Association of CD2 and T200 (CD45) in mouse T lymphocytes

A monoclonal antibody (mAb 12-15) reactive with the mouse CD2 was found to co-precipitate a high-molecular-weight glycoprotein from mouse thymocyte, splenic lymphocyte, Con A blast, and T cell tumor detergent lysates which was identified as the leukocyte common T 200 glycoprotein (CD45). The reactivity was specific for CD2 since antibodies to CD3 did not co-precipitate the T200 glycoprotein. mAb 12-15 did not react with immunoaffinity-purified T200 glycoprotein, ruling out the possibility that the antibody detected a cross-reactive epitope. Biochemical data indicated that the association of CD2 with T200 was not generated during lysis of the cell and that the molecular complex was non-covalently linked since it could be destroyed by high salt washing or boiling in SDS. Distribution analysis in Triton X114-H2O revealed that, in contrast to free T200 molecules, the complexed T200 was enriched in the detergents phase. To investigate the CD2-T200 association in more detail at the cell surface, modulation of CD2 and T200 was studied. Modulation could be induced on Con A blasts by monoclonal antibodies followed by cross-linking with a FITC-conjugated second antibody. Within 24 h the expression of CD2 or T200 was reduced to approximately 10-20% of the initial value on the majority of cells. However, two-color fluorescence showed that modulation of CD2 did not lead to co-modulation of CD3 or T200. A possible physiological role of CD2-T200 complexes is discussed.     

Environmental study of firefighters.

A study of firefighter exposures was undertaken at the request of the U.S. Fire Administration. This work was part of a larger study which included field evaluation of the performance of the self-contained breathing apparatus (SCBA) worn by firefighters during structural firefighting. Measurements were made for a variety of contaminants including CO, CO2, benzene, HCN, HCl, H2SO4, HF, acrolein, CH4, formaldehyde and PNAs. Many of the analyses were performed by collection of bag samples followed by Fourier transform infrared spectroscopy using a field mobile spectrometer. Measurements were also made using solid sorbent tubes and direct-reading meters. Sampling was done both during the knockdown and during overhaul phases of structural firefighting. Also, in order to estimate exposures including those when the SCBAs were worn, measurements were made both inside and outside the SCBA facepiece. Carbon monoxide was the most common contaminant found during knockdown, and about 10% of the samples were greater than 1500 ppm. Formaldehyde, acrolein, hydrogen chloride, hydrogen cyanide, sulphuric acid and hydrogen fluoride all exceeded their respective short-term exposure limits (STEL) on some occasions. Approximately 50% of the knockdown samples for acrolein exceeded the STEL. During overhaul, when masks were usually not worn, many of the contaminants found during knockdown were detected, but typically at much lower concentrations. Inside-mask sampling data suggest that exposure to low concentrations of a variety of compounds is occurring but this is believed to be principally the result of early mask removal or of non-use during knockdown rather than of leakage. The three basic sampling approaches (bag sampling, sorbent tubes and direct-reading meters) proved in this study to be complementary and served to maximize our ability to detect and quantify a wide range of combustion products.     

Effects of peer-group intervention on metabolic control of adolescents with IDDM. Randomized outpatient study

In children with insulin-dependent diabetes mellitus (IDDM), deterioration in metabolic control frequently occurs during early adolescence. To prevent this predictable increase in blood glucose levels, we randomly assigned young adolescents with IDDM to an intervention based on problem solving with self-monitoring of blood glucose (SMBG) integrated into standard outpatient care or to standard care only for an 18-mo period. At follow-up, 50% of the standard-care adolescents exhibited greater than 1% increase in glycosylated hemoglobin (HbA1) levels over baseline values, indicating a deterioration in metabolic control, compared to only 23% of the intervention group. Follow-up HbA1 means +/- SD were 10.10 +/- 2.00% for intervention and 11.04 +/- 2.28% for standard-care adolescents, indicating a significantly lower value in the intervention group (P = .04). At follow-up, a greater percentage of intervention than standard-care adolescents reported using SMBG information when they exercised (60.0 vs. 33.3%, chi 2 = 4.29, P = .04). Our data suggest that clinic-based problem-solving groups can be more effective with young adolescents with IDDM than conventional treatment in preventing the expected deterioration in blood glucose.     

Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood-derived platelets and apheresis platelets

BACKGROUND: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system. STUDY DESIGN AND METHODS: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux). RESULTS: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture. CONCLUSION: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.     

