118 research outputs found

    ENDOCRINE AND AMINO-ACID REGULATION OF LIVER MACROAUTOPHAGY AND PROTEOLYTIC FUNCTION

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    Endocrine and amino acid regulation of liver macroautophagy and proteolytic function. Am, J. Physiol. 266 (Gastrointest. Liver Physiol. 29): G118-G122, 1994.-Regulation of liver macroautophagy and protein degradation by hormones and direct regulatory amino acids were studied in male 2-mo-old Sprague-Dawley albino rats with the use of the antilipolytic agent 3,5'-dimethylpyrazole (DMP; 12 mg/kg body wt ip) as a stimulatory agent. Injection of DMP decreased glutamine plasma levels and glutamine release from the perfused liver. Autophagic vacuoles were observed in the pericanalicular area of liver cells after 30 min. Levels and release of other regulatory amino acids did not exhibit any significant decrease but subsequently increased. Intraperitoneal administration of glutamine inhibited the proteolytic response. In conclusion, these studies demonstrate that in vivo induction and control of liver macroautophagy and protein degradation by the physiological mechanism (i.e., by shortage of nutrients) involve unbalanced and asynchronous changes in the levels of selected direct regulatory amino acids (i.e., a decrease in glutamine and a subsequent increase in leucine and tyrosine levels)

    Insufficient adaptive capability of pancreatic endocrine function in dexamethasone-treated ageing rats.

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    This study was aimed at exploring the capability of the pancreatic endocrine adaptive mechanisms of ageing Sprague-Dawley rats to counteract the metabolic challenge induced by the prolonged administration of dexamethasone (DEX) (0.13 mg/kg per day for 13 days). DEX treatment induced peripheral insulin resistance in 3-, 18- and 26-month-old rats, as indicated by the significant and persistent rise of plasma insulin levels in each age group (plasma insulin in 3-, 18- and 26-month-old rats from basal values of 4.3+/-0.8, 4.7+/-0.5 and 5.6+/-1.0 ng/ml (means+/-s.e.m.) respectively, rose to 11.9+/-1.7, 29.1+/-5.5 and 27.9+/-2.7 ng/ml respectively, after 9 days of administration). However, plasma glucose concentrations remained unchanged during the treatment in young rats, whereas they increased up to frankly diabetic levels in most 18-month-old and in all 26-month-old animals after a few days of DEX administration. Plasma free fatty acid concentrations increased 2-fold in 3- and 26-month-old rats and 4-fold in 18-month-old rats and could possibly be involved in the glucocorticoid-induced enhancement in insulin resistance, although they showed no significant correlation with glycaemic values. Incubation of pancreatic islets obtained from treated rats showed that DEX administration increased the insulin responsiveness of islets from not only younger but also older donors. However, in the islets of ageing rats, which already showed an age-dependent impairment of the sensitivity to glucose and other secretagogues, this enhancing effect was clearly attenuated with respect to the younger counterpart. Furthermore, DEX treatment depressed significantly the priming effect of glucose in islets isolated from all the three age groups. In conclusion, our results show that ageing rats are unable to counteract effectively a prolonged hyperglycaemic challenge as such induced by DEX administration. This homeostatic defect can be ascribed to the age-dependent failure of the endocrine pancreas to provide enough insulin to overcome the aggravation of an antecedent state of increased peripheral insulin resistance

    Milk cathelicidin and somatic cell counts in dairy goats along the course of lactation

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    This research communication reports the evaluation of cathelicidin in dairy goat milk for its relationship with the somatic cell count (SCC) and microbial culture results. Considering the limited performances of SCC for mastitis monitoring in goats, there is interest in evaluating alternative diagnostic tools. Cathelicidin is an antimicrobial protein involved in innate immunity of the mammary gland. In this work, half-udder milk was sampled bimonthly from a herd of 37 Alpine goats along an entire lactation and tested with the cathelicidin ELISA together with SCC and bacterial culture. Cathelicidin and SCC showed a strong correlation (r = 0.72; n = 360 milk samples). This was highest in mid-lactation (r = 0.83) and lowest in late lactation (r = 0.61), and was higher in primiparous (0.80, n = 130) than in multiparous goats (0.71, n = 230). Both markers increased with stage of lactation, but cathelicidin increased significantly less than SCC. Inaddition, peak level in late lactation was lower for cathelicidin (5.05-fold increase) than for SCC (7.64-fold increase). Twenty-one (5.8%) samples were positive to bacteriological culture, 20 for coagulase-negative staphylococci and one for Streptococcus spp.; 18 of them were positive to the cathelicidin ELISA (85.71% sensitivity). Sensitivity of SCC >500 000 and of SCC >1 000 000 cells/ml was lower (71.43 and 23.81%, respectively). Therefore, the high correlation of cathelicidin with SCC during the entire lactation, along with its lower increase in late lactation and good sensitivity indetecting intramammary infection (IMI), indicate a potential for monitoring subclinical mastitis in dairy goats. However, based on this preliminary assessment, specificity should be improved (40.41% for cathelicidin vs. 54.57 and 67.85% for SCC >500 000 and >1 000 000 cells/ml, respectively). Therefore, the application of cathelicidin for detecting goat IMI will require further investigation and optimization, especially concerning the definition of diagnostic thresholds

    Efficacy of vaccination on Staphylococcus aureus and coagulase-negative staphylococci intramammary infection dynamics in 2 dairy herds.

