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Biomedical subjects

T Szepesi

Publications and source records attributed to T Szepesi.

At least 19 recordsLinked to original sources
PubMed1999

Sex differences on the hand mental rotation task for 9-yr.-old children and young adults.

The Hand Mental Rotation task is assumed to activate an egocentric spatial reference frame to realize mental rotation. This study presents significant sex differences in hand mental rotation performances between men and women (n = 23 and 25, respectively; age: 20.7 yr.). Differences in hand mental rotation in school girls and boys (ns = 48 and 41, respectively; age: 9 yr.) were not significant. Our results suggest that the change in sex differences in egocentric mental rotation may occur with developmental change. This requires further testing with a larger sample so testing can occur at several ages between 9 and 20.7 years.

Adult↗
PubMed1991

CA15.3, MCA, CAM26, CAM29 are members of a polymorphic family of mucin-like glycoproteins.

The monoclonal antibodies that define the tumor markers CA15.3, MCA, CAM26 and CAM29 were found to react with coexisting epitopes present on mucin-like glycoproteins. Despite their immunologic relationship, the markers showed distinct concentration levels in various body fluids. Particularly, MCA and CAM26 were high in urine and amniotic fluid. Sera collected from pregnant or lactating women and especially human milk samples contained considerable amounts of CAM29 and MCA, but comparably small quantities of CAM26 and CA15.3. The concentrations of CA15.3, MCA, CAM26 and CAM29 were correlated in serum samples from patients with metastatic breast cancer. The discrepancy between immunologic relationship and dissimilar biologic behavior could be explained by a limited coexistence of epitopes on subsets of heterogeneous polymorphic mucins. All mucin markers which were investigated showed improved sensitivity for metastatic breast cancer compared with the established marker CEA.

Adolescent↗
PubMed1991

Early indicators of response to accidental radiation exposure and the relevance for clinical management strategies.

In the development of clinical strategies to manage radiation accident casualties, the medical doctor in charge should be encouraged to use a "decision tree" to establish by a "sequential diagnosis procedure". This should be done within the first few days after exposure to determine whether or not a spontaneous recovery of hemopoietic function can be expected. With the assistance of a computer simulation model it appears possible to relate certain granulocyte response patterns to the extend and quality of damage caused in the hematopoietic stem cell pool. The determination of this damage is of great importance because it quantifies the strain inflicted upon the hemopoietic system by radiation exposure. It must be remembered that some stem cells are intact or are able to repair the damage completely. These stem cells serve as the ultimate source of hemopoietic recovery. The other stem cells that are left with the restricted hematopoietic potential are the source for the so called abortive recovery. On this basis it must be recognized that the day-to-day detailed analysis of documentation of blood cell changes for the first 5-10 days after exposure is of critical importance in order to be able to answer the question whether a spontaneous hemopoietic recovery can be expected or not. If the stem cell pool is sufficiently damaged (less than 6-8 in 10,000 stem cells) then one can expect a particular constellation of blood cells around day 5-7 characterized by severe granulocytopenia, severe lymphopenia and beginning thrombocytopenia. This blood cell response pattern is indicative of an irreversible stem cell damage. In this case, a transplantation of stem cells may well be life saving if done using the criteria developed for the treatment of severe aplastic anemia by bone marrow transplantation including an appropriate conditioning regimen for immune suppression.

Accidents↗
PubMed1990

Prediction of clinical outcome of radiation accident victims.

On the basis of the analysis of more than 350 individuals that were exposed to ionizing radiation in the course of more than 25 radiation accidents reported world wide since 1945, a biomathematical computer model was developed that simulates the pattern of granulocyte changes seen. It allows one to calculate the number of stem cells remaining intact to initiate recovery. It is shown that the major question to be asked is whether a spontaneous stem cell recovery can be expected or not. This question can be readily answered within 3-5 days after radiation exposure on the basis of the constellation of hematopoietic findings and devised stem cell pool size calculations.

Accidents↗
PubMed1990

[The effect of 5-fluorouracil on the radiosensitivity of granulocytopoietic stem cells in the bone marrow and the blood].

The radiation tolerance of haematopoietic stem-cells, originating from blood and bone marrow, after exposure to 5-Fluorouracil (5-FU) was investigated. The CFU-C Colony Formation Test was used to determine the surviving fraction of cryopreserved mononuclear bone marrow and blood cells, after incubation in culture medium containing 1 ng/ml 5-FU for 24 hours. With the same assay system we determined the radiation tolerance of peripheral CFU-C from three patients before and after 5-FU radio-chemotherapy (1000 mg/m2/24 h per day for four days), while the influence of the small radiotherapeutic treatment volume was neglected. Neither in the in vitro experiments nor in the patients we found a significant variation of the dose-survival curves with or without 5-FU. So it is concluded, that the enhanced myelodepression of 5-FU combined with radiation may be due to an additive effect or by effects on the microenvironment or on the pluripotent stem cell system.

Combined Modality Therapy↗
PubMed1989

[Dose, radiation effect and initial symptoms following unexpected whole body irradiation: an analysis of 19 accidents].

