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PubMed1984

Advances in the dental search for Native American origins.

The Sinodont dental morphology pattern of NE Asia is today more complex and was so by 20,000 years ago, than the simplified Sundadonty of SE Asia-Oceania, and the very simplified pattern that evolved greater than 20,000 B.P. All Native Americans are Sinodonts. Intra--and inter-hemispheric statistical analyses of 28 dental traits in greater than 6000 N & S American and greater than 1100 NE Asian crania reveal three temporally stable American sub-patterns, suggesting prior evolution in Sino-Siberia. The hypothesized biocultural associations and migration episodes are: (1) "Upper Cave" Sinodonts with the generalized Chinese Microlithic Tradition reach the Arctic steppe via the Lena basin to become Paleo--and most later Indians. (2) Smaller-game-hunting Siberian Diuktaians cross to Alaska at forest-forming terminal land bridge times to become Paleo-Arctic and subsequent Na-Dene-speaking NW forest Indians. (3) Lower Amur basin-N Japan blade-makingfolk evolve a coastal culture on the way to the land bridge's SE terminus at Anangula-Umnak where the oldest skeletons of the dentally distinctive but variable Aleut-Eskimos have been found.

Americas↗
PubMed1987

Patterns of disease in localized extranodal lymphomas.

The site of origin of lymphoid tissue is an important determinant of lymphocyte migration patterns. The association of gastrointestinal (GI) and Waldeyer's ring lymphoma and the unique lymphocyte migration pattern of gut-associated lymphoid tissue (GALT) have been previously described. To establish whether predictive clinical patterns of disease occur in localized Non-Hodgkin's lymphoma, survival and relapse patterns for 496 patients with stage I and II non-Hodgkin's lymphoma (NHL) treated with loco-regional irradiation (XRT) alone were examined. We identified 139 patients with GALT lymphoma (defined as arising from primitive gut and including Waldeyers' ring, thyroid, and GI lymphomas) and 87 patients with extranodal non-gut-associated lymphoma (ENL). Survival and relapse data were assessed in multifactorial analysis to correct for previously identified other prognostic variables. GALT lymphomas (GALT-L) have a survival advantage compared with other ENL (P = .017) independent of stage and histology. A difference in distant relapse (DR) rate between GALT-L and other ENL (P = .0002) was also identified. The presentation site of localized extranodal NHL is predictive of clinical behavior and is an independent determinant of outcome. This may be an expression of lymphocytic origin and determinants of migration patterns.

Abdominal Neoplasms↗
PubMed1980

Operant control of precentral neurons: bilateral single unit conditioning.

Two Macaca mulatta monkeys were reinforced to operantly control a precentral neuron's firing pattern while a contralateral unit was monitored simultaneously. The results from 38 complete experiments indicate the following: (a) upon altering to the operant task, both the contingent and the non-contingent neurons changed firing patterns from preconditioning levels. However, as the monkey brought the contingent unit under operant control, there were no significant changes in the firing pattern of the non-contingent neuron; (b) when the contingencies were reversed so that the monkeys were reinforced to control the originally non-contingent neuron, the firing pattern off the originally contingent neuron returned to near baseline levels. These data indicate that although many precentral units may change firing patterns when the monkey attends to the operant task, the reinforced changes in firing pattern are not the result of a generalized phenomenon at the spinal level.

Animals↗
PubMed1987

Gangliosides of human melanoma: altered expression in vivo and in vitro.

The ganglioside composition of human melanoma was analyzed in five sets of tumor specimens obtained directly from surgery, from the autologous tissue culture cell lines, and from the autologous cell lines grown in athymic nude mice. Total gangliosides of these 15 melanoma specimens were isolated and purified, and the amount of each component ganglioside was analyzed by thin-layer chromatography and a thin-layer chromatography scanner. The ganglioside composition of the five surgical melanoma specimens clearly exhibited different patterns from each other. Moreover, none of the autologous cultured melanomas possessed the same ganglioside composition as their original biopsied tumors. However, when these melanoma cell lines were transplanted into nude mice, the ganglioside composition was converted back to the same ganglioside pattern as in the original surgical specimens. The results support the view that changes in the ganglioside composition of melanoma during in vitro growth are caused by the culture environment rather than by selection of melanoma cells with a particular genotype. Reestablishment of the original ganglioside patterns after passage in nude mice provides clear evidence that in vivo expression of gangliosides is a conserved and stable function specified by the human melanoma cells.

Animals↗
PubMed1988

Training and Stroop-like interference: evidence for a continuum of automaticity.

