Heart rate and systolic blood pressure in patients with persistent atrial fibrillation. A linguistic analysis.

BACKGROUND: During atrial fibrillation (AF), ventricular response is highly irregular and thus the beat-to-beat variation of blood pressure is increased because of variations in filling time and in contractility. OBJECTIVES: Aim of the present study is to investigate the short-term dynamics of RR and SAP series in patients with AF, during rest and tilt, and after restoration of sinus rhythm. METHODS: We computed symbolic sequences of the three phases, as they retain important features of the dynamics generated by the underlying control system. Then we applied a method based on rank order statistics of symbolic sequences to investigate the profile of different types of dynamics. The linguistic distance (range 0-1) between sequences represents a measure of similarity to assess whether the different physiological states are reflected on the dynamics of RR and SAP series. RESULTS: The distance between rest and tilt phases is 0.06 ± 0.02 for RR series, meaning they are very similar, while it is 0.21 ± 0.13 for SAP series, showing a difference in the short-term dynamics. RR mean decreases during tilt (738 ± 164 vs. 692 ± 152 ms, p <0.05, rest vs. tilt), while mean SAP is not significantly different (101 ± 20 vs. 104 ± 14 mmHg, rest vs. tilt). Comparing AF and sinus rhythm, both RR and SAP series result different in terms of the computed distance. CONCLUSIONS: SAP short-term dynamics seem to significantly change when comparing rest and tilt phases, while RR series remain unchanged. Moreover, RR mean but not SAP series significantly decreases during tilt.

Analysis of living cells grown on different titanium surfaces by time-lapse confocal microscopy.

In this study we have combined fluorescence- and reflection-confocal laser scanning microscopy for the simultaneous visualization of living cells and surface topography beneath them. To this purpose we have designed a specific flow chamber and we have tested it with osteoblasts grown on an opaque, thick support, made of smooth or sandblasted titanium. Cells were loaded with Calcein-AM or tetramethylrhodamine methyl ester (TMRM), two probes employed as indicators of cell viability/morphology and mitochondrial membrane potential, respectively. Besides the acquisition of stacks of confocal sections, the system allowed also vertical views and faithful three-dimensional reconstruction of the samples. Confocal microscope implemented with our flow chamber proved to be a promising tool for time-lapse investigation of cell-biomaterial interactions.

Parasuicide in Rovigo (North of Italy) during the period 2000-2005.

INTRODUCTION: The greatest predictor of eventual suicide is parasuicide, which includes both suicide attempts and deliberate self-harm with no intent to die. The rate of parasuicide is reckoned to be at least ten times the suicide rate. METHODS: An observational study of the population of Rovigo Public Health Unit has been carried out to investigate parasuicide cases that presented to a general hospital in the six-year period from 1st January 2000 to 31st December 2005. RESULTS: An incidence of 36.39 parasuicides/100,000/year referred to a general hospital has been estimated, with a majority of female and young subjects. The principal method used was drug poisoning (59.1%); the more frequent diagnoses are mood and personality disorders. Method of attempt distribution is different for age and gender (p < 0.001), while diagnosis distribution is different only for age (p < 0.001). Comparison between method of attempt and diagnosis distribution indicates a significant difference (p < 0.01). In 36.4% of cases there was no contact with the Mental Health Service after parasuicide. DISCUSSION: The present study confirms that parasuicide is more common in females and younger people and that the more probable diagnoses are mood and personality disorders. The finding of a high number of subjects without any previous contact with the Mental Health Service and, especially, after parasuicide, claims attention on primary and secondary prevention of suicidal behaviour. CONCLUSIONS: The results appear to be in line with those from literature on parasuicide in Western populations.

Effects of cardioversion of atrial fibrillation on endothelial function in hypertension or diabetes.

