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Biomedical subjects

M Zabel

Publications and source records attributed to M Zabel.

212 records · Page 12Linked to original sources
PubMedDate not supplied

Electrophysiological basis of QT dispersion measurements.

Dispersion of ventricular repolarization is a now widely used term describing nonhomogeneous recovery of excitability or heterogeneity of ventricular repolarization. It is usually expressed as the difference or the range of various repolarization measurements obtained from a heart. Experimentally, an increased dispersion of ventricular repolarization was found to be tightly associated with increased propensity for ventricular arrhythmias, and, therefore, is considered an important arrhythmogenic mechanism. Noninvasively, this arrhythmogenic substrate was approached using multilead body surface potential mapping, but also QT interval dispersion (QTd) and similar electrocardiogram (ECG) variables from the 12-lead surface ECG. Standard QTd from the ECG correlates significantly with dispersion of repolarization measured from the myocardium. A causal relationship is, however, still unclear, and there are 2 main hypotheses to explain the electrophysiological basis of QTd. The local hypothesis explaining QTd with spatial differences in action potential duration mirrored in the various QT intervals competes with the global hypothesis explaining the variation in surface ECG measurements with different projections of a common T-wave vector. Notwithstanding the final explanation for QTd, and particularly for technical reasons, new markers like advanced T-wave loop variables may best reflect the abnormal repolarization substrate on the surface ECG.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Unfavorable prognostic value of CD24 expression in sections from primary and relapsed ovarian cancer tissue.

Expression of CD24 represents a poorly recognized, unfavorable prognostic factor. Expression of the protein is supposed to facilitate extravasation of tumor cells. Our study aimed at examination of prognostic significance of CD24 estimation in samples obtained from primary surgeries (PS) and secondary cytoreductions (SCR) (after chemotherapy) in ovarian cancer patients. The analyses were performed on sections originating from 73 tumor samples. Immunohistochemical reactions were performed on paraffin sections of studied tumors, using monoclonal antibodies against CD24. Kaplan-Meier's analysis showed that a significantly shorter overall survival time and progression-free time was demonstrated to characterize cases with cytoplasmic membranous expression of CD24 (CD24c-m) (P < 0.001). The calculations performed demonstrated also a significantly higher proportion of CD24c-m positive cases in sections from SCR as compared to that from PS (P= 0.04) and in cases of progressive disease as compared to complete response at PS and SCR (P= 0.002 and P= 0.05, respectively). Summing up, in this study, we have demonstrated a negative prognostic significance of a cytoplasmic membranous expression of CD24 in cases of ovarian cancer.

Antibodies, Monoclonal↗
PubMedDate not supplied

Expression of aminopeptidase N/CD13 in human ovarian cancers.

Aminopeptidase N/CD13 (EC 3.4.11.2) is suggested to play a role in cancer cells invasion, and its activity can be inhibited using specific inhibitors. CD13 inhibitors evoke apoptosis of CD13-positive cancer cells. However, expression of CD13 has not been described in specimens obtained from ovarian carcinomas. Thus, in the present study, the expression of CD13 and its significance was examined in samples of ovarian cancers. The analyses were performed on sections originating from 73 tumor samples (43 from primary laparotomies [PL] and 30 from secondary cytoreductions [SCRs]). Immunohistochemical reactions were performed on paraffin sections of studied tumors, using monoclonal antibodies against CD13. The analysis demonstrated no relationships between the expression of CD13 on one hand and clinical variables and pathologic variables of the patients on the other hand. Expression of CD13 was demonstrated to be significantly more pronounced in samples obtained in PLs as compared to samples from SCRs (P < 0.001). Thus, the data indicate that a potential treatment of ovarian carcinoma with CD13 inhibitors should be performed before chemotherapy or in parallel to first-lapse chemotherapy.

Aged↗
PubMedDate not supplied

Analysis of the expression of estrogen and progesteron receptors, and of PCNA and Ki67 proliferation antigens, in uterine myomata cells in relation to the phase of the menstrual cycle.

BACKGROUND: The purpose of this study was to provide an immunocytochemical evaluation of the expression of receptors for estrogens (ER) and progesterone (PgR), and of Ki67 and PCNA (proliferating cell nuclear antigen) proliferation antigens in uterine myomata cells in three groups of patients operated in various phases of the menstrual cycle, and to determine the relationship between the expression of the receptors, the proliferative activity of myoma cells, and the phase of the menstrual cycle during which the tumor was excised. MATERIAL AND METHODS: The studies were performed on samples of uterine 85 leiomyomata. Twelve of the patients were operated in the follicular phase of menstrual cycle, 50 in the luteal phase, and 27 in the post-menopausal period. The receptors and proliferating antigens were detected immunocytochemically. The intensity of the immunocytochemical reaction was evaluated using the ImmunoReactive Score (IRS). RESULTS: In all three groups of patients the expression of PgR significantly exceeded that of ER. Also, in all the patients the mean expression of PCNA significantly exceeded the expression of Ki76. CONCLUSIONS: The expression of the studied antigens did not depend upon the phase of the menstrual cycle, and was similar in the postmenopausal period.

Adult↗
PubMedDate not supplied

[Pathologic anatomy of white atrophy].

Milian's respectively aetiological and pathogenic hypotheses, based on the infectious origin of this disease, such as tuberculosis or syphilis, have not been confirmed. In almost every case there has proved to be chronic venous deficiency. The histomorphological deterioration shows, as well as the characteristic signs of cutaneous atrophy, the vessel affection developing towards dilation, but also the parietal processes moving towards obliteration. These processes do not correspond to vasculitis, as described by Ruiter. For this reason, we do not go along with those authors associating these histological deteriorations with vasculitis. And we therefore justify our claim that white atrophy cannot be considered as an angiolopathy.

Atrophy↗
PubMedDate not supplied

[Ultraviolet sensitivity in skin of the aged].

The sensitivity for ultraviolet rays of the skin on the back was determined in 340 men and women being more than 49 years of age. We used the "light staircase" applied by Wucherpfennig and Mathiesen. We found a great variation in the results. Neither age nor season showed a significant influence on the ultraviolet erythema threshold in older persons. Only sex seemed to have an influence.

Adult↗
PubMedDate not supplied

[Is the pigmentation a characteristic sign for chronic venous insufficiency?].

In epidemiological studies pigmentations were declared a decisive criterium of stadium II of chronic venous insufficiency. It is discussed in this work if it is possible as the pigmentation is sometimes absent in advanced stages of chronic venous insufficiency. On the other hand it has got to be considered that there are many other possibilities of pigment building on the legs without chronic venous insufficiency. Pigmentation may be of actinic, endocrine, atrophic or especially of inflammatory origin. These pigmentations cannot be differentiated from those caused by chronic venous insufficiency macroscopically, and therefore, in our opinion, the question if pigmentation is a specific sign for chronic venous insufficiency has to be negated. Further, it is examined if the histomorphology of the pigmentation caused by chronic venous insufficiency offers a different aspect from that caused by other diseases. Special attention is given to the pigments containing melanin and iron. Melanin, as an example, is increased in skin inflammation whether there is chronic venous insufficiency or independent of any edematous changes, In subfascial chronic venous insufficiency without any inflammatory component, only the pigment containing iron increased.

Chronic Disease↗