Cigarette-smoking characteristics and interest in cessation in patients with head-and-neck cancer.

Purpose: Many patients diagnosed with head-and-neck cancer are current or former smokers. Despite the well-known adverse effects of smoking, continuation of smoking during cancer treatment is associated with reduced efficacy of that treatment and with cancer recurrence. In the present study, we examined smoking characteristics in patients with head-and-neck cancer near the time of cancer treatment. Methods: A prospective cohort of patients with head-and-neck cancer who attended a dental oncology clinic before receiving cancer treatment at a regional cancer centre were invited to participate in a study that involved completing an interviewer-administered questionnaire to assess smoking characteristics, intention to quit, motivation to quit, and strategies perceived to potentially aid in successful cessation. Results: The study enrolled 493 ever-smokers, with a response rate of 96.1% and a self-reported current smoker rate of 37.1% (n = 183). Most of the current smokers reported high nicotine dependence, with 84.7% (n = 155) indicating a time to first cigarette of 30 minutes or less. Most had previously attempted to quit smoking (77.0%), and many had prior unsuccessful quit attempts before resuming smoking again. Most were interested in quitting smoking (85.8%), and many (70.5%) were seriously considering quitting smoking within the subsequent 30 days. Conclusions: Patients with head-and-neck cancer reported high nicotine dependence and high interest in cessation opportunities near the time of treatment for cancer. Those results might provide support for provision of smoking cessation opportunities.

Potential use of a novel lipase from Aspergillus carneus in deacetylation reactions.

A novel lipase from Aspergillus carneus has been used in organic solvents for efficient regioselective and chemoselective deacetylation of the peracetates of polyphenolic aromatic ketones, esters and amides. A reversal of regioselectivity was observed as compared with the results obtained during deacetylation with porcine pancreatic lipase (PPL).

Association and release of prostaglandin E1 from liposomes.

PGE1-lipid interactions were studied in several liposome systems. Data from both circular dichroic (CD) measurements and differential scanning calorimetry (DSC) indicated that PGE1 in the protonated form seeks the less polar environment of the lipid bilayer. CD measurements made on PGE1 in solution showed that the wavelength of maximum absorbance red shifted approximately 8 nm with decreasing solvent polarity. The CD spectrum of liposomal PGE1 prepared in pH 4.5 but not pH 7.2 buffer was also red shifted. There was no red shift in the CD spectrum of PGE1 detected at pH 4.5 in the absence of phospholipid. DSC measurements on DSPC bilayers prepared with 5 mol% PGE1 at pH 4.5 but not pH 7.2 revealed an almost complete loss of the pre-transition as well as broadening of the main phase transition. The amount of 3H-PGE1 initially associated with EPC, POPC or DSPC liposomes was determined using size exclusion filters and centrifugation. This amount was found to be dependent on the pH of the buffer (pH 4.5 >> pH 7.2) and fluidity of the bilayer (EPC = POPC > DSPC), but independent of the lamellarity of the liposome. In all cases, addition of cholesterol reduced the amount of PGE1 associated with the liposome. The time-dependent release of PGE1 from the liposomes was determined by rapidly diluting the sample 100-fold into pH 7.2 buffer. Lipid saturation was a key factor influencing this release. Gel-phase liposomes of DSPC showed a rapid initial release (t(1/2) < 2 min) of PGE1, corresponding to the amount in the outer monolayer, followed by a very slow, almost negligible release of the remaining PGE1. A rapid initial release also occurred in fluid-phase membranes, followed by a more gradual release of the remaining PGE1 over several hours. This release rate could be slowed by increasing the lamellarity of these liposomes, or adding cholesterol to decrease the fluidity of the membrane.

Prospective double-blind randomized study of the effects of four intravenous fluids on platelet function and hemostasis in elective hip surgery.

