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At least 937 records · Page 52Linked to original sources
PubMed2000

High energy transurethral microwave thermotherapy for the treatment of patients in urinary retention.

PURPOSE: We evaluated the efficacy of high energy transurethral microwave thermotherapy for treating urinary retention due to benign prostatic hyperplasia. MATERIALS AND METHODS: Between October 1993 and March 1999, 41 patients with urinary retention were treated with high energy transurethral microwave thermotherapy. Initial evaluation consisted of a history, clinical examination, urethrocystoscopy, transrectal prostate ultrasonography and urodynamic investigation with a pressure flow study. Followup visits at 12, 26 and 52 weeks included International Prostate Symptom Score (I-PSS), uroflowmetry and post-void residual urine volume determination. At 26 weeks the urodynamic study was repeated. Kaplan-Meier plots were constructed to evaluate the risk of re-treatment adjusted for patients lost to followup. RESULTS: At baseline median patient age was 74 years and median prostate size was 67 ml. Median 133 kJ. were administered. Nine patients underwent re-treatment and 11 were lost to followup. The re-treatment rate after 1 year was 25% (95% confidence interval 11 to 40). In good responders at 12, 26 and 52 weeks median maximal urine free flow was 15, 11 and 15 ml. per second, post-void residual urine volume was 61, 8 and 35 ml., and I-PSS was 7, 5 and 2, respectively. Quality of life (I-PSS question 8) was 1 at all visits. CONCLUSIONS: In patients with severe co-morbidity transurethral microwave thermotherapy is often the only alternative to an indwelling catheter with obvious quality of life advantages. High energy transurethral microwave thermotherapy appears to be effective in these patients.

Aged↗
PubMed2000

Inhibitory action of microwave radiation on gamma-glutamyl transpeptidase activity in liver of rats treated with hydrocortisone.

The influence of microwave irradiation on the activity of gamma-glutamyl transpeptidase (GGT) induced by hydrocortisone (HC) in the liver of rats was investigated. Animals were subjected to microwave irradiation (frequency 53.57 GHz, power density 10 mW/cm2 and 1 mW/cm2) during and after hydrocortisone (HC) treatment (20 mg/kg for 60 days). The results indicate that microwave radiation may block an inducible effect of HC on GGT activity in the liver of rats. This effect depends on the power density of millimetre microwaves.

Animals↗
PubMed2000

[Microwave heating modulation of skin fibrosis in chronic extremity lymphedema].

OBJECTIVE: To observe the effects of microwave heating on skin fibrosis in chronic extremity lymphedema. METHODS: Skin specimens from 8 cases of chronic limb lymphedema were tested by in situ hybridization (ISH) combined with avidin-biotin peroxidase (ABC) immunohistochemistry for detection of TGF-beta, procollagen I, procollagen III mRNAs and corresponding peptides expressions. RESULTS: It was discovered that expressions of TGF-beta 1 peptide were located at the spinous and granular layer of the epidermal cells with a great amount of dermal collagen I, III formation in accordance with high expressions of TGF-beta, procollagen I, procollagen III mRNAs in the dermal and subcutaneous tissue fibroblasts. After microwave heating treatment, the epidermal expression of TGF-beta 1 and relative TGF-beta, procollagen I, procollagen III mRNAs expressions in dermal fibroblasts were greatly reduced. The smaller calibre of collagen fibers after microwave heating was also observed. CONCLUSIONS: It is indicated that fibrosis in lymphedema is resulted from overexpressions of relevant genes like TGF-beta and subsequent extracellular matrixes (ECM) syntheses and deposition. Microwave heating can reduce fibroblast expressions of TGF-beta, procollagen I, procollagen III mRNAs as well as TGF-beta peptide synthesis, inhibiting ECM syntheses and deposition and finally reverse the skin fibrosis process.

Adolescent↗
PubMed2001

Long-term followup of randomized transurethral microwave thermotherapy versus transurethral prostatic resection study.

