Effect of Different Antibiotics and Non-Steroidal Anti-Inflammatory Drugs on the Growth of Lactobacillus casei Shirota

The purpose of this study was to investigate whether some non-steroidal anti-inflammatory drugs (NSAIDs) could cause inhibition of the growth of Lactobacillus casei Shirota (LcS) or whether this microorganism is able to use some of them as the sole carbon source, considering that the simultaneous consumption of NSAIDs and a dairy drink fermented with LcS could help to prevent the appearance or improve the healing of gastric ulcers. Acetylsalicylic acid (ASA), sodium acetylsalicylate (SAS), acetaminophen, sodium naproxen, and sodium ibuprofen were added as the sole carbon source to a basal medium and tested for biodegradation by LcS. The same NSAIDs were added in different concentrations to disks and plated on MRS Agar to test the possible inhibitory effect of these compounds on LcS. Also, the resistance of LcS to 12 different antibiotics was studied on MRS agar. None of the NSAIDs tested could be used by LcS as the sole carbon source at the assayed concentrations. In the case of the disk diffusion method, sodium naproxen showed inhibition zones for the 500-μg disks and sodium ibuprofen was inhibitory for the 250- and 500-μg disks. However, when the macrobroth dilution method was used, the growth of LcS was inhibited by ASA, SAS, acetaminophen, and sodium ibuprofen. This strain showed resistance to the antibiotics sulfamethoxazole with trimethoprim, pefloxacin, and gentamicin. This is the first study on the effect of NSAIDs on probiotic bacteria. The results of the biodegradation test indicate that the simultaneous consumption of NSAIDs and a dairy beverage with LcS is not likely to change the bioavailability of the drugs.     

Prevalence and Phase Variable Expression Status of Two Autotransporters,NalP and MspA,in Carriage and Disease Isolates of Neisseria meningitidis

Neisseria meningitidis is a human nasopharyngeal commensal capable of causing life-threatening septicemia and meningitis. Many meningococcal surface structures, including the autotransporter proteins NalP and MspA, are subject to phase variation (PV) due to the presence of homopolymeric tracts within their coding sequences. The functions of MspA are unknown. NalP proteolytically cleaves several surface-located virulence factors including the 4CMenB antigen NhbA. Therefore, NalP is a phase-variable regulator of the meningococcal outer membrane and secretome whose expression may reduce isolate susceptibility to 4CMenB-induced immune responses. To improve our understanding of the contributions of MspA and NalP to meningococcal-host interactions, their distribution and phase-variable expression status was studied in epidemiologically relevant samples, including 127 carriage and 514 invasive isolates representative of multiple clonal complexes and serogroups. Prevalence estimates of >98% and >88% were obtained for mspA and nalP, respectively, with no significant differences in their frequencies in disease versus carriage isolates. 16% of serogroup B (MenB) invasive isolates, predominately from clonal complexes ST-269 and ST-461, lacked nalP. Deletion of nalP often resulted from recombination events between flanking repetitive elements. PolyC tract lengths ranged from 6–15 bp in nalP and 6–14 bp in mspA. In an examination of PV status, 58.8% of carriage, and 40.1% of invasive nalP-positive MenB isolates were nalP phase ON. The frequency of this phenotype was not significantly different in serogroup Y (MenY) carriage strains, but was significantly higher in invasive MenY strains (86.3%; p<0.0001). Approximately 90% of MenB carriage and invasive isolates were mspA phase ON; significantly more than MenY carriage (32.7%) or invasive (13.7%) isolates. This differential expression resulted from different mode mspA tract lengths between the serogroups. Our data indicates a differential requirement for NalP and MspA expression in MenB and MenY strains and is a step towards understanding the contributions of phase-variable loci to meningococcal biology.     

