Infection and antibiotic-associated changes in the fecal microbiota of C. rodentium ϕstx2dact-infected C57BL/6 mice

Enterohemorrhagic Escherichia coli causes watery to bloody diarrhea, which may progress to hemorrhagic colitis and hemolytic-uremic syndrome. While early studies suggested that antibiotic treatment may worsen the pathology of an enterohemorrhagic Escherichia coli (EHEC) infection, recent work has shown that certain non-Shiga toxin-inducing antibiotics avert disease progression. Unfortunately, both intestinal bacterial infections and antibiotic treatment are associated with dysbiosis. This can alleviate colonization resistance, facilitate secondary infections, and potentially lead to more severe illness. To address the consequences in the context of an EHEC infection, we used the established mouse infection model organism Citrobacter rodentium ϕstx2dact and monitored changes in fecal microbiota composition during infection and antibiotic treatment. C. rodentium ϕstx2dact infection resulted in minor changes compared to antibiotic treatment. The infection caused clear alterations in the microbial community, leading mainly to a reduction of Muribaculaceae and a transient increase in Enterobacteriaceae distinct from Citrobacter. Antibiotic treatments of the infection resulted in marked and distinct variations in microbiota composition, diversity, and dispersion. Enrofloxacin and trimethoprim/sulfamethoxazole, which did not prevent Shiga toxin-mediated organ damage, had the least disruptive effects on the intestinal microbiota, while kanamycin and tetracycline, which rapidly cleared the infection without causing organ damage, caused a severe reduction in diversity. Kanamycin treatment resulted in the depletion of all but Bacteroidetes genera, whereas tetracycline effects on Clostridia were less severe. Together, these data highlight the need to address the impact of individual antibiotics in the clinical care of life-threatening infections and consider microbiota-regenerating therapies.IMPORTANCEUnderstanding the impact of antibiotic treatment on EHEC infections is crucial for appropriate clinical care. While discouraged by early studies, recent findings suggest certain antibiotics can impede disease progression. Here, we investigated the impact of individual antibiotics on the fecal microbiota in the context of an established EHEC mouse model using C. rodentium ϕstx2dact. The infection caused significant variations in the microbiota, leading to a transient increase in Enterobacteriaceae distinct from Citrobacter. However, these effects were minor compared to those observed for antibiotic treatments. Indeed, antibiotics that most efficiently cleared the infection also had the most detrimental effect on the fecal microbiota, causing a substantial reduction in microbial diversity. Conversely, antibiotics showing adverse effects or incomplete bacterial clearance had a reduced impact on microbiota composition and diversity. Taken together, our findings emphasize the delicate balance required to weigh the harmful effects of infection and antibiosis in treatment.

Effects of squamous cell carcinoma and smoking status on oropharyngeal and laryngeal microbial communities

BACKGROUND

Still, little is known about microbial dysbiosis in oropharyngeal and laryngeal tissue as risk factor for development of local squamous cell carcinoma. The site-specific microbiota at these regions in healthy and cancer tissue and their modulation by environmental factors need to be defined.

METHODS

The local microbiota of cancer tissue and healthy controls was profiled by 16S rRNA gene amplicon sequencing and statistical analysis using 111 oropharyngeal and 72 laryngeal intraoperative swabs.

RESULTS

Oropharynx and larynx harbor distinct microbial communities. Clear effects of both smoking and cancer were seen in the oropharynx whereas effects in the larynx were minor.

CONCLUSION

The distinct microbial communities at larynx and oropharynx partially explain why the effects of cancer and smoking were distinct at those sites. Thus, the use of microbiota supposed to mirror community changes in another target location should be avoided and more studies on the actual cancerous environment are necessary.

Gender-specific changes of the gut microbiome correlate with tumor development in murine models of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a dismal outcome. To improve understanding of sequential microbiome changes during PDAC development we analyzed mouse models of pancreatic carcinogenesis (KC mice recapitulating pre-invasive PanIN formation, as well as KPC mice recapitulating invasive PDAC) during early tumor development and subsequent tumor progression. Diversity and community composition were analyzed depending on genotype, age, and gender. Both mouse models demonstrated concordant abundance changes of several genera influenced by one or more of the investigated factors. Abundance was significantly impacted by gender, highlighting the need to further elucidate the impact of gender differences. The findings underline the importance of the microbiome in PDAC development and indicate that microbiological screening of patients at risk and targeting the microbiome in PDAC development may be feasible in future.

The biliary microbiome in ischaemic-type biliary lesions can be shaped by stenting but is resilient to antibiotic treatment

This study aims to characterize the biliary microbiome as neglected factor in patients with ischaemic-type biliary lesions (ITBL) after liver transplantation. Therefore, the V1-V2 region of the 16S rRNA gene was sequenced in 175 bile samples. Samples from patients with anastomotic strictures (AS) served as controls. Multivariate analysis and in silico metagenomics were applied cross-sectionally and longitudinally. The microbial community differed significantly between ITBL and AS in terms of alpha and beta diversity. Both, antibiotic treatment and stenting were associated independently with differences in the microbial community structure. In contrast to AS, in ITBL stenting was associated with pronounced differences in the biliary microbiome, whereas no differences associated with antibiotic treatment could be observed in ITBL contrasting the pronounced differences found in AS. Bacterial pathways involved in the production of antibacterial metabolites were increased in ITBL with antibiotic treatment. After liver transplantation, the biliary tract harbours a complex microbial community with significant differences between ITBL and AS. Fundamental changes in the microbial community in ITBL can be achieved with biliary stenting. However, the effect of antibiotic treatment in ITBL was minimal. Therefore, antibiotics should be administered wisely in order to reduce emerging resistance of the biliary microbiome towards external antibiotics.

Eradication of Chronic HCV Infection: Improvement of Dysbiosis Only in Patients Without Liver Cirrhosis

BACKGROUND AND AIMS

It is well accepted that liver diseases and their outcomes are associated with intestinal microbiota, but causality is difficult to establish. The intestinal microbiota are altered in patients with hepatitis C. As chronic HCV infection can now be cured in almost all patients, it is an ideal model to study the influence of liver disease on the microbiota.

APPROACH AND RESULTS

We aimed to prospectively analyze the changes in the gut microbiome in patients who received direct-acting antivirals (DAA) and achieved sustained virological response (SVR). Amplicon sequencing of the V1-V2 region in the 16S ribosomal RNA gene was performed in stool samples of patients with chronic hepatitis C. Patients in the treatment group received DAA (n = 65), whereas in the control group, no DAA were given (n = 33). Only patients achieving SVR were included. The alpha diversity increased numerically but not significantly from baseline to SVR at week 24 or 48 (SVR24/48; 2.784 ± 0.248 vs. 2.846 ± 0.224; P = 0.057). When stratifying for the presence of liver cirrhosis, a significant increase in diversity was only seen in patients without cirrhosis. Differences in the microbial community structure induced by the achievement of SVR were only observed in patients without liver cirrhosis. In patients with liver cirrhosis and in the control group, no significant differences were observed.

