Central role of the melanocortin-4 receptors in appetite regulation after endotoxin     

Sartin JL  Marks DL  McMahon CD  Daniel JA  Levasseur P  Wagner CG  Whitlock BK  Steele BP 《Journal of animal science》2008,86(10):2557-2567

Melanocortin-4 receptors (MC4R) are key factors in the depression of appetite during disease. This study was designed to determine the role of agouti-related protein (AgRP) in the effect of endotoxin (lipopolysaccharide, LPS) on appetite. Sheep received an intracerebroventricular injection of either saline or AgRP (0.5 nmol/kg of BW) 1 h before intravenous injection of either saline or LPS (0.6 microg/kg of BW) at time 0 and again at 4 h. Agouti-related protein prevented the reduction in feed intake due to LPS (P < 0.05). In a second experiment, AgRP gene expression was unaffected at 3 h and increased (P < 0.01) at 6 h after LPS. Immunohistochemical evidence indicated that there was an increase in the percentage of AgRP neurons with c-Fos immunoreactive nuclei 6 h after sheep were injected with LPS (P < 0.04) and a corresponding decrease in a-melanocyte-stimulating hormone neurons coexpressing c-Fos (P < 0.001). In situ hybridization provided evidence for an increase in AgRP gene expression and a decrease in proopiomelanocortin gene expression 6 h after LPS (P < 0.05). In a final experiment, physiological elevation of orexigenic agents by short-term fasting kept feed intake at the same level as controls, in spite of the presence of LPS, similar to the effects of AgRP in Exp. 1. The AgRP inhibition of the MC4R prevents appetite inhibition in response to LPS and well after LPS inhibition of feed intake, both AgRP and a-melanocyte-stimulating hormone may change in a pattern that favors appetite increases. These studies support the notion of the MC4R as a critical component of the mechanism for appetite suppression due to endotoxin.  相似文献   

Gastrointestinal pythiosis in 10 dogs from California     

Berryessa NA  Marks SL  Pesavento PA  Krasnansky T  Yoshimoto SK  Johnson EG  Grooters AM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(4):1065-1069

BACKGROUND: Pythium insidiosum is an aquatic oomycete that causes severe segmental thickening of the canine gastrointestinal (GI) tract, resulting in weight loss, vomiting, diarrhea, and death. Infection in dogs previously has been observed primarily in the southeastern United States. OBJECTIVE: To describe the clinicopathologic and epidemiologic findings associated with GI pythiosis in 10 dogs from California. METHODS: Dogs were initially identified on the basis of supportive clinical findings and routine histology. Pythiosis was confirmed in each dog with at least one of the following: immunoblot serology, enzyme-linked immunosorbent assay serology, immunohistochemistry, and culture followed by species-specific polymerase chain reaction, rRNA gene sequencing, or both. RESULTS: Between September 2003 and December 2006, GI pythiosis was confirmed in 1 dog from central California and 9 dogs that lived within a 30-mile radius of Davis, CA. Seven of 8 dogs for which environmental data were available had frequent access to flooded rice fields or other water sources. Esophageal lesions were present in 2 of 10 dogs. Common laboratory findings included eosinophilia (7/9), hypoalbuminemia (9/9), and hyperglobulinemia (8/9). Median survival time was 26.5 days (range, 0-122 days), and the disease was ultimately fatal in all 10 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: The geographic distribution of pythiosis has widened in recent years to include the western United States. Factors that may have contributed to this change include altered rice-farming practices and landscape irrigation. Veterinarians in California should be familiar with the clinicopathologic features associated with GI pythiosis to aid in early diagnosis and effective treatment.  相似文献   

Carotenoid content of pandanus fruit cultivars and other foods of the Republic of Kiribati     

Englberger L  Aalbersberg W  Dolodolotawake U  Schierle J  Humphries J  Iuta T  Marks GC  Fitzgerald MH  Rimon B  Kaiririete M 《Public health nutrition》2006,9(5):631-643