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    AbstractThe aim of this study was to evaluate vaccine efficacy of a commercial vaccine (Startvac, Hipra Spain) aimed at reducing intramammary infections (IMI) with Staphylococcus aureus and coagulase-negative staphylococci under field conditions. During the 21-mo duration of the study, 1,156 lactations from 809 cows were enrolled in 2 herds. During the first phase of the trial, all cows that were due to calve were vaccinated until approximately 50% of cows in the milking herd were vaccinated (at ~6mo). At that point, when 50% vaccination coverage was reached, cows that were due to calve were randomly assigned to be vaccinated or left as negative controls. Cure rate, rate of new infection, prevalence, and duration of infections were analyzed. Vaccination resulted in a moderate reduction in incidence of new staphylococcal IMI and a more pronounced reduction in duration of IMI associated with reduction of the basic reproduction ratio of Staph. aureus by approximately 45% and of coagulase-negative staphylococci by approximately 35%. The utilization of vaccine in combination with other infection-control procedures, such as excellent milking procedures, treatment, segregation, and culling of known infected cattle, will result in an important reduction in incidence and duration of intramammary staphylococcal infections

    PTX3 is up-regulated in epithelial mammary cells during S. aureus intramammary infection in goat

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    Pentraxins are a superfamily of conserved molecules with immune functions such as complement activation and opsonization. PTX3 is the prototypic long pentraxin and is produced by different cell populations after pro-inflammatory stimuli. Different studies have demonstrated the up-regulation of PTX3 during ruminant mastitis, but its role is still unknown. The aim of this study was to elucidate the role of PTX3 in the immune response to S. aureus intra-mammary infection (IMI). Given that no data are available on PTX3 expression in goat tissues, we first studied its pattern of expression  in goat normal tissues. Then we investigated the role of PTX3 during mammary infection, comparing its expression in healthy and infected blood, milk and tissues. Six healthy goats were infused with PBS in the right udder and with S. aureus in the left udder. Mammary biopsies from udders were collected 30h post infection, formalin fixed and routinely processed for microscopic evaluation or immediately stored in RNAlater. Tissue samples were collected at the slaughterhouse from healthy goats and were immediately stored in RNAlater. Blood and milk were collected from healthy and infected goats; cells from blood and milk were isolated and processed for RNA extraction or for cytospins; milk fat globules were obtained through milk centrifugation and immediately processed for RNA extraction. Total RNA from different organs, blood or milk cells, milk fat globules and mammary tissues was extracted and used as template in qPCR for PTX3. PTX3 expression was investigated by immunohistochemistry on formalin fixed paraffin embedded mammary tissue samples and on cytospins of isolated goat blood and milk cells. PTX3 mRNA was expressed with very high levels in bone marrow, mammary gland, aorta, pancreas, skin and lung. Given the high expression in the mammary gland, we investigated which cell population expressed PTX3. PTX3 was mainly expressed in the apical cytoplasmic portion of mammary gland epithelial cells, and in macrophages. During S. aureus infection PTX3 was up-regulated by epithelial cells. Macrophages and mammary secretum didn’t show PTX3 modulation, but PMNs recruited during infection were variably intensely positive. PTX3 mRNA expression was low in healthy organs and tissues of goats as has been reported indeed the molecules commonly induced after pro-inflammatory stimulation. As expected, PTX3 was constitutively expressed in bone marrow, rich in PMNs and monocytes, in aorta covered by endothelium and in the skin. PTX3 was up-regulated in epithelial mammary cells and in milk cells after S. aureus infection, demonstrating that it represents a first line of immune defense in goat udder. No modulation was observed in macrophages, in the secretum and in the ductal epithelial cells. Further experiments are needed to elucidate the role of PTX3 in the pathogenesis of S. aureus infection

    Chemotherapy-induced nausea and vomiting in daily clinical practice: a community hospital-based study

