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At least 1,351 records · Page 75Linked to original sources
PubMed1991

More than half the sporadic cases of hemophilia A in Sweden are due to a recent mutation.

The aim of this study was to ascertain how many of the sporadic cases of severe Haemophilia A in Sweden are due to recent mutation, and establish its origin. DNA analysis was performed in 18 randomly selected families with a sporadic case of severe haemophilia A. Restriction fragment length polymorphism (RFLP) patterns were investigated, two intragenic (Bc1 I, Xba I/Kpn I) and two extragenic (DX 13, St 14) RFLP being used. In 10/18 families a haemophilia-linked gene was found to have derived from the healthy maternal grandfather; on the basis of clotting and immunological assay results, the odds were high (greater than 104:1) for maternal carriership in four of these 10 cases, and for maternal non-carriership in two, four being indeterminate. In 4/18 families a haemophilia-linked gene derived from the healthy maternal grandmother; according to clotting and immunological assay results, in two cases the odds were high for maternal non-carriership. In the remaining 4/18 families no conclusions could be drawn from the RFLP pattern as to the origin of mutation. We conclude that at least 55% of the sporadic cases of severe hemophilia A in Sweden are due to a recent mutation within the last two generations.

Hemophilia A↗
PubMed1975

The systemic arterial pattern of the guinea pig: the abdomen.

The systemic arterial pattern of the guinea pig was studied to determine the arrangement of the major arterial trunks and their branches. Fiftynine specimens were examined by dissection, angiography or corrosion casting. The arterial arrangement was found to resemble a typical mammalian pattern, although some exceptions were noted. For example, the guinea pig usually has a single vessel, the celiacomesenteric trunk, instead of separate celiac and cranial mesenteric arteries. The celiac components of this vascular axis were found to originate in four different patterns. Also, the renal arteries were found to be single or double on either side with double origins more frequent.

Abdomen↗
PubMed1993

Change of isoenzyme pattern during long-term polyxenic cultivation of Entamoeba histolytica.

Isoenzymes of phosphoglucomutase and hexokinase were repeatedly evaluated using starch gel electrophoresis in polyxenic cultures of Entamoeba histolytica. In two out of 18 strains spontaneous changes of isoenzyme patterns were recorded. While originally they were categorized into virulent group of zymodemes, following isoenzyme analysis classified them as non-virulent. The relation between virulence and isoenzyme pattern is questionable.

Animals↗
PubMed1992

A genomic sequencing protocol that yields a positive display of 5-methylcytosine residues in individual DNA strands.

The modulation of DNA-protein interactions by methylation of protein-binding sites in DNA and the occurrence in genomic imprinting, X chromosome inactivation, and fragile X syndrome of different methylation patterns in DNA of different chromosomal origin have underlined the need to establish methylation patterns in individual strands of particular genomic sequences. We report a genomic sequencing method that provides positive identification of 5-methylcytosine residues and yields strand-specific sequences of individual molecules in genomic DNA. The method utilizes bisulfite-induced modification of genomic DNA, under conditions whereby cytosine is converted to uracil, but 5-methylcytosine remains nonreactive. The sequence under investigation is then amplified by PCR with two sets of strand-specific primers to yield a pair of fragments, one from each strand, in which all uracil and thymine residues have been amplified as thymine and only 5-methylcytosine residues have been amplified as cytosine. The PCR products can be sequenced directly to provide a strand-specific average sequence for the population of molecules or can be cloned and sequenced to provide methylation maps of single DNA molecules. We tested the method by defining the methylation status within single DNA strands of two closely spaced CpG dinucleotides in the promoter of the human kininogen gene. During the analysis, we encountered in sperm DNA an unusual methylation pattern, which suggests that the high methylation level of single-copy sequences in sperm may be locally modulated by binding of protein factors in germ-line cells.

5-Methylcytosine↗
PubMed1988

Specific lysis of allogeneic cells after activation of CD3- lymphocytes in mixed lymphocyte culture.

