LA that modeled features of Pavlovian conditioning and extinction of auditory fear (Li et al., 2009). The framework was then used to develop a larger LA network model to investigate the roles of tone and shock distributions and of intrinsic connectivity in auditory fear learning. The model suggested combinations of tone and shock densities that would provide experimental estimates of tone responsive and conditioned cell proportions. Furthermore, it provided several insights including how intrinsic connectivity might help distribute sensory inputs to produce conditioned responses in cells that do not directly receive both tone and shock inputs, and how a balance between potentiation of excitation and inhibition prevents stimulus generalization during fear learning.

Exchange bias effect in partially oxidized amorphous Fe-Ni-B based metallic glass nanostructures

The magnetic properties of amorphous Fe-Ni-B based metallic glass nanostructures were investigated. The nanostructures underwent a spin-glass transition at temperatures below 100 K and revealed an irreversible temperature following the linear de Almeida-Thouless dependence. When the nanostructures were cooled below 25 K in a magnetic field, they exhibited an exchange bias effect with enhanced coercivity. The observed onset of exchange bias is associated with the coexistence of the spin-glass phase along with the appearance of another spin-glass phase formed by oxidation of the structurally disordered surface layer, displaying a distinct training effect and cooling field dependence. The latter showed a maximum in exchange bias field and coercivity, which is probably due to competing multiple equivalent spin configurations at the boundary between the two spin-glass phases.

Ethical aspects of the Revised National Tuberculosis Control Programme

This paper identifies some ethical concerns regarding the Revised National Tuberculosis Control Programme (RNTCP). Only 10% of those with chest symptoms visiting public health facilities get specific treatment as they are diagnosed with TB. The remaining 90% who suffer from non-TB diseases are not given scientific treatment. This compartmental approach denies treatment to millions of people with chest symptoms. It has also eroded the popularity of public health facilities. Second, though 87% of those diagnosed on the basis of x-ray alone are unlikely to have TB, such unethical wrong diagnoses continue to be carried out under the TB programme. Still worse, the RNTCP's expectation that only half of TB cases should be smear positive effectively permits up to 50% of diagnoses to be wrong. The actual extent of wrong diagnosis is even higher as the majority of people with chest symptoms first visit private health facilities which base their diagnosis almost exclusively on radiological examination. Third, though 25% to 33% of TB cases get cured spontaneously, and at least two-thirds were cured even with incomplete treatment, the RNTCP insists on full treatment for all TB cases. This over-treatment is unethical, wasteful and also tantamount to scientific dishonesty. Studies to identify different categories of cases (those needing full treatment, short treatment or no treatment) have not been attempted. The introduction (under the RNTCP) of the "success rate"in preference to the well recognised "cure rate" was unethical and unwarranted. "Crying wolf" over Multiple Drug Resistant (MDR) TB to justify DOTS when there is no apparent alarming increase in the incidence of initial MDR tuberculosis cases is also questionable. Other ethical concerns about the RNTCP include the irrational choice of districts leading to exclusion of those that need the services most; exclusion of diagnosed patients from the DOTS scheme, and exclusion from treatment on non-medical grounds. Such exclusions can be up to 58% of TB cases.

