Role of kidney in the catabolic clearance of human platelet antiheparin proteins from rat circulation

Stimulated platelets release at least two antiheparin proteins: platelet factor 4 (PF4) and low affinity platelet factor 4 (LA-PF4) from which beta-thromboglobulin (beta TG) is derived. We have found previously marked elevation of LA-PF4/beta TG antigen in platelet poor plasma of patients with chronic renal failure, whereas levels of PF4 remained normal. Therefore, we examined the role of the kidneys in the metabolic clearance of LA-PF4/beta TG and PF4. The supernates of aggregates of thrombin-stimulated human platelets were injected into sham operated control rats, nephrectomized rats, and into rats with acute ureteral ligation. The disappearance of human LA-PF4/beta TG antigen and PF4 in rat plasma determined by specific radioimmunoassays followed biphasic exponential curves. The half-lives (t1/2) for the fast and slow components of LA-PF4 in control rats were 6.4 and 68.4 min. Nephrectomy significantly increased these times to 9.7 and 144 min, while ureteral ligation resulted in no significant change. Comparison of the level of LA-PF4/beta TG antigen and of creatinine in aorta and in renal vein showed 25%-30% extraction of these compounds by the kidney. Less than 0.1% of the total LA-PF4 antigen injected was recovered in the urine of control rats. In contrast to these results, the clearance of PF4 was not affected by nephrectomy. In conclusion: (1) functional renal tissue is necessary for normal clearance of LA- PF4/beta TG, but renal excretion does not play a major role in its elimination suggesting that the protein is catabolized by the kidney; and (2) catabolic clearance of PF4 does not depend on functioning kidney tissue.     

Endogenous peroxidase in the nuclear envelope and endoplasmic reticulum of human monocytes in vitro: association with arachidonic acid metabolism

The development of peroxidase (PO) reaction in the nuclear envelope (NE) and endoplasmic reticulum (ER) of monocytes differentiating in vitro and its relationship with arachidonic acid metabolism were studied. The PO, as visualized by the diaminobenzidine (DAB) technique, appeared in the NE and ER of the majority of monocytes within 24 hours of culture, with a substantial decrease thereafter. The influence of three major groups of agents--inhibitors of PO, of prostanoids, and of protein biosynthesis--upon the development of the PO reaction was examined. When aminotriazole, a PO inhibitor, was added to the culture medium, the appearance of PO was suppressed in the monocytes. The cyclooxygenase blocker, indomethacin, however, did not influence the development of PO. Also the blockers of protein synthesis, puromycin, cycloheximide, and actinomycin D, did not affect the appearance of PO. The prostanoids released from the monocytes, ie, prostaglandin E and thromboxane B2, were determined by radioimmunoassay and showed a time sequence of secretion that corresponded to the appearance of PO in the cells: a marked increase within the first 24 hours with a substantial decrease thereafter. The presence of the PO inhibitors aminotriazole and sodium azide in the culture medium produced a suppression of prostanoid release from the monocytes comparable with that of indomethacin. The data suggest that the PO in the NE and ER of differentiating monocytes in vitro (1) is associated with arachidonic acid metabolism, and (2) is not formed by de novo protein synthesis but rather by an activation process.     

Clinical impairment in premanifest and early Huntington's disease is associated with regionally specific atrophy

TRACK‐HD is a multicentre longitudinal observational study investigating the use of clinical assessments and 3‐Tesla magnetic resonance imaging as potential biomarkers for future therapeutic trials in Huntington's disease (HD). The cross‐sectional data from this large well‐characterized dataset provide the opportunity to improve our knowledge of how the underlying neuropathology of HD may contribute to the clinical manifestations of the disease across the spectrum of premanifest (PreHD) and early HD. Two hundred and thirty nine gene‐positive subjects (120 PreHD and 119 early HD) from the TRACK‐HD study were included. Using voxel‐based morphometry (VBM), grey and white matter volumes were correlated with performance in four domains: quantitative motor (tongue force, metronome tapping, and gait); oculomotor [anti‐saccade error rate (ASE)]; cognition (negative emotion recognition, spot the change and the University of Pennsylvania smell identification test) and neuropsychiatric measures (apathy, affect and irritability). After adjusting for estimated disease severity, regionally specific associations between structural loss and task performance were found (familywise error corrected, P < 0.05); impairment in tongue force, metronome tapping and ASE were all associated with striatal loss. Additionally, tongue force deficits and ASE were associated with volume reduction in the occipital lobe. Impaired recognition of negative emotions was associated with volumetric reductions in the precuneus and cuneus. Our study reveals specific associations between atrophy and decline in a range of clinical modalities, demonstrating the utility of VBM correlation analysis for investigating these relationships in HD. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.     