BACKGROUND: Cardioversion (CV) to sinus rhythm corrects endothelial dysfunction secondary to atrial fibrillation (AF). As AF often complicates hypertension and diabetes (disorders associated with impaired endothelial function) the study probed whether these comorbidities to AF produced an additive effect and to what extent CV might be advantageous. MATERIALS AND METHODS: Brachial artery flow-mediated dilatation (FMD) was evaluated before and after CV in 17 lone AF patients (group 1), 16 patients with AF + hypertension (group 2) and 17 patients with AF + diabetes type II (group 3), while in supine and head-up tilting (HUT) positions, as this is when endothelial vasodilation is emphasized as a counterbalance to neurogenic vasoconstriction. RESULTS: After 2 weeks, CV in group 1 increased (P < 0.01) supine FMD (from 7.22-->9.50%) and restored its HUT potentiation (from 9.31-->17.22%). In group 2, FMD also improved significantly with CV (supine from 4.92-->7.11% and HUT from 5.29-->11.83%; P < 0.01). In group 3, CV did not promote significant FMD changes (supine from 5.12-->4.92% and HUT from 4.98-->4.73%). After 3 months, FMD improvement persisted in groups 1 and 2 with enduring sinus rhythm, but not in those with AF relapse. In group 3, FMD remained unchanged regardless of cardiac rhythm. CONCLUSIONS: Cardioversion persistently increases supine shear stress endothelial responsiveness and restores the orthostatic modulation in AF alone or in association with hypertension, but not with diabetes. Differences in background endothelial impairment may explain the presence (hypertension) or the absence (diabetes) of an additive AF effect in comorbidities, as well as CV results.

[The approach to the infradiaphragmatic and adrenal aorta]. / Vie di accesso all'aorta pararenale e sottodiaframmatica.

The progressive selection of the patient reserved to open surgery is determined by the preference of the endovascular option on the treatment of abdominal aortic aneurysm. This fact probably will cause a reduction of the number of cases singularly approachable by the infrarenal way while will prevail the need of control and clamping of the infradiaphragmatic and adrenal aorta. The approach to the infradiaphragmatic and adrenal aorta introduces technical and physiopathologic problems related to the hold interconnection between the vessel and the surrounding structures, particularly those visceral. The choice of the approach is determined by the surgical gesture that is had to perform. The simple supraceliac aortic clamping or the wrapping of bypass on the visceral arteries can be made by an anterior approach, supramesocolic transperitoneal, while the correction of an juxtarenal or adrenal aneurysm can be performed by a submesocolic approach. The extraperitoneal approach offers a complete vision of this part of aorta, without the pancreas or left renal veins interposition, but it allows a bad control of the iliac and right renal arteries. The surgeon has to have familiarity with both the approaches, to be able to perform his own intervention in the simplest and effective way.

[The autonomic nervous system in myocardial infarction]. / Il sistema nervoso autonomo nell'infarto miocardico.

The occurrence of alterations in the autonomic control of cardiovascular function has long been known. Nevertheless, only in the last 15 years with the development and utilization of techniques such as heart rate variability and baroreflex analysis, unforeseeable amounts of information have been collected. The appraisal of alterations in the autonomic control mechanisms in the acute and post-acute phase of myocardial infarction has not only confirmed the presence of an increased sympathetic and of a reduced vagal modulation in most of post-myocardial infarction patients. It has also allowed the clinically relevant identification of those patients with an increased arrhythmic and total cardiac mortality. Most the high-risk patients are indeed characterized by a marked reduction in heart rate variability that can be detected using different methodologies. For example, with time-domain analysis of heart rate variability, it has been shown that an SDNN < 70 ms identifies patients at risk. By using spectral analysis, it has been possible to realize that the loss or marked attenuation of those rhythmical components that reflect autonomic modulation is also a characteristic of the high-risk patients. A decreased responsiveness of the sinus node to autonomic inputs may also explain the reduction in baroreflex sensitivity that characterizes patients with an increased arrhythmic mortality. In conclusion, the appraisal in each patient of the extent of the alterations in the autonomic control mechanism is nowadays a critical component of the clinical assessment not only for risk stratification but also in order to guide the prescription of new pharmacological and non-pharmacological therapies.

Autosomal dominant macrothrombocytopenia in Italy is most frequently a type of heterozygous Bernard-Soulier syndrome.

