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Biomedical subjects

E D Nelson

Publications and source records attributed to E D Nelson.

18 recordsLinked to original sources
PubMed2001

Dynamic air-water exchange of polychlorinated biphenyls in the New York-New Jersey Harbor Estuary.

Simultaneous measurements of polychlorinated biphenyls (PCBs) in the air and water over Raritan Bay and New York Harbor were taken in July 1998, allowing the first determinations of air-water exchange fluxes for this heavily impacted system. Average gas-phase concentrations of sigmaPCBs were 1.0 ng m(-3) above Raritan Bay and 3.1 ng m(-3) above New York Harbor. A similar gradient was observed for dissolved water concentrations (1.6 and 3.8 ng L(-1), respectively). Shallow slopes of log K(oc) vs log K(ow) plots indicated a colloidal contribution to the dissolved concentrations, and a three-phase partitioning model was therefore applied. PCBs associated with colloids ranged from 6% to 93% for trichloro- to nonachlorobiphenyls, respectively. Air-water gas exchange fluxes of sigmaPCBs exhibited net volatilization for both Raritan Bay at +400 ng m(-2) day(-1) and New York Harbor at +2100 ng m(-2) day(-1). The correction for the colloidal interactions decreased the volatilization flux of sigmaPCBs by about 15%. Net air-water exchange fluxes of PCBs are expected to remain positive throughout the year due to the large water-air fugacity gradient and relatively constant seasonal water concentrations. The volatilization fluxes are approximately 40 times greater than atmospheric deposition of PCBs via both wet and dry particle deposition, suggesting that the estuary acts as a net source of PCBs to the atmosphere year-round.

Air Pollutants↗
PubMed2001

A Fourier-transform ion cyclotron resonance study of the 3,5-didehydrophenyl cation.

The 3,5-didehydrophenyl cation has been generated in good purity via sustained off-resonance irradiation for collision-activated dissociation of 3,5-dinitrobenzoyl chloride in a Fourier-transform ion cyclotron resonance mass spectrometer. Differences in the ion-molecule reactivity of this species from that of its cyclic and acyclic isomers allowed isomeric distinction to be achieved. This study represents the first definitive identification of this fundamentally interesting, doubly aromatic ion. However, the formation of the 3,5-didehydrophenyl cation was found to be the exception rather than the rule, with most 1,3,5-substituted benzenes yielding mainly acyclic C6H3+ isomers under electron ionization conditions. This mixed ion population was attributed to isomerization of fragmentation intermediates rather than any intrinsic instability of the 3,5-didehydrophenyl cation.

Journal Article↗
PubMed2000

Thermoregulation and heat exchange in a nonuniform thermal environment during simulated extended EVA. Extravehicular activities.

BACKGROUND: Nonuniform heating and cooling of the body, a possibility during extended duration extravehicular activities (EVA), was studied by means of a specially designed water circulating garment that independently heated or cooled the right and left sides of the body. The purpose was to assess whether there was a generalized reaction on the finger in extreme contradictory temperatures on the body surface, as a potential heat status controller. METHOD: Eight subjects, six men and two women, were studied while wearing a sagittally divided experimental garment with hands exposed in the following conditions: Stage 1 baseline--total body garment inlet water temperature at 33 degrees C; Stage 2--left side inlet water temperature heated to 45 degrees C; right side cooled to 8 degrees C; Stage 3--left side inlet water temperature cooled to 8 degrees C, right side heated to 45 degrees C. RESULTS: Temperatures on each side of the body surface as well as ear canal temperature (Tec) showed statistically significant Stage x Side interactions, demonstrating responsiveness to the thermal manipulations. Right and left finger temperatures (Tfing) were not significantly different across stages; their dynamic across time was similar. Rectal temperature (Tre) was not reactive to prevailing cold on the body surface, and therefore not informative. Subjective perception of heat and cold on the left and right sides of the body was consistent with actual temperature manipulations. CONCLUSIONS: Tec and Tre estimates of internal temperature do not provide accurate data for evaluating overall thermal status in nonuniform thermal conditions on the body surface. The use of Tfing has significant potential in providing more accurate information on thermal status and as a feedback method for more precise thermal regulation of the astronaut within the EVA space suit.

Adult↗
PubMed1998

Proposed mechanism for stability of proteins to evolutionary mutations.

It is shown that the sequence-ordering tendencies induced by design into different fast-folding, thermally stable native structures interfere. This interference results in a type of quasiorthogonality between optimal native structures, which divides sequence space into fast-folding, thermally stable families surrounded by slow-folding, low stability shells. A concrete example of this effect is provided by using a simple alpha carbon type model in which a complete correspondence is established between sequence and structure. It is speculated that gaps can occur in the space of protein-like sequences separating the sequence families and resulting in a mechanism for stability and diversity of protein sequence information.

Evolution, Molecular↗
PubMed1987

Anirolac vs. naproxen for postpartum uterine pain.

Anirolac, a new nonsteroidal anti-inflammatory drug, was evaluated for relative efficacy, safety, and time course of analgesia. In a stratified, randomized, parallel, double-blind trial, 120 hospitalized women with moderate or severe postpartum uterine pain were treated with single oral doses of anirolac, 50 or 100 mg, naproxen sodium, 550 mg, or placebo. Using verbal scales, patients rated pain intensity, pain relief, and side effects at regular intervals for 6 hours. Highest summed analgesic ratings over placebo were induced by anirolac, 100 mg (P less than or equal to 0.001), and naproxen (P less than or equal to 0.001), followed by anirolac, 50 mg (P less than or equal to 0.005). At each assessment after the first hour, anirolac, 50 and 100 mg, and naproxen induced significantly stronger analgesia than did placebo. Statistically significantly more drowsiness was reported with all three active agents than with placebo. Our results suggest that, for postpartum uterine pain, analgesia with anirolac, 50 or 100 mg, is equivalent to that with naproxen, 550 mg.

