Rothia dentocariosa is a rare cause of endocarditis. It occurs most frequently in patients with prior heart conditions. Although the clinical course is typically subacute, it has a high rate of complications. In particular, the reported incidence of mycotic aneurysms is as high as 25%. Penicillin is the treatment of choice, but additional complications may necessitate prompt surgical intervention. As far as we know, this paper reports the first case of repeated subarachnoid hemorrhages due to R. dentocariosa endocarditis.
Although healthy neonates do not show a clinical bleeding tendency, in vitro tests of neonatal platelet function (aggregometry and flow cytometry) demonstrate hyporeactivity compared with platelet function in adults. This is in contrast to the in vivo bleeding time which is shorter in neonates than adults [4]. The Platelet Function Analyser PFA-100 is an in vitro test for the evaluation of the global process of platelet adhesion and aggregation in whole blood, based on the combination of high shear stress and chemical agonists: collagen combined with epinephrine (COL/EPI) and with adenosine phosphate (COL/ADP). Results are reported in seconds as closure time (CT), the in vitro equivalent of the bleeding time [5]. Our aim was to establish neonatal reference ranges for the PFA-100 in cord blood using a large study group and to compare these with values in adults. A few studies have addressed the evaluation of neonatal platelet function with the PFA-100, but they included smaller numbers of samples [1, 2, 3, 6].The study was performed on citrated whole blood (1 part 3.8% sodium citrate to 9 parts blood) drawn with a 21 gauge needle. Cord blood samples were collected from the umbilical cord vein within 5 min of delivery in 80 full-term neonates (gestational age >37 weeks). The mothers had a history of uncomplicated pregnancy and were not on medication known to affect platelet function. The neonates had Apgar scores of ‡7 at 1 min and ‡9 at 5 min and were without evidence of congenital or acquired illness. Blood samples were collected from an antecubital vein in 20 healthy adults to validate adult reference ranges (COL/EPI CT: 85-165 s, COL/ADP CT: 72-120 s). Blood was assayed within 4 h of collection.In cord blood, the central 95% reference range (with 90% confidence intervals) was 49-168 s (±9.5 s) for COL/EPI CT and 40-92 s (±4.5 s) for COL/ADP CT (Table 1). Compared with adult reference ranges, both the neonatal COL/EPI and COL/ADP CT reference ranges were shorter (two-sample t-test, P<0.001).Our in vitro results are compatible with the reported shorter in vivo bleeding times in neonates compared with adults [4]. Although similar findings with the PFA-100 have been made in smaller groups of neonates, a significant difference in the CTs of neonates and adults could not always be demonstrated [1,2,3,6]. Haematocrit values are consistently higher in neonates than in adults, but have been shown to only marginally explain the observed difference [2,3]. Another consistent difference is the increased neonatal presence of high molecular weight multimers of the von Willebrand factor (vWF) [4]. vWF plays an important role in primary platelet related haemostasis allowing platelet adhesion, especially under high shear stress conditions as in the PFA-100 [5]. A recent experimental study provided evidence of this role of vWF on CTs in neonates [6]. Finally, one has to be aware of potential pitfalls in the use of the PFA-100, especially the lack of control of preanalytic variables: both the concentration of sodium citrate used a...
Clonality is a frequently exploited characteristic of lymphoid malignancies. However, in the natural killer (NK) cell subset of large granular lymphocyte proliferations, clonality is difficult to prove because of the lack of specific genetic markers, such as immunoglobulin or T-cell receptor gene rearrangements. The human androgen receptor (HUMARA) assay, a polymerase chain reaction-based X-chromosome inactivation assay, is a potential diagnostic tool in these disorders. Although there is much experience with X-chromosome inactivation assays in myeloid proliferations, these assays have found only very limited application in clonality assessment of NK cell proliferations. We applied the HUMARA assay in laboratory diagnostics for detection of clonality in NK cell proliferations. We describe its test performance and report three cases in which clonality of NK cell populations was investigated by use of this assay. Our results demonstrate the usefulness of the HUMARA assay in the diagnostic workup of NK cell proliferations. (J Mol Diagn 2007, 9
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