A prospective randomized double-blind study was performed to determine the effects of three colloids, Haemaccel, Gelofusine and albumin, and also saline on platelet activation, platelet aggregation (induced by adenosine diphosphate (ADP), epinephrine, collagen) platelet agglutination by ristocetin and other hemostatic variables in 55 patients undergoing primary unilateral total hip replacement. The fluids were administered according to normal clinical practice and assessments were made immediately before, at the end, and 2 h after the end of surgery. Surgery was accompanied by thrombin generation (increases in thrombin/antithrombin III complex, prothrombin F1 +2 fragment) platelet activation (betaTG) and compromised coagulation. Generally, the platelet activation appeared to result in platelet desensitization and brought about a persistent reduction in platelet aggregation to ADP and epinephrine, irrespective of the fluid used. Additionally, Haemaccel and Gelofusine inhibited ristocetin-induced platelet agglutination and albumin inhibited collagen-induced platelet aggregation. Gross inhibitory effects of Haemaccel that had been predicted from an earlier in vitro study did not occur. Particular fluids had selective additional effects on the hemostatic system. Albumin infusion served to maintain plasma albumin at normal concentrations postsurgery. The two gelatin preparations, Haemaccel and Gelofusine, maintained plasma viscosity. All three colloids led to a transient increase in activated partial thromboplastin time postsurgery and also a transient fall in the concentration of factor VIII, which were accompanied by a transient increase in bleeding time, but there was no measurable increase in blood loss. Inhibition of platelet aggregation by certain colloids may provide additional protection against the increased thrombotic risk in patients following major surgery.

Helical antenna arrays for interstitial microwave thermal therapy for prostate cancer: tissue phantom testing and simulations for treatment.

Interstitial microwave therapy is an experimental treatment for prostate cancer. The objective of this work was to measure the power deposition (specific absorption rate, SAR) patterns of helical microwave antennae both individually and in array patterns that would be useful for clinical treatment protocols. Commercial helical antenna 3D SAR patterns were measured in muscle equivalent phantoms using a thermographic technique. Two array patterns were tested: a 'square' and a 'crescent' array, both surrounding the urethra. To assess the feasibility of pre-treatment planning, the measured SAR patterns were input to a treatment planning computer simulation program based on a series of trans-rectal ultrasound images from a prostate cancer patient. The simulation solved the Pennes linear bioheat heat transfer equation in prostate tissue, with the aim of achieving a target of 55 degrees C at the prostate periphery while not allowing normal surrounding tissues (bladder, urethra, rectum) to rise above 42 C. These criteria could not be met with the square array but they could be met with the crescent array, provided that the prostate was first dissected away from the rectum. This can be done with a procedure such as 'hydrodissection', where sterile saline is injected to separate the prostate and rectum. The results of these SAR measurements and heat transfer simulations indicate that arrays of helical antennae could be used for safe and effective thermal therapy for prostate cancer.

Assessment of the lymphocyte response to silicone.

The biocompatibility of silicone is once again the focus of increased interest. Long considered inert, silicone has now been reported to be responsible for macrophage inhibition in rats and to possibly cause adjuvant disease in humans, and the related compound silica has elicited an antibody response in mice. The present study evaluates lymphocytic response to silicone as expressed by the demonstration of immunologic memory, or changes in specific lymphocyte subpopulations. Thirty-six female Lewis rats (250 gm body weight) were used as test animals. Group 1 (n = 12) was injected subcutaneously with 2.5 ml Freund's Complete Adjuvant (FCA) alone. Group 2 (n = 12) was injected with 2.5 ml FCA sonicated with silicone gel. Group 3 (n = 6) was injected with 2.5 ml FCA, and at 4 weeks, gel-filled silicone implants were placed subcutaneously. Group 4 (n = 6) was injected with 2.5 ml FCA sonicated with silicone gel, and gel-filled silicone implants were placed at 4 weeks. An additional group of six rats (group 5) served as control for the experimental animals, and a group of four rats (group 6) served as naive control. Groups 1 and 2 were sacrificed at 4 weeks, and splenic lymphocytes were obtained for lymphocyte transformation assays performed against silicone. Assays also were run with the addition of the known mitogens Con A, PHA, LPS, and pokeweed. Cytofluorographic analysis of pan-T, T-helper, T-suppressor, and B-cell populations was performed. Groups 3, 4, 5, and 6 were harvested at 8 months, and splenic lymphocytes were subjected to lymphocyte transformation assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Retinopathy of prematurity and surfactant treatment.

