Evidence of prolonged disturbances in the haemostatic, hemorheologic and inflammatory profiles in transmural myocardial infarction survivors

Haemostatic, hemorheologic and inflammatory disturbances have been associated with acute coronary syndromes. Most knowledge is reported in cross sectional studies and are without time dependent evolution of these profiles. The aim of this study was to evaluate, during the first year, the evolution of the haemostatic, hemorheologic and inflammatory profiles determined at hospital discharge in survivors with transmural myocardial infarction (MI). Eighty eight (79 male; 9 female) mean age of 58 +/- 11 years, survivors of a transmural MI were prospectively studied at discharge, 6 months and one year after the event. Haemostatic (protein C, antithrombin III and plasminogen activator inhibitor 1), hemorheologic (blood fluidity and components) and inflammatory profiles (polymorphonuclear elastase and leukocyte count) were determined using standard methodology. The results of the study can be summarized as follows: (1) Protein C decreased (p < 0.05) over time while PAI-1 only varied significantly until 6(th) month. (2) Plasma viscosity and fibrinogen (p < 0.001) decrease over time, while erythrocyte aggregation (p < 0.001) and haematocrit increased. Whole blood viscosity did not vary. (3) Leukocyte decreased (p < 0.001) and elastase did not (4). Those patients with cardiovascular events (n = 7) had higher PAI-1 concentration (p < 0.05) and leukocyte count (p < 0.01), at discharge (5) Left ventricle ejection fraction correlated significantly with plasma viscosity (r = 0.35 p < 0.05). The results of this longitudinal study show dynamic modifications of the haemostatic, hemorheologic and inflammatory profiles during the first year of a transmural myocardial infarction. In addition, there are interrelations between them and the clinical profile that could help to explain the clinical evolution of this group of patients.

Long-term prognostic value of the hemorheological profile in transmural myocardial infarction survivors: 60-month clinical follow-up

Previous reports have shown several hemorheological and hemostatic abnormalities in acute coronary syndrome survivors. Some of these abnormalities were related to cardiovascular events during a 24-month follow-up. The aim of the present work is to evaluate, in transmural myocardial infarction survivors, the long-term (60 months) prognostic value of the biohemorheological profile determined at hospital discharge. Sixty-four patients (59 men), mean age of 58 +/- 12.0 years, transmural myocardial infarction survivors, were prospectively studied for 60 months (32.0 +/- 17 months, median 33 months). The following cardiovascular events (CVE) were analyzed: death, non-fatal infarction, unstable angina, and stroke. Twenty-nine patients had a CVE (nine died). The following parameters were determined at hospital discharge: plasma viscosity, whole blood viscosity, erythrocyte membrane fluidity, erythrocyte aggregation, protein C, plasminogen inhibitor type I (PAI-1), leukocyte count and elastase. The quartiles were determined for each parameter, grouping patients according to these values.

STATISTICS

Group-t-test, Kaplan-Meier survival curve (with log rank test), and Cox logistic regression.

RESULTS

1) Leukocyte count (p < 0.01), protein C activity (p < 0.05) and erythrocyte membrane fluidity (p < 0.05) were predictors of the CVE curve; 2) The higher the value of the leukocyte count quartile, the higher the risk for a CVE (p < 0.05). Patients with a leukocyte count above the median had 4 times more risk for a CVE; 3) The lower the protein C activity, the higher the risk for a CVE. Those with protein C activity lower than the lowest quartile had double the risk; 4) The higher the membrane polarization value (membrane rigidity), the higher the risk of a CVE; 5) By multivariate analysis the 3 parameters were independent predictors of a CVE.

CONCLUSION

In the present group of transmural myocardial infarction survivors a close relationship was established between hemorheologic, hemostatic and inflammatory factors and the cardiovascular events curve during long-term follow-up.