BACKGROUND: Kiribati, a remote atoll island country of the Pacific, has serious problems of vitamin A deficiency (VAD). Thus, it is important to identify locally grown acceptable foods that might be promoted to alleviate this problem. Pandanus fruit (Pandanus tectorius) is a well-liked indigenous Kiribati food with many cultivars that have orange/yellow flesh, indicative of carotenoid content. Few have been previously analysed. AIM: This study was conducted to identify cultivars of pandanus and other foods that could be promoted to alleviate VAD in Kiribati. METHOD: Ethnography was used to select foods and assess acceptability factors. Pandanus and other foods were analysed for beta- and alpha-carotene, beta-cryptoxanthin, lutein, zeaxanthin, lycopene and total carotenoids using high-performance liquid chromatography. RESULTS: Of the nine pandanus cultivars investigated there was a great range of provitamin A carotenoid levels (from 62 to 19,086 microg beta-carotene/100 g), generally with higher levels in those more deeply coloured. Seven pandanus cultivars, one giant swamp taro (Cyrtosperma chamissonis) cultivar and native fig (Ficus tinctoria) had significant provitamin A carotenoid content, meeting all or half of estimated daily vitamin A requirements within normal consumption patterns. Analyses in different laboratories confirmed high carotenoid levels in pandanus but showed that there are still questions as to how high the levels might be, owing to variation arising from different handling/preparation/analytical techniques. CONCLUSIONS: These carotenoid-rich acceptable foods should be promoted for alleviating VAD in Kiribati and possibly other Pacific contexts where these foods are important. Further research in the Pacific is needed to identify additional indigenous foods with potential health benefits.  相似文献   

Determination of the prevalence of antimicrobial resistance genes in canine Clostridium perfringens isolates     

Kather EJ  Marks SL  Foley JE 《Veterinary microbiology》2006,113(1-2):97-101

Clostridium perfringens is a well documented cause of a mild self-limiting diarrhea and a potentially fatal acute hemorrhagic diarrheal syndrome in the dog. A recent study documented that 21% of canine C. perfringens isolates had MIC's indicative of resistance to tetracycline, an antimicrobial commonly recommended for treatment of C. perfringens-associated diarrhea. The objective of the present study was to further evaluate the antimicrobial susceptibility profiles of these isolates by determining the prevalence of specific resistance genes, their expression, and ability for transference between bacteria. One hundred and twenty-four canine C. perfringens isolates from 124 dogs were evaluated. Minimum inhibitory concentrations of tetracycline, erythromycin, tylosin, and metronidazole were determined using the CLSI Reference Agar Dilution Method. All isolates were screened for three tetracycline resistance genes: tetA(P), tetB(P) and tetM, and two macrolide resistance genes: ermB and ermQ, via PCR using primer sequences previously described. Ninety-six percent (119/124) of the isolates were positive for the tetA(P) gene, and 41% (51/124) were positive for both the tetA(P) and tetB(P) genes. No isolates were positive for the tetB(P) gene alone. Highly susceptible isolates (MIC< or = 4 microg/ml) were significantly more likely to lack the tetB(P) gene. One isolate (0.8%) was positive for the ermB gene, and one isolate was positive for the ermQ gene. The tetM gene was not found in any of the isolates tested. Two out of 15 tested isolates (13%) demonstrated transfer of tetracycline resistance via bacterial conjugation. Tetracycline should be avoided for the treatment of C. perfringens-associated diarrhea in dogs because of the relatively high prevalence of in vitro resistance, and the potential for conjugative transfer of antimicrobial resistance.  相似文献   

Evaluation of phenolic compounds in commercial fruit juices and fruit drinks     

Mullen W  Marks SC  Crozier A 《Journal of agricultural and food chemistry》2007,55(8):3148-3157

The total phenolic content of 13 commercially available fruit juices and juice drinks, selected to represent the most popular juice flavors in the United Kingdom, were analyzed using the Folin-Ciocalteu assay. Individual phenolic compounds were identified and quantified using HPLC-PDA-MS2. The catechin content and degree of polymerization of proanthocyanidins were also analyzed. Purple grape juice contained the largest number of individual phenolic compounds and also the highest concentration of total phenolics. The main components were flavan-3-ols, anthocyanins, and hydroxycinnamates, which accounted for 93% of the total phenolic content. In contrast, white grape juice, which contained principally hydroxycinnamates, had the lowest total phenolic content. Antioxidant activity was measured using the ORAC and FRAP assays, and the data obtained were in broad agreement with total phenol content. In view of the recent findings of the Kame project indicating that long-term fruit juice consumption can provide protection against Alzheimer's disease (Dai et al. Am. J. Med. 2006, 379, 464-475), it is suggested that the protective effects may be enhanced by consumption of a combination of juices rich in phenolics and containing a diverse variety of individual phenolic compounds, namely, juices derived from purple grapes, grapefruit, cranberries, and apples.  相似文献   

