Randomized trial of radiotherapy plus concurrent-adjuvant chemotherapy vs radiotherapy alone for regionally advanced nasopharyngeal carcinoma.

BACKGROUND: Current practice of adding concurrent-adjuvant chemotherapy to radiotherapy (CRT) for treating advanced nasopharyngeal carcinoma is based on the Intergroup-0099 Study published in 1998. However, the outcome for the radiotherapy-alone (RT) group in that trial was substantially poorer than those in other trials, and there were no data on late toxicities. Verification of the long-term therapeutic index of this regimen is needed. METHODS: Patients with nonkeratinizing nasopharyngeal carcinoma staged T1-4N2-3M0 were randomly assigned to RT (176 patients) or to CRT (172 patients) using cisplatin (100 mg/m(2)) every 3 weeks for three cycles in concurrence with radiotherapy, followed by cisplatin (80 mg/m(2)) plus fluorouracil (1000 mg per m(2) per day for 4 days) every 4 weeks for three cycles. Primary endpoints included overall failure-free rate (FFR) (the time to first failure at any site) and progression-free survival. Secondary endpoints included overall survival, locoregional FFR, distant FFR, and acute and late toxicity rates. All statistical tests were two-sided. RESULTS: The two treatment groups were well balanced in all patient characteristics, tumor factors, and radiotherapy parameters. Adding chemotherapy statistically significantly improved the 5-year FFR (CRT vs RT: 67% vs 55%; P = .014) and 5-year progression-free survival (CRT vs RT: 62% vs 53%; P = .035). Cumulative incidence of acute toxicity increased with chemotherapy by 30% (CRT vs RT: 83% vs 53%; P < .001), but the 5-year late toxicity rate did not increase statistically significantly (CRT vs RT: 30% vs 24%; P = .30). Deaths because of disease progression were reduced statistically significantly by 14% (CRT vs RT: 38% vs 24%; P = .008), but 5-year overall survival was similar (CRT vs RT: 68% vs 64%; P = .22; hazard ratio of CRT = 0.81, 95% confidence interval = 0.58 to 1.13) because deaths due to toxicity or incidental causes increased by 7% (CRT vs RT: 1.7% vs 0, and 8.1% vs 3.4%, respectively; P = .015). CONCLUSIONS: Adding concurrent-adjuvant chemotherapy statistically significantly reduced failure and cancer-specific deaths when compared with radiotherapy alone. Although there was no statistically significant increase in major late toxicity, increase in noncancer deaths narrowed the resultant gain in overall survival.

The effect of acidification on the determination of elemental carbon, char-, and soot-elemental carbon in soils and sediments.

We studied the influence of acid pretreatment on the effective distinction between elemental carbon (EC) and organic carbon (OC), and between char-EC and soot-EC. Though widely employed in the pretreatment of soils and sediments for EC quantification, the use of HCl, HF, and HNO(3) could decrease soot thermal stability as acid remains, leading to an underestimation of soot-EC by thermal methods. We compared thermal optical reflectance (TOR) measurements of EC concentrations in char reference materials and in lacustrine and marine sediments following pretreatment with various acids. The results showed that pretreatment with 2M HCl, concentrated HNO(3), 7 M HNO(3), and 1 M HNO(3) did not result in EC oxidation. However, hot concentrated HNO(3) oxidized EC significantly, leading to lower concentrations of EC, char-EC and soot-EC. By comparing the removal of potentially interfering materials, which contain little fire-derived carbon, with different acid pretreatments, we recommend the HCl-HF-HCl and concentrated (not hot) HNO(3)-HF-HCl pretreatments for the determination of EC, char-EC, and soot-EC in soils and sediments using the TOR method.

Rapidly progressive necrotising fasciitis following a stonefish sting: a report of two cases.

Two patients developed rapidly progressive necrotising fasciitis after being stung by a stonefish. Both were given a hot-water bath for pain relief. The hot water may have accelerated bacterial growth and the consequent development of necrotising fasciitis. Vibrio vulnificus was cultured from one patient. It is recommended that patients should receive high dose of oral and intravenous antibiotic prophylaxis for vibrio prevention. Antibiotics should be given before or during, not after, a hot-water bath, and the patient's condition should be monitored closely.

