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At least 325 records · Page 18Linked to original sources

Concomitant radio-chemotherapy based on platin compounds in patients with locally advanced non-small cell lung cancer (NSCLC): a meta-analysis of individual data from 1764 patients.

BACKGROUND: Despite several randomised trials comparing radiotherapy alone with concomitant radio-chemotherapy in patients with locally advanced non-small cell lung cancer (NSCLC), it is not clear whether the addition of chemotherapy improves survival. PATIENTS AND METHODS: This meta-analysis was based on individual patient data from published and unpublished randomised trials which compared radiotherapy alone with the same radiotherapy combined with concomitant cisplatin- or carboplatin-based chemotherapy. Trials with accrual completed after 2000 were excluded. Trials were sought in electronic databases, clinical trial registries and by additional manual searches. The primary endpoint was overall survival analysed using the log-rank test stratified by trials. RESULTS: There were twelve eligible trials that included a total of 1921 patients. The data from 3 trials were not available. Therefore, the analysis was based on 9 trials including 1764 patients. Median follow-up was 7.2 years. The hazard ratio of death among patients treated with radio-chemotherapy compared to radiotherapy alone was 0.89 (95% confidence interval, 0.81-0.98; P = 0.02) corresponding to an absolute benefit of chemotherapy of 4% at 2 years. There was some evidence of heterogeneity among trials and sensitivity analyses did not lead to consistent results. The combination of platin with etoposide seemed more effective than platin alone. CONCLUSIONS: Concomitant platin-based radio-chemotherapy may improve survival of patients with locally advanced NSCLC. However, the available data are insufficient to accurately define the size of such a potential treatment benefit and the optimal schedule of chemotherapy.

Aged↗

Clonal elimination of self reactive V beta 6+ T cells induced by H-2 products expressed on thymic radio-resistant components.

The role of thymic radio-resistant cells on clonal elimination of V beta 6+ T cells that are reactive to minor lymphocyte stimulatory (Mls)-1a plus I-E antigens has been investigated. Previous studies with allogeneic bone marrow chimeras revealed that radio-sensitive I-E+ cells derived from donor bone marrow in the thymus play a major role in the clonal elimination of V beta 6+ T cells. However, we could show that not only the thymic bone marrow derived components but also the radio-resistant ones (presumably thymic epithelial cells) might be involved in induction of clonal elimination of the self-reactive T cells. The proportion of V beta 6+ T cells present varied with the H-2 haplotype of the thymus and the cell types presenting Mls-1a products, which might be attributable to differences in the affinity of the H-2 products to T cell antigen receptors and differences in the amount of tolerogens expressed on the stromal cells.

Animals↗

Percutaneous radio-frequency ablation therapy using a clustered electrode for malignant liver tumors.

GOALS: To examine the safety and effectiveness of percutaneous radio-frequency ablation therapy (PRAT) for malignant liver tumors, using a needle with cluster radio-frequency (RF) electrodes. STUDY: The subjects were 13 patients with solitary malignant liver tumors: 10 had hepatocellular carcinoma and 3 had metastatic liver tumors. One session of PRAT with cluster RF electrodes was performed until roll-off occurred two times. Dynamic computed tomography (CT) and fine needle tumor biopsy under ultrasonographic guidance were conducted to assess the therapeutic efficacy. Aspartate aminotransferase, alanine aminotransferase, lactic dehydrogenase, and total bilirubin were evaluated before and 1, 3, and 7 days after PRAT. RESULTS: There were no serious complications. Aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels peaked 1 day after PRAT and decreased thereafter. No icterus occurred. Of the 13 tumors, 12 showed complete necrosis on dynamic CT; however, one of them showed histologically incomplete necrosis in the tumor biopsy. In both of the ineffective cases, the tumors were located near relatively large vessels. There was no recurrence in the liver in all cases of PRAT that were effective (observation periods: 6--14 months; mean, 10 months). CONCLUSIONS: Percutaneous radio-frequency ablation therapy using a clustered electrode is a safe and effective treatment of malignant liver tumors, if the tumor is not located near the large vessels.

Aged↗

Controlled comparison of radio wave regional hyperthermia and peritoneal lavage rewarming after immersion hypothermia.

Anesthetized random source dogs were cooled by ice-water immersion to a stable core temperature of 25 degrees C and subsequently rewarmed with normal saline peritoneal lavage (43 degrees C, 175 ml/kg/hr) or radio frequency electromagnetic-induced regional hyperthermia (4-6 watts/kg). The mean time required for core rewarming to 30 degrees C was 183 +/- 79 minutes for lavage and 58 +/- 13 minutes for radio wave therapy (p less than 0.01). There was no evidence of tissue damage with either modality. These data suggest radio wave regional hyperthermia is superior to peritoneal lavage for core rewarming of rapidly induced immersion hypothermia.

