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Biomedical subjects

T Mattfeldt

Publications and source records attributed to T Mattfeldt.

At least 55 records · Page 3Linked to original sources
PubMed1996

Serous cystadenocarcinoma of the pancreas.

The mucinous type of cystadenoma of the pancreas is known to have malignant potential, whereas the serous type is believed to be benign. Therefore, the therapeutic strategies for serous cystadenomas are less aggressive than in mucinous cystadenoma, where complete operative resection is the procedure of choice. A patient with a biopsy-proven serous cystadenocarcinoma with a lymph node metastasis is reported. Considering the reported case and a review of the literature, the origin of serous cystadenocarcinoma appears to be from cystadenoma lesions. Even if this development of cystadenocarcinoma in pre-existing serous cystadenoma lesions is a rare entity, a less aggressive treatment of this lesion should be avoided in favor of resection procedures because of the good chance of cure.

Aged↗
PubMed1996

[Solid pseudopapillary tumors of the pancreas].

We report on three female patients with solid pseudopapillary tumors of the pancreas. The histogenetic origin of this entity is still unclear. The tumor, usually occurring in young women, forms large masses (up to 10 cm in diameter) before becoming symptomatic. Metastases have very rarely been reported. In contrast to other pancreatic tumors, the main pancreatic duct was displaced, but of normal caliber without stenosis, in all our patients. Despite the large size of the tumors, they were curatively resected in all three cases. Two of the tumors infiltrated the parenchyma or adipose tissue of the pancreas but did not spread into the lymph nodes or other organs. All of the patients are alive and without signs of tumor recurrence up to 8 years after surgical resection.

Adult↗
PubMed1996

Reversible metastatic pulmonary calcification in a patient with multiple myeloma.

A-52-year-old patient presented with a 2-year history of multiple myeloma, recurrent episodes of hypercalcemia, and extensive bone involvement. She developed pulmonary infiltrates, initially misdiagnosed as interstitial pneumonia. High-resolution computed tomography and bone scintiscanning indicated pulmonary calcification, which was confirmed by a transbronchial biopsy. Cytostatic treatment of multiple myeloma in combination with repetitive i.v. administration of bisphosphonates over a period of 6 months led to a significant improvement of clinical symptoms. Regression of pulmonary infiltrates was demonstrated by chest radiograph and computed tomography. There are only a few reports on pulmonary calcification in patients with multiple myeloma; the condition was associated mostly with progressive disease, kidney failure, adult respiratory distress syndrome and bad prognosis. In our patient isolated calcification of the lungs without involvement of other organ systems was successfully treated. These findings suggest that interstitial pulmonary calcinosis in multiple myeloma can be reversed by normalization of serum calcium levels using bisphosphonates combined with cytostatic treatment.

Antineoplastic Agents, Alkylating↗
PubMed1996

Increased endothelin release by cultured human smooth muscle cells from atherosclerotic coronary arteries.