The radiation induced effects on the haemopoietic system and the human body after acute unexpected whole body irradiation are manifold. Therefore it is meaningful to incorporate the scientific foundations of radiation effects in the available knowledge about the consequences of radiation exposure. From this aspect the present paper evaluates 19 acute radiation accidents which were published between 1945 and 1986 in the scientific literature involving about 597 individuals. Even in the case of an uncomplicated radiation effect the physician must not rely on the estimated physical dose because it does not or does not necessarily correlate with the different course of events taken by the individual categories of the acute radiation syndrome. In fact, the dose is of minor importance to the physician because as a rule it can only be determined too late due to the complex parameters. The classification, therapy and prognosis of the accident victims is largely governed by the pathophysiology which results from the random probability of the cell killing mechanisms by radiation, inhomogeneous dose distribution and the scattered distribution of the haemopoietic system in the human body. The fact that in the case of accidentally induced total body irradiation there is only inhomogeneous distribution of radiation dose is a life-saving factor in most cases. Furthermore, it is pointed out that by means of simple diagnostic methods, e.g. the initial symptoms, the first classification of accident victims is also largely possible without referring to the dose.

Accidents↗
PubMed1989

[Reversible and irreversible damage to hematopoiesis following unexpected whole body irradiation: markers in peripheral blood].

During the past decade worldwide experience concerning radiation accidents demonstrated that the medical diagnosis and therapy of radiation victims has to be reconsidered. This paper describes and analyzes the clinical relevance of one of the most simple diagnostic methods, namely daily monitoring of the characteristic blood cell changes. On the basis of these methods the physician is in the position to decide at an early stage-independently of the physical dose-whether reversible or irreversible damage of the hemopoiesis is present. This is of great importance because the expected clinical development and, thus, the therapy and prognosis are different. The different behaviour of the blood cells depends on their life span, cell kinetics, radiation sensitivity and pathophysiology. Reversible damage (category I-IV) can be recognized at the latest on the 5th-6th day after radiation exposure and, according to the degree, may require supportive therapy. Irreversible damage which can probably be repaired by stem cell transfusion (category V) can also be determined on the 5th to the 6th day after radiation exposure. Irreversible damage without any chance of survival (category VI) can already be diagnosed 24 hours after the radiation event. Reversible and irreversible damage to hemopoiesis with the typical blood cell changes is presented with reference to some patients exposed to ionizing radiation in the Marshall Islands 1954, in Oak Ridge 1958, in Chernobyl 1986, in Los Alamos II 1946 just as III 1958, and in Wood River Junction 1964.

Accidents↗
PubMed1989

Small bowel function after surgery for chronic radiation enteritis.

The retention of the gamma-emitting 75Se-homotaurocholic acid (SeHCAT) after 72 and 168 h was assessed in 10 patients after ileal resection for radiation injury (group I). 6 patients suffering from chronic postirradiation diarrhea (group II) and 6 patients in whom the ileum had been resected for other indications (group III) were also examined. The retention of SeHCAT was abnormally low (less than 50%) in all cases after 72 h and below 20% in 19 out of 21 cases after 168 h. The length of resected small bowel (groups I and III) was inversely related with SeHCAT retention after 72 h (r = 0.63; p = 0.015), but not after 168 h. There was no correlation between the diarrhea score and the extent of bowel resection, SeHCAT retention or xylose absorption. Hydrogen breath test with lactulose revealed a significantly shortened orocecal transit time in group I, compared to groups II and III. Xylose absorption was significantly reduced in patients with positive 5 g xylose-H2 breath test. In groups I and III, however, xylose absorption tended to improve with increasing time interval following resection (r = 0.79; p = 0.003). It is concluded that radiation injury in addition to small-bowel resection contributes significantly to malabsorption and diarrhea in patients after ileal resection for radiation sequelae. The chronic radiation damage seems to act mainly through impaired motility.

Body Weight↗
PubMed1989

MCA, a monoclonal-antibody-defined breast-tumor-associated antigen and its relation to CA 15.3.

A mucin-like carcinoma-associated antigen (MCA) was recently identified on the surface of established breast cancer cell lines by several monoclonal antibodies. The antibody b-12 was used in a sandwich enzyme immunoassay to measure MCA concentrations in serum samples and other biological fluids. The upper limit for noncancerous women and men was 14 U/ml. MCA levels were independent of estrogen or prolaction secretion, 63% of patients with metastatic breast cancer had elevated serum concentrations of MCA. Elevated MCA levels were also associated with cervical, ovarian or endometrial cancer and carcinoma of the prostate. In metastatic breast cancer, MCA and CA 15.3 showed similar sensitivity. Carcinoembryonic antigen levels did not correlate with MCA. Serum concentrations of MCA increased during pregnancy and remained elevated in nursing mothers. Amniotic fluid was found to be rich in MCA. In contrast, CA 15.3 showed only small changes during pregnancy and was low in amniotic fluid. From binding tests with antibodies used in the MCA and CA 15.3 assays, we conclude that the monoclonal antibodies b-12 as well as 115-D8 and DF3 (CA 15.3 assay) recognize coexisting epitopes on mucin-like antigens, which belong to a polymorphic family of glycoproteins suitable for tumor monitoring. Differences in the behavior of MCA and CA 15.3 may emerge from the complexity and heterogeneity of these mucin-like antigens.

