Maturation of peroxisomes in differentiating human hepatoblastoma cells (HepG2): possible involvement of the peroxisome proliferator-activated receptor alpha (PPAR alpha)

Although several variant alleles at the human NAT1 gene locus have been reported, their relationship to phenotypic variations in NAT1 function remains unclear. We have used in-vivo and invitro phenotyping tests, along with PCR-based cloning and heterologous expression, to investigate the extent of variation in NAT1 function and to characterize novel allelic variants at the NAT1 gene locus. The NAT1-selective substrate p-aminosalicylic acid (PAS) was used as a probe for NAT1 function. In-vivo PAS acetylation rates were estimated by determining the ratio of PAS to N-acetylated PAS (AcPAS) in urine and plasma following the oral ingestion of Nemasol Sodium. Excluding outliers, a 65-fold variation in the urinary AcPAS:PAS ratio was observed (n = 144), while a 5.6-fold variation in the plasma AcPAS:PAS ratio was seen in a subset (n = 19) of this sample. Urinary and plasma ratios correlated moderately (r = 0.74, p < 0.0005). One individual (case 244) had a marked impairment of PAS N-acetylation, with 10-fold lower urinary and plasma AcPAS:PAS ratios compared with other subjects. Biochemical investigations in whole blood lysates from case 244 suggested a NAT1 kinetic defect, with a 20-fold increased apparent K(m) for PAS and a 90-fold decreased Vmax for AcPAS formation. We subcloned, sequenced and expressed the protein-coding regions of the NAT1 alleles from case 244 and from seven other selected probands. Sequence analysis revealed the presence of two new variant alleles, designated as NAT1 x 14 and NAT1 x 15, in case 244, as well as one variant, NAT1 x 11, which has been observed in previous investigations. NAT1 x 14 contained a missense mutation (G560-->A) that is predicted to change a single amino acid (Arg187-->Gln), as well as two 3' non-coding region mutations (T1088-->A and C1095-->A) that have previously been observed in the NAT1 x 10 allelic variant. NAT1 x 15 had a single nonsense mutation (C559-->T; Arg187-->stop) and, thus, encodes a truncated protein. The activity of recombinant NAT1 14 mirrored the defective enzyme function in whole blood lysates from case 244, while NAT1 15 was completely inactive. Expressed NAT1 11, on the other hand, had identical activity to the wild type NAT1 4 allele, suggesting that the coding region mutations in this variant are functionally silent. The frequencies of NAT1 x 11, NAT1 x 14 and NAT1 x 15 were 0.021, 0.028 and 0.014 (n = 288 alleles), respectively, suggesting that they are relatively rare in our predominantly Caucasian sample.     

Misconceived sources of opposition to physician-assisted suicide.

This article addresses 2 prominent sources of opposition to physician-assisted suicide (PAS): first, the fear of abuse and, second, common moral distinctions drawn between PAS and other forms of end-of-life decisions and care. Each is grounded in a false assumption that PAS is radically different from other forms of widely accepted end-of-life decisions and care. The experience to date in Oregon gives some reassurance that the practice there permitting PAS has not been significantly abused. Moreover, the author argues that abuse, understood as decisions not in accord with what the patient wants, or would have wanted, is greatest when someone, other than the patient is the decision maker. On this ground, PAS should be less subject to abuse than other surrogate decisions about life support. Moreover, Oregon's law, like virtually all proposals to legalize PAS, contains numerous safeguards that are not present in decisions about life support generally. Second, it is argued that some prominent conceptualizations of accepted end-of-life decisions and care thought to distinguish them morally from PAS fail on closer analysis to do so. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Photoactive yellow protein: a structural prototype for the three-dimensional fold of the PAS domain superfamily

