Sequential Blood Samples Research Articles

Functional Microparticles Are up Regulated in Patients with Anti-Heparin/Platelet Factor 4 Antibodies: A Potential Mechanism of Thrombogenesis in the Heparin-Induced Thrombocytopenia Syndrome.

Heparin-induced thrombocytopenia (HIT) is one of the most catastrophic adverse effects of heparin therapy, representing a complex syndrome involving immunopathologic and hemostatic disorders. Vascular and blood cellular damage results in the generation of microparticles (MP). These MP are formed from stress conditions/cellular disruption and apoptosis. Cellular MP mediated pathophysiologic responses include platelet activation, up regulation of adhesion molecules, monocyte activation, up regulation of tissue factor and endothelial dysfunction. Several methods based on flow cytometric and other immunologic probes have been used to measure MP in the HIT syndrome. Recently, a functional method based on the complexation of MP with annexin V promoting the generation of factor Xa and thrombin has become available (Hyphen Biomedical, Neuville-Oise, France). To validate the hypothesis that functional MP are elevated in the HIT syndrome, this method was utilized for the quantitation of MP in sera ELISA positive for anti-heparin/platelet factor 4 (HIT) antibodies. Specimens (n = 53) were selected from archived samples that had been referred to Loyola University Medical Center for the laboratory diagnosis of HIT by quantitating anti-heparin/PF4 antibodies by ELISA and by evaluating HIT antibody induced platelet activation using the 14C Serotonin Release Assay (SRA). All selected specimens were positive for HIT antibodies in the GTI PF4 Enhanced ELISA with a broad range of antibody titers (absorbance range of 0.4 – 2.5). Eleven of these specimens were positive in the SRA. In addition, serial samples from HIT patients treated with argatroban (from the ARG-911 clinical study) were included (n = 23). The normal samples represented control sera obtained from healthy human volunteers (n = 25) and processed in the same manner as the clinical samples. Test samples were added to microtiter plates coated with streptavidin and biotinylated annexin V. MP present in the test sample bound to annexin V via exposed surface phospholipids. Following incubation and washing steps, a FXa – FVa mixture containing calcium and prothrombin was added. The assay was optimized so that MP associated phospholipid was the limiting factor for the generation of thrombin. In normal non-HIT sera, the MP levels ranged 5.6 – 10.1 nM (6.1 ± 2.8 nM). The pre-treatment, baseline levels of circulating MP in the suspected HIT patients ranged from 4.2 – 26.8 nM (15.8 ± 7.3 nM). Interestingly, SRA positive/ELISA positive samples had relatively higher levels of MP (19.9 ± 7.7 nM; range 11.5 – 29.8 nM) than SRA negative/ELISA positive samples (14.2± 4.6; range 6.8–21.2). In the ARG-911 study, sequential blood samples exhibited MP levels at the baseline ranging from 8.2 – 38.6 nM (21.8 ± 10.8 nM), whereas after 3 days of argatroban treatment were reduced to 5.1 – 19.2 nM (12.6 ± 6.3). The results of these studies suggest that circulating functional MP are increased in patients with ELISA positive HIT antibodies. Anticoagulation with such direct thrombin agents as argatroban effectively decreases the circulating functional MP levels. Since the elevated MP levels may mediate thrombin and FXa generation, the therapeutic effects of these drugs in HIT may be related to the decreased activation of coagulation and related thrombogenic processes.