Maternal administration of granulocyte colony-stimulating factor improves neonatal rat survival after a lethal group B streptococcal infection

Maternally administered recombinant human granulocyte colony- stimulating factor (rhG-CSF) has been shown to cross the placenta and induce a peripheral neutrophilia and increases in the marrow and spleen neutrophil storage pools in fetal and newborn rats. In the present study, we have used this model system to investigate the efficacy of prenatally administered rhG-CSF on neonatal defense to a lethal challenge with Group B-beta hemolytic Streptococcus (GBS). Pregnant rats were injected with rhG-CSF twice daily beginning 6 days before parturition. At birth, all pups were infected with a dose of GBS that is lethal for 90% of infected pups (LD90). Survival was monitored daily for 5 days. Survival of infected pups from saline-treated mothers beyond 60 hours after infection was 10%. No difference in survival was observed among pups from mothers treated 2 and 4 days before parturition. In contrast, we determined that survival was 82.5% among infected pups from mothers treated for 6 days before parturition with rhG-CSF. Our results demonstrate that maternal administration of rhG- CSF augments neonatal defenses against a lethal bacterial challenge.     

Treatment of achalasia: the short-term response to botulinum toxin injection seems to be independent of any kind of pretreatment

Background  

It has been suggested that intrasphincteric injection of botulinum toxin (BTX) may represent an alternative therapy to balloon dilatation in achalasia. The aim of the present study was to test the effectiveness of botulinum toxin injections in achalasia patients, as assessed using lower oesophageal sphincter pressure (LOSP) and symptom scores, and to compare the response in patients with different types of pretreatment (no previous treatment, balloon dilatation, myotomy, BTX injection).     

In vivo release and turnover of secreted platelet antiheparin proteins in rhesus monkey (Macaca mulatta)

Human and rhesus monkey platelets secrete at least two antiheparin proteins: platelet factor 4 (PF4) and low affinity platelet factor 4 (LA-PF4). Neither of these proteins showed species-related antigenic differences. As determined by radioimmunoassay, the levels of PF4 and LA-PF4 antigen per 10(9) monkey platelets amounted to 10.7 and 20.3 microgram, respectively. One milliliter of monkey plasma prepared from blood collected into an anticoagulant composed of EDTA, prostaglandin E1, and theophylline solution contained 22.4 ng LA-PF4 and 8.0 ng PF4. Concentrations of these two platelet-specific proteins in monkeys closely resembled levels found in human platelets and plasma. Infusion of prostacyclin (PGI2) (100 or 300 ng/kg/min) into monkeys for 15 min resulted in a significant decrease of plasma levels of LA-PF4 antigen and of PF4 by 40%--60% (p < 0.0001). This decrease was related to the inhibitory effect of PGI2 on the secretion of platelets stimulated by a catheter or by venipuncture. Longer infusion of PGI2 did not produce further significant change. The supernate obtained after aggregation of human platelets stimulated by thrombin was injected into monkeys receiving PGI2 infusion. The disappearance of LA-PF4 antigen in monkey plasma followed a biphasic exponential curve with half-lives for the fast and slow components of 8.4 and 63 min. PF4 disappeared faster but followed the same pattern (half-lives for the fast and slow component of 2.1 and 70 min). Analysis of the experimental data suggests that the low levels of secreted platelet proteins in monkey plasma are related to their minimal in vivo release and to their rapid clearance.     

Establishment and characterization of an Epstein-Barr virus transformed cell line with strong phagocytic activity

An immunoglobulin M (IgM)-positive cell line, Ms 28, apparently spontaneously transformed by Epstein-Barr virus (EBV) was established from peripheral blood cells of a patient with immature myeloblastic leukemia. It has been characterized according to phenotype, cytochemistry, and membrane antigen pattern. The cell line expresses lymphoid markers like CD 19, CD 22, and CD 30 and synthesizes and secretes IgM. Monocyte markers CD 11c, CD 14, and CD 15 are absent. Neither interleukin-1 (IL-1), nor tumor necrosis factor (TNF-alpha) are produced. But Ms 28 cells show strong phagocytic activity and engulf Latex particles and sheep RBCs (SRBCs) that need not to be opsonized. The phagocytic activity can be inhibited by chloroquine. Both phagocytosis and EBV nuclear-antigen (EBNA) expression can be observed in one and the same cell. Ms 28 cells might be useful to study immunologic activities like antigen processing and presentation.