Application of an immunosensor for the detection of the β-lactam antibiotic, cephalexin

Public concern surrounding antibiotic contamination in food and food products has made it imperative to develop analytical methods for their detection. Polyclonal antibodies were used in the development of a surface plasmon resonance (SPR)-based inhibition immunoassay for cephalexin. A conjugate consisting of cephalexin-bovine serum albumin (BSA) was immobilized on the dextran gel surface of the sensor chip. Binding/regeneration studies of antibody to immobilized cephalexin were studied and dissociation of the antibody from the immobilized cephalexin was easily achieved with 10 mmol l^-1 NaOH. Forty surface regeneration cycles were carried out and found to be reproducible with only a 7.4% decrease in binding over this number of regenerations. Model inhibition immunoassays for cephalexin were developed in PBS and spiked milk samples with detection ranges of 4.88 to 2,500 ng ml^-1 and 244 to 3,906 pg ml^-1, respectively.     

Surgical treatment of Pancoast tumours.

Due to its localisation in the apex of the lung with invasion of the lower part of the brachial plexus, first ribs, vertebrae, subclavian vessels or stellate ganglion, a superior sulcus tumour causes characteristic symptoms, like arm or shoulder pain or Horner's syndrome. If rib invasion is the only feature, lysis of the rib must be evident on the chest radiograph; otherwise the tumour cannot be defined as a Pancoast tumour. It is important to adequately stage the tumour, because staging significantly influences survival. Survival is better for T3 than T4 tumours and mediastinal lymph node involvement has been found to be a negative prognostic factor. Also Horner's syndrome and incompleteness of resection worsen survival. The management of superior sulcus tumours has evolved over the past 50 years. Before 1950 it was considered to be inoperable and uniformly fatal. Shaw and Paulson introduced combined modality treatment and for many years, this combination of radiotherapy and surgery was the treatment of choice with a mean 5-year survival of approximately 30%. Postoperative radiotherapy or brachytherapy does not improve survival in patients with complete or incomplete resection. The tumour can be resected through the classic posterior Shaw-Paulson approach or the newer anterior transcervical approach, introduced by Dartevelle. This method facilitates better exposure of the extreme apex of the lung, brachial plexus and subclavian vessels. Regarding the extent of pulmonary resection, en bloc resection of the involved ribs with a lobectomy is recommended. Recent multimodality studies, involving chemoradiotherapy and surgical resection, show promising results regarding completeness of resection, local recurrence and survival, provided that appropriate staging has been carried out. However, careful patient selection and adequate perioperative management with protection of the bronchial stump or anastomosis are important to achieve reasonable rates of morbidity and mortality. As brain metastases remain one of the most common forms of relapse, further studies are needed to examine the role of prophylactic cranial irradiation in patients with complete resection. Also the addition of other chemotherapy agents or biologic agents such as angiogenesis inhibitors or tyrosine kinase inhibitors gives a new perspective in the treatment of Pancoast tumours.     

Different levels of natural antibodies in chickens divergently selected for specific antibody responses

We studied the presence of Natural antibodies in plasma samples from individual birds from selected chicken lines at young and old age. Binding, specificity, and relative affinity to various antigens were determined in plasma from non-immunized female chickens at 5 weeks of age, and in plasma obtained from the same chickens one year later using indirect two-step ELISA. Birds were from three different lines. The lines were divergently selected for either high (H line) or low (L line) antibody titers to Sheep Red Blood Cells at 5 weeks of age, next to a random bred control (C line). Binding of plasma immunoglobulins (Ig) from all three lines was found with chicken-egg-white protein (CEP), ovalbumin (OVA), myoglobin (MYO), thyroglobulin (THYRO), keyhole limpet hemocyanin (KLH), bovine serum albumin (BSA), and transferrin (TRANS). Significantly higher binding to most antigens was found with plasma Ig from adult birds from the H line as compared to plasma Ig from the L line, whereas binding of plasma Ig from C-line birds was in between or similar to the H or L line, respectively. Binding of Ig to all antigens in all three lines was significantly higher in plasma obtained at one year of age as compared to plasma obtained at 5 weeks of age. A competitive ELISA with homologous and heterologous antigens was used for determining specificity of the antigen-binding antibodies. Nai;ve plasma samples were characterized by a broad binding to all antigens tested. Inhibition of binding to specific antigens was possible with a broad range of heterologous antigens, but highest competition of binding was obtained with homologous antigen. Both linear regression analysis of serial dilutions of the plasma Ig binding the antigens, as well as competitive ELISA with homologous antigen indicated that plasma Ig from the H line and plasma Ig from the L line had similar affinity characteristics to the antigens tested with the exception of OVA and KLH. Pooled non-immune plasma from H line birds bound to CEP, OVA, THYRO, TRANS, MYO, KLH, and salt-precipitated extracts and supernatants of extracts from chicken heart, spleen, liver, brain, bursa, thymus, and kidney, respectively, as determined by Western blotting. The increasing presence of antibodies in nai;ve chicken plasma binding heterologous and homologous (tissue) antigens indicates the presence of Natural antibodies in poultry. Apart from age, increasing levels of Natural antibodies may be related with the genetically based magnitude of specific antibody levels in the chicken lines studied.     