MOLECULAR SPECIES OF PROSTAGLANDINS MEDIATING STRESS-INDUCED SUPPRESSION OF GONADOTROPIN SECRETION IN THE BRAIN

It is well established that reproductive function is suppressed under stress conditions. We have previously shown that all the infectious (lipopolysaccharide), hypoglycemic (2-deoxyglucose) and restraint stress suppressed pulsatile release of luteinizing hormone (LH), which was associated with an increase in cyclooxygenase-2 expression in the brain. The suppression of LH pulses by these stressors was much more enhanced by andrenalectomy. On the other hand, both corticosterone and indomethacin similarly attenuated the suppressive effect of the stressors on LH pulses. These observations suggest that prostaglandins (PG) are involved in stress-induced suppression of LH pulses. In the present study, in order to determine which subtype of PGs is involved in suppressing LH pulses, we intracerebroventricularly administered 3 major PG subtypes, i.e. PGF2α, PGD2, and PGE2. We observed LH pulses in ovariectomized rats for 3 hours by sequential blood sampling of 5 min-intervals. PGs were injected 1 h after the start of blood sampling. First, we treated animals with each PG in 3 increasing doses (0.1, 1 and 10 μg). PGF2α did not have any influence on LH pulsatility at all the doses used. PGD2 induced a dose-dependent increase in the amplitude of LH pulses while it did not affect the frequency of LH pulses and mean LH concentrations. On the other hand, PGE2 dose-dependently induced a transient increase and subsequent decreased in both mean LH concentrations and pulse amplitude, and strongly suppressed LH pulse frequency at the highest dose. Secondly, we co-injected PGF2α (5 μg) and PGE2 (5 μg), whose syntheses are known to simultaneously increase under infectious stress conditions. This resulted in a transient suppression of LH pulses in all the 3 parameters; frequency, amplitude, and mean concentrations. These results, together with our previous findings, suggest that PGE2, independently or together with PGF2α, in the brain plays a role in suppressing LH pulses as a common mediator of stressors, and that glucocorticoids maintain reproductive function by decreasing the synthesis of these PGs. (poster)

Retroperitoneal white adipose tissue lipoprotein lipase activity is rapidly down-regulated in response to acute stress

Tissue-specific regulation of LPL has been widely studied in rats. Previous studies reported that in vivo administration of adrenaline and acute stress cause an increase in plasma LPL activity coinciding with a decrease in white adipose tissue (WAT) LPL activity. We studied the speed of LPL activity changes during 30 min of stress by immobilization (IMMO) in rats. A first experimental approach in permanently cannulated rats permitted sequential blood sampling in the same animal during IMMO and the obtaining of hemodynamic parameters. In a second experimental approach, animals were euthanized at different times after the start of IMMO to determine LPL activity in tissues. Stress was characterized by rises in blood pressure, heart rate, plasma corticosterone, and available circulating energy substrates. Five min after the start of IMMO, LPL activity fell in retroperitoneal WAT and increased in plasma. These data show the quickest LPL activity change ever described in response to a physiological situation. The speed and simultaneity of these changes suggest that the release from endothelium to the bloodstream may constitute a fast nonexplored mechanism of tissue LPL activity regulation, involved in the lipid energy-substrate redistribution between tissues needed to prepare the "fight-or-flight" response.

Experimental infection of Atlantic salmon Salmo salar pre-smolts by i.p. injection with new Irish and Norwegian salmonid alphavirus (SAV) isolates: a comparative study

Atlantic salmon Salmo salar L. pre-smolts were experimentally infected with 2 different isolates of salmonid alphavirus (SAV): a Subtype 1 isolate from Ireland and a Subtype 3 isolate from Norway. Sequential samples of tissue and blood were collected during a period of 20 wk post injection and subjected to virus isolation from kidney tissue and serum, detection of viral nucleic acid in heart tissue and serum by real-time RT-PCR, detection of specific antibodies by virus neutralisation assay, and histopathological examination. Successful reproduction of pancreas disease (PD) was obtained by intraperitoneal (i.p.) injection of both isolates. No mortality was observed post infection in either group, but typical PD histopathological lesions in heart and pancreas tissue were observed with both isolates. The prevalence and severity of lesions in the pancreas, heart, skeletal muscle and brain were similar in both groups with only subtle differences recorded. Re-isolation of virus from kidney tissue was performed at 7 and 14 d post infection (d p.i.) only and was positive for both test groups at both sampling points. Isolation of virus from sera from both groups was positive at 4 to 14 d p.i., but was negative at later sampling points when antibody production had begun. Virus may be detected only during the acute phase using both methods. Specific neutralising antibodies could be detected for both test groups from Day 21 p.i. until the end of the experiment at 140 d p.i. Peak antibody titres were seen 70 d p.i. Using real-time RT-PCR, pancreas disease virus (PDV)-specific RNA was detected frequently in serum samples up to 14 d p.i. and occasionally thereafter. In contrast, viral RNA could still be detected in the heart tissue of fish from both groups for at least 140 d p.i.