Animals↗

Treatment of simple snoring using radio waves for ablation of uvula and soft palate: a day-case surgery procedure.

OBJECTIVE: Uvulopalatoplasty, performed with high-frequency radio waves, was evaluated as a treatment for social snoring. METHODS: Forty male social snorers were included in this prospective, nonrandomized study. Patients' subjective complaints before, during, and 3 months after radio-assisted uvulopalatoplasty were recorded on a visual analogue scale. RESULTS: Complications were negligible. Snoring sounds and daytime tiredness reduced significantly. Considering effect and suffering during and after surgery, a high number of patients (93%) were willing to undergo the procedure again if necessary. CONCLUSIONS: The results of radio-assisted uvulopalatoplasty (RAUP) seem to be similar to other surgical methods used to reduce snoring. The relative small investments needed and its simplicity makes RAUP a good alternative to known treatment strategies.

Ambulatory Surgical Procedures↗

Minimally invasive parathyroidectomy: the role of radio-guided surgery.

OBJECTIVES: Objectives were to review our current experience with radio-guided parathyroid surgery and to compare various techniques of minimally invasive parathyroidectomy. STUDY DESIGN: 1) To review our recent experience of radio-guided gamma probe localization during surgery for primary hyperparathyroidism and 2) to compare the intraoperative findings with the preoperative sestamibi scan. METHODS: Analysis was made of the 10 most recent surgical procedures for primary hyperparathyroidism at a single institution to compare the operative localization with preoperative sestamibi scan and to determine the radioactivity in the tissue removed during surgery, such as parathyroid adenoma, normal parathyroid gland, thyroid tissue, or lymph nodes. RESULTS: The sestamibi scan was able to localize the enlarged parathyroid gland in eight patients. Although gamma probe was helpful in localizing the parathyroid gland, the identification of an enlarged parathyroid gland was directly based on the preoperative findings of sestamibi scan. In the remaining two patients, the intraoperative gamma probe was not helpful. CONCLUSIONS: The major advantage of gamma probe in the series was to evaluate the radioactivity in the tissue that was removed and to determine whether it was an enlarged parathyroid gland, lymph node, thyroid tissue, or fatty tissue. The radio-guided surgery did not add substantially to the surgical procedure in patients in whom the sestamibi scan had localized the enlarged parathyroid gland preoperatively.

Adult↗

Long-term followup of patients with renal cell carcinoma treated with radio frequency ablation with curative intent.

PURPOSE: We defined the role of radio frequency ablation in the treatment of renal cell carcinoma. MATERIALS AND METHODS: A total of 16 patients with biopsy proven renal cell carcinoma were treated with radio frequency ablation in an outpatient setting and followed for a minimum of 4 years. RESULTS: Of the 16 patients 5 died before 4 years of followup of unrelated causes. All except 1 tumor was successfully treated. All patients with exophytic tumors were successfully treated. CONCLUSIONS: Radio frequency ablation of exophytic renal cell carcinomas less than 5 cm in diameter is effective in eradicating the tumor and comparable to surgical extirpation at 4 years.

Adult↗

Radio frequency ablation (RFA)-assisted pericystectomy for hepatic echinococcosis: an alternative technique.

The aim of this study is to describe an alternative technique, using radio frequency energy to perform pericystectomy for hepatic echinococcosis. We present 3 patients with hepatic echinococcosis who were treated with radio frequency ablation (RFA)-assisted pericystectomy. A Radionics Cooltip Radio Frequency System (Tyco, Greece, Radionics) with a single shaft 15 cm long needle electrode and a 2 cm exposure tip, was used. The needle electrode was inserted in consecutive sites into the "healthy" hepatic parenchyma close to the cyst wall, so that a tissue zone around the cystic cavity was gradually ablated. The complete ablation of a site was followed by sharp division of the parenchyma. The operation completed successfully in all patients. Minor bleeding and/or bile leakage were successfully controlled with RFA coagulation. No other hemostatic method was used. The postoperative course was uneventful. No evidence of recurrent disease, or any other cause of morbidity, has been demonstrated at follow up (2 y). RFA-assisted pericystectomy for hepatic hydatid disease in experienced hands, might be useful to perform a "sterile" resection, eradicating single or multiple cysts and preventing local recurrence, with minimal morbidity.

Adult↗

Radio-frequency measurements of coherent transition and cherenkov radiation: implications for high-energy neutrino detection

We report on measurements of (11-18)-cm wavelength radio emission from interactions of 15.2 MeV pulsed electron bunches at the Argonne Wakefield Accelerator. The electrons were observed both in a configuration where they produced primarily transition radiation from an aluminum foil, and in a configuration designed for the electrons to produce Cherenkov radiation in a silica sand target. Our aim was to emulate the large electron excess expected to develop during an electromagnetic cascade initiated by an ultrahigh-energy particle. Such charge asymmetries are predicted to produce strong coherent radio pulses, which are the basis for several experiments to detect high-energy neutrinos from the showers they induce in Antarctic ice and in the lunar regolith. We detected coherent emission which we attribute both to transition and possibly Cherenkov radiation at different levels depending on the experimental conditions. We discuss implications for experiments relying on radio emission for detection of electromagnetic cascades produced by ultrahigh-energy neutrinos.

