Dual-energy bone densitometry using a single 100 ns x-ray pulse.

A pulsed, portable hard x-ray source has been developed for medical imaging and flash x-ray absorptiometry. The source is powered by a Marx generator that drives a field emission x-ray tube which produces a 30-300 keV x-ray pulse of 100 ns duration. The x-ray fluence has dual-energy properties.

Short communication: renal tubular vacuolation in animals treated with polyethylene-glycol-conjugated proteins.

During toxicologic evaluation of a dimeric PEG-linked protein, tumor necrosis factor binding protein (TNF-bp), vacuolation of renal cortical tubular epithelium was seen in male and female Sprague-Dawley rats (200-300 g) given i.v. doses of 40, 20, or 10 mg/kg every other day for 3 months.

Pharmacokinetics, immunogenicity, and efficacy of dimeric TNFR binding proteins in healthy and bacteremic baboon.

Immunogenicity, pharmacokinetics, and therapeutic efficacy of three novel dimeric soluble tumor necrosis factor (TNF)-receptor I constructs [TNF-binding protein (bp)] were evaluated in 28 baboons, 12 of which were healthy and 16 were challenged with a lethal Escherichia coli bacteremia. The three constructs differed only in the number of extracellular domains of the TNF receptor I and were dimerized with polyethylene glycol. Although all three constructs had generally similar pharmacokinetics when administered to a naive animal, they differed quantitatively in their immunogenicity.

Systemic sclerosis: using high-resolution CT to detect lung disease in children.

Objective: The purpose of this study was to determine the prevalence of interstitial lung disease and the severity of disease in children with systemic sclerosis using high-resolution CT (HRCT).

Subjects And Methods: Eleven children (mean age, 11 years) with scleroderma underwent HRCT, chest radiography, and pulmonary function testing. Eight of these 11 patients also underwent follow-up HRCT.

Alterations in the reproductive patterns of female mice exposed to xenobiotics.

Chemicals, by virtue of their varied interactions with biological molecules, are expected to differ in the way they may alter female reproduction. Reproductive toxicity may reflect effects either on the female germ cells or on various maternal processes such as ovulation, implantation, pregnancy, and parturition. In either case, the ultimate manifestation of chemical toxicity on female reproduction is a decrease in the number of normal young born.

Phenolphthalein induces thymic lymphomas accompanied by loss of the p53 wild type allele in heterozygous p53-deficient (+/-) mice.

Epidemiology studies have indicated that many human cancers are influenced by environmental factors. Genetically altered mouse model systems offer us the opportunity to study the interaction of chemicals with genetic predisposition to cancer. Using the heterozygous p53-deficient (+/-) mouse, an animal model carrying one wild type p53 gene and one p53 null allele, we studied the effects of phenolphthalein on tumor induction and p53 gene alterations.

Two-generation reproductive toxicity study of dietary tributyl phosphate in CD rats.

Tributyl phosphate (TBP) was tested for reproductive toxicity in rats. Thirty weanlings/sex (F0) were exposed to TBP in the diet ad libitum at 0, 200, 700, or 3000 ppm for 10 weeks and then randomly mated within groups for 3 weeks with continued exposure. F0 parents and 10 F1 weanlings/sex/dose were necropsied, and adult reproductive organs, urinary bladders (both sexes), kidneys (males), and livers (females) were evaluated histologically.

The need for specialized training programs in palliative medicine.

Canada faces a significant and growing burden of terminal illness. There are major unresolved economic, ethical and social issues related to care at the end of life. Despite the international reputation for Canadian efforts in palliative care, the medical profession in Canada has largely failed to recognize the importance of the field, as evidenced by the lack of commitment on the part of most medical faculties at Canadian universities to developing academic strength in palliative medicine, the lack of content in the undergraduate curriculum and of postgraduate programs in palliative medicine, and the lack of support for research into end-of-life care.

Efficiency of a multilayer-coated, ion-etched laminar holographic grating in the 14.5 16.0-nm wavelength region.

The efficiency of an ion-etched laminar holographic grating was measured at near-normal incidence in the 14.5-16.0-nm wavelength range.

High-resolution CT of pediatric lung disease: imaging findings.