PURPOSE: We evaluate the durable effect of high-energy transurethral microwave thermotherapy and transurethral prostatic resection for treatment of patients with lower urinary tract symptoms suggestive of bladder outflow obstruction. MATERIALS AND METHODS: Between January 1996 and March 1997, 155 patients with lower urinary tract symptoms suggestive of bladder outflow obstruction were randomized to receive transurethral microwave thermotherapy (Prostatron*; device and commercial software) (82) or undergo transurethral prostatic resection (73). Initial patient evaluation was performed according to international standards. Patients were followed annually with the International Prostate Symptom Score (I-PSS) and uroflowmetry (maximum flow rate). The Kaplan-Meier survival analysis was used to calculate the cumulative risk of re-treatment, adjusted for loss to followup. RESULTS: A total of 78 patients received transurethral microwave thermotherapy and 66 underwent transurethral prostatic resection. Median followup was 33 months. In the thermotherapy group mean maximum urinary flow rate improved from 9.2 ml. per second at baseline to 15.1, 14.5 and 11.9 ml. per second at 1, 2 and 3 years, and mean I-PSS decreased from 20 to 8, 9, and 12, respectively. In the resection group the corresponding numbers for maximum urinary flow rate were 7.8, 24.5, 23.0 and 24.7 ml. per second at 1, 2 and 3 years, and for I-PSS were 20, 3, 4 and 3, respectively. At 36 months, 14 patients in the thermotherapy and 8 from the resection groups underwent re-treatment, and the cumulative risk was 19.8% (95% confidence interval 10.4% to 29.3%) and 12.9% (4.5% to 21.3%), respectively (p = 0.28). CONCLUSIONS: Transurethral microwave thermotherapy and transurethral prostatic resection achieve durable improvement in patients with lower urinary tract symptoms suggestive of bladder outflow obstruction, while the magnitude of improvement is higher with resection. The repeat thermotherapy is based on failure of therapy whereas repeat resection is based on complications of therapy.

Aged↗
PubMed2001

Low-power microwave disinfection of soft contact lenses.

PURPOSE: To evaluate the effectiveness of low-power microwave irradiation on the disinfection of contaminated contact lenses. METHODS: We infected 24 soft contact lenses with Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa. Each contact lens was placed into a vial containing 10 mL of contaminated, non-preserved saline. Each vial was then exposed to 2, 4, 6, 9, 12, 15, or 18 minutes of microwave irradiation in an oven (2,450 MHz 600W) set at 10% power. RESULTS: We found all contact lenses to be disinfected after 15 minutes of exposure. All lenses remained hydrated and revealed no apparent damage when examined under the slit-lamp biomicroscope. CONCLUSIONS: Low level microwaving in a home microwave oven can result in effective and non-damaging disinfection of soft contact lenses.

Contact Lenses, Hydrophilic↗
PubMed2000

[Microwave effect on immunological response of chronic limb lymphedema].

OBJECTIVE: To observe the character of local and systemic immune responses in chronic limb lymphedema, and to investigate the effect of microwave on immunological response. METHODS: From November 1996 to February 1998, 27 patients with chronic limb lymphedema were adopted in this study. Among them, there were 11 males and 16 females, the average age was 36.6 years. These patients were classified as the experimental group and 10 healthy volunteers as the control group. Before and after microwave heating and bandaging treatment, T and B lymphocyte in peripheral blood and skin infiltrating cells in the patients and volunteers were detected and phenotyped with alkaline phosphatase-anti-alkaline phosphatase(APAAP) and avidin biotin peroxidase complex (ABC) immunohistochemical methods respectively. RESULTS: There were decreases of CD4+ T lymphocyte and the ratio of CD4+/CD8+ in peripheral blood and predominant dermal perivascular T lymphocyte infiltration in chronic limb lymphedema patients. After two courses of microwave heating and bandaging treatment, it was found that the number of CD4+ T lymphocytes increased and the ratio of CD4+/CD8+ was restored to normal levels, and dermal perivascular T lymphocyte infiltration decreased greatly. CONCLUSION: Microwave heating and bandaging treatment can modulate the systemic and local immunological imbalance of chronic limb lymphedema.