Breed differences in clearance of porcine FSH in hypophysectomized rats

Extracts of anterior pituitary (AP) glands were infused i.v. into hypophysectomized male rats followed by sequential sampling of blood for 120 min. Determination of follicle-stimulating hormone (FSH) concentrations established that FSH from Chinese Meishan males decreased in the circulation of rats more slowly than FSH in extracts of AP from crossbred occidental pigs ( P < 0.003). Additionally, FSH from AP extracts of castrated males disappeared somewhat more slowly ( P < 0.06) than FSH from extracts of boars. Evaluation of FSH by bioassay and radioimmunoassay yielded similar concentrations in AP from Meishan and crossbred boars. Serum testosterone concentrations increased with time through 90 min after infusion of AP, but the rate of increase of testosterone was not related to amount of luteinizing hormone (LH) that was administered indicating LH receptor saturation. Unexpectedly, the rate of increase in testosterone was more rapid with AP extracts from boars than with extracts from castrated males. Observations from the current study imply structural alterations of FSH in the AP of Meishan males relative to crossbred males allowing sustained concentrations in the circulation, and this FSH possesses similar activation of the FSH receptor. The amount of LH in the AP extracts saturated the LH receptors of the hypophysectomized male rats, but some factor in extracts of boars differed from those of castrated males.

Plasma Concentration of Insulin-like Growth Factor I (IGF-I) in Growing Ardenner Horses Suffering from Juvenile Digital Degenerative Osteoarthropathy

Degenerative osteoarthropathy resulting in a reduced active lifespan was observed in Ardenner horses. In the context of joint biology, insulin-like growth factor I (IGF-I) is a potential candidate to affect the anabolism of cartilage matrix molecules. A group of 30 Ardenner horses reared under standardized conditions from weaning were evaluated periodically from 15 to 28 months of age to detect the early manifestations of the disease. At the end of this period, horses were classified in two pathological groups related to the degree of interphalangeal degenerative osteoarthropathy based on clinical and radiographic evaluations: healthy (46.7%) and pathological (53.3%) horses. Seven sequential blood samples were taken from each horse (during the evaluation period) to study the variation of IGF-I plasma concentration. We tested the variations of the IGF-I plasma concentration during growth, and the effect of sex and of pathological classes. Significant variations were observed during the research period, with a maximum value corresponding to spring and a minimum in autumn. A significant reduction of the IGF-I plasma concentration was also observed in the pathological horses (433.5 +/- 19.5 ng/ml) compared to the healthy horses (493.9 +/- 18.2 ng/ml). An alteration in the level of this growth factor could induce a disregulation of the mechanisms involved in the local control of joint and bone tissue development.

Luteinizing hormone release after administration of the gonadotropin-releasing hormone agonist Fertilan (goserelin) for synchronization of ovulation in pigs

The generic GnRH agonist, Fertilan (goserelin), was tested for the ability to induce an LH surge and ovulation in estrus-synchronized gilts. Three experiments were performed to 1) examine the effect of various doses of Fertilan on secretion of LH in barrows, to select doses to investigate in gilts (Exp. 1); 2) determine doses of Fertilan that would induce a preovulatory-like rise of LH in gilts (Exp. 2); and 3) determine the time of ovulation after Fertilan treatment (Exp. 3). In Exp. 1, 10 barrows were injected on d 1, 4, 7, 10, and 13 with 10, 20, or 40 microg of Fertilan; 50 microg of Gonavet (depherelin; GnRH control) or saline (negative control); and sequential blood samples were collected for 480 min. There was a dose-dependent stimulation (P < 0.05) of LH release. Maximal plasma concentrations of LH (LH(MAX)) were 2.1 +/- 0.2, 4.1 +/- 0.3, 2.6 +/- 0.4, and 3.4 +/- 0.3 ng/mL after 10, 20, and 40 microg of Fertilan and 50 microg of Gonavet, respectively, and duration of release was 78 +/- 9, 177 +/- 12, 138 +/- 7, and 180 +/- 11 min, respectively. Fertilan doses of 10 and 20 microg were deemed to be the most suitable for testing in gilts. In Exp. 2, 12 gilts received (after estrus synchronization with Regumate and eCG) injections of 10 or 20 microg of Fertilan or 50 microg of Gonavet 80 h after eCG to stimulate a preovulatory-like LH surge and ovulation. An LH surge was induced in 3 of the 4 gilts in both of the Fertilan groups and in all of the Gonavet-treated gilts. Characteristics of induced release of LH did not differ among groups: LH(MAX), 5.0 +/- 0.9 vs. 4.6 +/- 1.8 vs. 6.6 +/- 1.1 ng/mL; duration, 11.7 +/- 2.0 vs. 12.3 +/- 2.2 vs. 14.3 +/- 0.5 h; interval from GnRH injection to LH(MAX), 4.0 +/- 2.0 vs. 6.7 +/- 1.3 vs. 5.8 +/- 1.6 h. In Exp. 3, estrus-synchronized gilts were injected with 20 microg of Fertilan (n = 8) or 50 microg of Gonavet (n = 4), and the time of ovulation was determined by repeated endoscopic examination. Time of ovulation ranged from 34 to 42 h postGnRH; however, ovulation occurred earlier in the Gonavet compared with the other groups (P < 0.05). Results of these experiments indicate that 1) barrows are an appropriate model for determining GnRH doses that can be effective in inducing a preovulatory-like LH surge in females; 2) the generic GnRH agonist Fertilan, at doses of 10 to 20 microg, can stimulate an LH surge in gilts, with subsequent ovulation; and 3) Fertilan at doses of 10 and 20 microg should be examined further for use in fixed-time insemination protocols.

