The social psychology of amateur ethicists: blood product recall notification and the value of reflexivity.

The purpose of this article is to highlight ways in which institutional policymakers tend to insufficiently conceptualise their role as ethics practitioners. We use the case of blood product recall notification as a means of raising questions about the way in which, as we have observed it, discourse for those who make institutional ethics policies is constrained by routine balancing of simplified principles to the exclusion of reflexive practices-those that turn ethics reasoning back on itself. The latter allows ethics practitioners with comparatively little formal training to take ownership of traditional parameters, which define their discussions and ultimately ought to make them more insightful when doing ethics. Thus, in the midst of calls for more training to increase the competency of ethics committees, we suggest that an additional problem of how these lay ethicists conceive of their roles also needs to be addressed.

Cellular Concentrations and Uniformity of Cell-Type Accumulation of Two Lea Proteins in Cotton Embryos.

The levels and cell-type distribution of late embryogenesis abundant (Lea) proteins D-7 and D-113 have been determined in mature cotton embryos by immunochemical methods. The two proteins were expressed in and purified from Escherichia coli and utilized for antibody production in rabbits. The antiserum to each protein was found to interact with all members of each protein family in cotton extracts by protein gel blotting. Using these antibodies in quantitative "rocket" immunoelectrophoreses, D-7 proteins were found to accumulate to ~8 x 1015 molecules per embryo, which is equivalent to ~109 molecules per "average cell." D-113 proteins accumulate to ~1016 molecules per embryo, which equates to ~1.3 x 109 molecules per average cell. These values calculate to concentrations of about 226 and 283 [mu]M, respectively, in the cell aqueous phase immediately prior to seed desiccation. In immunocytochemical studies using the fluorophor rhodamine linked to the secondary antibody, both proteins appeared to be evenly present in the cytosol of all cell types present in the embryo, including both cotyledon and axis epidermal cells. Thus, their function does not appear related to unique functions of specific cell or tissue types. The very high molar concentrations of the two proteins, coupled with their unusual predicted structure and their cytosol location, would seem to reduce the number of their conceivable functions.

The developmental biochemistry of cotton seed embryogenesis and germination. VI. Levels of cytosol and chloroplast aminoacyl-tRNA synthetases during cotyledon development.

The separation of isotransferring aminoacyl-tRNA synthetase activities (amino acid: tRNA ligases, EC 6.1.1.x) for several amino acids extracted from tissues of embryonic and germinating cotton seeds was carried out by DEAE-cellulose column chromatography. Evidence was obrained that the separated activities represent discrete enzymes, and could be defined as cytosol or chloroplast enzymes by several criteria. The levels of the cytosol enzymes per cell were found to be constant in germinated and ungerminated cotyledons. Chloroplast enzymes were found to be present in immature embryonic cotyledons and in roots at constant levels relative to the cytosol enzymes, but found to increase markedly in germinating cotyledons. This increase takes place to the same extent in etiolated cotyledons as in greened cotyledons indicating that the chloroplast synthetase increase is analogous to the simultaneous increase in chloroplast tRNA and rRNA which also is not light dependent. The separated cytosol and chloroplast enzymes show varying degrees of specificity for isoaccepting tRNA species from homologous and heterologous sources.

Clinical and genetic heterogeneity in benign hereditary chorea.

BACKGROUND: Benign hereditary chorea (BHC) is an autosomal dominant disorder that can be distinguished from Huntington disease by its early onset, stable or only slightly progressive course, and absence of mental deterioration. The variation in clinical features is such that its very existence has been doubted. The authors recently described the localization of a gene responsible for BHC on chromosome 14q in a large Dutch family. OBJECTIVE: To report results of extensive clinical and linkage analyses for this Dutch family and six other families with BHC. RESULTS: Three of the seven families had linkage to a region on chromosome 14q13.1-q21.1. HOMOG analysis showed odds of 10 x 10(11) in favor of locus heterogeneity. Haplotype analyses for the linked families resulted in a reduction of the critical interval for the BHC gene to 8.4 cM between marker D14S49 and marker D14S278. Clinically, these three families had a homogeneous picture with early-onset chorea, sometimes accompanied by slight ataxia in walking, but without dystonia, myoclonic jerks, or dysarthria. The severity of the choreatic movements tended to abate in adolescence or early adulthood. In the unlinked families, symptoms and signs were more heterogeneous as to age at onset and the occurrence of myoclonic jerks or dystonia. CONCLUSIONS: BHC is a clinically and genetically heterogeneous disorder, with one well-defined clinical syndrome mapping to chromosome 14q.

Excitatory amino acid binding sites in the basal ganglia of the rat: a quantitative autoradiographic study.