Dual-peak dose measurement for radiochromic films by a newly developed spectral microdensitometer.

Radiochromic film (RCF) dosimetry is usually based on densitometric methods which use an analyzing light source of a fixed or a broad spectrum of wavelengths. These methods have not exploited the sensitivity of the dose response of the RCF otherwise attainable by using a light source with wavelengths peaked at the two absorption peaks in the absorption spectrum of the RCF. A new algorithm of dual-peak dose measurement for the RCF has been proposed in this paper to make use of these dual absorption peaks to achieve the maximum attainable sensitivity. This technique relies on the measurement of the transmittance of the RCF at the wavelength of the major and minor absorption peaks, respectively. The dual-peak dose measurement is accomplished with the aid of a novel spectral microdensitometer developed in our Institute. The microdensitometer utilizes a monochromator to provide a light source of which the wavelength can be matched precisely to the wavelength of the absorption peaks of the RCF. The doses obtained at these wavelengths are fed into a weighted objective function and an optimum dose is searched by minimizing the objective function to give the best estimate of the dose deposited on the film. An initial test shows that there is a good agreement between the estimated and actual dose deposited; and the maximum discrepancy was found to be less than 1%.

TEM study of the structural dependence of the epitaxial passive oxide films on crystal facets in polyhedral nanoparticles of chromium.

Nanocubes and partially truncated rhombic dodecahedral nanoparticles of Cr have been studied by electron diffraction, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. It is found that the nanoparticles of Cr are enclosed by the epitaxial passive oxide films. The oxide films on 100% truncated nanocubes of Cr with only one kind of facets, (100) facets, are face-centered cubic (fcc) structured Cr(2)O(3) with a lattice constant of 0.407nm. There are two kinds of oxide films in partially truncated nanoparticles of Cr with two kinds of crystallographic facets, (100) and (110). The same fcc Cr(2)O(3) is found on the (100) facets while the rhombohedral [Formula: see text] -Cr(2)O(3) is found on the (110) facets. This is similar to the two kinds of oxides, fcc and rhombohedral Fe(2)O(3), which have also been observed in polyhedral nanoparticles of Fe. These passive Cr(2)O(3), found in nanoparticles of Cr which have remained unchanged in water for four years, may have important implications for protective oxide films involving Cr.

Diffuse axonal injury: detection of changes in anisotropy of water diffusion by diffusion-weighted imaging.

Myelinated axons of white matter demonstrate prominent directional differences in water diffusion. We performed diffusion-weighted imaging on ten patients with head injury to explore the feasibility of using water diffusion anisotropy for quantitating diffuse axonal injury. We showed significant decrease in diffusion anisotropy indices in areas with or without signal abnormality on T2 and T2*-weighted images. We conclude that the water diffusion anisotropy index a potentially useful, sensitive and quantitative way of diagnosing and assessing patients with diffuse axonal injury.

Necrotising fasciitis of a limb.

Between January 1992 and December 1998, we treated 24 patients with necrotising fasciitis of a limb. There were 15 men and nine women with a mean age of 59.8 years (5 to 86). The infection was usually confused with cellulitis. Exquisite pain and early systemic toxicity were the most consistent clinical features. Diabetes mellitus and hepatic cirrhosis were the most commonly associated medical diseases. One third of the patients died. Those with involvement of the limbs above the knee or elbow on admission had a significantly higher rate of mortality than those with distal lesions (Fisher's exact test, p = 0.027). There was no correlation between mortality and advanced age (Student's t-test, p = 0.22) or between amputation and survival (Fisher's exact test, p = 0.39).

The effect of beam tube potential variation on gonad dose to patients during chest radiography investigated using high sensitivity LiF:Mg,Cu,P thermoluminescent dosemeters.