PAS domains are found in diverse proteins throughout all three kingdoms of life, where they apparently function in sensing and signal transduction. Although a wealth of useful sequence and functional information has become recently available, these data have not been integrated into a three-dimensional (3D) framework. The very early evolutionary development and diverse functions of PAS domains have made sequence analysis and modeling of this protein superfamily challenging. Limited sequence similarities between the approximately 50-residue PAS repeats and one region of the bacterial blue-light photosensor photoactive yellow protein (PYP), for which ground-state and light-activated crystallographic structures have been determined to high resolution, originally were identified in sequence searches using consensus sequence probes from PAS-containing proteins. Here, we found that by changing a few residues particular to PYP function, the modified PYP sequence probe also could select PAS protein sequences. By mapping a typical approximately 150-residue PAS domain sequence onto the entire crystallographic structure of PYP, we show that the PAS sequence similarities and differences are consistent with a shared 3D fold (the PAS/PYP module) with obvious potential for a ligand-binding cavity. Thus, PYP appears to prototypically exhibit all the major structural and functional features characteristic of the PAS domain superfamily: the shared PAS/PYP modular domain fold of approximately 125-150 residues, a sensor function often linked to ligand or cofactor (chromophore) binding, and signal transduction capability governed by heterodimeric assembly (to the downstream partner of PYP). This 3D PAS/PYP module provides a structural model to guide experimental testing of hypotheses regarding ligand-binding, dimerization, and signal transduction.     

Monday and non-Monday concentrations of lifestyle-related blood components in the Oslo Diet and Exercise Study

CONTEXT: Despite intense debates about legalization, there are few data examining the details of actual euthanasia and physician-assisted suicide (PAS) cases in the United States. OBJECTIVE: To determine whether the practices of euthanasia and PAS are consistent with proposed safeguards and the effect on physicians of having performed euthanasia or PAS. DESIGN: Structured in-depth telephone interviews. SETTING AND PARTICIPANTS: Randomly selected oncologists in the United States. OUTCOME MEASURES: Adherence to primary and secondary safeguards for the practice of euthanasia and PAS; regret, comfort, and fear of prosecution from performing euthanasia or PAS. RESULTS: A total of 355 oncologists (72.6% response rate) were interviewed on euthanasia and PAS. On 2 screening questions, 56 oncologists (15.8%) reported participating in euthanasia or PAS; 53 oncologists (94.6% response rate) participated in in-depth interviews. Thirty-eight of 53 oncologists described clearly defined cases of euthanasia or PAS. Twenty-three patients (60.5%) both initiated and repeated their request for euthanasia or PAS, but 6 patients (15.8%) did not participate in the decision for euthanasia or PAS. Thirty-seven patients (97.4%) were experiencing unremitting pain or such poor physical functioning they could not perform self-care. Physicians sought consultation in 15 cases (39.5%). Overall, oncologists adhered to all 3 main safeguards in 13 cases (34.2%): (1) having the patient initiate and repeat the request for euthanasia or PAS, (2) ensuring the patient was experiencing extreme physical pain or suffering, and (3) consulting with a colleague. Those who adhered to the safeguards had known their patients longer and tended to be more religious. In 28 cases (73.7%), the family supported the decision. In all cases of pain, patients were receiving narcotic analgesia. Fifteen patients (39.5%) were enrolled in a hospice. While 19 oncologists (52.6%) received comfort from having helped a patient with euthanasia or PAS, 9 (23.7%) regretted having performed euthanasia or PAS, and 15 (39.5%) feared prosecution. CONCLUSIONS: Intractable pain or poor physical functioning seem to be nearly absolute requirements for physicians to perform euthanasia or PAS. Only one third of cases are performed consistently with proposed safeguards. For some patients, end-of-life care that includes opioid analgesia and hospice care does not obviate their desire for euthanasia or PAS. While the majority of physicians seem comforted by their actions, some experience adverse consequences from having performed euthanasia or PAS.     

Development and implementation of a perioperative autologous service program

Several months after we initiated our PAS program, the AABB scrutinized our policy and procedure manual. At the same time, the JCAHO conducted an inspection of our blood bank and its standards. Both reviews were positive, which provided all of us involved in the PAS program with a tremendous sense of accomplishment. Each PAS team member played a significant role in the development and implementation of our PAS program. Thanks to the energy, enthusiasm, and support of perioperative nurses, surgeons, and hospital administrators, our PAS program has evolved into a high quality, efficient alternative to homologous blood transfusions in the perioperative setting.     