Novel mouse model for studying role of ER-nongenomic actions in breast cancer

Abstract #601

Back ground: Estradiol (E2) and estrogen receptor (ER) signaling play a key role in development and progression of breast cancer. ER signaling is complex, involves coregulatory proteins and the status of ER coregulators in tumor cells plays an important role in hormonal responsiveness and tumor progression. In addition, ER also participates in non-genomic signaling events in the cytoplasm, however the significance of non-genomic signaling in mammary tumorigenesis remain unknown. PELP1/MNAR is novel ER coregulator that participates in ER genomic and non-genomic actions. PELP1 expression is deregulated in breast tumors and in a subset of tumors PELP1 is predominantly localized in the cytoplasm. Since PELP1 cytoplamsic localization promotes excessive activation of Src and AKT pathways, we hypothesized that PELP1 mediated excessive activation of ER-nongenomic functions may play a role tumorigenesis. To test this, we have generated MMTV-PELP1cyto TG model that uniquely express PELP1 in the cytoplasm of mammary glands that mimics the pathological situation of PELP1 localization seen breast cancer.
 Methods: As a means of targeting the expression of the PELP1 transgene to the mammary gland, we placed the PELP1cyto cDNA under the control of the MMTV promoter. PELP1 transgene integration was verified by PCR and expression levels by Western and IHC in each founder line. Whole-mount preparations and IHC analysis was performed using Tg and age controlled wild type littermates from different developmental stages. Total protein extracts of mammary gland were used for western blot analysis of nongenomic signaling components.
 Results: Preliminary analysis of mammary gland from PELP-cyto mice showed hyperplasia, increased proliferation as analyzed by PCNA staining. Mammary tumors were observed as early as 32 weeks. No spontaneous mammary tumors were found in the wild type cohort. Pathological analysis revealed that these tumor masses represent full blown mammary adenocarcinomas. Mammary tumors showed excessive activation of nongenomic signaling including activation of Src and AKT pathways. A clear induction of aromatase expression was found in PELP1 tumors compared with the wild-type that showed no aromatase expression in the mammary gland.
 Discussion: We have established and characterized a transgenic mouse model that mimics deregulated ER-nongenomic signaling. Our results suggest that PELP1 is a proto-oncogene and demonstrates its in vivo tumorigenic potential. PELP1 driven tumors are ER+ve, express aromatase, thus provide an interesting in vivo model for studying ER-mediated tumorigenesis and to study effect of local E2 on ER-mediated tumorigenesis.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 601.

Potential role of estrogen receptor coregulator in mitosis

Abstract #5036

Background: Estrogen stimulates breast tissue to increase cell divisions (mitosis) and is implicated in breast cancer progression. ER action is complex and requires functional interactions with coregulators. Proline-, glutamic acid-, and leucine-rich protein (PELP)-1, also known as modulator of nongenomic actions of estrogen receptor (MNAR), is a novel nuclear receptor (ER) coregulator with multitude of functions. Emerging evidence suggest that PELP1 expression is deregulated in breast cancer and serves as a scaffolding protein that couples various signaling complexes with estrogen receptor. In this study we found that ER coregulator PELP1 plays a novel role in mitosis.
 Material and Methods: To understand the mechanism by which ER coregulator PELP1 contribute to breast cancer progression, we have utilized small RNA interference methodology and established breast cancer model cells that stably express PELP1-shRNA (MCF7-PELP1shRNA). FACS analysis was used to determine the cell cycle status of the model cells. Using confocal microscopy, immunoprecipitation, in vitro kinase assays, site directed mutagenesis and Western analysis using phospho-antibodies we studied the mechanism and significance of PELP1 signaling in mitotic progression. We also developed PELP1 siRNA nanoparticles and used them as well as CDK1 inhibitors in cell proliferation studies.
 Results: Down regulation of PELP1 expression resulted in decreased estrogen mediated cell proliferation, delayed mitotic progression and induced accumulation of mitotic cells. Interestingly, PELP1 depleted cells also exhibited multinucleation. Western analysis of various markers of mitotic progression revealed a delay in the kinetics of G2M initiation and progression. Confocal analysis revealed colocalization of CDK1 and PELP1 in G2M. Immunoprecipitation assays demonstrate that endogenous CDK1 form functional complex with PELP1 and Src kinase during mitosis. Using deletion and mutagenesis approach, we have mapped the putative CDK1 phosphorylation sites on PELP1. Down regulation of PELP1 or overexpression of PELP1 mutants (that cannot be phosphorylated by CDK1), reduces the magnitude of Src activation, which is an essential driving force for timely progression of M phase. PELP1 siRNA nanoparticles alone or in combination with CDK1 inhibitors have shown to significantly reduce the proliferation of breast cancer cells and showed increased response in tamoxifen resistant breast cancer cells.
 Discussion: These results suggest that ER coregulator PELP1 play a novel role in G2M progression. Since PELP1 expression is deregulated in breast cancer, PELP1 ability to regulate mitosis could contribute to the progression of cancer by causing genomic instability through the deregulation of mitosis. Taken together our findings suggest that estrogen can promote neoplasia using coregulators by two distinct mechanisms (1) Coregulator induction of target genes and (2) Coregulator mediated actions in mitosis. ER coregulator PELP1 play multiple roles in Estrogen mediated neoplasia, and thus represent a target for novel therapeutic breast cancer strategies by forming the “next generation” of antimitotic drugs.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5036.

