Calcium-binding sites of the thrombin-thrombomodulin-protein C complex: possible implications for the effect of platelet factor 4 on the activation of vitamin K-dependent coagulation factors

The Ca(2+)-dependence of protein C activation by thrombin in complex with thrombomodulin (TM) containing chondroitin sulfate (CS) exhibits saturation at approximately 0.5-1 mM Ca(2+), but with TM lacking CS, it has a distinct optimum at approximately 0.1 mM Ca(2+). Since the substrate protein C has multiple Ca(2+)-binding sites, and the cofactor TM also interacts with Ca(2+), the basis for differences in Ca(2+) effect on protein C activation by thrombin in complex with TM containing or lacking CS is not known. In this study, by using full-length and Gla-domainless mutants of protein C whose activation by thrombin is independent of either Ca(2+) or both Ca(2+) and TM, we demonstrate that i) the Ca(2+) occupancy of a high-affinity binding site in TM is essential for the high-affinity interaction of the cofactor with thrombin, ii) the Ca(2+) occupancy of a binding site (K(D) approximately 50 microM) in the catalytic domain of protein C is required for the substrate recognition by the thrombin-TM complex, however, at this concentration of Ca(2+) the Gla domain of protein C is not folded properly and thus interacts with exosite-2 of thrombin in complex with TM that lacks CS but not with TM that contains CS, and finally iii) platelet factor 4 can nonspecifically interact with the Gla domain of protein C and other coagulation factors to influence their activation only at subphysiological concentrations of Ca(2+).     

Non-functioning pituitary adenoma: immunohistochemical analysis of 85 cases

Pituitary adenomas without clinically active hypersecretion are summarized under the term non-functioning pituitary adenoma (NFPA). Since there are no specific serum markers, the differential diagnosis and treatment imply special difficulties. By using immunohistochemical methods we will have new insight into the nature and pathogenesis of these tumours. Ki-67 is a nuclear antigen detected by the monoclonal antibody MIB-1 and its labelling index (LI) is considered a marker of normal and abnormal cell proliferation. The aim of this study was to investigate the possible role of immunohistochemistry and MIB1-LI determination in NFPAs to predict tumoural behaviour and better management. In this clinicopathological study, 85 cases of NFPAs were analysed immunohistochemically. MIB1-LI was also determined in studied cases. Clinical presentation, treatment and follow-up data were also reviewed and the correlation between clinical and pathologic findings was established. Eighteen adenomas (21.2%) were immunoreactive to one or two adenohypophysial hormones of which 4 GH positive adenomas had aggressive behaviour (2 significant juxtasellar extensions and 2 recurrences). MIB-1 LI was more than 5% in only 5 cases including 2 invasive adenomas but with no evidence of recurrence. No significant statistical difference between clinical presentations in immunoreactive and non-immunoreactive NFPAs was observed except for unilateral temporal hemianopia which was more common in immunoreactive adenomas (P=0.022). NFPAs comprise several pathologically different types of tumours, some of which are potentially hormone producing, but some defects in hormone secretion or production of biologically inactive or insufficient amount of hormone may be the culprit in the lack of evidence of rising serum hormone levels. MIB-1 LI may be indicative of invasiveness but not a predictor of recurrence. Silent somatotropinomas may have more aggressive behaviour in comparison with other NFPAs.     

Periodontopathic bacteria and herpesviruses in chronic periodontitis

Periodontal disease involves complex interactions of microorganisms and host defenses. This work investigated the associations between putative bacterial pathogens, herpesviruses and chronic periodontitis. Subgingival samples were collected from 40 periodontally healthy individuals and from 40 patients with chronic periodontitis with probing depths of ≤3 mm or ≥6 mm. Multiplex and nested polymerase chain reactions were used to identify bacterial pathogens and herpesviruses. Porphyromonas gingivalis, Tannerella forsythia, Epstein–Barr virus (EBV) type 1, cytomegalovirus (CMV), Aggregatibacter actinomycetemcomitans and EBV type 2 were detected in, respectively, 95, 75, 72.5, 50, 12.5 and 10% of sites with probing depths ≥6 mm. P. gingivalis, T. forsythia, EBV‐1 and CMV were statistically associated with probing depths ≥6 mm. A. actinomycetemcomitans and EBV‐2 showed no association with periodontitis sites, and no significant associations were found for any of the test infectious agents and probing depths ≤3 mm. Our results confirm an association between P. gingivalis, T. forsythia, EBV‐1 and CMV, and chronic periodontitis. These infectious agents may play an important synergistic role in the pathogenesis of chronic periodontitis.     

