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PubMed2006

Variants of synesthesia interact in cognitive tasks: evidence for implicit associations and late connectivity in cross-talk theories.

This study examines the interaction between two types of synesthesia: ordinal linguistic personification (OLP; the involuntary association of animate qualities such as gender/personality to linguistic units such as letters/numbers/days) and grapheme-color synesthesia (the involuntary association of colors to letters and/or numbers). By examining both variants in the same individual we aim to: (a) show that features of different synesthetic variants interact in cognitive tasks, (b) provide a cognitive model of this interaction, and (c) constrain models of the underlying neurological roots of this connectivity. Studies have shown inhibition in Stroop-type tasks for naming font colors that clash with synesthetic colors (e.g. slower naming of green font for synesthetically red letters). We show that Stroop-type slow-down occurs only when incongruent colors come from other letters with matching (but not mis-matching) gender (experiment 2). We also measure the speed of OLP gender judgments (e.g. a=female; experiment 1) and show that response times are slowed by incongruent colors from other letters with mis-matching (but not matching) genders. Our studies suggest that synesthetic variants interact and that their concurrents can become implicitly connected without mediation from inducing stimuli. We interpret these findings in light of recent developmental data showing protracted heterochronous neuronal development in humans, which continues through adolescence in parietal, frontal and perisylvian areas.

Adult↗
PubMed1996

Strategies for Diagnosis of Xenotransplant-associated Retroviral Infections.

The demand for tissue for human-to-human transplantation consistently exceeds the available supply, resulting in attempts to use organs or tissues from animals; a field known as xenotransplantation. A major concern in xenotransplantation is the risk of infection of human recipients with new xenogeneic infectious agents and subsequent transmission of these infections to the general population. Of particular importance are infections with retroviruses that persist in the host and may allow silent human-to-human transmission. Pigs and baboons are considered as sources for human xenotransplants and are known to be infected with a number of retroviruses. Adequate diagnosis of pig and baboon retrovirus infections is required for pretransplant screening of animal sources to minimize risks of transmission to recipients and also for monitoring post-transplant infections in the human recipients. Strategies for serologic, molecular, and virologic diagnosis are described. Examples of virus-specific methods for detection of known retroviruses are also shown. Emphasis is made on the need for baboon and pig cell-specific polymerase chain reaction assays that are necessary for interpretation of polymerase chain reaction results of endogenous retroviruses. Generic methods for detection of novel or variant retrovirus are described and include screening by Amp-RT, an ultrasensitive reverse transcriptase assay.

Journal Article↗
PubMed2002

Segmental linkage disequilibrium within the dopamine transporter gene.

The dopamine transporter gene (DAT) has been implicated in a variety of disorders, including bipolar disorder, attention-deficit hyperactivity disorder, cocaine-induced paranoia, Tourette's syndrome, and Parkinson's disease. As no clear functional polymorphism has been identified to date, studies rely on linkage disequilibrium (LD) to assess the possible genetic contribution of DAT to the various disorders. A better understanding of the complex structure of LD across the gene is thus critical for an accurate interpretation of the results of such studies, and may facilitate the mapping of the actual functional variants. In the process of characterizing the extent of variation within the DAT gene, we have identified a number of single nucleotide polymorphisms (SNPs) suitable for LD studies, 14 of which have been analyzed, along with a 3' repeat polymorphism, in a sample of 120 parent-proband triads. Calculations of pairwise LD between the SNPs in the parental haplotypes revealed a high degree of LD (P < 0.00001) in the 5' (distal promoter through intron 6) and 3' (exon 9 through exon 15) regions of DAT. This segmental LD pattern is maintained over approximately 27 kb and 20 kb in these two regions, respectively, with very little significant LD between them, possibly due to the presence of a recombination hotspot located near the middle of the gene. These analyses of the DAT gene thus reveal a complex structure resulting from both recombination and mutation, knowledge of which may be invaluable to the design of future studies.