Journal Article↗

Cross correlation of the cosmic microwave background with radio sources: constraints on an accelerating universe.

We present a new limit on the cosmological constant based on the absence of correlations between the cosmic microwave background (CMB) and the distribution of distant radio sources. In cosmological constant, cold dark matter ( LambdaCDM) models, such correlations should have been produced via the integrated Sachs-Wolfe effect, assuming that radio sources trace the local ( z approximately 1) matter density. We find no evidence of correlations and obtain a 95% C.L. upper limit on the cosmological constant of Omega(Lambda)< or =0.74. If 0.6<Omega(Lambda)<0.7 as suggested by recent CMB anisotropy and supernovae observations, then the integrated Sachs-Wolfe effect should be detectable with upcoming CMB maps and radio surveys.

Journal Article↗

The use of lead methacrylate 2-ethylhexanoate to create a radio-opaque resin suitable for microvascular corrosion casting.

A radio-opaque methacrylate-based resin suitable for microvascular corrosion casting can be prepared by substituting lead methacrylate 2-ethylhexanoate for a proportion of the methyl methacrylate monomer normally used. Best results are achieved when conventional methacrylate resin is injected first to fill the vascular tree, and this is chased with the radio-opaque resin. The pattern of arterial and arteriolar distribution can then subsequently be followed by means of a radiographic survey of the cast, and this is of value prior to sampling from vascular systems which show functional subdivisions that cannot be correlated with any surface features. The radio-opacity of the resin and the quantity injected can be varied easily to suit individual requirements.

Acrylates↗

Assessment of visceral sensitivity using radio telemetry in a rat model of maternal separation.

Stress plays an important role in the development of visceral hypersensitivity, a key mechanism underlying the pathophysiology of the irritable bowel syndrome. Visceral sensitivity in rats is generally assessed under restrain conditions. To avoid this potential stress factor, we developed a model using implanted radio telemetry for remote measurement of the visceromotor response (VMR) to colorectal distention (CRD). Ten days after implantation of a radio telemetry transmitter and EMG electrodes, visceral sensitivity was evaluated by applying a standardized distension protocol (1, 1.5 and 2 mL) on three different days. In a second series, visceral sensitivity was assessed in maternally separated rats before, directly after and at 6 and 24 h after water avoidance (WA) stress. CRD resulted in a reproducible VMR response on the three different study days. In separated but not in non-handled rats, WA significantly increased visceral sensitivity at 6 h (P=0.006) and 24 h (P=0.004) after WA. Our results show that radio telemetry is a reliable and well tolerated new tool for evaluating visceral sensitivity in rats. These data further confirm that maternal separation is a good model for evaluating the mechanisms underlying visceral hypersensitivity.

Abdominal Muscles↗

24 hour/3 hour radio-uptake technique for differentiating degenerative and malignant bony lesions in bone scanning.

Differentiating bony metastases from degenerative lesions is of great importance to the oncologist. Routine bone scanning using technetium-99m methylene diphosphonate is the investigation of choice for detecting bony lesions, but its specificity is low. Using the difference in radio-uptake behaviour of metastatic and degenerative lesions as the criterion, a 24/3 h radio-uptake, lesion to non-lesion ratio was used to separate out the two types of lesions. Radio-uptake ratio (RUR) distribution curves of malignant and degenerative lesions were found to be significantly different (P < 0.001). Taking 1.12 as the critical point, RUR of malignant lesions was found to be more than the critical point, and that of degenerative lesions was found to be less than the critical point. Sensitivity, specificity and accuracy were found to be 68%, 80% and 74%, respectively.

Bone Diseases↗

The influence of coumarin on tissue levels of radio-labelled plasma protein and povidone (polyvinylpyrrolidine) in normal and thermally injured rats.

1. The administration of coumarin resulted in a two-fold increase in the entry of 51Cr-labelled rat plasma protein into otherwise normal tissues. 2. Prior treatment of rats with coumarin allowed about 50% more radio-labelled protein to enter the tissues immediately after thermal injury than occurred with thermal injury in untreated rats. 3. In coumarin-treated rats, 30 min or more after thermal injury, tissue levels of 125I-labelled povidone (polyvinylpyrrolidine) were significantly elevated or showed no change compared with tissue levels in rats which received only thermal injury. 4. Conversely, tissue levels or radio-labelled protein in coumarin-treated rats, 30 min or more after thermal injury were significantly reduced to between 20 and 30% of those in untreated, thermally injured rats. 5. These results were attributed to enhanced proteolysis of the radio-labelled protein caused by coumarin. Other results have shown that normal protein is similarly affected. 6. The products of proteolysis may then rapidly leave the tissues, freeing the osmotically-held fluids and reducing the oedema.