Computational model of extracellular glutamate in the nucleus accumbens incorporates neuroadaptations by chronic cocaine

Chronic cocaine administration causes instability in extracellular glutamate in the nucleus accumbens that is thought to contribute to the vulnerability to relapse. A computational framework was developed to model glutamate in the extracellular space, including synaptic and nonsynaptic glutamate release, glutamate elimination by glutamate transporters and diffusion, and negative feedback on synaptic release via metabotropic glutamate receptors (mGluR2/3). This framework was used to optimize the geometry of the glial sheath surrounding excitatory synapses, and by inserting physiological values, accounted for known stable extracellular, extrasynaptic concentrations of glutamate measured by microdialysis and glutamatergic tone on mGluR2/3. By using experimental values for cocaine-induced reductions in cystine-glutamate exchange and mGluR2/3 signaling, and by predicting the down-regulation of glutamate transporters, the computational model successfully represented the experimentally observed increase in glutamate that is seen in rats during cocaine-seeking. This model provides a mathematical framework for describing how pharmacological or pathological conditions influence glutamate transmission measured by microdialysis.

Comparison of some modeling and control issues for a flexible two link manipulator

The nonlinear dynamics of a flexible two link manipulator presents a challenging modeling and control problem with its lumped actuator dynamics coupled with distributed link dynamics. Issues related to modeling uncertainty and control robustness as well as a good understanding of the experimental issues are essential for advanced modeling and control for such systems. This paper reports some of the advanced modeling, control, and experimental issues for a flexible two link manipulator, including some novel approaches developed by the authors.

Reduction of Salt (NaCl) Losses During the Manufacture of Cheddar Cheese

The objective of this study was to evaluate the effects of cheese-making technologies, including homogenization of cream, ultrafiltration, and vacuum condensing of milk, on the retention of salt in Cheddar cheese. One part of pasteurized, separated milk (0.58% fat) was ultrafiltered (55 degrees C, 16.0% protein), another vacuum condensed (12.5% protein), and the third was not concentrated. Cheddar cheese was manufactured using 6 treatments by standardizing unconcentrated milk to a casein-to-fat ratio of 0.74 with unhomogenized 35% fat cream (C), homogenized (6.9 MPa/3.5 MPa) 35% fat cream (CH), ultrafiltered milk and unhomogenized cream (UF), ultrafiltered milk and homogenized cream (UFH), condensed milk and unhomogenized cream (CM), and condensed milk and homogenized cream (CMH). Treatments C and CH had 3.7% fat and 3.5% protein, and the respective values for the remaining treatments were 4.9 and 4.6. The milled curd was dry salted at 2.7% by weight. The salt content of the cheeses receiving homogenization treatment was higher at 1.83 and 1.70% for CH and UFH, respectively, compared with their corresponding controls at 1.33%. The salt content in cheeses from CMH was 1.64% and was not affected by homogenization. Salt retention in C increased from 41.7 to 59.2% in CH, and in UF it increased from 42.5 to 54.5% in UFH. There was a corresponding decrease in the salt content of whey from these cheeses.

A neural network approach to identifying adolescent adjustment

This study examined the relationship between the quality of adjustment in adolescents and a set of psychiatric diagnoses, personality traits, parental bonding, and social support variables. One hundred fifty adolescents were administered the Millon Adolescent Personality Inventory, the Parental Bonding Questionnaire, the Social Support Questionnaire, and the Diagnostic Interview for Children and Adolescents. A neural network approach was then utilized, and it was found that several of the variables (e.g., Major Depressive Disorder, Conduct Disorder, and Societal Conformity) had a significant role in classifying adolescents into three groups: maladjusted, nominally adjusted, and well-adjusted.