Age Factors↗
PubMed1989

[Simultaneous radiation- and chemotherapy (methotrexate and bleomycin) of inoperable malignant oro-facial tumors].

The overall response rate is 65% with 17% CR (medium 56 months) and 49% PR (medium 5 months). The Kaplan-Meier survival plot shows no difference between the previously treated and untreated groups, whereas the kappa 2-analysis indicates a significant advantage for patient with complete response in the previously untreated group (p less than 0.03). Between the different tumor sites and the presence or absence of lymphnodes, there was no significant difference either in survival or in the distribution of the CR, PR and P. The group with bone destruction has a significant shorter median survival time of 9 months versus 15 months in patients with no bone-involvement (p less than 0.03).

Bleomycin↗
PubMed1988

Follow-up of metastatic breast cancer patients with a mucin-like carcinoma-associated antigen: comparison to CA 15.3 and carcinoembryonic antigen.

During a follow-up program, breast cancer patients were monitored with serum analyses of mucin-like carcinoma-associated antigen (MCA), CA 15.3 and carcinoembryonic antigen (CEA). Minimum as well as maximum marker values of the individual patterns were selected for further evaluation. Marker levels of risk patients differed significantly from those of patients with metastases. In several risk patients, elevated marker levels (especially of MCA) preceded clinical diagnosis of metastases for several months. In cases with already diagnosed metastases, sensitivity of MCA was comparable to CA 15.3 or CEA. The type of metastases determined marker sensitivity, concentration and the difference between maximum and minimum values.

Antibodies, Monoclonal↗
PubMed1987

Surgical therapy of radiation-induced small-bowel lesions. Report of 34 cases with a high share of patients with combined chemotherapy.

Operations on irradiation-injured bowel are rare, bear a high postoperative mortality, and the procedure of choice (resection vs bypass) is still controversial. Thirty-seven operations on small bowel for late effects of irradiation in 16 years were analyzed retrospectively. Fifty-one percent of the operations were performed in the last four years. Ovarian cancer treated by a combination of radiotherapy and chemotherapy was the most frequent underlying disease of 20 patients (58%) followed by carcinoma of the cervix (eight [24%] of the patients). The median latent period between irradiation and surgery was eight months after the combined radiotherapy/chemotherapy, and 12 months after radiotherapy alone. Thirty operations (81%) were done for small-bowel stricture, four for fistula, and three for perforation. Bypass was performed in 17 patients and resection in 16. Complications (fistula, peritonitis, perforation) occurred after 13 operations (35%). All three patients who developed peritonitis died (mortality, 8.1%): two after resection and one after bypass. Suture-associated complications occurred in three (23%) of 13 cases after single-layer and in three (35%) of 17 cases after two-layer anastomoses. Ten patients are still alive two to 76 months (median, 32 months) after operation, six of them free of tumor. All are underweight and suffer from diarrhea (four to 12 stools per day). Pernicious anemia developed in all six patients surviving more than two years.

Adult↗
PubMed1986

[Surgical therapy of late radiation sequelae of the gastrointestinal tract].

Fifty-six operations for intestinal complications of radiation therapy were performed in 48 patients at the Second Surgical Clinic, University of Vienna between 1971 and 1985. The lesions were located in the small bowel (n = 32), the colon and rectum (n = 27) and the duodenum (n = 2). The incidence of the operations increased during the fifteen-years-period, 48.2% being performed in the last five years. 96% of the patients were females, the most frequent cause for irradiation was ovarian cancer (39.6%), followed by cervical (27%) and endometrial cancer (16.7%). 20 Patients (39.6%) had also been treated by chemotherapy. Ovarian cancer as underlying disease (56%) and chemotherapy (56%) were more frequent in small bowel lesions, than in other locations. The radiation damage presented as stenoses (n = 38), fistulas (n = 13), perforations (n = 3), one rectal ulcer and one hemorrhagic proctitis. Resection with end-to-end-anastomosis (n = 15) and bypass (n = 14) were the operations most frequently performed on the small bowel, whereas most colonic and rectal lesions were treated by colostomy alone (n = 14). The postoperative course was complicated by fistulas in 7 patients, by peritonitis in 5, by pulmonary embolism in one and duodenal ulcer perforation in another case. Six patients died postoperatively (10.7%), 5 because of peritonitis. After small bowel resection complications occurred in 4 cases, and two (13%) of the patients died. Bypass in small bowel lesions performed as well as resection: 5 complications and one death (7%) occurred. Single layer suture technique performed better than two layer anastomoses. Eighteen operations with single layer anastomoses resulted in 16.7% complications and no death.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