Human CD3- lymphocyte populations were obtained by treating peripheral blood lymphocytes with mAbs directed to CD3, CD4, and CD8 surface antigens. The resulting populations were cultured with irradiated allogeneic cells; at day 4, 100 U/ml IL-2 were added and cultures continued for an additional 10 d. The resulting populations were CD3-CD2+CD7+ and displayed cytolytic activity against PHA-induced blast cells bearing the stimulating alloantigens but not against autologous or unrelated allogeneic blast cells. When CD3- populations were cultured with irradiated autologous cells, no cytolytic activity could be detected either against autologous or allogeneic blast cells. On the other hand, K562 target cells were lysed by both MLC-derived CD3- cell populations regardless of the origin (autologous or allogeneic) of the stimulating cells. CD3- clones were further derived from MLC-stimulated CD3- populations. These clones displayed a cytolytic pattern similar to the original MLC populations as only specific PHA blasts could be lysed. These clones did not express detectable surface TCR-alpha/beta or -gamma/delta molecules and lacked productive mRNA for TCR alpha and beta chains, while small amounts of TCR-gamma mRNA were detectable in one of four clones tested. Also mRNA for CD3 gamma and delta chains were undetectable in all clones, however, CD3 epsilon mRNA was consistently present.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Evolution of influenza A virus nucleoprotein genes: implications for the origins of H1N1 human and classical swine viruses.

A phylogenetic analysis of 52 published and 37 new nucleoprotein (NP) gene sequences addressed the evolution and origin of human and swine influenza A viruses. H1N1 human and classical swine viruses (i.e., those related to Swine/Iowa/15/30) share a single common ancestor, which was estimated to have occurred in 1912 to 1913. From this common ancestor, human and classical swine virus NP genes have evolved at similar rates that are higher than in avian virus NP genes (3.31 to 3.41 versus 1.90 nucleotide changes per year). At the protein level, human virus NPs have evolved twice as fast as classical swine virus NPs (0.66 versus 0.34 amino acid change per year). Despite evidence of frequent interspecies transmission of human and classical swine viruses, our analysis indicates that these viruses have evolved independently since well before the first isolates in the early 1930s. Although our analysis cannot reveal the original host, the ancestor virus was avianlike, showing only five amino acid differences from the root of the avian virus NP lineage. The common pattern of relationship and origin for the NP and other genes of H1N1 human and classical swine viruses suggests that the common ancestor was an avian virus and not a reassortant derived from previous human or swine influenza A viruses. The new avianlike H1N1 swine viruses in Europe may provide a model for the evolution of newly introduced avian viruses into the swine host reservoir. The NPs of these viruses are evolving more rapidly than those of human or classical swine viruses (4.50 nucleotide changes and 0.74 amino acid change per year), and when these rates are applied to pre-1930s human and classical swine virus NPs, the predicted date of a common ancestor is 1918 rather than 1912 to 1913. Thus, our NP phylogeny is consistent with historical records and the proposal that a short time before 1918, a new H1N1 avianlike virus entered human or swine hosts (O. T. Gorman, R. O. Donis, Y. Kawaoka, and R. G. Webster, J. Virol. 64:4893-4902, 1990). This virus provided the ancestors of all known human influenza A virus genes, except for HA, NA, and PB1, which have since been reassorted from avian viruses. We propose that during 1918 a virulent strain of this new avianlike virus caused a severe human influenza pandemic and that the pandemic virus was introduced into North American swine populations, constituting the origin of classical swine virus.

Amino Acid Sequence↗
PubMed1987

Pluripotent steroidogenesis and ultrastructure in adrenocortical adenomas causing Cushing's syndrome.

Adrenal vein catheterization data from 2 patients with adrenocortical adenomas causing Cushing's syndrome are presented and the electron-microscopic features of one of the tumors are described. Based on the catheterization data both tumors produced all three classes of adrenal steroids (mineralocorticoids, glucocorticoids and sex steroids). Electron-microscopic examination of the tumor cells suggested an origin from the zona fasciculata. If one accepts the theory of a common cellular origin of adrenal tumors, then the pattern of steroidogenesis would indicate that the postulated original 'stem' cell retains the potential of secreting all classes of adrenocortical steroids. The clinical presentation of such tumors would thus reflect the hypersecretion of one of the steroid classes relative to the others.

Adenoma↗
PubMed1995

Circadian profile of systemic hemodynamics.

