The detection of large HNO3-containing particles in the winter Arctic stratosphere.

Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere. A microphysical model of nitric acid trihydrate particles is able to simulate the growth and sedimentation of these large sizes in the lower stratosphere, but the nucleation process is not yet known. Accurate modeling of the formation of these large particles is essential for understanding Arctic denitrification and predicting future Arctic ozone abundances.

Infarction in Wolff-Parkinson-White syndrome. Evolution of Q-wave-T-wave vector concordance.

Wolff-Parkinson-White syndrome often mimics myocardial infarction. Q-wave-T-wave discordance (upright T waves in the inferior leads with inferior Q waves) is normally found in Wolff-Parkinson-White syndrome as a result of secondary repolarization changes. We evaluated Q-wave-T-wave concordance as a result of an inferoposterior infarction and documented it with electrocardiographic, enzyme, and catheterization data.

Chemotherapy of fish diseases: a review.

Fish suffer from environmental, nutritional, viral, bacterial, parasitic, and neoplastic diseases, many of which are similar to those of higher animals. The prevention and treatment of these diseases follow the same principles as diseases of other animals. Fish culture is similar to poultry husbandry in that large numbers of animals are crowded into relatively small areas, feeding is free choice, and medication for systemic infections is usually oral. External treatment of fishes is more common than of poultry, due to a higher frequency of external diseases. Many of the drugs and chemicals used in chemotherapy of fishes are the same as for higher animals. The following is a brief review of the more important drugs and their methods of administration.

Effects of the antimicrobic tiamulin on seven gram-negative bacterial fish pathogens.

In vitro and in vivo test were carried out with tiamulin and gram-negative bacterial pathogens of fish. Determination of minimum inhibitory concentration for 51 strains of seven species of gram-negative bacterial pathogens showed that only strains of Vibrio anguillarum were sensitive at 1.6-6.25 ppm, while the rest of test strains required 25- greater than 100 ppm. Control of infection was not achieved when tiamulin was fed for 14 days at 5 or 50 mg/kg to rainbow trout (Salmo gairdneri) experimentally infected with Yersinia ruckeri.

Epidermal tumors of rainbow smelt with associated virus.

Epithelial tumors of the skin occurred in landlocked populations of rainbow smelt (Osmerus mordax) in several lakes in New Hampshire (USA) during the spawning runs. Histologically, these were noninvasive epithelial cell lesions. Herpesvirus-like particles could be seen in the nucleus and cytoplasm. The lesions occurred in both males and females. Prevalence which varied annually, was as high as 30%.

Postspawning mortality of rainbow trout (Salmo gairdneri) associated with Lactobacillus.

A Lactobacillus sp. was consistently isolated from dead and moribund postspawning brood stock rainbow trout. Pathology was characterized by massive chronic inflammation throughout the abdominal cavity and formation of pseudomembranes. The bacteria were most abundant in spent testes. Repeated handling was considered to be the major stressor leading to this infection and subsequent high mortality.

Comparative susceptibility of Atlantic salmon (Salmo salar) to the enteric redmouth bacterium and Aeromonas salmonicida.

The bacterium causing enteric redmouth (ERM) and Aeromonas salmonicida were found to be equally pathogenic for fingerling Atlantic salmon (Salmo salar). Injection of 5 x 10(5) cells of ERM or A. salmonicida killed all salmon within 96 h. After a 30 min exposure to water-borne cells of the two test bacteria about one-half of the test salmon died within 14 days. Both ERM and A. salmonicida were transmitted horizontally. Results indicate that efforts should be made to prevent introduction of ERM into watersheds where Atlantic salmon occur.

Viral diseases of fish: first report of carp pox in golden ide (Leuciscus idus) in North America.

Carp pox, a putative viral disease exotic to North America, occurred in golden ide 1 yr after the fish were imported into the United States from the Federal Republic of Germany. The raised, white, plaque-like lesions, which occurred on about 5% of the fish, healed spontaneously and caused no mortality. Electron micrographs showed herpesvirus-like particles associated with lesion specimens; however, no infectious viruses were detected in tests with seven warmwater fish cell lines.

Antimicrobials and fish: a review of drugs used to treat bacterial diseases of channel catfish and rainbow trout.