CONCLUSIONS

In conclusion, the achievement of SVR24/48 in patients with chronic HCV was associated with changes in the intestinal microbiota. However, these changes were only seen in patients without liver cirrhosis. A major role of liver remodeling on the intestinal microbiota is indicated by the dynamics of the intestinal microbial community structure depending on the stage of fibrosis in patients resolving chronic hepatitis C.

Effects of mixed tocopherols added to milk replacer and calf starter on intake, growth, and indices of stress

Vitamin E comprises 8 fat-soluble isoforms: α-, β-, γ-, and δ-tocopherol and α-, β-, γ-, and δ-tocotrienol. Yet the body preferentially uses α-tocopherol, and only α-tocopherol supplementation can reverse vitamin E deficiency symptoms. However, other isoforms influence many biological functions in the body, including inflammation and stress. Therefore, the study objective was to determine metabolic and performance responses in young calves fed diets containing a constant amount of α-tocopherol and increasing amounts of soybean oil-derived mixed γ- and δ-tocopherols. Holstein calves [n = 48; 2-3 d of age; 40.2 kg of initial body weight (BW), standard error = 0.54] were assigned to receive approximately 0, 5, 10, or 15 mg/kg of BW daily (treatments T0, T1, T2, and T3, respectively) of mixed tocopherols (TMIX) provided in milk replacer (MR) and calf starter. The TMIX liquid contained 86% γδ-tocopherols and 9% α-tocopherol. Milk replacers were formulated to contain approximately 0, 400, 800, or 1,200 mg of TMIX/kg for treatments T0, T1, T2, and T3, respectively. Calf starters were formulated to contain approximately 0, 250, 500, or 750 mg of TMIX/kg for treatments T0, T1, T2, and T3, respectively. Mean consumption of γδ-tocopherols was 0.0, 6.5, 14.3, and 20.5 mg/kg of BW, respectively. Milk replacer contained 24% crude protein (CP) and 20% fat on a dry matter (DM) basis. Calf starters were pelleted and offered for ad libitum consumption from 0 to 56 d. Starters contained 18 to 20% CP and 9 to 12% starch in the DM. On d 28, 4 calves per treatment were randomly selected for slaughter, and necropsy was performed. Samples of liver, duodenum, ileum, and trapezius muscle were collected and stored before analysis for α-, β-, γ-, and δ-tocopherols and δ-tocotrienol. Data were analyzed using a completely randomized design using mixed model ANOVA with orthogonal polynomials to determine linear and quadratic effects of TMIX. Repeated-measures analyses were performed for data collected over time. Increasing dietary TMIX increased or tended to increase change in hip width at 28 and 56 d, respectively, and improved average daily BW gain and gain-to-feed ratio at 56 d. Increasing TMIX reduced plasma xanthine oxidase at 0 h and tended to reduce concentrations at 24 h following vaccination with 2 commercial vaccines on d 28; however, we detected no effect of TMIX following vaccination on d 56. Concentration of α-tocopherol in skeletal muscle declined quadratically with increasing TMIX, whereas ileal and liver γ-tocopherol increased linearly with increasing TMIX. The number of mucin-2 cells in the ileum increased more than 2-fold in calves fed T3. Addition of mixed tocopherols to diets of young dairy calves improved animal growth and altered indices of antioxidant metabolism.

The effect of delayed feeding post-hatch on caeca development in broiler chickens

1. Broiler chicks are frequently deprived of food up to 72 h due to uneven hatching rates, management procedures and transportation to farms. Little is known about the effect of delayed feeding due to extended hatching times on the early neonatal development of the caeca. Therefore, the objective of this study was to investigate the developmental changes and effects of a 48-h delay in feed access immediately post-hatch (PH) on the caeca.2. After hatch, birds (Ross 708) were randomly divided into two treatment groups (n = 6 battery pen/treatment). One group (early fed; EF) received feed and water immediately after hatch, while the second group (late fed; LF) had access to water but had delayed access to feed for 48 h. Contents averaging across all regions of the caeca were collected for mRNA expression as well as for histological analysis at -48, 0, 4 h PH and then at 1, 2, 3, 4, 6, 8, 10, 12 and 14 days PH.3. Expression of MCT-1 (a nutrient transporter), Cox7A2 (related to mitochondrial function) IgA, pIgR, and ChIL-8 (immune function) genes was affected by delayed access to feed that was dependent by the time PH. Expression of immune and gut barrier function-related genes (LEAP2 and MUC2, respectively) was increased in LF group. There was no effect of feed delay on expression of genes related to mitochondrial functions in the caeca, although developmental changes were observed (ATP5F1B, Cox4|1). Caecal mucus and muscle thickness were affected by delayed access to feed during caeca development.4. The data suggested a limited effect of delayed feed access PH on the developmental changes in caecal functions. However, the caeca seemed to be relatively resistant to delayed access to feed early PH, with only a few genes affected.

Peripheral histamine and neonatal growth performance in swine

Identification of plasma and/or serum markers at birth that will predict animal performance may be useful for identifying animals susceptible to poor growth. Metabolomic analysis of plasma from newborn swine was used to identified potential metabolite differences between 8 pairs of littermates with similar birth weights but whose ADG differed by >50 g/d so that, at weaning (21 d), littermates differed in BW by 1.62 kg (P < 0.01). Plasma analysis failed to identify metabolic pathways impacted by growth, most likely because of the small sample population. Interestingly, despite comparative analysis of 576 metabolites between these slow-growing and normal-growing littermates, the relative abundance of only 36 metabolites differed between the pairs. Most of these metabolites could be eliminated as potential markers because of the difficulty with the extraction and rapid measurement of their plasma/serum concentrations. Histamine differed from most of these potential metabolite markers in that commercial sandwich ELISAs are readily available. Using an ELISA, we verified the metabolomic data, demonstrating that plasma histamine concentrations were 150% higher in slow-growing than normal growing littermates of similar birth weight (P < 0.05). Subsequently, a separate data set was obtained using swine from a different geographical location and genetic background and also showed that elevated histamine (ng/mL) at birth is associated with increased preweaning growth rate (P = 0.009, r = 0.306, n = 9 litters). Together, the data indicate that perinatal histamine concentrations may serve as a tool to identify potentially slower growing pigs and as a serum biomarker for predicting litter growth rate.

