Method of quantitative measurement of human platelet aggregation in clinical practice

We examined the quantitative measurement of platelet aggregation in 20 volunteers and 89 patients with ischemic heart disease (IHD). Subjects in whom platelet aggregation was induced by an adenosine diphosphate (ADP and an epinephrine solution were clearly divided into two groups: "normal" and "accentuated". We chose the maximum aggregation time for the ADP solution and the maximum transmission rate for the epinephrine solution for the quantitative measurement of platelet aggregation. The results were as follows. The maximum aggregation time with a 1.0 microM ADP solution in the normal group of 13 volunteers was 0.71 +/- 0.12 min, (mean +/- SD), in 50 IHD patients it was 0.91 +/- 0.49 min, in the "accentuated" group of 7 volunteers it was 5.34 +/- 1.18 min, in 39 IHD patients it was 6.01 +/- 1.22 min. The maximum light transmission rate with a 0.1 microM epinephrine solution in the normal group of 14 volunteers was 8.04 +/- 4.14%, in 52 IHD patients it was 13.74 +/- 5.75%, in the "accentuated" group of 6 volunteers it was 76.33 +/- 9.91%, and in 37 IHD patients it was 77.26 +/- 13.39%. The difference between the "normal" and "accentuated" groups was statistically significant (p < 0.001), with the ADP and with the epinephrine solution. Next, we examine the effect of antiplatelet therapy (dipyridamole and aspirin) on 15 patients selected from among those with IHD who had accentuated platelet aggregation when the ADP solution was added. Their maximum aggregation time was 5.98 +/- 1.24 min, and their maximum platelet aggregation rate when the epinephrine solution was added was 78.90 +/- 11.60% (10 patients), 20.00 +/- 3.24% (5 patients). After the therapies, the maximum aggregation time in 10 patients was 0.94 +/- 0.21 min (return to normal condition), and in 5 patients it was 5.90 +/- 1.09 min (not effective). The maximum platelet aggregation rate in 10 patients was 14.11 +/- 5.88% (normal condition), and in 5 patients it was 75.00 +/- 9.51% (not effective). Finally, we examined the long term effects of various antiplatelet drugs. Most of the patients in whom platelet aggregation was accentuated got well.     

Antibody assay for adenoviruses and mycoplasma pneumoniae by the platelet aggregation test

The practicability of the platelet aggregation test (PAT) in routine antibody assays for adenoviruses and Mycoplasma pneumoniae is demonstrated. An increase in reliability and sensitivity was achieved by employment of EDTA for washing the platelet and by addition of albumin to the test medium. Various lots of platelets yielded reproducible PAT titres which attained 1 : 156,250 in positive patient's sera. Commercially available antigens assigned for complement-fixation (CF) tests proved to be appropriate for the PAT. Checkerboard titrations revealed that the platelet reactivity of immune complexes formed was maintained in a range of up to 625-fold alterations of the antibody: antigen ratio. The fact that PAT and CF titres did not always correlate is interpreted as being due to the differences between complement-fixing and platelet reactivities of various immunoglobulin classes.     

Waterjet dissection of the brain: experimental and first clinical results. Technical note

Axons from central neurons can regenerate into the tissue matrix formed within a silicone tube capped with two pieces of peripheral nerve, one of which had been sutured to a lesion in the spinal cord. Such axons can grow through a transversely positioned microchip in the tube. These observations suggest that it is feasible to establish functional contact between external electronic equipment and regenerating central nervous axons making it possible to monitor and control their electrical activity. The findings open new perspectives for restoration of motor and sensory functions following spinal cord lesions.     

The meanings and measurement of clinical significance.

The previous articles in this special section (P. C. Kendall et al, see record 1999-03648-001; N. S. Jacobson et al, see record 1999-03648-002; S. L. Foster and E. J. Mash, see record 1999-03648-003; and M. M. Gladis et al, see record 1999-03648-004) make the case for the importance of evaluating the clinical significance of therapeutic change, present key measures and innovative ways in which they are applied, and more generally provide important guidelines for evaluating therapeutic change. Fundamental issues raised by the concept of clinical significance and the methods discussed in the previous articles serve as the basis of the present comments. Salient among these issues are ambiguities regarding the meaning of current measures of clinical significance, the importance of relating assessment of clinical significance to the goals of therapy, and evaluation of the construct(s) that clinical significance reflects. Research directions that are discussed include developing a typology of therapy goals, evaluating cutoff scores and thresholds for clinical significance, and attending to social as well as clinical impact of treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Sebastian platelet syndrome. Report of the first native Saudi Arabian patient

Sebastian platelet syndrome is an hereditary thrombocytopenia with giant platelets and inclusion bodies in the granulocytes consisting of dispersed filaments, clusters of ribosomes and a few segments of rough and smooth endoplasmic reticulum at the ultrastructural level, similar to those observed in Fechtner syndrome (a variant of the Alport syndrome)--Sebastian platelet syndrome lacks the additional clinical features such as high frequency deafness, congenital cataract, and chronic interstitial nephritis. Here we report the fourth case worldwide and the first of an Arabian ancestry.     

