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Biomedical subjects

B Helpap

Publications and source records attributed to B Helpap.

At least 73 records · Page 4Linked to original sources
PubMed1984

Cytomorphological and histological studies on the urothelium during and after chemoimmune prophylaxis.

During and after chemoimmune prophylaxis with i.v. cyclophosphamide (CTX) and both intravesical and systemic BCG-treatment, the bladder mucosa is prone to morphological changes which might resemble tumor recurrences. Therefore, morphological parameters which can discriminate between treatment effects and tumor recurrences are of interest. In a prospective study, routine cytology, determination of granulocytes, lymphocytes, and macrophages in the urine sediment as well as flow-cytophotometry (FCM) for DNA analysis were performed before, during, and after chemoimmune prophylaxis. In addition, bladder biopsies and all recurrent tumors were histologically analysed. Our results show that FCM is the best method for monitoring the bladder mucosa for recurrent tumors during treatment. After termination of BCG, it takes at least 4 months for cytological normalization to take place. Urine excretion of granulocytes, lymphocytes, and macrophages does not correlate with this process. Histological alterations during treatment are demonstrated; their normalization requires at least 3 months. In 10% of the patients chronic inflammatory lesions ("pseudotumors") develop.

BCG Vaccine↗
PubMed1984

Suppression and acceleration of DNA synthesis in megakaryocytes after partial hepatectomy.

3H-thymidine labelling indices of megakaryocytes were determined in the spleen and bone marrow of normal, sham-operated and partially hepatectomized rats. Compared with controls, the labelling indices were much lower in megakaryocytes but much higher in other cells such as erythroid cells or proliferating duodenal mucosal cells when measured in rats from 12 to 36 h after partial hepatectomy. From 48 to 72 h after hepatectomy the labelling indices of megakaryocytes became higher than control values. On the other hand the labelling indices of megakaryocytes from 12 to 36 h after sham operation were higher than controls. The accelerated DNA synthesis of megakaryocytes after sham operation was considered to reflect the additional DNA synthesis in this cell line which leads to an increase of the average ploidy level. The initial decrease in labelling indices of megakaryocytes after partial hepatectomy did not occur if serum from normal or thrombocytopenic rats was injected. These findings suggest that the liver may produce a humoral factor which influences the so-called endomitosis of megakaryocytes.

Animals↗
PubMed1984

Thymus in myasthenia gravis: a light and electron microscopic study of a case with thymic follicular hyperplasia.

The present study has focused mainly on microenvironmental aspects of the thymus from a 17-year-old female patient suffering from myasthenia gravis. The most striking lightmicroscopic feature was again the well known presence of lymphoid follicular hyperplasia. Ultrastructurally, the configuration, cellular composition and fine structure were to a large extent the same as in other, peripheral lymphoid organs. Cells showing the typical morphologic characteristics of fibroblastic reticulum cells, which are most probably precursors of dendritic reticulum cells, were observed within germinal centers. Additionally the morphology of the unaffected medulla and corticomedullary region was studied, thereby paying particular attention to the structural changes of interdigitating cells. These contained frequently Birbeck granules, which have not been described before in human thymus.

Adolescent↗
PubMed1984

Cell proliferation and growth of gastric carcinoma induced in inbred Wistar rats by N-methyl-N'-nitro-N-nitrosoguanidine.

