<Emphasis Type="Italic">Kocuria kristinae</Emphasis> infection associated with acute cholecystitis

Background  

Kocuria, previously classified into the genus of Micrococcus, is commonly found on human skin. Two species, K. rosea and K. kristinae, are etiologically associated with catheter-related bacteremia.     

P-selectin mediates spontaneous leukocyte rolling in vivo

Rolling represents the initial step leading to leukocyte extravasation from blood vessels during an inflammatory reaction. In vitro studies indicate that P-selectin could be one of the ligands on endothelium involved in the rolling phenomenon, although the molecular determinants responsible for this transient attachment in vivo are still undefined. Our objectives were to develop a blocking monoclonal antibody against canine P-selectin and to use it to investigate the role of P-selectin in leukocyte rolling in vivo using the technique of intravital microscopy. P-selectin was immunoaffinity purified from canine platelets and used for the production of monoclonal antibodies. One of the hybridomas generated, MD6, was shown by enzyme-linked immunosorbent assay and by flow cytometry to bind preferentially to stimulated platelets and to completely prevent binding of stimulated platelets to neutrophils. Visualization of canine mesenteric venules by intravital microscopy showed that administration of MD6 resulted in a marked inhibition in the number of rolling leukocytes (18.96 +/- 9.92 v 156.40 +/- 19.50 leukocytes/min, P < .05; 88.3% +/- 6.0% inhibition). Control antibody MD3 (which recognizes a nonfunctional epitope of canine P- selectin) had no effect on the number of rolling leukocytes or on their rolling velocity. These results show for the first time that P-selectin plays an essential role in leukocyte rolling in vivo, and therefore may be a key participant of the inflammatory response.     

Heparin cofactor II-proteinase reaction products exhibit neutrophil chemoattractant activity

The physiologic function of the plasma glycoprotein heparin cofactor II (HCII) is not well understood. An in vivo role for thrombin (IIa) inhibition by HCII in the presence of certain glycosaminoglycans (dermatan sulfate and heparin) can be proposed. Many proteins, such as complement components, can be proteolyzed to generate secondary bioactive molecules. HCII is a substrate for the human neutrophil (PMN) proteinases cathepsin G (CG) and elastase (LE). We found that degradation of HCII by CG or LE generated products with potent PMN chemotactic activity, which did not stimulate the PMN oxidative burst. Our results suggest that HCII may be a physiologic regulator of the acute inflammatory response.     

Infrequent alterations of the RAR alpha gene in acute myelogenous leukemias, retinoic acid-resistant acute promyelocytic leukemias, myelodysplastic syndromes, and cell lines

Retinoids are important regulators of cell growth and differentiation in vitro and in vivo and they exert their biologic activities by binding to nuclear retinoic acid receptors (RARs; alpha, beta, and gamma) and retinoid X receptors (RXRs; alpha, beta, and gamma). All- trans retinoic acid (RA) induces complete remission in patients with acute promyelocytic leukemia (APL) presumably by binding directly to RAR alpha of APL cells. Leukemic blasts from APL patients initially responsive to RA can become resistant to the agent. HL-60 myeloblasts cultured with RA have developed mutations of the ligand-binding region of RAR alpha and have become resistant to RA. Furthermore, insertion of an RAR alpha with an alteration in the ligand-binding region into normal murine bone marrow cells can result in growth factor-dependent immortalization of the early hematopoietic cells. To determine if alterations of the ligand binding domain of RAR alpha might be involved in several malignant hematologic disorders, the mutational status of this region (exons 7, 8, and 9) was examined in 118 samples that included a variety of cell lines and fresh cells from patients with myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML), including 20 APL patients, 5 of whom were resistant to RA and 1 who was refractory to RA at diagnosis, using polymerase chain reaction-single- strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. In addition, 7 of the 20 APLs were studied for alterations of the other coding exons of the gene (exons 2 through 6). No mutations of RAR alpha were detected. Although the sensitivity of PCR-SSCP analysis is less than 100%, these findings suggest that alterations of RAR alpha gene are rare and therefore other mechanisms must be involved in the onset of resistance to retinoids and in the lack of differentiation in disorders of the myeloid lineage.     

Evaluation of E-rosetting human lymphocytes with OKT11 and other monoclonal antibodies

Monoclonal antibody OKT11 was found to compete with sheep red blood cells for binding sites on human lymphocytes. Preincubation of lymphocytes with OKT11 eliminated E-rosette formation. In a study of 142 peripheral blood samples ranging from 1% to over 90% E-rosette- positive cells, comparison to the percent OKT11-positive cells yielded a correlation coefficient of 0.93. In normal donors, subsets of OKT11+ cells were identified using two-color immunofluorescent staining methods with OKT3, OKT4, and OKT8. On the average, approximately 13% of OKT11+ lymphocytes were OKT3- and 13% of OKT11+ lymphocytes were OKT4- and OKT8-. Based on our double antibody fluorescence intensity data, low antigen density OKT11+ lymphocytes were OKT3-. OKT4+ and OKT8+ lymphocytes in normal peripheral lymphocytes have similar OKT11 antigen density.     

Adverse effects of extra-articular corticosteroid injections: a systematic review

Background  

To estimate the occurrence and type of adverse effects after application of an extra-articular (soft tissue) corticosteroid injection.     

The search for stable prognostic models in multiple imputed data sets

Background  

In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B) and Multiple imputation (MI). The authors examined the influence of these methods on model composition.     

The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: A clarification of its content

Background  

The COSMIN checklist (COnsensus-based Standards for the selection of health status Measurement INstruments) was developed in an international Delphi study to evaluate the methodological quality of studies on measurement properties of health-related patient reported outcomes (HR-PROs). In this paper, we explain our choices for the design requirements and preferred statistical methods for which no evidence is available in the literature or on which the Delphi panel members had substantial discussion.     

Health care services utilization stratified by virological and immunological markers of HIV: evidence from a universal health care setting

Objective

The aim of the study was to determine rates of utilization of in‐patient, out‐patient and laboratory services stratified by virological and immunological markers of HIV disease among patients on antiretroviral treatment in British Columbia, Canada.

Methods

We estimated resource utilization for in‐patient visits, out‐patient visits, and laboratory tests among patients initiating antiretroviral treatment between 1 April 1994 and 31 December 2000, with follow‐up to 31 March 2001. Resource use was stratified by CD4 cell count and plasma HIV viral load (pVL) at the time of utilization and rates per 100 patient‐years were calculated for each health care resource.

Results

A total of 2718 patients were included in our analyses. The overall rates of in‐patient visits, out‐patient visits, and laboratory tests were 902, 3001 and 840 per 100 patient‐years, respectively. Utilization was higher for patients with low CD4 cell counts and high pVLs when compared with patients with high CD4 cell counts and low pVLs.

Conclusions

Patients with low CD4 cell counts and high pVLs had the highest use of health care services. Regular follow‐up with health care providers in an out‐patient setting, allowing for proper monitoring and maintenance of HIV care, is important in minimizing unnecessary and potentially costly in‐patient care.