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Biomedical subjects

W Sandritter

Publications and source records attributed to W Sandritter.

At least 73 records · Page 4Linked to original sources
PubMed1976

The significance of random sample size in flow-through photometric prescreening in cervical cytology.

The determination of nuclear DNA content by flow-through photometry is employed as a prescreening procedure in cervical cytology. The goal of a prescreening procedure is to obtain the smallest possible number of false negative findings with an economically acceptable number of false positive findings, which must be retested. False negative findings result from the often low relative frequency of atypical cells in a mixed population of normal and atypical cells. Only between 10,000 and 50,000 cells are contained in a random sample from the total suspended smear material. It was the purpose of this study to investigate whether a flow-through photometric study of the entire suspension and thus the larger absolute frequency of atypical cells mught lead to a decrease in false negative results. Flow-through photometric evaluation of the entire smear material is not superior to measurement of a random sample of 10,000-50,000 cells. 1. The relative frequency of atypical cells is unchanged, and thus also the proportion of false negative findings. 2. The number of false positive findings increases by 10% due to the inclusion of aggregates at the bottom of the preparation. 3. The measuring time is increased 10-fold, thus making the prescreening procedure uneconomical.

Cell Count↗
PubMed1976

DNA and the cell cycle.

The cell cycle and its significance for pathology is reviewed. The molecular basis and questions of regulation in the cell cycle are discussed, along with deviations from the normal cycle in the form of polyploidy formation and aneuploidy in tumor cells. Automated prescreening processes may play a role in the future in daily routine diagnosis. Methods of cytophotometry with the possibility for objective pattern recognition will become significant in pathology in many ways, both in research and in routine work.

Aneuploidy↗
PubMed1976

Transmission and scanning electron microscopy of experimentally induced thyroid tumors in rats.

Irradiation of the neck region of 10 days old Wistar rats with 300 rads X-rays and their subsequent treatment with MTU leads to the development of thyroid tumors. The ultrastructure of the thyroid tumors induced was studied by transmission (TEM) and scanning electron microscopy (SEM). In follicular carcinomas, cylindrical or high columnar cells with abundant microvilli, well-developed ergastoplasmic reticulum and a hypertrophied Golgi complex predominate. The cytoplasm of the tumor cells of papillary carcinomas was composed of large pleomorphic cisternae, irregular in shape mitochondria, dense bodies, phagolysosomes and lamellar or multivesicular structures. Scanning electron microscopy revealed in the control animals a regular pattern of thyroid follicles tied to each other by tissue bridges and covered by set of blood and lymph vessels. The relief of the follicular carcinomas was irregular indicating follicles different in size and shape. The internal surface of the neoplastic follicles was also irregular as result of deep invaginations and intrafollicular cell growth. The apical region of the normal and neoplastic thyroid follicular cells was covered with abundant microvilli protruding into the colloid.

Adenocarcinoma↗
PubMed1976

Effects of methylcholanthrene on epidermal growth regulators. II. Variations in the S-factor.

There is increasing evidence to support the existence of tissue-specific growth-inhibitory chemical substances which can be found in extract homogenized cells. In the epidermis, two such tissue-specific factors (which also have cell-cycle specificity) have been found. These factors act specifically on different phases of the cell cycle (epidermal G1 and G2 chalones, respectively). This paper concerns a study of the effect of 20-methylcholanthrene on the epidermal G1 chalone. The variations in epidermal G2 inhibitor after such treatment were described in a previous paper. Hairless mice received a single topical application of 0.2 ml 0.5% solution of the carcinogen. The short time effect of the carcinogen application on epidermal DNA synthesis was first studied. Other groups of carcinogen-treated mice were then killed at similar time intervals, and the treated area of skin was homogenized and extracted with water. The inhibitory effect of these extracts on normal epidermal G1 cells was assayed in normal hairless mice. The obtained inhibition was registered as an expression of G1 inhibitor concentration in the skin extracts. The first experiment confirmed that a single carcinogen application provokes a short block in epidermal DNA synthesis, followed by a high, biomodal peak of increased activity with the first and maximum peak on day 2, and a smaller peak on day 8 after treatment. The second experiment showed that the content of G1 chalone in the skins of treated animals varied inversely to the alterations in epidermal DNA synthesis, revealing almost no chalone activity on day 2, and reduced chalone activity on day 8.

