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Biomedical subjects

C Fletcher

Publications and source records attributed to C Fletcher.

At least 55 records · Page 3Linked to original sources
PubMed1992

Antibodies against somatic antigens and excreted/secreted products of Brugia pahangi in rats with patent and non-patent infections.

The humoral responses of Sprague-Dawley rats infected with Brugia pahangi were examined for up to 6 months after infection by ELISA, immunoblotting, and IFAT. In 2 experiments, 50% and 62.5% of rats developed patent, microfilaraemic infections. Mean adult worm burdens at autopsy were approximately 2% of the inoculum, and only patent rats yielded living adult worms. IgG antibody levels against crude somatic extracts (CSE) of all parasite stages and against adult excreted/secreted (ES) products were significantly higher in patent than non-patent rats. Both patent and non-patent rats produced anti-microfilarial surface antibody, as revealed by immunofluorescence. Immunostaining of Western blots by early infection sera showed no consistent difference in recognition of infective larval (L3) antigenic components by IgG or IgM antibody between eventually-patent and eventually-non-patent rats. By 26 weeks, however, patent rats recognized more components. The data suggest that antibodies against L3, adult, and microfilarial somatic antigens, ES antigens and microfilarial surface antigens do not correlate with the subsequent development of microfilaraemia in any individual rat.

Animals↗
PubMed1992

Shamed into anger? The relation of shame and guilt to anger and self-reported aggression.

The relation of shame and guilt to anger and aggression has been the focus of considerable theoretical discussion, but empirical findings have been inconsistent. Two recently developed measures of affective style were used to examine whether shame-proneness and guilt-proneness are differentially related to anger, hostility, and aggression. In 2 studies, 243 and 252 undergraduates completed the Self-Conscious Affect and Attribution Inventory, the Symptom Checklist 90, and the Spielberger Trait Anger Scale. Study 2 also included the Test of Self-Conscious Affect and the Buss-Durkee Hostility Inventory. Shame-proneness was consistently correlated with anger arousal, suspiciousness, resentment, irritability, a tendency to blame others for negative events, and indirect (but not direct) expressions of hostility. Proneness to "shame-free" guilt was inversely related to externalization of blame and some indices of anger, hostility, and resentment.

Adolescent↗
PubMed1992

Cats with single Brugia pahangi infections: relationship between parasitological status and humoral responses to somatic and surface parasite antigens.

Cats given a single inoculation of Brugia pahangi infective larvae (L3) were retrospectively allocated into three groups according to parasitological outcome of infection. Recognition of somatic and surface antigens of B. pahangi by sera from each group was compared by ELISA, immunoelectroblotting, and immunoprecipitation techniques. In cats that never became microfilaraemic mean serum IgG antibody levels against somatic extracts from adult male worms, L3, and microfilariae (mf) were higher than levels in cats that initially became microfilaraemic (mf + ve) then spontaneously became nonmicrofilaraemic (mf - ve). The lowest levels of antibody against each stage were found in cats that remained persistently mf + ve. Antigenic components of 18 kD and 22 kD in somatic extracts of adult worms and L3 were recognized by sera from cats that never became mf + ve and by spontaneously mf - ve cats, but not by sera of persistently mf + ve cats. When radioiodinated surface antigens of mixed adult worms and microfilariae were immunoprecipitated by sera from cats in the three groups, no correlation was observed between recognition of individual antigen components and parasitological outcome of infection.

Animals↗
PubMed1991

RJR Nabisco's cartoon camel promotes camel cigarettes to children.

OBJECTIVES: To determine if RJR Nabisco's cartoon-theme advertising is more effective in promoting Camel cigarettes to children or to adults. To determine if children see, remember, and are influenced by cigarette advertising. DESIGN: Use of four standard marketing measures to compare the effects of Camel's Old Joe cartoon advertising on children and adults. SUBJECTS: High school students, grades 9 through 12, from five regions of the United States, and adults, aged 21 years and over, from Massachusetts. OUTCOME MEASURES: Recognition of Camel's Old Joe cartoon character, product and brand name recall, brand preference, appeal of advertising themes. RESULTS: Children were more likely to report prior exposure to the Old Joe cartoon character (97.7% vs 72.2%; P less than .0001). Children were better able to identify the type of product being advertised (97.5% vs 67.0%; P less than .0001) and the the Camel cigarette brand name (93.6% vs 57.7%; P less than .0001). Children also found the Camel cigarette advertisements more appealing (P less than .0001). Camel's share of the illegal children's cigarette market segment has increased from 0.5% to 32.8%, representing sales estimated at $476 million per year. CONCLUSION: Old Joe Camel cartoon advertisements are far more successful at marketing Camel cigarettes to children than to adults. This finding is consistent with tobacco industry documents that indicate that a major function of tobacco advertising is to promote and maintain tobacco addiction among children.

Adolescent↗
PubMed1991

Characterization and functional expression of a cDNA encoding egasyn (esterase-22): the endoplasmic reticulum-targeting protein of beta-glucuronidase.

