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Biomedical subjects

E Rummeny

Publications and source records attributed to E Rummeny.

47 records · Page 3Linked to original sources
PubMed1987

Effects of oxygen on the metabolism of murine tumors using in vivo phosphorus-31 NMR.

The effect of 100% inspired oxygen on in vivo tumor metabolism was examined using phosphorus-31 (31P) NMR spectroscopy. Isotransplants of two murine tumor histologies, designated MCaIV (C3H mammary adenocarcinoma) and FSaII (C3H fibrosarcoma), were used in syngeneic mice. Tumor volumes ranged from 30 to 1,800 mm3. Both tumor histologies are known to have a high hypoxic cell fraction when tumor volumes exceed 250 mm3. 31P nuclear magnetic resonance (NMR) spectra were obtained at 145.587 MHz, and the signal was detected using a 1.4 cm diameter, single loop coil designed to localize the signal from only the tumor. Spectral parameters for optimal signal-to-noise ratio (SNR) included a 60 degrees pulse and a 2-second recycle delay. Tumors were implanted in the hindfoot dorsum to assure that all detected mobile phosphates were of tumor origin. Phosphocreatine/inorganic phosphate (PCr/Pi) ratios of large tumors (greater than 250 mm3) were reduced compared with small tumors (less than 250 mm3) of the same histology. The increased PCr/Pi response to 100% inspired oxygen was greater for large tumors and for tumors with lower baseline PCr/Pi ratios. When host animals were given 10% oxygen for respiration, there was an increase in Pi and a decrease in both PCr and ATP. The response to 10% oxygen was observed in both large and small tumors of both tumor histologies studied. Resting skeletal muscle exhibited no alteration in the NMR spectrum during either 100 or 10% oxygen breathing. We conclude that the fractional increase in PCr/Pi ratio that occurs after 100% oxygen breathing is a sensitive, noninvasive method of detecting tumor hypoxia.

Animals↗
PubMed1987

MR imaging of splenic metastases: ferrite-enhanced detection in rats.

Detection of intrasplenic neoplasms using sonography, CT, and scintigraphy is limited by poor inherent tumor-spleen contrast relative to image noise. Despite the wide range of contrast parameters available for MR imaging, similar limitations have been found with this technique. Magnetopharmaceuticals have the ability to enhance tumor-spleen contrast and improve lesion detectability. In this study, a rodent model of cancer metastasized to the spleen was used to evaluate the potential of superparamagnetic ferrite particles as a tissue-specific reticuloendothelial contrast agent. Other studies have shown ferrite to have little or no toxicity. Without contrast material, metastatic adenocarcinoma of the spleen could not be distinguished from normal splenic parenchyma on in vivo MR images. At a dose of 50 mumol Fe/kg, the T2 relaxation time of spleen decreased by 77%, while tumor T2 was essentially unchanged (p less than .005). Intrasplenic tumors 4-6 mm in size became readily detectable on in vivo MR images after the administration of ferrite particles. Lesion conspicuity, quantitated by the tumor-spleen contrast-to-noise ratio, showed a 43-fold increase. Ferrite particles show great promise as a contrast agent to enhance the detection of focal splenic lesions.

Adenocarcinoma↗
PubMed1986

[Single photon emission computed tomography of patients with benign and malignant spinal diseases].

SPECT has been used in a comparative study with planar bone scintigraphy in 54 patients. Spatial resolution of the method is sufficient to localise the vertebral bodies, the spinous processes, the intervertebral, costotransverse and costovertebral joints. In all patients it was possible to relate the areas of increased uptake to specific anatomical sites of the spine known to be affected in the different conditions. A detailed localisation is rarely possible using planar scintigraphy alone, due to the complex osseous anatomy of the spine. In some patients lesions could be seen only with SPECT. SPECT is an invaluable supplement to planar scintigraphy of the spine.

Adult↗
PubMed1986

Pharmacokinetics of bisoprolol and influence on serum thyroid hormones in hyperthyroid patients.

