Preliminary method for profiling volatile organic compounds in breath that correlate with pulmonary function and other clinical traits of subjects diagnosed with cystic fibrosis: a pilot study

Cystic fibrosis (CF) is characterized by chronic respiratory infections which progressively decrease lung function over time. Affected individuals experience episodes of intensified respiratory symptoms called pulmonary exacerbations (PEx) which accelerate pulmonary function decline and decrease survival. There is no standard classification for PEx, which results in treatments that are heterogeneous. Improving PEx classification and management is a significant priority for people with CF. Previous studies have shown volatile organic compounds (VOCs) in exhaled breath can be used as biomarkers because they are products of metabolic pathways dysregulated by different diseases. To provide insights on PEx classification and other clinical factors, exhaled breath was collected from subjects with CF, with some experiencing PEx and others at baseline. Exhaled breath was collected in Tedlar bags during tidal breathing for VOC analysis by solid phase microextraction coupled to gas chromatography-mass spectrometry. Statistical significance testing between quantitative and categorical clinical variables displayed percent-predicted forced expiratory volume in one second (FEV1pp) was decreased in subjects experiencing PEx. VOCs correlating with other clinical variables (body mass index, age, use of highly effective modulator therapies, and need for antibiotics) were also explored. VOCs correlating to potential confounding variables were removed and analyzed by regression for correlations with FEV1pp measurements. The VOC with the highest correlation with FEV1pp (3,7-dimethyldecane) also gave the lowest p-value when comparing subjects at baseline and during PEx. Receiver operator characteristic curves showed 3,7-dimethyldecane had a higher ability to classify PEx (area under the curve (AUC) = 0.91) relative to FEV1pp values at collection (AUC = 0.83). However, normalized ΔFEV1pp values had the highest capability to distinguish PEx (AUC = 0.93). These results show that exhaled VOCs may be a source of biomarkers for various clinical traits of CF, including PEx, that should be explored in larger sample cohorts and validation studies.

Efficacy of Endoscopic Submucosal Dissection for Superficial Gastric Neoplasia in a Large Cohort in North America

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) is a widely accepted treatment option for superficial gastric neoplasia in Asia, but there are few data on outcomes of gastric ESD from North America. We aimed to evaluate the safety and efficacy of gastric ESD in North America.

METHODS

We analyzed data from 347 patients who underwent gastric ESD at 25 centers, from 2010 through 2019. We collected data on patient demographics, lesion characteristics, procedure details and related adverse events, treatment outcomes, local recurrence, and vital status at the last follow up. For the 277 patients with available follow-up data, the median interval between initial ESD and last clinical or endoscopic evaluation was 364 days. The primary endpoint was the rate of en bloc and R0 resection. Secondary outcomes included curative resection, rates of adverse events and recurrence, and gastric cancer-related death.

RESULTS

Ninety patients (26%) had low-grade adenomas or dysplasia, 82 patients (24%) had high-grade dysplasia, 139 patients (40%) had early gastric cancer, and 36 patients (10%) had neuroendocrine tumors. Proportions of en bloc and R0 resection for all lesions were 92%/82%, for early gastric cancers were 94%/75%, for adenomas and low-grade dysplasia were 93%/ 92%, for high-grade dysplasia were 89%/ 87%, and for neuroendocrine tumors were 92%/75%. Intraprocedural perforation occurred in 6.6% of patients; 82% of these were treated successfully with endoscopic therapy. Delayed bleeding occurred in 2.6% of patients. No delayed perforation or procedure-related deaths were observed. There were local recurrences in 3.9% of cases; all occurred after non-curative ESD resection. Metachronous lesions were identified in 14 patients (6.9%). One of 277 patients with clinical follow up died of metachronous gastric cancer that occurred 2.5 years after the initial ESD.