Novel functional polymers: poly(dimethylsiloxane)-polyamide multiblock copolymer. V. The interaction between biomolecules and the surface of aramid-silicone resins

Multiblock copolymers consisting of aromatic polyamide(aramid) and poly(dimethylsiloxane) (PDMS) aramid-silicone resins (PASs) were synthesized by low temperature solution polycondensation, and PAS films were prepared by casting from an N,N'-dimethylacetamide solution. In this study, we investigated bovine serum albumin (BSA) adsorption, L929 cell adhesion, and tissue reaction on the surface of PAS in order to clarify the interaction between PAS and biomolecules. It was found that the amount of adsorbed biomolecules on PAS was extremely low in contrast with those on aramid and nylon films, and it was comparable to SILASTIC 500-1 film. This suppression of adsorption of biomolecules onto PAS seemed to be due to the low surface free energy of the outermost surface of PAS, where PDMS block was condensed.     

Expression of functional tissue factor on small vesicles of lipopolysaccharide-stimulated human vascular endothelial cells

An autopsy case of Sj?gren-Larsson syndrome (SLS), an 8-year-old boy, is presented with neuropathological investigations. Widespread deposition of 2 different types of unusual substances, stained lightly or strongly with periodic acid Schiff (PAS) was most conspicuous in this case. The first type of them, lightly stained with PAS at room temperature, was widely distributed in the central nervous system (CNS): the white matter of cerebrum and brainstem, subpial and subependymal glial layers, subpial space, perivascular space of small blood vessels, and their adjacent nervous tissue. The second type, strongly stained with PAS, small round or ellipsoid bodies, was found in the subpial, subependymal and perivascular glial layers. The first type of PAS-positive substances might be fatty alcohols or their metabolites, and the second type, some degraded products of lipids in astrocytic processes. Lipofuscin-like substances were accumulated in perivascular macrophages located around small blood vessels. Spheroid bodies (axonal swellings) were frequently observed in relay nuclei: lateral geniculate body (LGB), pontine nuclei, inferior olivary nuclei, posterior funicular nuclei, or cerebellar dentate nuclei. A lot of PAS-positive fine granules were contained in a spheroid body of LGB. Scarcity of myelinated nerve fibers was recognized in the cerebral and cerebellar white matter and the corticospinal tracts of spinal cord. Focal cortical dysgenesis, resembling that of unlayered polymicrogyria, was observed in bilateral insular cortices. Further histochemical studies are needed to explore the exact pathogenesis, but widespread deposition of PAS-positive substances in CNS may support the supposition that SLS is one of congenital errors of lipid metabolism.     

Gefarnate increases PAS positive cell density in rabbit conjunctiva

AIMS: The effects of three drugs for the treatment of gastritis and gastric ulcer--gefarnate, ecabet sodium, and troxipide--on periodic acid Schiff (PAS) positive cell density in rabbit conjunctiva in vivo were investigated. METHODS: Eye drops containing gefarnate (0.1%, 1%), ecabet sodium (0.1%, 1%), or troxipide (0.1%, 1%) were instilled in both eyes of rabbits, six times a day for 7 days. On the eighth day, filter paper was gently pressed on the bulbar and palpebral conjunctiva, and impression cytology was performed with PAS staining. Three points in each specimen were selected randomly, and PAS stained cells were counted. RESULTS: The instillation of gefarnate increased PAS positive cell density significantly at the concentration of 1% (p < 0.05). In contrast, instillation of ecabet sodium or troxipide failed to change PAS positive cell density. CONCLUSIONS: These results demonstrated that gefarnate stimulates PAS positive cell density in rabbit conjunctiva.     

Diagnostic value of echocardiography and thoracic spiral CT angiography in the diagnosis of acute pulmonary embolism

The objective of this study was to define the limits of echocardiography and to evaluate thoracic spiral CT angiography (TSCTA) for the diagnosis of pulmonary embolism (PE). One hundred twelve consecutive patients, hospitalised for suspected PE, were included in this prospective study. All were investigated by pulmonary ventilation-perfusion scintigraphy (Sc) and 50 had a high probability of PE on this examination. Sc was normal in 22 patients. Forty patients were excluded because of an intermediate probability. In 50 patients with PE confirmed on Sc, transthoracic echocardiography (TTE) showed only indirect evidence of PE (intracavitary thrombus in 4% of cases). TSCTA demonstrated PE in 82% of cases and did not show any thrombus image when Sc was normal. Its negative predictive value was therefore 70% and its positive predictive value was 100%. Its sensitivity varied according to degree of perfusion defect (96% in the case of lobar lesion, 66% in the case of segmental lesion and 16% for a subsegmental lesion). Multidimensional transoesophageal echocardiography (TOE), performed in 37 of the 50 patients with PE, only revealed thrombi in the pulmonary tree in 3 patients (8%), all presenting severe PE. No thrombus was visualized on TOE in patients with non-serious PE. All thrombi observed on TOE were also demonstrated by TSCTA. In conclusion, TTE usually provides only indirect signs of PE. TOE has a poor diagnostic sensitivity for PE. TSCTA has a better sensitivity than TOE for the detection of thrombi in the pulmonary artery trunk and proximal centimetres of its two branches, but normal CT angiography cannot exclude a distal PE.     

