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Biomedical subjects

J Frühling

Publications and source records attributed to J Frühling.

17 recordsLinked to original sources

Monitoring of radiotherapy-induced morphonuclear modifications in the MXT mouse mammary carcinoma by means of digital cell image analysis.

The present work deals with the characterization of the morphological changes induced by ionizing radiation on MXT mouse mammary cancer cell nuclei. The monitoring of the radiotherapy-induced morphonuclear modifications was carried out by means of digital cell image analysis, which made it possible to compute morphometric (nuclear area), densitometric (nuclear DNA content) and textural (chromatin pattern characteristics) parameters assessed on Feulgen-stained nuclei. The biological material was obtained from serial fine needle-aspirations performed on control tumors and 2Gy and 8Gy irradiated tumors. Digital cell image analyses were assessed at the 7th, 18th, and 28th days-post irradiation. We showed that radiotherapy induced specific morphonuclear modifications that appeared in a dose-dependent and time-dependent manner. The 2Gy and 8Gy radiotherapy doses led to an increase in the mean nuclear area value, this feature being observed at both the 1st and the 4th week post-irradiation. The resultant effect on the chromatin pattern characteristics corresponded to a decrease in overall condensation level as compared to the control cell nuclei. Finally, the mean nuclear DNA content increased at the 1st week post-irradiation, but decreased at the 4th week post-irradiation as compared to the MXT control tumor. Computerized cell image analysis, therefore, appears to be a useful tool in helping to monitor the radiotherapy-induced effects that occur in neoplastic cell nuclei and which can be observed by means of optical microscopy.

Animals

Influence of hormono- and/or chemotherapy on the MXT mouse mammary tumor as monitored by 31P MRS.

We describe the early in vivo modifications that occurred in the MXT mouse hormone sensitive mammary tumor following various treatments which were monitored by 31P NMR spectroscopy. The MXT mouse mammary tumor was subjected to clinically relevant low-dose chemotherapy, i.e. seven cycles of 20 mg/kg cyclophosphamide (CPA) with or without an attempt at estrogenic cell recruitment prior to the CPA treatment. NMR measurements were begun at the end of the CPA treatment in order to evaluate the remaining 'long-term' chemotherapy-induced modifications within the MXT tumors. Statistical analyses performed on the 31P NMR parameters revealed that treatment had induced significant effects on bATP/PCr, Pi/PCr and PME/PDE only, with PCr being the most discriminating index. Its presence within MXT tumors was verified by means of an analysis of perchloric extracts. The results indicate a relative decrease of PME/PDE and a better conservation of PCr within the CPA-treated group as compared to the control one. This feature appeared even prior to any macroscopic modifications, as was the case within the group which contained tumors smaller than 120 mm2, and where no significant differences appeared between the mean sizes of the MXT cancers. In contrast, within the G2 group, which contained tumors equal to or larger than 120 mm2, CPA significantly slowed down tumor growth, while the administration of estradiol (E2) prior to CPA treatment antagonized the positive CPA-induced therapeutic effect. In conclusion, the non-invasive follow-up of the chemotherapeutic treatment of a clinically relevant mammary tumor model by 31P NMR spectroscopy backed up by statistical analyses revealed metabolic changes that appeared well before any modifications in histopathology or growth.

Animals

Correlation between liver scintigraphy and computed tomography in the detection of liver metastases.

Parallel scintigraphic and computed tomographic (CT-scan) examinations of the liver were carried out during the same observation period in 55 cancer patients in whom the liver status could be microscopically and macroscopically documented with regard to presence or absence of metastases. Scintigraphy was realized by means of 198Au or 99mTc-colloid using a rectilinear scanner or a gamma-camera; CT-scan images of the liver were obtained by a standard commercial instrument before and after injection of a contrast product. The liver was found to be normal in 38 out of the 55 observed patients and a metastatic involvement was seen in 17 cases. In 45 out of 55 cases, there was concordance between the results obtained by the two investigation methods and discordance in 10 cases. The sensitivity is 97% for the scintigraphy, 94% for the CT-scan and 100% for the common negative results. The specificity can be established as 64% for the scintigraphy, 65% for the CT-scan and 74% for common positive findings. It seems therefore that these two techniques present the same efficiency in the detection of liver metastases and that the results obtained are only partly complementary.