Gastric carcinoma was induced in inbred Wistar rats by p.o. administration of N-methyl-N'-nitro-N-nitrosoguanidine for 25 weeks, and cell proliferation and growth of the gastric carcinoma in an incipient stage were studied. A microscopic cancer was found by 24 weeks, and macroscopic cancers were found after 27 weeks. All the cancers were a single lesion located at the midpoint of the lesser curvature of the stomach. Histologically, they were tubular adenocarcinomas. The mucosal changes predisposing to the development of carcinomas were focal erosions and dysplasias confined to the midpoint of the lesser curvature. The malignant transformation appeared to occur in the dysplastic cells of the eroded mucosa by 17 to 18 weeks after N-methyl-N'-nitro-N-nitrosoguanidine treatment. Following the malignant change, the labeling indices of the tissues with [3H]thymidine decreased, suggesting an elongation of cell cycle time. By repeated injections of [3H]thymidine, a time required for all the cancer cells to enter S phase (reflecting the maximum cell cycle time) was estimated to be about 3.5 days. This gave a theoretical doubling time for the gastric cancers. On the other hand, from the temporal observations of tumor volumes, it was shown that the gastric cancers in an incipient stage underwent exponential growth with a doubling time of 14 days. The difference between the theoretical and actual doubling time might reflect a cell loss rate in the cancer tissue.

Animals↗
PubMed1983

The morphological consequences of thermosurgery.

Immediately after electric coagulation or laser surgery, black-brown carbonizations were observed on the surface of different human tissue biopsies and in the experimental studies of rat organs. In specimens of liver, urinary bladder, and prostate coagulation necrosis developed, followed by a cell-rich granulation tissue with giant cells of the foreign body type. More than 3 months after the thermoinjury the granulomas could still be demonstrated in the tissue. After 6-8 weeks postoperatively (p.o.) a fibrous scar tissue began to develop. The number of lymphocytes in the central T-dependent peripheral lymphatic sheaths (PALS) of the spleen and their labeling index decreased within the first 2 days after thermoinjury followed by a slight hyperplasia after day 5. This initial T-cell alteration may reflect the clinico-serologic finding which shows that after skin burn a temporary reduction of the cell-mediated immune defense mechanism of the organism is observed. Compared with wound healing after scalpel or cryosurgical injuries, the delayed wound healing after thermosurgery may be caused by the alteration of the lymphoid system due to a disturbed co-operation of T- and B-lymphocytes with macrophages.

Animals↗
PubMed1983

[Is tubal sterilization with the Tupla-clip a reversible method?].

Between 1976 and 1981 402 tubal sterilizations were performed with Tupla-clip most of them by laparoscopic application. 11 tubes were removed between 15 and 47 months following the sterilization with the Tupla-clip. The local changes both macroscopically and microscopically to the tupla-clip were evaluated. The possibility of tubal patency following removal of the clips was tested by carbon dioxide pertubation. The tubal-occlusion with the tupla-clip is definitive since all tubes had a fibrous tissue strand where the clip had been applied which still carried blood vessels. No tube was patent with the carbon dioxide pertubation. The intra-operative testing of correct application of the clip and the documentation of this correct application is again mentioned. This is especially important in view of the recent judgements of the federal supreme court regarding liability in failed tubal sterilizations. The excellent chance of reversal by tubal anastomosis and the 100% success rate of this method of sterilization within the 6 years under observation will increase the acceptance of the tupla-clip as a method for tubal sterilizations.

Female↗
PubMed1983

[Comparative histologic studies following esophageal varices sclerosing with different substances].

Sclerosing varices of the lower esophagus by endoscopic injection of phenol-peanut oil or ethoxysclerol into the submucosal tissue induces inflammatory changes of varying degree. The process of inflammation leads to formation of connective tissue surrounding and protecting the varices, or to obliteration of these vessels. Phenol-peanut-oil induces a rather mild inflammatory process which contains many macrophages and runs a slow course, leading to fibrosis and sclerosis without complications worth mentioning. Ethoxysclerol on the other hand can induce suppurating, almost phlegmonous inflammation; complications like mediastinitis and pleural exsudates are definitively more common than after injection of phenol-peanut oil. Life threatening situations and death may occur after previous treatment by balloon compression and subsequent sclerosing procedures. Therefore, treatment of esophageal varices by sclerosing procedures should only be done, if the esophageal wall has not been altered by mechanical therapeutic measures.

Esophageal and Gastric Varices↗
PubMed1983

Should treatment of highly differentiated thyroid carcinoma be conservative?

