2-stage determination of rhesus classification

A new two-staged method for identifying the rhesus appurtenance of the blood is proposed. During the first stage anti-D-super (IgM monoclonal anti-D-antibodies) are used, during the second stage rhesus appurtenance is identified in a tube using standard universal reagent for determining rhesus factor RhO(D) or it is done using gelatin test with Anti-D (IgG monoclonal anti-D-antibodies). A negative result at stage 1 and positive at stage 2 is a sign of partial antigen D, most probably of the VIth category. Subjects with partial D are qualified as rhesus-positive donors and rhesus-negative recipients.     

A role for Bruton's tyrosine kinase (Btk) in platelet activation by collagen

Bruton's tyrosine kinase (Btk) is essential for normal B-cell receptor signalling. The lack of expression of functional Btk in humans leads to the B-cell deficiency X-linked agammaglobulinaemia (XLA). We report here that Btk is also important for signalling via the collagen receptor glycoprotein VI (GPVI) in platelets. GPVI is coupled to the Fc receptor gamma chain (FcRgamma). The FcRgamma-chain contains a consensus sequence known as the immune-receptor tyrosine-based activation motif (ITAM). Tyrosine phosphorylation of the ITAM upon GPVI stimulation is the initial step in the regulation of phospholipase C gamma2 (PLCgamma2) isoforms via the tyrosine kinase p72(Syk) (Syk) in platelets. Here we show that collagen and a collagen-related peptide (CRP), which binds to GPVI but does not bind to the integrin alpha2beta1, induced Btk tyrosine phosphorylation in platelets. Aggregation, dense granule secretion and calcium mobilisation were significantly diminished but not completely abolished in platelets from XLA patients in response to collagen and CRP. These effects were associated with a reduction in tyrosine phosphorylation of PLCgamma2. In contrast, aggregation and secretion stimulated by thrombin in Btk-deficient platelets were not significantly altered. Our results demonstrate that Btk is important for collagen signalling via GPVI, but is not essential for thrombin-mediated platelet activation.     

Prognostic significance of HER-2/neu overexpression in stage I adenocarcinoma of lung

BACKGROUND: Even with early diagnosis and adequate resection, the 5-year survival rate for stage I lung cancer patients is around 60% to 70%. Overexpression of HER-2/neu protein is associated with poor prognosis in lung cancers. In this study, we evaluated the expression of HER-2/neu in cancer cells of lung and assessed their clinicopathologic and prognostic significance. METHODS: From 1986 to 1995, clinical data on 42 consecutive patients who underwent complete surgical resection for stage I lung adenocarcinoma were collected. Expression of HER-2/neu in paraffin-embedded tumor samples was determined by immunohistochemistry and scored with a semiquantitative method. RESULTS: Twenty-one of 42 patients were positive for HER-2/neu overexpression in tumor. Compared with patients with low HER-2/neu expression, patients with HER-2/neu overexpression had a significantly higher incidence of early tumor recurrence (p = 0.014). Survival was also significantly better in patients without HER-2/neu overexpression than in those with HER-2/neu overexpression (p = 0.0047). By univariate analysis, HER-2/neu overexpression and poor cell differentiation are two important factors correlated with poor prognosis. CONCLUSIONS: Expression of HER-2/neu oncoprotein in stage I lung adenocarcinoma can predict the tumor's aggressiveness. Early tumor recurrence was frequently detected in patients with HER-2/neu overexpression. We recommend an individualized therapeutic strategy based on the level of HER-2/neu oncoprotein in the tumor cells.     

Modulation of cell calcium signals by mitochondria

It is now clearer and clearer that mitochondria play a role, and perhaps an active role, in cell calcium signalling. The fact that mitochondria can exhibit a Ca2+-induced Ca2+ release (mCICR, Ichas et al. [37]) reinforces this concept and makes the mitochondria an essential element in the relay of Ca2+ wave propagation. It must be emphasized that the modulation of cell Ca2+ signals by mitochondria depends upon their energetic status, thus making mitochondria an essential link between energy metabolism and calcium signalling inside the cell.     

Expression of beta-amyloid precursor protein immunoreactivity in the retina of the rat during normal development and after neonatal optic tract lesion

Immunoreactivity to beta-amyloid precursor protein (APP) was present in the inner plexiform, ganglion cell and optic fibre layers, as well as in blood vessels, at birth in normally developing rat retinas. In the inner plexiform layer immunoreactivity disappeared by postnatal day (P) 14. A small population of ganglion cells was immunoreactive at birth, but none were visible at P7. From P14 onwards, however, there was weak immunoreactivity in ganglion cells again, and strong staining in Müller glia. Retinas affected by neonatal optic tract lesions contained more immunoreactive ganglion cells at P4 than did controls, but by P14 there was a severe loss of ganglion cells. These observations are consistent with APP being involved in retinal differentiation, including maturation of glia and neurones, synaptogenesis and possibly neuronal survival.