Animals↗

Radio-frequency ablation of renal cell carcinoma in patients who were at significant risk.

OBJECTIVE: Although radio-frequency ablation (RFA) has been recently applied as a minimally invasive treatment option for renal cell carcinoma (RCC), indication of this modality remains a critical issue due to the lack of complete tumor destruction as well as the uncertainty of its long-term efficacy. We report the efficacy of RFA for nine carefully selected patients with RCC who had significant reason to avoid invasive surgical treatment under general anesthesia. METHODS: Radio-frequency ablation was performed under epidural or local anesthesia by ultrasound or computed tomography (CT) guidance in nine patients with biopsy proven RCC (mean diameter, 38 mm; range, 20-53 mm), who were at significant operative or anesthetic risk for invasive surgery. Follow-up enhanced CT scans or magnetic resonance images were evaluated every 3-6 months and an evaluation of metastasis was performed every 6 months. RESULTS: At a mean follow-up of 17 months, seven (78%) of the nine patients with renal tumor showed no tumor enhancement. The renal function of all patients was well preserved. All patients were able to continue undergoing their respective treatments for active diseases in other organs in parallel to the RFA treatment. No distant metastasis, urine leakage were reported and one case of temporary hematuria and one case of peri-renal hemorrhage not requiring blood transfusion were encountered. Intra-operative ultrasonography was useful in the real-time monitoring of the minimally excessive extension of ablation into the normal parenchyma. CONCLUSION: Radio-frequency ablation appears to be an effective and safe minimally invasive therapeutic option for selected patients with RCC who have reason to avoid invasive surgery under general anesthesia.

Aged↗

Hide and seek: pre-operative ultrasonic localization of non radio-opaque foreign bodies.

Ultrasound has long been used as a diagnostic and therapeutic tool in surgery. We have extended its use to hand surgery, where is has several applications. Non radio-opaque foreign body extraction is invariably a frustrating exercise of 'hide and seek'. Accurate pre-operative localization with ultrasound illustrating size, shape, depth, soft tissue and bony relationships can ensure rapid and complete removal. Several cases are presented to demonstrate the use of ultrasound for the detection of non radio-opaque foreign bodies. The technique used will be described. We feel pre-operative localization by ultrasound is a useful technique to assist with the removal of non radio-opaque foreign bodies.

Adolescent↗

Randomised controlled trial of bipolar radio-frequency endometrial ablation and balloon endometrial ablation.

OBJECTIVE: To compare the effectiveness of two second-generation ablation techniques, bipolar radio-frequency impedance-controlled endometrial ablation (NovaSure) and balloon ablation (ThermaChoice), in the treatment of menorrhagia. DESIGN: Double-blind, randomised, controlled trial. SETTING: A large teaching hospital with 500 beds in The Netherlands. POPULATION: Women suffering from menorrhagia referred by their general practitioner. METHODS: Women suffering from menorrhagia, without intracavitary abnormalities, were randomly allocated to bipolar radio-frequency ablation (bipolar group) and balloon ablation (balloon group) in a 2:1 ratio. At follow up, both women and observers were unaware of the type of treatment that had been performed. MAIN OUTCOME MEASURES: The main outcome measure was amenorrhea at 3, 6 and 12 months after randomisation. RESULTS: One hundred and twenty-six women were included in the study, of which 83 were allocated to the bipolar group, and 43 to the balloon group. No complications occurred in either of the treatment groups. At the one-year follow up stage, amenorrhea rates were 43% (34/83) in the bipolar group and 8% (3/43) in the balloon group (treatment effect in time P < 0.001). At this stage, 90% of the patients in the bipolar group were satisfied with the result of the treatment against 79% in the balloon group (treatment effect in time P= 0.003). CONCLUSION: The bipolar radio-frequency impedance-controlled endometrial ablation system is more effective than balloon ablation in the treatment of menorrhagia.

Adult↗

Discovery of a compact radio component in the center of supernova 1986J.

Very-long-baseline interferometry observations have revealed a bright, compact radio component near the center of the expanding shell of supernova 1986J. The component, not present in earlier images, has an inverted radio spectrum different from that of the shell. Such an inversion has not been seen in the spectrum of any other supernova. The new component is likely radio emission associated either with accretion onto a black hole or with the nebula formed around an energetic young neutron star in the center of SN 1986J, which would directly link either a black hole or a neutron star to a modern supernova.

Journal Article↗