Quantitative receptor autoradiography was used to determine the distribution of excitatory amino acid binding sites in the basal ganglia of rat brain. alpha-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid, N-methyl-D-aspartate, kainate, quisqualate-sensitive metabotropic and non-N-methyl-D-aspartate, non-kainate, non-quisqualate glutamate binding sites had their highest density in striatum, nucleus accumbens, and olfactory tubercle. Kainate binding was higher in the lateral striatum but there was no medial-lateral striatal gradient for other binding sites. N-Methyl-D-aspartate and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid binding sites were most dense in the nucleus accumbens and olfactory tubercle. There was no dorsal-ventral gradient within the striatal complex for the other binding sites. Other regions of the basal ganglia had lower densities of ligand binding. To compare binding site density within non-striatal regions, binding for each ligand was normalized to the striatal binding density. When compared to the striatal complex, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid and metabotropic binding sites had higher relative density in the globus pallidus, ventral pallidum, and subthalamic nucleus than other binding sites. Metabotropic binding also had a high relative density in the substantia nigra. Non-N-methyl-D-aspartate, non-kainate, non-quisqualate glutamate binding sites had a high relative density in globus pallidus, ventral pallidum, and substantia nigra. N-Methyl-D-aspartate binding sites had a low relative density in pallidum, subthalamic nucleus, substantia nigra and ventral tegmental area. Our data indicate heterogeneous distribution of excitatory amino acid binding sites within rat basal ganglia and suggest that the character of excitatory amino acid-mediated neurotransmission within the basal ganglia is also heterogeneous.

IT15 gene expression in fetal human brain.

To examine the expression of the gene which causes Huntington's disease (HD), IT15, during development, in situ hybridization of radiolabeled riboprobes was performed in human fetal (gestational ages 20-23 weeks) and adult brain. Optical densities of autoradiographs were determined in various brain regions and compared to cell density in those regions. IT15 expression was found in all regions of the fetal and adult brain, and there was a high degree of correlation of autoradiographic signal with cell number in all regions but germinal matrix in fetal brain and white matter in adult brain. These two regions are notable for their significant proportion of glial cells, and suggest that IT15 expression is predominantly neuronal. There was no preponderance of IT15 expression in striatal compartments in fetal brain as demonstrated by acetylcholinesterase activity, nor was there differential expression of IT15 in brain regions known to be particularly affected in HD. IT15 gene expression is present by 20 weeks gestation in human brain, and at that stage of development exhibits a pattern of distribution which is similar to adult brain. If a developmentally-regulated role for IT15 exists in the pathogenesis of HD, it must occur prior to 20 weeks gestation.

Excitatory amino acid binding sites in the periaqueductal gray of the rat.

We used receptor autoradiography to determine the distribution of excitatory amino acid (EAA) binding site subtypes in the periaqueductal gray (PAG) of the rat. N-Methyl-D-aspartate (NMDA), kainate, quisqualate-ionotropic, and quisqualate-metabotropic binding sites were all present in the PAG. Distribution was inhomogeneous with greatest density of all binding site subtypes in the dorsolateral subdivision and lowest density in the ventrolateral subdivision. Relative to regions of brain with high densities of EAA binding site subtypes, quisqualate-metabotropic binding sites had the highest relative density and NMDA binding sites the least. The presence of all subtypes of EAA binding sites in the PAG suggests that EAA action within the PAG is likely to be complex.

Is cell death necessary for hippocampal mossy fiber sprouting?

To examine the relationship between cell death and sprouting of the mossy fibers, repeated seizures of the hippocampal-parahippocampal circuit were elicited in anesthetized rats. The presence of mossy fiber growth was assessed with the Timm's stain for zinc. At 4 weeks, after 18 repeated seizures, there was a significant increase in the degree of zinc containing granules in the inner molecular layer of the dentate gyrus. The amount of sprouting was less than that seen four weeks after a single injection of kainic acid. A silver impregnation stain and an assay for damaged DNA were used to detect damaged or dying neurons and immunohistochemistry for a 72 kDa heat shock protein was used to detect any neurons that had suffered potentially injurious stress. The same number of repeated seizures that caused sprouting of the mossy fibers did not cause detectable cell death or severe stress in any cells within the hippocampus, subicular region or adjacent entorhinal cortex. These experiments demonstrate that repeated seizures of the hippocampal-parahippocampal circuits can cause sprouting of mossy fibers in the absence of evidence of cell death. This supports the hypothesis that alterations in intrinsic neural excitability and impulse activity from the dentate gyrus can result in growth of axonal processes in the adult rat brain.

Trinucleotide repeats in neurologic diseases: an hypothesis concerning the pathogenesis of Huntington's disease, Kennedy's disease, and spinocerebellar ataxia type I.