Three experiments varied the extent of practice in an analog of the Stroop color-work task. Each experiment involved four phases: (a) baseline naming of four familiar colors, (b) training in consistently naming four novel shapes by using the names of the same four colors, (c) naming the colors when they appeared in the form of the shapes, and (d) naming the shapes when they appeared in color. In Experiment 1, with up to 2 hr of training in shape naming, colors were named much faster than shapes. Interference was observed only in Phase 4. In Experiment 2, with 5 hr of training, shape naming sped up, but was still slower than color naming. Nevertheless, there was symmetrical interference in Phases 3 and 4, and this persisted 3 months later without further training. Experiment 3 replicated this pattern and then extended practice to 20 hr, by which time shape and color naming were equally rapid. After 20 hr, interference appeared only in Phase 3, reversing the original asymmetry. The overall pattern is inconsistent with a simple speed of processing account of interference. The alternative idea of a continuum of automaticity--a direct consequence of training--remains plausible, and the implications of this perspective are considered.

Attention↗
PubMed1976

Cell-to-substrate contacts in living fibroblasts: an interference reflexion study with an evaluation of the technique.

The closeness of contact between cultured chick heart fibroblasts and glass substrates has been examined by interference reflexion microscopy. Evaluation of the optical technique demonstrated that both the film of medium between the cell and substrate and the cell itself act as two superimposed thin films which generate a complex interference pattern in reflected light or low illuminating numerical aperture (I.N.A.). The interference pattern generated by the cell consists of first and higher orders of interference and can be eliminated from the image by increasing the I.N.A. to greater than 1.0. The residual zero-order interference pattern at high I.N.A. originates from the thin film of medium between cell and substrate and corresponds to the closeness of contact between cell and substrate. Based on the zero-order interference pattern and a comparison of the same cells with differential interference optics, the following features were recognized in living chick heart fibroblasts. Focal contacts, 0.25-0.5 mum wide, 2-10 mum long, separated by 10-15 nm from the substrate, are located under the peripheral regions of the leading lamellae and near the edge of extended non-spreading regions of the cell margin in moving and stationary cells. Individual focal contacts are coincident with cytoplasmic fibres of the same dimensions as the contact or with the peripheral ends of longer fibres that extend from the focal contact toward the centre of the cell. In spreading cells a second type of contact is present under the peripheral regions of the leading lamellae. This close contact consists of a broad area of uniform cell-to-substrate separation distance (ca. 30 nm). Focal contacts are distributed within the close contact under the leading lamellae. Lamellipodia extend ahead of the close contact and are separated by 100 nm or more from the substrate. Depending on the previous motile history of the cell, the close contact extends to varying degrees under the centre of the cell but it is typically dissected here by discrete areas of distinctly greater cell-to-substrate separation (100-140 nm). Evidence for the adhesive nature of the focal contacts is considered. The common identity is discussed of the focal contacts and associated cytoplasmic fibres described here in living cells with the regions of closest apposition to the substrate and associated cytoplasmic plaques and bundles of microfilaments seen in EM studies.

Cell Adhesion↗
PubMed2005

A Bayesian approach for discriminating among alternative inheritance hypotheses in plant polyploids: the allotetraploid origin of genus Borderea (Dioscoreaceae).

Polyploidy is a common phenomenon occurring in a vast number of land plants. Investigations of patterns of inheritance and the origins of plants (i.e., autopolyploidy vs. allopolyploidy) usually involve cytogenetic and molecular studies of chromosome pairing, chromosome mapping, and marker segregation analysis through experimental crosses and progeny tests. Such studies are missing for most wild species, for which artificial crosses are difficult, not feasible, or unaffordable. We report here a Bayesian method to discriminate between alternative inheritance patterns in the two extant, tetraploid species of the monocot genus Borderea (Dioscoreaceae), which does not involve progeny array tests. Our approach is based on the screening of a large number of SSR genotypes, which were obtained from successful amplifications of 17 microsatellite regions in individuals of both B. chouardii and B. pyrenaica. We tested for tetrasomic vs. disomic modes of inheritance, using the Bayes factor test. Assignment of genotypes under both alternatives could be unequivocally done for 14 and 11 of the 17 studied microsatellite regions in B. chouardii and B. pyrenaica, respectively, totaling 9502 analyzed genotypes. The comparison of posterior probabilities for the two competing hypotheses across the surveyed loci clearly favored a disomic inheritance pattern. Linkage tests indicated that none of the studied SSR loci were in linkage disequilibrium, thus representing independent samples of the Borderea genome. These results, along with previous allozyme data, support the allotetraploid origin of this paleoendemic genus and reveal the lowest reported chromosome base number for the family of the yams.