Adolescent↗
PubMed2001

[Ultrastructural change of rabbit lens epithelial cells induced by low power level microwave radiation].

OBJECTIVE: To study the ultrastructural change of rabbit lens epithelial cells with transmission electron microscope and to observe whether low power level microwave can induce the injury of rabbit lens. METHODS: Eight rabbit eyes were exposed to 10 mW/cm(2) low power level microwave radiation for 30 hours. Transmission electron microscope was used to observe the ultrastructural changes of the lens epithelial cells. The other eye was served as self-control. RESULTS: The ultrastructure of exposed lens epithelial cells changed apparently. The characteristic apoptosis cell morphological changes, such as small cell size, the decreased number of mitochondria, balloon-shaped mitochondria, etc can be seen. No obvious changes can be found in the protected self-control eyes. CONCLUSIONS: The low power level microwave (10 mW/cm(2)) can induce the ultrastructural changes of rabbit lens epithelial cells, this may be the appearance of early irreversible microwave radiation injury. In regard to the pathogenic mechanism, it is necessary to perform further investigations.

Animals↗
PubMed1999

[Lipid peroxide damage in retinal ganglion cells induced by microwave].

The determination of lipid peroxide damage in the primary cultured pig retinal ganglion cells induced by microwave can provide some experience on the effect of microwave and the protection from its damage. Retinal ganglion cells were cultured in vitro and exposed to different intensities or time of microwave, and cultured for another 48 hours. The content of superoxide dismutase (SOD) and malondialdehyde (MDA) was detected. Results showed that the content of MDA was increased and SOD decreased after radiation. After 48 hours in culture, the content of MDA recovered, and SOD increased. It is concluded that microwave induced the lipid peroxide damage in primary cultured retinal ganglion cells. These damages were recoverable in certain range of intensity or time.

Animals↗
PubMed2002

[Curative effect of percutaneous microwave coagulation therapy for hepatocellular carcinoma].

OBJECTIVE: To observe the curative effect of percutaneous microwave coagulation therapy (PMCT) with 2450 MHz microwave antenna for hepatocellular carcinoma. METHODS: Under local or epidural anesthesia, a thin percutaneous microwave antenna was introduced with ultrasound guidance into the tumor in the liver for thermo-coagulation. RESULTS: Among the 97 hepatic cancer lesions in 52 patients, 61(62.9%) with phi < 3 cm were coagulated once. In follow-up of 6-12 months of these lesions, 57(93.4%) showed no recurrence by CT or MRI. Thirty-six (37.1%) with 3 cm < phi < 5 cm coagulated twice showed that 27 (75.0%) gave CR and 9 (25.0%) gave PR by CT or MRI in follow up of 6 months. There were no serious clinical side effects or complications in the PMCT patients. CONCLUSION: Percutaneous microwave coagulation therapy gives good curative effect on liver tumor with phi < 3 cm. It is partly effective on lesions 3 cm < phi < 5 cm.

Adult↗
PubMed2002

Transurethral microwave therapy in 200 patients with a minimum followup of 2 years: urodynamic and clinical results.

