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Biomedical subjects

J J Ryan

Publications and source records attributed to J J Ryan.

252 records · Page 14Linked to original sources
PubMedDate not supplied

Analgesic efficacy of amfenac, aspirin and placebo after extraction of impacted teeth.

Amfenac, an arylacetic acid derivative, is a new investigational, nonsteroidal antiinflammatory agent that has exhibited analgesic properties superior to those of phenylbutazone in animals. This double-blind, randomized, parallel study was an early clinical trial to evaluate the analgesic efficacy of one oral dose of amfenac 100 mg compared to aspirin 600 mg and placebo in 120 subjects with moderate to severe pain after extraction of impacted molar teeth. Self-evaluated subjective pain intensity and relief reports for 4 hours were used as indexes of response. Analgesic effects of amfenac were significantly superior to those of placebo (p less than 0.001) and aspirin (p less than 0.05) by most measurements. Aspirin 600 mg was superior to placebo based on total pain relief and global scores (p less than 0.05). Compared with aspirin 600 mg, amfenac 100 mg provided greater and faster analgesia, lasting at least for 4 hours. Ordinal pain intensity scores correlated well with the visual pain analog scale. Seven (17.5%) patients taking amfenac compared to 5 (12.5%) taking placebo reported minor adverse effects).

Adult↗
PubMedDate not supplied

Diagnostic and prognostic utility of flow cytometric DNA measurements in follicular thyroid tumors.

Distinguishing cellular follicular adenomas (FA) from minimally invasive follicular carcinomas (FC) continues to plague even experienced thyroid pathologists. DNA ploidy analysis has been promoted as a means of making this differentiation; however, the finding of DNA aneuploidy in FA has caused concern that they may demonstrate potential for malignant behavior or should even be reclassified as low-grade noninvasive cancers. In histologically-proven FC, nuclear DNA content has been claimed to have predictive power equivalent to that of all other prognostic factors combined. The aims of the present study, therefore, were to define the DNA ploidy characteristics of FA and FC, to assess the diagnostic potential of cell-cycle parameters, and, in FC, to investigate the prognostic role of such measurements. We measured DNA content of 124 tumors (60 FA, 64 FC). DNA pattern was normal (diploid) in 75% of FA and 45% of FC, tetraploid/polyploid (T/P) in 13% of FA and 25% of FC, and aneuploid in 12% of FA and 30% of FC. FC was histologically verified in 39% of DNA normal, 67% of T/P, and 73% of aneuploid tumors. DNA index, S-phase, G2M, and S-phase plus G2M were analyzed and were not helpful in differentiating between FA and FC. No patient with FA developed tumor recurrence. In FC (excluding the Hürthle cell variant), no significant differences were found among the 3 DNA ploidy groups with respect to either cancer death or tumor recurrence; however, combining the Hürthle cell variant of follicular carcinomas with pure follicular carcinomas, the presence of distant metastases, DNA aneuploidy, and patient age were the only independently significant prognostic variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMedDate not supplied

Hürthle cell (oxyphilic) papillary thyroid carcinoma: a variant with more aggressive biologic behavior.

The latest World Health Organization International Classification defines papillary thyroid carcinoma by its "follicular cell differentiation...as well as characteristic nuclear changes". However the oxyphilic (Hürthle cell) papillary carcinoma have nuclei which generally resemble the nuclei seen in oxyphilic follicular carcinomas, and such oxyphilic papillary tumors may behave more aggressively than typical papillary cancers. To further characterize these rare tumors, we identified during a 32-year period 22 patients with oxyphilic papillary cancer and compared them with 1,084 patients with typical papillary cancers and 57 patients with oxyphilic follicular cancers treated by the Mayo surgical group during the same time period. Although typical papillary and oxyphilic papillary cancers were comparable with regards to patient age, tumor size and extent, TNM stage, and prognostic score (AGES), there were significant differences. Compared to typical papillary tumors, oxyphilic papillary cancers had fewer neck nodal metastases at primary diagnosis (5% vs 40%, p less than 0.0001), were more often DNA non-diploid (71% vs 21%, p less than 0.001), and after 10 postoperative years had higher rates of both tumor recurrence (28% vs 11%, p less than 0.0001) and cause-specific mortality (1.7% vs 4%, p less than 0.0005). In these four important respects the oxyphilic papillary cancers more resembled the oxyphilic follicular cancers. For oxyphilic follicular cancers, the frequency of initial neck nodal metastases was 7% (cf 5%); 83% of the oxyphilic follicular tumors were non-diploid (cf 71%), and at 10 years postoperatively the tumor recurrence and cause-specific mortality rates were 28% and 18%, insignificantly different from 28% and 17% seen with the oxyphilic papillary cancers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Elevated dioxin blood levels in Russian chemical workers and their children following maternal exposure.