On the basis of three selected cases (one with clinically occult follicular and two with metastatic papillary carcinoma) the necessity of a comprehensive therapeutic concept even in highly differentiated thyroid cancer is stressed. Thyroid tissue and regional metastases should be eliminated by surgery, followed by radioiodine therapy in any event. Radiation teletherapy should be reserved to patients with invasive tumor growth exceeding the organ capsule, with lymph node metastases, and with massive angioinvasive growth.

Adenocarcinoma↗
PubMed1982

[Grading and staging of urinary bladder carcinomas (author's transl)].

In a retrospective study, staging and grading of 2085 primary and recurrent urinary bladder carcinomas were determined according to WHO and UICC rules. Of the carcinomas 51% were papillary, 23% solid and 26% partly papillary and partly solid. 46.2% of carcinomas were correspondent to malignancy grade I, 37.7% to grade II and 16.1% to grade III. The depth of invasion was the greater the less the degree of differentiation. The uncorrected recurrence rate of carcinoma was 14.9%, 28% of the recurrences showed an increase in malignancy grade and (or) depth of invasion. The recurrence rate fell within the first three years from 76.8% to 8.2%. In addition, there was a high degree of coincidence between carcinoma grade III and severe urothelial dysplasia. The diagnosis of severe dysplasia is an indication for frequent cystoscopic and bioptic checks. Since the biological significance of urinary bladder carcinoma depends not only on the degree of malignancy but also on the depth of invasion and the readiness of carcinoma towards invasion, it is necessary for successful prospective studies, designed to evaluate the course of urinary bladder carcinoma and their therapeutic response, to incorporate exact staging and grading.

Adult↗
PubMed1982

Electron-microscopic study of the development of the periarteriolar zone in splenic white pulp of rats.

To obtain more information concerning the origin of interdigitating cells, the postnatal development and morphology of the periarteriolar lymphatic sheath in splenic white pulp of rats was investigated by light- and electron-microscopy. Special attention was paid to the ontogeny of interdigitating cells. The spleens of the animals were studied in the age range from 1 h to 28 days after birth. The splenic white pulp of neonatal rats consists only of a few reticuloblasts, which are concentrically arranged around central arterioles. After 21 h an increase in promonocytes and monocytes was noted. Between the fifth and seventh postnatal day monocytogenic cells with a light and almost translucent cytoplasm appear, which display long cytoplasmic projections between the adjacent cells. Neighbouring lymphocytes often insert finger-like processes into the invaginated cellular membrane of these transitional forms. This intimate cellular contact is supported by zonulae occludentes. These cells represent transitional forms between monocytes and interdigitating cells. From seven days of age onwards typical interdigitating cells were present as in adult animals. After the differentiation into an inner and outer periarteriolar lymphatic sheath, the T-cell-dependent area of splenic white pulp has attained its adult appearance and further changes are not to be expected. On the basis of these findings, it is highly probable that interdigitating cells develop via transformation of monocytes.

Animals↗
PubMed1982

Regeneration of endocrine cells in the stomach.

A mucosal defect was produced by cryosurgery in the antral and the fundic wall of the rat stomach, and regeneration of gastric endocrine cells was studied 50, 100 and 200 days after operation. Fifty days after the operation, the mucosal defect was completely covered with regenerated epithelium. The regenerated mucosa both in the antral and in the fundic region consisted of mucinous glandular structures. The regenerated mucosa in the corpus remained pseudopyloric in type even 200 days after operation. Regardless of the time after operation, regeneration of endocrine cells was always observed. We could identify G cells and EC cells in the regenerated mucosa of the antrum, and EC cells, A cells and AL cells in the regenerated mucosa of the corpus, respectively. By electron microscopy, endocrine-exocrine cells were frequently encountered. These cells had two different types of intra-cytoplasmic granules; one was an endocrine-specific, small electron-dense granule, and the other a large, lucent mucin droplet-like granule. These findings indicate that the endocrine cells of the stomach are formed from endodermal precursor cells.

Animals↗