Beneficial effects of garlic (Allium sativum Linn) on rats fed with diets containing cholesterol and either of the oil seeds, coconuts or groundnuts

Feeding of 2% cholesterol diet increased lipid parameters in serum and tissues of rats during a period of one month. In addition to the above, lipid peroxidation also increased and activities of certain enzymes were significantly altered in the tissues. Similar changes were also observed to a greater extent with diets containing 40% by weight of coconut kernel or groundnut with and without 2% cholesterol. The enzymes studied were HMGCoA reductase, AST, ALT and ALP in tissues and serum as the case may be. In general the atherogenic effects were observed more with groundnut containing diets than those with coconut. Even though the oil from the former is mostly unsaturated and that from the latter is mostly saturated, these analytical criteria do not relate to their atherogenic effects. When 5% garlic was incorporated with any of the high fat diets, the lipid parameters, their peroxidation and alterations in enzyme activities were significantly decreased. These results show that garlic contains some principles that counteract the atherogenicity of the above oil seeds.

Over-expression of MSG1 transcriptional co-activator increases melanin in B16 melanoma cells: a possible role for MSG1 in melanogenesis

MSG1 is a 27 kDa nuclear protein that is expressed strongly in melanotic B16 melanoma cells but very weakly in amelanotic B16 cells. Transient expression of B16 cells with an expression vector for MSG1 resulted in an increase in levels of the enzyme dopachrome tautomerase but not tyrosinase, as detected by western blotting. Stable transfection of B16 melanoma cells with plasmids containing the full length MSG1 or its deletion mutants, however, generated cell lines that showed an increase in levels of tyrosinase, dopachrome tautomerase and cellular melanin when compared with control transfected cells. Our results suggest that MSG1 plays an important role in melanogenesis, by regulating the levels of the enzymes of the pigmentary system via tyrosinase and dopachrome tautomerase.

Three-way analysis of fluorescence spectra of polycyclic aromatic hydrocarbons with quenching by nitromethane

The application of trilinear decomposition (TLD) to the analysis of fluorescence excitation-emission matrices of mixtures of polycyclic aromatic hydrocarbons (PAHs) is described. The variables constituting the third-order tensor are excitation wavelength, emission wavelength, and concentration of a fluorescence quencher (nitromethane). The addition of a quencher to PAH mixtures selectively reduces the fluorescence intensity of mixture components according to the Stern-Volmer equation. TLD allows the three-way matrix to be decomposed to give unique solutions for the excitation spectrum, emission spectrum, and quenching profiles for each component. The availability of spectra and calculated Stern-Volmer constants can aid in the identification of unknown components. Preprocessing of the data to correct for Rayleigh/Raman scatter and primary absorption by the quencher is necessary. Both three-component (anthracene, pyrene, 1-methylpyrene) and four-component (fluoranthene, anthracene, pyrene, 2,3-benzofluorene) synthetic mixtures are successfully resolved by TLD using quencher concentrations up to 100 mM. Results are compared using both alternating least-squares and direct trilinear decomposition algorithms. The reproducibility of extracted Stern-Volmer constants is determined from replicate experiments. To illustrate the application of TLD to a real sample, a chromatographic cut from the analysis of a light gas oil sample was used. Analysis of the TLD extracted spectra and quenching constants suggests the presence of three classes of polycyclic aromatic hydrocarbons consistent with data from a second dimension of chromatography and mass spectrometry.

Suppression of inositol phosphate release by cardiac myocytes isolated from fish oil-fed pigs

Fatty acid composition of cardiac myocytes and release of inositol phosphates in pigs fed a fish oil supplemented diet was examined. Two groups of female pigs were fed diets supplemented with either 50 g/kg diet beef tallow (as control) or 50 g/kg diet fish oil (MaxEPA) rich in n-3 fatty acids. After 6 weeks of supplementation, the pigs were anesthetized and hearts were removed. Cardiac myocytes were isolated, lipid extracted and separated into non-polar and polar lipids by thin-layer chromatography. Fatty acid composition of individual neutral and polar lipid classes were examined by gas chromatography. To study the effect of membrane phospholipid modification on the phospholipase C (PLC) mediated release of inositol phosphates, cardiac myocytes were labelled with 4 microCi/mL myo-[2-(3)H]inositol for 48 h. After stimulation with epinephrine and phenylephrine, the water soluble [3H]inositol products were extracted, separated from [3H]inositol and [3H]glycerophosphoinositol by chromatography on Dowex AG 1-X8 and quantitated by scintillation counting. Cardiac myocytes isolated from fish oil-fed pigs had higher levels of n-3 polyunsaturated fatty acid in the non-esterified fatty acid and phospholipid fraction. Similarly, these cardiac myocytes had increased level of n-3 fatty and decreased n-6 fatty acids in all the phospholipid fractions, PE, PC, P1 and PS (p < 0.05). After stimulation, the levels of [3H]inositol trisphosphate (IP3) and [3H]inositol tetrakisphosphate (IP4) in cardiac myocytes isolated from fish oil-fed pigs were significantly reduced (p < 0.05) compared to myocytes isolated from beef tallow fed-pigs. This study for the first time has utilised adult cardiac myocytes to demonstrate the effect of n-3 PUFA supplementation on cardiac myocyte phospholipid fatty acid composition and release of second messengers.