Dopamine Plasma Membrane Transport Proteins↗
PubMed1984

[Significance of intermittent slow waves with right posterior accentuation in the EEG's of psychiatric patients].

The study was based on the frequent occurrence of intermittent slow waves right-posterior accentuation (IRP) in the EEGs of psychiatric patients. With regard to the EEG-phenomenon we present a detailed morphological and functional description as well as an evaluation from a developmental point of view. According to case histories a clinico-psychopathological characterization of the patients with IRP is given. The IRP-phenomenon can be interpreted electrogenetically against the background of and in connection with the so-called slow alpha variant rhythms as well as the posterior slow waves characteristic of children and adolescents. These patterns have in common a certain tendency to right-sided accentuation. In accord with a hypothesis (which has been derived from other observations and considerations) of a "maturation gradient" which favours the left hemisphere, we try to explain the IRP-phenomenon as an expression of a maturation deficit. Whereas the slow alpha variant rhythms and the posterior slow waves characteristic of children and adolescents appear bilaterally for the most part, IRP by definition, limited to the right hemisphere, may be considered as a less pronounced form in comparison. Deriving from clinico-psychopathological assessment the relationships are as follows: Patients with IRP account for about 5% of the in-patients in our psychiatric hospital. The IRP phenomenon seems to be closely linked to the male sex. Although a clear relationship with nosological categories (ICD) could not be proved, it seems that patients suffering from schizophrenic psychoses (ICD No. 295) are more frequently represented among the patients with the IRP-phenomenon than others. For the group of schizophrenic patients with IRP we found in contrast to a control group of schizophrenics without IRP a tendency to earlier onset of their disease. Compared with the control group it is found that the IRP groups consists of younger patients at the time of conducting this study. The two comparative groups of schizophrenics with and without IRP can be characterized by differences in the more or less pronounced manifestation of a fairly large number of AMDP items. Whereas for the IRP group a symptom pattern emerges with a hypermotoric -expansive accentuation, the control group seems to tend more towards a syndrome with depressive shading. The slight tendencies towards increased hereditary disposition as well as towards increased perinatal complications among the schizophrenic IRP patients necessitate further studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1995

The hitchhiking effect on the site frequency spectrum of DNA polymorphisms.

The level of DNA sequence variation is reduced in regions of the Drosophila melanogaster genome where the rate of crossing over per physical distance is also reduced. This observation has been interpreted as support for the simple model of genetic hitchhiking, in which directional selection on rare variants, e.g., newly arising advantageous mutants, sweeps linked neutral alleles to fixation, thus eliminating polymorphisms near the selected site. However, the frequency spectra of segregating sites of several loci from some populations exhibiting reduced levels of nucleotide diversity and reduced numbers of segregating sites did not appear different from what would be expected under a neutral equilibrium model. Specifically, a skew toward an excess of rare sites was not observed in these samples, as measured by Tajima's D. Because this skew was predicted by a simple hitchhiking model, yet it had never been expressed quantitatively and compared directly to DNA polymorphism data, this paper investigates the hitchhiking effect on the site frequency spectrum, as measured by Tajima's D and several other statistics, using a computer simulation model based on the coalescent process and recurrent hitchhiking events. The results presented here demonstrate that under the simple hitchhiking model (1) the expected value of Tajima's D is large and negative (indicating a skew toward rare variants), (2) that Tajima's test has reasonable power to detect a skew in the frequency spectrum for parameters comparable to those from actual data sets, and (3) that the Tajima's Ds observed in several data sets are very unlikely to have been the result of simple hitchhiking. Consequently, the simple hitchhiking model is not a sufficient explanation for the DNA polymorphism at those loci exhibiting a decreased number of segregating sites yet not exhibiting a skew in the frequency spectrum.

Animals↗
PubMed1993

Detection of Plasmodium vivax by polymerase chain reaction in a field study.