The temporal program of peripheral blood gene expression in the response of nonhuman primates to Ebola hemorrhagic fever

Primate blood cells were analysed for changes in global gene expression patterns at several time points following infection with Ebola virus, providing insights into potential mechanisms of viral pathogenesis and host defense.

Pharmacokinetics and Tolerability of??Duloxetine following Oral Administration to Healthy Chinese Subjects

The objectives of the study were to characterise the pharmacokinetics and assess the tolerability of duloxetine in healthy Chinese subjects after single and multiple oral 60 mg dosing. This was a single-centre, double-blind, randomised, placebo-controlled, single-period study in healthy native Chinese subjects. A total of 32 subjects, 19 men (14 on duloxetine, 5 on placebo) and 13 women (10 on duloxetine, 3 on placebo) between the ages of 20 and 39 years, participated in the study. Duloxetine 60 mg (enteric-coated pellets in a capsule) was given orally once on day 1 and once daily on days 4 to 9. Sequential blood samples were collected over 72 hours after the dose on days 1 and 9, and a predose sample was obtained on days 7 and 8. Duloxetine concentrations in plasma were determined by a validated liquid chromatography-tandem mass spectrometry method. The tolerability evaluation included a physical examination, vital signs, adverse event monitoring and clinical laboratory evaluations. Duloxetine disposition on oral administration is characterised by a one-compartment pharmacokinetic model. Duloxetine is well absorbed, with a median time of maximum plasma concentration at 6 and 4 hours following single and multiple dosing, respectively. At steady state, the mean apparent oral clearance (CL(ss)/F), mean apparent volume of distribution (V(ss)/F) and mean terminal elimination half-life (t((1/2))) were 86.8 L/h, 1570L and 11 hours, respectively. CL/F and V(ss)/F on single dosing were not statistically significantly different (p > 0.05) compared with multiple dosing. The linearity index, calculated as the ratio of the area under the plasma concentration-time curve (AUC) during the dosing interval tau at steady state (AUC(tau)(,ss)) to the AUC from time zero to infinity after single dosing (AUC(infinity,single dose)) was 1.15 (coefficient of variation 35.7%). The accumulation in duloxetine exposure was estimated to be 50% on multiple dosing compared with single dosing, consistent with the t((1/2)) and dosing interval (24 hours). The pharmacokinetic parameters of duloxetine in Chinese subjects were not statistically significantly different from those reported previously in Caucasian and Japanese subjects. There were no clinically significant adverse events, abnormal safety laboratory data or vital sign changes reported. Duloxetine pharmacokinetics in healthy Chinese subjects given a 60 mg once-daily dosing regimen were well characterised and consistent with known duloxetine pharmacokinetics in healthy Caucasian and Japanese subjects. Both single dosing and multiple once-daily dosing of duloxetine 60 mg were well tolerated by healthy Chinese subjects in this study.

Analysis of NF‐κB Nuclear Translocation in PMN‐neutrophils of Major Trauma Patients in the Early Post‐traumatic Period: A Pilot Study

