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Biomedical subjects

L Parker

Publications and source records attributed to L Parker.

At least 163 records · Page 9Linked to original sources
PubMed1991

Parental occupations of children with leukaemia in west Cumbria, north Humberside, and Gateshead.

OBJECTIVE: To determine whether parental occupations and chemical and other specific exposures are risk factors for childhood leukaemia. DESIGN: Case-control study. Information on parents was obtained by home interview. SETTING: Three areas in north England: Copeland and South Lakeland (west Cumbria); Kingston upon Hull, Beverley, East Yorkshire, and Holderness (north Humberside), and Gateshead. SUBJECTS: 109 children aged 0-14 born and diagnosed as having leukaemia or non-Hodgkin's lymphoma in study areas during 1974-88. Two controls matched for sex and date and district of birth were obtained for each child. MAIN OUTCOME MEASURES: Occupations of parents and specific exposure of parents before the children's conception, during gestation, and after birth. Other adults living with the children were included in the postnatal analysis. RESULTS: Few risk factors were identified for mothers, although preconceptional association with the food industry was significantly increased in case mothers (odds ratio 2.56; 95% confidence interval 1.32 to 5.00). Significant associations were found between childhood leukaemia and reported preconceptional exposure of fathers to wood dust (2.73, 1.44 to 5.16), radiation (3.23, 1.36 to 7.72), and benzene (5.81, 1.67 to 26.44); ionising radiation alone gave an odds ratio of 2.35 (0.92 to 6.22). Raised odds ratios were found for paternal exposure during gestation, but no independent postnatal effect was evident. CONCLUSION: These results should be interpreted cautiously because of the small numbers, overlap with another study, and multiple exposure of some parents. It is important to distinguish periods of parental exposures; identified risk factors were almost exclusively restricted to the time before the child's birth.

Adolescent↗
PubMed1991

Rough but ready.

Explore the source record for details and available documents.

Data Interpretation, Statistical↗
PubMed1991

Prompt engraftment using autologous peripheral blood stem cells for double autologous bone marrow rescue.

A patient with Hodgkin's Disease, stage IIIA, was treated for recurrent disease with autologous peripheral blood stem cells after ablative chemotherapy. Bone marrow rescue occurred promptly and his disease was significantly reduced. Ablative chemotherapy was administered again and a second bone marrow rescue with peripheral blood stem cells was successful. Sequential peripheral blood stem cell bone marrow rescue, following high dose chemotherapy, may provide an alternative approach in selected patients.

Adult↗
PubMed1991

Effects of pimozide on the hedonic properties of sucrose: analysis by the taste reactivity test.

The ability of the neuroleptic agent, pimozide, to modify sucrose palatability was assessed using three 10-min taste reactivity test sessions. Pimozide was found to suppress the ingestive response of tongue protrusions, but enhance the mildly ingestive/neutral response of mouth movements elicited by an intraoral infusion of sucrose solution. Since the pattern of taste reactivity responding shifted from highly ingestive to mildly ingestive/neutral, our results suggest that pimozide pretreatment reduces the palatability of sucrose solution. The temporal pattern of the modification of these taste reactivity responses was predicted by the Anhedonia Hypothesis.

Animals↗
PubMed1991

Genotoxicity of 2-amino-6-N-hydroxyadenine (AHA) to mouse lymphoma and CHO cells.

2-Amino-6-N-hydroxyadenine (AHA) treated L5178Y/TK (+/-)-3.7.2C mouse lymphoma cells were evaluated for mutations at the tk, hgprt, and Na+/K+ ATPase loci, as well as for gross chromosome aberrations and induction of micronuclei. In addition, AHA was evaluated for its ability to induce HGPRT mutants in CHO cells. AHA was found to induce mutations at all evaluated loci and in both cell types. The TK mutants were primarily large colonies although a few small colonies were also induced, particularly at the higher concentrations. Preliminary cytogenetic analysis of AHA-treated mouse lymphoma cells indicated that some gross aberrations but not micronuclei were induced. The 20 small-colony TK mutants evaluated by banded karyotype indicate that only a small fraction (2 of 20) showed chromosome 11 abnormalities. From these studies, it appears that AHA may be one of a very few chemicals that is capable of inducing multi-locus point mutations, with only slight clastogenic activity. Particularly at the higher concentrations, some of the mutants may contain multi-locus point mutations that result in slow growth.

Adenine↗
PubMed1991

Analysis of the genotoxicity of anthraquinone dyes in the mouse lymphoma assay.