The effect of ethanol on acrylic bone cement

Prosthesis loosening is a major problem associated with the use of poly(methyl methacrylate) (PMMA) bone cement that may be related to a peri-implant vacuolisation commonly observed at bone-cement interface. Methyl methacrylate (MMA) monomer may be one of the cement components partly responsible for the mentioned vacuolisation due to a cytotoxic effect associated to this compound. Alcoholism has been related to bone necrosis in predisposed individuals. Furthermore, ethanol has been shown to clean material with adherent cement debris during cleaning procedure in laboratory. Consequently, we have decided to study whether ethanol will also be related to an increased liberation of MMA from the polymer matrix. 'In vitro' release studies using PMMA plates were conducted to access the role of ethanol on the liberation of the monomer. Contact angle measurements and surface tension estimation were also carried out in order to find a possible effect of ethanol on surface cement properties. Results suggest that ethanol, even in small quantities, enhances the leaching of the monomer from the polymer matrix, but does not considerably change the wettability properties of the cement surface.

A functional promoter polymorphism in the macrophage migration inhibitory factor (MIF) gene associated with disease severity in rheumatoid arthritis

The macrophage migration inhibitory factor (MIF) is a potent pro-inflammatory cytokine and regulates the anti-inflammator effects of glucocorticoids. An important role for MIF within the cytokine cascade is to act in concert with endogenous glucocorticoids to control the set-point and magnitude of the inflammatory response. Elevated expression of MIF in the circulation and in the synovial joint has been documented in rheumatoid arthritis. MIF also has been linked to the development of joint damage and disease pathology in experimental animal models. We describe herein a novel CATT-tetranucleotide repeat polymorphism at position -794 of the human Mif gene and show that it functionally affects the activity of the MIF promoter in gene reporter assays. We describe four genotypes which comprise 5, 6, 7, or 8-CATT repeat units and show that the 5-CATT allele has the lowest level of basal and stimulated MIF promoter activity in vitro. The presence of the low expressing, 5-CATT repeat allele correlated with low disease severity in a cohort of rheumatoid arthritis patients.

RAGE and arthritis: the G82S polymorphism amplifies the inflammatory response

The receptor for advanced glycation end products (RAGE) and its proinflammatory S100/calgranulin ligands are enriched in joints of subjects with rheumatoid arthritis (RA) and amplify the immune/inflammatory response. In a model of inflammatory arthritis, blockade of RAGE in mice immunized and challenged with bovine type II collagen suppressed clinical and histologic evidence of arthritis, in parallel with diminished levels of TNF-alpha, IL-6, and matrix metalloproteinases (MMP) 3, 9 and 13 in affected tissues. Allelic variation within key domains of RAGE may influence these proinflammatory mechanisms, thereby predisposing individuals to heightened inflammatory responses. A polymorphism of the RAGE gene within the ligand-binding domain of the receptor has been identified, consisting of a glycine to serine change at position 82. Cells bearing the RAGE 82S allele displayed enhanced binding and cytokine/MMP generation following ligation by a prototypic S100/calgranulin compared with cells expressing the RAGE 82G allele. In human subjects, a case-control study demonstrated an increased prevalence of the 82S allele in patients with RA compared with control subjects. These data suggest that RAGE 82S upregulates the inflammatory response upon engagement of S100/calgranulins, and, thereby, may contribute to enhanced proinflammatory mechanisms in immune/inflammatory diseases.

[Biohemorheologic factors and cardiovascular events curve in survivors of transmural acute myocardial infarct--24-month follow-up]

INTRODUCTION

Previous reports have shown several biohemorheological disturbances in acute myocardial infarction (AMI), either in the acute phase and after hospital discharge. There is no clearly established relationship between these parameters and the patients' clinical outcome.

OBJECTIVE

To evaluate in transmural AMI survivors, a relationship between biohemorheological parameters and the cardiovascular events curve during a 24 month follow-up period.