OBJECTIVES: Endothelin, a 21-amino acid peptide initially purified from the medium of cultured endothelial cells, is a potent vasoconstrictor exerting its effects predominantly in a paracrine or autocrine manner. Recent data indicate that endothelin is also synthesized by cultured vascular smooth muscle cells and that endothelin is an effective stimulator of smooth muscle cell proliferation. This study aimed to investigate the endothelin release of cultured human smooth muscle cells, isolated from coronary plaques and from normal coronary tunica media, and to determine circulating endothelin concentrations in patients with coronary artery disease compared to control subjects. METHODS: Coronary plaque material was extracted by thrombendarterectomy during aorto-coronary bypass grafting (n = 19). Segments of normal coronary arteries were obtained at autopsy (n = 33). Cells were isolated by enzymatic disaggregation and identified as smooth muscle cells with antibodies against smooth muscle alpha-actin. Venous blood samples were drawn from patients with coronary artery disease undergoing cardiac catheterization (n = 32) and from control subjects (n = 38). Endothelin concentrations in culture medium and in plasma samples were measured by radioimmunoassay after Sep Pak C18 extraction. RESULTS: Cultured smooth muscle cells, isolated from coronary plaques, released a significantly (P < 0.001) higher amount of immunoreactive endothelin into the culture medium (39.2 +/- 3.9 pg/10(4) cells, mean +/- s.e.m., 31 supernatant samples) than smooth muscle cells from normal coronary tunica media (3.9 +/- 0.8 pg/10(4) cells, 28 samples). Circulating endothelin concentrations were slightly elevated (P < 0.01) in patients with coronary artery disease (3.8 +/- 0.2 pg/ml) compared to control subjects (3.0 +/- 0.2 pg/ml). CONCLUSIONS: These data suggest that the endothelin production is markedly increased in smooth muscle cells of coronary atherosclerotic plaques. The enhanced endothelin release may stimulate smooth muscle cell proliferation in a paracrine or autocrine manner and thus may contribute to the development or progression of coronary artery disease.

Cells, Cultured↗
PubMed1996

Centred contact density functions for the statistical analysis of random sets. A stereological study on benign and malignant glandular tissue using image analysis.

Real structures investigated in the material and biological sciences, such as minerals or tissues, can often be reduced to two phases. In a stochastic approach, the components of such binary structures may be considered as the union of grains--random sets implanted with their centres at random points--and their complementary space, which is called the pore space. The simplest stochastic germ-grain model is the Boolean model of random sets, which we use here instrumentally as a null model (reference model) for comparison with our biological material. After a brief review of basic properties of the Boolean model and related statistical methods, we introduce centred contact density functions as a new approach. Empirical contact density functions are estimated from the empirical contact distribution functions with an image analyser by dilation of the grain phase. Theoretical contact density functions are then predicted from a set of image parameters, under the assumption that the Boolean model holds. A centred contact density function is the difference between the estimated and the predicted contact density function. Apart from a random error term, centred contact density functions amount to zero irrespective of the area fraction of the grain phase, when the germ-grain model is Boolean. As a section of a spatial Boolean model is a planar Boolean model, the method is also applicable in stereological studies where digitized images are obtained from sections of a three-dimensional structure. Centred contact density functions were determined for mastopathic tissue as compared to mammary cancer, and for tumour-free prostatic tissue as compared to prostatic cancer. For each category of specimens, twenty cases with 10 images each were analysed. Benign and malignant glandular tissue of the aforementioned types deviates significantly from the Boolean model. Centred contact density functions show that malignant transformation is connected with profound geometric remodelling of the pore space.

Breast Neoplasms↗
PubMed1996

Predictive value of magnetic resonance imaging and computerized tomography for conservative renal surgery in an ex vivo tumor enucleation study followed by step-sectioning.

PURPOSE: Due to the early diagnosis of many renal cell cancers, the treatment options of organ conserving surgery is of interest even for patients with a normal contralateral kidney. To our knowledge the predictive value of preoperative investigations in such patients has not been clarified. MATERIALS AND METHODS: In a prospective study of 30 patients with stage T1/T2 renal cell carcinoma ex vivo enucleation was performed following tumor nephrectomy. Magnetic resonance imaging (MRI) and computerized tomography (CT) were done preoperatively in all patients. For pathological evaluation the kidneys were step-sectioned in 1 mm. slices. Macroscopic and microscopic findings were compared to those of the preoperative investigations. RESULTS: Mean tumor diameter was 4.6 cm. (range 2.0 to 10.0). Twelve tumors were incidental and smaller than 4 cm. Residual carcinoma due to incomplete resection was found in 4 kidneys with tumors larger than 4 cm. Parenchymal or hilar venous invasion was noted in 4 cases, including 1 in the incidental group. Prediction of renal fat capsule invasion by MRI was highly confirmed by pathological examination. On the other hand, parenchymal venous involvement or secondary renal tumors smaller than 2 cm. could not be predicted by MRI or CT. CONCLUSIONS: Neither MRI nor CT predicts complete tumor control when conservative renal surgery is considered. All incidental tumors smaller than 4 cm. could be resected completely by nephron sparing surgery. Nevertheless, microscopic venous invasion was present in 1 of the latter cases.

