Plasma P-selectin is increased in thrombotic consumptive platelet disorders

P-selectin is a 140-kD protein found in the alpha-granules of platelets and the Weibel-Palade bodies of endothelial cells that on cell activation is expressed on the cell surface and also secreted into the plasma. The secreted form of P-selectin, like plasma P-selectin, differed from platelet membrane P-selectin in that its molecular mass was approximately 3 kD lower under reducing conditions. Both the secreted and plasma forms of P-selectin contained cytoplasmic sequence as determined by Western blot analysis with an affinity-purified rabbit anti-P-selectin cytoplasmic peptide antibody. We have measured plasma P- selectin and beta-thromboglobulin (beta TG) concurrently in (1) patients with consumptive thrombotic disorders, including disseminated intravascular coagulation (DIC), heparin-induced thrombocytopenia (HIT), and thrombotic thrombocytopenic purpura (TTP)/haemolytic uremic syndrome (HUS); (2) patients with idiopathic thrombocytopenic purpura (ITP); and (3) healthy controls. Patients with DIC, HIT, and TTP/HUS, but not ITP, had significantly elevated plasma P-selectin and beta TG levels when compared with their age-matched healthy controls. The increased plasma P-selectin and beta TG in patients with thrombotic disorders were likely to be the result of in vivo platelet and endothelial cell damage or activation. We also found that avoidance of veno-occlusion and other tedious measures customarily taken during blood collection and sample preparation to prevent in vitro platelet activation did not affect plasma P-selectin assay results. In addition, plasma P-selectin levels were not influenced by the presence of renal failure or heparin administration. These results indicate that plasma P- selectin may be a useful new marker for thrombotic diseases.     

An endogenous glycosylphosphatidylinositol-specific phospholipase D releases basic fibroblast growth factor-heparan sulfate proteoglycan complexes from human bone marrow cultures

Basic fibroblast growth factor (bFGF) is a hematopoietic cytokine that stimulates stromal and stem cell growth. It binds to a glycosylphosphatidylinositol (GPI)-anchored heparan sulfate proteoglycan on human bone marrow (BM) stromal cells. The bFGF- proteoglycan complex is biologically active and is released by addition of exogenous phosphatidylinositol-specific phospholipase C. In this study, we show the presence of an endogenous GPI-specific phospholipase D (GPI-PLD) that releases the bFGF-binding heparan sulfate proteoglycan and the variant surface glycoprotein (a model GPI-anchored protein) from BM cultures. An involvement of proteases in this process is unlikely, because released proteoglycan contained the GPI anchor component, ethanol-amine, and protease inhibitors did not diminish the release. The mechanism of release is likely to involve a GPI-PLD and not a GPI-specific phospholipase C, because the release of variant surface glycoprotein did not reveal an epitope called the cross- reacting determinant that is exposed by phospholipase C-catalyzed GPI anchor cleavage. In addition, phosphatidic acid (which is specifically a product of GPI-PLD-catalyzed anchor cleavage) was generated during the spontaneous release of the GPI-anchored variant surface glycoprotein. We also detected GPI-PLD-specific enzyme activity and mRNA in BM cells. Therefore, we conclude that an endogenous GPI-PLD releases bFGF-heparan sulfate proteoglycan complexes from human BM cultures. This mechanism of GPI anchor cleavage could be relevant for mobilizing biologically active bFGF in BM. An endogenous GPI-PLD could also release other GPI-anchored proteins important for hematopoiesis and other physiologic processes.     

Epinephrine-induced alterations in urinary cyclic AMP in hyper- and hypothyroidism.