METHODS

Sixty-four consecutive patients (58.0 +/- 12.0, 59 men), transmural AMI survivors (30 anterior and 34 inferior) were included in the study. Clinical follow-up was 24 months (at 6, 12 and 24 months). The following cardiovascular events (CVE) were collected: cardiovascular death, stroke, AMI, unstable angina, embolism. We determined, at hospital discharge, these biohemorheological parameters: plasma viscosity, fibrinogen, PAI-1 inhibitor, leukocyte count, C protein (C Pt), erythrocyte aggregation (EA). For each parameter we determined the 25, 50 and 75 percentiles and other significant cut-off point, grouping patients according to these values.

STATISTICS

Group t test, Kaplan-Meier survival curve (with the log rank test), and Cox logistic regression.

RESULTS

(1) Patients with CVE (n = 19) during the 24 months of clinical follow-up had at hospital discharge higher leukocyte count (p < 0.001), lower C Pt (p < 0.01) and lower EA (p < 0.05). (2) The higher the percentile of the leukocyte count higher the probability for a CVE. Patients with leukocyte count above the 50 percentile had 6 times more CVE (p < 0.01); (3) The higher the C Pt lower the risk for a CVE. Patients with C PT lower than the 50 percentile had 9 times more risk for a CVE (p < 0.01), and those above the 75 percentile had no CVE (p < 0.01). (4) For the EA we identified a cutoff point (= 14.5), independent of the percentiles values. Patients with EA below 14.5 had six times more CVE. By multivariate analyses, we identified leukocyte count and C Pt as independent risk predictive factors (p < 0.05).

CONCLUSION

In this group of transmural MI survivors a relationship was established between some biohemorheological (leukocyte count, C Pt, EA) and the CVE curve during 24 months of clinical follow-up.

Numerical-experimental method for the validation of a controlled stiffness femoral prosthesis

The aim of this paper is to describe a new numerical-experimental method to determine the stiffness of a conceptual proximal femoral prototype. The methodology consists of the comparison of the numerical and experimental displacement distributions of the prosthesis loaded as a cantilever beam to validate a design concept: controlled stiffness prosthesis. The manufactured prototype used to test the applicability of the numerical-experimental procedure integrates a stiff metal core bonded to a composite material made of an epoxy resin reinforced with carbon-glass braided pre-forms. The prosthesis with an embedded controlled stiffness concept was obtained by varying the geometry of the core with the composite layer thickness.

The influence of vacuum mixing on methylmethacrylate liberation from acrylic cement powder

Polymethylmethacrylate (PMMA) bone cement is a biomaterial used to anchor prostheses during joint replacement surgery. Residual methylmethacrylate monomer (MMA) may be related with the cytotoxic effect of PMMA. The aim of the present paper was to investigate the effect of two different cement mixing methods: hand stirring at atmospheric pressure and under partial vacuum (0.330 and 0.154 bar) on residual monomer liberation in phosphate buffer saline solution from acrylic cement powder. Residual MMA content was determined by high-performance liquid chromatography. Mathematical models were applied to experimental dissolution data revealing that monomer release was significantly reduced in bone cement powder obtained at 0.154 bar vacuum pressure compared to the other mixing conditions. The kinetic models applied are consistent with a simple diffusion mechanism of the monomer from the polymer matrix.

Recessive ataxia with ocular apraxia: review of 22 Portuguese patients

BACKGROUND

The recessive ataxias are a heterogeneous group of neurodegenerative disorders characterized by cerebellar ataxia associated with a number of different neurologic, ophthalmologic, or general signs. They are often difficult to classify in clinical terms, except for Friedreich ataxia, ataxia-telangiectasia, and a relatively small group of rare conditions for which the molecular basis has already been defined.

OBJECTIVES

To study the clinical presentation and to define diagnostic criteria in a group of Portuguese patients with ataxia and ocular apraxia, an autosomal recessive form without the essential clinical and laboratory features of ataxia-telangiectasia.

PATIENTS AND METHODS

We reviewed 22 patients in 11 kindreds, identified through a systematic survey of hereditary ataxias being conducted in Portugal.