Quantitative thin layer chromatographic multi-sulfonamide screening procedure: collaborative study     

M H Thomas  R L Epstein  R B Ashworth  H Marks 《Journal of the Association of Official Analytical Chemists》1983,66(4):884-892

A thin layer chromatographic procedure suitable for detection of multiple sulfonamides at 0.1 ppm was studied in an interlaboratory collaborative study. Sulfamethazine, sulfadimethoxine, and sulfaquinoxaline were variously analyzed in liver and muscle tissues from swine, turkey, and duck. The average recovery for all drugs across all tissues was 95%. The corresponding repeatability and reproducibility were 7.7% and 10.5%, respectively.  相似文献   

Tripterygium wilfordii Hook F. versus Sulfasalazine in the treatment of rheumatoid arthritis: a well-designed clinical trial of a botanical demonstrating effectiveness     

Marks WH 《Fitoterapia》2011,82(1):85-87

Claims that Traditional/Alternative medicine (TM/AM) remedies are effective are routinely ignored by Western Medicine. However, the results of a clinical trial that demonstrated the clinical efficacy of Tripterygium wilfordii Hook F. (TW), a TM used as an anti-inflammatory, were recently published in the Annals of Internal Medicine. Why this article was published in a peer reviewed Allopathic medical journal is an important question that begs examination and may lay the future promise of TM/AM therapeutic interventions.  相似文献   

Surgical treatments for intervertebral disc disease.     

J Harari  S L Marks 《Veterinary Clinics of North America: Small Animal Practice》1992,22(4):899-915

Surgical treatments for intervertebral disc disease are useful for animals with gradually progressive, severely acute, or recurrent lesions. Surgical patients require a diligent neuroradiographic evaluation to confirm location and severity of the discopathy and rule out conditions unrelated to disc disease. Although controversial, some surgeons advocate fenestration for recurrent pain or mild ataxia associated with a noncompressive lesion. Decompressive procedures are recommended for treatment and prognostication of compressive disc-associated myelopathy. Foraminotomy is reserved for patients with lateralizing extrusions confirmed with myelography or newer imaging modalities (CT, MRI). Future treatments for animals may include chemonucleolysis or various discectomy procedures currently performed in humans with symptomatic disc disease.  相似文献   

Nicotine activation of alpha4* receptors: sufficient for reward, tolerance, and sensitization     

Tapper AR  McKinney SL  Nashmi R  Schwarz J  Deshpande P  Labarca C  Whiteaker P  Marks MJ  Collins AC  Lester HA 《Science (New York, N.Y.)》2004,306(5698):1029-1032

The identity of nicotinic receptor subtypes sufficient to elicit both the acute and chronic effects of nicotine dependence is unknown. We engineered mutant mice with a4 nicotinic subunits containing a single point mutation, Leu9' --> Ala9' in the pore-forming M2 domain, rendering a4* receptors hypersensitive to nicotine. Selective activation of a4* nicotinic acetylcholine receptors with low doses of agonist recapitulates nicotine effects thought to be important in dependence, including reinforcement in response to acute nicotine administration, as well as tolerance and sensitization elicited by chronic nicotine administration. These data indicate that activation of a4* receptors is sufficient for nicotine-induced reward, tolerance, and sensitization.  相似文献   

Identification of virus-encoded microRNAs   总被引：1，自引：0，他引：1  

Pfeffer S  Zavolan M  Grässer FA  Chien M  Russo JJ  Ju J  John B  Enright AJ  Marks D  Sander C  Tuschl T 《Science (New York, N.Y.)》2004,304(5671):734-736

RNA silencing processes are guided by small RNAs that are derived from double-stranded RNA. To probe for function of RNA silencing during infection of human cells by a DNA virus, we recorded the small RNA profile of cells infected by Epstein-Barr virus (EBV). We show that EBV expresses several microRNA (miRNA) genes. Given that miRNAs function in RNA silencing pathways either by targeting messenger RNAs for degradation or by repressing translation, we identified viral regulators of host and/or viral gene expression.  相似文献