Detection and typing of Plasmodium vivax by the polymerase chain reaction (PCR) was evaluated in a prospective blinded comparative field study in Thailand. PCR amplification of the circumsporozoite (CS) gene was compared with microscopy for the detection of P. vivax in blood samples from 174 Thai Rangers and 50 malaria-free Bangkok residents. For PCR analysis, filter paper specimens collected by finger prick were randomly processed and blindly interpreted for the presence of the CS gene of P. vivax. The VK210 and VK247 CS variants of P. vivax were detected by specific fluorescein or radiolabeled oligoprobes. Autoradiography with 32P-labeled probes and enhanced chemoluminescent detection with fluorescein-labeled probes identified 91% and 96%, respectively, of 119 microscopically confirmed infections; both systems detected < 100 parasites/microL. Compared with microscopy, the specificity of PCR and radiometric or enhanced chemoluminescent detection was 96% and 90%, respectively. The ease of collection and transport of filter-paper specimens combined with the sensitive and specific detection of allelic genes of P. vivax by PCR suggests that this method may prove to be a valuable tool for epidemiologic and heterogeneity studies of P. vivax.

Animals↗
PubMed2005

Bose-Einstein condensation of magnons in Cs2CuCl4.

We report on results of specific heat measurements on single crystals of the frustrated quasi-2D spin-1/2 antiferromagnet Cs2CuCl4 (T(N)=0.595 K) in external magnetic fields B<12 T and for temperatures T>30 mK. Decreasing B from high fields leads to the closure of the field-induced gap in the magnon spectrum at a critical field Bc approximately = 8.51 T and a magnetic phase transition is clearly seen below Bc. In the vicinity of Bc, the phase transition boundary is well described by the power law Tc(B) proportional, variant (Bc-B)(1/phi), with the measured critical exponent phi approximately =1.5. These findings are interpreted as a Bose-Einstein condensation of magnons.

Journal Article↗
PubMed1976

Abnormal chromosome 22 and recurrence of trisomy-22 syndrome.

Trisomy-22 was confirmed with both Q- and G-banding in two sibs. Growth and mental retardation plus various dysmorphic features of this syndrome are described and compared with previous reports. Cytogenetic studies reveal a morphologically atypical No. 22 in cells of the phenotypically normal mother (46,XX) and in both affected children. The variant G chromosome is identified as No. 22 by Q- and G-banding and is interpreted as a product of a pericentric inversion on the basis of general length, arm ratio (1.4), and anomalous satellite association frequency. Repeated nondisjunction for No. 22 is considered to have resulted from asynapsis caused by interference of an inversion loop configuration which, though short, comprised a major part of chromosome 22.

Abnormalities, Multiple↗
PubMed1991

Cocaine and chest pain: clinical features and outcome of patients hospitalized to rule out myocardial infarction.

OBJECTIVE: To investigate the clinical features, electrocardiographic findings, and hospital course in patients admitted with acute chest pain temporally related to cocaine use. DESIGN: Retrospective data analysis. SETTING: A 485-bed county hospital. PATIENTS: One hundred and one consecutive patients with cocaine-related chest pain admitted to the hospital to rule out myocardial infarction. MEASUREMENTS AND MAIN RESULTS: The quality of the chest pain frequently suggested myocardial ischemia. Dyspnea was common (56%). The onset of chest pain occurred during cocaine use in 21% of patients, within 1 hour of use in 37%, and after 1 hour of use in 42%. Admission electrocardiographic findings were interpreted as normal in 32% of patients; as acute myocardial injury in 8%; as early repolarization variant in 32%; as left ventricular hypertrophy in 16%; and as "other" in 12%. Forty-three percent of patients had ST-segment elevation meeting the electrocardiographic criteria for use of thrombolytic therapy, but such elevation was usually due to the early repolarization variant. The initial total creatine kinase was elevated more than 3.3 mu kat/L (200 U/L) in 43% of patients, and an elevated total creatine kinase was recorded at some time during the hospital course in 47% of patients. The creatine kinase MB fraction was less than 0.02 in all patients. Myocardial infarction was ruled out in all patients. No patient experienced in-hospital cardiovascular complications. CONCLUSION: The quality of acute chest pain related to cocaine use is indistinguishable from that experienced in acute myocardial ischemia. Abnormal or normal variant electrocardiographic findings are common in patients with chest pain related to cocaine use, but nevertheless the incidence of acute myocardial infarction is low. The ST-segment and T-wave changes can mimic acute myocardial injury and are most likely normal findings in young black men that can be readily recognized in the emergency department. Most of these patients do not require admission to an intensive care unit.