Although ratios of urinary cyclic AMP (cAMP) to creatinine were found in this study to be elevated in hyperthyroidism, as previously reported, this elevation appears to result primarily from a decrease in the rate of urinary creatinine excretion associated with the hyperthyroid state and not to be due to an increase in the urinary cAMP production rate. Indeed, there was no significant alteration observed in the urinary cAMP excretion found in 15 hyper-, 12 eu-, and 5 hypothyroid subjects. However, a slight, but significant increase in the 24-hour urinary cAMP excretion was noted in ambulating hyperthyroid subjects (8.5 +/- 2.4 muMol/day; normal 5.2 +/- 1.6 muMol/day; P less than .05). In contrast, the effect of the infusion of 0.05 mug/kg/min of epinephrine over a 2-hour period, resulted in a significantly greater rise in urinary cAMP excretion in hyperthyroid patients (0.83 +/- 0.07 muMol/h) compared to euthyroid subjects (0.53 +/- 0.4 muMol/h; P less than .005). Furthermore, hypothyroid subjects had no significant rise in urinary cAMP excretion after epinephrine infusion (P less than .001). Cardiovascular end-organ response to the epinephrine infusion was also greater in the hyperthyroid subjects and virtually absent in the hypothyroid group. These results suggest that there may be a significant alteration in the cAMP generating systems in states of thyroid hormone excess or insufficiency, and that provocative stimuli, such as epinephrine, may have its end-organ response modified by thyroid hormone effects on adenylate cyclase-cyclic AMP generating systems.     

In vitro pleural fluid clottability and fibrinogen content.

Twenty-three specimens of pleural fluid from 23 patients were examined for quantitative fibrinogen, total protein levels, and for clottability in vitro using the recalcification time. Of the 19 specimens of pleural fluid from patients without loculation, 11 (seven exudates) had no detectable fibrinogen; another 8 (six exudates) had a mean fibrinogen level of 55.0 +/- 10.2 mg percent, and a mean recalcification time of 19.4 +/- 2.6 minutes. The pleural fluids from the four patients with loculation had no detectable fibrinogen. The only fluids containing fibrinolytic activity were from the nonloculated non-fibrinogen-containing group. No correlation existed between pleural fluid/plasma total protein ratios and pleural fluid/plasma fibrinogen ratios. In vitro clottability in this study did not reflect the in vivo tendency for coagulation and loculation.     

The management of stage I--II Hodgkin's disease with irradiation alone or combined modality therapy: the Stanford experience

At Stanford University, between 1968 and 1978, 230 patients with pathologic stage I--II Hodgkin's disease were treated on prospective clinical trials with either irradiation alone or irradiation followed by 6 cycles of adjuvant combination chemotherapy. The actuarial survival at 10 yr was 84% for patients in either treatment group. Freedom from relapse at 10 yr was 77% among patients treated with irradiation alone and 84% after treatment with combined modality therapy [p(Gehan) = 0.09]. Freedom from second relapse at 10 yr was 89% and 94%, respectively [p(Gehan) = 0.56]. Several prognostic factors were evaluated in order to identify patients at high risk for relapse or with poor ultimate survival after initial treatment with irradiation alone. Systemic symptoms, histologic subtype, age, and limited extranodal involvement (E-lesions) did not affect the prognosis of patients and failed to identify patients whose survival could be improved by the routine use of combined modality therapy. Patients with large mediastinal masses (mediastinal mass ratio greater than or equal to 1/3) had a significantly poorer freedom from relapse when treated with irradiation alone than when treated initially with combined modality therapy [45% versus 81% at 10 yr, p(Gehan) = 0.03). The 10-yr survival of these patients, however, was not significantly different (84% versus 74%). The implications of these observations on the management of patient with early stage Hodgkin's disease are discussed.     

Association between sensitisation and pain-related behaviours in an experimental canine model of osteoarthritis