Nine hyperthyroid patients (FT4 greater than or equal to 20 ng/L; FT3 greater than or equal to 6 ng/L) were given 1 X 10 mg bisoprolol/day p.o. for a period of 7 days. Pharmacokinetic data were derived from measurements of plasma bisoprolol concentrations after the first dose and at steady state after 7 days treatment. The thyroid hormones FT4, FT3, and rT3 were determined in the serum before and after bisoprolol treatment. In addition, subjective and objective parameters of thyroid function were recorded during the course of the therapy. The maximum bisoprolol concentrations measured after the first dose and after 7 days were 54.3 +/- 2.1 and 70.3 +/- 3.8 ng/ml, respectively, the minimum concentrations being 9.6 +/- 1.0 ng/ml and 11.9 +/- 1.7 ng/ml, respectively. This yields an accumulation factor of 1.2. At steady state, the plasma elimination half-life of bisoprolol was 9.8 +/- 0.9 h. No significant changes in serum thyroid hormones were observed during bisoprolol treatment. There was, however, an improvement in the subjective and objective clinical symptoms of hyperthyroidism. In comparison with the findings in healthy volunteers, the pharmacokinetics of bisoprolol remained unaltered in mild to moderate hyperthyroid patients. After oral application of bisoprolol, only small variations in the plasma concentration were observed inter- and also intraindividually in the course of treatment. This finding reflects the high absolute bioavailability of bisoprolol.

Adrenergic beta-Antagonists↗
PubMed1984

[Acquired infundibular pulmonary stenosis. Possible late complication following radiotherapy of Hodgkin disease].

A case of infundibular pulmonary stenosis occurring years after a mediastinal radiation for Hodgkin's disease is reported. As far as the literature is known to us, a similar case has not yet been described. It is most likely that the development of the stenosis is due to the radiation therapy, since a murmur was not heard before radiation and a mild stenosis was proved several years after radiation. Now, a high gradient with the typical signs of an infundibular pulmonary stenosis was present. Unfortunately the patient refused the operation. Further possibilities for acquired pulmonary stenosis and cardial complications after mediastinal radiation for Hodgkin's disease will be discussed.

Adult↗
PubMedDate not supplied

Preliminary clinical experience with laser-induced interstitial thermotherapy in patients with hepatocellular carcinoma.

The purpose of this preliminary study was to evaluate whether laser-induced interstitial thermotherapy (LITT) may be used for palliative treatment of localized hepatocellular carcinomas (HCC). We applied LITT to two patients suffering from unresectable localized hepatocellular carcinomas of different sizes (2.5 and 4 cm). LITT was performed with an Nd:YAG laser (1,064 nm) at 5 W laser power (15-20 minutes). Thermometry during LITT was performed by MRI using a temperature-sensitive T1-weighted fast low-angle shot (FLASH) sequence. Follow-up for local tumor control was performed by MRI and ultrasound. LITT was well tolerated and no adverse events occurred during or after LITT; no secondary liver lesions were seen in the follow-up (11 or 12 months, respectively). Only minimal tumor growth was observed in the larger HCC (from 4 to 5 cm), whereas the smaller HCC remained unchanged in size during 11 months of follow-up. We conclude that LITT might be an effective minimally invasive palliative treatment option for patients with small unresectable HCC.

Aged↗
PubMedDate not supplied

[The use of massive allograft in reconstruction following resection of bone tumors of the extremities].

Reported are indications, techniques and clinical outcome of 45 patients with resection of a primary malignant or aggressive benign tumor of the extremities, reconstructed with an allograft. The goal of this procedure is to achieve a wide resection of the tumor and to reconstruct the defect saving the limb. Bridging the osseous defect, we used an osteochondral allograft (14), intercalary allograft (16), allograft arthrodesis (14) and composite reconstruction (1). There were 3 deep infections, 3 superficial infections, 2 pseudarthrosis and 1 rejection found as complications. After local revision of the infections by allograft explantation and temporary implantation of antibiotic-loaded chains, another allograft could be implanted with success. Using different, individual adapted operative methods and allografts, a broad spectrum of bone defects after resection of bone tumors and, if necessary revisions, can be treated.

Adolescent↗