Adult↗
PubMed1995

Effect of acadesine treatment on postischemic damage to small intestine.

Hemorrhagic mucosal lesions are produced during intestinal ischemia and after reperfusion due at least in part to the accumulation and activation of polymorphonuclear leukocytes in the tissue. It has been shown in vitro that adenosine is instrumental in attenuating this pathophysiological process. Acadesine [5-amino-4-imidazolecarboxamide (AICA) riboside], a purine nucleoside analogue, increases the availability of adenosine in the tissue. The aim of the study was therefore to assess the influence of acadesine treatment on neutrophil accumulation, purine metabolism, and mucosal damage after intestinal ischemia and reperfusion. Intestinal ischemia was induced in cats by partial occlusion of the superior mesenteric artery for 2 h. Samples of the small intestine were exercised before and at the end of the hypotensive period as well as 10 and 60 min after reperfusion. Conjugated dienes, myeloperoxidase, and reduced and oxidized glutathione, as well as the purine metabolites, were determined in the tissue samples. The tissue was also examined histologically. Six cats received saline, and six cats were treated initially before ischemia with acadesine (2.5 mg/kg body wt i.v.) over 5 min as a bolus. Thereafter, acadesine (0.5 mg.kg-1.min- i.v.) was given continuously during ischemia and 30 min after reperfusion. Acadesine treatment significantly attenuated the mucosal lesions seen during reperfusion. This improvement was due at least in part to the inhibition of neutrophil accumulation, as judged by low myeloperoxidase levels. The prevention of neutrophil activation resulted most likely from increased adenosine concentrations in the intestinal tissue in the early reperfusion period.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminoimidazole Carboxamide↗
PubMed1993

Familial occurrence of agonadism and multiple internal malformations in phenotypically normal girls with 46,XY and 46,XX karyotypes, respectively: a new autosomal recessive syndrome.

We report on 2 phenotypic sisters, one with 46,XY; the other with 46,XX. The 2 girls had similar related internal malformations, including agonadism, hypoplasia of the right pulmonary artery, hypoplasia of the right lung, isolated dextrocardia with complex vitium cordis, and diaphragmatic hernia (only sib 1) or omphalocele (only sib 2). This combination of malformations did not fit into any of the previously described syndromes. For this syndrome we suggest the acronym PAGOD ([hypoplasia of the] pulmo, and pulmonary artery, agonadism, omphalocele/diaphragmatic defect, dextrocardia). The occurrence of a basically similar set of malformations in 2 unlike sex is interpreted as evidence for autosomal recessive inheritance. The different gonosomal status excludes the Y chromosome as a responsible factor. The peculiar finding of a 46,XX sex chromosome constitution combined with agonadism and an intact urogenitral tract emphasizes the concept of secondary regression of Wolffian and Müllerian structures. The associated malformations of mesodermal structures can be interpreted as midline defects. We suggest that, from the developmental field perspective, secondary regression of midline structures including the gonadal anlage explains the pathogenesis reasonably well.

Abnormalities, Multiple↗
PubMed1993

Analytic morphology in clinical and experimental dermatology.

During the past several years, quantitative morphology has gained increasing attention in diagnostic pathology and in certain research applications. In the field of dermatopathology, quantitative morphology has been applied to numerous problems, ranging from the interactive measurement of nuclear contours to fully automated, high-resolution image analysis of ultrastructural micrographs. Dermatologic applications are reviewed, and potential developments in the future are briefly outlined.

Animals↗
PubMed1993

Second-order stereology of benign and malignant alterations of the human mammary gland.

