Hydrophilic interaction liquid chromatography (HILIC)—a powerful separation technique

Hydrophilic interaction liquid chromatography (HILIC) provides an alternative approach to effectively separate small polar compounds on polar stationary phases. The purpose of this work was to review the options for the characterization of HILIC stationary phases and their applications for separations of polar compounds in complex matrices. The characteristics of the hydrophilic stationary phase may affect and in some cases limit the choices of mobile phase composition, ion strength or buffer pH value available, since mechanisms other than hydrophilic partitioning could potentially occur. Enhancing our understanding of retention behavior in HILIC increases the scope of possible applications of liquid chromatography. One interesting option may also be to use HILIC in orthogonal and/or two-dimensional separations. Bioapplications of HILIC systems are also presented

Carnivore Translocations and Conservation: Insights from Population Models and Field Data for Fishers (Martes pennanti)

Translocations are frequently used to restore extirpated carnivore populations. Understanding the factors that influence translocation success is important because carnivore translocations can be time consuming, expensive, and controversial. Using population viability software, we modeled reintroductions of the fisher, a candidate for endangered or threatened status in the Pacific states of the US. Our model predicts that the most important factor influencing successful re-establishment of a fisher population is the number of adult females reintroduced (provided some males are also released). Data from 38 translocations of fishers in North America, including 30 reintroductions, 5 augmentations and 3 introductions, show that the number of females released was, indeed, a good predictor of success but that the number of males released, geographic region and proximity of the source population to the release site were also important predictors. The contradiction between model and data regarding males may relate to the assumption in the model that all males are equally good breeders. We hypothesize that many males may need to be released to insure a sufficient number of good breeders are included, probably large males. Seventy-seven percent of reintroductions with known outcomes (success or failure) succeeded; all 5 augmentations succeeded; but none of the 3 introductions succeeded. Reintroductions were instrumental in reestablishing fisher populations within their historical range and expanding the range from its most-contracted state (43% of the historical range) to its current state (68% of the historical range). To increase the likelihood of translocation success, we recommend that managers: 1) release as many fishers as possible, 2) release more females than males (55–60% females) when possible, 3) release as many adults as possible, especially large males, 4) release fishers from a nearby source population, 5) conduct a formal feasibility assessment, and 6) develop a comprehensive implementation plan that includes an active monitoring program

Revisiting the B-cell compartment in mouse and humans: more than one B-cell subset exists in the marginal zone and beyond.

International audienceABSTRACT: The immunological roles of B-cells are being revealed as increasingly complex by functions that are largely beyond their commitment to differentiate into plasma cells and produce antibodies, the key molecular protagonists of innate immunity, and also by their compartmentalisation, a more recently acknowledged property of this immune cell category. For decades, B-cells have been recognised by their expression of an immunoglobulin that serves the function of an antigen receptor, which mediates intracellular signalling assisted by companion molecules. As such, B-cells were considered simple in their functioning compared to the other major type of immune cell, the T-lymphocytes, which comprise conventional T-lymphocyte subsets with seminal roles in homeostasis and pathology, and non-conventional T-lymphocyte subsets for which increasing knowledge is accumulating. Since the discovery that the B-cell family included two distinct categories - the non-conventional, or extrafollicular, B1 cells, that have mainly been characterised in the mouse; and the conventional, or lymph node type, B2 cells - plus the detailed description of the main B-cell regulator, FcγRIIb, and the function of CD40+ antigen presenting cells as committed/memory B-cells, progress in B-cell physiology has been slower than in other areas of immunology. Cellular and molecular tools have enabled the revival of innate immunity by allowing almost all aspects of cellular immunology to be re-visited. As such, B-cells were found to express "Pathogen Recognition Receptors" such as TLRs, and use them in concert with B-cell signalling during innate and adaptive immunity. An era of B-cell phenotypic and functional analysis thus began that encompassed the study of B-cell microanatomy principally in the lymph nodes, spleen and mucosae. The novel discovery of the differential localisation of B-cells with distinct phenotypes and functions revealed the compartmentalisation of B-cells. This review thus aims to describe novel findings regarding the B-cell compartments found in the mouse as a model organism, and in human physiology and pathology. It must be emphasised that some differences are noticeable between the mouse and human systems, thus increasing the complexity of B-cell compartmentalisation. Special attention will be given to the (lymph node and spleen) marginal zones, which represent major crossroads for B-cell types and functions and a challenge for understanding better the role of B-cell specificities in innate and adaptive immunology

Risk Factors for Breakthrough Pneumocystis carinii Pneumonia on Aerosol Pentamidine Prophylaxis