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    Background Chemotherapy-induced nausea and vomiting (CINV) are major adverse effects of cancer chemotherapy. This study investigated: (1) the impact of CINV on patients' health-related quality of life (HRQL) in daily clinical practice; (2) the association between patient characteristics and type of antiemetics and CINV; and (3) the role of CINV in physicians' decisions to modify antiemetic treatment. Patients and methods This prospective, multicenter study was conducted in nine general hospitals in the Netherlands. During three consecutive chemotherapy cycles, patients used a diary to record episodes of nausea, vomiting and antiemetic use. For each cycle, these ratings were made 1 day prior to and 7 days after having received chemotherapy. The influence of CINV on patients' HRQL was evaluated with the Functional Living Index-Emesis (FLIE) questionnaire at day 6 of each treatment cycle. (Changes in) antiemetic use were recorded by the treating nurse. Patient inclusion took place between May 2005 and May 2007. Results Two hundred seventy-seven patients were enrolled in the study. Acute and delayed nausea during the first treatment cycle was reported by 39% and 68% of the patients, respectively. The comparable figures for acute and delayed vomiting were 12% and 23%. During the first and subsequent treatment cycle, approximately one-third of the patients indicated that CINV had a substantial impact on their daily lives. Female patients and younger patients reported significantly more CINV than male and older patients. At all treatment cycles, patients receiving treatment with moderately emetogenic chemotherapy, containing anthracycline, reported more acute nausea than patients receiving highly emetogenic chemotherapy. Acute vomiting was associated significantly with change in (i.e., additional) antiemetic treatment. Delayed CINV did not influence antiemetic treatment. Conclusion CINV continues to be a problem that adversely affects the daily lives of patients. CINV is worse in women and in younger patients. In daily clinical practice, acute CINV, but not delayed CINV, results in changes in antiemetic treatment. In view of the effects of not only acute, but also delayed CINV on daily life, more attention should be paid to adjustment of antiemetic treatment to cover CINV complaints, later during the chemotherapy cycle

    Prolonged fixed dose rate infusion of gemcitabine with autologous haemopoietic support in advanced pancreatic adenocarcinoma

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    This study aimed to define the maximum-tolerated dose (MTD) of fixed dose rate (FDR) of gemcitabine (2′-2′-difluorodeoxycitidine) infusion with circulating haemopoietic progenitor support and to evaluate the activity of the treatment. Secondary end points were pharmacokinetic of gemcitabine and difluorodeoxyuridina (dFdU) measured at first course and the activity andexpression profile of cytidine deaminase (CdA) on circulating mononuclear cells. Patients with advanced pancreatic carcinoma received escalating dose of gemcitabine 10 mg m−2 min−1 every 2 weeks with circulating haemopoietic progenitor support. First dose level was 3000 mg m−2 and the doses were increased by 500 mg m−2 until MTD. In all, 23 patients were enrolled. Toxicities were mild or moderate; the only patient treated at 7000 mg m−2 died because of toxicity; therefore; the MTD was established at 6500 mg m−2. The overall response rate was 22.2%. The AUC of gemcitabine showed a dose-dependent increase, while the AUC of dFdU reached a plateau at 4500 mg m−2. A significant relationship was found between the AUC of dFdU and CdA expression and activity (P<0.05). Moreover, progression rate and survival were significantly related to CdA expression and activity levels. The activity of high-dose gemcitabine is not superior to that reported with less intensive FDR schedules. The predictive role of CdA expression and activity on outcome deserves further investigation

    A phase II trial of gemcitabine plus carboplatin in advanced transitional cell carcinoma of the urothelium

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    <p>Abstract</p> <p>Background</p> <p>Recent studies have demonstrated the effectiveness of cisplatin-based combinations in patients with advanced transitional cell carcinoma(TCC) of the urothelium. Concern over cisplatin toxicity instigated a search for alternative regimens. The aim of the study was to evaluate the activity and tolerability of gemcitabine plus carboplatin combination as first-line treatment in patients with advanced transitional cell carcinoma of the urothelium.</p> <p>Methods</p> <p>Patients with advanced TCC were treated with gemcitabine 1200 mg/m<sup>2 </sup>on days 1 and 8 and carboplatin area under the concentration-time curve(AUC) 5 on day 1 every 21 days.</p> <p>Results</p> <p>Out of 41 patients, thirty-nine were evaluable for efficacy and 41 for toxicity. A median of 5 cycles (range 1–6) was administered. Overall response rate was 46.2% (95% confidence interval: 32–65%) including 10.3% complete responses and 35.9% partial responses. The median time to progression and median overall survival were 7.5 months (95% confidence interval: 6.6–8.4 months) and 13.6 months (95% confidence interval: 10.2–17.0 months), respectively. Grade 3/4 neutropenia, anemia and thrombocytopenia were observed in 36.6%, 26.8, and 24.4% of patients, respectively. Non-hematological toxicity was generally mild. Grade 3 vomiting occurred in 1 (2.4%) patients.</p> <p>Conclusion</p> <p>The gemcitabine plus carboplatin combination is active in advanced TCC with acceptable toxicity and needs to be evaluated further and compared with other non-cisplatin-containing regimens.</p> <p>Trial registration</p> <p>ISRCTN88259320</p
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