Administration, Oral↗
PubMed1980

Consumer focus of a university drug and poison information center.

The consumer-oriented aspect of a university drug and poison information center is described. The University of Cincinnati Medical Center began its 24-hour consumer drug information telephone service in 1972. It is staffed by seven full-time employees, and pharmacists and pharmacy residents of nearby hospitals handle evening and weekend calls. All participating personnel are trained in structured programs. The $78,000 annual budget for the consumer drug information service is funded exclusively from external sources such as mental health agencies, foundations, and donations. Of 40,719 calls handled by the center in 1979, 83% were from the public. The total annual call volume has increased by 250% since 1972. In telephone follow-up of consumer calls, 73% of persons claimed they followed verbatim the advice given. Of calls during 1972, 1974, 1977, and 1979, 32.2% concerned drug abuse; 28.6%, identification of ingredients; and 10.9%, efficacy. Data from a three-month study in 1979 showed that the goal perceived by the information provider was to satisfy the curiosity of the caller 63.6% of the time (35.6% of the time immediate action was indicated). The authors believe that the center promotes appropriate use of physicians and pharmacists as sources of information for consumers.

Academic Medical Centers↗
PubMed1979

Abuse and pulmonary complications of injecting pentazocine and tripelennamine tablets.

A current practice among drug abusers in certain Midwestern and Eastern cities is the intravenous injection of aqueous mixtures prepared from tablets of pentazocine and tripelennamine. Patients present with acute hypoxic episodes and symptoms suggesting physical dependence to pentazocine. Two cases are presented illustrating acute respiratory distress with hypoxia. Available evidence indicates that the respiratory syndrome is produced by talc from the injected tablets. Respiratory support and short-term oxygen therapy have been effective in managing this syndrome. Approaches to the treatment of pentazocine dependence and the role of the antihistamine in potentiating the narcotic activity are also discussed. Physicians, drug abuse counselors, and others should be aware of the abuse potential and pulmonary damage which can result from the intravenous use of this drug combination.

Adult↗
PubMed1978

A comparison of four toxicology resources in respect to rates of retrieval and time required.

An evaluation was conducted fo four periodically updated poison control resources widely used by pediatricians, emergency room personnel, and poison information/control centers; i.e., Poisindex, ToxiFile, Clinical Toxicology of Commercial Products, and the National Clearinghouse for Poison Control Centers' cards. The frequency of finding entries for substances known to be involved in accidental pediatric ingestions, the extent of the content and management information, and the time required to obtain the information were determined for the four resources. Poisindex was more complete than the other resources. ToxiFile was more useful than the remaining two resources, although the latter should be useful in over 70% of accidental toxic ingestions by children.

Humans↗
PubMed1978

Popping and snorting volatile nitrites: a current fad for getting high.

In certain social circles a variety of volatile nitrites are being used extensively to expand creativity, stimulate music appreciation, promote a sense of abandon in dancing, and intensify sexual experience. Soon after amyl nitrite (the prototype of this group) became a prescription drug, legally produced substitutes appeared and were sold as room odorizers. Analyses of eight of these substitutes showed them to contain isomers of butyl or amyl alcohol and a corresponding nitrite. The authors describe the context of use of these products and their desired and adverse effects.

Amyl Nitrite↗
PubMedDate not supplied

Are high-dose toxic exposures always associated with reactive airways dysfunction syndrome (RADS)?

Bottling plant workers were evaluated for respiratory symptoms following an accidental exposure to a chlorine dioxide aerosol. Six exposed employees underwent medical and occupational histories, skin testing to common allergens, spirometry before and after use of bronchodilators, and methacholine challenge. The reported exposure to chlorine dioxide ranged from 30 min to 12 hr. Physical examinations were all normal. Four workers had positive prick skin tests to common aeroallergens. None of the workers demonstrated significant changes in forced expiratory volume in 1 sec following use of bronchodilators, and none experienced methacholine hyperresponsiveness. These cases suggest that the occurrence of reactive airways dysfunction syndrome is unpredictable and may not always occur in heavily exposed individuals.

Adult↗
PubMedDate not supplied

Injection drug users in the Midwest: an epidemiologic comparison of drug use patterns in four Ohio cities.

Variations in the drug use patterns of injection drug users (IDUs) can have important implications for public health efforts aimed at reducing drug abuse and the transmission of the human immunodeficiency virus. This article describes and compares the characteristics of IDUs living in four Ohio cities and compares African-American and White IDUs at a statewide level. Data from 2,001 IDUs who were recruited for the National AIDS Demonstration Research project between 1989 and 1991 in Columbus, Cleveland, Cincinnati, and Dayton were compared on a number of variables by city and by ethnicity using descriptive statistics and ANCOVA analysis. Significant differences among IDUs in the four cities exist for the use of alcohol, marijuana, cocaine, crack, heroin, speedball, other opioids, shooting gallery use, "safer" needle practices, treatment history, and self-help participation. Differences by ethnicity emerged on all variables except marijuana use, overall injection frequency, and incarceration experience. The results suggest that dramatic differences exist between African-American and White IDUs, and among IDUs in cities relatively close together, regardless of ethnicity. These findings should be considered when developing policy and programs for prevention and treatment activities targeting IDUs.

Adult↗