Egasyn (esterase-22), a member of the nonspecific carboxylesterase multigene family (E.C. 3.1.1.1), is the endoplasmic reticulum (ER)-targeting protein of beta-glucuronidase. We utilized the polymerase chain reaction (PCR) in the eventual isolation of murine egasyn cDNAs. PCR primers were based upon: (1) partial amino acid sequences derived from egasyn peptides and (2) a conserved active site region shared by carboxylesterases. The amino acid sequence deduced from the PCR product matched that obtained from egasyn protein. This product was utilized as a probe to screen a cDNA library. Two cDNAs whose composite sequence encoded an open reading frame of 562 amino acids were isolated. A message size of 1700-2000 bp was revealed by RNA blot hybridization analysis. S1 nuclease protection analyses detected mRNA in liver, kidney, lung, and submandibular gland, but not in spleen, brain, and testes. Genetic mapping confirmed the location of an egasyn cDNA fragment in cluster 1 of the esterase region on chromosome 8. Transfection of COS cells with the 2022-bp cDNA resulted in the expression of esterase activity, which comigrated on native gels with liver esterase-22. The features of the deduced amino acid sequence of the egasyn cDNA are compared with previously characterized carboxylesterases and with other lumenal ER proteins.

Amino Acid Sequence↗
PubMed1991

Genetic mapping of the lurcher locus on mouse chromosome 6 using an intersubspecific backcross.

The lurcher (Lc) mutant mouse strain exhibits postnatal degeneration of cerebellar Purkinje cells. We have typed progeny from an intersubspecific, phenotypic backcross at seven loci to develop a genetic linkage map which spans approximately 35 cM surrounding and including the Lc locus on mouse chromosome 6. [(Mus musculus castaneus x B6CBA-Aw-J/A-Lc)F1 x B6CBA-Aw-J/A]N2 progeny were scored visually for the lurcher phenotype and molecularly, through restriction fragment length polymorphism analysis, for six cloned markers. Two candidate genes, Npy and Pcp-1, which map to mouse chromosome 6 and which are expressed in the cerebellum, are demonstrated to be distinct from Lc. Three genes are shown to be closely linked to the Lc locus, and the map order cen-Cpa-Npy-Cbl-1-Lc-Igk, Fabpl-Pcp-1 is determined. The molecular genetic linkage map presented here represents progress toward isolating a clone of the Lc gene.

Animals↗
PubMed1991

Genetic mapping of meander tail, a mouse mutation affecting cerebellar development.

The meander tail mouse harbors a recessive mutation on chromosome 4 that affects the anterior lobes of the cerebellum and the caudal vertebrae. Examination of the mea/mea cerebellum reveals that the complete disorganization of all cell types seen in the anterior lobes is separated by a sharp and consistent boundary from the normal cytoarchitecture of the posterior lobes. In the absence of any biochemical information regarding the affected gene product, attempts to clone the gene must rely on the strategy of reverse genetics. As an initial step in this process we have constructed a genetic linkage map spanning 68 cM of chromosome 4 using an intersubspecific phenotypic backcross. The loci included in this analysis are Calb, Ggtb, Lv, b, Ifa, mea, D4Rp1, Glut-1, Lck, Lmyc-1, and Eno-1. This analysis positions the mea phenotypic locus in the interval between Ifa and Glut1. These results also further define regions of homology between mouse chromosome 4 and human chromosomes 8, 1, and 9. This linkage map provides the means to evaluate candidate genes, and to identify tightly linked markers useful for cloning the meander tail locus.

Animals↗
PubMed1991

A multilocus linkage map of mouse chromosome 8.

We present a genetic linkage map of mouse chromosome 8 that spans 53 cM and includes eight cloned loci. This map was derived from analysis of 100 progeny of an interspecific backcross between Mus spretus and Mus musculus domesticus. Genes that were mapped in this analysis include L7, Plat, Lpl, Ucp, Es, Mt-1, Um, and Tat. This analysis positions a new extremely proximal marker on chromosome 8, which is discussed as a potential candidate gene for the nervous locus. These linkage data will be useful for the mapping of additional loci on chromosome 8.

Animals↗
PubMed1991

Expression of members of the myf gene family in human rhabdomyosarcomas.

Northern analysis of tumour RNA has been used to examine the expression of members of the myf family of muscle determining genes (myf3, myf4, myf5 and myf6) in a series of 20 rhabdomyosarcomas. A 2.0 kb myf3 transcript was observed in 85% of tumours, a 1.8 kb myf4 transcript was detected in 70% of tumours and a 1.7 kb myf5 transcript was observed in 55% of tumours. Transcription of myf6 occurred in 28% of tumours, but there were several transcript sizes (1.2, 1.5, 2.0 and 3.5 kb) and in some individual tumours two or more transcripts were observed. Only two rhabdomyosarcomas, one classified as embryonal and one as pleomorphic, failed to exhibit transcription of members of the myf gene family. We were unable to detect transcription of myf genes in neuroblastomas, Wilms' tumours, hepatoblastomas, paediatric non-Hodgkin's lymphoma and leiomyosarcomas. When considered together these observations suggest that expression of myf genes could provide an extremely useful marker in the diagnosis of rhabdomyosarcoma.