Imaging Axl expression in pancreatic and prostate cancer xenografts

The receptor tyrosine kinase Axl is overexpressed in and leads to patient morbidity and mortality in a variety of cancers. Axl–Gas6 interactions are critical for tumor growth, angiogenesis and metastasis. The goal of this study was to investigate the feasibility of imaging graded levels of Axl expression in tumors using a radiolabeled antibody. We radiolabeled anti-human Axl (Axl mAb) and control IgG1 antibodies with ¹²⁵I with high specific radioactivity and radiochemical purity, resulting in an immunoreactive fraction suitable for in vivo studies. Radiolabeled antibodies were investigated in severe combined immunodeficient mice harboring subcutaneous CFPAC (Axl^high) and Panc1 (Axl^low) pancreatic cancer xenografts by ex vivo biodistribution and imaging. Based on these results, the specificity of [¹²⁵I]Axl mAb was also validated in mice harboring orthotopic Panc1 or CFPAC tumors and in mice harboring subcutaneous 22Rv1 (Axl^low) or DU145 (Axl^high) prostate tumors by ex vivo biodistribution and imaging studies at 72 h post-injection of the antibody. Both imaging and biodistribution studies demonstrated specific and persistent accumulation of [¹²⁵I]Axl mAb in Axl^high (CFPAC and DU145) expression tumors compared to the Axl^low (Panc1 and 22Rv1) expression tumors. Axl expression in these tumors was further confirmed by immunohistochemical studies. No difference in the uptake of radioactivity was observed between the control [¹²⁵I]IgG1 antibody in the Axl^high and Axl^low expression tumors. These data demonstrate the feasibility of imaging Axl expression in pancreatic and prostate tumor xenografts.     

Dynamics of the DNA repair proteins WRN and BLM in the nucleoplasm and nucleoli

We have investigated the mobility of two EGFP-tagged DNA repair proteins, WRN and BLM. In particular, we focused on the dynamics in two locations, the nucleoli and the nucleoplasm. We found that both WRN and BLM use a “DNA-scanning” mechanism, with rapid binding–unbinding to DNA resulting in effective diffusion. In the nucleoplasm WRN and BLM have effective diffusion coefficients of 1.62 and 1.34 μm²/s, respectively. Likewise, the dynamics in the nucleoli are also best described by effective diffusion, but with diffusion coefficients a factor of ten lower than in the nucleoplasm. From this large reduction in diffusion coefficient we were able to classify WRN and BLM as DNA damage scanners. In addition to WRN and BLM we also classified other DNA damage proteins and found they all fall into one of two categories. Either they are scanners, similar to WRN and BLM, with very low diffusion coefficients, suggesting a scanning mechanism, or they are almost freely diffusing, suggesting that they interact with DNA only after initiation of a DNA damage response.     

A prospective study for the association of Helicobacter pylori infection to a multidimensional measure for recurrent abdominal pain in children

BACKGROUND: There is a controversial association between Helicobacter pylori infection and recurrent abdominal pain (RAP) in childhood and inconsistent information on specific symptomatology of the infection. AIMS: To examine the prevalence of H. pylori infection among children with RAP compared to asymptomatic children. METHODS: Two prospective studies were conducted. The first study enrolled 223 children diagnosed with RAP from two pediatric gastroenterology clinics in Houston, Texas. Children were qualified if they were identified by their physician as having RAP. A new multidimensional measure for RAP (MM-RAP) consisting of four scales (pain intensity scale, symptoms scale, disability scale, and satisfaction scale) was administered to each child/parent. The second study enrolled 330 asymptomatic children from the same community who did not have any upper gastrointestinal symptoms. Symptomatic and asymptomatic children underwent (13)C-urea breath testing. RESULTS: In the first study, the prevalence of H. pylori in children with RAP was 11% and fell with age from 20% at age < or = 5 years to 7% for children > 10 years (OR = 2.7, 95% CI = 0.7-11.2). There was no association between the mother's educational level and H. pylori prevalence; (12% among children whose mothers completed college versus 11% among those who had elementary school, p = .8). No relationship was found between H. pylori and mean scores of the RAP scales. In the second study, the prevalence of H. pylori in asymptomatic children was 17% and increased with age from 11% for children < or = 5 years to 40% for children > 10 years (OR = 5.4, 95% CI = 2.0-13.8). The mother's educational level was inversely correlated with H. pylori (OR = 3.0, 95% CI = 2.2-6.1, p < .01). CONCLUSIONS: The epidemiologic patterns of H. pylori infection differed significantly between symptomatic and asymptomatic children. Younger children suffering from RAP are more likely to be infected with H. pylori than older children with the same complaint, suggesting that early acquisition may manifest in symptoms that lead to clinic visits.     

