Biomedical subjects
K Jones
Publications and source records attributed to K Jones.
The abuse of drugs.
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The independence and interdependence of cells in the amphibian embryo.
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Opiate withdrawal in the infant.
Large numbers of human infants are exposed in utero to illicit opiate drugs such as heroin and to prescribed opiates such as methadone. It is therefore important to understand the effects of acute and chronic exposure to drugs such as these on the immature organism. A necessary step in understanding the long-term effects of early drug exposure is to describe fully how the drug acts on neurobehavioral systems in the neonate. Because infants typically experience withdrawal from opiates, either in utero or shortly after parturition, a fuller understanding of the consequences of opiate withdrawal in the immature animal is an important but largely unexplored area of research. Although there has been some question as to whether infants undergo withdrawal, more recent experiments demonstrate that the rat neonate experiences clear behavioral changes during opiate abstinence, including the induction of "dysphoric" states on cessation of drug exposure. It is proposed that the infant organism undergoes withdrawal but that the signs and symptoms experienced differ from those suffered by the adult.
Psychiatric disorders and survival after lung transplantation.
The 30 patients who underwent lung transplantation between 1990 and 1996 were included in this study, and data were analyzed to find predictors of 1-year survival posttransplantation. All patients were followed throughout the posttransplantation period. Fifteen patients had a pretransplantation diagnosis of an anxiety and/or depressive disorders. Of the 30 patients transplanted, 19 survived 12 months or more, and 11 died less than 12 months posttransplantation. The > 12-month survival group had a mean age of 45.2 years at transplantation, compared with a mean age of 43.0 years in the < 12-month group (NS). The mean Psychosocial Assessment of Candidates for Transplant score and premorbid history of smoking did not differ between the groups. The > 12-month survival group had more psychiatric illness pretransplantation than the < 12-month survival group (56% vs. 27%, P < 0.05). The recipients with a psychiatric history (N = 15) were more likely to survive 1 year posttransplantation than the recipients without a psychiatric history (80% vs. 47%, P < 0.05) and were not significantly different from the recipients without a psychiatric history in terms of episodes of rejection, bronchiolitis obliterans, or noncompliance with treatment. Depression and anxiety are treatable disorders that occur frequently in patients with end-stage lung disease, and a premorbid history of either did not predict a worse outcome posttransplantation in this study of lung transplantation recipients.
Transplacental cocaine exposure. 2: Effects of cocaine dose and gestational timing.
We have utilized a mouse model of transplacental cocaine exposure to investigate the effects of cocaine dose and gestational timing in altering brain and body growth and postnatal behavior in exposed offspring. Pregnant dams were injected with cocaine HCl at 40 mg/kg/day (COC 40) or 20 mg/kg/day (COC 20), or 10 mg/kg/day (COC 10) SC from embryonic day (E) 8 to E17, or cocaine HCl at 40 mg/kg/day SC from E8 to E13 (COC Early) or from E13 to E17 (COC Late) divided in two daily doses. COC 40 and COC Late dams, as well as dams in nutritionally paired control groups (injected with saline vehicle and pair-fed with the COC dams: SPF 40, SPF 20, SPF 10), demonstrated less weight gain than SAL controls (injected with saline vehicle and allowed access to food ad lib). The surrogate fostered offspring of COC 40 and SPF 40 dams demonstrated brain and body growth retardation [on postnatal day (P) 1 and P9] when compared to pups born to SAL dams. Offspring of COC Late, SPF 20, and SPF 10 dams demonstrated brain and body growth retardation on P1 when compared to pups born to SAL dams. Pups from all groups were tested for first-order Pavlovian conditioning on P9, or for the ability to ignore redundant information in a blocking paradigm on P50. Only COC 40 mice (i.e., offspring born to COC 40 dams) were unable to acquire an aversion to an odor previously paired with shock on P9. When compared with SAL controls, COC 40 mice (and to a less significant extent SPF 40 mice) demonstrated a persistent behavioral deficit in the blocking paradigm on P50, which may reflect alterations in selective attention. Correlation analyses indicated that the dose and gestational timing of transplacental cocaine exposure, and varying degrees of malnutrition, had effects on blocking performance, with greater prenatal cocaine exposure and increased prenatal malnutrition resulting in more significant behavioral impairments. A path regression analysis demonstrated independent and significant effects of prenatal cocaine as well as prenatal malnutrition in contributing to impaired performance in the blocking paradigm. As suggested by the clinical literature, our preclinical data support a model whereby the dose and duration of prenatal cocaine exposure have direct effects on offspring brain and body growth and on behavioral performance.