PURPOSE: We investigated the long-term efficacy of the second generation Targis thermotherapy device (Urologix, Inc., Minneapolis, Minnesota) for decreasing outflow obstruction caused by benign prostatic hyperplasia. MATERIALS AND METHODS: At a minimum followup of 24 months 200 patients with bladder outlet obstruction documented on urodynamics and cystoscopy document with preserved detrusor function underwent transurethral microwave therapy while under local anesthesia. In 45% of cases the general American Society of Anesthesiologists health score was 3 or greater. RESULTS: After a median observation time of 42 months (range 2 to 72) 43 patients (22%) who required additional treatment (repeat thermotherapy, transurethral prostate resection or permanent cystostomy) were excluded from further analysis, as were 15 (7.5%) who died of causes unrelated to treatment during followup and 13 (6.5%) who were lost to followup or refused followup investigations. In the 162 patients evaluated 6 months after treatment the median International Prostate Symptom Score decreased from 23 points (range 10 to 34) before treatment to 3 (range 0 to 21) and remained stable at 12 and 24 months. Median maximum flow increased from 6 ml. per second (range 1 to 15) before treatment to 14.5 (range 4 to 50) 6 months after treatment and remained stable at 12 and 24 months. Median post-void residual urine volume decreased from 170 ml. (range 35 to 720) before treatment to 17 (range 0 to 327) after 6 months and then remained unchanged. Urodynamic evaluation in the 162 patients after 6 months showed a decrease from pretreatment median detrusor opening pressure of 87.5 to 53 cm. water. Median detrusor pressure at maximum flow decreased from 86 to 58 cm. water 6 (p <0.0001). At the 24-month followup 59 of the 129 evaluable patients agreed to undergo repeat urodynamic evaluation. Pressure flow analysis in these 59 cases revealed a decrease in median minimal urethral opening pressure from 70 to 40 cm. water at 6 months and to 38 cm. water at 24 months (p <0.0001). Median detrusor pressure at maximum flow decreased significantly from the pretreatment value of 86 to 55 cm. water at 6 months and 58 cm. water at 24 months (p <0.0001). CONCLUSIONS: In patients with a good initial response to treatment, which is achieved in approximately 80%, transurethral microwave therapy provides excellent long-term subjective and objective results. Improved urinary flow, decreased post-void residual urine volume and urodynamic parameters remain stable at 2 years. Transurethral microwave therapy with second generation microwave equipment did not compromise any conventional treatment needed in the 22% of patients who were nonresponders at 6 months.

Adult↗
PubMedDate not supplied

[Effects of 460 MHz microwave radiation on Drosophila embryos under raised temperature].

Combined effect of 460-MHz microwave irradiation and increased (up to 40 degrees C) temperature on Drosophila embryos of definite age was studied. It was demonstrated that the effect of 5-min exposures to non-modulated microwaves with 6 W/kg SAR accompanied with heating is only a little stronger than at normal temperature (24.5 degrees C). Irradiation with pulse-modulated microwaves with pulse repetition rates of 6, 10, 16, and 22 p.p.s. with average SAR of 0.12 W/kg (pulsed SAR 3 W/kg) combined with increased temperature caused some changes in PID dependent on the pulse rate. At 6 and 22 p.p.s, the increase in PID was close to that observed at normal temperature while at 10 and 16 p.p.s. the microwave irradiation did not produce any noticeable effect on development of the Drosophilas.

Age Factors↗
PubMed2002

[Research and development on microwave sterilization].

This paper reviews recent research and development on microwave sterilization, including the experiments of sterilization effects, the influence of microwave radiating on the media parameters, the development of microwave sterilizers and the study of sterilization mechanism. Many results show that the method of microwave sterilization is more easy-to-perform, economical and reproducible than the conventional autoclaving method. It is necessary to study the sterilization conditions through the experiments for different media and bacteria. The research on sterilization mechanism, especially non-thermal sterilization mechanism is still a hotpoint.

Bacteria↗
PubMed2002

Percutaneous microwave coagulation therapy for lung cancer.

OBJECTIVE: To evaluate the clinical effect, CT image changes and side-effects of percutaneous microwave coagulation therapy for lung cancer. METHODS: CT-guided percutaneous puncture was performed using a needle mono-pole microwave antenna with 65W, 2 450 MHz microwave delivered in 60 seconds to 20 peripheral lung cancer patients, including 8 suffering from primary lung cancer and 12 metastatic lung cancer (totally 28 lesions). RESULTS: Sixteen patients were alive after having been followed-up for 3 approximately 24 months. All patients showed nodules decreased in size. Diminution of over 50% was observed in 13 nodules and 3, completely disappeared. The overall response rate was 57.1%. Ellipsoid shadow 3.5 cm x 2.5 cm across was observed by CT in lesions immediately after coagulation. Gasification within the coagulated area was observed in a week with a high density in the peripheral region. Consolidation was observed in 3 months and the lesion disappeared 1 year later. Complete tumor necrosis was proved by biopsy. No side-effects or complications were observed. CONCLUSION: Percutaneous microwave coagulation therapy is a new safe treatment for lung cancer, giving marked effect but minimum trauma.