Mutation in the Arabidopsis PASTICCINO1 gene, which encodes a new FK506-binding protein-like protein, has a dramatic effect on plant development

The pasticcino (pas) mutants of Arabidopsis thaliana are a new class of plant developmental mutants; members of this class show ectopic cell proliferation in cotyledons, extra layers of cells in the hypocotyl, and an abnormal apical meristem. This phenotype is correlated with both cell division and cell elongation defects. There are three complementation groups of pas mutants (pas1, pas2, and pas3, with, respectively 2, 1, and 4 alleles). Here we describe in more detail the pas1-1 allele, which was obtained by insertional mutagenesis. The PAS1 gene has been cloned and characterized; it encodes an immunophilin-like protein similar to the p59 FK506-binding protein (FKBP52). PAS1 is characterized by an FKBP-like domain and three tetratricopeptide repeat units. Although the presence of immunophilins in plants has already been demonstrated, the pas1-1 mutant represents the first inactivation of an FKBP-like gene in plants. PAS1 expression is altered in pas1 mutants and in the pas2 and pas3 mutants. The expression of the PAS1 gene is increased in the presence of cytokinins, a class of phytohormones originally discovered because of their ability to stimulate cell division. These results are of particular relevance as they show for the first time that an FKBP-like protein plays an important role in the control of plant development.     

Genomic imprinting in the brain

Biopsies of cervix uteri from 166 patients with benign and malignant lesions (12 normal, 48 inflammatory lesion, 6 adenocarcinoma, 2 adenosquamous carcinoma and 98 from squamous cell carcinomas) were studied histochemically. The stains used were PAS with/without diastase, AB/PAS (pH 2.5) and OR/AB. In inflammatory lesions neutral mucin was predominent which was replaced by sialomucin and sulphomucin in endocervical polyps. In malignant lesions sulphomucin was predominent. Seventeen percent cases of squamous cell carcinomas needed reclassification after mucin staining. Of the fourteen large cell non-keratinizing squamous cell carcinomas, 12 were reclassified as squamous cell carcinoma with mucin secretion and 2 as adenosquamous carcinoma. One case of small cell non-keratinizing squamous cell carcinoma was reclassified as moderately differentiated adenocarcinoma. None of the keratinizing carcinomas had evidence of mucin secretion. Mucin histochemistry should be done routinely on non-keratinizing squamous cell carcinomas to pick up more cases of carcinoma with evidence of mucin secretion which can be missed on routine haematoxylin and eosin stains. Such carcinomas are known to pursue a more aggressive clinical course and have a poorer prognosis than non-mucin secreting type of squamous cell carcinoma.     

稀土色剂和釉瓷的光声光谱研究

光声光谱适于研究不透明、高反射、高散射的稀土色剂和釉瓷的光学性质。本文测定了Ｐｒ－Ｚｒ黄、Ｐｒ－Ｖ－Ｚｒ绿、Ｎｄ－Ｚｒ紫色剂和釉瓷的光声光谱，探讨了稀土离子的存在状态和着色机理，提出以谱图作为确定色调和判断质量的客观依据。     

Two complementary approaches to study peroxisome biogenesis in Saccharomyces cerevisiae: forward and reversed genetics

In order to investigate the mechanisms of peroxisome biogenesis and to identify components of the peroxisomal import machinery we studied these processes in the yeast Saccharomyces cerevisiae. The forward genetic approach has led to pas-mutants (peroxisomal assembly) which fall into 12 complementation groups and allowed to identify 10 of the corresponding wild-type PAS genes (PAS 1-7, 9, 11 and 12). Recent sequence analysis data of some of these genes are beginning to provide first hints as to the possible function of their gene products. The PAS genes and their corresponding mutants are presently used to address some important questions of peroxisomal biogenesis. Reversed genetics has been started as a complementary approach to characterize especially the function of peroxisomal membrane proteins. For this purpose we describe a technique to isolate highly purified peroxisomes. This led to the identification of 21 polypeptides as constituents of this organelle. Some of them are presently sequenced.     