Parametric studies of human thermal mechanisms and measurements

A systematic methodology is proposed for mathematically quantifying the effects of measurement inaccuracies due to instrument uncertainty in a human calorimetry project. Human thermal mechanisms are poorly understood at the systems level and this study investigates the importance of these mechanisms quantitatively. The proposed methodology uses sensitivity derivatives combined with sensor accuracies to quantify the effect of each heat transfer mechanism contributing to the errors in the system equations. The method is applicable to any differentiable model to be validated by experimentation. To illustrate the methodology, two example cases, a reclining nude resting subject and a reclining clothed working subject, are analyzed. The calculated expected errors clearly suggest specific modifications.

Cardiac (n-3) non-esterified fatty acids are selectively increased in fish oil-fed pigs following myocardial ischemia

The effect of fish oil supplementation on the nonesterified fatty acid (NEFA) concentration and composition in the normoxic and hypoxic myocardium of pigs was examined. Two groups of female pigs (n = 7) were fed a diet supplemented with either 5 g beef tallow/kg (as control) or 5 g fish oil/kg (MaxEPA) rich in (n-3) fatty acids. After 6 wk of supplementation, the pigs were anesthetized, hearts exposed by thoracotomy followed by occlusion of the left anterior descending artery. Normoxic and hypoxic regions of the heart were examined for NEFA concentration and composition by using a combination of thin layer and gas chromatography. Nonesterified (n-6) and (n-3) fatty acid concentration and composition differed significantly between the two groups in both the normoxic and hypoxic areas of the heart. Eicosapentaenoic and docosahexaenoic acid concentration in the NEFA fraction of the normoxic myocardium were higher in the fish oil group than in the beef tallow group (P < 0.001). In the fish oil-fed pigs, the (n-3) NEFA concentration was significantly higher in the hypoxic compared to the normoxic region of the heart. The fish oil-fed group had lower levels of arachidonic acid in the NEFA fraction compared to the beef tallow-fed group, whereas the hypoxic myocardium had higher levels of arachidonic acid, regardless of the dietary fat supplementation. Despite large differences in the proportions of saturated fatty acids in the experimental diets, there was little or no difference in the saturated fatty acid content of cardiac phospholipid and NEFA fractions. Following myocardial ischemia, (n-3) fatty acids in the NEFA fractions were selectively increased in the fish oil-fed pigs, implicating the possible role of nonesterified (n-3) polyunsaturated fatty acids in the prevention of arrhythmias.

Specific modifications of phosphatidylinositol and nonesterified fatty acid fractions in cultured porcine cardiomyocytes supplemented with n-3 polyunsaturated fatty acids

Mechanisms for the antiarrhythmic effect of n-3 polyunsaturated fatty acids (PUFA) are currently being investigated using isolated cardiac myocytes. It is still not known whether the incorporation of n-3 PUFA into membrane phospholipids is a prerequisite for its protective action or if n-3 PUFA exert antiarrhythmic effects in their nonesterified form as demonstrated by recent studies. Adult porcine cardiomyocytes were grown in media supplemented with arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). After 24 h, analysis of total lipids showed that the myocytes were enriched with the respective fatty acids compared to control cells. Large proportions of all three fatty acids supplemented (69% AA, 72% DHA, and 66% EPA) remained unesterified. Fatty acid analyses of total phospholipids (PL) revealed that the incorporation of EPA and DHA, though small, was significantly different (P<0.05) from that of the control cells. The PL fraction was further separated into phosphatidylinositol (PI), phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine to study the pattern of incorporation of the fatty acids in these fractions. It became apparent that EPA and DHA were selectively incorporated into the PI fraction. This study demonstrates that in adult porcine cardiomyocytes, the n-3 PUFA supplementation selectively modulates two important lipid fractions, nonesterified fatty acid and PI, which were implicated in the mechanisms of prevention of cardiac arrhythmias.