Animals↗
PubMed1976

[Influence of autolysis on the quantitative cytoarchitecture of rat hepatocytes. (An ultrastructural morphometric study) (author's transl)].

INTRODUCTION: Autolysis is very often a reason for cell damage and is also super-imposed on many other cell damages. Already one hour of autolysis causes serious changes in cell metabolism, which can be demonstrated morphometrically. MATERIAL AND METHODS: Experiments were made with 10 male adult Wistar rats. 5 animals were for control purposes and 5 animals had to undergo a 1-hour's autolysis. The morphometric analysis of the liver parenchymal cells was based on the information of Weibel et al. (1968) with the help of a computer program. RESULTS AND DISCUSSION: The consequence of the drop in energy caused by autolysis is an enlargement of the liver cell which is possibly due to a breakdown of the energy-dependent ionic pumps. One of the earliest observable cell changes is a so-called "Kernwandhyperchromatosis" and chromatin condensation within the nuclei, whereby the Kernwandhyperchromatosis is seen to be a direct consequence of the increase in lactate and decrease of pH. ATP-sufficiency causes a disturbed function of mitochondrial membranes. The microchondria are swollen, the number of mitochondrial grana is clearly reduced. An enlargement of the mitochondrial outer membrane takes place by folding while the surface of mitochondrial cristae remains unchanged. As a consequence of the altered membrane activities also the peroxisomes swell at reduced numerial density. At unchanged total volume of RER the surface of the granulated membranes of the RER decrease by 50%. This decrease caused by ribosome detachment of the granulated membranes corresponds to the enlargement of the degranulated membrane parts of the nedoplasmic reticulum. The vesiculation is caused by an unspecific damage of cytoplasm. While the density of its volume and the membrane surface remain unaltered, the SER also shows a tendency to small vesiculation caused by an unspecific damage of cytoplasm. The increase in number and volume of the lysosomes and vacuoles of unknown origin speaks for a lysosomal activity. The cell compartment responsible for protein synthesis shows the most impressive morphometric and morphologic changes, which eventually can be explained by a decrease of protein synthesis which is needed to obtain enough energy for a well operating physiological equilibrium.

Animals↗
PubMed1976

Effects of D-penicillamine administration to rats, induction of renal changes: preliminary communication.

Oral administration of synthetic D-penicillamine to rats induces alterations of the renal mesangium, apparently without involvement of immune mechanisms. Alterations of mitochondria, especially enlargement, were seen in the proximal tubular epithelium. These results are discussed in the light of recent findings in "penicillamine" nephritis and diseased human kidneys in general.

Animals↗
PubMed1976

[Use of alloplastic material on the extrahepatic bile ducts].

Dogs (20 kg body weight) were laparotomized and the choledochous duct was ligated. Pre- and postoperative laboratory-parameters such as bilirubin, GOT, GPT, and alcaline phosphatase were controlled. Then, 8 days later, a patch-widening-plasty was performed after incision of the stenosis in 10 dogs. In the 10 other dogs the stenosis was resected and the defect was bridged over with a Teflon prosthesis. A few days later laboratory parameters became normal. Histologic investigation showed that after 4 weeks the Teflon prosthesis was covered with a bile duct-epithelial layer. In one of 3 patients with normal laboratory findings who have a Teflon patch, the operation took place 2 years ago.

Alkaline Phosphatase↗
PubMed1975

Mitochondriosis of the hepatocytic cytoplasm in rachitic rat liver after calcitonin-treatment (a cytophotometric and morphometric study).