Bayes Theorem↗
PubMed2004

Anatomical variations of the splenic artery and its clinical implications.

The variations in orgin, course, and terminal branching pattern of the splenic artery were studied in 320 cadavers. The artery originated from the coeliac trunk in the majority of cadavers (90.6%), followed by abdominal aorta (8.1%), and other sights (1.3%). A suprapancreatic course of the artery was commonly observed (74.1%) followed by enteropancreatic (18.5%), intrapancreatic (4.6%), and retropancreatic (2.8%) courses. In two cases (0.63%) the proximal part of the splenic artery made a loop that was embedded in the substance of the pancreas, which is an interesting and rare finding. In five cases (1.5%) the proximal part of the artery divided into two or more branches that had suprapancreatic and enteropancreatic courses. The splenic artery divided into terminal branches in 311 (97%) cadavers. In nine (2.8%) cadavers it passed through the hilum of spleen without dividing. Two terminal branches were the most common (63.1%) followed by four (18.8%), six (9.7%), and more than six (5.6%) branches. The present study clearly indicates that there is variation in origin, course, and terminal distribution pattern of the splenic artery. The knowledge of these variations are of significant importance during surgical and radiological procedure of upper abdominal region to avoid any catastrophic complications.

Aorta, Abdominal↗
PubMed1988

Sequential development of connections between striate and extrastriate visual cortical areas in the rat.

In these experiments we have asked whether the projection from the rat's primary visual cortex, area 17, to the extrastriate visual cortical area 18a is formed in a sequence and whether that sequence resembles the pattern of inside-out cortical neurogenesis. For this purpose fluorescent retrograde tracers were injected into area 18a at different postnatal ages (P1, P5, adult). Animals survived until 3-4 weeks of age, after migration is complete and neurons have arrived at their final laminar location. In the ipsilateral cortex, P1 injections retrogradely labeled cells in layers 5 and 6 of area 17. Labeling after P5 injections extended into more superficial layers and included the bottom of layer 2/3 and layers 4-6. After P5, more labeled cells were found at the top of layer 2/3, producing the adult laminar pattern, where the projection originates predominantly from layer 2/3. A similar sequence of laminar labeling was observed in the transcallosal connection of area 18a. This sequence of labeling, deep layers before superficial, resembles the pattern in which cortical neurons are born and indicates that axons arrive at their cortical targets in the order the cells were generated.

Animals↗
PubMed2007

Examination of the known-groups validity of the Liebowitz Social Anxiety Scale.

We examined the known-groups validity of the Liebowitz Social Anxiety Scale (LSAS) by comparing the scores of patients with social anxiety disorder (n=46), generalized anxiety disorder plus an additional diagnosis of social anxiety disorder (n=15), generalized anxiety disorder without social anxiety disorder (n=12), and nonanxious controls (n=34). The LSAS total score discriminated significantly among all pairs of groups. Similar analyses were conducted on the original LSAS subscales and additional subscales derived from the factor-analytic work of Safren et al. [1999]. Original subscales showed a pattern substantially similar to that of the total score, but subscale intercorrelations and total score-subscale correlations were extremely high, suggesting that these subscales do not provide much unique information beyond that provided by the total score. Factor-analytically derived subscales were less highly correlated with each other or with the LSAS total score. Although the pattern of differences was more variable across subscales, the factor-analytically derived subscales, in conjunction with the total score, may provide more nonredundant information of clinical relevance than the original subscales. Limitations and future directions for research on the LSAS are discussed.

Adolescent↗
PubMed2002

Slow rhythmic oscillations in intracranial CSF and blood flow: registered by MRI.

Since Lundberg first described slow oscillations as so called B-waves during ICP-monitoring, similar oscillations have been found in various physiological systems. Thus, the detection of slow waves in intracranial CSF- and blood-flow with MR-techniques seemed very likely. We examined the interventricular CSF-flow and cerebral blood flow of 11 healthy volunteers with dynamic echo-planar imaging by simultaneous registration of respiration and peripheral pulse. The spectral analysis was restricted to slow waves, which were divided into B-waves (0.008-0.05 Hz), Mayer- or C-waves (0.05-0.15 Hz) and respiration-related waves (0.15-0.6 Hz). In the CSF, the integrated amplitude of B-waves accounted for 18.2%, Mayer- or C-waves for 26.9% and respiration-related waves for 55.0%. Proportional values were recorded in the artery and peripheral pulse. In the venous sinus, a higher percentage of B- and Mayer-/C-waves and a lower percentage of respiration related waves were found. In conclusion, with MR-EPI technique, slow rhythmic oscillations in the cerebral blood- and CSF-flow can be analysed non-invasively and independently from the cardiac cycle. The comparable distribution of slow waves in the pulse, arteries and CSF may reflect an origin in autoregulation, whereas divergent patterns like in the incompressible venous sinus may be of a passive origin.