CONCLUSIONS

ESD is a highly effective treatment for superficial gastric neoplasia and should be considered as a viable option for patients in North America. The risk of local recurrence is low and occurs exclusively after non-curative resection. Careful endoscopic surveillance is necessary to identify and treat metachronous lesions.

Endoscopic Submucosal Dissection in North America: A Large Prospective Multicenter Study

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) in Asia has been shown to be superior to endoscopic mucosal resection (EMR) and surgery for the management of selected early gastrointestinal cancers. We aimed to evaluate technical outcomes of ESD in North America.

METHODS

We conducted a multicenter prospective study on ESD across 10 centers in the United States and Canada between April 2016 and April 2020. End points included rates of en bloc resection, R0 resection, curative resection, adverse events, factors associated with failed resection, and recurrence post-R0 resection.

RESULTS

Six hundred and ninety-two patients (median age, 66 years; 57.8% were men) underwent ESD (median lesion size, 40 mm; interquartile range, 25-52 mm) for lesions in the esophagus (n = 181), stomach (n = 101), duodenum (n = 11), colon (n = 211) and rectum (n = 188). En bloc, R0, and curative resection rates were 91.5%, 84.2%, and 78.3%, respectively. Bleeding and perforation were reported in 2.3% and 2.9% of the cases, respectively. Only 1 patient (0.14%) required surgery for adverse events. On multivariable analysis, severe submucosal fibrosis was associated with failed en bloc, R0, and curative resection and higher risk for adverse events. Overall recurrence was 5.8% (31 of 532) at a mean follow-up of 13.3 months (range, 1-60 months).

CONCLUSIONS

In this large multicenter prospective North American experience, we demonstrate that ESD can be performed safely, effectively, and is associated with a low recurrence rate. The technical resection outcomes achieved in this study are in line with the current established consensus quality parameters and further support the implementation of ESD for the treatment of select gastrointestinal neoplasms; ClinicalTrials.gov, Number: NCT02989818.

Pedal gangrene in a patient with COVID-19 treated with prone positioning and extracorporeal membrane oxygenation

Many patients hospitalized with coronavirus disease 2019 are treated with venovenous extracorporeal membrane oxygenation and prone positioning to optimize oxygenation. However, this combination can result in lower extremity tissue necrosis, especially without adequate offloading. We report the case of a 31-year-old man who required mechanical ventilation and venovenous extracorporeal membrane oxygenation secondary to complications from coronavirus disease 2019, and subsequently developed pedal dry gangrene. The patient was discharged and healed without requiring an amputation. Our institution has since revised the prone positioning protocol to address offloading the lower extremities and feet.

Mechanical stimulations can inhibit local and remote tumor progression by downregulating WISP1

Mechanical stimulations can prevent bone loss, but their effects on the tumor-invaded bone or solid tumors are elusive. Here, we evaluated the effect of knee loading, dynamic loads applied to the knee, on metastasized bone and mammary tumors. In a mouse model, tumor cells were inoculated to the mammary fat pad or the proximal tibia. Daily knee loading was then applied and metabolic changes were monitored mainly through urine. Urine samples were also collected from human subjects before and after step aerobics. The result showed that knee loading inhibited tumor progression in the loaded tibia. Notably, it also reduced remotely the growth of mammary tumors. In the urine, an altered level of cholesterol was observed with an increase in calcitriol, which is synthesized from a cholesterol derivative. In urinary proteins, knee loading in mice and step aerobics in humans markedly reduced WNT1-inducible signaling pathway protein 1, WISP1, which leads to poor survival among patients with breast cancer. In the ex vivo breast cancer tissue assay, WISP1 promoted the growth of cancer fragments and upregulated tumor-promoting genes, such as Runx2, MMP9, and Snail. Collectively, the present preclinical and human study demonstrated that mechanical stimulations, such as knee loading and step aerobics, altered urinary metabolism and downregulated WISP1. The study supports the benefit of mechanical stimulations for locally and remotely suppressing tumor progression. It also indicated the role of WISP1 downregulation as a potential mechanism of loading-driven tumor suppression.

