Dexamethasone-Induced Enhancement of Resistance to Ionizing Radiation and Chemotherapeutic Agents in Human Tumor Cells

Background: Dexamethasone-induced changes in radioresistance have previously been observed by several authors. Here, we examined effects of dexamethasone on resistance to ionizing radiation in 10 additional human cell lines and strains, and on resistance to carboplatin and paclitaxel in 13 fresh tumor samples. Material and Methods: Eight human carcinoma cell lines, a glioblastoma cell line and a strain of normal human diploid fibroblasts were arbitrarily chosen for these in-vitro studies. Effects on radiosensitivity were assessed using a conventional colony formation assay. Effects on resistance to the drugs were investigated prospectively (ATP cell viability assay) using 13 fresh tumor samples from consecutive patients operated for ovarian cancer within the context of a Swiss nation-wide randomized prospective clinical trial (SAKK 45/94) Results: Dexamethasone promoted proliferation of 1 of the cell lines without affecting radiosensitivity, while it completely inhibited proliferation of another cell line (effects on radiosensitivity could thus not be examined). Furthermore, dexamethasone induced enhanced radioresistance in 1 of the 8 carcinoma cell lines examined. In the glioblastoma cell line, there was no effect on growth or radioresistance in 1 of the 8 carcinoma cell lines examined. In the glioblastoma cell line, there was no effect on growth or radioresistance, nor in the fibroblasts. Treatment with dexamethasone enhanced resistance of the malignant cells to carboplatin in 4 of the 13 fresh tumor samples examined, while no enhancement in resistance to paclitaxel was observed. Conclusions: In agreement with previous reports, we found that dexamethasone may induce radioresistance in human carcinoma cells. Including the published data from the literature, dexamethasone induced enhancement in radioresistance in 4 of 12 carcinoma cell lines (33%), but not in 3 glioblastoma cell lines, nor in 3 fibroblast strains. Dexamethasone also induced enhanced resistance to carboplatin with a similar probability in fresh samples of ovarian cancer evaluated prospectively (in 4 of 13 samples; 31%). We worry that induction of resistance by corticosteroids given to patients undergoing either radiotherapy or chemotherapy with agents causing DNA damage might be associated with a reduced clinical responsiveness in a significant fraction of patients with a carcinoma. Hintergrund: In der Literatur gibt es verschiedene Berichte über eine dexamethasoninduzierte Erhöhung der Strahlenresistenz. Wir untersuchten deshalb weitere menschliche Tumorzellinien und Fibroblasten auf induzierbare Veränderungen der Wachstumsfähigkeit und der Strahlenempfindlichkeit. Außerdem prüften wir die Wirkung von Dexamethason auf die Sensibilität von Ovarialkarzinomproben gegenüber Carboplatin und Paclitaxel. Material und Methode: Wir untersuchten acht Karzinomzellinien, eine Glioblastomzellinie sowie Hautfibroblasten in Kultur. Die Wirkung auf die Wachstumsfähigkeit der Zellen und auf die Strahlenwirkung wurde unter Verwendung des üblichen Koloniebildungstests bestimmt. Die Wirkung von Dexamethason auf die Effekte der Chemotherapeutika Carboplatin und Paclitaxel wurde an Proben von 13 konsekutiven Ovarialkarzinomen im Rahmen einer klinischen Studie (SAKK 45/94) prospektiv untersucht (ATP cell viability assay). Ergebnisse: Dexamethason stimulierte das Wachstum einer Karzinomzellinie, ohne die Strahlenresistenz zu beeinflussen. Außerdem wurde das Wachstum einer anderen Zellinie vollständig gehemmt, so daß die Wirkung auf die Strahlenempfindlichkeit nicht untersucht werden konnte. Dexamethason bewirkte in einer der übrigen Karzinomzellinien eine erhöhte Resistenz gegenüber Bestrahlung. Wachstumsfähigkeit und Strahlenempfindlichkeit von Glioblastomzellen und Fibroblasten wurden nicht beeinflußt. Außerdem induzierte Dexamethason eine erhöhte Resistenz gegenüber Carboplatin in vier der 13 Ovarialkarzinomproben. Eine erhöhte Resistenz gegenüber Paclitaxel wurde hingegen nicht beobachtet. Schlußfolgerungen: Diese Ergebnisse bestätigen frühere Berichte über dexamethasoninduzierte Resistenz gegenüber Bestrahlung. Einschließlich der in der Literatur publizierten Daten findet sich eine dexamethasoninduzierte Erhöhung der Resistenz in vier von zwölf evaluierbaren Karzinomzellinien (33%), nicht jedoch in den drei Glioblastomzellinien oder in Fibroblasten. Dexamethason erzeugte ähnlich häfuig, nämlich in vier von 13 Proben (31%), eine erhöhte Resistenz gegenüber Carboplatin. Dexamethasongabe könnte sich deshalb negativ auswirken.     