Effect of Holstein genotype on innate immune and metabolic responses of heifers to lipopolysaccharide (LPS) administration

Heifers (n = 4/genotype) from unselected (stable genotype since 1964, UH) and contemporary (CH) Holsteins that differed in milk yield (6,200 and 11,100 kg milk/305 d) were used to assess the impact of selection on innate immune and acute-phase response to an endotoxin (lipopolysaccharide; LPS). Jugular catheters were implanted 24 h before LPS administration. Blood samples were collected at -1, -0.5, 0, 1, 2, 3, 4, 6, 8, and 24 h relative to iv administration of 0.5 μg LPS/kg BW. Rectal body temperature (BT) was determined at these sampling times and at 5 and 7 h. Dermal biopsies were collected after the 24 h blood sample and processed to isolate fibroblasts. Plasma was analyzed for tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), serum amyloid A (SAA), xanthine oxidase (XO), and nitrate + nitrite (NOx), cortisol, glucose, and IGF-1 content. Isolated fibroblasts were exposed to IL-1β or LPS and IL-6 and IL-8 content of culture media determined. Exposure to LPS increased BTs and plasma concentrations of TNF-α, IL-6 SAA, XO, cortisol, and glucose (P < 0.05) in both genotypes. Plasma concentrations of TNF-α, XO, NOx, and glucose did not differ (P > 0.25) between the genotypes, but IL-6 and SAA concentrations were reduced (P < 0.05) in CH relative to UH heifers while cortisol and IGF-1 concentrations tended (P < 0.08) to be reduced in CH heifers. After 36 h exposure to LPS, concentrations of IL-6 were greater (P < 0.05) in culture media from incubations of CH than UH fibroblasts but concentrations of IL-8 did not differ between genotypes. There was a trend (P = 0.08) for IL-8 concentrations to be reduced in media from CH fibroblasts exposed to IL-1β for 24 h but IL-6 concentrations did not differ between genotypes. Results indicate 50 yr of selection has reduced the robustness of the innate immune and acute-phase response to LPS in the contemporary Holstein heifer.

Phlebologische Funktionsdiagnostik: Praktische Anwendung

Trotz der Dominanz der farbkodierten Duplexsonographie in der Diagnostik der Phlebologie gibt es weiterhin Fragestellungen, bei denen klassische Verfahren der phlebologischen Funktionsdiagnostik eine wichtige Rolle bei der Therapieentscheidung spielen.

Während die farbkodierte Duplexsonographie detallierten Aufschluss über die Kaliber und die Refluxsituation des Venensysthems liefern kann, ist sie jedoch nicht in der Lage, eine abschließende Aussage zur Hämodynamik zu treffen. Hierzu dient die venöse Funktionsdiagnostik und als Referenzverfahren insbesondere die invasive Phlebodynamometrie (PDM).

Das Ziel dieses dreiteiligen Artikels besteht darin, die praktische Anwendung der klassischen Verfahren zur phlebologischen Funktionsdiagnostik im klinischen Rahmen zu demonstrieren und die Aussagekraft der entsprechend erhobenen Daten zu erläutern. In diesem dritten Teil wird entsprechend die Venenverschlussplethysmographie (VVP) beschrieben. Sie spielt aufgrund der Möglichkeit der Bestimmung von venöser Kapazität, venösem Ausstrom und arteriellem Einstrom eine Rolle in der Diagnostik der Varikosis, der tiefen Beinvenenthrombose und der peripheren arteriellen Verschlusskrankheit. Direkte Aussagen zur Hämodynamik können mit Hilfe dieser Methode jedoch nicht getroffen werden.

In vorherigen Ausgaben der „Phlebologie“ wurden bereits die digitale Photoplethysmographie (D-PPG) und die PDM vorgestellt.

Die praktische Anwendung der D-PPG, der PDM und der VVP ist prinzipiell nicht schwer. Für die Durchführung wird jedoch geschultes Personal benötigt, um Anwendungs- und Messfehler zu vermeiden.

The impact of proton pump inhibitors on the intestinal microbiota in chronic hepatitis C patients

Objectives: Proton pump inhibitors (PPI), a class of drugs commonly used, are known to be associated with changes in the intestinal microbiota. Published studies were done in heterogeneous cohorts which could hamper conclusions drawn as effects of diseases were not taken into consideration. We aimed to elucidate differences in the intestinal microbiota being associated to the use of PPI in a cohort study of patients with chronic hepatitis C. Material and Methods: The 16S rDNA gene was analyzed in stool samples of patients with and without PPI use. Patients with concomitant medication influencing the microbiota were excluded. Results were compared with the clinical course of hepatitis C patients with decompensated liver cirrhosis. Results: No differences in alpha diversity could be observed, while the microbial community structure differed significantly, especially in patients with liver cirrhosis. The relative abundance of Streptococcus spp., Enterobacter spp. and Haemophilus spp. was significantly increased in patients with PPI use irrespectively of the stage of liver disease. Finally, in patients with decompensated liver cirrhosis due to chronic HCV infection only in these using PPI bacterial phylotypes were isolated. Conclusions: PPI use was associated with significant alterations in the microbial community in patients with chronic hepatitis C, which were even pronounced in patients with liver cirrhosis. In patients with decompensated liver cirrhosis due to chronic HCV infection, the use of PPI may promote infections either directly or indirectly through changes in the microbial community structure. Future studies should further investigate long-term impact on the microbiota and the clinical outcome.

Phlebologische Funktionsdiagnostik: Praktische Anwendung

Trotz der Dominanz der farbkodierten Duplexsonografie in der Diagnostik der Phlebologie gibt es weiterhin Fragestellungen, bei denen klassische Verfahren der phlebologischen Funktionsdiagnostik eine wichtige Rolle bei der Therapieentscheidung spielen.

Während die farbkodierte Duplexsonografie detallierten Aufschluss über die Kaliber und die Refluxsituation des Venensystems liefern kann, ist sie jedoch nicht in der Lage, eine abschließende Aussage zur Hämodynamik zu treffen. Hierzu dient die venöse Funktionsdiagnostik und als Referenzverfahren insbesondere die invasive Phlebodynamometrie (PDM). Die PDM ist die einzige Methode zur direkten Messung der ambulatorischen venösen Hypertonie und hat daher eine große Bedeutung im Rahmen der funktionellen phlebologischen Diagnostik, insbesondere beim postthrombotischen Syndrom (PTS). Sie kann am verlässlichsten darüber Auskunft geben, ob es sich bei Vorliegen einer Varikosis mit kurzem Reflux im Rahmen eines PTS um eine besserbare Varikosis handelt oder nicht.

Das Ziel dieses dreiteiligen Artikels besteht darin, die praktische Anwendung der klassischen Verfahren zur phlebologischen Funktionsdiagnostik im klinischen Rahmen zu demonstrieren und die Aussagekraft der entsprechend erhobenen Daten zu erläutern. Die praktische Anwendung der digitalen Photoplethysmografie (D-PPG), der PDM und der Venenverschlussplethysmografie (VVP) ist prinzipiell nicht schwer. Für die Durchführung wird jedoch geschultes Personal benötigt, um Anwendungs- und Messfehler zu vermeiden. In diesem zweiten Teil soll die Phlebodynamometrie vorgestellt und erläutert werden.