Adolescent↗
PubMed1996

Patterns of perinasal fluid flow and contractions of the diaphragm in the human fetus.

Our aim was to identify patterns of fetal perinasal fluid flow, and to determine the relationship of pattern of flow to the diaphragmatic component of fetal breathing movements. Twenty-four fetuses were studied with the use of two ultrasound systems simultaneously. Continuous video-tape records of the color and spectral Doppler imaging of fluid flow velocity in the nose and of the movements of the fetal diaphragm were made on two video recorders during 30-min study sessions. Two different patterns of fetal perinasal flow were recognized. One type had a rapid rate and low amplitude, and was independent of ultrasonographically observed movements of the fetal diaphragm. The other type had a lower rate and higher amplitude, and was uniformly related to diaphragmatic contractions. The breath-to-breath interval, time of inspiration, time of expiration and peak inspiratory and expiratory velocities were determined for each type of perinasal flow. Two ratios were used to quantify the change of peak flow velocity. There were significant differences in the values of all timing parameters between diaphragm-related perinasal flow velocities and those not related to the diaphragm, at both 30-36 and 37-41 weeks of gestation. The rate of perinasal flow related to diaphragmatic contraction cycles was one-third that of the flow cycles not related to diaphragmatic contraction (approximately 50 vs. 148 cycles/min). For both patterns of perinasal flow velocity, the expiratory peak velocity ratio was about 1.6 times higher than the inspiratory peak velocity ratio. We conclude that, in uncomplicated pregnancy, one pattern of fetal perinasal fluid flow reflects activity of the diaphragm. We speculate that the contractions of the fetal airway smooth muscle or oropharyngeal-laryngeal muscle groups are the origin of the second pattern of perinasal flow.

Blood Flow Velocity↗
PubMed1978

R-factor involvement in a local outbreak of ampicillin-resistant Haemophilus influenzae infections.

In a Swedish nursery 11 of 15 children harboured non-encapsulated Haemophilus influenzae in their nasopharynx. Six children had ampicillin-resistant and beta-lactamase-producing isolates. Five of these children had otitis whereas one was healthy. In order to identify the origin of the H. influenzae isolates their O-antigen determinants were studied by an immunodiffusion technique. 18 different rabbit antisera were used. For each isolate an O-antigen pattern was recorded. Five of the 6 resistant isolates had the same O-antigen pattern, indicating that their origin was one strain. The 6th isolate was from another strain. Different isolates from the same strain were found to be either sensitive or resistant to ampicillin. In one child the H. influenzae lost its resistance during trimethoprim-sulphamethoxazole treatment. It is concluded that an R-factor may have been involved in the distribution of ampicillin resistance in the H. influenzae studied. Previous in-vitro studies have shown that beta-lactamase production can be transmitted by a plasmid among H. influenzae strains.

Adolescent↗
PubMed1995

Spontaneous melanoma formation in nonhybrid Xiphophorus.

Melanoma in hybrids of Xiphophorus is due to the unrestricted activity of a cellular oncogene locus, Tu, encoding the growth factor receptor gene Xmrk. In nonhybrid parental fish, Tu is controlled by a tumor suppressor gene. Thus, its restricted activity leads there only to a nonmalignant, species- and population-specific macromelanophore spot pattern. Prompted by enigmatic reports on nonhybrid Xiphophorus with pigmentation abnormalities resembling melanoma, we have studied pigmentation in descendants of wild-caught fish and purebred laboratory stocks derived from wild populations. Whereas most stocks exhibiting macromelanophore patterns never developed pigmentation abnormalities, an exceptional situation for some nonhybrids was found. In X. variatus carrying the macromelanophore pattern "punctatus-2" and in X. cortezi with "spotted caudal," expressivity of the pigmentation gene ranges from a few black spots to extreme melanosis and eventually to malignant melanoma. In X. maculatus with the mutant pigmentation gene striped" carrying in addition the micromelanophore pattern "anal fin black" or "lower comet," testosterone-dependent melanoma develop originating from the corresponding micromelanophore pattern. The tumors are highly malignant and express a melanoma-associated antigen. Overexpression of the Xmrk oncogene appears as the underlying molecular mechanism for tumor induction. These findings clearly demonstrate that tumors can also develop in purebred wild-type fish. The classical model for formation of hereditary melanoma in Xiphophorus hybrids does not explain the development of melanoma in the absence of hybridization. However, their existence gives additional support to the reasoning that the Xmrk oncogene associated with the macromelanophore locus is potentially injurious.