Bilaterale Instabilität – „perils and pitfalls“ der operativen Stabilisierung

Background

Instabilities of the elbow joint can occur acutely in the context of elbow dislocation as well as chronically after inadequate healing of an atraumatic ligament tear or due to repetitive microtraumas, especially in athletes who throw. Difficulties often arise with regard to care and treatment both in the acute situation and in chronic cases. Preoperatively, it is important to assess the unilateral or bilateral extent of injury.

Methods

Comparative review using PubMed. Inductive reasoning.

Results

There are many reasons for elbow instability; however, an objective diagnostic workup is not yet established. Nevertheless, the anamnesis can be used to detect instability and to adjust the therapeutic steps by means of a targeted clinical and imaging diagnostic workup. Decisive criteria in the surgical treatment of instabilities are the duration of trauma or alternatively in case of nontraumatic complaints the onset of symptoms and the extent of the injury (unilateral or bilateral) itself.

Conclusion

Decisive in the treatment of acute traumatic injuries is the correct detection of the prevailing instability and the observation of the therapeutic time window for the refixation of the lateral ligament complexes. In case of chronic instability, surgery may have to be recommended after examination and consideration of the professional and leisure time requirements. The surgical procedure is of crucial importance, especially in case of bilateral instability. In principle, biomechanical requirements are met and secondary degenerative sequelae should be avoided if possible.

     

Measuring the domain completeness of the Nursing Interventions Classification in parish nurse documentation

As the healthcare industry moves toward automating the patient record, care providers have been challenged to capture their domain of practice in a computerized format. Nurses have responded by developing a number of American Nurses Association (ANA) recognized nursing standardized terminologies. This study measured the domain completeness and uses of one such terminology, the Nursing Interventions Classification (NIC), within the specialty of parish nursing, a spiritually focused, community-based practice. Documentation samples from 170 health records submitted by 13 parish nurses in 7 sites across the country, stratified by urban, suburban, and rural sites were used. The nursing interventions that were documented in 1607 unique interactions in these charts were mapped into NIC using standardized mapping procedures. Intercoder reliability was assessed, with a final kappa of 0.92 (93% agreement) and code-recode reliability with a kappa of 0.72 (74% agreement). Overall, 93% of the 3059 interventions mapped into NIC. Recommended modifications in existing NIC labels and additional NIC labels are presented. The results suggest that NIC supports the documentation of parish nursing practice and has the capability of capturing the spiritual dimension of care.     

Non-T cell activation linker (NTAL): a transmembrane adaptor protein involved in immunoreceptor signaling

A key molecule necessary for activation of T lymphocytes through their antigen-specific T cell receptor (TCR) is the transmembrane adaptor protein LAT (linker for activation of T cells). Upon TCR engagement, LAT becomes rapidly tyrosine phosphorylated and then serves as a scaffold organizing a multicomponent complex that is indispensable for induction of further downstream steps of the signaling cascade. Here we describe the identification and preliminary characterization of a novel transmembrane adaptor protein that is structurally and evolutionarily related to LAT and is expressed in B lymphocytes, natural killer (NK) cells, monocytes, and mast cells but not in resting T lymphocytes. This novel transmembrane adaptor protein, termed NTAL (non-T cell activation linker) is the product of a previously identified WBSCR5 gene of so far unknown function. NTAL becomes rapidly tyrosine-phosphorylated upon cross-linking of the B cell receptor (BCR) or of high-affinity Fcgamma- and Fc epsilon -receptors of myeloid cells and then associates with the cytoplasmic signaling molecules Grb2, Sos1, Gab1, and c-Cbl. NTAL expressed in the LAT-deficient T cell line J.CaM2.5 becomes tyrosine phosphorylated and rescues activation of Erk1/2 and minimal transient elevation of cytoplasmic calcium level upon TCR/CD3 cross-linking. Thus, NTAL appears to be a structural and possibly also functional homologue of LAT in non-T cells.     

Bridging Self-Reinforcing Double-Row Rotator Cuff Repair: We Really Are Doing Better

Single-row versus double-row repair of rotator cuff tears is currently a controversial topic. In this Level V article, we articulate why we believe that second-generation double-row repair techniques, which use bridging sutures to link the 2 rows of suture anchors together in a self-reinforcing manner, are producing superior clinical and biomechanical results.