Stress reactions of children and adolescents in war and siege conditions

OBJECTIVE

This was a study of posttraumatic stress symptoms in children and adolescents during siege conditions in Sarajevo.

METHOD

Seven hundred ninety-one students aged 7-15 years were surveyed to assess symptoms of posttraumatic stress and level of deprivation.

RESULTS

Girls reported more stress than boys. Loss of family members and deprivation of basic needs were associated with more symptoms.

CONCLUSIONS

Personal experiences of siege are related to increased stress.

Prevention of cardiac arrhythmia by dietary (n-3) polyunsaturated fatty acids and their mechanism of action

The role of marine fish oil (n-3) polyunsaturated fatty acids in the prevention of fatal ventricular arrhythmia has been established in experimental animals. Prevention of arrhythmias arising at the onset of ischemia and reperfusion is important because if untreated, they result in sudden cardiac death. Animals supplemented with fish oils in their diet developed little or no ventricular fibrillation after ischemia was induced. Similar effects have also been observed in cultured neonatal cardiomyocytes. Several mechanisms have been proposed and studied to explain the antiarrhythmic effects of fish oil polyunsaturated fatty acids, but to date, no definite mechanism has been validated. The sequence of action of these mechanisms and whether more than one mechanism is involved is also not clear. Some of the mechanisms suggested to explain the antiarrhythmic action of fish oils include the incorporation and modification of cell membrane structure by (n-3) polyunsaturated fatty acids, their direct effect on calcium channels and cardiomyocytes and their role in eicosanoid metabolism. Other mechanisms that are currently being investigated include the role of (n-3) polyunsaturated fatty acids in cell signalling mediated through phosphoinositides and their effect on various enzymes and receptors. This article reviews these mechanisms and the antiarrhythmic studies using (n-3) polyunsaturated fatty acids.

Relationship of personality, environmental, and DICA variables to adolescent hopelessness: a neural network sensitivity approach

OBJECTIVE

This study identified critical factors from a set of psychiatric diagnoses, personality traits, and family and social support variables that relate to hopelessness in adolescents.

METHOD

One hundred fifty adolescents were selected in a systematic sample from 1,700 high school students; they completed the Millon Adolescent Personality Inventory, the Parental Bonding Questionnaire, the Social Support Questionnaire, the Hopelessness Scale for Children and were interviewed by trained clinicians on the Diagnostic Interview for Children and Adolescents. Selected variables were chosen for a back-propagation neural network model and for subsequent sensitivity and statistical analysis.

RESULTS

Sensitive adolescents and adolescents with less impulse control scored high on hopelessness. Forceful adolescents were less hopeless.

CONCLUSIONS

Using the neural network models, the authors suggest that assertive training as well as group activities that increase cooperativeness may ameliorate hopelessness.

Detecting dysfunctional behavior in adolescents: the examination of relationships using neural networks

We describe a neural network that models the effect of personality, social, and environmental variables on hopelessness in adolescents. A sensitivity analysis suggests the effect that variation in each of the input variables will have on the output. Clinical implications are that health professionals can focus their attention on the variables most likely to impact upon the outcome.

Pulmonary hypertension and systemic lupus erythematosus

A combination of systemic lupus erythematosus (SLE) and fatal pulmonary hypertension occurred in a patient who, to our knowledge, had the highest pulmonary artery pressure (120/65 mm Hg) reported without any clinical or autopsy findings of pulmonary interstitial disease or vasculitis. The gradual development of pulmonary hypertension over years is a rare complication in patients with SLE.

Tuberculosis in rural South India. A study of possible trends and the potential impact of antituberculosis programmes

Data on the dynamics of the tuberculosis situation in rural South India, obtained by the National Tuberculosis Institute, Bangalore, were fed into a mathematical model. By this means predictions about the future tuberculosis situation have been made under a wide range of hypothetical assumptions.