Evaluation of nociceptive sensitisation in canine osteoarthritis studies has been poorly reported, or even related to other clinical symptoms. In 16 dogs, peak vertical force (PVF), subjective pain assessment using 3 scales, sympathetic stress response with electrodermal activity (EDA) measurement, and behavioural changes with video analysis and telemetered motor activity were quantified at baseline (D-7), and 28 and 56 days post transection of the cranial cruciate ligament. As markers of central sensitisation, selected spinal cord biomarkers (substance P and transthyretin) were quantified at D56. Electrical withdrawal thresholds on the stifle and the tail were measured as indicative of peripheral and central quantitative sensory testing (QST) sensitisation, respectively. The effects of vehicle administration (n = 8) were compared with tiludronate (2 mg/kg subcutaneously, q2week, starting at D0) administration. Generalized estimated equations tested the association between the behavioural and physiological methods and QST sensitisation, and therefore the sensitivity of the methods for detecting treatment efficacy. Compared to tiludronate, at D56, vehicle-treated dogs had increased spinal substance P (P = 0.01), concomitant decreased transthyretin (P = 0.02), and (compared to baseline) demonstrated peripheral and central QST sensitisation, which was not present for tiludronate. Only PVF, the spontaneous behaviour “walking with full weight-bearing,” and EDA were associated with occurrence of QST sensitisation and indicated significant tiludronate analgesic efficacy after inclusion of central QST sensitisation as a predictor variable in the statistical model. This study establishes the strong interest to implement QST as a predictor of canine osteoarthritis pain symptoms explained by pain sensitisation.     

A Randomized Controlled Pilot Study of a Cognitive-Behavioral Therapy Approach for Painful Diabetic Peripheral Neuropathy

The purpose of the present pilot study was to assess the efficacy of cognitive-behavioral therapy (CBT) for painful diabetic peripheral neuropathy. This was a randomized, treatment as usual (TAU), controlled, nonblinded intervention pilot study with a 4-month follow-up conducted in a VA medical center. It was hypothesized that participants who received CBT, as compared to those who received TAU, would report significant decreases on self-report measures of pain severity, interference, and depressive symptoms from pretreatment to 4-month follow-up. Participants meeting inclusion criteria were randomly assigned to 1 of the study conditions. Of the 20 eligible participants, 12 were randomized to CBT and 8 were randomized to TAU. Participants randomized to CBT showed significant decreases on measures of pain severity (B = ?.54) and pain interference (B = ?.77) from pretreatment to 4-month follow-up. There were no significant changes in the TAU participants' scores on measures of pain severity (B = .00) or pain interference (B = ?.09). Neither CBT nor TAU participants showed significant changes in their levels of depressive symptoms from pretreatment to 4-month follow-up. CBT may be an effective treatment approach for reducing pain severity and interference associated with painful diabetic peripheral neuropathy.PerspectiveThe results of this study suggest that engaging patients in CBT for painful diabetic peripheral neuropathy may provide them the skills to become more active and experience less pain.     

The effect of external load on torque production by knee extensors

The kinematics of the knee joint are load-dependent; the length of the lever arm of the extensor mechanism and the pathway of the instant center of rotation vary with external load. This study was conducted to determine if the maximum extensor torque-generating capacity of the knee joint is dependent on the distance from the knee joint at which the external force resisting extension is located. Maximum isometric extensor torques were measured at 90 and 30 degrees of knee flexion while the distance from the knee joint to the resisting force was varied. Our results demonstrated that the subjects generated larger maximum extensor torques, at both 90 and 30 degrees of knee flexion, when the external resisting force was positioned farther distal to the knee joint. This increase was as large as 50 per cent with the knee at 30 degrees of flexion.     

Measurement of Anterior and Posterior Circulation Flow Contributions to Cerebral Blood Flow

Ultrasound-derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the antenor (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (Internal carotid arteries bilaterally) carried 82% of the brain's blood supply and compnsed 67% of the total vascular cross-sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen-Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound-derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.     

The Predictors of Parental Use of Corporal Punishment

Abstract: Corporal punishment has been the focus of considerable study over the past decade. Some recent research suggesting that the use of corporal punishment may have significant long‐term negative effects on children has prompted increasing exploration and interest in the issue. We used tobit regression analysis and data from the 2000 National Longitudinal Survey of Youth to examine both the prevalence and the chronicity of spanking in a nationally representative sample of parents. Mother’s characteristics (e.g., age, education) and neighborhood context did not show a relationship with parental use of corporal punishment. Among parents who used corporal punishment, being Protestant had a relatively large relationship with its use. Although children’s externalizing behaviors had some association with parent’s propensity to spank, findings suggest that use of corporal punishment may be better understood as part of a constellation of behaviors relating to a parenting style. Further, findings indicate that it is easier to predict the incidence of corporal punishment than to predict its frequency of use.