Elevated dioxin levels in children of female workers with elevated dioxin body burden following workplace exposure has not been previously reported. We previously reported elevation of polychlorinated dibenzo-p-dioxins, particularly 2,3,7,8-TCDD, in Russia male and female chemical production workers' blood. Exposure is thought to have occurred in the early 1960s and blood was drawn in 1991. Among those with elevated dioxin levels were women with grown children. Since dioxins can be transferred transplacentally and by nursing, it was decided to see if a relationship existed between blood dioxin levels in mothers and their children. Individual samples were obtained from factory office workers, production workers and their now adult offspring. A pooled blood sample (n = 100) from adult Ufa residents was obtained for comparison. Samples were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (CoPCBs). Office workers, production workers and workers' children 2,3,7,8-TCDD (TCDD) blood levels ranged from 11 to 273 parts per trillion (ppt) on a lipid basis, while the pooled blood sample (n = 100) from adult Ufa residents had a TCDD level of 12 ppt. Elevated TCDD was detected in all adult children of female production workers tested while two adult children of a male production worker had dioxin levels similar to the general population of Ufa. All children of workers had been nursed by their mothers for the first year of life and none have worked at a chemical plant. The data suggest that relatively large amounts of TCDD were transferred from mother to child approximately 18 to 28 years prior to blood collection. A sample of 2,4,-D amine salt produced at this factory was also analyzed to determine if its dioxin congeners might be contributing to dioxin contamination. 2,3,7,8-TCDD was not detected in the 2,4-D (detection limit of 0.02 ppb), although other dioxins were present, including some with 2,3,7,8- chlorine substitution.

Adult↗
PubMedDate not supplied

Lipid extraction from blood and biological samples and concentrations of dioxin-like compounds.

The extraction of lipid from human blood and other biological materials in the determination of dioxin-like and organochlorine compounds has been studies using different amounts of extracting solvent. When large volumes of ethanol-hexane are used to extract small blood samples, the total lipid extracted is incomplete as the polar phospholipids do not partition into the organic phase. This failure to extract all the blood lipid results in an inaccurately high concentration expressed on a lipid basis and, by corollary, a high biased body burden. This solvent dependence of lipid extraction does not appear to be a problem for most other biological and food samples since over 90% of the lipid is in the form of readily extractable neutral glycerides.

Adipose Tissue↗
PubMedDate not supplied

PCBs and dioxin-like compounds in plasma of adult Inuit living in Nunavik (Arctic Quebec).

Inuit people residing in the Arctic are unusually exposed to organochlorines through their traditional diet which includes large quantities of sea mammal fat. Recently, 499 Inuit adults from Nunavik (Arctic Quebec) participated in a large health survey and donated a blood sample for organochlorine and heavy metal analysis. Twenty pooled plasma samples were formed, each made of individual samples from the same age group, sex, and region of residence, to allow for dioxin-like compound determination. The mean total concentration of PCBs and dioxin-like compounds (the latter expressed in 2,3,7,8-TCDD toxic equivalents) were respectively 4.1 mg/kg lipids and 184.2 ng/kg lipids, compared to 0.13 mg/kg lipids and 26.1 ng/kg lipids for three control pooled plasma samples from Southern Quebec. Total PCBs and dioxin-like compound concentrations were strongly correlated (r = 0.98; p < 0.0001), increased with age and were greater in men than in women. Although the body burdens of PCBs and dioxin-like compounds are close to those which induced adverse health effects in laboratory animals, dietary benefits from the sea-food based diet still outweigh the hypothetical health risks.