Reaction time slowing during high-load, sustained-attention task performance in relation to psychometrically identified schizotypy.

Prior research has demonstrated a reliable deficit in performance accuracy (e.g.,d') on sustained-attention tasks in relation to psychometrically identified schizotypy and clinically diagnosed schizotypal psychopathology. The present study sought to expand the understanding of sustained-attention performance in relation to psychometric schizotypy through a study of reaction time (RT) performance. In this study, the author examined performance accuracy and RT on a high-load, sustained-attention task, the Continuous Performance Test—Identical Pairs (CPT—IP) version, in 31 high Perceptual Aberration Scale (PAS) and 26 normal control (control PAS) subjects from a large university population. High PAS (psychometric schizotypy) subjects displayed significantly longer RT performance on the CPT—IP relative to controls. The RT slowing was not explained by mental state or general intellectual ability factors. Contrary to expectation, a difference in performance accuracy (e.g.,d') was not observed between the groups; however, power and other considerations cloud the interpretation of this finding. The meaning of the observed RT slowing is examined and its relation to current models of the development of schizophrenia is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual organization and precategorical acoustic storage.

Current views of precategorical acoustic storage (PAS) have been largely based on differences in the level of recall of terminal list items as a function of input modality and on experiments in which various types of suffixes are added to unstructured auditory lists. Experiments with grouped lists reveal that PAS can make a far more extensive contribution to serial recall. A series of four experiments investigated grouping effects in relation to existing accounts of consolidation, attentional selection, and auditory masking in PAS. Grouping effects obtained with very brief intralist pauses were inconsistent with the consolidation and masking hypotheses. Contrary to the attentional hypothesis, nontemporal grouping by voice or by spatial location was found to be as effective as grouping by extended pauses. When nontemporal methods of grouping were combined with intralist pauses, the two sets of grouping cues were no better than one, suggesting that list segmentation by pauses and by item attributes must be explained in terms of a single process. These results are discussed in the context of previous research that implies the existence of an auditory store with a capacity greater than previously attributed to PAS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychosis proneness and clinical psychopathology: Examination of the correlates of schizotypy.

The present report examined the associations between the Perceptual Aberration Scale (PAS), a prominent psychometric index of hypothetical psychosis proneness, and several measures of clinical psychopathology in a nonpsychotic psychiatric sample (N?=?101). Patients were examined by experienced clinicians using structured psychiatric interviews to assess Diagnostic and Statistical Manual of Mental Disorders-III—Revised (DSM-III—R) Axis I and II conditions and rated for anxiety, depression, severity of illness, and current adult social competence. Elevated scores on the PAS were most closely associated with anxiety and depression as well as schizotypal, schizoid, avoidant, and obsessive–compulsive personality disorder symptomatology. Hierarchical regression analysis identified schizotypal symptoms and anxiety as the two underlying psychopathological processes most useful in explaining variance in PAS scores. Results are interpreted as supporting both the clinical relevance and research utility of the PAS and enhancing the construct validity of Meehl's model of schizotypy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Absence of the major sialoglycoprotein in the membrane of human En(a--) erythrocytes and increased glycosylation of band 3

The human En(a-) blood group is a rare recessive trait. These erythrocytes lack the major membrane sialoglycoprotein (PAS1, MN protein, or glycophorin) and contain a decreased amount of PAS2 as demonstrated by radiolabeling of surface porteins and chemical techniques. A third glycoprotein, Band 3, contains two labeled oligosaccharide chains; the more complex oligosaccharide has a higher molecular weight in En(1-) cells than in normal cells. A fourth glycoprotein, PAS3, is present in usual amounts in En(a-) cells. Cells heterozygous for En(a) are intermediate in these respects. The sialic acid is decreased in En(a-) cells, but the total carbohydrate is similar in the different membranes. The glycolipids are present in normal amounts but are much more exposed to galactose oxidase in En(a-) cells than in normal cells.