The purpose of the present study was a quantitative characterization of the three-dimensional arrangement of the epithelial component of benign and malignant alterations of the female breast by combining stereology with stochastic geometry. Twenty cases of fibrous mastopathy and 20 cases of invasive ductal mammary cancer were studied at the light microscopic level. Segmentation of the epithelial tissue component was performed with an image analyser. From the resulting binary images, unbiased estimates of the covariance C(r) and the intensity Vv of the epithelial volume component were obtained automatically by computer. From these data, estimates of the correlation function k(r), of the pair correlation function g(r), of the radial distribution function RDF(r) and of the reduced second moment function K(r) of epithelial volume were determined. The estimates of C(r) and RDF(r) differed between groups, but these functions depend on spatial pattern and Vv. As carcinomas showed a significantly higher epithelial volume density Vv than mastopathies, estimation of C(r) and RDF(r) alone did not permit a safe distinction between possibly different types of spatial arrangement of epithelium in the benign and malignant lesions. Analysis of the estimates of k(r), g(r) and K(r), which are not influenced by Vv, showed definite interaction between epithelial volume elements, with clustering at short distances and repulsion at long distances. In both groups, the null hypothesis of purely random arrangement of epithelium had to be rejected. The clearest distinction between groups was obtained by estimation of g(r), which showed that short-range, tubular pattern as well as long-range, lobular architecture are better preserved in benign than in malignant lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

[Three-dimensional spatial texture of adenocarcinoma of the prostate by a combination of stereology and digital image analysis].

Second-order stereology combines stereology with stochastic geometry and digital image analysis to obtain an insight into the spatial architecture (texture) of tissues. In twenty radical prostatectomy specimens from patients with invasive adenocarcinomas of the prostate gland, the pair correlation function of the epithelial tissue component was estimated both for the carcinomatous and the tumour-free domains. After interactive segmentation of the gray level images, the method works fully automatically. The mean pair correlation function of carcinomatous tissue shows less clustering of epithelium at short distances and less rhythmicity of epithelium at long distances as compared to tumour-free tissue. This loss of glandular integrity is higher in cribriform than in tubular carcinomas. The results suggest that second-order stereology is a powerful tool for the objective evaluation of glandular differentiation.

Adenocarcinoma↗
PubMed1992

Physiological growth of arteries in the rat heart parallels the growth of capillaries, but not of myocytes.

Maladaption to hemodynamic overload, especially to arterial hypertension, has important clinical implications, and it is necessary to obtain criteria in order to discriminate physiological and pathological growth processes. We investigated the physiological growth of intramyocardial arteries in the rat heart. A new stereological method was introduced to determine the length of intramyocardial arteries from counts on histological sections. Four groups of male Sprague-Dawley rats of different ages were investigated. The growth rate of arteries was characterized by the growth coefficient b according to the exponential function y = axb (allometric growth function). Analysis of left ventricular weights (LVW) and total lengths of left ventricular intramyocardial arteries (L) revealed Lv = constant.LVW0.71 (r = 0.77, P < 0.001). The growth coefficient b < 1 indicates that the arterial supply of the heart, i.e. the length density of arteries Lv (length per unit myocardial volume), decreases during normal growth. Empirically, we found L = constant.LVW-0.28 (r = 0.43, P < 0.01). Previously, we estimated growth rates of b = 0.33 for the total length of left ventricular myocytes and b = 0.71 for the total length of capillaries. Thus, growth of intramyocardial arteries considerably exceeds the length increase of myocytes, but is proportional to the length increase of capillaries. Growth analysis of total mitochondrial volume using historical data of our group revealed proportionality to arteries, as well (b = 0.76). This indicates that growth of arteries and capillaries may be determined by oxygen consumption.

Animals↗
PubMed1992

Effects of nifedipine and moxonidine on cardiac structure in spontaneously hypertensive rats. Stereological studies on myocytes, capillaries, arteries, and cardiac interstitium.