Phlebologische Funktionsdiagnostik: Praktische Anwendung

Trotz der Dominanz der farbkodierten Duplexsonografie in der Diagnostik der Phlebologie gibt es weiterhin Fragestellungen, bei denen klassische Verfahren der phlebologischen Funktionsdiagnostik eine wichtige Rolle bei der Therapieentscheidung spielen.

Während die farbkodierte Duplexsonografie detaillierten Aufschluss über die Kaliber und die Refluxsituation des Venensystems liefern kann, ist sie jedoch nicht in der Lage, eine abschließende Aussage zur Hämodynamik zu treffen. Hierzu dient die venöse Funktionsdiagnostik und als Referenzverfahren insbesondere die invasive Phlebodynamometrie (PDM). Die PDM ist die einzige Methode zur direkten Messung der ambulatorischen venösen Hypertonie und hat daher eine große Bedeu-tung im Rahmen der funktionellen phlebologischen Diagnostik, insbesondere beim postthrombostischen Syndrom (PTS). Sie kann am verlässlichsten darüber Auskunft geben, ob es sich bei Vorliegen einer Varikosis mit kurzem Reflux im Rahmen eines PTS um eine besserbare Varikosis handelt oder nicht.

Das Ziel dieses dreiteiligen Artikels besteht darin, die praktische Anwendung der klassischen Verfahren zur phlebologischen Funktionsdiagnostik im klinischen Rahmen zu demonstrieren und die Aussagekraft der entsprechend erhobenen Daten zu erläutern. Die praktische Anwendung der digitalen Photoplethysmografie (D-PPG), der PDM und der Venenverschlussplethysmografie (VVP) ist prinzipiell nicht schwer. Für die Durchführung wird jedoch geschultes Personal benötigt, um Anwendungs- und Messfehler zu vermeiden. In diesem ersten Teil soll die digitale Photoplethysmografie vorgestellt und erläutert werden.

Determining lineage-specific bacterial growth curves with a novel approach based on amplicon reads normalization using internal standard (ARNIS)

The growth rate is a fundamental characteristic of bacterial species, determining its contributions to the microbial community and carbon flow. High-throughput sequencing can reveal bacterial diversity, but its quantitative inaccuracy precludes estimation of abundances and growth rates from the read numbers. Here, we overcame this limitation by normalizing Illumina-derived amplicon reads using an internal standard: a constant amount of Escherichia coli cells added to samples just before biomass collection. This approach made it possible to reconstruct growth curves for 319 individual OTUs during the grazer-removal experiment conducted in a freshwater reservoir Římov. The high resolution data signalize significant functional heterogeneity inside the commonly investigated bacterial groups. For instance, many Actinobacterial phylotypes, a group considered to harbor slow-growing defense specialists, grew rapidly upon grazers' removal, demonstrating their considerable importance in carbon flow through food webs, while most Verrucomicrobial phylotypes were particle associated. Such differences indicate distinct life strategies and roles in food webs of specific bacterial phylotypes and groups. The impact of grazers on the specific growth rate distributions supports the hypothesis that bacterivory reduces competition and allows existence of diverse bacterial communities. It suggests that the community changes were driven mainly by abundant, fast, or moderately growing, and not by rare fast growing, phylotypes. We believe amplicon read normalization using internal standard (ARNIS) can shed new light on in situ growth dynamics of both abundant and rare bacteria.

High diversity of thermophilic cyanobacteria in Rupite hot spring identified by microscopy, cultivation, single-cell PCR and amplicon sequencing

Genotypic and morphological diversity of cyanobacteria in the Rupite hot spring (Bulgaria) was investigated by means of optical microscopy, cultivation, single-cell PCR, and 16S rRNA gene amplicon sequencing. Altogether, 34 sites were investigated along the 71-39 °C temperature gradient. Analysis of samples from eight representative sites shown that Illumina, optical microscopy, and Roche 454 identified 72, 45 and 19% respective occurrences of all cumulatively present taxa. Optical microscopy failed to detect species of minor occurrence; whereas, amplicon sequencing technologies suffered from failed primer annealing and the presence of species with extensive extracellular polysaccharides production. Amplicon sequencing of the 16S rRNA gene V5-V6 region performed by Illumina identified the cyanobacteria most reliably to the generic level. Nevertheless, only the combined use of optical microscopy, cultivation and sequencing methods allowed for reliable estimate of the cyanobacterial diversity. Here, we show that Rupite hot-spring system hosts one of the richest cyanobacterial flora reported from a single site above 50 °C. Chlorogloeopsis sp. was the most abundant at the highest temperature (68 °C), followed by Leptolyngbya boryana, Thermoleptolyngbya albertanoae, Synechococcus bigranulatus, Oculatella sp., and Desertifilum sp. thriving above 60 °C, while Leptolyngbya geysericola, Geitlerinema splendidum, and Cyanobacterium aponinum were found above 50 °C.

Intestinal microbiota in patients with chronic hepatitis C with and without cirrhosis compared with healthy controls

BACKGROUND & AIMS

The importance of the intestinal microbiota for the onset and clinical course of many diseases, including liver diseases like non-alcoholic steatohepatitis and cirrhosis, is increasingly recognized. However, the role of intestinal microbiota in chronic hepatitis C virus (HCV) infection remains unclear.

METHODS

In a cross-sectional approach, the intestinal microbiota of 95 patients chronically infected with HCV (n=57 without cirrhosis [NO-CIR]; n=38 with cirrhosis [CIR]) and 50 healthy controls (HC) without documented liver diseases was analysed.

RESULTS

Alpha diversity, measured by number of phylotypes (S) and Shannon diversity index (H'), decreased significantly from HC to NO-CIR to CIR. S and H' correlated negatively with liver elastography. Analysis of similarities revealed highly statistically significant differences in the microbial communities between HC, NO-CIR and CIR (R=.090; P<1.0×10^-6 ). Stratifying for HCV genotypes even increased the differences. In addition, we observed distinct patterns in the relative abundance of genera being either positive or negative correlated with diseases status.

CONCLUSIONS

This study shows that not only the stage of liver disease but also HCV infection is associated with a reduced alpha diversity and different microbial community patterns. These differences might be caused by direct interactions between HCV and the microbiota or indirect interactions facilitated by the immune system.

Exploring the bacterial assemblages along the human nasal passage

The human nasal passage, from the anterior nares through the nasal vestibule to the nasal cavities, is an important habitat for opportunistic pathogens and commensals alike. This work sampled four different anatomical regions within the human nasal passage across a large cohort of individuals (n = 79) comprising individuals suffering from chronic nasal inflammation clinically known as chronic rhinosinusitis (CRS) and individuals not suffering from inflammation (CRS-free). While individuals had their own unique bacterial fingerprint that was consistent across the anatomical regions, these bacterial fingerprints formed into distinct delineated groups comprising core bacterial members, which were consistent across all four swabbed anatomical regions irrespective of health status. The most significant observed pattern was the difference between the global bacterial profiles of swabbed and tissue biopsy samples from the same individuals, being also consistent across different anatomical regions. Importantly, no statistically significant differences could be observed concerning the global bacterial communities, any of the bacterial species or the range of diversity indices used to compare between CRS and CRS-free individuals, and between two CRS phenotypes (without nasal polyps and with nasal polyps). Thus, the role of bacteria in the pathogenesis of sinusitis remains uncertain.