A form of autosomal dominant macrothrombocytopenia is characterized by mild or no clinical symptoms, normal platelet function, and normal megakaryocyte count. Because this condition has so far received little attention, patients are subject to misdiagnosis and inappropriate therapy. To identify the molecular basis of this disease, 12 Italian families were studied by linkage analysis and mutation screening. Flow cytometry evaluations of platelet membrane glycoproteins (GPs) were also performed. Linkage analysis in 2 large families localized the gene to chromosome 17p, in an interval containing an excellent candidate, the GPIbalpha gene. GPIbalpha, together with other proteins, constitutes the plasma von Willebrand factor (vWF) receptor, which is altered in Bernard-Soulier syndrome (BSS). In 6 of 12 families, a heterozygous Ala156Val missense substitution was identified. Platelet membrane GP studies were performed in 10 patients. Eight were distinguished by a reduction of GPs comparable to that found in a BSS heterozygous condition, whereas the other 2, without the Ala156Val mutation, had a normal content of platelet GPs. In conclusion, the current study provides evidence that most (10 of 12) patients with an original diagnosis of autosomal dominant macrothrombocytopenia shared clinical and molecular features with the heterozygous BSS phenotype. The remaining 2 affected subjects represented patients with "true" autosomal dominant macrothrombocytopenia; the GPIb/IX/V complex was normally distributed on the surface of their platelets. Thus, the diagnosis of heterozygous BSS must always be suspected in patients with inherited thrombocytopenia and platelet macrocytosis.

Mutations in MYH9 result in the May-Hegglin anomaly, and Fechtner and Sebastian syndromes. The May-Heggllin/Fechtner Syndrome Consortium.

The autosomal dominant, giant-platelet disorders, May-Hegglin anomaly (MHA; MIM 155100), Fechtner syndrome (FTNS; MIM 153640) and Sebastian syndrome (SBS), share the triad of thrombocytopenia, large platelets and characteristic leukocyte inclusions ('Döhle-like' bodies). MHA and SBS can be differentiated by subtle ultrastructural leukocyte inclusion features, whereas FTNS is distinguished by the additional Alport-like clinical features of sensorineural deafness, cataracts and nephritis. The similarities between these platelet disorders and our recent refinement of the MHA (ref. 6) and FTNS (ref. 7) disease loci to an overlapping region of 480 kb on chromosome 22 suggested that all three disorders are allelic. Among the identified candidate genes is the gene encoding nonmuscle myosin heavy chain 9 (MYH9; refs 8-10), which is expressed in platelets and upregulated during granulocyte differentiation. We identified six MYH9 mutations (one nonsense and five missense) in seven unrelated probands from MHA, SBS and FTNS families. On the basis of molecular modelling, the two mutations affecting the myosin head were predicted to impose electrostatic and conformational changes, whereas the truncating mutation deleted the unique carboxy-terminal tailpiece. The remaining missense mutations, all affecting highly conserved coiled-coil domain positions, imparted destabilizing electrostatic and polar changes. Thus, our results suggest that mutations in MYH9 result in three megakaryocyte/platelet/leukocyte syndromes and are important in the pathogenesis of sensorineural deafness, cataracts and nephritis.

Transfusion of platelet concentrates cryopreserved with ThromboSol plus low-dose dimethylsulphoxide in patients with severe thrombocytopenia: a pilot study.

We have recently reported the possibility of supporting the phase of severe thrombocytopenia after high-dose chemotherapy (HDC) and stem cell transplantation using 5% dimethylsulphoxide (DMSO)-cryopreserved autologous platelet concentrates (PCs). The aim of the present study was to evaluate the therapeutic potential of ThromboSol (a recently developed platelet storage solution) plus PCs cryopreserved in 2% DMSO in patients undergoing myeloablative chemotherapy and autologous transplantation. PCs were collected from 14 women with breast cancer by a single plateletapheresis and cryopreserved in ThromboSol/2% DMSO by either direct insertion in a -80 degrees C freezer or in liquid nitrogen after computer-controlled rate (CR) freezing. When required, PCs were thawed, centrifuged to remove the cryoprotectants and transfused. In vitro studies on thawed platelets showed loss of epitopes of surface glycoproteins and a marked reduction of functional activity compared with fresh platelets. Transfusion of CR-frozen PCs was associated with a mean 1 h corrected count increment (CCI) of 9.2 +/- 5.4 x 109/l and only one allogeneic PC was required in this group. In contrast, six out of seven patients required additional allogeneic transfusions in the -80 degrees C group (CCI = 2.7 +/- 1.4 x 109/l). ThromboSol-treated PCs have the ability to overcome thrombocytopenia if processed by a CR freezing protocol, but appear ineffective when frozen by direct placing at -80 degrees C.