A calcium-rich rachitogenic vitamin-D deficiency and additional doses of calcitonin cause serious changes in cell structure and metabolism, which can be demonstrated by cytophotometry and morphometry. The experiments were made with 9 male juvenile Wistar rats. 6 animals were kept on a vitamin-D deficient diet for 6 weeks and 3 of these animals got injections with salmon-calcitonin S.C. during the last 14 days every second day. The remaining 3 animals, fed with altromin-R standard diet were kept for control purposes only. The morphometric analysis of the liver parenchymal cells was based on the statements by Weibel and the cytophotometric examinations were made according to the Sandritter technique. As a consequence of the altered metabolic condition a great volume reduction of cells and cell nuclei is found in the animals with vitamin-D deficiency, which were treated with calcitonin. In comparison with the control animals the hepatocytes show hardly any tetraploid nuclei, which points to an inhibited polyploidization. The cytoplasm shows an oncocytic transformation with megamitochondria. As reason for this mitochondriopathy an extreme and abnormal growth as well as a mutation of the mitochondrial genom are under discussion. Furthermore the total endoplasmic reticulum (volume and membrane surface), the peroxisomes and the ribosomes are strongly reduced. Due to the serious cell injury the other organelles are also reduced in number and volume, which points to a chronic hypocalcemia.

Animals↗
PubMed1975

[Influence of hypothyreodism on the quantitative Karyo- and cytoarchitecture of rat hepatocytes. (A morphometrical and cytophotometrical study on rat hepatocytes 3 weeks after thyreoidectomy) (author's transl)].

INTRODUCTION: Thyroid hormoned influence the quantitative cytoarchitecture of hepatocytes by stimulating the membrane synthesis of mitochondria and ergastoplasm. The cellular and nuclear changes produced by thyroidectomy were analysed cytophotometrically and morphometrically. MATERIAL AND METHODS: 21 days after thyroidectomy the liver tissues of 10 male Wistar rats were examined. 5 sham-operated animals served as controls. All rats received Altromin-R-standard diet. The cytophotometric analysis is based on the method described by Sandritter. The morphometric study was carried out following Weibel's methods. RESULTS AND DISCUSSION: As a consequence of the changed cellular metabolism, smaller hepatocytes and nuclei (but larger nucleoli) are found in the hypothyroid rats. As compared with controls, hepatocytes hardly show tetraploid nuclei, which is due to inhibited polyploidisation. The mitochondrial content has become considerably smaller in the hypothyroid hepatocytes. The cristal membranes, the mitochondrial and peroxysomal volume per hepatocyte show a similar reaction pattern, which is considered to be a sign of reduced cellular metabolism. The volume loss of the ergastoplasm confirms this assumption.

Animals↗
PubMed1975

Güther Beneke.

Explore the source record for details and available documents.

Germany, West↗
PubMed1975

DNA measurements on cell nuclei of normal, proliferating and neoplastic thyroid tissues in rats.

Nuclear DNA content was measured in 3 normal, 9 hyperplastic and 16 neoplastic rat thyroid glands. Thyroid hyperplasia and tumor growth were induced after treatment of the animals with X-rays and methylthiouracil. In the control animals only diploid thyroid epithelial cells were observed. At the stages of diffuse and nodular thyroid hyperplasia, the total DNA content per nucleus indicated for a diploid chromosome number and only a few cells were hyperdiploid. In the thyroid adenomas and carcinomas a scattering of the diploid region and an increase in the number of hyperdiploid cells was found. Among the various types of thyroid tumors neither difference in the number of hyperdiploid cells, nor typical pattern of distribution of these cells in the histogram was found. The increased number of hyperdiploid cells in the hyperplastic and neoplastic thyroids suggest an increase in the proportion of the cells entering the cell cycle and does not indicate for appearance of a neoplastic stemline.

Adenocarcinoma↗
PubMed1975

[Intravital microscopy and post mortem histology of burn shock in rabbits (author's transl)].

This paper describes results of intravital microscopic observations of the mesenteric blood and lymph vessels of the rabbit. 20% of the surface of the skin of these rabbits were burned. Immediately after producing the shock, general unspecific symptoms were seen: decrease of circulatory flow, aggregates of erythrocytes. Specific alterations consisted in leukocyte sticking, platelet aggregation, hemolysis and stasis. Vascular spasm and hemorrhage were conspicuously absent. These microcirculatory features were compared with those of different forms of shock. There was a striking similarity with the characteristics of the burn shock with the endotoxin shock. On the other hand hemorrhagic and traumatic shock exhibited similar phenomena, thus forming a second distinct group of shock as seen from a microcirculatory point. Differentiation between the groups is only possible from the specific features of microcirculation failure. These results confirm the view point, that different forms of shock evoke different pathological reactions in the terminal vascular bed.

Animals↗