A sandwich ELISA for porcine alpha-1 acid glycoprotein (pAGP, ORM-1) and further demonstration of its use to evaluate growth potential in newborn pigs

A simple, reproducible sandwich, ELISA was developed to measure porcine alpha-1 acid glycoprotein (pAGP, ORM-1) in pig plasma. Porcine AGP isolated from serum was purchased and a polyclonal antisera was prepared in rabbits using the whole pAGP molecule as immunogen. The antiserum was affinity purified, and a portion of the purified antibody fraction was labeled with horseradish peroxidase. Porcine AGP protein was used as a standard, whereas commercially available buffers and reagents were utilized throughout the assay. The assay was specific for pAGP, had a lower limit of detection of 3.2 ng/mL, and could be used to quantify pAGP in plasma or serum. Using this ELISA, we corroborated our previous findings obtained by RID assay, which demonstrated that the AGP concentration in newborn piglets is negatively associated with preweaning growth rate. The current data were obtained using piglets from a different geographical location and genetic background and showed that elevated AGP at birth was associated with reduced preweaning growth rate (P < 0.001, r = 0.433, n = 19 litters). In addition, litters with a greater average AGP at birth were at a growth disadvantage compared with litters with reduced average AGP plasma concentrations (P < 0.001, r = 0.708, n = 19 litters). Litter average plasma AGP was a better predictor of litter preweaning growth rate than average litter birth weight. The data represent further support for using perinatal AGP concentrations as a tool to identify potential slower growing pigs and as a plasma biomarker for predicting litter growth rate.

In utero heat stress increases postnatal core body temperature in pigs

In utero heat stress (IUHS) negatively impacts postnatal development, but how it alters future body temperature parameters and energetic metabolism is not well understood. Future body temperature indices and bioenergetic markers were characterized in pigs from differing in utero thermal environments during postnatal thermoneutral (TN) and cyclical heat stress (HS) exposure. First-parity pregnant gilts ( = 13) were exposed to 1 of 4 ambient temperature (T) treatments (HS [cyclic 28°C to 34°C] or TN [cyclic 18°C to 22°C]) applied for the entire gestation (HSHS, TNTN), HS for the first half of gestation (HSTN), or HS for the second half of gestation (TNHS). Twenty-four offspring (23.1 ± 1.2 kg BW; = 6 HSHS, = 6 TNTN, = 6 HSTN, = 6 TNHS) were housed in TN (21.7°C ± 0.7°C) conditions and then exposed to 2 separate but similar HS periods (HS1 = 6 d; HS2 = 6 d; cycling 28°C to 36°C). Core body temperature (T) was assessed every 15 min with implanted temperature recorders. Regardless of in utero treatment, T increased during both HS periods ( = 0.01; 0.58°C). During TN, HS1, and HS2, all IUHS pigs combined had increased T ( = 0.01; 0.36°C, 0.20°C, and 0.16°C, respectively) compared to TNTN controls. Although unaffected by in utero environment, the total plasma thyroxine to triiodothyronine ratio was reduced ( = 0.01) during HS1 and HS2 (39% and 29%, respectively) compared with TN. In summary, pigs from IUHS maintained an increased T compared with TNTN controls regardless of external T, and this thermal differential may have practical implications to developmental biology and animal bioenergetics.

COMPARATIVE GUT PHYSIOLOGY SYMPOSIUM: Comparative physiology of glucagon-like peptide-2: Implications and applications for production and health of ruminants

Glucagon-like peptide-2 (GLP-2) is a 33-amino acid peptide derived from proteolytic cleavage of proglucagon by prohormone convertase 1/3 in enteroendocrine L cells. Studies conducted in humans, in rodent models, and in vitro indicate that GLP-2 is secreted in response to the presence of molecules in the intestinal lumen, including fatty acids, carbohydrates, amino acids, and bile acids, which are detected by luminal chemosensors. The physiological actions of GLP-2 are mediated by its G protein-coupled receptor expressed primarily in the intestinal tract on enteric neurons, enteroendocrine cells, and myofibroblasts. The biological activity of GLP-2 is further regulated by dipeptidyl peptidase IV, which rapidly cleaves the N-terminus of GLP-2 that is responsible for GLP-2 receptor activation. Within the gut, GLP-2 increases nutrient absorption, crypt cell proliferation, and mesenteric blood flow and decreases gut permeability and motility, epithelial cell apoptosis, and inflammation. Outside the gut, GLP-2 reduces bone resorption, can suppress appetite, and is cytoprotective in the lung. Thus, GLP-2 has been studied intensively as a therapeutic to improve intestinal function of humans during parenteral nutrition and following small bowel resection and, more recently, as a treatment for osteoporosis and obesity-related disorders and to reduce cellular damage associated with inflammation of the gut and lungs. Recent studies demonstrate that many biological actions and properties of GLP-2 in ruminants are similar to those in nonruminants, including the potential to reduce intestinal nitro-oxidative stress in calves caused by parasitic diseases such as coccidiosis. Because of its beneficial impacts on nutrient absorption, gut healing, and normal gut development, GLP-2 therapy offers significant opportunities to improve calf health and production efficiency. However, GLP-2 therapies require an extended time course to achieve desired physiological responses, as well as daily administration because of the hormone's short half-life. Thus, practical means of administration and alternative strategies to enhance basal GLP-2 secretion (e.g., through specific feed additives), which are more likely to achieve consumer acceptance, are needed. Opportunities to address these challenges are discussed.

English language version of the S3-consensus guidelines on chronic pancreatitis: Definition, aetiology, diagnostic examinations, medical, endoscopic and surgical management of chronic pancreatitis

Chronic pancreatitis is a disease of the pancreas in which recurrent inflammatory episodes result in replacement of pancreatic parenchyma by fibrous connective tissue. This fibrotic reorganization of the pancreas leads to a progressive exocrine and endocrine pancreatic insufficiency. In addition, characteristic complications arise, such as pseudocysts, pancreatic duct obstructions, duodenal obstruction, vascular complications, obstruction of the bile ducts, malnutrition and pain syndrome. Pain presents as the main symptom of patients with chronic pancreatitis. Chronic pancreatitis is a risk factor for pancreatic carcinoma. Chronic pancreatitis significantly reduces the quality of life and the life expectancy of affected patients. These guidelines were researched and compiled by 74 representatives from 11 learned societies and their intention is to serve evidence-based professional training as well as continuing education. On this basis they shall improve the medical care of affected patients in both the inpatient and outpatient sector. Chronic pancreatitis requires an adequate diagnostic workup and systematic management, given its severity, frequency, chronicity, and negative impact on the quality of life and life expectancy.