Optimization of X-ray beam tube potential (kVp) in radiological examinations can minimize patient dose. This research aims to investigate the effect of tube potential variation on gonad doses to patients during posteroanterior (PA) chest radiography examinations. This study was carried out using a Toshiba general purpose X-ray unit and a Rando phantom. Dose measuring equipment included an ion chamber system, a dose-area product (DAP) meter and a thermoluminescent dosemeter (TLD) reader system with high sensitivity TLD pellets of LiF:Mg,Cu,P for low level gonad dose measurement. PA chest exposures of the phantom to produce a constant exit dose were made using a standard low tube potential (range 60-100 kVp) non-grid technique and a high tube potential (range 95-150 kVp) grid technique. Entrance surface doses (ESDs) and DAPs were also included in the measurements. Effective doses (EDs) were computed from ESD and DAP measurements using NRPB-SR262 and Xdose software. Results show that with the low tube potential technique both ovary dose and testes dose increase with increasing tube potential; statistically significant correlations of r = 0.994 (p = 0.0006) and r = 0.998 (p = 0.001), respectively, were found. For both organs, doses increase at a rate of approximately 2% per kVp. With the high tube potential technique there is insignificant correlation between gonad doses and tube potential. When comparing patient doses from typical exposures made at 70 kVp (low tube potential non-grid technique) with doses from exposures made at 120 kVp (high tube potential grid technique), the high tube potential technique delivers significantly higher values for ESD, and ovary, testes and effective doses by factors of 1.7, 5.2, 5.5 and 2.7, respectively.

"Anode heel effect" on patient dose in lumbar spine radiography.

Appropriate use of the "anode heel effect" of the output beam from an X-ray tube can reduce the effective dose to patients in some common radiological examinations. We investigated the variation in radiation intensity across the X-ray beam caused by the anode heel effect, and quantified the difference in absorbed dose to critical organs resulting from lumbar spine X-ray projections carried out with the two possible orientations of the patient along the tube axis (cathode to anode). A Rando phantom and some high sensitivity thermoluminescent dosemeters (TLDs) (LiF:Mg,Cu,P) were used. With the tube axis horizontal, radiation intensity profiles, parallel and perpendicular to the axis, were measured. Lumbar spine radiographs were recorded using the Rando phantom in the standard anteroposterior (AP) and lateral projections. TLD pellets were used to measure the absorbed radiation dose at various sites corresponding to critical organ tissues (ovaries, testes, breasts, thyroid and lens). Each set of projections was recorded in two phantom orientations, first with the phantom head placed towards the cathode end of the X-ray tube, and then in the reverse direction. From the radiation intensity profile of the incident X-ray beam, the "cathode end" to "anode end" air dose ratio was found to be 1.8. In lumbar spine radiography, with the phantom head placed towards the anode end of the X-ray tube, the ovaries and testes received an average dose 17% and 12% higher, respectively, in the lateral projection, and 16% and 27% higher, respectively, in the AP projection, than those obtained in the reverse "patient" orientation. These results indicate that patients (particularly females) should always be positioned with the head placed towards the cathode end of the X-ray tube for lumbar spine radiography to achieve significant dose reductions.

Oxidation behavior of surface-modified titanium for titanium-ceramic restorations.

STATEMENT OF PROBLEM: Titanium-ceramic bonding is an unsolved problem for the current use of titanium-ceramic restorations. PURPOSE: The purpose of the study was to characterize oxide formation on titanium surfaces at porcelain sintering temperatures and to determine the effect of chromium coating methods on titanium oxide formation. MATERIAL AND METHODS: Sputter coating and electroplating methods of chromium application were compared and combined. RESULTS: Porous, weak titanium oxide formation on uncoated samples was demonstrated at porcelain sintering temperatures. Groups with chromium coating as an oxygen diffusion barrier exhibited lower oxidation rates, except samples coated by sputtering alone. Temperature effect was found to have the greatest significance on titanium oxidation rate. The overall lowest oxidation rate was located in the group that had chromium coating by the combined coating method and was oxidized at 750 degrees C. CONCLUSION: The electroplating method requires further investigation and development so that a uniform chromium layer can be deposited on titanium.

Gingival absorption of triclosan following topical mouthrinse application.