Adolescent↗
PubMed2003

Association of 3q21q26 syndrome with different RPN1/EVI1 fusion transcripts.

BACKGROUND AND OBJECTIVES: Patients with acute myeloblastic leukemia (AML) with features of myelodysplastic syndrome and abnormalities of megakaryocytopoiesis often have cytogenetic aberrations of 3q21 and 3q26 bands involving the paracentric inversion [inv(3) (q21q26)] or a reciprocal translocation [t(3;3) (q21;q26)]. These abnormalities frequently cause inappropriate expression of the EVI1 gene located at 3q26. Other genes that have been implicated at the rearrangement breakpoint are GR6 and RPN1 (both on 3q21). The aim of this study was to investigate the expression of the EVI1 fusion genes in AML patients with 3q21q26 syndrome. DESIGN AND METHODS: We used reverse transcription polymerase chain reaction to evaluate the expression of EVI1 and GR6, and particularly of the fusion genes RPN1-EVI1 and GR6-EVI1 in 9 AML patients with either inv(3)(q21q26) (7 cases) or t(3;3)(q21;q26) (2 cases). RESULTS: EVI1 and GR6 were always expressed, as was RPN1-EVI1; GR6-EVI1 was absent. In 8/9 patients, the part of EVI1 retained in RPN1-DEVI1 contained blocks B and C of the PR domain commonly found in the MDS1-EVI1 gene. In the remaining patient [with inv(3) (q21q26)], only block C was retained: we named this variant fusion gene RPN1-DEVI1. This patient lacked the micromegakaryocytopoiesis frequently found in 3q21q26 syndrome. INTERPRETATION AND CONCLUSIONS: These findings support the hypothesis that EVI1 activation plays a dominant role in the pathogenesis of the 3q21q26 syndrome. EVI1 expression might occur either as a consequence of rearrangements leading to the formation of different fusion transcripts, such as RPN1-EVI1 and RPN1-DEVI1 or following disruption of the PR activation domain of the MDS1-EVI1 gene.

Adult↗
PubMed2005

Chromosomal studies in infertile men with oligozoospermia & non-obstructive azoospermia.

BACKGROUND & OBJECTIVE: Chromosomal anomalies have been postulated to be as one of the principal genetic factors in male infertility. Cytogenetic evaluation of men with severely compromised semen parameters reveals an increased incidence of chromosomal aberrations when compared with the normal population. The objective of this study was to determine the chromosomal constitution and sperm characteristics among Indian males with severe male factor infertility. METHODS: In this prospective study we investigated 88 infertile men (42 men with azoospermia and 46 men with sperm count <5 x 10(6) million/ml) prior to intracytoplasmic sperm injection (ICSI) treatment. Karyoptying was performed on peripheral blood lymphocytes according to standard methods. Polymerase chain reaction (PCR) was performed to screen the microdeletions in the AZF region of the Y chromosome. RESULTS: Constitutional chromosome abnormalities were identified in 14.3 per cent of azoospermic and 6.5 per cent of oligozoospermic men, with an overall rate of 10.2 per cent. Chromosomal abnormalities included gonosomal aberrations in 5 cases. Robertsonian translocation in one, trisomy 7 mosaicism in one case, deletion in chromosome 16 in one, and a marker chromosome in one case. Chromosome variants were observed in 33 (37.5%) subjects. Yqh- was the most frequent variant in sex chromosomes and increased length in heterochromatin and satellites were observed in autosomal chromosomes. INTERPRETATION & CONCLUSION: The high rate of chromosomal anomalies among infertile men strongly suggests the need for routine cytogenetic analysis prior to employment of assisted reproduction techniques. In addition, meticulous follow-up of babies born after ICSI, especially male offsprings, is necessary.