Hydrodynamic thrombectomy of hemodialysis fistulas: first clinical results

PURPOSE: A hydrodynamic thrombectomy system was used for the treatment of recent dialysis shunt thrombosis. PATIENTS AND METHODS: Sixteen shunt thromboses in 14 patients were included in the study. There were seven polytetrafluoroethylene grafts and nine native arteriovenous fistulas. Occlusion time ranged from 6 to 48 hours, and thrombus length ranged from 4 to 40 cm. RESULTS: Thrombectomy was technically successful in 15 of 16 instances. No significant residual thrombus was found in 15 cases. In one case, half of the thrombus remained in the vessel and the procedure failed technically. One embolus to the radial artery occurred after balloon dilation following hydrodynamic thrombectomy and was removed percutaneously. Early rethrombosis within 24 hours occurred in five shunts; four more rethrombosed within 2 weeks to 3 months. Eleven shunts were available for follow-up. Cumulative patency was 41% after 6 months. CONCLUSION: Hydrodynamic thrombectomy is a promising concept for declotting of both hemodialysis grafts and native shunts and may offer an alternative to thrombolysis and surgical thrombectomy.     

The ralationship between changes in 5-HT induced platelet aggregation and clinical state in patients treated with fluphenazine

Platelet aggregation responses to 5-HT and adenosine diphosphate were examined in a population of eighteen patients treated with fluphenazine decanoate for longer than one year. 5-HT induced aggregation was enhanced in ten subjects. This enhancement was similar to that previously described in patients receiving chlorpromazine. Patients who showed enhanced 5-HT induced aggregation showed less rateable psychopathology and less extrapyramidal side-effects than patients who did not show enhancement. These findings suggest that platelet aggregation responses could be used to identify patients who could be safely withdrawn from long-term neuroleptic therapy.     

The effect of hydroxyethyl starch on platelet aggregation in vitro

To elucidate the role of endogenous nitric oxide (NO) in allergen- (AIB) and hyperventilation-induced bronchoconstriction (HIB), the effects of an NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), on AIB and HIB were studied in guinea-pigs. In the AIB group, 21 anaesthetized guinea-pigs, actively sensitized with 1% ovalbumin, were challenged with aerosolized 0.1% ovalbumin solution under mechanical ventilation. In the HIB group, 14 guinea-pigs were challenged with hyperventilation (tidal volume of 12 mL x kg(-1) at 150 breaths x min(-1) with 21% O2 and 5% CO2 dry gas) for 5 min. In both groups, lung resistance (RL) was measured using a pressure-volume-sensitive body plethysmograph, with or without L-NAME pretreatment (8 mg x kg(-1) i.v. followed by 2 mg x kg(-1) x min(-1) i.v.). The NO precursor, L-arginine was injected at a rate of 15 mg x kg(-1) x min(-1) after L-NAME injection (10 mg x kg(-1)) in the AIB group. The results were as follows. In the AIB group, the maximal RL change was significantly potentiated by pretreatment with L-NAME. This potentiating effect of L-NAME was reversed by L-arginine. In the HIB group, the pretreatment with L-NAME had no effect on increases in RL. These findings suggest that endogenous nitric oxide may play an important role in the modulation of allergen-, but not hyperventilation-induced bronchoconstriction in guinea-pigs.     

Investigations of platelet aggregation and platelet counts from stored canine whole blood

The effects of the long term storage of canine blood at 4 to 6 degrees C in PVC-bags containing CPDA-1 as a stabiliser on platelet aggregation and platelet counts were investigated. Aggregation induced by collagen, adenosine diphosphate or a calcium ionophore was preserved well during the first six hours, but there was then a decrease of 24 to 46 per cent in the ability of the platelets to aggregate, after which during the next three to four weeks of storage there was no further decrease in their aggregation properties. The formation of aggregates of platelets reduced the numbers of platelets counted as single thrombocytes by more than 30 per cent during the first four days. The numbers of platelets recorded varied widely with the counting method used (counting chamber or automatically) and with the ethylenediamine tetra-acetic acid content of the dilution fluid.     