The microbial community structure of the cotton rat nose

The cotton rat nose is commonly used as a model for Staphylococcus aureus colonization, as it is both physiologically and anatomically comparable to the human nares and can be easily colonized by this organism. However, while the colonization of the human anterior nares has been extensively studied, the microbial community structure of cotton rat noses has not been reported so far. We describe here the microbial community structure of the cotton rat (Sigmodon hispidus) nose through next-generation sequencing of 16S rRNA gene amplicons covering the V1-V2 region and the analysis of nearly full length 16S rRNA genes of the major phylotypes. Roughly half of the microbial community was composed of two undescribed species of the genus Campylobacter, with phylotypes belonging to the genera Catonella, Acholeplasma, Streptobacillus and Capnocytophaga constituting the predominant community members. Thus, the nasal community of the cotton rat is uniquely composed of several novel bacterial species and may not reflect the complex interactions that occur in human anterior nares. Mammalian airway microbiota may, however, be a rich source of hitherto unknown microbes.

Environmental heat stress modulates thyroid status and its response to repeated endotoxin challenge in steers

The objective of this study was to evaluate in cattle, the effects of acute exposure to a heat stress (HS) environment on the status of the pituitary (thyrotropin, TSH)-thyroid (thyroxine, T4)-peripheral tissue T4 deiodination (type 1 5'-deiodinase [D1]; triiodothyronine [T3]; reverse-triiodothyronine [rT3]) axis, and the further response of this pituitary-thyroid-peripheral tissue axis (PTTA) to perturbation caused by the induction of the proinflammatory innate immune state provoked by the administration of gram-negative bacteria endotoxin (lipopolysaccharide [LPS]). Ten steers (318 ± 49 kg body weight) housed in controlled environment chambers were subjected to either a thermoneutral (TN: constant 19°C) or HS temperature conditions (cyclical daily temperatures: 32.2°C-40.0°C) for a total period of 9 d. To minimize the effects of altered plane of nutrition due to HS, steers in TN were pair-fed to animals in HS conditions. Steers received 2 LPS challenges 3 d apart (LPS1 and LPS2; 0.2 μg/kg body weight, intravenously, Escherichia coli 055:B5) with the first challenge administered on day 4 relative to the start of the environmental conditioning. Jugular blood samples were collected at 0, 1, 2, 4, 7, and 24 h relative to the start of each LPS challenge. Plasma TSH, T4, T3, and rT3 were measured by radioimmunoassay. Liver D1 activity was measured in biopsy samples collected before the LPS1 (0 h) and 24 h after LPS2. Before the start of LPS1, HS decreased (P < 0.01 vs TN) plasma TSH (40%), T4 (45.4%), and T3 (25.9%), but did not affect rT3 concentrations. In TN steers, the LPS1 challenge decreased (P < 0.01 vs 0 h) plasma concentrations of TSH between 1 and 7 h and T4 and T3 at 7 and 24 h. In HS steers, plasma TSH concentrations were decreased at 2 h only (P < 0.05), whereas plasma T3 was decreased at 7 and 24 h (P < 0.01). Whereas plasma T4 concentrations were already depressed in HS steers at 0 h, LPS1 did not further affect the levels. Plasma rT3 concentrations were increased in all steers at 4, 7, and 24 h after LPS1 (P < 0.01). The patterns of concentration change of T4, T3, and rT3 during LPS2 mirrored those observed in LPS1; the responses in plasma TSH were of smaller magnitude than those incurred after LPS1. The LPS challenges reduced (P < 0.01) hepatic activity of D1 in all animals but no differences were observed between steers subjected to TN or HS environment. The data are consistent with the concept that acute exposure of cattle to a HS environment results in the depression of the pituitary and thyroid components of the PTTA, whereas a normal capacity to generate T3 from T4 in the liver is preserved. The data also suggest that LPS challenge further suppresses all components of the PTTA including liver T3 generation, and these PTTA perturbations are more pronounced in steers that encounter a HS exposure.

Transcriptional regulators transforming growth factor-β1 and estrogen-related receptor-α identified as putative mediators of calf rumen epithelial tissue development and function during weaning

Molecular mechanisms regulating rumen epithelial development remain largely unknown. To identify gene networks and regulatory factors controlling rumen development, Holstein bull calves (n=18) were fed milk replacer only (MRO) until 42 d of age. Three calves each were euthanized at 14 and 42 d of age for tissue collection to represent preweaning, and the remaining calves were provided diets of either milk replacer + orchard grass hay (MH; n=6) to initiate weaning without development of rumen papillae, or milk replacer + calf starter (MG; n=6) to initiate weaning and development of rumen papillae. At 56 and 70 d of age, 3 calves from the MH and MG groups were euthanized for collection of rumen epithelium. Total RNA and protein were extracted for microarray analysis and to validate detected changes in selected protein expression, respectively. As expected, calves fed MRO had no rumen papillae and development of papillae was greater in MG versus MH calves. Differentially expressed genes between the MRO diet at d 42 (preweaning) versus the MG or MH diets at d 56 (during weaning) were identified using permutation analysis of differential expression. Expression of 345 and 519 transcripts was uniquely responsive to MG and MH feeding, respectively. Ingenuity Pathway Analysis (Qiagen, Redwood City, CA) indicated that the top-ranked biological function affected by the MG diet was the cell cycle, and TFGB1, FBOX01, and PPARA were identified as key transcriptional regulators of genes responsive to the MG diet and associated with development of rumen papillae. Increased expressions of TGFB1 mRNA and protein in response to the MG diet were confirmed by subsequent analyses. The top-ranking biological function affected by the MH diet was energy production. Receptors for IGF-1 and insulin, ESRRA, and PPARD were identified by ingenuity pathway analysis as transcriptional regulators of genes responsive to the MH diet. Further analysis of TGFB1 and ESRRA mRNA expression in rumen epithelium obtained from a separate ontogenic study of Holstein calves (n=26) euthanized every 7d from birth to 42 d of age showed increases in transcript expression with advancing age, supporting their roles in mediating rumen epithelial development and function during weaning. Additional evaluation of gene expression in the rumen epithelium of adult cows ruminally infused with butyrate also suggested that observed changes in ESRRA mRNA expression in developing calf rumen may be mediated by increased butyrate concentration. Our results identify TGFB1 and ESRRA as likely transcriptional regulators of rumen epithelial development and energy metabolism, respectively, and provide targets for modulation of rumen development and function in the growing calf.