乳腺浸润性导管癌超声影像特征分析

 目的 分析超声各特征性影像表现在乳腺浸润性导管癌中的诊断价值。方法 选取解放军总医院第六医学中心 2018-01至2019-12两年内收治的 135例乳腺浸润性导管癌患者纳入本研究,分析乳腺浸润性导管癌的超声影像特征、体检自检发现率以及淋巴结转移与病变大小、位置的相关性。结果 (1)单因素分析显示:形态不规则(91.11%)、边界不清楚(64.44％)、血流信号(44.44％)、微钙化(37.78%)、纵横比＞1(17.78％)、后方回声衰减(15.56％)超声诊断指标,与浸润性导管癌的诊断具有相关性;(2)与其他三个象限相比较,内上象限浸润性导管癌更容易被患者自检发现,占自检发现病例的34.93%;(3)内上象限及外上象限的浸润性导管癌更容易发生淋巴结转移(转移率为:内上:25.53%,内下:0.00%,外上:64.70%,外下:11.76%);(4)对＜3 cm的浸润性导管癌,其大小与腋窝淋巴结的转移没有相关性。结论 超声表现以形态不规则在乳腺浸润性导管癌中的发生率最高,且在早期病变中即表现出来;乳腺病变的自检检出率、乳腺癌淋巴转移率均与乳腺病变的大小和位置密切相关。     

MR coronary angiography in pigs with intraarterial injections of a hyperpolarized 13C substance.

A new diagnostic application of a water-soluble contrast medium (CM) based on the hyperpolarization of a 13C substance is introduced. The degree of polarization achieved is >30%, which is about a factor of 10(5) higher than the thermal equilibrium polarization level at 1.5 T. Imaging of hyperpolarized (HP) CM during a cardiac interventional MRI procedure was studied. Catheters were positioned in the left and right coronary arteries of pigs. A coil tuned to 13C was used for nonproton imaging. The HP-13C CM ( approximately 5 ml, 0.5 M, approximately 30% polarization) was injected during projection imaging using a fully balanced steady-state free precession (SSFP) pulse sequence with and without cardiac gating. The contrast agent-filled catheter was clearly visible during the procedure. The coronary arteries were well depicted and the signal-to-noise ratios (SNRs) were in the range of 10-40. The use of HP-13C CM may provide a new diagnostic procedure for interventional MRI.     

No overrepresentation of congenital adrenal hyperplasia in patients with adrenocortical tumours

OBJECTIVE: The development and progression of sporadic adrenocortical tumours are poorly understood. In autopsy studies adrenocortical tumours are found in between 2 and 9% of the general population. In congenital adrenal hyperplasia (CAH), decreased production of cortisol leads to increased secretion of ACTH from the pituitary, resulting in hyperplasia of the adrenals. More than 95% of all cases of CAH are due to steroid 21-hydroxylase deficiency, resulting from mutations in the CYP21 gene. In subjects homozygous and heterozygous for CYP21 mutations, adrenocortical tumours have been found in a high frequency compared to the general population, suggesting that chronic ACTH stimulation may play a role in the development of this tumour form. In order to test whether mild undiagnosed CAH is a common predisposing factor, we screened 27 patients with sporadic adrenocortical tumours for CYP21 mutations. DESIGN: A retrospective study. PATIENTS: We screened 27 patients with sporadic adrenocortical tumours, representing both benign and malignant as well as hormonally active and silent lesions. MEASUREMENTS: Mutation analyses of the CYP21 gene was performed by allele-specific PCR on high molecular weight DNA. The method used detects the nine CYP21 mutations that are responsible for 95% of all disease-causing alleles in CAH. RESULTS: No mutations were detected in any of the 23 DNA samples that were prepared from leucocytes. In 4 cases where no leucocyte DNA was available, tumour tissue was analysed. In one of these tumours, two CYP21 mutations, V281 L and L307insT, were found in heterozygous form. CONCLUSION: Our data indicate that mild undiagnosed congenital adrenal hyperplasia is not a common underlying factor predisposing to adrenocortical tumours, at least not in the Swedish population.     

Sclerosing injections to treat midportion Achilles tendinosis: a randomised controlled study evaluating two different concentrations of Polidocanol

Two to three ultrasound (US) and colour Doppler (CD)-guided injections of the sclerosing substance Polidocanol (5 mg/ml) have been demonstrated to give good clinical results in patients with chronic midportion Achilles tendinopathy. This study aimed to investigate if a higher concentration of Polidocanol (10 mg/ml) would lead to a less number of treatments, and lower volumes, needed for good clinical results. Fifty-two consecutive Achilles tendons (48 patients, mean age 49.6 years) with chronic painful midportion Achilles tendinopathy, were randomised to treatment with Polidocanol 5 mg/ml (group A) or 10 mg/ml (group B). The patients and treating physician were blinded to the concentration of Polidocanol injected. All patients had structural tendon changes and neovascularisation in the Achilles midportion. Treatment was US + CD-guided injections targeting the region with neovascularisation (outside ventral tendon). A maximum of three treatments (6-8 weeks in between) were given before evaluation. Patients not satisfied after three treatments were given additional treatment with Polidocanol 10 mg/ml, up to five treatments. For evaluation, the patients recorded the severity of Achilles tendon pain during activity on a visual analogue scale (VAS), before and after treatment. Patient satisfaction with treatment was also assessed. At follow-up (mean 14 months) after three treatments, 18/26 patients in group A and 19/26 patients in group B were satisfied with the treatment and had a significantly reduced level of tendon pain (P < 0.05). After completion of the study, additional treatments with Polidocanol 10 mg/ml in the not satisfied patients resulted in 26/26 satisfied patients in both groups A and B. In summary, we found no significant differences in the number of satisfied patients, number of injections or volumes given, between patients treated with 5 or 10 mg/ml Polidocanol.