We determined the continuous 24-hour profile of mean arterial pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance in eight healthy ambulatory volunteers. Beat-to-beat intra-arterial blood pressure was recorded with the Oxford system; subjects were ambulant during daytime and slept at night. Beat-to-beat stroke volume was determined by the pulse contour method from the arterial pulse wave. During the nighttime, compared with the daytime average, there was a decrease in blood pressure (9 mm Hg), heart rate (18 beats per minute), and cardiac output (29%); stroke volume showed a small decrease (7%), and total peripheral resistance increased unexpectedly by 22%. When subjects arose in the morning a steep increase in cardiac output and decrease in total peripheral resistance were found. Comparable changes were seen during a period of supine resting in the afternoon, whereas physical exercise caused opposite changes in hemodynamics. This pattern was observed in all subjects. We conclude that the circadian pattern of cardiac output and total peripheral resistance originates from the day-night pattern in physical activity: during the nighttime, blood flow to the skeletal muscles is decreased through local autoregulation, which increases total peripheral resistance and decreases cardiac output compared with the daytime.

Adolescent↗
PubMed2005

Differentiation of mesothelioma from adenocarcinoma in serous effusions: the role of hyaluronic acid and CD44 localization.

Differentiating cells of mesothelial origin from adenocarcinoma (ACA) based on morphology alone can be a diagnostic challenge, especially in cytological specimens. Malignant mesothelioma (MM) is characterized by accumulation of abundant intracellular hyaluronic acid (HA), a feature that is not reported in ACA. The purpose of this study was to evaluate the significance of cellular HA using an HA-specific binding peptide (HABP) and the expression of its principal receptor, the standard CD44 molecule (CD44S). Archival paraffin-embedded cell blocks of serous fluids from 28 cases of reactive mesothelial cells, 14 cases of MM, 20 cases of metastatic ovarian carcinomas, 17 cases of metastatic breast carcinomas, 12 cases of metastatic lung ACA, and 12 cases of metastatic gastrointestinal ACA were stained with HA using a biotinylated HABP and CD44S. Positive staining was defined as droplet to diffuse cytoplasmic staining for HA and uniform membranous staining for CD44S. All MMs and 93% (26/28) of the benign mesothelial cells were positive for intracytoplasmic HA vs. none of ACAs. CD44S was expressed in 100% (28/28) of mesothelial hyperplesia, 86% (12/14) of MMs, 70% (14/20) of ovarian carcinomas, 29% (5/17) of breast carcinomas, 25% (3/12) of gastrointestinal ACAs, and 8% (1/12) of lung ACAs. In MM and reactive mesothelial cells, CD44S stained cell membranes diffusely with highlights on the villous surfaces and in ACA it was focal and confined to cell membranes. Immunostaining with HA is a reliable marker that can distinguish between cells of mesothelial origin (reactive mesothelial cells and MM) and ACA. The CD44S staining pattern of cells of mesothelial origin is of diagnostic significance. CD44 may prove useful in conjunction with other stains in the differential diagnosis of mesothelioma and ADA.

Adenocarcinoma↗
PubMed2005

Spatially controlled co-culture of neurons and glial cells.

The ability to create and maintain neuron and glial cell co-cultures is important for neuronal regeneration as well as for fundamental studies on neuron and glial cell interactions. We demonstrate here a method for spatially controlling the arrangement of neurons and glial cells. Line patterns of cell resistant, poly(oligoethyleneglycol methacrylate-co-methacrylic acid), was microcontact printed on various substrates to spatially control the attachment of neurons. Neuron-like cells, PC12 and SH-SY5Y cells, were confined within the unprinted line patterns and extended neurites along the line patterns. Subsequent attachment of glial cells was accomplished by converting the originally cell-resistant line patterns of poly(oligoethyleneglycol methacrylate-co-methacrylic acid) to cell adhesive by electrostatic adsorption of cationic poly-lysine, chitosan, or poly(ethyleneimine). This method for creating patterned co-cultures of neuron and glial cells provides a useful tool for investigating neuron-glial cell interactions and has potential applications in the repair or regeneration of nervous systems.

Animals↗
PubMed1996

When the brain changes its mind: interocular grouping during binocular rivalry.

The prevalent view of binocular rivalry holds that it is a competition between the two eyes mediated by reciprocal inhibition among monocular neurons. This view is largely due to the nature of conventional rivalry-inducing stimuli, which are pairs of dissimilar images with coherent patterns within each eye's image. Is it the eye of origin or the coherency of patterns that determines perceptual alternations between coherent percepts in binocular rivalry? We break the coherency of conventional stimuli and replace them by complementary patchworks of intermingled rivalrous images. Can the brain unscramble the pieces of the patchwork arriving from different eyes to obtain coherent percepts? We find that pattern coherency in itself can drive perceptual alternations, and the patchworks are reassembled into coherent forms by most observers. This result is in agreement with recent neurophysiological and psychophysical evidence demonstrating that there is more to binocular rivalry than mere eye competition.