RESULTS

Age at onset ranged from 1 to 15 years, with a mean of 4.7 years. The duration of symptoms at the time of last examination varied from 5 to 58 years. All patients presented with progressive cerebellar ataxia, the characteristic ocular apraxia, and a peripheral neuropathy. Associated neurologic signs included dystonia, scoliosis, and pes cavus. Magnetic resonance imaging was performed in 16 patients, all of whom showed cerebellar atrophy.

CONCLUSIONS

Ataxia with ocular apraxia may be more frequent than postulated before, and may be identified clinically using the following criteria: (1) autosomal recessive transmission; (2) early onset (for most patients in early childhood); (3) combination of cerebellar ataxia, ocular apraxia, and early areflexia, with later appearance of the full picture of peripheral neuropathy; (4) absence of mental retardation, telangiectasia, and immunodeficiency; and (5) the possibility of a long survival, although with severe motor handicap.

In vitro release studies of methylmethacrylate liberation from acrylic cement powder

Bone cement or polymethylmethacrylate (PMMA) is commonly used for anchoring cemented prosthesis to the bone. Cytotoxic effect of culture media exposed to PMMA powder may be related with long term problems associated with acrylic cement application, being the monomer (methylmethacrylate) one of the cement's component partly responsible for the cytotoxic effect. The present work reports the studies of monomer release from acrylic bone cement powder under different experimental conditions: setting time of PMMA (in solution and air) and different culture media composition. High-performance liquid chromatography was used for the determination of residual monomer. Mathematical models were applied to experimental dissolution data revealing that monomer release is lightly affected by the studied variables. The monomer release seems to be a surface phenomena, suggesting that the possible actions of monomer will mainly be due to the initial loss of non polymerized monomer rather than to further depolymerization of the already polymerized cement.

Prenatal diagnosis of abdominal enteric duplications

Alimentary tract duplications are rare congenital malformations with few reports of the antenatal sonographic appearance. Early diagnosis is of paramount importance to prevent complications. We present a case of a cystic gastric duplication diagnosed antenatally at 31 weeks' gestation, which was treated successfully. Simultaneously, we review all published cases of prenatally diagnosed enteric duplications.

Impairment of the erythrocyte membrane fluidity in survivors of acute myocardial infarction. A prospective study

Erythrocytes have to constantly adapt themselves to the varying circulatory system shear stress forces and capillaries diameter. Membrane lipid and protein content have an important role in determining the erythrocyte shape and are main determinants of the membrane solid and fluid behaviour which enables the erythrocyte to respond to the outer environment modifications. Membrane fluidity is an inverse index of membrane microviscosity. The aim of the present work is to evaluate prospectively in three periods of time (discharge, after 6 months and one year later) in survivors of an acute myocardial infarction (AMI) the erythrocyte membrane fluidity (outer and inner bilayer) and establish a relation with the cardiovascular events or need of coronary revascularization during a two year clinical follow up. Sixty survivors of acute myocardial infarction were recruited during 1994-96 and were prospectively studied in three periods (discharge, 6 months and after one year), and were compared with a control group (n = 36). Membrane lipid fluidity was determined by means of fluorescence polarisation with two probes: 1,6-diphenyl-1,2,5-hexatriene (DPH) and 1,4-trimethylamine 6-phenyl hexa-1,3,5-triene (TMA-DPH), for the characterisation of the hydrophobic and external polar region, respectively. The hydrophobic region was more rigidified (p < 0.01) in the erythrocytes from AMI patients, in relation to the control group. During the time of the study there was a progressive erythrocyte membrane rigidification (DPH p < 0.001; TMA-DPH p < 0.001). We found no relation between erythrocyte membrane fluidity and the coronary risk factors, cardiovascular events or the need of coronary revascularization during the clinical follow-up. In conclusion, after the myocardial infarction erythrocyte membrane of AMI survivors becomes more rigid with time, which could contribute to the decreased erythrocyte deformability and the increased blood viscosity previously described in this group of patients.