Skeletal loading regulates breast cancer-associated osteolysis in a loading intensity-dependent fashion

Osteocytes are mechanosensitive bone cells, but little is known about their effects on tumor cells in response to mechanical stimulation. We treated breast cancer cells with osteocyte-derived conditioned medium (CM) and fluid flow-treated conditioned medium (FFCM) with 0.25 Pa and 1 Pa shear stress. Notably, CM and FFCM at 0.25 Pa induced the mesenchymal-to-epithelial transition (MET), but FFCM at 1 Pa induced the epithelial-to-mesenchymal transition (EMT). This suggested that the effects of fluid flow on conditioned media depend on flow intensity. Fluorescence resonance energy transfer (FRET)-based evaluation of Src activity and vinculin molecular force showed that osteopontin was involved in EMT and MET switching. A mouse model of tumor-induced osteolysis was tested using dynamic tibia loadings of 1, 2, and 5 N. The low 1 N loading suppressed tumor-induced osteolysis, but this beneficial effect was lost and reversed with loads at 2 and 5 N, respectively. Changing the loading intensities in vivo also led to changes in serum TGFβ levels and the composition of tumor-associated volatile organic compounds in the urine. Collectively, this study demonstrated the critical role of intensity-dependent mechanotransduction and osteopontin in tumor-osteocyte communication, indicating that a biophysical factor can tangibly alter the behaviors of tumor cells in the bone microenvironment.

Pitavastatin slows tumor progression and alters urine-derived volatile organic compounds through the mevalonate pathway

Bone is a frequent site of metastasis from breast cancer, and a desirable drug could suppress tumor growth as well as metastasis-linked bone loss. Currently, no drug is able to cure breast cancer-associated bone metastasis. In this study, we focused on statins that are known to inhibit cholesterol production and act as antitumor agents. After an initial potency screening of 7 U.S. Food and Drug Administration-approved statins, we examined pitavastatin as a drug candidate for inhibiting tumor and tumor-induced bone loss. In vitro analysis revealed that pitavastatin acted as an inhibitor of tumor progression by altering stress to the endoplasmic reticulum, down-regulating peroxisome proliferator-activated receptor γ, and reducing Snail and matrix metalloproteinase 9. In bone homeostasis, it blocked osteoclast development by suppressing transcription factors c-Fos and JunB, but stimulated osteoblast mineralization by regulating bone morphogenetic protein 2 and p53. In a mouse model, pitavastatin presented a dual role in tumor inhibition in the mammary fat pad, as well as in bone protection in the osteolytic tibia. In mass spectrometry-based analysis, volatile organic compounds (VOCs) that were linked to lipid metabolism and cholesterol synthesis were elevated in mice from the tumor-grown placebo group. Notably, pitavastatin-treated mice reduced specific VOCs that are linked to lipid metabolites in the mevalonate pathway. Collectively, the results lay a foundation for further investigation of pitavastatin's therapeutic efficacy in tumor-induced bone loss, as well as VOC-based diagnosis of tumor progression and treatment efficacy.-Wang, L., Wang, Y., Chen, A., Teli, M., Kondo, R., Jalali, A., Fan, Y., Liu, S., Zhao, X., Siegel, A., Minami, K., Agarwal, M., Li, B.-Y., Yokota, H. Pitavastatin slows tumor progression and alters urine-derived volatile organic compounds through the mevalonate pathway.

