Terahertz Imaging and Characterization Protocol for Freshly Excised Breast Cancer Tumors

This manuscript presents a protocol to handle, characterize, and image freshly excised human breast tumors using pulsed terahertz imaging and spectroscopy techniques. The protocol involves terahertz transmission mode at normal incidence and terahertz reflection mode at an oblique angle of 30°. The collected experimental data represent time domain pulses of the electric field. The terahertz electric field signal transmitted through a fixed point on the excised tissue is processed, through an analytical model, to extract the refractive index and absorption coefficient of the tissue. Utilizing a stepper motor scanner, the terahertz emitted pulse is reflected from each pixel on the tumor providing a planar image of different tissue regions. The image can be presented in time or frequency domain. Furthermore, the extracted data of the refractive index and absorption coefficient at each pixel are utilized to provide a tomographic terahertz image of the tumor. The protocol demonstrates clear differentiation between cancerous and healthy tissues. On the other hand, not adhering to the protocol can result in noisy or inaccurate images due to the presence of air bubbles and fluid remains on the tumor surface. The protocol provides a method for surgical margins assessment of breast tumors.

A Synthesis of 1-Alkyl-3,5-dimethoxybenzenes

The reaction of 3,4,5-trimethoxybenzaldehyde or 3,4,5-trimethoxyphenyl methyl ketone with alkyl magnesium halides gives secondary or tertiary carbinols. These are converted in good yields into 1-alkyl-3,5-dimethoxybenzenes by reaction with dissolving sodium in alcohols.

The disinfection by-products dichloro-, dibromo-, and bromochloroacetic acid impact intestinal microflora and metabolism in Fischer 344 rats upon exposure in drinking water

Human consumption of chlorinated drinking water has been linked epidemiologically to bladder, kidney, and rectal cancers. The disinfection by-product (DBP) dichloroacetic acid is a hepatocarcinogen in Fischer 344 rats and B6C3F1 mice. The objective of this study is to determine the effect of the DBPs dichloro-, bromochloro-, and dibromoacetic acids (DCA, BCA, DBA) on intestinal microbial populations and their metabolism, with emphasis on enzymes involved in the bioactivation of procarcinogens and promutagens. One-month-old male Fischer 344 rats were provided water ad libitum containing 1 g/l DCA, BCA, or DBA for up to 5 weeks. At 1, 3, and 5 weeks of treatment, beta-glucuronidase (GLR), beta-galactosidase (GAL), beta-glucosidase (GLU), nitroreductase (NR), azoreductase (AR), and dechlorinase (DC) activities were determined in cecal and small and large intestinal homogenates. After 5 weeks of treatment, intestinal populations were enumerated on selective media. Cecal GAL (DCA, BCA, DBA) and GLR (DCA, DBA) activities were reduced after 1 and 3 weeks of treatment and GAL activity was elevated at 5 weeks (BCA). Large intestinal GAL (DCA, BCA) and GLU (DCA, BCA, DBA) activities were elevated after 5 weeks of treatment. Week 5 cecal AR (DCA, BCA, DBA), NR (DCA), and DC (DCA, DBA) activities were reduced. Even though some significant changes in intestinal populations were observed, use of selective media was not sensitive enough to explain fluctuations in enzyme activity. Haloacetic acids in the drinking water alter intestinal metabolism, which could influence bioactivation of promutagens and procarcinogens in the drinking water.

Smoking in hotels: prevalence, and opinions about restrictions

Exposure to high levels of environmental tobacco smoke can occur in hotels. Controversy exists about smoking regulation on licensed premises. This survey of 138 people attending one of three Newcastle hotels during 1993 found that 57 per cent of respondents were nonsmokers. Fifty-eight per cent (95 per cent confidence interval (CI) 50 to 66 per cent) of respondents in these hotels believed their health was being adversely affected by other people's smoke in the hotel. Seventy per cent (CI 62 to 78 per cent), including half the smokers, were in favour of restriction of smoking in the hotels. Most preferred the establishment of smoke-free areas to the introduction of total smoking bans in hotels. The failure of hotels to regulate smoking suggests that a legislative approach is required. The case for legislation would be strengthened by a larger study elsewhere in Australia.