Post-traumatic inflammation is connected to polymorphonuclear neutrophil (PMN)-dysfunction characterized by reduced nuclear translocation of NF-kappaB during the post-traumatic period. However, the dynamic of NF-kappaB translocation in PMN of major trauma patients remains unclear. Hence, the aim of this pilot study was to analyze NF-kappaB in PMN from multiply injured patients immediately after trauma. Blood samples of major trauma patients (ISS > 16) were drawn on admission within 90 minutes after trauma and at 6, 12, 24, 48, and 72 hours after trauma. Neutrophilic NF-kappaB-translocation was analyzed by EMSA and quantified by densitometry as (arbitrary units). In addition, PMN of healthy volunteers were analyzed either in their native state (-control) or after LPS stimulation (+control). Twelve patients (NISS: 34 +/- 10 [mean +/- SEM]) were enrolled. NF-kappaB translocation was significantly increased in trauma patients on admission and after 6 hours. Interestingly, a second activity peak was present after 24 hours. In patients who later died, NF-kappaB activity was significantly elevated initially, to be rapidly diminished after 6 hours, while it increased in the survivors group. After 24 hours NF-kappaB activity increased significantly in the survivors group, to become reduced in both groups at a later time. Within this pilot study, the dynamic of NF-kappaB translocation in PMN of multiply injured patients immediately after trauma was analyzed for the first time. Enabled by closely matched sequential blood sampling strictly standardized to the traumatic event, an essential biphasic increase of neutrophilic signal transduction could be investigated in the very early post-traumatic period, which preceded the downregulation of the innate immune system.

Extracellular accumulation of bioactive substances; Interleukin-1β (IL-1β) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and relation to bacterial contamination

Bacterial contamination of blood and its cellular components remains an unresolved problem in transfusion medicine and is considered to be the most common microbiological cause of transfusion associated morbidity and mortality.The present work was designed to explore the levels of two bioactive compounds interleukin-1 β (IL-1 β) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and their relation to bacterial contamination of these units.This study was conducted on 112 blood units obtained from blood bank of Mansoura University Children Hospital. Sequential blood samples were obtained both immediately at donation and after 10 days for measurement of IL-1 β and PAI-1 and for bacterial culture by BACTEC 9050 system.There was statistically significant increase in both IL-1 β and PAI-1 (P = 0.0001) after 10 days of blood units storage. Bacteriological culture revealed no growth in 68% and positive growth in 32% of blood units. The commonest isolated organism was Staphylococcus aureus (15%) followed by Staphylococcus epidermedis (13%) then Yersinia sp. and Enterobacter sp. (2%) for each.From the present study we could conclude that stored blood units contain platelets and WBCs derived bioactive substances PAI-1 and IL-1 β which increase with the duration of blood storage. Furthermore, the extended duration of storage carries the danger of blood contamination by bacteria. Automated blood culture system seems to be helpful in identification of bacterial contamination of blood units. We recommend fresh blood transfusion as early as possible and the practice of Leucofiltration to avoid blood transfusion complications.

Quantification of Protein Metabolism in Vivo for Skin, Wound, and Muscle in Severe Burn Patients

In response to injury, muscle catabolism can be extensive, and in theory, the wound consumes amino acids to support healing. The purpose of this study is to assess a technique by which in vivo protein kinetics of muscle, wound, and normal skin can be quantified in burn-injured patients. Study protocol consisting of infusion of d5 phenylalanine; biopsies of skeletal muscle, skin, and donor-site wound on the leg; quantification of blood flow to total leg, wound, and skin; and sequential blood sampling from the femoral artery and vein. Five-compartment modeling was used to quantify the rates of protein synthesis, breakdown, and phenylalanine transport between muscle, wound, and skin. The study results demonstrated a net release of phenylalanine from muscle yet a net consumption of phenylalanine by the wound. Compared with skin, the wound had a substantially increased rate of protein synthesis and a reduced rate of protein breakdown (p < .01). Transport rates into and out of muscle were significantly higher than those for wound (p < .01). This novel methodology enables in vivo quantification of the integrated response of muscle, wound, and skin protein/amino acid metabolism and confirms the long-held theory of a net catabolism of muscle and a net anabolism of wound protein in patients after injury. This methodology can be used to assess the metabolic impact of such measures as nutrition, pharmacologic agents, and surgical procedures.

Determinazione quantitativa di HIV-1 DNA nel follow-up del paziente HIV-1 infetto: esperienza in un gruppo di soggetti HIV-1 infetti

Proviral HIV-1 DNA can represent an alternative viral marker to RNA viral load during the follow-up of HIV-1 infected individuals. Sequential blood samples of 12 patients under antiretroviral treatment from 1997 with two NRTIs, who refused to continue any antiviral regimen, were analyzed for 16-20 weeks to study the possible relationship between DNA and RNA viral load. Results obtained showed an increase or a rebound in viral DNA, quantified by SYBR green real-time PCR in peripheral blood mononuclear cells in most patients, suggesting that the absence of therapy reflects an increase and/or a persistence of cells containing viral DNA. Even though plasma HIV RNA levels remain the basic parameter to monitor the intensity of viral replication, the results obtained seem to indicate that DNA levels could represent an adjunct prognostic marker in monitoring HIV-1 infected subjects.