Safety and efficacy of endoscopic submucosal dissection for rectal neoplasia: a multicenter North American experience

Background and aims  Rectal lesions traditionally represent the first lesions approached during endoscopic submucosal dissection (ESD) training in the West. We evaluated the safety and efficacy of rectal ESD in North America. Methods  This is a multicenter retrospective analysis of rectal ESD between January 2010 and September 2018 in 15 centers. End points included: rates of en bloc resection, R0 resection, adverse events, comparison of pre- and post-ESD histology, and factors associated with failed resection. Results  In total, 171 patients (median age 63 years; 56 % men) underwent rectal ESD (median size 43 mm). En bloc resection was achieved in 141 cases (82.5 %; 95 %CI 76.8-88.2), including 24 of 27 (88.9 %) with prior failed endoscopic mucosal resection (EMR). R0 resection rate was 74.9 % (95 %CI 68.4-81.4). Post-ESD bleeding and perforation occurred in 4 (2.3 %) and 7 (4.1 %), respectively. Covert submucosal invasive cancer (SMIC) was identified in 8.6 % of post-ESD specimens. There was one case (1/120; 0.8 %) of recurrence at a median follow-up of 31 weeks; IQR: 19-76 weeks). Older age and higher body mass index (BMI) were predictors of failed R0 resection, whereas submucosal fibrosis was associated with a higher likelihood of both failed en bloc and R0 resection. Conclusion  Rectal ESD in North America is safe and is associated with high en bloc and R0 resection rates. The presence of submucosal fibrosis was the main predictor of failed en bloc and R0 resection. ESD can be considered for select rectal lesions, and serves not only to establish a definitive tissue diagnosis but also to provide curative resection for lesions with covert advanced disease.

Density Gradient Centrifugation and Electron Microscopic Characterization of Subcellular Fractions from Human Blood Platelets

Homogenized human blood platelets have been fractionated by centrifugation in Ficoll and sucrose density gradients. The different fractions were examined by electron microscopy.

Although Ficoll allows for the separation of very distinct zones, its ability to form complexes with cellular components made sucrose the preferable gradient. Sucrose, in spite of its unfavorable osmotic effect, allows for an acceptable fractionation of platelet components.

Cross-Selectivity Enhancement of Poly(vinylidene fluoride-hexafluoropropylene)-Based Sensor Arrays for Detecting Acetone and Ethanol

Two methods for cross-selectivity enhancement of porous poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)/carbon black (CB) composite-based resistive sensors are provided. The sensors are tested with acetone and ethanol in the presence of humid air. Cross-selectivity is enhanced using two different methods to modify the basic response of the PVDF-HFP/CB sensing platform. In method I, the adsorption properties of PVDF-HFP/CB are altered by adding a polyethylene oxide (PEO) layer or by treating with infrared (IR). In method II, the effects of the interaction of acetone and ethanol are enhanced by adding diethylene carbonate (DEC) or PEO dispersed in DEC (PEO/DEC) to the film. The results suggest the approaches used in method I alter the composite ability to adsorb acetone and ethanol, while in method II, they alter the transduction characteristics of the composite. Using these approaches, sensor relative response to acetone was increased by 89% compared with the PVDF-HFP/CB untreated film, whereas sensor relative response to ethanol could be decreased by 57% or increased by 197%. Not only do these results demonstrate facile methods for increasing sensitivity of PVDF-HFP/CB film, used in parallel they demonstrate a roadmap for enhancing system cross-selectivity that can be applied to separate units on an array. Fabrication methods, experimental procedures and results are presented and discussed.

Notizen: Über eine modifizierte Technik der Säulenchromatographie

Eine modifizierte Technik der Säulenchromatographie unter Verwendung von Rohren, die sich in der Längsrichtung öffnen lassen, erlaubt die rasche und materialsparende Trennung von Substanzgemischen.

[Patient participation in medical decision making within an integrated health care system in Germany: results of a controlled cohort study]

An integrated health care project called "Gesundes Kinzigtal" was conducted in a rural area in Germany. As part of the project, physicians were trained and other measures were taken to enhance patient involvement in medical decision making. As part of the external evaluation, various effects regarding patient involvement in medical decision making, patient involvement and information preference, decision confidence, patient satisfaction with ambulatory care and patient quality of life were examined. The data were gathered by means of a questionnaire on an annual basis between 2007 and 2009. Effects were compared between patients who were participating in the integrated care project and two control groups. Analyses are based on the data of 1,205 patients. Over time all outcomes decreased slightly, except for information preference and physical quality of life. No statistically significant intervention effects on patient involvement in medical decision making or any other outcome variable could be found. The intensity of the training was presumably too low to establish an enduring change in the physician-patient interaction.