Female

Subcellular steroid distribution in the rat adrenal cortex.

The subcellular distribution of main steroids (pregnenolone, progesterone, corticosterone) and of cholesterol -- this last after correction according to exchanges occuring during differential centrifugation -- is presented in the rat adrenal cortex. The distribution patterns are not necessarily the same as established according to the localization of hydroxylating enzymes.

Adrenal Cortex

Cerebral blood flow under enflurane anesthesia.

Cerebral blood flow was measured, under controlled conditions of stable ventilation and PaCO2, in 11 patients suffering from cerebro-vascular lesions. Comparing the results under N2O-enflurane 1% anesthesia with those under N2O-fentanyl anesthesia shows an average 8.4% decrease of blood flow. In 5 cases, a third measurement was performed under N2O-enflurane 2% anesthesia. This caused an average 8.5% complementary decrease. Whereas most inhalational anesthetic agents produce an increase of cerebral blood flow, this is not observed with enflurane, the tendency rather being towards a decrease.

Adult

A rapid method for evaluation of regional cerebral blood flow after intra-arterial injection of 133Xe.

A technique based on the stochastic method is described for the computation of regional blood flow (RBF) after intra-arterial infection of 133Xe. Results are presented on scintigrams, defined by 600-800 channels in a 64 times 64 matrix. The content of each channel is equal to the computed RBF value. The standard deviation is also computed for each channel. The total computation cycle is achieved within 10 min. The method has been used to investigate the influence of anesthesia or drugs on regional blood flow. For this purpose, a differential printout program was written in which variations of RBF values between the two measurements are expressed in units of a fixed percentage; provision is made for calculation of RBF variations in units of differential standard deviations. Data are in good accordance with other clinical findings. This method is suitable for clinical use when blood flow values in gray and white substances are not requested.

Adolescent

Incorporation of [32P]-orthophosphate into total and individual plasma phospholipids in patients with polycythemia vera.

Incorporation of [32P]-orthophosphate into plasma phospholipids was investigated in 11 patients with polycythemia vera. The specific activity of phospholipid radioactive precursors (TCA-extract) was maximal 1 hour after the delivery of radioactive phosphorus and dropped to less than 20 per cent of maximal value after 24 hours. The peak of total phospholipid specific activity was observed 48 hours after the administration of [32P]-orthophosphate in 10 patients, and after 24 hours in one, and decreases regularly afterward. The half-life of the lipid-bound phosphorus in the plasma of investigated patients, determined during the decrease of their specific activity was 252+/-60 hours. Concentration of total plasma phospholipids and the pattern of individual phospholipid found in patients with polycythemia vera were similar to those reported for normal individuals. The rate of incorporation of the labeled phosphorus into phosphatidylethanolamine and phosphatidic acid was much more rapid than into lysophosphatidylcholine, sphingomyelin, or phosphatidylcholine.

Chromatography, Thin Layer

[Effects of radiotherapy on plasma T 1/2 59Fe in patients with lung cancer and lymphomas].

The variations of the plasma 59Fe T 1/2 were observed in 20 patients treated by high-energy irradiation. They were submitted to a focalized radiotherapy involving a non-negligible volume of erythropoietic marrow. Among them there were 10 cases of pulmonary cancer, 7 cases of lymphomas, and 3 cases of seminomas. When treatment was limited to an irradiation of the thorax, no significant change of the 59Fe T 1/2 was observed in cases of pulmonary cancer or lymphomas. In case of a supra and infradiaphragmatic irradiation (lymphomas), the 59Fe T 1/2 (initially subnormal) tended to reach normal values after radiotherapy and seems to be independent of the initial value (before irradiation) and of the delivered dose.

Cobalt Radioisotopes