Nuclear charge radius of 8He

The root-mean-square (rms) nuclear charge radius of 8He, the most neutron-rich of all particle-stable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of 6He was measured to be 2.068(11) fm, in excellent agreement with a previous result. The significant reduction in charge radius from 6He to 8He is an indication of the change in the correlations of the excess neutrons and is consistent with the 8He neutron halo structure. The experiment was based on laser spectroscopy of individual helium atoms cooled and confined in a magneto-optical trap. Charge radii were extracted from the measured isotope shifts with the help of precision atomic theory calculations.

Identification of 1-(4-methoxyphenyl)-1-methoxy-2-aminopropane diastereoisomers

A method for the assignment of erythro and threo configurations to the diastereoisomeric 1-(4-methoxy-phenyl)-1-methoxy-2-aminopropanes and related compounds based on p.m.r. data is presented and discussed.

Pyoluteorin, a synthesis

The synthesis of Pyoluteorin, an antibiotic from Pseudomonasaeruginosa is described. The method used produced in addition, an isomer 3,5-dichloro-2-(2′,6′-dihydroxybenzoyl)pyrrole, for which the name isopyoluteorin is proposed. The bromine analogue of pyoluteorin is also reported.

Cardiology services after stress testing: are there sex differences? A population-based study

To test the hypothesis that, in a population-based cohort of persons undergoing stress tests, female sex was negatively associated with the use of cardiology visits in persons with no documented coronary artery disease (CAD) but that this association did not exist when CAD was established. Sex differences in the use of invasive cardiac procedures have been clearly documented, but data on physician encounters, an integral part of care, are lacking. A population-based cohort consisting of all Olmsted County, Minnesota residents who underwent an initial stress test in 1987, 1988, and 1989 in Olmsted County was examined. Medical records were reviewed for baseline characteristics including CAD diagnosis status, test results, and cardiology visits in the year following the stress test. Regression models were constructed to determine whether sex is independently associated with the probability of a visit. In the year after stress testing, there was no difference between the sexes in the use of inpatient (OR for female sex 0.88, 95% CI 0.62-0.97, P = 0.365) and outpatient/consultative (OR for female sex 1.24, 95% CI 0.95-1.61, P = 0.6) cardiology visits. Women were, however, less likely to receive preventive cardiology visits (OR for female sex 0.77, 95% CI 0.62-0.97, P = 0.02). This was largely related to less use of preventive visits among older women with documented coronary artery disease (CAD). In the absence of documented CAD, when the stress test was positive, women were less likely to receive preventive visits. In this geographically defined population within one year after an initial stress test, there was no sex difference in the use of in-patient or out-patient visits but women were less likely to receive preventive cardiology visits in the year after stress testing. Further studies are needed to understand the reasons for and impact of these care patterns.

Physiological factors affecting drug toxicity

Physiological factors that affect the fate of drugs in the body and thereby have effects on their pharmacology and toxicology involve the systems that control absorption, distribution, metabolism, and excretion. The main factors are disease, genetics, and age. Nutritional status, sex, hormonal status (e.g., the effects of pregnancy), and circadian rhythm have important influences. Maternal toxicity will affect the fetus. The absorption and excretion of drugs are frequently reduced by diseases. Excretion is reduced by impaired renal function, often found in the elderly, which may increase the toxic response. Distribution is affected by body weight and build, for example, the proportion of fat. The disposition of many drugs has been shown to be significantly influenced by circadian rhythms such that therapeutic doses may exhibit toxicity if administered at an inappropriate time of day. Metabolism is modified by environmental influences including previous food and drug experience, and various factors such as age, sex, and disease. Intersubject variations in drug disposition can be very great with possibly severe consequences for the individual; in this regard, knowledge of genetic polymorphism in drug metabolizing enzymes is rapidly increasing. The toxicology of a drug may be profoundly affected by a particular disease state, for example, the administration of a drug that might be a tumor promoter when a cancerous or precancerous condition exists. These effects are illustrated with examples from the literature and recent studies undertaken in the Bureau of Drug Research.