Clonal expansion within CD4+ and CD8+ T cell subsets in human T lymphotropic virus type I-infected individuals

To investigate the diversity of the T cell repertoire involved in human T lymphotropic virus type I (HTLV-I) infections, peripheral blood T cell subsets were analyzed by using a PCR-based assay that permits determination of complementarity-determining region 3 (CDR3) length variation in TCR Vbeta transcripts. In two of four asymptomatic HTLV-I carriers and in four of five patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), mono- or oligoclonal expansions were detected in the CD4+ T cell subset. In one patient with adult T cell leukemia, a specific clone bearing Vbeta7 was detected in the CD4+ T cell subset. In contrast, clonal expansion was not observed in the CD4 T cell subsets of three individuals with asymptomatic HTLV-II infection or in our previous studies of a large number of uninfected individuals. Oligoclonal expansions in the CD8+ T cell subset were detected in all subjects, including the patient with adult T cell leukemia. No differences in the number of expanded clones were noted between asymptomatic carriers and in patients with HAM/TSP and there was no obvious restriction in the TCR V region usage. Direct sequencing revealed no significant bias in the CDR3 motifs utilized by the predominant clones. This report is the first direct demonstration of clonal expansions within fractionated T cell subsets (CD4+ and CD8+) in HTLV-I infections and suggests that 1) clonal expansion of CD4+ T lymphocytes likely occurs as a direct result of infection and 2) polyclonal CD8+ T cell expansion occurs frequently and independently of disease association.

Commitment to X inactivation precedes the twinning event in monochorionic MZ twins

To gain insight into the timing of twinning, we have examined a closely related event, X-chromosome inactivation, in female MZ twin pairs. X-inactivation patterns in peripheral blood and buccal mucosa were compared between monochorionic MZ (MC-MZ) and dichorionic MZ (DC-MZ) twins. Overall, the MC-MZ twins displayed highly similar X-inactivation patterns, whereas DC-MZ twins frequently differed in their X-inactivation patterns, when both tissues were tested. Previous experimental data suggest that commitment to X inactivation occurs when there are 10-20 cells in the embryo. Simulation of embryo splitting after commitment to X inactivation suggests that MC-MZ twinning occurs three or four rounds of replication after X inactivation, whereas a DC-MZ twinning event occurs earlier, before or around the time of X inactivation. Finally, the overall degree of skewing in the MZ twins was not significantly different from that observed in singletons. This indicates that X inactivation does not play a direct role in the twinning process, and it further suggests that extreme unequal splitting is not a common mechanism of twin formation.

[Inflammatory smears in cervicovaginal cytology. A finding meaning infection?]

INTRODUCTION

Inflammatory changes are relatively frequent findings in cervical smears and are generally believed to be a consequence of genital infection. However, clinical signs of infection are frequently absent and no consensus exists on the management of these patients. The objective of this study was to assess whether or not inflammatory smears are exclusively a consequence of genital infection. For this purpose, the prevalence of genital infection in a group of women with inflammatory cells in the cervical smear and a control group with normal smears was compared.

MATERIAL AND METHODS

Sixty-two regularly menstruating women aged 17 to 48 years, attending the outpatient Gynaecology sector of S. João Hospital, were prospectively evaluated. Cervical smears were analysed by the same cytologist who chose 10 inflammatory cells per high power field (400x) as the cut-off value for normality. Infection by Candida spp., Trichomonas vaginalis, Neisseria gonorrhoeae, Mycoplasma hominis, Ureaplasma urealyticum, Chlamydia trachomatis and bacterial vaginosis was investigated. Human Papillomavirus infection was evaluated by colposcopy and biopsy of abnormal colposcopic findings.

RESULTS

Thirty-four women and inflammatory cells on their cervical smear and 15 of these (44%) had a genital infection. Of the 28 women with normal smears, 12 (43%) had a genital infection. No statistically significant difference in the prevalence of infection was found between the two groups.

CONCLUSIONS

Our results suggest that the presence of inflammatory cells in cervical smears is not necessarily due to infection and other causes may be responsible for their appearance.