Adolescent↗
PubMed1990

Meander tail reveals a discrete developmental unit in the mouse cerebellum.

Analyses of phenotypic mutations with altered patterns of cellular organization in invertebrate systems have lead to the identification of genes important to histogenesis. Efforts to identify genes defining segments or compartments in mammalian systems and demonstrate a role for such genes in the establishment of the cellular architectonics of the brain have been hampered by the absence of phenotypic mutations that reveal compartments. Evidence is presented that in the cerebellum of the mutant mouse, meander tail, there is an abrupt transition from the normal cytoarchitecture seen in the posterior lobes to a severely disorganized cellular pattern. Thus, in the anterior lobes the Purkinje cells are positioned randomly throughout the cortex, and other cellular layers, including the internal granule cell layer, do not form. In addition, radial Bergmann glial processes are virtually absent. One explanation for the discrete boundary of the affected area in the anterior portion of this mutant cerebellar cortex is that the meander tail gene influences compartmental cellular organization in mammalian brain.

Animals↗
PubMed1990

Primary sarcoma of the lung: potential dangers of immunocytochemistry.

A case is presented of a successfully resected primary pulmonary sarcoma in a 27-year-old man, followed by an eight-year disease-free follow-up. Details of the histological findings are presented, and the factors associated with good prognosis discussed. Immunocytochemical stains were carried out this year when the case was reviewed, and not at the time of resection. Had the immunostains been available at the time, the results would have suggested that the tumour might be a secondary deposit, and so have caused needless anxiety to the patient and his physicians.

Adult↗
PubMed1989

Organization of DNA in cerebellar neurons of ageing unirradiated and irradiated rats.

Male Fischer 344 rats were either unirradiated or whole-brain irradiated with single doses of 10.83 or 17.16 Gy of X-rays at 4 months of age, and the organization of the DNA in permanently non-dividing cerebellar neurons examined as a function of age, dose and time after irradiation. In unirradiated rats and rats receiving a whole-brain dose of 10.83 Gy, there were no statistically significant changes in the organization of the bulk DNA and its association with the nuclear matrix as determined by: (a) the sensitivity of the DNA to digestion by micrococcal nuclease, (b) the sensitivity of the nuclear matrix-associated DNA to digestion by DNase I, (c) the relative DNA and protein content of undigested neuronal nuclei, and (d) the relative amount of DNA and protein that is tightly associated with the nuclear matrix after digestion with DNase I. In rats that were irradiated with 17.16 Gy at 4 months of age, there was a gradual decrease in the amount of nuclear proteins as a function of age (P less than 0.003). The amount of protein associated with the nuclear matrix in these irradiated aging rats was also consistently lower than that of their unirradiated counterparts (P less than 0.03). This decrease in the nuclear protein content of the cerebellar neurons in aging rats irradiated with 17.16 Gy may have caused a change in the overall organization of their neuronal DNA. Such a change in the organization of their neuronal DNA was indicated by a higher stainability of their bulk DNA by propidium iodide (P less than 0.03) and a higher sensitivity of the bulk DNA to digestion by m. nuclease (P = 0.087). Although these organizational changes in the neuronal DNA of aging rats irradiated with 17.16 Gy at 4 months of age are subtle, they might alter DNA repair processes or other neuronal functions that may be associated with the "natural" process of aging.

Animals↗
PubMed1989

An apparatus to retain the spatial orientation of breast biopsies.

An apparatus has been designed to retain the spatial orientation of breast biopsies throughout surgery, transport and processing in the pathology laboratory. It does not interfere with regular surgical procedures and simplifies the surgeon's task of marking the orientation of a specimen. As the use of the apparatus does not involve either chemical or physical substances it is an appropriate handling procedure for those specimens requiring sensitive testing procedures such as cell culture.

Biopsy↗
PubMed1989

Renal subcapsular islet cell transplantation in the dog. A preliminary report.

During the last two decades, islet cell transplantation has been pursed both experimentally and clinically in an effort to ameliorate diabetes mellitus. At present, however, islet cell transplantation still remains at the experimental stages as far as the treatment of diabetes is concerned. Also, culture of islet cells has proved to be rather frustrating and difficult. No consistent techniques have been developed, and simplified methods for islet cell preparation and adequate sites for islet cell placement would allow for further progress in this area. Ultimately, rejection remains the greatest obstacle to success. We report a simplified technique for enriching dog pancreatic islet cells. This preparation was injected into the renal subcapsular space in both homograft (3 experiments) and heterograft (3 experiments) situations. After six weeks, nephrectomy was performed, and histochemical techniques demonstrated many groups of live islets in between the tubules in the renal cortex. No acinar cells were observed. Blood samples from the renal artery and renal vein at the time of nephrectomy revealed an average 36.9% increase in insulin concentration in the renal veins, supporting an active secretory role of these transplanted islet cells. This technique points to (i) the possible role of "renal factor" in promoting growth of islet cells and (ii) the feasibility of successful transplantation of enriched islet cells as a potential approach to the curative treatment of diabetes mellitus.

Animals↗