Pyruvate dehydrogenase activity in liver and brown fat of the developing rat

The total activity of pyruvate dehydrogenase (EC 1.2.4.1) and the fraction of the enzyme in the active form were assayed in brown fat and liver throughout the development of the rat. In brown adipose tissue, the total activity increased until the late suckling period. After weaning, a decrease was noted. The fraction of the enzyme in the active form did not increase until after 10 days of age, reached its highest level in the late suckling period and remained at this level after weaning. Pyruvate dehydrogenase in liver decreased in both total activity and percentage activity in the early neonatal period. Both parameters increased after this period, reaching their highest levels in the late suckling period. In both fetal liver and fetal brown fat, the total activity of pyruvate dehydrogenase was increased by in vitro incubation with insulin.

Metabolic O-demethylation of 3,4-dimethoxyamphetamine in vivo in dog and monkey

1. The disposition of the hallucinogen 3,4-dimethoxyamphetamine in vivo was examined in dogs and monkeys. 2. O-Demethylation is important since 3-O-methyl-alpha-methyldopamine (3-methoxy-alpha-methyltyramine) was found in the urine of both species, and traces of alpha-methyldopamine were found in the urine of dogs. 3. Also found in the urine of dogs were 1-(3,4-dihydroxyphenyl)propan-2-one and 3,4-dihydroxybenzoic acid, which are side-chain modified metabolites of alpha-methyldopamine. 4. 1-(3-Methoxy-4-hydroxyphenyl)propan-2-one, a side-chain modified metabolite of 3-O-methyl-alpha-methyldopamine, was present in the urine of both dogs and monkeys. 5. The 3-O-demethylated isomers 4-O-methyldopamine and 1-(3-hydroxy-4-methoxyphenyl)propan-2-one were not detected.

Self-powered, light-controlled, bioresorbable platforms for programmed drug delivery

Degradable polymer matrices and porous scaffolds provide powerful mechanisms for passive, sustained release of drugs relevant to the treatment of a broad range of diseases and conditions. Growing interest is in active control of pharmacokinetics tailored to the needs of the patient via programmable engineering platforms that include power sources, delivery mechanisms, communication hardware, and associated electronics, most typically in forms that require surgical extraction after a period of use. Here we report a light-controlled, self-powered technology that bypasses key disadvantages of these systems, in an overall design that is bioresorbable. Programmability relies on the use of an external light source to illuminate an implanted, wavelength-sensitive phototransistor to trigger a short circuit in an electrochemical cell structure that includes a metal gate valve as its anode. Consequent electrochemical corrosion eliminates the gate, thereby opening an underlying reservoir to release a dose of drugs by passive diffusion into surrounding tissue. A wavelength-division multiplexing strategy allows release to be programmed from any one or any arbitrary combination of a collection of reservoirs built into an integrated device. Studies of various bioresorbable electrode materials define the key considerations and guide optimized choices in designs. In vivo demonstrations of programmed release of lidocaine adjacent the sciatic nerves in rat models illustrate the functionality in the context of pain management, an essential aspect of patient care that could benefit from the results presented here.

Dietary Fusarium moniliforme culture material induces in vitro tumor necrosis factor-alpha like activity in the sera of swine

Sera obtained from a group of pigs (n = 5) fed a diet amended with fumonisin containing Fusarium moniliforme culture material was used to determine the levels of Tumor Necrosis Factor-Alpha (TNF) activity by a functional bioassay utilizing the TNF sensitive WEHI 140 mouse fibrosarcoma cell line. Two pigs developed signs consistent with pulmonary edema which was confirmed by pathologic examination in only one pig. Significant, time dependent increases in TNF-like activity were observed in all pigs during the five days of the trial. Another group of pigs (n = 5) was given a defined daily dose of the same culture material by gastric intubation. Two pigs developed fulminant pulmonary edema and sharp increases in TNF activity were observed during the 3 days of the trial in all pigs. In both cases the activity was not abrogated by addition of a neutralizing anti-human TNF monoclonal antibody suggesting that other factors may have been responsible for these effects, possibly the increased levels of sphingoid bases in the serum. Since the pig has become an important model in the study of TNF mediated endotoxic shock, these studies illustrate the relevance of certifying the absence of this important mycotoxin from corn based animal diets, specially if functional assays are used to monitor the activity of TNF in serum.