OBJECTIVE: To identify baseline characteristics of human immunodeficiency virus (HIV)-infected individuals on aerosol pentamidine for Pneumocystis carinii prophylaxis that are predictive of subsequent breakthrough Pneumocystis carinii pneumonia (PCP).DESIGN: Nested case-control study assembled from a cohort of patients enrolled in the Toronto aerosol pentamidine program.METHODS: Subjects were selected from a cohort of HIV-infected individuals were enrolled in a community based aerosol pentamidine program between May 1989 and May 1992 in Toronto, Ontario. Cases - individuals who had breakthrough PCP - were matched with up to two controls enrolled in the same week. Risk factors examined for development of PCP for both primary and secondary prophylaxisincluded age, sex, smoking history, evidence of bronchospasm during aerosol pentamidine administration (fall of forced expiratory volume [FEV] 15% or more), administration of salbutamol before aerosol pentamidine, pulmonary function tests including lung volumes, flow rates and diffusing capacity for carbon monoxide. In the primary prophylaxis group, CD4 count at enrolment and in the secondary prophylaxis group, time from the most recent episode of PCP to enrolment for aerosol pentamidine and total time from the most recent episode of PCP to breakthrough PCP were examined as additional risk factors.RESULTS: A total or 1344 patients we re enrolled in the aerosol pentamidine program, 78% for primary prophylaxis and 22% for secondary prophylaxis. At the time of census at the end or 1992 there had been 96 episodes or breakthrough PCP, 5% on primary prophylaxis and 14.5% on secondary prophylaxis. In the primary prophylaxis group, enrolment CD4 count was significantly lower in the cases developing breakthrough PCP: 116±74 compared with 175±85 cells/mm3 in the control group (P=0.001). There was no difference in any other variable. In the secondaryprophylaxis group, time from the most recent episode of PCP to initiation of aerosol pentamidine therapy was longer in the cases developing breakthrough PCP: mean delay 6.1±6.6 months compared with 3.1±2.1 in controls (P=0.02). There was no difference in the other variables examined.CONCLUSIONS: The results of this study support immune augmentation for patients receiving aerosol pentamidine for primary prophylaxis, and aerosol pentamidine should be recommenced as soon as possible following an episode of PCP, for secondary prophylaxis.Peer Reviewe

Interim Report on Drug Utilization Review of Community Acquired, Nursing Home Acquired and Nosocomial Pneumonia: Clinical, Bacteriological and Radiological Spectrum

OBJECTIVES: To review the epidemiology of community acquired, nursing home acquired and nosocomial pneumonia in terms of clinical. bacteriological and radiological features and to examine the spectrum of and response to antimicrobial agents used in its management.DESIGN: A retrospective review of all hospital records with pneumonia coded in the discharge diagnoses over a five-year period from April 1987 to March 1993.SETTING: University-affiliated, community-based hospital with a mixed primary to tertiary referral base.PATIENT SELECTION: Patients included in the study were all patients with a diagnosis of pneumonia as identified by computer records of diagnostic codes of all discharges: patients with a specific diagnosis of Pneumocystis carinii pneumonia were excluded. One thousand seven hundred and eighty-two patients out of 74.435 discharges over the five-year period met the inclusion criteria.RESULTS: The initial 1300 of the 1782 cases of pneumonia are included in this interim report. Mean age was 65 years (range 16 to 103) wilh 60% men and 40% women. Sixty-two percent of all cases were community acquired, 29% were hospital acquired and 9% were nursing home acquired. One thousand two hundred and sixty (97%) patients had al least one concomitant medical condition. mainly cardiac disease. alcoholism and chronic obstructive lung disease. Chest roentgenogram was abnormal in 98%. Cultures of sputum, bronchoalveolar lavage fluid, blood and/or serology revealed positive results in 785. The most common pathogens were Streptococcuspneumoniae (154). Haemophilus influenzae (147). Staphylococcus aureus (111) and Pseudomonas aeruginosa (100). In the group with community acquired pneumonia, S pneumoniae and H influenzae predominated. In the hospital acquired pneumonia group S aureus and P aeruginosa were more common. although S pneumoniae remains a significant pathogen. In the nursing home acquired pneumonia group. Gram-negative agents were the most common. The pattern of antimicrobial agents used, usually begun empirically when culture results are pending. showed that the majority of patients was treated with combination antibiotics for both Gram-positive and Gram-negative coverage. Ceftriaxone was usually prescribed with either erythromycin or clindamycin. In about half the patients. the ceftriaxone dose was 1 g per clay. Ninety-six (7%) patients developed complications of pneumonia and 207 (16%) patients required intensive care unit admission. Nine hundred and fifty-nine (73%) patients were cured or improved at time of discharge, 21 ( 1.5%) patients discharged themselves against medical advice and 320 (25%) patients died during admission to hospital, of whom 165 cases had pneumonia listed as a cause on the death certificate.CONCLUSIONS: Pneumonia remains a significant illness with high morbidity and mortality. Those affected and requiring hospitalization are elderly and ill. The most common pathogens overall continue to be S pneumoniae and H influenzae, although Gram-negative organisms and S aureus were also significant agents in nosocomial and nursing home acquired pneumonia. The high percentage of Gram-negative infections in the community acquired group has not been previously described and may represent a change in the pattern of pathogens affecting this group. Three of the 53 community acquired cases in whom P aeruginosa was implicated were detected on blood cultures and were definitely pathogens. Ten of the 53 patients had underlying bronchiectasis or cystic fibrosis and one patient had a history of hematogenous malignancy. Whether the finding of P aeruginosa represents true pathogenicity or colonization in the 53 cases is difficult to differentiate in a retrospective fashion. However. all but two received antibiotic therapy. and 10 of the 40 survivors in this subgroup received adequate coverage for pseudomonas. Although yield from routine investigations is only 60% (785 of 1300 patients in this study), cultures of blood and sputum should be sent in all patients as it may help to narrow choice of antimicrobial agents and aid in oral step-down selection . Only in select patients should serum serology and more costly and invasive procedures such as bronchoscopy and thoracocentesis be done. It appears that the current pattern of antimicrobial use is appropriate for management of pneumonia given the pattern of offending organisms seen. In the present study, pragmatic use of ceftriaxone at 1 g/24h in these sick patients appeared to result in a therapeutic outcome similar to other antibiotic combination therapy.Peer Reviewe