Health hazards to timber and forestry workers from the Douglas fir tussock moth.
A heavy infestation of the tussock moth caterpillar (Orgyia pseudotsugata McDonnough) in forested areas of Oregon was associated with itching of the skin and eyes, nasal discharge, cough, and, at times, respiratory difficulty, Personal interviews and inspection of forty-one occupationally exposed persons were supplemented by a questionnaire administered to 428 individuals, composing three groups at various degrees of risk and a control group. There was a cause and effect relationship between the adverse symptoms and the exposure to tussock moth larvae. The specific etiologic agent was not identified, but it was felt that the secretion, hairs, or other substances in the larvae or cocoons of the moth acted as a potent allergenic substance and, for some persons, was also a primary skin irritant.
Migrant farm workers' access to pesticide protection and information: Cultivando Buenos Habitos campaign development.
Formative evaluation of south Georgian migrant farm workers' access to information and products to promote pesticide protection and understanding of cancer risk associated with pesticide exposure was conducted using field observation, in-depth interviews of Georgia's Migrant Health Program's outreach workers, and structured face-to-face surveys of migrant farm workers. The data indicated that fewer than one-third of the pesticide products reviewed contained messages about pesticide use and exposure risk for humans. Risk information on products appeared in English only. Few protective devices were available for purchase. Migrant farm workers were aware in a very general sense of health risks posed by pesticides, but they were specifically unaware of the reach of pesticides sprayed, as illustrated by their field behaviors. Findings also demonstrated the need to educate outreach workers about migrant farm workers' cancer risk, so that they may act as migrant farm workers' health advocates to reduce the adverse effects associated with pesticide exposure.
Development and validation of a competitive immunoassay for urinary S-phenylmercapturic acid and its application in benzene biological monitoring.
An immunoassay that quantifies urinary S-phenylmercapturic acid (PMA), a benzenespecific biomarker, has been developed and its potential usefulness as a screening tool for monitoring occupational exposure to benzene has been demonstrated. Analytical reliability has been confirmed by correlation of results with gas chromatography-mass spectrometry (GC/MS) data (R = 0.92). The assay has been configured as a competitive enzyme-linked immunosorbent assay (ELISA) to facilitate rapid throughput of samples. The ELISA has a working range of 40-1200 nmoll-1 urinary PMA and appears to be unaffected by the presence of structurally related urinary metabolites. Background levels of 0-1.9 mumol PMA/mol creatinine (mean 0.9 mumol mol-1, n = 32) were measured in nonsmoking control subjects. Recent exposures to benzene (8 h time-weighted averages-TWA), during diverse industrial processes, over the range 0-4.8 ppm were identified by application of the assay in biological monitoring programmes.
Development of a urinary biomarker for exposure to the organophosphate propetamphos: data from an oral and dermal human volunteer study.