In vitro and in vivo effects of desmopressin on platelet function.

BACKGROUND AND OBJECTIVE: Desmopressin (DDAVP) may shorten bleeding time in patients with disorders of platelet function, but its mechanism of action in these conditions is still a matter of debate. In particular, contrasting results have been obtained concerning the ability of DDAVP to interact with platelets and to activate them directly. To gain further information on the DDAVP-platelet interaction, we studied the in vitro and ex vivo effects of DDAVP on platelet function. DESIGN AND METHODS: Platelet responses to DDAVP both as a single agent and in conjunction with agonists of platelet activation were investigated. For in vitro experiments platelets were obtained from healthy adult volunteers, while the ex vivo effects of DDAVP were studied in 12 patients with a bleeding disorder receiving a test dose of this drug. RESULTS: DDAVP in vitro did not induce either platelet aggregation or surface expression of the activation-dependent antigens; it did, however, greatly inhibit platelet aggregation response to vasopressin (AVP) and increased the maximal extent of platelet aggregation induced by collagen and ADP. DDAVP infusion did not promote the expression of activation antigens, but significantly enhanced ex vivo platelet aggregation stimulated by ADP and collagen. This priming effect was observed in patients with von Willebrand's disease, hemophilia A, May-Hegglin anomaly, gray platelet syndrome and Ehlers-Danlos syndrome. In all these patients bleeding time was shortened by DDAVP infusion. In contrast, neither platelet aggregation nor bleeding time was modified in two subjects with Glanzmann's thrombasthenia. INTERPRETATION AND CONCLUSIONS: Our in vitro experiments indicate that DDAVP interacts directly with platelets and facilitates their activation via other agonists. In vivo results suggest that this effect occurs and is clinically relevant in patients with platelet dysfunction responding to DDAVP with a shortening of bleeding time.

Incompatibility for CD31 and human platelet antigens and acute graft-versus-host disease after bone marrow transplantation.

Bone marrow transplantation (BMT) is often complicated by acute graft-versus-host disease (aGVHD). In patients transplanted with an HLA-matched donor the occurrence of this complication is believed to be favoured by disparities at the minor histocompatibility antigens (mHA). However, few of these polymorphic molecules have been identified. We sought to determine whether donor/recipient incompatibility for HPA-1, HPA-2, HPA-3, HPA-5 or CD31 (codon 125) antigens represented a risk factor for aGVHD and genotyped these antigens in 70 bone marrow donors and their HLA-identical recipients. All patients were children who received BMT for haematological malignancies at a single institution according to well-defined therapy protocols. Statistical analysis showed that incompatibility for CD31 (codon 125) was a risk factor for grade II-IV aGVHD in the overall patient population, whereas HPA-3 incompatibility predicted aGVHD occurrence in HLA-A2 patients only. The magnitude of the aGVHD risk was directly related to the number of HPA/CD31 incompatibilities. No correlation was found between non-identity for HPA/CD31 and aGVHD. Since incompatibility but not non-identity for CD31 or HPA-3 was a risk factor for aGVHD, we suggest that allelic variants of these molecules can serve as mHA in BMT recipients from HLA-identical donors.

Relationship between size and thiazole orange fluorescence of platelets in patients undergoing high-dose chemotherapy.