Light and electron microscopic stereological studies were performed on the myocardium of spontaneously hypertensive rats (SHR-SP) before and after treatment with nifedipine (27 mg/kg body weight/day) and the antisympathotonic agent moxonidine (8 mg/kg body weight/day). The treated groups were compared with nontreated SHR-SP and normotensive WKY (n = 10 in each group). At the beginning of therapy (when the male SHR-SP were 6 months old), blood pressure was increased and left ventricular hypertrophy had developed whereas pathologic changes of myocardial structure were not observed. After 3 months, the nontreated hypertensive rats showed cardiac fibrosis, activation and proliferation of interstitial cells, wall thickening of intramyocardial arteries, reduced capillarization as well as focal degeneration of myocytes at the ultrastructural level. Both treatments showed similar effects on blood pressure, degree of hypertrophy, and cardiac structure. Blood pressure as well as the degree of hypertrophy were significantly reduced. As far as myocardial fibrosis, capillarization, and regressive changes of myocytes are concerned a complete normalization was observed. Furthermore, nifedipine enhanced capillary supply beyond the normal level by induction of capillary neoformation. Microarteriopathy and activation of nonvascular interstitial cells (first step in development of interstitial myocardial fibrosis) were significantly suppressed by therapy, but the level of the normotensive control could not be maintained. Additional experiments with a low dose combination therapy of nifedipine and moxonidine that did not reduce blood pressure provided evidence that hypertension is an important determinant of the alterations of intramyocardial arteries, but not of cardiac interstitial fibrosis.

Animals↗
PubMed1992

Effect of early onset angiotensin converting enzyme inhibition on myocardial capillaries.

We investigated the preventive effects of long-term treatment with the angiotensin converting enzyme inhibitor ramipril on myocardial left ventricular hypertrophy and capillary length density in spontaneously hypertensive rats. Rats were treated in utero and subsequently up to 20 weeks of age with a high dose (1 mg/kg per day) or with a low dose (0.01 mg/kg per day) of ramipril. Animals given a high dose of ramipril remained normotensive, whereas those given a low dose developed hypertension in parallel to vehicle-treated controls. At the end of the treatment period, converting enzyme activity in heart tissue was inhibited dose-dependently in the treated groups. Both groups revealed an increase in myocardial capillary length density together with increased myocardial glycogen and reduced citric acid concentrations. Left ventricular mass was reduced only in high dose- but not in low dose-treated animals. Our results demonstrate that early onset treatment with a converting enzyme inhibitor can induce myocardial capillary proliferation, even at doses too low to antagonize the development of hypertension or left ventricular hypertrophy. We hypothesize that potentiation of kinins is responsible for this effect, probably by augmenting myocardial blood flow, which is a well-known trigger mechanism of angiogenesis in the heart.

Administration, Oral↗
PubMed1991

Effects of nifedipine and moxonidine on cardiac structure in spontaneously hypertensive rats (SHR)--stereological studies on myocytes, capillaries, arteries, and cardiac interstitium.