Follow-Up Studies↗
PubMed1999

[A comparative study of mechanical properties of microwave-cured and conventional water bath-cured denture base resins].

OBJECTIVE: To study the mechanical properties of microwave-cured polymethyl methacrylate (PMMA) denture base resins. METHODS: Using experiment research, the mechanical properties of microwave-cured and water bath-cured PMMA materials were compared. RESULTS: The microwave-cured acrylic strips had equal or better mechanical properties than conventionally processed strips. CONCLUSION: The microwave-cured denture materials satisfies the requirements of the prosthetic clinic.

Biomechanical Phenomena↗
PubMed2002

Study of low-intensity 2450-MHz microwave exposure enhancing the genotoxic effects of mitomycin C using micronucleus test and comet assay in vitro.

OBJECTIVE: To determine the interaction between 2450-MHz microwaves (MW) radiation and mitomycin C (MMC). METHODS: The synergistic genotoxic effects of low-intensity 2450-MHz microwave and MMC on human lymphocytes were studied using single cell gel electrophoresis (SCGE) assay (comet assay) and cytokinesis-blocked micronucleus (CBMN) test in vitro. The whole blood cells from a male donor and a female donor were either only exposed to 2450-MHz microwaves (5.0 mW/cm2) for 2 h or only exposed to MMC (0.0125 microgram/mL, 0.025 microgram/mL and 0.1 microgram/mL) for 24 h; and the samples were exposed to MMC for 24 h after exposure to MW for 2 h. RESULTS: In the comet assay, the comet lengths (29.1 microns and 25.9 microns) of MW were not significantly longer than those (26.3 microns and 24.1 microns) of controls (P > 0.05). The comet lengths (57.4 microns, 68.9 microns, 91.4 microns, 150.6 microns, 71.7 microns, 100.1 microns, 145.1 microns) of 4 MMC groups were significantly longer than those of controls (P < 0.01). The comet lengths (59.1 microns, 92.3 microns, 124.5 microns, 182.7 microns and 57.4 microns, 85.5 microns, 137.5 microns, 178.3 microns) of 4 MW plus MMC groups were significantly longer than those of controls too (P < 0.01). The comet lengths of MW plus MMC groups were significantly longer than those of the corresponding MMC doses (P < 0.05 or P < 0.01) when the doses of MMC were > or = 0.025 microgram/mL. In the CBMN, the micronucleated cell (MNC) rates of MW were 5@1000 and 6@1000, which showed no difference compared with those (4@1000 and 4@1000) of controls (P > 0.05). The MNC rates of 4 MMC groups were 8@1000, 9@1000, 14@1000, 23@1000 and 8@1000, 8@1000, 16@1000, 30@1000 respectively. When the doses of MMC were > or = 0.05 microgram/mL, MNC rates of MMC were higher than those of controls (P < 0.05). MNC rates of 4 MW plus MMC groups were 12@1000, 13@1000, 20@1000, 32@1000 and 8@1000, 9@1000, 23@1000, 40@1000. When the doses of MMC were > or = 0.05 microgram/mL, MNC rates of MW plus MMC groups were much higher than those of controls (P < 0.01). MNC rates of 4 MW plus MMC groups were not significantly higher than those of the corresponding MMC doses. CONCLUSION: The low-intensity 2450-MHz microwave radiation can not induce DNA and chromosome damage, but can increase DNA damage effect induced by MMC in comet assay.

Antibiotics, Antineoplastic↗
PubMed2003

[A quantitative study on early changes in rabbit lens capsule epithelium induced by low power density microwave radiation].