Bone turnover markers in postmenopausal breast cancer patients treated with fulvestrant

680 Background: Aromatase inhibitor (AI) therapy in patients with breast cancer accelerates bone turnover with increased secretion and excretion of bone turnover markers. Here, we report the effect of fulvestrant, an estrogen receptor (ER) antagonist with no agonist activity, on bone metabolism. Methods: 23 patients with either locally advanced primary [LAPC] or metastatic [MBC] disease who had clinical benefit (objective response/stable disease ≥6 months) during fulvestrant therapy were included in the study. Sequential tumor biopsies and blood samples were taken at baseline and after 3, 6, 9, 12 and 18 months of fulvestrant treatment (disease being stable throughout the study period). Serum was analyzed for bone formation markers (N-terminal propeptide of procollagen Type 1 [PINP] and bone-specific alkaline phosphatase [bone ALP]) and for the resorption marker C-terminal telopeptide (CTX). Data are presented as median percentage change (from baseline) in marker level with 95% confidence intervals (CI). Data were analyzed separately for patients with LAPC and MBC. Results: Changes in bone ALP (reference range: 3.9–46.8 ng/mL), PINP (20.6–82.1 ng/mL) and CTX (0.14–1.35 ng/mL) in patients with LAPC, are shown in the table . In a further 5 patients with LAPC who were already established on fulvestrant, there were no significant changes in markers over a 15-month period. No changes in markers were noted in the 4 patients with MBC. Conclusions: In this study, there was long-term stability of bone turnover markers in postmenopausal women with LAPC treated with fulvestrant over a period of 18 months. This property may be exploited in future with the use of fulvestrant earlier in the sequence of endocrine therapies particularly in the adjuvant setting and/or in patients with pre-existing decreased bone mass. [Table: see text] [Table: see text]

Several herpesviruses can reactivate in a severe drug-induced multiorgan reaction in the same sequential order as in graft-versus-host disease

Drug-induced hypersensitivity syndrome (DIHS) is a severe multiorgan systemic reaction. Numerous studies have linked reactivation of human herpesvirus (HHV)-6 with the development of DIHS. Recent articles have suggested that reactivation of other herpesviruses besides HHV-6 might also be involved in the development of DIHS. On the other hand, recent studies have provided evidence for a role of reactivation of various herpesviruses in the development of graft-versus-host disease (GVHD). We attempted to determine whether sequential herpesvirus reactivation could be detected in four patients with severe DIHS, as observed in patients with GVHD, and be coincident with various clinical manifestations that developed after discontinuation of the causative drugs. Detection and quantification of viral DNA [cytomegalovirus (CMV), Epstein-Barr virus (EBV), HHV-6 and HHV-7] in sequential blood samples were performed using real-time polymerase chain reaction assays, based on TaqMan technology. In these patients, the cascade of virus reactivation initiated by HHV-6 or EBV extended to EBV or HHV-7, and eventually to CMV. Clinical manifestations of this syndrome followed by failure of various organs occurring despite discontinuation of the drug were coincident with these herpesvirus reactivations. These results suggest that various herpesviruses can reactivate in the setting of severe drug reactions in a similar sequential order to that described in GVHD. The sequential reactivation of these herpesviruses is responsible for the development of multiorgan failure occurring after discontinuation of the causative drug.

The Morphology and Cellular Characterization of Thrombocytes in Adult Xenopus laevis.