The measurement of hostility in clinical situations.

"This study attempted to formulate operational definitions for the various meanings of the concept of hostility. Thirty men and thirty women, patients in a neuropsychiatric hospital, were interviewed and rated by three judges for the following aspects of hostility: Resentment, Verbal hostility, Indirect hostility, Assault, Suspicion, Over-all hostility, and Strength of hostile urges. Also, the Iowa Hostility Inventory was administered. It was found that the judges' ratings of the various aspects of hostility showed general agreement." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of histamine in platelet aggregation by physiological and immunological stimuli

This paper reviews the current state of the debate on the relationship between mental disorder and violent behaviour. Starting from the discussion of methodological approaches to assessing a possible association, the most important studies carried out on the issue in recent years are discussed. Their results concur in supporting the assumption that there is a moderate but reliable association between mental disorder and violence. However, this does not imply that people with mental illness are generally more likely to commit violent acts than members of the general population. An elevated risk of violent behaviour is only evident for specific psychiatric diagnoses and for particular symptom constellations. For schizophrenia and other psychotic disorders, a significant increase in the likelihood to commit violent acts is reported. Substance use disorder and antisocial personality disorder, however, represent a markedly higher risk for violent behaviour. The article further discusses possible determinant of violent behaviour such as psychotic symptoms and comorbidity with substance abuse, and considers who is at particular risk of becoming a target of violent acts.     

The release mechanism of platelet-activating factor during shear-stress induced platelet aggregation

Data on polymorphism of the control region of mitochondrial DNA (mtDNA) in Eastern Slavs were analyzed by the median network method. A bimodal distribution of pairwise nucleotide differences between types of the mtDNA control region was revealed; distribution was similar to that found in southern European populations. The nucleotide diversity of mtDNA types in Eastern Slavs corresponded to an evolutionary age of 10-40 thousand years. Characteristics of the mitochondrial portrait of Eastern Slavs are discussed in terms of formation of the European population in Neolith.     

Effects of insulin on calcium metabolism and platelet aggregation

Poppy seeds from seven different origins (Dutch, Australian, Hungarian, Spanish, Czech, and two Turkish) were analyzed for the amount of opiates present. Four grams of each kind of seeds, equivalent to the amount of seeds on two bagels, were ingested by volunteers. One volunteer also ingested four times the same amount of poppy seeds from the same origin (Spanish). During 24 hours urine samples were obtained and screened for the presence of morphine and codeine using the FPIA technique (cut-off = 200 ng/mL) and a GC/MS confirmation with a limit of detection (LOD) of 25 ng/mL for codeine and morphine. Poppy seeds from different origins contain a wide variation of morphine (2-251 micro g/g) and codeine (0.4-57.1 micro g/g) content. No other opiate could be detected. After ingestion a large interindividual variation of excretion of opiates exists. The testing results from the same kind of seeds ingested four times with a one week interval by the same volunteer also show a poor reproduceability. Several kinds of poppy seeds can give positive testing results (Australian, Hungarian, Spanish and one kind of Turkish seeds). Within 24 hours all testing results became negative.     

The stimulation of neoangiogenesis in the ischemic human heart by the growth factor FGF: first clinical results

AtFKBP12 is an Arabidopsis cDNA that encodes a protein similar to the mammalian immunophilin, FKBP12. AtFKBP12 was used as 'bait' in a yeast 2-hybrid system to screen for cDNAs in Arabidopsis encoding proteins that bind to FKBP12. Two partial cDNAs were recovered encoding the C-terminus of a protein we have called Arabidopsis thaliana FKBP12 interacting protein 37 (AtFIP37). AtFIP37 is similar to a mammalian protein, FAP48, that also binds to FKBP12. The interaction between AtFKBP12 and AtFIP37 in the 2-hybrid system, as assessed by histidine auxotrophy and beta-galactosidase activity, was disrupted by FK506, but not by cyclosporin A, a drug that binds to cyclophilin A. AtFIP37 was also shown to bind in vitro to AtFKBP12 in GST-fusion protein binding assays. The binding was abolished by prior incubation of AtFKBP12 with FK506. These findings indicate that an Arabidopsis FKBP12 ortholog encodes a protein that binds FK506 and that the interaction between AtFKBP12 and AtFIP37 may involve the FK506 binding site of AtFKBP12. The interaction provides interesting new opportunities for controlling protein:protein interactions in vivo in plants.