Animals↗
PubMed1988

Geographic origin and spread of pathogenic Naegleria fowleri deduced from restriction enzyme patterns of repeated DNA.

The restriction enzyme patterns of repeated DNA from 20 Naegleria fowleri and 13 N. gruberi strains were compared. On this basis strains of N. fowleri could be easily separated from N. gruberi. Although the restriction enzyme profiles of N. fowleri strains are quite homogenous, strains originating from Europe and from Australia had slightly different patterns. Both European and Australian profiles were found in the USA. In Australia a genetic variant was detected that is the same as the N. fowleri type present in New Zealand. Profiles of strains from India were identical with those from Europe. These results give additional information on the probable origin and dispersal of N. fowleri in the world. Strains of N. gruberi exhibit much more heterogenous banding patterns. Four European N. gruberi strains were, however, nearly identical while two strains from New Zealand had only a single band difference with one restriction enzyme. One Australian strain of N. gruberi was identical to an American strain that has been in culture for almost 30 years. The presence of a virus-like particle in a sister strain of this American isolate did not affect its banding patterns. Other strains of N. gruberi from the USA had diverse restriction enzyme patterns. Adelphamoeba galeacystis has restriction enzyme profiles distinct from those of the Naegleria strains investigated. Isoenzyme analysis in agarose isoelectric focusing confirmed the existence of intraspecific differences in N. fowleri.

Animals↗
PubMed1991

[Differences in blood flow in maternal blood vessels in normal pregnancies and gestosis].

Clinical studies showed a lower blood flow in renal und uterine vessels in gestotic pregnancies. A comparison was therefore made between three maternal vessels (uterine, renal und thyroideal vessels) in normal and gestotic pregnant and non-pregnant women to show if the higher vessel resistance in gestotic pregnancies is a local or systemic event. There was a significant difference between the collectives in the blood flow of renal and uterine vessels, but no difference between the resistance in thyroideal vessels. The difference in the blood flow of renal vessels was higher than the difference in uterine vessels in the pregnant women. The increasing resistance, therefore, seems to be a local event at the beginning of the gestotic pattern of signs and symptoms. The higher resistance in the renal vessels allows, the conclusion that the kidney might be the important organ in the origin of the gestotic pattern of signs and symptoms.

Adult↗
PubMed2002

Conserved response regulator CtrA and IHF binding sites in the alpha-proteobacteria Caulobacter crescentus and Rickettsia prowazekii chromosomal replication origins.

CzcR is the Rickettsia prowazekii homolog of the Caulobacter crescentus global response regulator CtrA. CzcR expression partially compensates for developmental defects in ctrA mutant C. crescentus cells, and CzcR binds to all five CtrA binding sites in the C. crescentus replication origin. Conversely, CtrA binds to five similar sites in the putative R. prowazekii replication origin (oriRp). Also, Escherichia coli IHF protein binds over a central CtrA binding site in oriRp. Therefore, CtrA and IHF regulatory proteins have similar binding patterns in both replication origins, and we propose that CzcR is a global cell cycle regulator in R. prowazekii.

Bacterial Proteins↗
PubMed2002

Multifaceted purinergic regulation of stimulus-secretion coupling in the neurohypophysis.

The neurohypophysis is an original model of the CNS secretory system releasing vasopressin (AVP) and oxytocin (OXT), two neuropeptides hormones synthesized by the magnocellular neurons of the hypothalamus. Specific patterns of action potentials originating from cellular bodies of magnocellular neurons control the release of AVP and OT, but intra-neurohypophysis regulations do modulate the neuropeptides release. There is now good evidence for the effects of extracellular purines in the control of neurohypophysial secretion. This paper brings together evidence for the multiple, intricate actions of purines in the extracellular space of the neurohypophysis. It covers four main points. First, the activity-dependent release of endogenous ATP in the neurohypophysis. Second, the action of ATP on both neuronal and non-neuronal compartments of the neural lobe. Third, the termination of ATP positive feedback by ecto-nucleotidases. And finally the possible involvement of adenosine in the regulation of neurohypophysial secretion and glial plasticity. The data suggest that ATP and adenosine are physiological modulators of the release of neurohypophysial peptides by acting directly on nerve terminals and indirectly on neurohypophysial astrocytes. Since purinergic receptors are widespread in nervous and endocrine systems, the neurohypophysis appears as an useful model for studying the role of purines in the regulation of stimulus-secretion coupling and neuron-glia interactions. The feedback mechanisms found in the neurohypophysis could be ubiquitous, occurring throughout the central nervous system and in other secretory systems.