Adult↗
PubMedDate not supplied

Decrease in levels and body burden of dioxins, dibenzofurans, PCBS, DDE, and HCB in blood and milk in a mother nursing twins over a thirty-eight month period.

This paper presents measured dioxin, dibenzofuran, PCB, DDE and HCB blood and milk levels and estimated body burdens in a mother who nursed twins for thirty-eight months. A total of thirteen milk samples and three blood samples were collected and analyzed. Measured PCDD and PCDF levels in milk decreased from 309 and 21 ng/kg (ppt) to 173 and 9 ng/kg, respectively, between March 1993 and September 1995. Based on the decrease in breast milk dioxin levels, we estimate that the nursing mother reduced her dioxin body burden from 310 to 96 ng dioxin toxic equivalents (TEQs), or approximately 69%. In two and one half years the level of HCB in the mother's milk decreased from 10.7 to less than 1.8 ng/g (ppb), the level of DDE decreased from 246 to 46 ng/g and the total level of non-coplanar PCBs decreased from 285 to 63 ng/g, on a lipid basis. We estimate that the twin's consumption of dioxins, dibenzofurans, and coplanar PCBs from breast feeding was approximately 115 ng TEQ per twin.

Adult↗
PubMedDate not supplied

Correlations among human plasma levels of dioxin-like compounds and polychlorinated biphenyls (PCBs) and implications for epidemiologic studies.

In studies of the potential health effects of background-level exposure to organochlorine compounds (e.g., polychlorinated biphenyls, polychlorinated dibenzodioxins, and polychlorinated dibenzofurans), investigators have often measured either polychlorinated biphenyls or polychlorinated dibenzodioxins/polychlorinated dibenzofuransbut not both. We measured polychlorinated biphenyls (including specific non-, mono-, and di-ortho congeners) and specific polychlorinated dibenzodioxins/dibenzofurans among 63 Canadian blood donors. Levels of these compounds were, in general, fairly correlated. For example, Pearson's correlation coefficient between log total polychlorinated biphenyl and log total polychlorinated dibenzodioxins was .52. These results suggest that in epidemiologic studies of health effects of background-level exposures to these compounds, the quantitative dose-response relation observed for a given compound (or class of compounds acting through a similar mechanism) may easily be miscalibrated or confounded.

Adolescent↗
PubMedDate not supplied

Dioxin-like compounds in fishing people from the Lower North Shore of the St. Lawrence River, Quebec, Canada.

In this study, investigators assessed exposure to dioxin-like compounds in a fishing population that inhabits small coastal communities along the Lower North Shore of the St. Lawrence River, Quebec. This population relies heavily on wildlife foods for sustenance. Investigators analyzed chemically the most popular marine foods (i.e., fish, crustaceans, sea mammals, and sea-bird eggs), and they also obtained 25 human plasma samples from individuals in two villages along the river. The mean level of total polychlorinated biphenyls in this population was approximately twice that found in the entire fishing cohort. Plasma levels of dioxin-like compounds, expressed as tetrachlorodibenzodioxin toxic equivalents, were approximately eight times higher than levels in urban residents. Most of the increase in tetrachlorodibenzodioxin toxic equivalents in the selected fish eaters resulted primarily from an elevation in polychlorinated biphenyls. Concentrations of dioxin-like compounds from the Lower North Shore were low in fish and seals, but concentrations were elevated in the eggs of sea birds. Given that there was also a significant statistical correlation in the entire population between human plasma levels and consumption of birds' eggs-and not other traditional foods-much of the increased human dose appeared to originate from this one food source. Because there appear to be increased, but uncertain, health risks from this elevated body burden, investigators advised the residents of the area to avoid consumption of wild birds' eggs (i.e., a food source of minor nutritional importance).