Light and electron microscopic stereological studies were performed on the myocardium of spontaneously hypertensive rats (SHR) before and after treatment with nifedipine (27 mg/kg b.w./day) and the sympatholytic agent moxonidine (8 mg/kg b.w./day). The treated groups were compared with nontreated SHR and normotensive WKY (n = 10 in each group). When the therapy was started in 6-month old male SHR, blood pressure was increased and left ventricular hypertrophy had developed. On the other hand, pathologic changes of myocardial structure were not observed. After 3 months, the nontreated hypertensive rats showed cardiac fibrosis (volume density of fibrosis + 45%), activation and proliferation of interstitial cells (volume density of nonvascular interstitium + 240%), media hypertrophy of small arteries (total volume of arterial media in the left ventricle + 180%), reduced capillarization (length density of capillaries--11%), as well as focal degeneration of myocytes at the ultrastructural level. Both treatments showed similar effects on blood pressure, degree of hypertrophy, and cardiac structure. Blood pressure as well as degree of hypertrophy were significantly reduced (relative left ventricular weights: --25% and --16%). As far as myocardial fibrosis, capillarization, and regressive changes of myocytes are concerned a complete normalization was observed. Microarteriopathy and activation of nonvascular interstitial cells (first step in development of interstitial myocardial fibrosis) were significantly suppressed by therapy (total media volume --40%, volume density of nonvascular interstitium --38%), but the normal level of the normotensive control could not be maintained (+ 70%, + 111% vs WKY). This may be due to the slightly elevated systolic blood pressure despite therapy (+ 25%, vs WKY) or to hormonal factors in SHR which are independent of blood pressure. Since nifedipine and moxonidine are pharmacologically different drugs with different effects on sympathetic activity, one may cautiously conclude that increase in blood pressure itself is an important determinant of arterial, interstitial as well as myocellular alterations which are related to the pathogenesis of hypertensive heart muscle disease.

Animals↗
PubMed1991

Stereology, flow cytometry, and immunohistochemistry of follicular neoplasms of the thyroid gland.

A retrospective analysis of surgically resected thyroid cold solitary nodules was performed by stereology, DNA flow cytometry, and immunohistochemistry in 15 follicular adenomas and 15 well-differentiated follicular carcinomas to determine if a differential diagnosis of both follicular neoplasms can be done exclusively from cytologic criteria. Between 150 and 200 tumor cell nuclei (TCN) were studied per case for their TCN profile area, perimeter, and density, as well as for stereologic estimates, including the new parameter, volume-weighted mean particle volume (Vv). Flow-cytometric analyses included measurement of the DNA index and the percentage of cells in S phase and G2M phase. The same tumors were examined for the expression of thyroglobulin and the intermediate filaments vimentin and keratin. Follicular adenomas and follicular carcinomas did not show any significant differences in stereologic estimates related to TCN size. Both groups included similar proportions of diploid and aneuploid neoplasms. Aneuploid follicular neoplasms showed a significantly greater area, perimeter, and volume of TCN as compared with diploid tumors, regardless of their histologic diagnosis. Follicular adenomas and follicular carcinomas expressed a similar staining pattern for the tested immunoreagents, with a few cases coexpressing vimentin and keratin. From our results, a differential diagnosis of follicular neoplasms cannot be performed on the basis of cytologic aspirates exclusively. Infiltration of capsula or vessels remains the only safe indicator of malignancy in the absence of metastases. The lack of cytologic differences suggests that some follicular adenomas are preinvasive carcinomas, not yet showing infiltrative growth at the time of resection.

Adenocarcinoma↗
PubMed1990

[Differential diagnosis of follicular neoplasm of the thyroid].

Fifteen resected follicular adenomas and 15 well-differentiated follicular carcinomas of the thyroid gland were analysed to determine whether a differential diagnosis of both "follicular neoplasms" can be performed by cytological criteria exclusively. 150-200 tumor cell nuclei (TCN) were studied per case for their TCN profile area, perimeter, density and for stereological estimates including the new parameter Vv, volume-weighted mean particle volume. Flow-cytometric analyses included measurement of the DNA index, the percentage of cells in S-phase and in G2/M phase. Follicular adenomas and follicular carcinomas did not show any significant differences in stereological estimates related to TCN size. Both groups included similar proportions of diploid and aneuploid neoplasms. Aneuploid follicular neoplasms showed a significantly greater area, perimeter and volume of TCN as compared to diploid tumors, regardless of their histological diagnosis. From our results a differential diagnosis of follicular neoplasms cannot be performed on the basis of cytological aspirates exclusively. Infiltration of capsula or vessels remain the only safe indicators of malignancy in the absence of metastases. The lack of cytological differences provides evidence that some follicular adenomas are preinvasive carcinomas, not yet showing infiltrative growth at the time of resection.

Adenocarcinoma↗