Corália Vicente

Haemochromatosis as a window into the study of the immunological system : a novel correlation between CD8+ lymphocytes and iron overload

Abstract: In the present study we report a serial investigation of the numbers of the peripheral blood cells — erythrocytes, polymorphonuclear neutrophils, total lymphocytes, T‐lymphocyte subpopulations (CD2, CD4, CD8), B lymphocytes and monocytes — in a group of 21 patients with haemochromatosis during the time of intensive phlebotomy treatment, i.e., from iron overload until the onset of iron deficiency. A remarkable individual stability of all blood cell populations studied was found in all patients. Patients differed in their relative proportions of CD4+ and CD8+. Each individuals CD4/CD8 ratio, as well as the absolute numbers, remained unaffected with time, confirming the existence of a strict homeostatic regulation of the relative numbers of the two major peripheral T lymphocytes. A significant positive correlation between CD4/CD8 ratios and the amount of iron mobilised by phlebotomy was found during this study. A novel correlation between the relative proportions of CD4+ and CD8+ cells and iron overload is confirmed by the follow‐up of iron re‐entry in the serum transferrin pool in the treated patients.

Immunohistochemical expression of vascular endothelial growth factor in canine mammary tumours.

The histopathological and clinical aspects of canine mammary tumours (CMTs) have been widely studied, but the variation in the biological behaviour of these neoplasms hampers the identification of prognostic factors. Sustained angiogenesis has been suggested to be one of the most important factors underlying tumour growth and invasion. This process involves the action of several growth factors including vascular endothelial growth factor (VEGF). The present study characterizes the relationship between immunohistochemical expression of VEGF and gross (e.g. size and tissue fixation) and microscopical (e.g. type, growth, necrosis, lymphoid infiltration, lymph node metastasis, histological grade and proliferation index) features of CMTs. Forty-eight benign and 64 malignant CMTs were evaluated. Statistical analysis failed to show a significant relationship between VEGF expression and the pathological features, suggesting that VEGF expression occurs in both benign and malignant tumours and is independent of histological type, proliferation, tissue invasion or local metastatic capacity.

Immunohistochemical analysis of urokinase plasminogen activator and its prognostic value in canine mammary tumours

Urokinase plasminogen activator (uPA) has been associated with aggressive behaviour and poor prognosis in human breast cancer, but there is no information on its expression in canine mammary tumours (CMT). uPA immunohistochemical expression was studied in 119 CMT (24 benign, 95 malignant) to investigate its relationship with clinical and histopathological parameters. Dogs with malignant mammary tumours (MMT) underwent a 2-year follow-up evaluation. MMT expressed significantly more uPA than benign tumours. In MMT, high uPA stromal expression was significantly associated with larger tumour size, high Ki-67 expression, invasive growth, high histological grade, regional lymph node metastases, development of distant metastases, and lower overall survival (OS) and disease-free survival (DFS). On the basis of these results, uPA could be considered a useful prognostic factor in dogs with MMT.

Immunohistochemical evaluation of MMP-2 and TIMP-2 in canine mammary tumours: a survival study.

Canine mammary tumours (CMTs) are a very heterogeneous group of neoplasms with variable prognosis. Their aggressiveness is mainly due to their ability to invade locally and to metastasize. The degradation of extracellular matrix components is an important determinant of the invasive phenotype. The aims of this study were to analyse by immunohistochemistry and double immunofluorescence the expression of metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in eight normal canine mammary glands and 118 CMTs (24 benign, 94 malignant) and to investigate relationships with metastatic disease and survival. MMP-2 and TIMP-2 expression was higher in malignant tumours than in normal canine mammary tissue and benign tumours. The main difference between benign and malignant CMTs was the pattern of expression of both molecules: benign tumours presented TIMP-2 and MMP-2 immunoreactivity in the myoepithelial cells lining the basement membrane of tubuloalveolar structures, while malignant tumours showed mainly diffuse expression in neoplastic cells. In malignant tumours, increased TIMP-2 expression was significantly associated with the development of distant metastases, lower overall survival and lower disease-free survival. MMP-2 expression was not significantly associated to any of these parameters. These results suggest that the immunohistochemical expression of TIMP-2 is a useful prognostic factor in CMTs.