The reticulated platelet count relies upon the assumption that newly formed platelets contain a residual amount of RNA which selectively binds the dye thiazole orange (TO) and greatly enhances its fluorescence signal. It has, however, recently been shown that almost half of the platelet TO-signal is derived from the labelling of dense-granule nucleotides. It is therefore possible that the higher TO fluorescence of young platelets partially derives from the higher granule content due to their larger volume. To investigate the relationship between platelet size and TO fluorescence we studied 13 patients with high-risk breast cancer undergoing high-dose chemotherapy. Mean platelet volume, platelet distribution width, platelet-large cell ratio, membrane content of glycoprotein Ib and IIb-IIIa and platelet aggregation were significantly greater during resolution than during development of thrombocytopenia, suggesting a prevalence of young and old platelets respectively. Mean TO fluorescence per cell was higher in the platelet population enriched in young cells than in that enriched in old cells, but this difference was no longer observed when the ratio TO signal/platelet size was examined. Moreover, RNase treatment and platelet degranulation reduced TO fluorescence to a similar extent in platelet populations enriched in young or old cells. Therefore our data suggest that the higher TO signal of young platelets is derived, to a significant extent, from their larger volume and granule content.

An in vitro model for the assessment of manganese neurotoxicity.

PC12 (undifferentiated and differentiated) and C6 cells have been used to investigate kinetics, morphological and functional endpoints following exposure to MnCl(2) and manganic transferrin (Mn-Tf). [Mn](i) in undifferentiated (non-differentiated cells) exposed to both free (MnCl(2)) and bound Mn (Mn-Tf), was three- to fivefold lower as compared to differentiated (differentiated) PC12 cells and higher by one order of magnitude as compared to glial C6 cells. Exposure to both MnCl(2) and Mn-Tf was followed by time- and dose-dependent morphological changes characteristic of apoptosis, which was never observed in Mn-exposed C6 glial cells. Results from cell viability assays were consistent with apoptotic response rates quantified by cell count. Threshold concentrations for undifferentiated and differentiated PC12 cells were 10(-6) and 10(-5)m, respectively. Thus, despite their greater ability to accumulate Mn, differentiated PC12 cells are less sensitive to Mn-induced apoptosis. This model might be relevant to neuronal degeneration induced by Mn occurring in the developing brain and possibly in clinical manganism. Such critical doses at the cellular level seem to be consistent with Mn levels (5x10(-6)m) recorded in the basal ganglia of monkeys chronically exposed to Mn and developing clinical signs of manganism.

Early assessment of viable myocardium after acute myocardial infarction by low-dose echo-dobutamine.

BACKGROUND: The aim of the study was to evaluate the usefulness of low-dose dobutamine echocardiographic testing performed within 48 hours from anterior AMI in order to identify the extent of viable myocardium and predict its functional outcome. The early echo-dobutamine test was also compared with a predischarge test in order to evaluate the effects of different timing on the accuracy of the test. METHODS: Nineteen consecutive patients, aged 54 +/- 11 years, with a first anterior AMI entered the study. All patients underwent a low-dose dobutamine echocardiographic test within 48 hours from hospital admission and at predischarge. In all the patients, a rest follow-up echocardiogram was performed three months after hospital discharge. Eleven patients underwent a revascularization procedure (7 underwent PTCA and 4 CABG). RESULTS: Of the 159 dyssynergic segments, 26% improved spontaneously at predischarge and 51% improved at the three-month follow-up. Of the 145 predischarge dyssynergic segments, 38% improved at three months. Considering the results on a segmental basis, early low-dose dobutamine echocardiography showed a sensitivity of 52%, a specificity of 87%, a positive predictive value of 81%, a negative predictive value of 64% and a diagnostic accuracy of 69% for wall-motion improvement at three months. The predischarge test showed very similar values. A slight enhancement of the sensitivity of both tests was observed considering the akinetic segments only. Finally, considering the amount of segmental reversible dysfunction inside the infarct area in the single patients, early low-dose dobutamine echocardiography showed a sensitivity of 86% and a specificity of 80%. CONCLUSIONS: Our results indicate that: 1) recovery of regional wall motion after AMI is slow and progressive, with substantial improvement ensuing within the first days after infarction; 2) considering results on a segmental basis, low-dose dobutamine echocardiography performed within 48 hours of AMI shows a high specificity but a low sensitivity for late recovery of regional function, although it gave information similar to what was obtained performing the test at predischarge; 3) the efficiency of test can be improved by considering the amount of reversible segmental dysfunction inside the infarct area in the single patients.

Comparison of annexin V and calcein-AM as early vital markers of apoptosis in adherent cells by confocal laser microscopy.