Three neurodegenerative diseases, Huntington's disease (HD), Kennedy's disease (hereditary spinobulbar muscular atrophy, SBMA), and type 1 spinocerebellar ataxia (SCA-1) have been found to share a common genetic defect: an unstable region of repeated CAG trinucleotides which are thought to be translated into a polyglutamine moiety. The unstable repeat regions occur near the N-termini of the predicted proteins for HD and SBMA, but the location of the CAG repeat region is not known for SCA-1. Each disease is notable for a relatively circumscribed region of central nervous system pathology, and the lack of predicted similarity of the abnormal proteins makes a common mechanism related to the function of each protein unlikely. In order to reconcile the similar genetic abnormalities with the disparities in phenotypes, we suggest a common thread with regard to the pathogenesis of neuronal death. We hypothesize that the mechanism of neurotoxicity in these diseases occurs not through the production of abnormal proteins, but by the generation of abnormal posttranslational cleavage products. These products, in part consisting of abnormally large polyglutamine moieties, act to disturb the cellular and mitochondrial milieu such that energy metabolism is impaired, rendering specific regions of the nervous system vulnerable, and resulting in the clinical phenotypes of HD, SBMA, and SCA-1. We offer this interpretation of recent genetic findings from a neurobiologic perspective, in addition to suggesting testable hypotheses concerning potential disease mechanisms.

Neonatal encephalopathy in two boys in families with recurrent Rett syndrome.

Rett syndrome (RTT) has been described in its classic form only in females. Although the majority of cases are sporadic, familial cases give valuable insight into the genetic basis and phenotypic variability of the disorder. The exclusive occurrence of classic Rett syndrome in females led to the hypothesis that the Rett syndrome locus is likely to be X-linked and mutations are lethal in hemizygous males. We identified two boys in families with recurrent Rett syndrome who had encephalopathies with neonatal onset and who may represent the phenotype of males harboring Rett syndrome mutations. The difference in severity of disease in these males and their female relatives supports the location of Rett syndrome locus on the X-chromosome.

Quantifying physical decline in juvenile neuronal ceroid lipofuscinosis (Batten disease).

OBJECTIVE: To use the Unified Batten Disease Rating Scale (UBDRS) to measure the rate of decline in physical and functional capability domains in patients with juvenile neuronal ceroid lipofuscinosis (JNCL) or Batten disease, a neurodegenerative lysosomal storage disorder. We have evaluated the UBDRS in subjects with JNCL since 2002; during that time, the scale has been refined to improve reliability and validity. Now that therapies are being proposed to prevent, slow, or reverse the course of JNCL, the UBDRS will play an important role in quantitatively assessing clinical outcomes in research trials. METHODS: We administered the UBDRS to 82 subjects with JNCL genetically confirmed by CLN3 mutational analysis. Forty-four subjects were seen for more than one annual visit. From these data, the rate of physical impairment over time was quantified using multivariate linear regression and repeated-measures analysis. RESULTS: The UBDRS Physical Impairment subscale shows worsening over time that proceeds at a quantifiable linear rate in the years following initial onset of clinical symptoms. This deterioration correlates with functional capability and is not influenced by CLN3 genotype. CONCLUSION: The UBDRS is a reliable and valid instrument that measures clinical progression in JNCL. Our data support the use of the UBDRS to quantify the rate of progression of physical impairment in subjects with JNCL in clinical trials.

Early progressive encephalopathy in boys and MECP2 mutations.

MECP2 mutations mainly occur in females with Rett syndrome. Mutations have been described in 11 boys with progressive encephalopathy: seven of nine with affected sisters and two de novo. The authors report four de novo occurrences: three pathogenic and one potentially pathogenic. Common features include failure to thrive, respiratory insufficiency, microcephaly, and abnormal motor control. MECP2 mutations should be assessed in boys with progressive encephalopathy and one or more of respiratory insufficiency, abnormal movements or tone, and intractable seizures.

A clinical rating scale for Batten disease: reliable and relevant for clinical trials.

BACKGROUND: Batten disease (juvenile neuronal ceroid lipofuscinosis [JNCL]) is an autosomal recessive neurodegenerative disorder characterized by blindness, seizures, and relentless decline in cognitive, motor, and behavioral function. Onset is in the early school years, with progression to death typically by late adolescence. Development of a clinical instrument to quantify severity of illness is a prerequisite to eventual assessment of experimental therapeutic interventions. OBJECTIVE: To develop a clinical rating instrument to assess motor, behavioral, and functional capability in JNCL. METHODS: A clinical rating instrument, the Unified Batten Disease Rating Scale (UBDRS), was developed by the authors to assess motor, behavioral, and functional capability in JNCL. Children with verified JNCL were evaluated independently by three neurologists. Intraclass correlation coefficients (ICCs) were used to estimate the interrater reliability for total scores in each domain. Interrater reliability for scale items was assessed with weighted kappa statistics. RESULTS: Thirty-one children with confirmed JNCL (10 boys, 21 girls) were evaluated. The mean age at symptom onset was 6.1 +/- 1.6 years, and the mean duration of illness was 9.0 +/- 4.4 years. The ICCs for the domains were as follows: motor = 0.83, behavioral = 0.68, and functional capability = 0.85. CONCLUSIONS: The Unified Batten Disease Rating Scale (UBDRS) is a reliable instrument that effectively tests for neurologic function in blind and demented patients. In its current form, the UBDRS is useful for monitoring the diverse clinical findings seen in Batten disease.