Pain affects health-related quality of life in kidney transplant recipients

BACKGROUND: Chronic pain is prevalent in end-stage renal disease patients undergoing chronic hemodialysis. We do not fully know the intensity of chronic pain experienced by kidney recipients in comparison to those on chronic hemodialysis and healthy controls. Moreover, the effect of chronic pain on kidney recipients' health-related quality of life (HRQoL) is yet to be comprehensively addressed. We designed this study to find an answer to these questions. METHODS: In this case control study, we studied 205 kidney recipients, 69 hemodialysis patients, and 100 healthy controls, who were matched for age, sex, monthly family income, and educational level. The patients were evaluated for the intensity of chronic pain by Visual Analogue Scale (VAS). HRQoL was measured with Short Form 36 (SF-36) in the kidney recipients. Chronic pain intensity was compared in the study groups, and in the kidney recipients the correlation between SF-36 subscores and severity of pain was assessed. RESULTS: Severity of pain in the kidney recipients was lower than the hemodialysis patients, but more than the healthy controls (P=.001). The VAS pain score negatively correlated with the scores of SF- 36 total (r=-.329, P=01), mental health (r=-.190, P=07), physical health (r=-.275, P=.001), physical function (r=-.339, P=.001), role limitation due to physical problems (r=-.478, P=.001), role limitation due to emotional problems (r=-.326, P=.001), and bodily pain (r=-.894, P=.001). DISCUSSION: The intensity of chronic pain experienced by the kidney recipients is less than that experienced by patients under chronic hemodialysis, but higher than healthy subjects. Focusing on chronic pain as a cause of post-renal transplantation morbidity is expected to improve post-renal transplantation quality of life.     

Synaptic lesions and synaptophysin distribution change in spinal motoneurons at early stages following sciatic nerve transection in neonatal rats

The purpose of this investigation was to evaluate the rate of synaptic stripping, changes in the synaptophysin distribution, and synapses ultrastructure of spinal motoneurons at early stages of sciatic nerve axotomy in newborn rats. Seven groups were used in the experiment, which were sacrificed after 1, 3, 6, 12, 24, 48 and 72 h. L4-L6 spinal segments from the animals of the above groups were prepared and processed for indirect immunoperoxidase. Accordingly, tissue samples were prepared from similar groups for routine electron microscopy. Synaptophysin-labeled motoneurons were classified into intact, partial, cytoplasmic and negative patterns. Synaptophysin immunoreactivity in both the axotomized and non-axotomized sides showed no negative pattern at the first three time points, while this pattern significantly increased in the 12, 24, 48 and 72 h groups at the axotomized side, moreover, there was a progressive reduction in the percentage of the intact pattern at the axotomized side. The percentages of the cytoplasmic and partial patterns also increased during the time course. The rate of synaptic stripping was five time higher in the axotomized side than that of non-axotomized side. The results of the ultrastructural study showed synaptic membranes irregularity, synaptic vesicles displacement, synaptic membrane detachment and ensheathment of degenerated synapses. The conclusion of the study was that early synaptophysin immunoreactivity changes were seen in both the axotomized and non-axotomized sides, but the rate of change in the axotomized side was more rapid than that of the non-axotomized side.     

Event-related potential characterisation of the Shakespearean functional shift in narrative sentence structure

Neurolinguistic studies have scrutinised the physiological consequences of disruptions in the flow of language comprehension produced by violations of meaning, syntax, or both. Some 400 years ago, Shakespeare already crafted verses in which the functional status of words was changed, as in "to lip a wanton in a secure couch". Here, we tested the effect of word class conversion as used by Shakespeare--the functional shift--on event-related brain potential waves traditionally reported in neurophysiolinguistics: the left anterior negativity (LAN), the N400, and the P600. Participants made meaningfulness decisions to sentences containing (a) a semantic incongruity, (b) a functional shift, (c) a double violation, or (d) neither a semantic incongruity nor a syntactic violation. The Shakespearean functional shift elicited significant LAN and P600 modulations but failed to modulate the N400 wave. This provides evidence that words which had their functional status changed triggered both an early syntactic evaluation process thought to be mainly automatic and a delayed re-evaluation/repair process that is more controlled, but semantic integration required no additional processing. We propose that this dissociation between syntactic and semantic evaluation enabled Shakespeare to create dramatic effects without diverting his public away from meaning.     

Sensory modulation intervention and behaviour support modification for the treatment of severe aggression in Huntington's disease. A single case experimental design

Aggression is common in Huntington's disease. However, at present there are no standard guidelines for managing aggression in Huntington's sufferers due to a lack of empirical research. This paper presents a case study of the treatment of very high levels of aggression with sensory modulation and behaviour support intervention in a Huntington's sufferer. The client exhibited a range of aggressive behaviours, including physical aggression to people, furniture and objects, and verbal aggression. Following an eight week baseline phase, five weeks of sensory modulation intervention were employed. A behaviour support plan was then implemented as an adjunct to the sensory intervention, with aggressive behaviour systematically audited for a further 11 weeks. The results indicate a significant reduction in reported levels of aggression during the combined sensory modulation and behaviour support phase, compared to both the baseline and the sensory modulation therapy alone phases. This case study highlights the efficacy non-pharmacological interventions may have for reducing aggression in HD.     

Genotyping of clinical and environmental Aspergillus flavus isolates from Iran using microsatellites

Aspergillus flavus is the second most important Aspergillus species causing human infections in tropical countries. Despite an increasing number of infections of A. flavus in Iran, the molecular epidemiology of clinical and environmental strains has not been well studied. We used a panel of nine microsatellite markers to analyse the genetic relatedness of A. flavus. Microsatellite typing of 143 (n = 119 clinical and n = 24 environmental) isolates demonstrated 118 different genotypes. A possible outbreak at a pulmonary ward was discovered. The discriminatory power for the individual markers ranged from 0.4812 to 0.9457 and the panel of all nine markers combined yielded a diversity index of 0.9948. This high‐resolution typing method assists in better understanding of the molecular epidemiology of A. flavus.