Improvement of the boron neutron capture therapy (BNCT) by the previous administration of the histone deacetylase inhibitor sodium butyrate for the treatment of thyroid carcinoma

We have shown that boron neutron capture therapy (BNCT) could be an alternative for the treatment of poorly differentiated thyroid carcinoma (PDTC). Histone deacetylase inhibitors (HDACI) like sodium butyrate (NaB) cause hyperacetylation of histone proteins and show capacity to increase the gamma irradiation effect. The purpose of these studies was to investigate the use of the NaB as a radiosensitizer of the BNCT for PDTC. Follicular thyroid carcinoma cells (WRO) and rat thyroid epithelial cells (FRTL-5) were incubated with 1 mM NaB and then treated with boronophenylalanine ¹⁰BPA (10 μg ¹⁰B ml⁻¹) + neutrons, or with 2, 4-bis (α,β-dihydroxyethyl)-deutero-porphyrin IX ¹⁰BOPP (10 μg ¹⁰B ml⁻¹) + neutrons, or with a neutron beam alone. The cells were irradiated in the thermal column facility of the RA-3 reactor (flux = (1.0 ± 0.1) × 10¹⁰ n cm⁻² s⁻¹). Cell survival decreased as a function of the physical absorbed dose in both cell lines. Moreover, the addition of NaB decreased cell survival (p < 0.05) in WRO cells incubated with both boron compounds. NaB increased the percentage of necrotic and apoptotic cells in both BNCT groups (p < 0.05). An accumulation of cells in G2/M phase at 24 h was observed for all the irradiated groups and the addition of NaB increased this percentage. Biodistribution studies of BPA (350 mg kg⁻¹ body weight) 24 h after NaB injection were performed. The in vivo studies showed that NaB treatment increases the amount of boron in the tumor at 2-h post-BPA injection (p < 0.01). We conclude that NaB could be used as a radiosensitizer for the treatment of thyroid carcinoma by BNCT.

[The development process of colon cancer centres]

Colon carcinomas are the most common malignant tumours in the Western world. Important findings about the overall quality of medical care have been reported in multi-centre observational studies. A quality enhancement of therapeutic care can be achieved by an additional increase in diagnostic and therapeutic measures in the interdisciplinary setting. The development of colon cancer centres improves the chance to objectively observe the results of medical care induced by the development of an interdisciplinary and cross-sectoral unit that includes a comprehensive medical care for patients. The implementation of the current medical findings based on evidence in clinical routine, the inspection of the usage of guidelines by external specialists as part of an audit and the continuous correction of analysed deficits in the course of treatment guarantee a continuous improvement of service.

Effects of stress on endocrine and metabolic processes and redirection: cross talk between subcellular compartments

Recent advances in genome analysis and biochemical pathway mapping have advanced our understanding of how biological systems have evolved over time. Protein and DNA marker comparisons suggest that several of these systems are both ancient in origin but highly conserved into today's evolved species. However, remnants of some of the more ancient functions of these chemical systems can run in conflict with the functions that those same pathways serve in complex organisms and tissue systems today. Relevant to the present topic, nitric oxide (NO) and superoxide anion (O(2)(•-)), ancient cellular molecules in evolutionary terms, are recognized today as both necessary for the well-being and stable health of cells but also injurious to cells as elaborated in conjunction with the cellular stress response. Why the dichotomy? This question underlies one of the basic issues challenging researchers as well as practitioners in their approach to disease management. The fundamental proinflammatory response of the innate immune system of the host is needed for pathogen control but can be injurious to tissues from "collateral damage" from NO- and O(2)(•-)-derived reactive molecules capable of affecting protein function via post-translational chemical modification. This review highlights newer aspects of the biochemistry of the NO- and O(2)(•-)-mediated innate proinflammatory response and further show how protein and tissue damage via overproduction of reactive nitrogen and oxygen intermediary molecules such as peroxynitrite (ONOO(-)) might be targeted to specific epitopes of proteins. Changes in the regulation of metabolism in response to proinflammatory disease states are discussed for GH signal transduction and tissue specificity.

Comparative evaluation of establishing a human gut microbial community within rodent models

The structure of the human gut microbial community is determined by host genetics and environmental factors, where alterations in its structure have been associated with the onset of different diseases. Establishing a defined human gut microbial community within inbred rodent models provides a means to study microbial-related pathologies, however, an in-depth comparison of the established human gut microbiota in the different models is lacking. We compared the efficiency of establishing the bacterial component of a defined human microbial community within germ-free (GF) rats, GF mice, and antibiotic-treated specific pathogen-free mice. Remarkable differences were observed between the different rodent models. While the majority of abundant human-donor bacterial phylotypes were established in the GF rats, only a subset was present in the GF mice. Despite the fact that members of the phylum Bacteriodetes were well established in all rodent models, mice enriched for phylotypes related to species of Bacteroides. In contrary to the efficiency of Clostridiales to populate the GF rat in relative proportions to that of the human-donor, members of Clostridia cluster IV only poorly colonize the mouse gut. Thus, the genetic background of the different recipient rodent systems (that is, rats and mice) strongly influences the nature of the populating human gut microbiota, determining each model's biological suitability.

Modeling the effects of estradiol and progesterone on the acute phase proinflammatory axis: variability in tumor necrosis factor-α, nitric oxide, and xanthine oxidase responses to endotoxin challenge in steers

The severity of host response in some diseases differs between sexes, and this dimorphism has been attributed to the immunomodulating effects of reproductive steroid hormones. In females, susceptibility to disease stress has been associated with reproductive status and attributed to prevailing progesterone (P4) or estrogen concentrations during different estrous cycle phases. Our objective was to clarify and define the effect of P4 or 17β-estradiol (E2) on the acute proinflammatory component of the innate immune system by administering these hormones to steers and evaluating initial and tolerance-associated concentration patterns of circulating proinflammatory immune response mediators after two consecutive lipopolysaccharide (LPS) challenges (LPS1 and LPS2, 6 d apart; 2.5 μg/kg BW, intravenously, Escherichia coli 055:B5). Plasma concentrations of the proinflammatory initiation cytokine tumor necrosis factor-α (TNF-α), nitrate+nitrite [NO(x), estimate of nitric oxide (NO) production], haptoglobin (HG; acute phase protein) and plasma xanthine oxidase activity (mediator of superoxide production) were measured. Crossbred steers (392 ± 7 kg) were fed a forage-concentrate diet (15% CP) to appetite and assigned to control (C; n = 7), P4 (n = 8), or E2 (n = 5) treatment. Jugular blood samples were obtained at 0, 1, 2, 3, 4, 7, and 24 h relative to each of the two LPS injections. For each proinflammatory biomarker, the area under the time by concentration curve (AUC) was used to evaluate and compare responses to the LPS challenge. Treatment with E2 disrupted LPS tolerance as observed in augmented plasma TNF-α (P < 0.01) and NO(x) (P < 0.01) responses to LPS2. Compared with C, P4 treatment decreased plasma NO(x) AUC after LPS2 (P < 0.05) and tended to reduce TNF-α AUC after LPS1 (P = 0.08). Plasma xanthine oxidase activity AUC was increased (P < 0.01) over C by E2 treatment after both LPS1 and LPS2. HG response to LPS1 within 24 h was not affected by any treatment. However, 6 d after LPS1 plasma HG concentration remained higher (P < 0.01) in steers treated with E2 than with C or P4. Results indicate that in cattle, P4 and E2, respectively, attenuate or amplify the response to LPS challenge at several points critical to the regulation of the progression of the proinflammatory cascade.