Environmental factors regulate the effects of roach Rutilus rutilus and pike Esox lucius on perch Perca fluviatilis populations in small boreal forest lakes

In this study of 18 small boreal forest lakes, the effects of abiotic and biotic factors (roach Rutilus rutilus and pike Esox lucius) on various population variables of perch Perca fluviatilis were examined. As a single variable, the gillnet catch per unit effort (CPUE) of R. rutilus was negatively related to the mean mass of small (< 200 mm) and the growth rate of young (1–2 years) P. fluviatilis. The mean mass of large (≥ 200 mm) P. fluviatilis was the highest at intermediate CPUE of R. rutilus. Redundancy analysis including environmental factors and P. fluviatilis population variables suggested that ‘predation–productivity–humus' gradient affected P. fluviatilis populations by decreasing the CPUE and mean mass of small individuals but increasing these variables of large individuals. The CPUE of R. rutilus and lake area had a negative effect on small and a positive effect on large P. fluviatilis growth rate. In small boreal forest lakes, P. fluviatilis populations are affected by the partially opposite forces of competition by R. rutilus and predation by E. lucius, and the intensity of these interactions is regulated by several environmental factors.     

Tick-susceptible Bos taurus cattle display an increased cellular response at the site of larval Rhipicephalus (Boophilus) microplus attachment, compared with tick-resistant Bos indicus cattle

Cattle demonstrate divergent and heritable phenotypes of resistance and susceptibility to infestation with the cattle tick Rhipicephalus (Boophilus) microplus. Bos indicus cattle are generally more resistant to tick infestation than Bos taurus breeds although large variations in resistance can occur within subspecies and within breed. Increased tick resistance has been previously associated with an intense hypersensitivity response in B. taurus breeds; however, the mechanism by which highly resistant B. indicus cattle acquire and sustain high levels of tick resistance remains to be elucidated. Using the commercially available Affymetrix microarray gene expression platform, together with histological examination of the larval attachment site, this study aimed to describe those processes responsible for high levels of tick resistance in Brahman (B. indicus) cattle that differ from those in low-resistance Holstein-Friesian (B. taurus) cattle. We found that genes involved in inflammatory processes and immune responsiveness to infestation by ticks, although up-regulated in tick-infested Holstein-Friesian cattle, were not up-regulated in Brahman cattle. In contrast, genes encoding constituents of the extracellular matrix were up-regulated in Brahmans. Furthermore, the susceptible Holstein-Friesian animals displayed a much greater cellular inflammatory response at the site of larval R. microplus attachment compared with the tick-resistant Brahman cattle.     

1H NMR metabonomics approach to the disease continuum of diabetic complications and premature death

Subtle metabolic changes precede and accompany chronic vascular complications, which are the primary causes of premature death in diabetes. To obtain a multimetabolite characterization of these high‐risk individuals, we measured proton nuclear magnetic resonance (¹H NMR) data from the serum of 613 patients with type I diabetes and a diverse spread of complications. We developed a new metabonomics framework to visualize and interpret the data and to link the metabolic profiles to the underlying diagnostic and biochemical variables. Our results indicate complex interactions between diabetic kidney disease, insulin resistance and the metabolic syndrome. We illustrate how a single ¹H NMR protocol is able to identify the polydiagnostic metabolite manifold of type I diabetes and how its alterations translate to clinical phenotypes, clustering of micro‐ and macrovascular complications, and mortality during several years of follow‐up. This work demonstrates the diffuse nature of complex vascular diseases and the limitations of single diagnostic biomarkers. However, it also promises cost‐effective solutions through high‐throughput analytics and advanced computational methods, as applied here in a case that is representative of the real clinical situation.