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Biomedical subjects

L Harter

Publications and source records attributed to L Harter.

14 recordsLinked to original sources
PubMed2001

Hazardous materials events: evaluation of transport to health care facility and evacuation decisions.

The study objective was to analyze hazardous materials event and victim factors associated with transportation of victims to a health care facility, and evacuation or shelter-in-place of nearby populations. A retrospective review was conducted on hazardous materials events in Washington State from 1993 to 1997. Bivariate and multiple logistic regression were used to identify risk factors for transportation, evacuation, and shelter-in-place. Over five years, 2,654 victims from 457 events were reported, with 1,859 (70%) transported to a health care facility. Evacuation occurred in 279 (61%) events and shelter-in-place in 14 (3%) events. After excluding 14 deaths, regression analysis indicated that victims with trauma (OR 5.87, 95% CI 1.41-24.5), thermal burns (6.90, 1.15-41.3), dizziness/other CNS symptoms (1.59, 1.00-2.54), and headache (1.54, 1.01-2.35) were most likely to be transported. Chemical releases inside buildings (2.09, 1.06-4.10, compared with transportation events), and involving 3-5 victims (2.86, 1.54-5.31, compared to 1 victim) or > or =6 victims (8.74, 4.01-19.0), were most likely to involve evacuation or shelter-in-place. Events involving sulfuric acid (0.15, 0.05-0.49) and sodium hydroxide (0.19, 0.04-0.94) were least likely to involve evacuation or shelter-in-place. Prehospital decisions to transport victims to a health care facility and evacuate or shelter-in-place nearby populations are associated with event and victim factors. Further research is needed to determine if these factors also predict need for medical care or removal from exposure, and to develop evidence-based prehospital care protocols for hazardous materials exposure victims.

Adolescent↗
PubMed2000

Hazardous materials events: an industrial comparison.

Identifying industries at high risk for hazardous materials releases can facilitate prevention and preparation for such events. A retrospective review by Standard Industrial Classification (SIC) codes was conducted on non-petroleum hazardous materials emergency events from 1993 to 1995 and collected by the Washington State Department of Health in a program supported by the Agency for Toxic Substances and Disease Registry. Annual US Census data were used to determine the number of facilities and employees by SIC code in the state of Washington. SIC codes with the most total events and events per 10,000 employees were ranked and characterized by type of releases. In 3 years, 1269 events were recorded, with 294 involving human victims. Industries with the highest average annual number of events per 10,000 employees were agricultural chemical manufacturing (142); petroleum refining (122); industrial and miscellaneous chemical manufacturing (56); electric light and power (54); and pulp, paper, and paperboard mills (39). Industries with high rates of hazardous materials emergency events should continue to develop methods of preventing these releases.

Emergencies↗
PubMed1999

Volume regulatory decrease in UMR-106.01 cells is mediated by specific alpha1 subunits of L-type calcium channels.

An early cellular response of osteoblasts to swelling is plasma membrane depolarization, accompanied by a transient increase in intracellular calcium ([Ca2+]i), which initiates regulatory volume decrease (RVD). The authors have previously demonstrated a hypotonically induced depolarization of the osteoblast plasma membrane, sufficient to open L-type Ca channels and mediate Ca2+ influx. Herein is described the initiation of RVD in UMR-106.01 cells, mediated by hypotonically induced [Ca2+]i transients resulting from the activation of specific isoforms of L-type Ca channels. The authors further demonstrate that substrate interaction determines which specific alpha1 Ca channel subunit isoform predominates and mediates Ca2+ entry and RVD. Swelling-induced [Ca2+]i transients, and RVD in cells grown on a type I collagen matrix, are inhibited by removal of Ca from extracellular solutions, dihydropyridines, and antisense oligodeoxynucleotides directed exclusively to the alpha1C isoform of the L-type Ca channel. Ca2+ transients and RVD in cells grown on untreated glass cover slips were inhibited by similar maneuvers, but only by antisense oligodeoxynucleotides directed to the alpha1S isoform of the L-type Ca channel. This represents the first molecular identification of the Ca channels that transduce the initiation signal for RVD by osteoblastic cells.

Animals↗
PubMed1989

The influence of electrical variables on analgesia produced by low current transcranial electrostimulation of rats.

