Dynamic platelet function on von Willebrand factor is different in preterm neonates and full-term neonates: changes in neonatal platelet function.

Essentials It is unclear if platelet function differs between preterm and full-term neonates. Platelet behavior was characterized using a flow-based assay on von Willebrand Factor (VWF). Preterms had increased platelet interaction with VWF and glycoprotein Ibα expression. Platelets from preterm neonates behave differently on VWF compared to full-term neonates. SUMMARY: Background Very low birth weight (VLBW) preterm neonates have an increased risk of hemorrhage-related morbidity and mortality as compared with their full-term counterparts. It is unclear whether platelet function differs between preterm and full-term neonates. This is partly because of the large volumes of blood required to perform standard platelet function tests, and the difficulty in obtaining such samples in neonates. Objectives This study was designed to characterize platelet behavior in neonates with a physiologic flow-based assay that quantifies platelet function in microliter volumes of blood under arterial shear. Methods Blood from VLBW preterm neonates of ≤ 32 weeks' gestation (n = 15) and full-term neonates (n = 13) was perfused under arterial shear over surface-immobilized von Willebrand factor (VWF). Platelet behavior was recorded by digital-image microscopy and analyzed. Surface expression of platelet glycoprotein (GP) Ibα and GPIIIa of VLBW preterm and full-term neonates was also measured. Results VLBW preterm neonates had increased numbers of platelets interacting with VWF, and increased GPIbα expression on the platelet surface. Despite the increased numbers of VWF interactions as reflected by flow-driven platelet translocation along the protein surface, no significant differences were observed in the numbers of platelets that adhered in a stationary fashion to VWF. Platelets from VLBW preterm neonates and those from full-term neonates behaved differently on VWF. Conclusions These differences in platelet function may contribute to the higher incidence of bleeding observed in VLBW preterm neonatal populations, or may represent a compensatory mechanism to counteract this risk of bleeding.

Prevalence of housing needs among inpatients: a 1 year audit of housing needs in the acute mental health unit in Tallaght Hospital.

OBJECTIVE: There is a dearth of information relating to the prevalence of housing needs among psychiatric in-patients in Ireland. Most of the information we have to date emerged as a result of attempts to plan for the closure of old psychiatric hospitals and inappropriate community residences. This study sought to identify the prevalence of housing needs among in-patients in the acute psychiatric unit in Tallaght Hospital. METHODS: Each week, over a 12-month period, nursing managers and/or key nurses who knew the patients well were asked for numerical data. Information was collected on the numbers of in-patients with accommodation needs, number of delayed discharges due to accommodation needs and number of discharges to homeless accommodation in the previous week. RESULTS: On average, 38% of in-patients had accommodation related needs at any one time. Most (98%) of delayed discharges had accommodation related needs. Delayed discharge in-patients with accommodation needs accounted for 28% of all inpatients and for 72% of all inpatients with accommodation related needs. CONCLUSIONS: Accommodation need among psychiatric in-patients is underreported. Housing need data should be routinely collected and effective interagency strategies developed to address housing needs.

The role of Nox1 and Nox2 in GPVI-dependent platelet activation and thrombus formation.

BACKGROUND: Activation of the platelet-specific collagen receptor, glycoprotein (GP) VI, induces intracellular reactive oxygen species (ROS) production; however the relevance of ROS to GPVI-mediated platelet responses remains unclear. OBJECTIVE: The objective of this study was to explore the role of the ROS-producing NADPH oxidase (Nox)1 and 2 complexes in GPVI-dependent platelet activation and collagen-induced thrombus formation. METHODS AND RESULTS: ROS production was measured by quantitating changes in the oxidation-sensitive dye, H2DCF-DA, following platelet activation with the GPVI-specific agonist, collagen related peptide (CRP). Using a pharmacological inhibitor specific for Nox1, 2-acetylphenothiazine (ML171), and Nox2 deficient mice, we show that Nox1 is the key Nox homolog regulating GPVI-dependent ROS production. Nox1, but not Nox2, was essential for CRP-dependent thromboxane (Tx)A2 production, which was mediated in part through p38 MAPK signaling; while neither Nox1 nor Nox2 was significantly involved in regulating CRP-induced platelet aggregation/integrin αIIbß3 activation, platelet spreading, or dense granule and α-granule release (ATP release and P-selectin surface expression, respectively). Ex-vivo perfusion analysis of mouse whole blood revealed that both Nox1 and Nox2 were involved in collagen-mediated thrombus formation at arterial shear. CONCLUSION: Together these results demonstrate a novel role for Nox1 in regulating GPVI-induced ROS production, which is essential for optimal p38 activation and subsequent TxA2 production, providing an explanation for reduced thrombus formation following Nox1 inhibition.