Adult↗
PubMedDate not supplied

Chlorinated compounds in tissues of chickens raised on pentachlorophenol-contaminated litter.

Broiler chickens were raised on commercial wood shavings containing 134 p.p.m. pentachlorophenol and on control litter consisting of corn-cob chips. Initial analysis of the wood-shaving litter showed the presence of hepta-, octa- and nonachlorinated diphenyl ethers, octa- and nonachlorinated 2-phenoxyphenols, and hepta- and octachlorinated dibenzodioxins. Analysis of liver, fat, and muscle tissue after nine weeks indicated the assimilation of these compounds with pentachlorophenol being present in the highest concentration. Chlorinated diphenyl ethers were detectable only in fat, while octa- and nonachlorinated 2-phenoxyphenols were found in all three tissues examined. While liver and fat contained hepta- and octachlorinated dibenzodioxins, no hexachlorinated congener was detected nor were significant amounts of dioxin found in muscle tissue. Although gross pathological examination of the birds did not indicate abnormalities, a mixed type of hepatic enzyme induction was observed in those birds raised on wood shavings.

Adipose Tissue↗
PubMedDate not supplied

Industrial chemical contamination of foods.

The chemical contamination of foods via industrial activity is varied and widespread with regard to both chemical and occurrence. Such contamination can arise by accident, by intent from regular ongoing industrial activity, and even from subsequent use of manufactured products themselves. The key factors in assessing whether a problem exists within a particular country are recognition and awareness that a problem can exist and the capability to define the extent and severity of the problem. Both factors are heavily dependent on the availability of well-equipped food control laboratories staffed by dedicated and competent personnel. In some situations the analytical techniques required are 'state of the art' involving sophisticated and expensive separations and determinations with extensive quality control procedures. In others, the techniques are much less complicated. In both, however, the production of valid data is paramount. To illustrate some of these differences in approach, details of ongoing Canadian programmes on polychlorinated dibenzo-dioxins and -furans in effluents from pulp and paper mills and on the migration of chemicals from packaging materials are presented.

Acrylonitrile↗
PubMedDate not supplied

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in human milk samples collected across Canada in 1986-87.

Monitoring of human milk samples for the presence of chemical contaminants has been carried out in Canada for several decades. In 1986-87 over 400 donations of human milk were collected nationwide and 100 of these, selected by province according to population, were analysed for the PCDDs/PCDFs. The results show the presence of about eleven different analytes all with 2,3,7,8-substitution with the PCDDs at higher and more variable concentrations than the PCDFs. On a 2,3,7,8-TCDD toxic equivalents (TEQ) basis, the mean value for the country is about 15 ng per kg milk fat. This TEQ value is similar to that from many other industrialized nations and about 50% lower than certain European states. Little or no variation was apparent in the milk content among the various Canadian provinces probably reflecting the uniformity of the general food supply across the country. Limited data over a period of five years suggest the average level of these compounds in human milk may be decreasing.

Benzofurans↗
PubMedDate not supplied

Trauma symptoms in substance abusers with and without histories of childhood abuse.

This study was designed to provide a prevalence rate of childhood abuse in patients being treated for alcohol and other drug problems, and to compare the extent of trauma symptoms that were present in substance abusers with and without childhood histories of physical, sexual, and emotional abuse. One hundred male veterans completed a standard test battery that included the Trauma Symptom Checklist and the Dissociative Experiences Scale. Clinical information pertaining to history of childhood abuse was obtained from the subjects' medical charts. Results demonstrated that 34% of the sample reported a history of childhood abuse. Although this group did achieve higher mean scores on all the scales, in comparison to the nonabused group, statistical significance was absent. Implications of these findings are discussed and future research is suggested.

Anxiety Disorders↗
PubMedDate not supplied

Toxicological response and its reversibility in rats fed Lake Ontario or Pacific coho salmon for 13 weeks.