Pulsed low current transcranial electrostimulation (TE) has been shown to induce analgesia in rats as measured by the wet tail flick test. This study investigates the effect of varying stimulus frequency, pulse width, charge balance and polarity, as well as the influence of electrode placement and time of day at which stimulus occurred. A biphasic, charge balanced waveform with a first phase duration of 2 msec, current 10 microA and repetition rate 10 Hz was found to induce maximum tail flick latency changes. The effects of morning or nighttime stimulation were statistically indistinguishable, as were the differences between monophasic and biphasic stimulation. Analgesia was maximized when a positive first phase was delivered into the right ears of the rats, but monolateral stimulation with both electrodes on either the left or the right ear produced no measurable effect. Examination of TE responses in sham and stimulated populations reveals normal response distributions with the stimulated group skewed toward a positive effect.

Analgesia↗
PubMed1987

Cerebrospinal fluid from morphine-dependent rats precipitates opiate abstinence syndrome.

Cerebrospinal fluid (CSF) was withdrawn from opiate-dependent rats following six hours of abstinence. It was infused into the third ventricle of opiate-dependent rats, precipitating immediate abstinence signs. The effect was similar to that of infusing the opiate antagonist naloxone, suggesting that opiate-dependent organisms may secrete an endogenous opiate antagonist substance. CSF withdrawn from non-dependent rats failed to precipitate an abstinence syndrome in morphine-dependent recipients. Conversely, CSF withdrawn from opiate-dependent rats following six hours of abstinence failed to precipitate an abstinence syndrome in non-dependent recipients. The active factor in the CSF is probably a peptide since it is filterable through a 10,000 MW filter and its activity is destroyed by three different proteolytic enzymes.

Animals↗
PubMed1986

A comparative study of hospital fetal death records and Washington State fetal death certificates.

Hospital fetal death records were compared with Washington State fetal death certificates to ascertain the completeness of reporting. Washington State law requires reporting of all fetal deaths of 20 or more weeks gestation. For 16 hospitals reporting 603 fetal deaths, an additional 49 fetal deaths were identified in the mother's charts. The study documents underreporting, especially in the gestational ages closet to the 20-week age limitation where 71 per cent of the 48 unreported cases were 20 to 27 weeks gestation.

Death Certificates↗
PubMed1985

A three-state study of waterborne disease surveillance techniques.

For a two-year period, the states of Colorado, Vermont and Washington tested the effectiveness of ten surveillance methods for identifying waterborne disease. Nine were active surveillance methods, soliciting illness reports; one was passive, relying on voluntary disease reporting. One waterborne disease outbreak was identified through use of the nine active methods, while 14 were reported through the passive surveillance method. The presence of coliform bacteria during routine water testing was not related to illness in the community.

Colorado↗
PubMed1984

Giardiasis in an infant and toddler swim class.

A Giardia infected Washington State child was found to participate in an infant and toddler swim class. A stool survey of 70 child participants revealed a 61 per cent prevalence of Giardia infection. Also, 39 per cent of 53 mothers and 28 per cent of 21 fathers were Giardia positive. None of the non-swimming playmates were positive. Thirty-five per cent of 23 children exposed only at a better maintained pool to which the classes had been moved four weeks prior to the survey were positive. No evidence of transmission to non-swim class pool users was found.

Adult↗
PubMed1982

Giardia prevalence among 1-to-3-year-old children in two Washington State counties.

A survey of intestinal parasites was conducted in two Washington counties. Giardia prevalence among 518 children surveyed was 7.1 per cent and was unrelated to the source of domestic drinking water (surface or well), day care center attendance, or parental occupation. Identified risk factors for Giardia infection include a history of drinking untreated surface water and having two or more siblings between the ages of 3 and 10 years. Of 47 family members of Giardia positive children, 10 (21.3 per cent) were Giardia positive.

Child↗
PubMedDate not supplied

Lung cancer among women residing close to an arsenic emitting copper smelter.

Lung cancer deaths occurring between 1935 and 1969 among women residing near an arsenic emitting smelter were examined. For three geographically defined exposure groups, the observed and expected number of lung cancer deaths were compared. In none of the exposure groups did the observed number of deaths exceed the expected. However, an index of exposure based on distance of residence from the smelter and duration of residence in the area was 27% higher for cases than for age-matched controls (p = .10). Adjusting for a latency of 20 yr, case exposures were 23% higher than for controls (p = .07). Dividing individuals into quintiles of exposure yielded odds ratios ranging from 1 to 1.6 (test of trend, p = .07).

Adult↗