OBJECTIVE: To test the safety of guidelines for limiting exposure to low power level microwave radiation and to try to explore the mechanisms of early damages induced by such radiation in rabbit lens capsule epithelial cells, using flow cytometry as a quantitative method of evaluation of these damages. METHODS: The rabbit eyes were exposed to 5 mW/cm(2) (group I) and 10 mW/cm(2) (group II) power densities of microwave for 3 h. Annexin V-PI two-color flow cytometry was used to detect the changes of rabbits lens epithelial cells, apoptosis cells and secondary necrotic cells after radiation. The other eyes served as self-controls. RESULTS: In group I, the percentage of early apoptosis cells in the experimental eyes was significantly greater than that of the controls (P < 0.01), whereas no significantly difference in the percentage of secondary necrotic cells could be observed (P > 0.05). In group II, there was no significant difference between the percentage of early apoptosis cells in experimental eyes and the controls (P > 0.05), whereas the percentage of secondary necrotic cells in the experimental eyes was significantly greater than that of the controls (P < 0.05). The percentage of secondary necrotic cells (16.2 +/- 5.6)% in group II is greater than that in group I (10.3 +/- 6.8)% (P < 0.05), though there is no significant difference in the percentage of early apoptosis cells between these two groups (P > 0.05). CONCLUSION: Low power density of microwave radiation (5 mW/cm(2) and 10 mW/cm(2)) can induce irreversible damage of rabbit lens epithelial cells in a dose-dependent manner. Therefore, the safety dosage criterion of microwave exposure needs further investigation.

Animals↗
PubMedDate not supplied

Percutaneous microwave coagulation therapy for superficial hepatocellular carcinoma on the surface of the liver.

BACKGROUND/AIMS: This study was performed to evaluate the efficacy and safety of percutaneous microwave coagulation therapy for superficial hepatocellular carcinoma located on the surface of the liver. METHODOLOGY: Among 58 cirrhosis patients with 71 hepatocellular carcinomas measuring < or = 20 mm in greatest dimension, 18 patients had a solitary superficial lesion located on the liver surface (superficial hepatocellular carcinoma group) and the other 40 patients had 53 lesions that were not in contact with the liver surface (non-superficial hepatocellular carcinoma group). All patients were treated by percutaneous microwave coagulation therapy alone and the response was assessed by using contrast-enhanced CT. The survival, tumor recurrence, and adverse effects were compared between the superficial and non-superficial hepatocellular carcinoma groups. RESULTS: The 4-year survival rates of the superficial hepatocellular carcinoma group (64.2%) and the non-superficial hepatocellular carcinoma group (58.9%) were not significantly different, and neither were the 4-year local recurrence rates (27.1% vs. 29.8%). Although there was a significantly higher incidence of severe pain during microwave irradiation in the superficial hepatocellular carcinoma group (23/47) when compared with the non-superficial hepatocellular carcinoma group (25/148), there were no differences between them in the incidence of fever or the changes in liver function after treatment. There were no serious adverse effects, such as hemorrhage or tumor cell seeding, in either group. CONCLUSIONS: Percutaneous microwave coagulation therapy can be performed safely, even in patients with superficial hepatocellular carcinoma and cirrhosis, so this method is effective for treating hepatic neoplasms regardless of the tumor location.

Adult↗
PubMedDate not supplied

[Comparative estimation of the effects of continuous and intermittent cyclical microwave radiation on the behavior of rats in the extraordinary situation].

Research has been carried out to investigate the effects of pulsed microwave exposure without pause (7 GHz, 400 pps, 100 microseconds, 70-150 mW/cm2, exposure 10 min) and pulsed interrupted cyclical microwave exposure (5 min exposure--4 min pause--5 min exposure) on learned behaviors of rats in the paradigm of extraordinary situation (the rescue of the life). It was shown that reductions in conditioned behavior after acute pulsed microwave exposure occurred at SAR of 21 W/kg (100 mW/cm2) and after cyclical pulsed microwave exposure at SAR of 28.4 W/kg (135 mW/cm2).

Animals↗