Lake Ontario coho salmon were known to contain a mixture of chemical contaminants. A previous study demonstrated that rats fed the Lake Ontario fish-supplemented diet for 28 days exhibited mild biochemical and histological changes. The purpose of the present study was to determine the effects due to a longer term of exposure and the reversibility of these effects. Growth rate and food consumption were not affected by feeding the animals with Lake Ontario or Pacific fish-supplemented diets for 13 weeks. No deaths were observed. Decreased spleen weights were observed in groups of males fed 1.45%, 5.8% Lake Ontario and 2.9% Pacific diet. After a 13 week recovery the spleen weights returned to normal. Decreased serum potassium was observed in male rats fed 2.9% Lake Ontario diet, and all levels of Pacific diet for 13 weeks, and was not evident following maintenance on normal diet. Serum glucose was not affected by the 13-week period of treatment, however; a reduction in this parameter occurred in male rats fed the two highest doses of Lake Ontario diet and all doses of Pacific diet following the 13-week recovery period. Minor hematological changes occurred only in the male rats fed either Lake Ontario or Pacific diet following a 13 week recovery period and included reduced marrow myeloid cells and myeloid/erythroid ratio. Hepatic microsomal ethoxyresorufin deethylase activity was significantly increased in rats ingesting Lake Ontario diet. Mild histological changes occurred in the liver and thyroid of the treated males, and in the liver and kidney of the treated females. These changes were attributed to the chemical residues and/or the fish diet. Data presented here indicated that the Lake Ontario fish-supplemented diet can cause mild biochemical, hematological and histological changes but most of these were reversible when exposure was terminated.

Animals↗
PubMedDate not supplied

Augmented in vitro presentation of Mls determinants after anti-immunoglobulin-induced B cell activation: ontogeny and role of purified B cells.

Murine splenocytes which contained B cells activated by in vivo exposure to affinity-purified goat anti-mouse IgD (GaMD) antibody were utilized to present major histocompatibility complex (MHC) and non-MHC minor lymphocyte-stimulating (Mlsa) determinants in a primary mixed lymphocyte reaction (MLR). As the time in hours after in vivo exposure to GaMD increased, splenocytes from adult mice showed a co-ordinate increase in cell size, expression of public and private MHC class II antigenic determinants and MHC and Mlsa antigen-presenting capacity. This augmented alloantigen-presenting capacity was demonstrable with either irradiated or mitomycin C-treated adult splenocytes. In contrast, GaMD-treated neonatal splenocytes from 10-day-old mice demonstrated no significantly increased class II expression or enhanced MHC stimulatory capacity, but nevertheless triggered augmented responder cell proliferation across an Mlsa barrier. Thus, increased class II expression or presenting capacity may not be required for an augmentation in splenocyte Mls-stimulating ability to occur. In vitro exposure of T cell-depleted splenocytes or highly purified small resting B cells to GaMD or lipopolysaccharide (LPS) induced a substantially increased ability in those populations to present MHC and Mlsa antigens in a primary MLR. Hence in vivo or in vitro activation of B lymphocytes in a stimulator cell population may yield more effective presentation of MHC and non-MHC determinants.

Animals↗
PubMedDate not supplied

Rey Auditory Verbal Learning Test performance of a Federal corrections sample with acquired immunodeficiency syndrome.

The Rey Auditory-Verbal Learning Test (AVLT) was administered to 30 inmates from three United States Federal corrections facilities. Fifteen were HIV seropositive and carried a diagnosis of AIDS; 15 were seronegative controls. The groups were comparable in age, education, sex, estimated premorbid IQ, and ethnic make-up. Both groups learned across trials, and produced similar acquisition curves. They also showed equivalent registration, but controls performed significantly better than subjects with AIDS on AVLT Trials II, IV, V, Recognition, and sum of I through V. AIDS subjects made significantly more intrusion errors than controls, suggesting that seropositive inmates performed more poorly, at least in part, because they experienced difficulty discriminating relevant from irrelevant responses during recall. Evaluation of serial position effects suggested that AIDS subjects experienced recall problems only with the middle segment of the word list. This finding may be unique to persons with AIDS and is consistent with the view that distinct clinical groups produce different recall patterns.

Acquired Immunodeficiency Syndrome↗