Animals↗
PubMed2006

Control of Hoxd genes' collinearity during early limb development.

Hoxd genes are essential for limb growth and patterning. They are activated following a complex transcriptional regulation, leading to expression domains that are collinear in both space and time. To understand the mechanism(s) underlying collinearity, we produced and analyzed a set of mouse strains containing systematic deletions and duplications within the HoxD cluster. We show that two waves of transcriptional activation, controlled by different mechanisms, generate the observed developmental expression patterns. The first wave is time-dependent, involves the action of opposite regulatory modules, and is essential for the growth and polarity of the limb up to the forearm. The second phase involves a different regulation and is required for the morphogenesis of digits. We propose that these two phases reflect the different phylogenetic histories of proximal versus distal limb structures and discuss the biological relevance of these collinear patterns, particularly for the origin of the anterior-to-posterior limb polarity.

Age Factors↗
PubMed1996

Patterns of failure following treatment of pseudomyxoma peritonei of appendiceal origin.

Pseudomyxoma peritonei is a rare disease caused by a perforated adenoma of the appendix. It results in extensive accumulation of mucinous tumour at specific locations within the abdomen and pelvis. The study was undertaken to examine patterns of recurrence in patients with grade I disease treated by cytoreductive surgery and early postoperative intraperitoneal chemotherapy. After a median follow-up of 1.9 years (range 0.5-7.4 years) 42 out of 118 patients had recurred. In 32 patients, detailed information regarding the anatomical location of recurrent tumour from CT-scan and second-look laparotomy were available and these form the basis of this study. The volume of recurrent tumour was recorded at eight abdominal sites, the laparotomy scar and at suture lines. Patient, tumour and treatment factors were analysed for possible relationship with the pattern of recurrence. With recurrence, true metastatic disease was observed in 3 patients and a distinctly higher grade of intraperitoneal tumour in another patient. Pleural spread of pseudomyxoma was found in 6 patients, always related to entering the pleural cavity during cytoreduction (P = 0.000031). Two abdominal sites consistently had an increase in tumour deposits at re-operation as compared to the initial cytoreduction. Small bowel had large deposits at re-operation in 17% versus 3% at initial cytoreduction and retroperitoneal surfaces 10% versus 0%. Recurrences were most frequent in the left subhepatic/lesser omentum area (28%), while the right subdiaphragmatic area (3%) was least involved. Pseudomyxoma peritonei recurrence in the laparotomy scar was found in 15/29 patients (52%), significantly more frequent if tumour had been present at former laparotomy scars during cytoreduction (P = 0.042). In 15/25 (60%) of patients, recurrences were found at suture lines. Differences in the completeness of cytoreduction, inadequate distribution of intraperitoneal chemotherapy to upper abdominal and small bowel surfaces, and entrapment of tumour within suture lines were thought to be causal factors consistent with this pattern of recurrence. Consequences for future treatment strategies are discussed.

Abdomen↗
PubMed1991

Classification of cell receptors.

This manuscript constitutes a first attempt to categorize the cell receptors. Based on evolutionary and biological characteristics, it is possible to classify ligand-receptor units into original families. Certain dynamic patterns that could not be classified previously lead us towards the ligand-receptor unit. Biological information is transformed at the receptor by cellular transduction and effector pathways. The dynamic code is compared with the genetic code. The dynamic code controls the biological information patterns necessary for the integral function and structure of cells, tissue, organs, and organisms. The genetic code controls the assembly and molecular structure of proteins. The original families can be assigned certain original functions. A coevolution of ligand-receptor and dynamic code is revealed. For the time being the most useful approach to receptor classification would seem to be based on the organization of the molecular and protein structure of receptors. Two classes of receptor can be described: receptors for cyclic hydrophobic compounds and membrane receptors. Until we know of the families of single membrane-spanning receptors, fourfold membrane-spanning receptors, sevenfold membrane-spanning receptors, fourfold membrane-spanning receptors. For the sevenfold membrane-spanning receptor the identity of conformation and dynamics of biological function has been established. Light and peptide ligands are used as examples. A systems theory for information transduction at receptors is introduced which can also describe the processes of sensitivity modulation.

Amino Acid Sequence↗