PURPOSE: Surfactant therapy in premature infants has reduced the severity of respiratory distress syndrome (RDS), thus leading to a reduction in mortality. However, the anticipated effect of surfactant therapy on the incidence and severity of retinopathy of prematurity (ROP) is ambiguous. The acute rise in PaO2 and the increased survival of low-birth-weight infants may augment the risk of ROP, whereas their improved health and respiratory status may lower it. METHODS: We reviewed the findings of sequential ophthalmologic examinations performed in our neonatal intensive care unit. Premature infants of gestational age under 32 weeks and weighing less than 1500 g at birth who received surfactant treatment were compared with a group of historical controls consisting of premature infants of the same mean birth weight and gestational age who did not get this supplement. RESULTS: ROP was present in 13 (65%) of the 20 surfactant-treated babies, and threshold disease was noted in six (30%). In the historical control group, 20 (77%) of 25 infants had ROP, of whom 10 (40%) were treated for threshold disease. These differences were not statistically significant. CONCLUSION: Surfactant therapy was not associated with an increased incidence of ROP in our series.

Patient age and general dentists' treatment decisions.

To test whether a patient's age plays a role in dentists' treatment planning decisions, a convenience sample of 159 general dentists attending a state dental society annual meeting was presented a vignette including intra-oral photographs, a brief case history and clinical diagnosis of a patient. The patient was partially dentate, and was described as having irreversible pulpitis of tooth #19. Three versions of the vignette were developed, with identical materials and information except for the patient's age (either 44, 65, or 84 years), and were randomly assigned to the participating dentists who were asked to develop a treatment plan for the patient's mandibular arch. The dentists planned limited therapy for the 84 year old because of their assumptions about the patient's brief life expectancy, cost, concern about the inability of the patient to tolerate extensive treatment, and a low cost/benefit ratio. These findings suggest that a patient's age influences general dentists' treatment planning decisions, perhaps limiting the treatment options offered to older adults. Additional research is necessary to further test these associations.

Developing a CTCAEs patient questionnaire for late toxicity after head and neck radiotherapy.

PURPOSE: Patient-based reporting of symptoms is increasingly important in providing treatment toxicity information. However, observer-based scoring systems such as the CTCAEs which incorporate the LENT-SOMA scales are not adapted for patient-based reporting. We aim to (1) report the late toxicity in patients following head and neck radiotherapy using a LENT-SOMA patient-based questionnaire, (2) describe how the responses help to improve the questionnaire and (3) adapt the questionnaire for patient reporting using CTCAEs. METHODS: A 31-item LENT-SOMA patient questionnaire was administered prospectively to 220 patients pre-treatment and at eight time periods post-radical head and neck radiotherapy over 3 years. Exploratory factor analysis was carried out and questionnaire reliability was evaluated using Cronbach's alpha coefficient. RESULTS: At 3-years follow-up, grade 3/4 toxicity was recorded for xerostomia (44%), hoarseness (14.3%), altered taste (6.1%) and oropharyngeal pain (1.9%). Factor analysis indicated that questionnaire division according to anatomical sub-site was reasonable. Cronbach's alpha was 0.851 (95% CI: 0.820-0.883) indicating high reliability. Good compliance was obtained with all questions except for the 'weight loss' item. A satisfaction survey showed that the questionnaire was clear and concise. Teeth and mandible sections have been removed. Dietary change due to xerostomia has been incorporated in line with CTCAEs. LENT-SOMA scoring of analgesic needs and dysphagia not described in CTCAEs were found useful and have been retained. CONCLUSIONS: The questionnaire has enabled reporting of late toxicity and the responses have enabled refinement of the questionnaire. It is reliable, feasible and has been validated for patient-based collection of CTCAEs late toxicity data.

Determination of measles, mumps, and rubella immunization status using oral fluid samples.

OBJECTIVE: To determine if oral fluid samples can be used to reliably assess protective blood levels of antibodies to measles, mumps, and rubella. DESIGN: A comparison of matched serum and oral fluid samples from asymptomatic subjects in enzyme-linked immunosorbent assays for measles, mumps, and rubella antibodies. A longitudinal study compared matched serum and oral fluid samples from 11 subjects after measles-mumps-rubella vaccination. SETTING: Five US clinical sites with samples tested at the reporting laboratory. PARTICIPANTS: A total of 157 asymptomatic subjects including 55 subjects younger than 18 years. MAIN OUTCOME MEASURES AND RESULTS: The presence of antibodies in oral fluid specimens correlated with that in serum with the following levels of sensitivity and specificity: measles, 97% and 100%, respectively; mumps, 94% and 94%, respectively; rubella, 98% and 98%, respectively. Longitudinal studies of subjects after vaccination showed similar seroconversion profiles in oral fluid and serum samples. CONCLUSION: Protective blood levels of antibodies to measles, mumps, and rubella can be assessed by means of an oral fluid sample with good reliability.

