Treatment planning methodology for the Miami Multichannel Applicator following the American Brachytherapy Society recently published guidelines: the Lahey Clinic experience.

The objective of this study was to develop a standardized procedure from simulation to treatment delivery for the multichannel Miami applicator, in order to increase planning consistency and reduce errors. A plan is generated prior to the 1st treatment using the CT images acquired with the applicator in place, and used for all 3 fractions. To confirm the application placement before each treatment fraction, an AP image is acquired and compared with the AP baseline image taken at simulation.

Retrospective review of Contura HDR breast cases to improve our standardized procedure.

To retrospectively review our first 20 Contura high dose rate breast cases to improve and refine our standardized procedure and checklists. We prepared in advance checklists for all steps, developed an in-house Excel spreadsheet for second checking the plan, and generated a procedure for efficient contouring and a set of optimization constraints to meet the dose volume histogram criteria. Templates were created in our treatment planning system for structures, isodose levels, optimization constraints, and plan report.

SU-E-T-138: Quantification of Dwell Position Inaccuracy in Varian GammaMed HDR Titanium Ring Applicators.

Purpose: To quantify the dwell position inaccuracy in Titanium ring applicators and develop a test to be performed quarterly, after source exchange.

Methods: All three rings from our Titanium kit (30, 45, 60 deg.) were used for this study.

Quality assurance methodology for Varian RapidArc treatment plans.

With the commercial introduction of the Varian RapidArc, a new modality for treatment planning and delivery, the need has arisen for consistent and efficient techniques for performing patient-specific quality assurance (QA) tests. In this paper we present our methodology for a RapidArc treatment plan QA procedure. For our measurements we used a 2D diode array (MapCHECK) embedded at 5 cm water equivalent depth in MapPHAN 5 phantom and an Exradin A16 ion chamber placed in six different positions in a cylindrical homogeneous phantom (QUASAR).

Code of Ethics for the American Association of Physicists in Medicine: report of Task Group 109.

A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals.

Anniversary paper: AAPM Education Council: looking back or looking forward.

As we celebrate the 50th year of the American Association of Physicists in Medicine (AAPM), what better time to look back at our development as well as to look forward to the opportunities that lie ahead. Here the authors will review some of the achievements of the Education Council and show how the activities are helping to shape the future educational goals and opportunities of the AAPM and the medical physics profession. Much of the work of the Education Council is carried out by the various committees and subcommittees that make up the Council or have a liaison relationship with the Council.

Nitration and nitrosation of N-acetyl-L-tryptophan and tryptophan residues in proteins by various reactive nitrogen species.

Proteins are targets of reactive nitrogen species such as peroxynitrite and nitrogen dioxide. Among the various amino acids in proteins, tryptophan residues are especially susceptible to attack by reactive nitrogen species. We carried out experiments on the reactions of peroxynitrite and other reactive nitrogen species with N-acetyl-L-tryptophan under various conditions.

Formation of N-nitrosamines and N-nitramines by the reaction of secondary amines with peroxynitrite and other reactive nitrogen species: comparison with nitrotyrosine formation.

Reactive nitrogen species, including nitrogen oxides (N(2)O(3) and N(2)O(4)), peroxynitrite (ONOO(-)), and nitryl chloride (NO(2)Cl), have been implicated as causes of inflammation and cancer. We studied reactions of secondary amines with peroxynitrite and found that both N-nitrosamines and N-nitramines were formed. Morpholine was more easily nitrosated by peroxynitrite at alkaline pH than at neutral pH, whereas its nitration by peroxynitrite was optimal at pH 8.

Analysis of 3-nitrotyrosine in biological fluids and protein hydrolyzates by high-performance liquid chromatography using a postseparation, on-line reduction column and electrochemical detection: results with various nitrating agents.

Nitric oxide reacts rapidly with superoxide to form the strong nitrating agent peroxynitrite, which is responsible for much of the tissue damage associated with diverse pathophysiological conditions such as inflammation. The occurrence of free or protein-bound nitrotyrosine (NTYR) has been considered as evidence for in vivo formation of peroxynitrite. However, various agents can nitrate tyrosine, and their relative significance in vivo has not been determined due to lack of a sensitive method to analyze NTYR in tissue proteins and biological fluids.

Antiviral activity of Hawaiian medicinal plants against human immunodeficiency Virus Type-1 (HIV-1).

Hawaiian medicinal plants commonly used for the treatment of a variety of infections were screened for antiviral activity against human immunodeficiency virus type 1 (HIV-1). Sixty-one extracts derived from seventeen plants were tested for selective viral growth inhibition using the LAI (HTLV-IIIB) isolate. The greatest degree of antiviral activity was observed with aqueous extracts made from the bark of Eugenia malaccensis (L.

Anti-microbial activity and anti-complement activity of extracts obtained from selected Hawaiian medicinal plants.