This study assessed the gingival uptake and urinary excretion of triclosan in dogs following topical applications of a mouthrinse containing 0.03% of triclosan. Five different phases were conducted to define the time course of plasma concentration. The effect of plaque on gingival absorption was also measured. Phase I: Animals' teeth were cleaned of plaque via scraping. Blood sampling time was 0-2 hours. Phase II: Plaque was not removed from the animals' teeth. Blood sampling time was 0-2 hours. Phase III: Plaque was not removed from the animals' teeth. Blood sampling time was 0-6 hours. Phase IV: Plaque was not removed from the animals' teeth. Blood sampling time was 0-12 hours. Phase V: Animals' teeth were cleaned of plaque via scraping. Blood sampling time was 0-12 hours. The test substance was administered to 1 male and 1 female dog in Phases I, II, IV and V, and to 1 male dog in Phase III. The same animals were used in each phase. On the first day of each phase, the animals were treated with distilled water for a 15-minute period. The animals were exposed daily to the test material for a 15-minute period during the remaining 7 days of each phase. The test material was administered using custom-made acrylic applicator trays to enclose the maxillar premolars and molars and gingiva of one-half of the upper jaw. A leak-proof seal along the mucogingival junction and palatal mucosa was established and maintained during the exposure period.(ABSTRACT TRUNCATED AT 250 WORDS)

Wealth transfer through voluntary death.

Today, the hopelessly ill who are insured must choose between futile treatment and prolonged morbidity. Legalizing physician-assisted death for the hopelessly ill would broaden patient choice and conserve scarce resources. To ensure that the saved resources will not be re-channeled to more futile treatments for other hopelessly ill patients, those who choose dignified passage should be allowed to determine how the saving from their refusal to a prolonged death is to be re-deployed. Converting projected entitlements into death benefits at a discount would not only reduce health-care and retirements costs but improve allocation of scarce resources.

Single dose ofloxacin in treatment of uncomplicated gonorrhoea.

78 patients (66 male and 12 female) suffering from uncomplicated gonorrhoea were randomly selected to receive a single oral dose of either 400 mg or 600 mg ofloxacin. Of the 59 patients completely followed up penicillinase-producing Neisseria gonorrhoeae strains were cultured in 15 (25.4%) and the overall cure rate was 100%. Both groups showed excellent clinical effectiveness in over 80% and adverse reactions were uncommon and transient. We conclude that a single oral dose of ofloxacin in the studied dosage regimens was highly effective and safe in the treatment of uncomplicated gonorrhoea.

Rapid GLC determination of fusaric acid in biological fluids.

A simple, sensitive GLC assay was developed for fusaric acid, the active metabolite of bupicomide, to follow the disposition of this investigational antihypertensive agent in patients undergoing therapy. Fusaric acid is efficiently extracted from biological samples, derivatized by on-column methylation, and chromatographed using flame-ionization detection. An internal standard is utilized to quantitate results. The procedure is rapid and specific for fusaric acid, and has a lower limit of sensitivity of 0.1 mug/ml. The method is suitable for supporting pharmacokinetic studies of bupicomide following therapeutic doses in animals and humans.

Phospholipid of the rat glomerular basement membrane in experimental nephrosis.

Phospholipids were found to be a constant component of rat glomerular basement-membrane preparations. The concentration fell during preparation of basement membrane by sonication of whole glomeruli, but then remained constant despite continued sonication. The proportions of the individual phospholipids were different from those of whole renal tissue or of isolated glomeruli. The basement-membrane preparations had no (Na(+)+K(+))-activated adenosine triphosphatase activity, an enzyme that is bound to plasma membranes. The concentration of lipid P was decreased on exposure in vivo or in vitro to antiserum against basement membrane; 7 days after injection of antiserum there was a change in the phospholipid composition, with a relative increase in phosphatidylcholine and a decrease in sphingomyelin content. The metabolic turnover rate of the lipid P remaining in the membrane was normal, as determined by (32)P incorporation. The loss of phospholipid was associated with decreases in the relative concentrations of hydroxyproline, hydroxylysine and glycine, and relative increases in proline, lysine, serine, threonine and valine. Administration of aminonucleoside and daunomycin produced proteinuria but did not cause a decrease in lipid P. Anticollagen and anti-lymphocyte sera that attached to the basement membrane but failed to produce proteinuria, also failed to affect the phospholipid content.