Measurement of the thermal conductivity of polyacrylamide tissue-equivalent material.

The purpose of this work was to measure the thermal conductivity of polyacrylamide (PAG) and compare it with previously reported values. Polyacrylamide phantoms play an important role in the development of hyperthermia and high-temperature thermal therapies based on electromagnetic (EM) radiation by providing a material that mimics the electrical and thermal properties of human tissue. The thermal properties of PAG have, up until now, not been thoroughly investigated and at least two significantly different values have been published. In this study, the thermal conductivity of polyacrylamide was measured from the steady state temperature drop across samples exposed to a known heat flux. The measured conductivity was 0.56 +/- 0.047 W m(-1) degrees C(-1). To validate the correct set of thermal properties for polyacrylamide, simple heating experiments were performed in a PAG phantom and then simulated using a finite element numerical model that incorporated the measured thermal conductivity along with literature values for specific heat and density. Temperature predictions from the model agreed with average temperatures measured in the phantom to within 1 SD of the measured temperatures.

The effects of prior exposure to silicone on capsule formation, histology, and pressure.

Investigations into the effects of prior silicone exposure on subsequent capsule formation around silicone implants assume particular relevance in light of the exponential increase in the medical application of polymers such as silicone. The inert nature of silicone has been in question with regard to its effects on the immune system, specifically whether or not it may act as a hapten or antigen. The present study analyzes the effects of prior silicone exposure on subsequent capsule formation, histological consistency, and pressures when an animal is reexposed to a silicone implant. Twelve female Lewis rats (body weight 250 g) were randomly divided into two groups. Group 1 (n = 6) rats were subcutaneously injected with 2.5 ml of Freund's Complete Adjuvant, Group 2 (n = 6) rats were injected with an equal volume of adjuvant sonicated with silicone gel. At 4 weeks a gel-filled silicone implant was placed subcutaneously in each animal. Capsule pressures were obtained at 4 months and the capsules from 3 rats from Group 2 were excised and examined microscopically. Pressures were measured again at 8 months and all remaining capsules were excised and examined. No statistically significant differences were noted when comparing two profiles over time between silicone-exposed and nonexposed animals in regard to capsule thickness or capsule pressure. However, capsule pressures were significantly lower at 8 months than at 4 months in both groups (p less than 0.034). In this model, significant reductions in capsule pressure were noted in both groups over time, but prior exposure to silicone did not appear to alter capsule histology, thickness, or pressure.

An in vitro study on the effect of UVA radiation on human gingival fibroblasts.

The recent availability of a 99.9% UVA source has made possible studies that show that low energy wavelengths, previously considered innocuous, significantly affected wound healing in hairless guinea pigs. Decreased wound tensile strength and a slower rate of wound contraction in irradiated animals were among the changes noted. Because of their advocated role in the wound healing process, fibroblasts were chosen to study the effects of pure UVA exposure at a cellular level. 3H-thymidine uptake levels were measured in 8 groups of fibroblast cultures (12 samples/group). The cultures were exposed to varying concentrations of pure UVA. Previously incorporated 14C-thymidine levels were used to compensate for differences in cell numbers between samples. At a fluence of 3.65 x 10(-3) watts/cm2, a significant decrease in 3H-thymidine incorporation (compared to controls) was seen for all exposure periods and there was a dose-dependent decrease only in 3H-thymidine uptake for cells exposed to 1-4 min of UVA. Using post-exposure incubations of 2-16 h, a time-dependent recovery of 3H-thymidine uptake was also demonstrated, from 40% of control at 4 h, to 75% at 8 h, and 99% at 16 h. The near-complete recovery at 16 h was seen in exposures up to 2.73 joules/cm2 (12 min), whereas higher concentrations showed only partial recovery. These studies demonstrated the deleterious, though reversible, effects of UVA on fibroblasts and suggest a possible pathophysiologic process for UVA's effect on wound healing in this animal model.