Adult↗
PubMed1991

Structural and functional roles of highly conserved serines in human lipoprotein lipase. Evidence that serine 132 is essential for enzyme catalysis.

The structure of human lipoprotein lipase was recently deduced from its cDNA sequence. It contains 8 serine residues (residues 45, 132, 143, 172, 193, 244, 251, and 363) that are absolutely conserved in both lipoprotein lipase and hepatic lipase across all species studied. The high homology between lipoprotein lipase, hepatic lipase, and pancreatic lipase suggests that the catalytic functions of these enzymes share a common mechanism and that one of the 8 conserved serines in human lipoprotein lipase must play a catalytic role as does serine 152 in the case of pancreatic lipase (Winkler, F. K., D'Arcy, A., and Hunziker, W. Nature 343, 771-774). We expressed wild-type and site-specific mutants of human lipoprotein lipase in COS cells in vitro. We produced two to four substitution mutants involving each of the 8 serines and assayed a total of 22 mutants for both enzyme activity and the amount of immunoreactive enzyme mass produced. Immunoreactive lipase was detected in all cases. With the exception of Ser132, for each of the 8 serine mutants we studied, at least one of several mutants at each position showed detectable enzyme activity. All three substitution mutants at Ser132, Ser----Thr, Ser----Ala, and Ser----Asp, were totally inactive. Ser132 occurs in the consensus sequence Gly-Xaa-Ser-Xaa-Gly present in all serine proteinases and in human pancreatic lipase. The x-ray crystallography structure of human pancreatic lipase suggests that the analogous serine residue in human pancreatic lipase, Ser152, is the nucleophilic residue essential for catalysis. Our biochemical data strongly support the conclusion that Ser132 in human lipoprotein lipase is the crucial residue required for enzyme catalysis. The observed specific activities of the variants involving the other seven highly conserved serines in human lipoprotein lipase are consistent with the interpretation that this enzyme has a three-dimensional structure very similar to that of human pancreatic lipase.

Amino Acid Sequence↗
PubMed1989

[Clinical evaluation on the diagnosis of chest disease using CRT units].

To investigate the diagnostic efficacy of two CRT systems in pulmonary diseases, two clinical studies were performed. One of the CRTs has 1,750 x 2,000 resolution (CRT-A), and the other has 1,280 x 1,024 (CRT-B). In the first run, five conventional PA chest X-ray films in which diagnosis was already confirmed, were digitized by a 5 pixels/mm aperture with 8 bits/pixel, processed using four variant methods, and stored on a magnetic disk. These images were displayed on the CRTs and interpreted for normal structures and abnormalities by 24 chest specialists. Among the results of statistical analysis concerning image reading, it was concluded that suitable spatial frequency images using CRT-A can be used for interpretation of normal structures without clavicles and intermediate bronchial images. On the late run, four conventional chest X-ray films were digitized with 10 bits/pixel, processed for spatial frequency, and interpreted for anatomical sites and kinds of pulmonary diseases indicated by nodules, diffusion, opacity, etc., by 22 chest specialists. ROC analysis was performed with the answers of image reading. However, the results of the data analysis were not significantly different from those of conventional X-ray films.

Computer Systems↗
PubMedDate not supplied

[Surgical treatment in Poland's syndrome in children].

An experience with treatment of 16 patients with the Poland syndrome has been analyzed, 12 of them had been operated upon. An interpretation of the disease as a defect and deformity is proposed. The clinical picture of the variants of the Poland syndrome is describes. The authors give a description of the preoperative preparation, postoperative management and a technique of the operative liquidation of all the symptoms of the defect. There were no lethal outcomes. An analysis of long-term results is given.