In primates and rodents, platelets originate from the bone marrow megakaryocytes through a unique differentiation process with nuclear polyploidization, cytoplasmic maturation and proplatelet formation. In contrast, circulating thrombocytes of most non-mammalian vertebrates are particularly distinctive; the cells are large and nucleated. Adult Xenopus laevis may be an useful non-mammalian model for analyzing dynamic hematopoiesis because they are individually tolerable for time lapse analysis in vivo with sequential blood sampling, whereas classification of cell types has not been established yet. Microstructures of Xenopus thrombocytes observed with electron microscope exhibited structural characteristics largely resembling zebrafish thrombocytes with nucleated spindle cellular features (Thattaliyath et al., Blood 2005), and they had lobulated nuclear chromatin, granules, microparticles and open canalicular system-like-structures as in mammalian megakaryocytes. Since thrombocyte identification based on the morphological aspect was not sufficient, chemical staining with acetylecholinesterase and thiazole orange were performed. Additionally, mice were immunized by Xenopus peripheral blood cells to generate monoclonal antibodies, and two hybridomas producing IgG, respectively T12 and T5, were screened. T12+ (T12 positive) cells were morphologically typical thrombocytes. Flow cytometric analysis revealed that T12+ cells were also positive to anti-human GpIIb/IIIa polyclonal antibodies, and approximately 2-3% of whole peripheral blood cells were T12+/GpIIb/IIIa+ that distributed in FSClow/SSClow fraction. When T12 was injected into Xenopus to deplete T12+ cells in vivo, the detectable level of T12 in the circulation lasted for more than several weeks. Peripheral thrombocyte counts predominantly began to decrease immediately and reached their nadir at day 3, but white blood cell counts were not changed. RNA-rich blood cells considered as younger cells were then increasingly appeared, and finally the cell counts recovered to normal levels at day 10–15, indicating that in vivo depletion of T12+ cells induced thrombopoiesis and/or release of mature thrombocytes from the pool. T5 recognizing cells were classified into two populations by immunostaining and flow cytometry; T5+/GpIIb/IIIa+ cells were morphologically thrombocytic as the cells recognized by T12, while T5+/GpIIb/IIIa− cells were spherical and similar appearance to lymphocytic cells. These observations raised some possibilities e.g.; antigen of T5 was a membrane protein common to both lymphocytes and thrombocytes, or T5+/GpIIb/IIIa− cells were thrombocyte progenitors at earlier development stage than T12+/GpIIb/IIIa+ cells. Nevertheless only a few percent of T12+ and T5+ cells resided in peripheral blood, immunostaining revealed that the proportions of T12+/T5+ and T5+ cells in spleen were 10% and 70%, and T12+/T5+ and T5+ cells in liver were 5% and 20%, respectively. These suggest that spleen is predominantly involved in thrombopoiesis and/or thrombocyte storage in adult Xenopus. As T12 and T5 can be used successfully in flow cytometry and magnetic cell sorting, they should contribute us directly to elucidate the origin of circulating Xenopus thrombocytes and their cellular development process.

The Prevalence of Chronic Lymphoproliferative Diseases in Patients with Borderline Lymphocytosis in Community Practice.

Introduction: The standard criterion for diagnosing chronic lymphocytic leukemia (CLL) is clonal lymphocytosis of >5×10 9/L. Cases of CLL with normal lymphocyte count have been diagnosed by flow cytometry based on the presence of clonal CD19+/CD5+/CD23+ cells. Therefore, it is not unexpected that a proportion of patients with borderline lymphocytosis (>3.5 and <5.0x10 9/L) will have CLL. The aim of our study is to establish the prevalence of CLL in patients with borderline “4.0 to 5.0x109/L” lymphocytosis in the adult population (age >40 years) seen in community practice.Methods: Using flow cytometry we analyzed a total of 157 sequential peripheral blood samples collected from patients older than 40 years presented with borderline lymphocytosis (4 to 5 x109/L). Majority of these patients (#106) were detected incidentally during routine CBC and 51 samples were submitted to rule out lymphoproliferative diseases.Results: Forty of the 157 (26%) patients had clonal B-cell disease meeting the criteria for chronic lymphoproliferative disease. The disease was classified as CLL in 35 patients (87.5%), hairy cell leukemia in 1 patient (2.5%), Waldenstrom's macroglobulinemia in 1 patient (2.5%) and marginal zone B-cell lymphoma in 3 patients (7.5%). This data suggests that patients older than 40 year with lymphocyosis >4x10 9/L have high probability of having chronic lymphoproliferative disease. This disease could be other than CLL and should be thoroughly investigated.DISCUSSION: In our study the prevalence of low grade lymphoproliferative disorders in patients with borderline lymphocytosis (4–5 x109/L) above the age of 40 is 26%. This number may be positively skewed considering our selection criteria (including a subset of patients retrospectively included).Currently, there is no data to support that early intervention is beneficial for CLL, even for patients with unfavorable prognosis (e.g., those with ATM and P53 deletions). Early diagnosis of CLL will create more opportunity to study the disease in its early stages.[Shanafelt TD, Geyer SM, Kay NE: Prognosis at diagnosis: integrating molecular biologic insights into clinical practice for patients with CLL. Blood. 2004 Feb 15;103(4):1202–10. Epub 2003 Oct 23. Review.], [ Hamblin TJ: Achieving optimal outcomes in chronic lymphocytic leukemia. Drugs . 2001; 61(5):593–611. Review.]. Since lymphocyte doubling time (LDT) is a prognostic factor (the prognostic utility of LDT is most important for patients with early stage disease who typically are treated by watchful waiting [ Shanafelt TD, Call TG. Current approach to diagnosis and management of chronic lymphocytic leukemia. Mayo Clin Proc. 2004 Mar;79(3):388–98. Review. ] ). early diagnosis may help to better segregate low from high-risk patients. Finally, in today's cost containment pressures, it is beneficial to have an expectation for the cost/benefit ratio of performing a test. Knowing the prevalence of disease at decision limits may help us to better justify establishing testing guidelines.