Gestational flu exposure induces changes in neurochemicals, affiliative hormones and brainstem inflammation, in addition to autism-like behaviors in mice

The prevalence of neurodevelopmental disorders such as autism is increasing, however the etiology of these disorders is unclear and thought to involve a combination of genetic, environmental and immune factors. A recent epidemiological study found that gestational viral exposure during the first trimester increases risk of autism in offspring by twofold. In mice gestational viral exposures alter behavior of offspring, but the biological mechanisms which underpin these behavioral changes are unclear. We hypothesized that gestational viral exposure induces changes in affiliative hormones, brainstem autonomic nuclei and neurotransmitters which are associated with behavioral alterations in offspring. To address this hypothesis, we exposed pregnant mice to influenza A virus (H3N2) on gestational day 9 and determined behavioral, hormonal and brainstem changes in male and female offspring. We found that gestational flu exposure induced dose-dependent alterations in social and aggressive behaviors (p≤0.05) in male and female offspring and increases in locomotor behaviors particularly in male offspring (p≤0.05). We found that flu exposure was also associated with reductions in oxytocin and serotonin (p≤0.05) levels in male and female offspring and sex-specific changes in dopamine metabolism. In addition we found changes in catecholaminergic and microglia density in brainstem tissues of male flu exposed offspring only (p≤0.05). This study demonstrates that gestational viral exposure induces behavioral changes in mice, which are associated with alterations in affiliative hormones. In addition we found sex-specific changes in locomotor behavior, which may be associated with sex-specific alterations in dopamine metabolism and brainstem inflammation. Further investigations into maternal immune responses are necessary to unravel the molecular mechanisms which underpin abnormal hormonal, immune and behavioral responses in offspring after gestational viral exposure.

Prevalence of high-risk human papilloma virus among women with hepatitis C virus before liver transplantation

BACKGROUND

We sought to assess the prevalence and risk factors for high-risk human papillomavirus (HPV) infection among female liver transplant (LT) candidates. Traditional health screening before LT listing has included Pap smear and is typically carried out by the patient's local provider. The prevalence of high-risk HPV in this population has not been studied.

METHODS

With Institutional Review Board approval, 62 LT candidates received a liquid-based Pap smear with high-risk HPV testing as part of their pre-transplant evaluation by a single provider. Clinical variables included age, ethnicity, insurance status, prior Pap smear, and HPV results, HPV risk factors including age of first intercourse, number of lifetime partners, last sexual activity, smoking, birth control pill use, history of sexually transmitted infections, human immunodeficiency virus status, immunosuppressive medication, medical diagnoses, prescribed medications, and history of hepatitis A, B, C, or D.

RESULTS

The 62 women had a median age of 56 years, and 39% had high-risk behavior known to be associated with HPV. Ten of 62 patients (16.1%) had high-risk HPV at baseline screening, 5 of whom had atypical cytology. All of the patients who were positive for high-risk HPV had an etiology of hepatitis C virus (HCV) as the underlying cause of liver disease, with the majority (90%) having no history of high-risk behavior for HPV. In contrast, all patients with high-risk behavior who were HCV negative were HPV negative. Fisher's exact test demonstrated a statistically significant relationship between HPV and HCV; odds ratio = 24.4, 95% confidence interval, 1.4, 438.7, P-value = 0.0013. None of the other potential risk factors were associated with HPV in this cohort.