The principal bacterial diseases of cultured rainbow trout (Salmo gairdneri) and channel catfish (Ictalurus punctatus), and the antibacterials used in their treatment are briefly reviewed. Gram-negative bacteria predominate, and oxytetracycline is effective in treatment of infections induced by them. The only antibacterials now registered by the US Food and Drug Administration are sulfamerazine for the treatment of furunculosis in trout, and oxytetracycline for the treatment of furunculosis in salmonids and Aeromonas and Pseudomonas infections in salmonids and catfish. Registration 9/50 is now complete for the potentiated sulfonamide Romet-30 for controlling furunculosis in salmonids. Studies on the metabolism of antibacterials in fishes are limited, and are primarily concerned with tissue residue and elimination rate.

Fine structure of an unidentified protozoon in the epithelium of rainbow trout exposed to water with Myxosoma cerebralis.

An intracellular protozoon was discovered in the epithelium of young rainbow trout (Salmo gairdneri) exposed for as short a time as 1 hr to water known to contain infective stages of Myxosoma cerebralis. Light- and electron-microscopic examination of this tissue revealed what appeared to be a proliferative stage (presumptive schizont) of a sporozoon; other possible stages in the life cycle were also observed. The relationship of this unidentified protozoon of M. cerebralis remains unresolved.

Tailoring home care services to meet physician and patient needs: a market-based approach.

The services offered by the home care division of a medical center should correspond to the needs of both physicians and patients who are to be served. This study addresses the physician segment, the primary referral source for home care. It measures both the absolute and the relative importance of a range of offerings which a home care services division provides in a mid-sized, full service, medical center.

Phase II clinical trial of carboplatin, ifosfamide, with oral mesna for metastatic breast carcinoma.

Twenty-five women with advanced breast carcinoma refractory to first-line chemotherapy entered a phase II trial to evaluate the efficacy of ifosfamide and carboplatin. Additionally the trial assessed the clinical usefulness of oral 2-mercaptoethane sulfonate (mesna) for urothelial protection. Two partial remissions were observed (8%); toxicity was significant but acceptable, with no treatment-related deaths. The combination of ifosfamide and carboplatin had little activity as the second-line treatment in our population of patients with heavily pretreated metastatic breast cancer. Oral mesna was effective for urothelial protection, permitting outpatient administration of ifosfamide.

Airborne laser infrared absorption spectrometer (ALIAS-II) for in situ atmospheric measurements of N2O, CH4, CO, HCl, and NO2 from balloon or remotely piloted aircraft platforms.

The Airborne Laser Infrared Absorption Spectrometer II (ALIAS-II) is a lightweight, high-resolution (0.0003-cm(-1)), scanning, mid-infrared absorption spectrometer based on cooled (80 K) lead-salt tunable diode laser sources. It is designed to make in situ measurements in the lower and middle stratosphere on either a balloon platform or high-altitude remotely piloted aircraft. Chemical species that can be measured precisely include long-lived tracers N(2)O and CH(4), the shorter-lived tracer CO, and chemically active species HCl and NO(2). Advances in electronic instrumentation developed for ALIAS-I, with the experience of more than 250 flights on board NASA's ER-2 aircraft, have been implemented in ALIAS-II. The two-channel spectrometer features an open cradle, multipass absorption cell to ensure minimal contamination from inlet and surfaces. Time resolution of the instrument is

Evidence that nitric acid increases relative humidity in low-temperature cirrus clouds.

In situ measurements of the relative humidity with respect to ice (RHi) and of nitric acid (HNO3) were made in both natural and contrail cirrus clouds in the upper troposphere. At temperatures lower than 202 kelvin, RHi values show a sharp increase to average values of over 130% in both cloud types. These enhanced RHi values are attributed to the presence of a new class of HNO3-containing ice particles (Delta-ice). We propose that surface HNO3 molecules prevent the ice/vapor system from reaching equilibrium by a mechanism similar to that of freezing point depression by antifreeze proteins. Delta-ice represents a new link between global climate and natural and anthropogenic nitrogen oxide emissions. Including Delta-ice in climate models will alter simulated cirrus properties and the distribution of upper tropospheric water vapor.