Growth and osmoregulation in Salmo salar L. juveniles 1+, 1½ + and 2+ reared under restrained salinity

The freshwater phase of Atlantic salmon Salmo salar L vary between one and eight years. The reduction of the freshwater phase is desirable to reduce freshwater usage, human resources and to increase year round availability of pan-sized salmon. Three trials were conducted to investigate the possibility of supply the market in a year-round basis, with pan-sized Atlantic salmon Salmo salar L. (250-300 g) in Portugal (southern limit of the natural distribution of this species). This study primarily aimed to compare the osmoregulatory ability and growth of different fish sizes, smolts 1+ (trial 1), 1.5+ (trial 2) and 2+ (trial 3), in freshwater and seawater conditions. Additionally, effects of photoperiod were determined in smolts 1.5+ (trial 2) for both freshwater and seawater groups. The increments in the plasma osmolality and chlorine concentrations after seawater transfer suggest an identical development in the hypo-osmoregulation capacity among the different age classes. In all trials, weight gain was smaller after 30 d of saltwater transfer when compared to fish reared in freshwater. However, the growth depression was temporary. Seawater group showed a compensatory growth in the immediate months, which permitted an improvement in growth rates. At the end of trials there were minor differences on growth performance between freshwater and seawater groups. Specific growth rates varied between 0.7 and 1.0 % day-1, according to the age and /or size and transfer season.

Cardiac venous arterialization in acute myocardial infarction: how great is the benefit?

OBJECTIVES Cardiac venous arterialization has been proposed as an alternative approach for myocardial revascularization in ischaemic heart disease. It is based on using the cardiac venous system to transport arterial blood from a systemic artery to infarcted myocardial areas. Our goal was to evaluate its benefit in reducing acute myocardial infarct size and its effects on cardiac performance. METHODS In a group of pigs, the left internal mammary artery was anastomosed to the left anterior descending vein; this vein was ligated proximally. The left anterior descending coronary artery was also occluded. Over 5 days, several diagnostic procedures were used to characterize and measure the extent of myocardial infarct, namely ECG, echocardiography, cardiac biomarkers and histopathology. Data were compared with those from a control group of pigs, which were submitted to ligation of only the left anterior descending coronary artery. RESULTS In the experimental group, echocardiography revealed that the ejection fraction and thickness of the ventricular walls remained unchanged 4 days after surgery, in contrast to the major alterations in the control group. In fact, the ejection fraction in the control group decreased by 21% (P < 0.001), with a reduction of 31% (P < 0.004) in the thickness of the interventricular septum at end systole and enlargement of the left ventricular lumen by 28% (P < 0.001). In the experimental group, the sum for ST segment shift was 50% lower (P = 0.038) and the total ventricular histological lesion size was 50% smaller (P < 0.001). Within this lesion, the area of necrotic tissue was 70% smaller (P < 0.001). Cardiac biomarkers were not different between the two groups (P > 0.2). CONCLUSIONS This study reveals that selective cardiac venous arterialization can nourish the myocardium and is able to reduce infarct size by more than 50%, while protecting cardiac performance. We believe, therefore, that further investigation should be carried out into this technique in order for it to be considered as an option in coronary surgery.

Folk Health Wisdoms as an Alternative Health Care Modality in the Community

This study aimed to investigate perceptions and practices of folk health wisdoms among various age groups in Thailand. The study used an exploratory design involving a survey and focus group discussions. Between March 2003 and April 2005, 422 respondents from 5 communities of different districts of Chonburi Province, Thailand were interviewed, and then followed up for clarification of responses by focus groups in each community. Most respondents (93.8%), especially in the older age groups, were familiar with and interested in folk health wisdoms, with 62.8% using one or more kinds of folk health wisdoms. Herbal medicines and massage were most often used as health care, with significant differences in use (p < .05) between younger and older age groups. Younger people (<35 years) used almost every type of folk health wisdom in lesser percentages, with the exception of mind control therapies. Greater use of folk health wisdoms could contribute to improving the health care of the people of Thailand. However, to appropriately use and integrate these practices, the people need to increase their confidence in these modalities and be encouraged by the official health system.