CONCLUSIONS

In this study, we provide evidence of a strong association between HCV and HPV in LT candidates, which has not been previously reported. HPV positivity was observed in non-sexually active women, suggesting a reactivation of dormant HPV. An association between hepatitis C and high-risk HPV could involve impairment of T-cell function by hepatitis C. These data support close surveillance in women's health screening for LT candidates. Further studies to characterize immune responses in these patients will be in order.

Structural phase transition in LiFeSi2O6 from ab initio calculations

The changes in crystal structure of LiFeSi(2)O(6) induced by the phase transition between the high-temperature C2/c and low-temperature P2(1)/c phase are studied using the density functional theory. For both monoclinic phases, the phonon dispersion curves and phonon density of states are calculated. The infrared absorption coefficients are obtained and analyzed in both structural phases of LiFeSi(2)O(6). The soft mode inducing the phase transition is revealed at the Z point of the Brillouin zone of the high-symmetry C2/c phase. The pressure dependence of the soft mode is studied and the mechanism of the structural phase transition in LiFeSi(2)O(6) is discussed.

[Patients as customers? The term "customer" in the perception of medical students at the end of their university training]

In the preceding decades a new perspective on the role of patients in the health-care system has gained ground, considering patients not merely as "suffering persons" but additionally as "customers". Physicians, however, tend to disagree with this approach because of the economic connotation of the term customer. Until now, there is only poor evidence of whether students of medicine - who are going to work as physicians in the future - agree or disagree with that approach and whether they are ready to accept patients as customers. In the following study students of medicine were interviewed on their perspectives towards that approach, in particular on their attitudes towards the idea of "the patient as customer", the appropriateness of the term consumer in different clinical settings and sectors of health care, the implementation of consumer orientation in clinical routine, and their favoured model of physician-patient relationship.As the study could not build upon data of prior similar studies, a quantitative and qualitative cross-sectional study with a descriptive-explorative design was conducted. Using a semi-standardised questionnaire, 313 medical students (response rate: 95%) were interviewed in Spring 2010. At the time of the survey, the students were enrolled at the faculty of medicine at Freiburg University, Germany, and were in their last semester which immediately preceded their exam.The future physicians do not consider patients primarily as customers. More than 80% of the respondents "absolutely" or "largely" supported the idea that patients are considerably more than customers. The analysis of the qualitative data of the study shows different results. Here, more statements were made that patients could equally be seen as customers (449 students supported this idea, 298 did not). Statements contradicting the customer approach referred mostly to the asymmetry of the physician-patient relationship and the special role of the patient. The highest level of acceptance of the customer approach was found in classical service settings such as pharmacies, the lowest level in emergency medical aid. According to medical students, a consumer orientation has been realised in different health service areas in correspondingly different degrees: On top of the list are plastic surgery clinics, followed by private health insurances and homeopathic clinics. A minority of medical students predict the implementation of consumer orientation in the emergency medical aid. Future physicians consider their relationship to patients largely as a relationship between a healing person and a person seeking help rather than a relationship between a service provider and a customer.Considering recent developments in the organisation of medical services and health services in general, it becomes increasingly important to know what kind of 'service behaviour' patients expect from their doctors and other health providers. Obviously, it is not self-evident for medical students to perceive their future patients as customers and to act as customer-oriented 'service providers'. In view of this, the faculties of medicine at universities - which provide professional training to students of medicine - should be aware of the challenge to 'socialise' their students so that they can keep up with patients' expectations.

Concentration of dissolved amino acids from saline waters by ligand-exchange chromatography

Amino acids dissolved in salt solutions may be concentrated and removed from the solution by ligand exchange on copper-Chelex 100 resin. Competing inorganic ligands do not interfere, and ion exchange with cations does not occur; thus loss of metal ion from this column is avoided. To test the potentiality of ligand exchange for chromatography, the type and nature of the dissolved amino compounds in sea water were investigated. The data revealed that the bulk of the dissolved amino compounds is present in a combined rather than a free state.