Despite their widespread use and potential for significant human exposure, genotoxicity data on anthraquinones and other dyes are limited. In this study, 16 anthraquinones and one azo dye (Solvent Red 1) were selected for testing using the thymidine kinase (tk) locus and micronucleus (MN) analysis in L5178Y/TK(+/-)-3.7.2C mouse lymphoma cells. Six of the dyes were from the same lot used in the NTP rodent bioassay. The dyes used were all production lots and thus varied in their purity. Disperse Blue 7, 2-aminoanthraquinone, 1-amino-2-methylanthraquinone, Disperse Blue 3 and Disperse Red 11 were genotoxic (inducing 1814 mutants/10(6) survivors, 369 MN/1000 cells at 13% survival; 397 mutants/10(6) survivors, 196 MN/1000 cells at 21% survival; 178 mutants/10(6) survivors, 119 MN/1000 cells at 51% survival; 264 mutants/10(6) survivors, 109 MN/1000 cells at 15% survival, respectively). Reactive Blue 19 was weakly mutagenic (inducing 144 mutants/10(6) survivors, but only 8 MN/1000 cells at 13% survival). Vat Yellow 4 and Solvent Red 1, with exogenous activation, were also mutagenic (inducing 300 mutants/10(6) survivors, 18 MN/1000 cells at 57% survival, and 100 mutants/10(6) survivors and 16 MN/1000 cells at 22% survival, respectively). With activation 1-nitro-2-methylanthraquinone was judged to give an equivocal mutagenicity response. The maximum test concentration was limited for some compounds by their solubility. Those chemicals that did not induce mutation or cytotoxicity at the limits of solubility were classified separately. Compounds which were not evaluated without exogenous activation because of insolubility but were evaluated with activation include 1-nitro-2-methylanthraquinone, Solvent Red 1 and Vat Yellow 4. Compounds which were not evaluated either with or without S9 activation because of their insolubility in the culture medium include 1-amino-2,4-dibromoanthraquinone, D&C Green, Disperse Blue 1, Disperse Red 60, Vat Blue 4, Vat Blue 20, Vat Brown 1 and Vat Brown 3.

Animals↗
PubMed1991

Comparison of mutagenicity results for nine compounds evaluated at the hgprt locus in the standard and suspension CHO assays.

The Chinese hamster ovary (CHO) assay, which measures newly induced mutations at the hypoxanthine-guanine phosphoribosyltransferase (hgprt) locus, has been widely used for mutagenesis testing. The insensitivity of the standard assay to some genotoxic agents has been speculated to be due to the relatively small number of cells used in the assay. In the present study, we have compared the standard monolayer assay with a suspension adapted CHO assay that uses cell numbers comparable to that of the L5178Y mouse lymphoma assay. Nine compounds, ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), 2-methoxy-6-chloro-9-[3-(ethyl-2-chloroethyl)-aminopropylamino]-acridine 2HCl (ICR 170), methyl acrylate, ethyl acrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, 2-ethylhexyl acrylate and dicyclopentenyloxyethyl methacrylate were evaluated in the monolayer and suspension assays. Both assays gave the same overall qualitative results for the test compounds. There were some quantitative differences in the mutant frequency for the three compounds found to be mutagenic (EMS, MMS and ICR 170). The acrylates (many of which appear to exert their genotoxic effect through a clastogenic mechanism) were negative in both test systems. The use of the suspension assay did not improve the ability of the hgprt locus to detect the genotoxicity of the acrylates. Thus, increasing the number of cells does not improve the ability of the CHO/HGPRT assay to detect compounds that act primarily by a clastogenic mechanism.

Acrylates↗
PubMed1991

Dementia in institutionalized elderly: relation to sleep apnea.

Sleep apnea is characterized by transient hypoxemias which are thought to affect mental functioning. Accordingly, speculation and research have focussed on relationships between sleep apnea and dementia. We studied 235 nursing home (ie institutionalized) patients (152 women with a median age of 83.5; 83 men with a median age of 79.7) with portable sleep recording equipment. The Mattis Dementia Rating Scale and the Geriatric Depression Scale were given to each. Seventy percent of the patients had five or more respiratory disturbances per hour of sleep and 96 percent showed some dementia. Sleep apnea was significantly correlated with all subscales on the dementia rating scale. There were trivial differences in dementia ratings between those with mild-moderate apnea and those with no apnea. There were significant differences, however, between the latter two groups and those with severe apnea. In particular, items reflecting attention, initiation and perseveration, conceptualization, and memory tasks on the DRS distinguished between those with and without severe sleep apnea. Among those patients with no depression, all patients with severe sleep apnea were also severely demented. Our data suggest that there is a strong relationship between dementia and sleep apnea when the sleep apnea and dementia are severe. Although causality cannot be inferred from associations, our hypothesis for study is that sleep apnea causes deficits in brain function, possibly due to global effects rather than any particular cortical or subcortical structure.

Aged↗
PubMed1991

Discharge planning and follow-up care: the asphyxiated infant.

Discharge planning and follow-up care of the asphyxiated infant is a complex process. Models of discharge planning, team member responsibilities, and teaching responsibilities are components of hospital discharge plans. Special care needs of these infants may include vision, hearing, immunizations, seizures, medications, and feeding. Families and health care professionals need to be familiar with programs providing financial resources for care of the infant such as private insurance, prepaid health care, Medicaid, Medical Needy program, Children with Special Health Care Needs (CSHCN), federal legislation mandating education and services for high-risk infants (PL 99-142 and PL 99-457) and intervention programs. Families returning to Newborn Follow-up programs become acquainted with a variety of professionals and types of neonatal and infant assessments. Providing teaching materials and information regarding special health problems, services and outcome, as it becomes known, is the responsibility of the extended health care team of nurses, physicians, home health services, psychologists, and therapists.

Aftercare↗
PubMed1991

Airborne pollen and fungal spore sampling on the central California coast: the San Luis Obispo pollen project.

A semiarid coastal location in San Luis Obispo, California was surveyed for 3 years (1986-1988) using a Rotorod sampler. Significant year-to-year variations in predominant pollen occurred, and abundant levels of fungal spores were observed. Coincidently, a large wildlands fire that may have affected pollen levels occurred in the region shortly before sampling began. The entire survey period took place during a drought.

Air Pollutants↗