Selected plants having a history of use in Polynesian traditional medicine for the treatment of infectious disease were investigated for anti-viral, anti-fungal and anti-bacterial activity in vitro. Extracts from Scaevola sericea, Psychotria hawaiiensis, Pipturus albidus and Eugenia malaccensis showed selective anti-viral activity against Herpes Simplex Virus-1 and 2 and Vesicular Stomatitis Virus. Aleurites moluccana extracts showed anti-bacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, while Pipturus albidus and Eugenia malaccensis extracts showed growth inhibition of Staphylococcus aureus and Streptococcus pyogenes.

Detection of mutagen specific adduct formation in DNA using sequencing methodology.

It has been reported that single stranded viral DNA reacts with the carcinogen, chloroacetaldehyde at specific hot spots (Premaratne et al., 1993 Int. J.

Detection of small quantities of double stranded DNA by enhanced fluorescence of substituted aldehyde modified polydeoxynucleotide-ethidium bromide complexes.

A method for the detection of small amounts of double stranded DNA by a simple incubation procedure involving the reaction of the nucleotide bases in DNA with chloroacetaldehyde is described. Following incubation, the presence of DNA may be visualized by the orange fluorescence emitted when ethidium bromide (EtBr) is added. Alternatively, the aldehyde/DNA mixture may be separated by agarose gel electrophoresis and individual double stranded DNA visualized by exposing the gel to ethidium bromide and observing the orange ultraviolet light induced fluorescence of the aldehyde modified double stranded ethidium bromide complex (Waring, M.

Enhanced mutagenic effect of a 60 Hz time-varying magnetic field on numbers of azide-induced TA100 revertant colonies.

Forty-eight hours exposure to a two Gauss (0.2 mT) rms 60 Hz time varying sinusoidal electromagnetic field increased the number of azide induced TA100 revertant colonies of Salmonella typhimurium 14% as compared with controls in the ambient < 2 milli-Gauss 60 Hz field. In the absence of the electromagnetic field, the numbers of mutant colonies grown within and outside the non-energized coil were nearly identical.

Identification of DNA adducts at specific locations by sequencing techniques.

1. A simple procedure for the accurate identification of the positions of adduct formation when viral M13mp18 single stranded DNA is treated with chloroacetaldehyde (CAA) is presented. 2.

Mutagenicity of nitric oxide and its inhibition by antioxidants.

Nitric oxide (NO) is produced both by macrophages in vivo as a physiological response to infection and by a variety of cell types as an intercellular messenger. In addition, NO and nitrogen dioxide (NO2) are significant components of many combustion processes. The ubiquitous exposure of humans to nitrogen oxides (NOx), both endogenously and exogenously, may play a significant role in the carcinogenic process due to nitrosation of amines by NOx.

Formation of mutagens during the frying of Hawaiian fish: correlation with creatine and creatinine content.

Compounds mutagenic toward Salmonella typhimurium strain TA98 in the presence of rat-liver homogenates (S9) were formed when fish flesh was fried at 199 degrees C. Three species of Hawaiian fish commonly consumed in Hawaii (skipjack tuna, Katsuwonus pelamis; yellowfin tuna, Neothunnus macropterus; and milkfish, Chanos chanos) were cooked in an electric skillet, along with samples of sole (Microstomus pacificus). Organic extracts of the fish were tested in the Ames Salmonella mutagenic assay using tester strain TA98 and S9.

Synthesis, characterization and mutagenicity of 2-nitroso-6,7-dimethoxytetrahydroisoquinoline.

The compound 6,7-dimethoxytetrahydroisoquinoline (Scheme 2, (ii] reacts with nitrous acid at ambient temperature and pH approximately 3.0 to give, in high yield the expected 2-nitroso-6,7-dimethoxytetrahydroisoquinoline (Scheme 2, (iii)). An unequivocal chemical structure of this nitroso derivative was established by high resolution mass spectrometry and 1H NMR spectrometry.

Free radical scavenging activity of papaya juice.

Papaya juice is an efficient scavenger of highly reactive hydroxyl radicals (OH.) formed during 60Co irradiation of water. The OH.

Characterization and mutagenicity of 1-nitrosotryptophol and 6-nitrotryptophol possible genotoxic substances associated with smoking and alcohol consumption.

Tryptophol (Typ) is a minor product of tryptophane metabolism in humans which is increased with alcohol consumption. Typ can react rapidly with nitrite at pH 3.0 to form 1-nitrosotryptophol (NO-Typ) in high yield.

Isolation and characterization of a novel yellow pigment from human and primate tissue.

A novel lipophilic yellow pigment has been isolated from human and primate tissue. Field-desorption mass spectrometry suggests a molecular ion of mass 645-700, and electron-impact mass spectrometry gives a major fragment ion at 603.5348, which is consistent with the elemental composition C37H69N3O3.

Colorectal cancer in Hawaiian Japanese men: a progress report.

Comparisons of Hawaiian Japanese with Japanese living in Japan identify several differences between the 2 populations. The Hawaiian Japanese are heavier and taller; they consume more fat and protein; they have higher levels of serum cholesterol, more frequent fecal mutagens, and more frequent adenomatous polyps and diverticulae. These differences offer indirect support to the concept that the consumption of a Western diet favors the development of coronary heart disease and colon cancer which occur more frequently among the Japanese in Hawaii than in Japan.