Chloroplast DNA transcripts are encapsidated by tobacco mosaic virus coat protein

Preparations of tobacco mosaic virus contain pseudovirions, particles resembling virions but containing host rather than viral RNA. The encapsidated host RNA was found to be composed of discrete-sized species derived from a large portion of the chloroplast genome except that very little, if any, ribosomal RNA is present. Pseudovirions contain the same chloroplast DNA transcripts as those detected in extracts from uninfected leaves, although not always in the same relative amounts. Several strains of tobacco mosaic virus were tested and all were found to contain pseudovirions, with the U2 strain containing more than the others.

Peripheral and central mediators of lipopolysaccharide induced suppression of defensive rage behavior in the cat

Based upon recent findings in our laboratory that cytokines microinjected into the medial hypothalamus or periaqueductal gray (PAG) powerfully modulate defensive rage behavior in cat, the present study determined the effects of peripherally released cytokines following lipopolysaccharide (LPS) challenge upon defensive rage. The study involved initial identification of the effects of peripheral administration of LPS upon defensive rage by electrical stimulation from PAG and subsequent determination of the peripheral and central mechanisms governing this process. The results revealed significant elevation in response latencies for defensive rage from 60 to 300 min, post LPS injection, with no detectable signs of sickness behavior present at 60 min. In contrast, head turning behavior elicited by stimulation of adjoining midbrain sites was not affected by LPS administration, suggesting a specificity of the effects of LPS upon defensive rage. Direct administration of LPS into the medial hypothalamus had no effect on defensive rage, suggesting that the effects of LPS were mediated by peripheral cytokines rather than by any direct actions upon hypothalamic neurons. Complete blockade of the suppressive effects of LPS by peripheral pretreatment with an Anti-tumor necrosis factor-alpha (TNFalpha) antibody but not with an anti- interleukin-1 (IL-1) antibody demonstrated that the effects of LPS were mediated through TNF-alpha rather than through an IL-1 mechanism. A determination of the central mechanisms governing LPS suppression revealed that pretreatment of the medial hypothalamus with PGE(2) or 5-HT(1A) receptor antagonists each completely blocked the suppressive effects of LPS, while microinjections of a TNF-alpha antibody into the medial hypothalamus were ineffective. Microinjections of -Iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) benzamide monohydrochloride (p-MPPI) into lateral hypothalamus (to test for anatomical specificity) had no effect upon LPS induced suppression of defensive rage. The results demonstrate that LPS suppresses defensive rage by acting through peripheral TNF-alpha in periphery and that central effects of LPS suppression of defensive rage are mediated through PGE(2) and 5-HT(1A) receptors in the medial hypothalamus.

A minimal model for hepatic fatty acid balance during fasting: application to PPAR alpha-deficient mice

The purpose of this study is to identify the hierarchy of importance amongst pathways involved in fatty acid (FA) metabolism and their regulators in the control of hepatic FA composition. A modeling approach was applied to experimental data obtained during fasting in PPARalpha knockout (KO) mice and wild-type mice. A step-by-step procedure was used in which a very simple model was completed by additional pathways until the model fitted correctly the measured quantities of FA in the liver. The resulting model included FA uptake by the liver, FA oxidation, elongation and desaturation of FA, which were found active in both genotypes during fasting. From the model analysis we concluded that PPARalpha had a strong effect on FA oxidation. There were no indications that this effect changes during the fasting period, and it was thus considered to be constant. In PPARalpha KO mice, FA uptake was identified as the main pathway responsible for FA variation in the liver. The models showed that FA were oxidized at a constant and small rate, whereas desaturation of FA also occurred during fasting. The latter observation was rather unexpected, but was confirmed experimentally by the measurement of delta-6-desaturase mRNA using real-time quantitative PCR (QPCR). These results confirm that mathematical models can be a useful tool in identifying new biological hypotheses and nutritional routes in metabolism.