Functional role for Syk tyrosine kinase in natural killer cell-mediated natural cytotoxicity.

Natural killer (NK) cells are named based on their natural cytotoxic activity against a variety of target cells. However, the mechanisms by which sensitive targets activate killing have been difficult to study due to the lack of a prototypic NK cell triggering receptor. Pharmacologic evidence has implicated protein tyrosine kinases (PTKs) in natural killing; however, Lck-deficient, Fyn-deficient, and ZAP-70-deficient mice do not exhibit defects in natural killing despite demonstrable defects in T cell function.

Refractory hypoxemia due to intrapulmonary shunting associated with bronchioloalveolar carcinoma.

Bronchioloalveolar carcinoma caused severe refractory hypoxemia due to intrapulmonary shunting in a patient. Preoperative evaluation by occlusion of the pulmonary lobar artery supplying the tumor showed normalization of the arterial oxygen saturation. Resection of the involved lobe corrected the intrapulmonary shunting, and the patient required no further supplemental oxygen.

O2-induced change in ventilation and ventilatory drive in COPD.

We examined the role of respiratory control during O2-induced hypercarbia in patients with chronic obstructive pulmonary disease (COPD), by comparing the observed change in ventilation (delta VEobs) with the delta VE predicted (delta VEpred) from the patients' ventilatory drive and the O2-induced delta PaCO2 and delta SaO2. Eleven stable hypoxemic COPD patients (mean +/- SD: FEV1 = 1.00 +/- 0.

Sequential involvement of Lck and SHP-1 with MHC-recognizing receptors on NK cells inhibits FcR-initiated tyrosine kinase activation.

Recognition of major histocompatibility (MHC) class I complexes on target cells by killer cell inhibitory receptors (KIR) blocks natural killer (NK) and T cell cytotoxic function. The inhibitory effect of KIR ligation requires the phosphotyrosine-dependent association of KIR with the cytoplasmic SH2-containing protein tyrosine phosphatase SHP-1. Using a somatic genetic model, we first define a requirement for the Src family protein tyrosine kinase (PTK) Lck in mediating KIR tyrosine phosphorylation.

Clonotypic differences in signaling from CD94 (kp43) on NK cells lead to divergent cellular responses.

Ligation of MHC class I-recognizing receptors on NK cells dramatically modulates their secretory and cytotoxic function. This study focuses on characterizing key signaling events regulating these activities after ligation of the C-type lectin superfamily member, CD94. We isolated separate clonal populations of human NK cells in which ligation of CD94 (kp43) either triggered cell-mediated cytotoxicity (group A clones) or potently inhibited NK cell activation (group B clones).

Patient-ventilator interactions.

Patient-ventilator synchrony is important in the management of the ventilator-dependent patient. Factors inherent to the patient and the ventilator influence patient-ventilator synchrony. Detection of patient-ventilator synchrony may require monitoring of airway pressure and flow waveforms.

Investigation of applicability of alanine and radiochromic detectors to dosimetry of proton clinical beams.

Cancer therapy studies using proton accelerators are underway in several major medical centers in the U.S., Russia, Japan and elsewhere.

False-positive I-131 images mimicking thyroid cancer metastasis. The nose ring sign.

This case report describes an I-131 whole-body scan with false-positive uptake at the site of a nose ring in a patient with follicular thyroid cancer.

Interaction between lck and syk family tyrosine kinases in Fc gamma receptor-initiated activation of natural killer cells.

Ligation of the Fc gamma R on natural killer (NK) cells results in the tyrosine phosphorylation of multiple substrates critical for intracellular signaling and activation of NK cell effector functions. However, it remains unclear which nonreceptor protein-tyrosine kinases (PTK) participate in this process. In this report we demonstrate that Fc gamma R ligation induced the tyrosine phosphorylation and increased the catalytic activities of both syk family PTKs, ZAP-70, and syk.

Alkalosis and hypomagnesaemia: unwanted effects of a low-calcium CAPD solution.

We studied 43 CAPD patients for 4 months during the change from a high-calcium dialysis fluid (Baxter PD1) to a low-calcium fluid (Baxter PD4), which also contained low magnesium (0.25 mmol/l) and high lactate concentrations (40 mmol/l). Serum calcium fell significantly as did the incidence of hypercalcaemia, whilst the proportion of patients taking calcium-containing phosphate binders increased.

Tyrosine kinase activation provides an early and requisite signal for Fas-induced apoptosis.

Selective cell death plays a critical role in the development of the immune repertoire and in the elimination of target cells expressing foreign Ags. The apoptosis induced by ligation of the Fas Ag, a member of the TNFR/nerve growth factor receptor superfamily, contributes to both of these modes of cell loss. However, in spite of the molecular cloning of the Fas Ag and the identification of a specific cytoplasmic domain required for its function, it remains unclear as to which Fas-induced second messengers mediate the development of programmed cell death.

Emergency department two-dimensional echocardiography in the diagnosis of nontraumatic cardiac rupture.

Myocardial rupture is a catastrophic complication of acute myocardial infarction that usually results in sudden death. If diagnosed quickly, patients with myocardial rupture may be salvaged. This report describes the application of emergency department two-dimensional echocardiography in the diagnosis of six cases of myocardial rupture over two years.