Variability in acquired resistance of Pasteurella and Mannheimia isolates from the nasopharynx of calves, with particular reference to different herd types

To measure the level of antimicrobial resistance in potential bovine respiratory pathogens at different production types, nasal swabs were collected from 57 calves of 13 dairy herds, 150 calves of 9 beef cattle herds, and 289 calves of 5 high-density veal calf herds and investigated for the presence of Pasteurellaceae. All calves were less than 6 months old. Susceptibilities of the Pasteurella and Mannheimia isolates to eight antimicrobials were determined using an agar dilution method. P. multocida (37.3%) and hemolytic Mannheimia organisms (M. haemolytica sensu lato) (6.3%) were the most frequently detected organisms. The overall prevalence of isolates resistant to at least one antimicrobial from the dairy, beef, and veal calves were 17.6% (6/34), 21.9% (14/64), and 71.9% (64/89), respectively. In isolates obtained on the veal calf herds, acquired resistance to ampicillin, oxytetracycline, potentiated sulfonamides, gentamicin, tilmicosin, and enrofloxacin was frequently present, and 32.6% of these isolates were resistant to more than two of the tested antimicrobials. Resistance to ceftiofur and florfenicol was not detected. A substantial within-herd variability of species diversity and resistance profiles among isolates belonging to the genera Pasteurella and Mannheimia was found among the isolates of the veal calf farms.     

Acute cytomegalovirus infection modulates the intestinal microbiota and targets intestinal epithelial cells

Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis.     

Investigation of Bamboo Fibrous Tensile Strength Using Modified Weibull Distribution

Ethiopia has a large coverage of bamboo plants that are used for furniture making and house building. So far, researchers have not studied the strength of Ethiopian bamboo fibers, which are utilized for composite applications. The current study measured the strength of bamboo fibers based on various testing lengths and calculated the predictive tensile strength using a modified Weibull distribution. Moreover, the quality of the extraction machine is evaluated based on shape and sensitivity parameters. This research paper incorporates the coefficient of variation of the fiber diameters, considering the defects distribution through the length for measuring the predictive strength of the fibers. The fiber diameters were calculated using the area weight methods, which had its density measured using a Pycnometer. It has been examined that as the testing gauge length and coefficient variation of fiber diameter simultaneously increased, the tensile strength of the bamboo fibers decreased. The shape parameter, sensitivity parameter, and characteristic strength of Injibara bamboo (Y. alpina) are 6.02–7.83, 0.63, and 459–642 MPa, whereas Kombolcha bamboo (B. oldhamii) are 5.87–10.21, 0.33, and 408–638 MPa, as well as Mekaneselam bamboo (Y. alpina) are 5.86–9.63, 0.33 and 488–597 MPa, respectively.     

Sequential organ failure predicts mortality of patients with a haematological malignancy needing intensive care

OBJECTIVES: Poor survival of patients with a haematological malignancy admitted to the intensive care unit (ICU) prompts for proper admission triage and prediction of ICU treatment failure and long-term mortality. We therefore tried to find predictors of the latter outcomes. METHODS: A retrospective analysis of charts and a prospective follow-up study were done, of haemato-oncological patients, admitted to our ICU in a 7-year period with a follow-up until 2 yr thereafter. Clinical parameters during the first four consecutive days were taken to calculate the simplified acute physiology (SAPS II) and the sequential organ failure assessment (SOFA) scores, of proven predictive value in general ICU populations. RESULTS: From a total of 58 patients (n = 47 with acute myelogenous leukaemia or non-Hodgkin lymphoma), admitted into ICU mostly because of respiratory insufficiency, sepsis, shock or combinations, 36 patients had died during their stay in the ICU. Of ICU survivors (n = 22), 20 patients died during follow-up so that the 1-year survival rate was only 12%. The SAPS II and particularly the SOFA scores were of high predictive value for ICU and long-term mortality. CONCLUSIONS: Patients with life-threatening complications of haematological malignancy admitted to ICU ran a high risk for death in the ICU and on the long-term, and the risk can be well predicted by SOFA. The latter may help us to decide on intensive care in individual cases, in order to avoid potentially futile care for patients with a SOFA score of 15 or higher.     