Acrylic bone cement induces the production of free radicals by cultured human fibroblasts

Arthroplasty with poly(methyl methacrylate) (PMMA) bone cement induces late loosening phenomena that compromise the prosthetic stability. As free radicals are inflammatory mediators and cytotoxic, it seemed useful to investigate whether PMMA induces the liberation of free radicals and/or cytotoxicity. The effect of PMMA interaction on cultured human fibroblasts was accessed by the cell viability test (MTT), and by the measurement of lipoperoxides in the incubation medium. The incubation with the medium exposed to PMMA induced a significant reduction in the viability and a significant increase in lipoperoxide liberation (vs control). These data suggest that PMMA is cytotoxic. This effect seems to be mediated by lipoperoxide and possibly by other free radicals, and may explain the peri-implant loosening phenomena that compromise the prosthetic stability.

[Angina pectoris with normal coronary arteries]

The occurrence of angina pectoris in patients with normal coronary angiograms is a subject of investigation since its first description as an entity in 1967. Its etiology remains unknown but, in the absence of disease of the epicardial coronary arteries, dysfunction of the small, most distal vessels and the endothelium appear to be incriminated. In this review, the most recent knowledge and understanding of the pathophysiology, clinical presentation and management of this syndrome is presented.

[The stress electrocardiogram in the evaluation of angina pectoris]

The exercise tolerance test (ETT) is the ancillary test of choice for the evaluation of the patient with ischaemic heart disease. When faced with complaints suggestive of angina pectoris, ETT is useful in confirming or excluding such a diagnosis, frequently reproducing the complaints while recording the tell-tale electrocardiographic signs of ischaemia--ST segment deviation. Additionally, the ETT provides information on the severity of the disease and is also valuable for the risk stratification of future coronary events. This information as a whole can be used both in the diagnosis and in the management of the patient with coronary artery disease.

Clonal expansion within the CD4+CD57+ and CD8+CD57+ T cell subsets in chronic lymphocytic leukemia

The role of T cells in chronic lymphocytic leukemia (CLL) has not been extensively investigated, since the most prominent cellular abnormality in CLL involves the clonal expansion of B cells. In this study we have undertaken a comprehensive analysis of the CD4+ and CD8+ T cell repertoire in a population of CLL patients (n = 19) and age-matched controls (n = 22). The TCR repertoire analysis was performed using a multiplex PCR assay for CDR3 length, an approach that allows for the detection of underlying oligoclonality in complex T cell populations. We established that oligoclonality was substantially more frequent in both the CD4+ and CD8+ T cell populations of CLL patients than in the age-matched controls (p &lt; 0.001). Using three-color FACS analysis with a panel of TCRV segment-specific mAbs, we also established that oligoclonal expansions are predominantly found in the CD57+ subset of both the CD4+ and CD8+ T cell populations. The frequency of the CD57 marker on CD4+ T cells was increased in the setting of CLL (% CD57 = 14.8 +/- 13.0%) compared with that in normal controls (% CD57 = 3.3 +/- 3.0%; p &lt; 0.001). An elevated frequency of CD4+CD57+ T cells was correlated with more advanced disease. Similarly, the most extreme oligoclonal expansions of CD4+CD57+ T cells occurred in CLL patients who had progressed beyond Rai stage 0. These data document profound alterations in the T cell repertoire of CLL patients and point to a role for clonal T cell populations in the pathogenesis of this disease.

[Delayed primary anastomosis in esophageal atresia without fistula. 10 years' experience]

From 1984 until 1994 there were 7 cases of newborn with esophageal atresia without fistulae, five of which were treated through primary anastomosis and two of these presented exceptional long gaps. This article is an analysis of these 7 newborns, their post-operative complications and the therapeutics used. Two deaths occurred due to associated serious cardiac pathologies, which made delayed primary anastomosis impossible, and one sudden death four months after the esophageal anastomosis. Three of these cases present a good stature-weight progression and one remains slightly under the 5 percentile. Considering our results, the delayed primary anastomosis in the esophageal atresias with long gap, in spite of the post-operative complications, shall continue to be the author's choice.