Epidemiology of psychiatric disorders in Edmonton. Panic disorder.

A random sample of 3258 adult household residents of Edmonton, Alberta, Canada were interviewed by trained lay interviewers using the Diagnostic Interview Schedule (DIS), which gives DSM-III diagnostic data on each individual interviewed. This paper reports results for panic disorder. Panic disorder was found to affect women primarily (female:male morbidity risk 2.

Epidemiology of psychiatric disorders in Edmonton. Phobic disorders.

3258 randomly selected adult household residents of the city of Edmonton were interviewed by trained lay interviewers using the Diagnostic Interview Schedule (DIS). Using DMS-III criteria, hierarchy-free, the lifetime prevalence for all phobias was 8.9%.

Differentiating systolic from diastolic heart failure: pathophysiologic and therapeutic considerations.

Purpose: To compare and contrast the pathophysiology and therapy of heart failure with normal and abnormal systolic ventricular function.

Methods: Review of basic pathophysiologic mechanisms, clinical data, and therapeutic trials.

Conclusions: The clinical features of heart failure may be similar regardless of whether ventricular function is normal or abnormal.

A radiation accident at an industrial accelerator facility.

On 11 December 1991, a radiation overexposure occurred at an industrial radiation facility in Maryland. The radiation source was a 3-MV potential drop accelerator designed to produce high electron beam currents for materials-processing applications. This accelerator is capable of producing a 25 milliampere swept electron beam that is scanned over a width of 112.

Image information transfer properties of x-ray intensifying screens in the energy range from 17 to 320 keV.

The image information transfer properties of a number of x-ray fluorescent screens have been measured for x-ray energies from 17 to 320 keV. The detective quantum efficiency of the screens at each x-ray energy has been determined by separate measurements of the x-ray absorption efficiency and the statistical factor associated with the emission of optical photons upon absorption of an incident x-ray. Data have been recorded for both rare-earth phosphor screens and calcium tungstate screens.

Echocardiography in the evaluation of cardiac sources of emboli: the role of transthoracic echocardiography.

Cardioembolism is responsible for a significant number of systemic emboli including approximately 15% of all ischemic strokes. Transthoracic echocardiography has contributed to the understanding of cardioembolism and has been used to detect specific and potential cardiac sources of systemic emboli and risk stratify patients with specific clinical findings for subsequent cardiovascular events. Findings from transthoracic echocardiography indicate that stasis is an important prerequisite for intracardiac thrombosis while reversal of stasis and thrombolysis appear operative in embolism of existing thrombus.

Interleukin-2 signal transduction in human NK cells: multisite phosphorylation and activation of the tyrosine kinase p56lck.

Interleukin-2 (IL-2) potently stimulates natural killer (NK) cell proliferation and cytotoxic function. However, the molecular mechanisms by which IL-2 delivers activation signals from the IL-2 receptor to the NK cell interior are incompletely understood. Previous studies demonstrated that IL-2 stimulation induced the tyrosine phosphorylation of multiple proteins in NK cells, together with a prominent reduction in the electrophoretic mobility of p56lck.

Relationship between stress protein induction in rat kidney by mercuric chloride and nephrotoxicity.

Adverse environmental stimuli increase the synthesis of a class of proteins referred to as stress proteins. The effect of mercuric chloride, a model nephrotoxin, on protein synthesis in male rat kidney has been evaluated. Renal slices from exposed rats were incubated with [35S]methionine for 1 hr and subjected to SDS-PAGE, after which 35S-labeled proteins were detected by autoradiography.

Frequent occurrence of occult pulmonary embolism from venous sheaths during endomyocardial biopsy.

To determine the frequency of occult right heart thromboembolism during endomyocardial biopsy, 51 cardiac transplant recipients undergoing routine endomyocardial biopsy were studied echocardiographically. Patients were randomized to two groups. In Group 1, the venous sheath was flushed between each biopsy attempt; in Group 2, it was flushed only at the time of initial placement.

Phylogenetic relationships among megabats, microbats, and primates.

We present 744 nucleotide base positions from the mitochondrial 12S rRNA gene and 236 base positions from the mitochondrial cytochrome oxidase subunit I gene for a microbat, Brachyphylla cavernarum, and a megabat, Pteropus capestratus, in phylogenetic analyses with homologous DNA sequences from Homo sapiens, Mus musculus (house mouse), and Gallus gallus (chicken). We use information on evolutionary rate differences for different types of sequence change to establish phylogenetic character weights, and we consider alternative rRNA alignment strategies in finding that this mtDNA data set clearly supports bat monophyly. This result is found despite variations in outgroup used, gap coding scheme, and order of input for DNA sequences in multiple alignment bouts.

Use of storage phosphor imaging plates in portal imaging and high-energy radiography: the intensifying effect of metallic screens on the sensitivity.

The sensitivity of storage phosphor imaging plates (SPIP) at megavolt photon energies (60Co, 6-, 10-, and 18-MV radiotherapy beams) is studied both experimentally and by Monte Carlo radiation transport calculations. In addition, the same techniques are used to investigate the intensifying effect of metal screens on the sensitivity of the SPIP. The results provide evidence that the sensitivity of the SPIPs is proportional to the absorbed energy in the phosphor layer per cGy.