Community acquired, nursing home acquired and hospital acquired pneumonia: A five-year review of the clinical, bacteriological and radiological characteristics

Purpose: To assess the contemporary clinical, bacteriological and radiographic features of hospitalized patients with community acquired (ca), nursing home acquired (na) and hospital acquired pneumonia (ha) and to examine patient outcome

Community Acquired, Nursing Home Acquired and Hospital Acquired Pneumonia: A Five-Year Review of the Clinical, Bacteriological and Radiological Characteristics

Purpose: To assess the contemporary clinical, bacteriological and radiographic features of hospitalized patients with community acquired (ca), nursing home acquired (na) and hospital acquired pneumonia (ha) and to examine patient outcome.Patients and Methods: All hospital records of patients with pneumonia over a five-year period from April 1987 to March 1992 were reviewed retrospectively. Patients included in the study were all those with a diagnosis of pneumonia as identified by computer records of diagnostic codes at discharge; patients with a specific diagnosis of Pneumocystis carinii pneumonia were excluded. Of 74,435 discharges over the five-year period, 1782 patients met the inclusion criteria.Results: Charts of 1622 of the total 1782 cases were reviewed. Mean age was 64.4 years with 59.4% men and 40.6% women. Sixty-three per cent were ca, 28.5% were ha and 8.5% were na. A total of 1542 patients (95%) had at least one concomitant medical condition. Chest roentgenogram was abnormal in 97%. Common organisms isolated overall were Haemophilus influenzae (from 204 patients), Staphylococcus aureas (from 152 patients), Streptococcus pneumoniae (from 143 patients ), Escherichia coli (from 113 patients) and Pseudomonas aeruginosa (from 111 patients). H influenzae and S pneumoniae were most common in ca pneumonia, whereas S aureus and Gram-negative organisms were more common in the ha group and Gram-negative agents in the na group. One hundred and four patients developed complications. Fifteen per cent required intensive care unit admission. The average length of hospitalization in the ca and na groups was 17 days and in the ha group, 43 days. At time of discharge 1261 patients (78%) were cured or improved, and 361 patients (22%) died during the admission.Conclusions: These results suggest that hospitalization for pneumonia in the 1990s is primarily for elderly patients with significant co-morbidity. Although microbiology appears unchanged compared with earlier reports, the contemporary population is significantly sicker than previous cohorts. This may account for the persistently high morbidity and mortality despite better or newer antibiotics.Peer Reviewe

Interim Report on Drug Utilization Review of Community Acquired, Nursing Home Acquired and Nosocomial Pneumonia: Clinical, Bacteriological and Radiological Spectrum

OBJECTIVES: To review the epidemiology of community acquired, nursing home acquired and nosocomial pneumonia in terms of clinical. bacteriological and radiological features and to examine the spectrum of and response to antimicrobial agents used in its management