Propetamphos is a member of the vinyl phosphate group of insecticides and is mainly used for sheep dipping. There have been no published metabolic studies on the effect of propetamphos in man to date, although the present authors have published the identification of a metabolite. The present paper presents data from a human volunteer study investigating the toxicokinetics of the organophosphorus pesticide propetamphos following oral and dermal exposure. Five volunteers ingested a propetamphos dose of 10 micrograms kg-1 (35 nmol kg-1) body weight. Following a washout of 4 weeks, a 100 mg (356 mumol) dermal dose of propetamphos was applied, occluded to 80 cm2 of the inner forearm, for 8 h to the same five volunteers. In a pilot study (several weeks before the main study), one volunteer also received an occluded dermal dose of 50 mg (178 mumol) propetamphos. Unabsorbed propetamphos on the skin was washed off after 8 h and collected. Blood and urine samples were collected over 30 and 54 h for the oral and dermal exposures respectively. Blood samples were analysed for plasma and erythrocyte cholinesterase. Urine samples were analysed for a urinary metabolite of propetamphos: methylethylphosphoramidothioate (MEPT). Following oral and dermal exposure, peak urinary MEPT levels occurred at 1 and 10-12 h respectively. The apparent urinary elimination half-lives of MEPT had means of 1.7 h (oral exposure) and 3.8 h (dermal exposure). Approximately 40% of the oral dose and 1% of the dermal dose were recovered as urinary MEPT or metabolites, which could be hydrolysed to MEPT. Approximately 90% of the dermal dose was recovered from the skin washings. Data from a volunteer showed that a doubling of the dermal dose resulted in approximately double the concentration of total MEPT. Alkaline hydrolysis of urine samples increased the level of MEPT detected after both oral and dermal doses. The increase was greater and statistically significant (p < 0.001, paired t-test) for the dermal dose. This increase in MEPT suggests the presence of other MEPT-containing metabolites or conjugates. The difference in the increase between oral and dermal doses raises the question of a difference in metabolism between the two routes. No individual showed a significant depression compared with their pre-exposure levels of erythrocyte acetyl cholinesterase or plasma cholinesterase activity for either dosing route. However, on a group basis, there was a statistically significant mean depression in plasma cholinesterase activity at 8 and 24 h for oral exposure, with a maximum mean depression of 7% from pre-exposure levels at 8 h. Hydrolysis of urine samples had the effect of reducing the interindividual coefficient of variation (CV) for total excretion of MEPT following both oral (CV reduced from 36 to 8%) and dermal (CV reduced from 40 to 17%) exposure. The ability to detect and follow the elimination of low doses of propetamphos by measurement of 'total' (after hydrolysis) urinary MEPT suggests it is a suitable biomarker of propetamphos exposure. The comparatively short elimination half-lives suggest a strategy for biological monitoring of occupational exposure based on samples collected at the end of the shift.
A human exposure study to investigate biological monitoring methods for 2-butoxyethanol.
2-Butoxyethanol is a glycol ether widely used in printing inks, varnishes and cleaning fluids. As skin absorption can be significant, biological monitoring is useful in monitoring worker exposure. A number of analytes and matrices have been used previously, including 2-butoxyethanol in blood and free and total 2-butoxyacetic acid in urine. Using a combination of a volunteer study and samples from exposed workers, we compared the applicability of some of the biological monitoring markers available. We conclude that 2-butoxyethanol in blood is not a suitable marker for biological monitoring due to sampling problems. In view of the low-level exposures reported in occupational surveys, 2-butoxyethanol in breath is also unsuitable because of a lack of sensitivity. Measuring 2-butoxyacetic acid in blood is possible, although non-invasive urine samples are preferred. Free 2-butoxyacetic acid in urine has previously been widely used; however, we found that the extent of conjugation of 2-butoxyacetic acid in urine varied from 0 to 100% both within and between individuals and is not related to time, concentration or urine pH. Data from 48 exposed workers suggested that an estimated 57% (95% confidence interval 44-70%) of the total 2-butoxyacetic acid is excreted in the conjugated form, and that conjugation may be activated above a certain exposure level. Using total 2-butoxyacetic acid significantly reduced inter-individual variation. Elimination half-lives for free and total 2-butoxyacetic acid were similar ( approximately 6 h) and there was no delay in excretion of the conjugated metabolite (peak excretion for both free and total was between 6 and 12 h after the end of exposure). In conclusion, we propose that total butoxyacetic acid (after acid hydrolysis) in urine is the biomarker of choice for monitoring exposure to 2-butoxyethanol. Urine samples should be collected post-shift towards the end of the working week.
The effect of donor cell serum starvation and oocyte activation compounds on the development of somatic cell cloned embryos.