Molecular discrimination of atypical bovine spongiform encephalopathy strains from a geographical region spanning a wide area in Europe

Transmissible spongiform encephalopathy strains can be differentiated by their behavior in bioassays and by molecular analyses of the disease-associated prion protein (PrP) in a posttranslationally transformed conformation (PrPSc). Until recently, isolates from cases of bovine spongiform encephalopathy (BSE) appeared to be very homogeneous. However, a limited number of atypical BSE isolates have recently been identified upon analyses of the disease-associated proteinase K (PK) resistance-associated moiety of PrPSc (PrPres), suggesting the existence of at least two additional BSE PrPres variants. These are defined here as the H type and the L type, according to the higher and lower positions of the nonglycosylated PrPres band in Western blots, respectively, compared to the position of the band in classical BSE (C-type) isolates. These molecular PrPres variants, which originated from six different European countries, were investigated together. In addition to the migration properties and glycosylation profiles (glycoprofiles), the H- and L-type isolates exhibited enhanced PK sensitivities at pH 8 compared to those of the C-type isolates. Moreover, H-type BSE isolates exhibited differences in the binding of antibodies specific for N- and more C-terminal PrP regions and principally contained two aglycosylated PrPres moieties which can both be glycosylated and which is thus indicative of the existence of two PrPres populations or intermediate cleavage sites. These properties appear to be consistent within each BSE type and independent of the geographical origin, suggesting the existence of different BSE strains in cattle. The choice of three antibodies and the application of two pHs during the digestion of brain homogenates provide practical and diverse tools for the discriminative detection of these three molecular BSE types and might assist with the recognition of other variants.     

Glucose homeostasis and safety in patients with acromegaly converted from long-acting octreotide to pegvisomant

CONTEXT: In clinical practice, patients with acromegaly may be switched from therapy with long-acting somatostatin analogs to pegvisomant. The effect of changing therapies on glucose homeostasis and safety has not been reported. OBJECTIVES: The objectives of this study were to monitor changes in IGF-I levels, glycemic control, and safety, particularly liver function and tumor size. DESIGN: This was a multicenter, open-label, 32-wk trial study. SETTING: The study was performed at outpatient clinics. PATIENTS: Fifty-three patients with acromegaly previously treated with octreotide long-acting release (LAR) participated in this study. Intervention: Pegvisomant (10 mg/d) was initiated 4 wk after the last dose of octreotide LAR and was adjusted based on serum IGF-I concentrations at wk 12, 20, and 28. MAIN OUTCOME MEASURES: The main outcome measures were changes in IGF-I, glycosylated hemoglobin A1c (HbA1c), fasting plasma glucose, and safety during the first 12 wk after conversion. RESULTS: At the end of pegvisomant treatment, IGF-I was normalized in 78% of patients. At wk 32, median fasting glucose concentration and HbA1c were reduced (-1.4 mmol/liter and -0.4%, respectively; both P < or = 0.0001) in the study population. Improvements in glycemic control occurred in patients with normal IGF-I concentrations at wk 4 [n = 15; fasting glucose, -1.7 mmol/liter (P < or = 0.0001); HbA1c -0.2% (P = 0.03)]. Decreases in fasting glucose and HbA1c levels were observed in patients with and without diabetes. HbA1c was reduced by more than 1.0% in patients with diabetes. Median pituitary tumor volume did not change, although tumor volume increased in two patients with macroadenomas. CONCLUSIONS: Conversion from octreotide LAR to pegvisomant was safe and well tolerated. Improved glycemic control indicates that pegvisomant should be considered in patients with acromegaly and diabetes.     

Basal cerebral blood flow is dependent on the nitric oxide pathway in elderly but not in young healthy men

OBJECTIVE: Brain perfusion is tightly regulated over a wide range of blood pressures by local regulation of cerebral blood flow (CBF). Ageing is associated with impaired CBF and impaired nitric oxide mediated vasodilator responses. The role of nitric oxide in the regulation of basal CBF in young and older subjects was investigated, using the nitric oxide synthase inhibitor L-NMMA as pharmacological tool. METHODS: We used a gradient echo phase-contrast magnetic resonance imaging technique to investigate the role of nitric oxide in the regulation of cerebral blood flow in young (25+/-7.1 years; n=8) and old (78+/-6.6 years; n=7) volunteers. The study was performed in a double-blinded fashion and consisted of two study days. On one day the effects of the intravenously infused L-NMMA on CBF and blood pressure was measured and on the other day the effects of a matching placebo. RESULTS: Basal CBF was significantly lower in old compared to young subjects (590+/-20 vs 704+/-20 ml/min), while the cerebral vascular resistance (CVR) levels were significantly higher (0.15+/-0.01 (arbitrary units) vs 0.12+/-0.01, respectively). Infusion of L-NMMA significantly increased mean arterial pressure in both groups (2.8+/-1.2 mmHg; p=0.02 in the young and in the old subjects 5.6+/-1.1 mmHg; p<0.001). Infusion of L-NMMA significantly decreased CBF (49+/-12 ml/min; p<0.001) and increased CVR (0.02+/-0.004; p<0.001) in the old subjects but did not significantly influence cerebral circulation in the young subjects. CONCLUSION: We conclude that compared to young subjects, in old people CBF is impaired, and dependent on the intactness of the nitric oxide pathway.