Although morphological criteria for apoptosis are in general reliable, no systematic comparison of the techniques employed thus far has yet been performed. In this study, using confocal laser microscopy, we compared the performance of annexin V-FITC and calcein-AM for early detection of apoptosis in living adherent cells. Experiments were carried out on two distinct cell lines, PC 12 and NIH3T3, endowed with different shape and adhesion properties. The apoptotic process was followed for a prolonged period in the same cells of a predetermined field by means of a special flow chamber. Our results show that both probes allowed the detection of apoptotic cells in either cell line. However, some cells that clearly exhibited apoptotic changes on calcein visualization were annexin-negative. In NIH3T3 cells, annexin negativity of apoptotic cells was correlated with the preservation of cell shape and adhesion properties. These findings show that, at least in PC12 and NIH3T3 cells, annexin might be less sensitive than calcein-AM for early apoptosis detection and, for NIH3T3 cells, suggest that phosphatidilserine exposure is in some way linked to changes in cell shape and/or adhesion to culture substrate. (J Histochem Cytochem 46:895-900, 1998)

Thrombocytopenia, giant platelets, and leukocyte inclusion bodies (May-Hegglin anomaly): clinical and laboratory findings.

PURPOSE: May-Hegglin anomaly is a rare hereditary condition characterized by the triad of thrombocytopenia, giant platelets, and inclusion bodies in leukocytes. Clinical features and the pathogenesis of bleeding in this disease are poorly defined. PATIENTS AND METHODS: From 1988 to 1996 we studied 15 new May-Hegglin anomaly patients from 7 unrelated Italian families. In addition to clinical examination and routine laboratory testing, we measured bleeding time, platelet aggregation and release reaction, and platelet staining for tubulin, and performed ultrastructural study of polymorphonuclear leukocytes. RESULTS: Although the mean age of our patients was 33 years, May-Hegglin anomaly had not been previously recognized in any of them. Bleeding diatheses ranged from severe to absent, and platelet count from 26 to 178 x 10(9)/L. No correlation was found between bleeding tendency and platelet count. Previous therapy with corticosteroids, high-dose immunoglobulins, and splenectomy had no effect on platelet count or bleeding diathesis. Desmopressin infusion greatly shortened the bleeding time in the most severely affected patient. The in vitro function of platelets was normal except for the absence of shape change in all subjects and defective response to epinephrine in 8 of 15 patients. Platelet tubulin was distributed unevenly instead of being organized in a circumferential band at the cell periphery. CONCLUSION: The diagnosis of May-Hegglin is easily missed, and its frequency is probably underestimated. A qualitative defect of platelets may be responsible for mild bleeding diathesis even in the absence of thrombocytopenia, while severe bleeding results from both qualitative and quantitative platelet defects. May-Hegglin anomaly should be suspected whenever a patient has a low platelet count or a bleeding diathesis of unknown origin.

A new variant of Bernard-Soulier syndrome characterized by dysfunctional glycoprotein (GP) Ib and severely reduced amounts of GPIX and GPV.

We describe a new variant of Bernard-Soulier syndrome characterized by almost normal amounts of GPIb and severely reduced GPIX and GPV. Despite surface expression, GPIbalpha failed to support ristocetin-induced platelet agglutination and to bind two conformation-dependent monoclonal antibodies, suggesting a qualitative defect. Sequence analysis of the gene coding for GPIX revealed a T-to-C substitution at base 1811, leading to a Leu40Pro conversion, whereas no defects were found in the coding region of the GPIbalpha gene. Allele-specific restriction enzyme analysis showed that the propositus and one of his sisters. both with severe bleeding diathesis. were homozygous for the GPIX mutation: the members of the family with mild bleeding diathesis and/or giant platelets in the peripheral blood were heterozygous, whereas the healthy ones were homozygous for the normal allele. Infusion of 1-desamino-8-D-arginine vasopressin normalized bleeding time in the two severely affected patients, although it did not modify ristocetin-induced platelet agglutination or membrane expression of GPIbalpha, GPIX, GPIIb-IIIa and GMP-140. Moreover, in one patient, normalization of bleeding time and rise of von Willebrand factor plasma concentration did not seem to be directly related.