A Novel Flow Assay for the Detection of Cytokine Secreting Alloreactive T Cells: Application to Immune Monitoring

The direct and indirect allorecognition pathways play an important role in graft rejection. We hypothesized that the presence of alloreactive memory T cells in the recipient’s circulation increases the risk of rejection after transplantation. The objective of this study was to develop a noninvasive, immune monitoring tool that simultaneously measures donor-specific responses via both the direct and indirect recognition pathways. Our laboratory developed a whole blood flow cytometric cytokine secretion assay to identify interferon (IFN)-γ secreting memory T cells in whole blood of renal transplant patients. The assay readily detected IFN-γ producing CD3+ T cells in response to recall antigens tetanus toxoid, purified protein derivative, and alloantigens in whole blood from healthy controls. Analysis of sequential posttransplant blood samples from 19 renal allograft recipients showed that alloimmune responses were higher in transplant recipients who had undergone acute rejection than in those without acute rejection episodes. In addition, patients showing increased creatinine levels 3 months after transplantation were more likely to exhibit alloimmune responses than recipients with stable graft function. The flow cytokine secretion assay provides a reliable and simple method for identification of patients at risk of acute rejection and early graft dysfunction.

Apoptosis of peripheral blood neutrophils in COPD exacerbation does not correlate with serum cytokines

The study investigated the relationship between apoptosis of peripheral blood neutrophils during exacerbation of chronic obstructive pulmonary disease (COPD) and the inflammatory response that characterises this condition. Twenty-six hospitalised patients with COPD exacerbation and 13 controls were included. Three sequential blood and sputum samples were obtained from patients at admission, after 3 days and at discharge. Blood apoptotic neutrophils were measured by flow-cytometry and light microscopy. Serum and sputum levels of IL-6, IL-8 and TNF-alpha were determined by an immunoassay technique. We found a significantly reduced percentage of apoptotic neutrophils at the onset of COPD exacerbation which increased over time (1.1+/-0.4% at admission vs. 2.4+/-0.4% at discharge, P<0.0001). Patients presented no changes in serum cytokines neither during exacerbation nor in comparison to controls. In contrast, sputum levels of cytokines were significantly increased compared to serum levels. There was no significant correlation between the apoptotic neutrophils and the cytokine concentrations in serum or sputum. None of the clinical parameters, such as smoking, microbial infection, corticosteroids or hypoxemia showed a correlation with neutrophil apoptosis. No relationship could be found between the reduced percentage of apoptotic neutrophils in blood and serum concentration of IL-6, IL-8 and TNF-alpha or other clinical parameters in patients with COPD exacerbation.

Different patterns of HIV-1 DNA after therapy discontinuation

BackgroundBy persisting in infected cells for a long period of time, proviral HIV-1 DNA can represent an alternative viral marker to RNA viral load during the follow-up of HIV-1 infected individuals. In the present study sequential blood samples of 10 patients under antiretroviral treatment from 1997 with two NRTIs, who refused to continue any antiviral regimen, were analyzed for 16 – 24 weeks to study the possible relationship between DNA and RNA viral load.MethodsThe amount of proviral DNA was quantified by SYBR green real-time PCR in peripheral blood mononuclear cells from a selected group of ten patients with different levels of plasmatic viremia (RNA viral load).ResultsVariable levels of proviral DNA were found without any significant correlation between proviral load and plasma HIV-1 RNA levels. Results obtained showed an increase or a rebound in viral DNA in most patients, suggesting that the absence of therapy reflects an increase and/or a persistence of cells containing viral DNA.ConclusionEven though plasma HIV RNA levels remain the basic parameter to monitor the intensity of viral replication, the results obtained seem to indicate that DNA levels could represent an adjunct prognostic marker in monitoring HIV-1 infected subjects.