Two experiments, one comparing nuclear transfer (NT) embryo activation compounds, the other donor cell treatments, were conducted with a goal of identifying factors that improve the in vitro development of cloned bovine embryos. In experiment 1, 539 NT embryos were produced by combining serum starved bovine fetal fibroblasts with enucleated in vitro matured oocytes, activated with ionomycin, then randomly allocated to be incubated for 4 hours in either Butyrolactone-I (BL-I) or 6-dimethylaminopurine (DMAP). There was no significant difference in development to blastocyst or compact morula of fused embryos at Day 6.5 between BL-I and DMAP activated embryos (22.4% vs. 20.2%; p = 0.18). Karyotyping of 20 blastocysts and compact morula from each group determined that 65% of BL1 and 63% of DMAP embryos were diploid with the remainder mixoploid (2n + 4n). In Experiment 2, the development of 389 NT embryos reconstructed from either serum starved or serum fed fetal fibroblasts was assessed. More Day 7 blastocysts and compact morula developed in the serum starved group (34.5% vs. 18.8%; p = 0.008). To verify the viability of BL-I activated embryos, 10 blastocytes from experiment 2 were transferred into 4 recipient cows. Two morphologically normal fetuses, genetically identical to the original fetal cell line, were surgically recovered at day 45 of gestation. In summary, serum starvation of bovine fetal fibroblasts prior to NT significantly improved development to blastocyst. Additionally, we have shown that BL-I is a novel alternative compound for use in combination with ionomycin to activate NT embryos.
Cognitive and psychomotor development of infants with orofacial clefts.
OBJECTIVE: To compare at ages 3, 12, and 24 months the cognitive and psychomotor development of 29 infants with cleft lip and palate (CLP), 28 infants with cleft palate only (CPO), and a demographically matched comparison (COMP) group of 69 infants; to examine predictors of cognitive status at age 24 months in the cleft group. METHODS: Infants were administered the Bayley Scales of Infant Development (BSID), mother-infant interactions were observed, and medical records were reviewed. RESULTS: CLP and CPO groups scored lower than the COMP group on the BSID, but did not differ from one another. Cleft group infants scored lower than COMP group infants on BSID items assessing nonverbal and expressive language skills. Quality of maternal interaction predicted the 2-year Mental Development Index (MDI) scores of infants with clefts. CONCLUSIONS: Infants with clefts show relative deficits in cognitive and psychomotor development. Cognitive deficits are apparent in nonverbal as well as verbal areas of performance.
A cost-benefit analysis of shared governance.
Shared governance is one of several strategies promoted by and to nurse executives as critical to retention of professional nurses and important in maintaining quality of care. Thus far, few studies have examined the various financial aspects of this type of decision-making structure. This article identifies a framework for cost analysis and reports the cost-benefit relationship of implementing a shared governance model over a 5-year period.
Two-year-olds will name artifacts by their functions.
Do young children take functional information into account in naming artifacts? In three studies of lexical categorization, 112 children 2 years of age learned new names for novel artifacts with novel functions and then extended the names to new objects. The objects were designed to have functions that were causally related in simple and compelling ways to perceptible aspects of their physical structure. Despite only minimal opportunity to familiarize themselves with the objects, children generalized the names in accordance with the objects' functions. This result obtained even when children had to discover the functions of the named objects on their own (Experiment 2) and when all the test objects had some discernible function (Experiment 3). Two-year-olds name by function when they can make sense of the relation between the appearances and the functions of artifacts.
Are blood glucose reagent strips reliable in renal failure?
In vitro studies have suggested that a low packed cell volume may cause reagent strips to overestimate blood glucose concentration. The reliability of such strips has therefore been investigated in diabetic patients with end-stage renal failure, all of whom had low haematocrits (24 +2- 4 (4/- SD) %). Three brands of strips were evaluated and their results were compared with laboratory whole blood glucose concentrations determined on the same samples. All over-read compared with the laboratory (BM Glycemie 1-44 strips 118 +/- 1%, Glucostix 132 +/- 2%, ExacTech strips 163 +/- 4%) and the percentage overread was negatively correlated with the haematocrit for each strip (all p less than 0.001).
Computer systems in labor and delivery units. Critical issues.
Although most hospitals use computer systems in other areas, many nurses have had limited hands-on experience with computers. The issues to address when a bedside computer system is selected and introduced into a labor and delivery unit are presented.
Murine embryonal carcinoma cells express class I MHC-like antigens.
Previous work has concluded that murine embryonal carcinoma (EC) cells, the oncogenic stem cells of teratocarcinomas, do not express class-I, H-2K or D/L gene encoded products. Experiments using cell-mediated lysis, serological and molecular biological approaches show that EC cells do express some major histocompatibility complex (MHC) class I or class I-like molecules.