Effect of procainhydrochloride on phospholipase A2 catalytic activity in sodium taurocholate-induced acute experimental pancreatitis in rats

BACKGROUND

In human acute pancreatitis (AP) the local anaesthetic procainhydrochloride (procain-HCl) is given intravenously for pain treatment. Procain has been shown to inhibit catalytic activity of pancreatic (group I) phospholipase A2 (PLA2) and non-pancreatic (group II) PLA2. Both enzymes are important mediators for the local and systemic inflammatory process in AP. To determine the effect of procain, we examined serum and tissue levels of both types of PLA2 activity in the experimental rodent taurocholate model of AP.

METHODS

In 60 rats, severe pancreatitis was induced by taurocholate. Forty rats were treated with procain-HCl intravenously at a dosage of 2 mg/kg body weight/h either at or 1 h after induction of pancreatitis. Twenty rats served as controls. We measured catalytic activities of group I and group II PLA2 in serum and tissue samples of lung and pancreas.

RESULTS

Serum group II PLA2 catalytic activity was significantly reduced 3 and 6 h after AP induction in rats treated with procain-HCl (p < 0.001) in both treatment groups. In pancreatic and lung tissue, group II PLA2 catalytic activity was significantly reduced compared with normal values (p < 0.001).

CONCLUSION

Procain-HCl given intravenously either at or 1 h after induction of necrotizing pancreatitis significantly inhibits group II PLA2 catalytic activity in serum and tissues.

Variability in tumor necrosis factor-alpha, nitric oxide, and xanthine oxidase responses to endotoxin challenge in heifers: effect of estrous cycle stage

The severity of host response to some disease agents differs between sexes and this dimorphism has been attributed to the immunomodulating effects of steroid hormones. Our objective was to determine in heifers whether the phase of estrous cycle affected immune response mediators after endotoxin challenge (LPS, 2.5microg/kg BW, i.v.). Sixteen beef heifers (426+/-9kg) were reproductively synchronized with the two-injection protocol of dinoprost tromethamine (Lutalyse, Pfizer) to establish diestrus and estrus stages of the estrous cycle. Heifers were challenged with LPS on day 3 (E, estrus; n=8) or day 10 (D, diestrus, n=8) after the last i.m. injection of Lutalyse. In all heifers, plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) peaked 2h after LPS treatment (P<0.01) and returned to basal level by 7h. However, the integrated TNF-alpha response (area under the time x concentration curve, AUC) was greater in E than in D (P<0.05). Plasma concentrations of nitrate+nitrite (NO(x), an estimate of NO production) increased (P<0.01) in all heifers at 7 and 24h after LPS; plasma NO(x) AUC after LPS was greater in E than D (P<0.01). Plasma xanthine oxidase activity (XO, a mediator of superoxide production) responses were also greater in E than D (P<0.05). A companion LPS challenge study in steers validated that the protocol for and use of Lutalyse did not affect any of the immune parameters studied in heifers in response to LPS. Results indicate that the underlying physiological attributes of the estrus and diestrus phases of the estrous cycle constitute a major source of variability in the magnitude of proinflammatory response to bacterial toxins like LPS.

Modeling growth factor activity during proinflammatory stress: methodological considerations in assessing cytokine modulation of IGF binding proteins released by cultured bovine kidney epithelial cells

The present research was conducted to model potential mechanisms through which IGFBPs might be affected by a key proinflammatory response initiating cytokine tumor necrosis factor (TNF-)-alpha. Madin-Darby bovine kidney epithelial (MDBK) cells, known to release IGFBPs in response to several stimuli, were grown under several conditions and challenged with forskolin (F) or recombinant TNF-alpha for 24h. Forskolin increased IGFBP-3 gene expression and media content of BP-3 protein. TNF-alpha increased basal and augmented F-mediated IGFBP-3 gene expression. However, TNF-alpha effects on the measurable media content of IGFBPs were influenced by culture conditions; in the absence of added protease inhibitors (PIs) or sufficient media albumin concentration (high BSA, 1mg/ml), the effect of TNF-alpha was to decrease (P<0.02) measurable IGFBPs. In the presence of PI and high BSA, media IGFBP-3 levels were shown to be increased by TNF-alpha consistent with the gene expression data. Changes in media IGFBP-3 protease activity were examined further to explain the observed effects of TNF-alpha on production and destruction of IGFBPs in media. When recombinant human IGFBP-3 (500 ng/ml) was added to PI-free, low BSA 100 microg/ml) media from TNF-treated MDBK cells, less than 10% of the BP-3 was recognizable by Western blot in 30 min; conversely, inclusion of High BSA and PI in media resulted in attenuation of the protease effect on the IGFBPs. The data suggest that the MDBK model of cellular response to proinflammatory stimulus is affected by culture conditions and that TNF-alpha affects media content of IGFBPs through effects on IGFBP gene expression coupled with degradation of IGFBPs via enhanced proteolytic enzyme release.

Effects of chlortetracycline and Synovex-S® on growth rate and on plasma growth hormone and thyroid hormone concentrations following administration of thyrotropin-releasing hormone and GH-releasing hormone in beef steers

Twenty-four Angus steers (365 kg ± 4) were assigned randomly to a 2 × 2 factorial arrangement of treatments of either 0 or 350 mg chlortetracycline d-1, with or without Synovex-S to test the effects of chlortetracycline (CTC) and estrogenic implant on release of growth hormone (GH) and thyroid hormones. Steers received ad libitum a concentrate-forage diet over a 112-d feeding study, and growth and carcass characteristics were determined. On days 30, 56, and 106, steers received an injection, via jugular catheter, of 1.0 µg kg-1 BW thyrotropin-releasing hormone (TRH) + 0.1 µg kg-1 BW GH-releasing hormone (GHRH) and blood was collected from -30 to 360 min post-injection. Overall, compared with non-implanted steers, Synovex-S increased (P ≤ 0.009) rate and efficiency of gain, decreased (P = 0.05) time to peak for GH concentrations, whereas baseline concentrations of thyroid-stimulating hormone (TSH) were increased (P = 0.03). Additionally, the TSH response curve (P ≤ 0.05) and magnitude of triiodothyronine (T3; P = 0.01) response were greater following TRH + GHRH challenge for implanted versus nonimplanted steers. There were no main effects of CTC; however, CTC attenuated (P ≤ 0.05) the effects of implant on T3 release, slaughter weight, and carcass composition. In conclusion, Synovex-S alone increased BW gain and enhanced the response of GH, TSH, and T3 to a TRH + GHRH challenge, whereas CTC alone did not affect rate and composition of gain or release of pituitary and thyroid hormones. However, CTC appeared to mitigate the effects of implant on T3 release and carcass composition. Key words: Growth hormone, thyroid, estrogen, chlortetracycline, bovine, growth