Low dose intraarterial thrombolysis with tissue plasminogen activator: does it deliver as promised?

The widespread use of intraarterial thrombolytic therapy has been based on perceived benefits over operative treatment and the downgrading of the magnitude of subsequent surgery. Thirty-three patients who had thrombolysis for peripheral artery occlusion were retrospectively analyzed at St. James's Hospital from 1991 to 1997. One patient received streptokinase unsuccessfully. Five other patient's records were inadequate for analysis. Twenty-seven patient's notes were analyzed for risk, duration of occlusion, duration of treatment, dosage of tissue plasminogen activator (tPA) and conduits thrombolysed. There were 15 males and 12 females. The mean age was 62 years (range, 20-87). Fourteen were current or reformed smokers. Five were diabetic. Indications for treatment included acute graft occlusion (n=13), embolus (n=6), and primary and secondary arterial thrombosis (n=8). Duration of occlusion was less than 24 hours in seven, 1 to 7 days in ten, and more than 7 days in ten patients. Twelve (44.44%) patients had complete clot lysis, four (14.81%) had partial clearance, and 11 (40.74%) remained occluded. Eight (29.63%) had serious complications including one death. Eighteen (66.66%) patients needed further surgical intervention to maintain graft patency. Data were analyzed using the chi-square and pooled t test. No significant difference was observed in results from thrombolysis from different conduits, gender, etiology, or smoking history. Increased duration of tPA administration was associated with an increased risk of failure. Administration of total dosages greater than 60 mg was associated with a higher risk of failure. Diabetics had a poor outcome (p=0.0520). Only 44 % of patients successfully underwent lysis. A primary surgical option may be a more sensible course than lysis, given that the vast majority of patients ended up having surgery anyway.

Ender nailing for ipsilateral femoral shaft fractures after Austin-Moore hemiarthroplasty.

BACKGROUND: The management of ipsilateral femoral shaft fractures after hemiarthroplasty is controversial. METHODS: Fifteen patients (average age 82.4 +/- 8 years) with ipsilateral femoral shaft fractures after uncemented hemiarthroplasty were treated by closed reduction and Ender nailing. Under radiographic control, closed reduction was attempted. If not possible, cerclage of the shaft fracture was accomplished through a limited lateral approach. Ender nails were then inserted well past the tip of the stem of the prosthesis. RESULTS: There were a superficial wound infection and a deep vein thrombosis. At 6 months, five patients had died, and backing out of the nails necessitated removal in one patient. At 1 year, nine patients were still alive. Of these, seven were able to walk with aids. At 2 years, seven patients were still alive and were walking with aids. Two patients presented shortening of more than 1.5 cm of the operated femur. After an average of 5 years, 11 patients were dead, two were still walking, and two were bedridden. CONCLUSIONS: The technique described is an option in the treatment of fractures of the ipsilateral femoral shaft after uncemented hemiarthroplasty.

Fracture of the shaft of the humerus with a fracture-dislocation of the same shoulder. A case report.

We report the case of a man aged 19 who sustained an anterior dislocation of the shoulder with a fracture of the greater tuberosity, and a fracture of the shaft of the same humerus. Open reduction and internal fixation of the shaft fracture was carried out followed by closed manipulation of the dislocation. He recovered full function of the shoulder and elbow.