The HRCT findings of diseases of the pulmonary parenchyma and airways in children are often similar to those seen in adults. However, some conditions, particularly IPF, pulmonary fibrosis associated with scleroderma, and Langerhans histiocytosis, may have different presentations and a more rapid progression in children than in adults. HRCT may be helpful for assessing patients with suspected diseases of the pulmonary parenchyma or airways, particularly when radiographic findings are normal or nonspecific.

The developmental toxicity of boric acid in rabbits.

Boric acid (BA), an ingredient of many pharmaceutical, cosmetic, and pesticide products, was previously shown to induce reproductive and developmental toxicity in laboratory rodents. In this study, BA (0, 62.5, 125, or 250 mg/kg/day, po) was administered on Gestational Days (GD) 6-19 to New Zealand White rabbits (18-23 pregnant/group).

Reflectance of a wideband multilayer x-ray mirror at normal and grazing incidences.

The reflectance of a W-B(4)C multilayer mirror, with a period thickness that increased with depth into the multilayer, was measured at near-normal incidence with synchrotron radiation and at grazing incidence with Cu Kα radiation. The period thickness increased linearly from 17.9 Å at the top of the multilayer structure to 21.

Reproductive toxicity evaluation of methylethyl ketoxime by gavage in CD rats.

Methylethyl ketoxime (CAS No. 96-29-7; MEKO; 2-butanone oxime), an antioxidant agent used in paints, resins, and adhesives, was tested for reproductive toxicity in a two-generation study with CD (Sprague-Dawley) rats. Thirty-eight-week-old rats/sex/group (F0) were administered MEKO in water, by gavage, at 0, 10, 100, or 200 mg/kg/day (at a dosing volume of 2 ml/kg), 5 days/week for 10 weeks with vaginal cytology evaluation (VCE) of F0 females during the last 3 weeks of the prebreed period.

Transmittance of a thin Saran film in the 45-584-Å wavelength region.

The transmittance of a free-standing Saran film, 4260 Å thick, has been measured by means of synchrotron radiation in the 45-584-Å wavelength region. The transmittance was calculated by means of the elemental composition of the film material as determined by x-ray photoelectron spectroscopy and the optical constants as derived from atomic-scattering factors. The calculated transmittance agreed with the measured transmittance in the 45-150-Å wavelength region.

Polarization and efficiency of a concave multilayer grating in the 135-250-Å region and in normal-incidence and SeyaNamioka mounts.

A molybdenum/silicon multilayer coating was applied to a holographic ion-etched blazed grating substrate that had 2400 grooves/mm and a radius of curvature of 2.2 m. Scanning probe microscopy yielded the same surface microroughness (5 Å rms) before and after deposition of the multilayer.

Efficiency and long-term stability of a multilayer-coated, ion-etched blazed holographic grating in the 125-133-Å wavelength region.

The efficiency of an ion-etched blazed holographic grating was measured by the use of synchrotron radiation in the 125-133-Å wavelength range and at near-normal incidence. The grating had a Mo-Si multilayer interference coating that resulted in a peak normal-incidence efficiency of 13% in the second grating order and at a wavelength of 128 Å. This is the highest efficiency obtained to date from a multilayer-coated grating in this wavelength region and at normal incidence.

Normal-incidence efficiencies in the 115-340-Å wavelength region of replicas of the Skylab 3600-line/mm grating with multilayer and gold coatings.

Multilayer and gold coatings were applied to replicas of the 3600-line/mm ruled grating that was developed for the Naval Research Laboratory S082A spectroheliograph that was flown on the Skylab spacecraft. The Mo-Si multilayer coating had a peak normal-incidence reflectance of 50% at a wavelength of 136 Å. The normal-incidence efficiency of the multilayer-coated grating was measured by the use of synchrotron radiation and was compared with the efficiency of the gold-coated replica grating in the 115-340-Å wavelength region.

Potentiation of carbon tetrachloride hepatotoxicity by inhaled methanol: time course of injury and recovery.

Increases in the use of methanol (MeOH) as a transportation fuel would result in greater potential for inhalation exposure. Because oral exposure to MeOH potentiates the hepatotoxicity of carbon tetrachloride (CCl4), we examined the ability of inhaled MeOH to potentiate CCl4 hepatotoxicity and the time course of injury and recovery. Adult male F-344 rats were exposed to 0 or to 10,000 ppm MeOH by inhalation for 6 h and gavaged with 0.