Adolescent↗
PubMed1985

Defective adhesion to extracellular matrix leads to altered social behaviour in cultured fibroblasts.

We describe the properties of variant mouse fibroblasts selected for poor adhesion to growth substratum containing subcellular matrix accumulated by adherent cells at confluence. The variant cells adhere to virgin plastic and grow normally to confluence in the presence of serum. After subculture and reseeding onto the same surface the cells initially adhere, but after a further 2 days of growth they retract into aggregates and detach. If the aggregates are dispersed and cells reseeded onto the same surface they remain rounded. However, if the same cells are added back to virgin plastic they adhere and grow normally. The retraction can be abolished by treating the subcellular matrix-coated plastic with papain. This behaviour therefore reflects the ability of the cells to modify the composition of the underlying substratum during growth. The variant cells also exhibit retraction 2 days after seeding on a surface previously containing wild-type cells at confluence, while wild-type cells do not retract on subcellular matrix deposited by variants. This shows that the variant behaviour arises not from a deficiency in the subcellular matrix, but from an alteration in the adhesive capacity of the cells. The results are interpreted in terms of three putative adhesion mechanisms: cell-cell adhesion in confluent monolayers and aggregates; 'early' type cell-substratum adhesion, which occurs during culture on virgin plastic; and 'late' type cell-substratum adhesion occurring on surfaces containing accumulated subcellular matrix. The variant phenotype is characterized by a deficiency in the last of these. It is also associated with an increased ability to grow in suspension culture at high dilution.

Animals↗
PubMed1994

Sonography of the fetal gastrointestinal tract: anatomic variants, diagnostic pitfalls, and abnormalities.

Prenatal sonography has the potential to show a wide range of abnormalities in a fetus's gastrointestinal tract. Suspected fetal gastrointestinal abnormalities should be interpreted with caution, however, as the sonographic appearance of a healthy fetus's gastrointestinal tract is variable and there is considerable overlap in the appearances of normal and abnormal fetal bowel. Similarly, pathologic processes originating from organ systems other than the gastrointestinal tract can at times exhibit sonographic patterns remarkably similar to those of dilated bowel. This review examines the sonographic findings of gastrointestinal disorders seen in utero, emphasizing potential diagnostic pitfalls arising from confusion with normal anatomy, anatomic variants, and pathologic processes elsewhere in the fetus.

Congenital Abnormalities↗
PubMedDate not supplied

Histologic predictors of renal cell carcinoma response to interleukin-2-based therapy.

The authors examined pathology from patients with renal cancer (RCC) treated with IL-2 to determine response rates for clear cell and variant RCC and to identify histologic features that predict response. Pathology specimens were reviewed by a single pathologist who was blinded to both the prior pathology interpretation and the therapeutic response. Findings were correlated with response to IL-2 therapy. Evaluable pathology specimens were obtained from 231 patients. Of 163 primary RCCs, the response rate was 21% (30/146) for patients with clear cell versus 6% (1/17) for patients with variant or indeterminate type RCC (P = 0.20). For clear cell carcinomas, response to IL-2 was associated with the presence of alveolar features and the absence of papillary and granular features. Patients with more than 50% alveolar features and no granular or papillary features had a 39% response rate (14/36). Patients with alveolar and granular features representing less than 50% of the specimen and no papillary features had a 19% response rate (15/77). The response rate for the others was 3% (1/33). This model was then applied to an independent sample of 68 metastasis specimens. Response rates in the three prognostic groups and for patients with non-clear cell cancers were 25% (5/20), 9% (2/22), 0% (0/16), and 0% (0/10), respectively. Median survivals for all patients with clear cell tumors by risk group were 2.87, 1.36, and 0.87 years, respectively (P < 0.001). These data suggest that patients with non-clear cell RCC or with clear cell RCC with papillary, no alveolar, and/or more than 50% granular features respond poorly to IL-2 and should be considered for alternative treatments. Investigation of other tumor-related predictors of IL-2 responsiveness is warranted.

Adenocarcinoma, Clear Cell↗