Animals↗
PubMed1990

Specificity of initial axonal projections to embryonic chick wing.

Anterograde transport of HRP was used to map initial segmental projection patterns of motor and sensory axons to the chick embryo wing. At the earliest stages of innervation, before the peripheral nerves had formed, motor axons were distributed as two loosely organized sheets, one directed towards the dorsal muscle mass and the other to the ventral. Labeled axons emerging from a given spinal cord segment were distributed within the sheets in a pattern that reflected the origin of the axons along the rostro-caudal axis of the lateral motor column. The segmental specificity of the motor projections was analyzed again after the axonal sheets had formed recognizable nerve trunks and muscle nerves. As was observed at the younger stages, axons were distributed in a pattern that was correlated with both the relative antero-posterior (A/P) and proximo-distal (P/D) position of the forming nerve, with cranial spinal nerves projecting to anterior and proximal limb regions. Whereas most axons emerging from a given ventral root projected in accord with what would be expected from the known adult motor pool maps, segmentally unexpected projections were frequently observed. The proportion of aberrantly projecting axons appears to be quite small, and in most embryos, it was impossible to determine whether the erroneous projections originated from unbranched axons or were collateral branches of others. The findings indicate that the initial projections of motor axons to the developing wing are patterned along the A/P axis of the wing and are largely accurate; however, the guidance processes are not sufficiently precise to exclude fibers entirely from inappropriate nerves. It is likely that later developmental processes act to fine-tune the initial projection pattern.

Animals↗
PubMed1990

Developmental expression of regionally specific cell surface antigens in the Xenopus gastrula.

Molecular markers for specific cell lineages would be useful in studies of cellular differentiation. To isolate such markers monoclonal antibodies (MoABs) were raised against plasma membranes isolated from gastrulating Xenopus embryos. Those antibodies that recognized subsets of cells within the embryo were selected by indirect immunofluorescence. The analysis of eight such MoAbs is presented. Western blot analysis showed that all but one MoAb recognized a complex pattern of glycoconjugates associated with glycoproteins. All the antigens recognized by the MoAbs were maternal in origin and displayed similar spatial patterns of pregastrular expression. This pattern of immunoreactivity at the apical surface was inherited passively during cleavage by the resulting superficial blastomeres suggesting that ectodermal specific markers of maternal origin are pre-localized to the cortical ooplasm in mature oocytes. We suggest that these maternal components may be specific glycosyl transferases. Three different patterns of expression were observed during gastrulation as exemplified by MoAbs 1F10C1, 3A4D1, and 6F10B6. MoAb 6F10B6 was specific for both neural and non-neural epithelium. MoAb 3A4D1 was specific for non-neural epidermis. MoAb 1F10C1 appeared to recognize a protein epitope on an extracellular component expressed by the superficial and involuting epithelial cells. The pattern of expression for the 1F10C1 antigen suggests that it may play a role in facilitating the movement of the involuting cells during gastrulation.

Animals↗
PubMed1999

DNA methylation at mammalian replication origins.

In Escherichia coli, DNA methylation regulates both origin usage and the time required to reassemble prereplication complexes at replication origins. In mammals, at least three replication origins are associated with a high density cluster of methylated CpG dinucleotides, and others whose methylation status has not yet been characterized have the potential to exhibit a similar DNA methylation pattern. One of these origins is found within the approximately 2-kilobase pair region upstream of the human c-myc gene that contains 86 CpGs. Application of the bisulfite method for detecting 5-methylcytosines at specific DNA sequences revealed that this region was not methylated in either total genomic DNA or newly synthesized DNA. Therefore, DNA methylation is not a universal component of mammalian replication origins. To determine whether or not DNA methylation plays a role in regulating the activity of origins that are methylated, the rate of remethylation and the effect of hypomethylation were determined at origin beta (ori-beta), downstream of the hamster DHFR gene. Remethylation at ori-beta did not begin until approximately 500 base pairs of DNA was synthesized, but it was then completed by the time that 4 kilobase pairs of DNA was synthesized (<3 min after release into S phase). Thus, DNA methylation cannot play a significant role in regulating reassembly of prereplication complexes in mammalian cells, as it does in E. coli. To determine whether or not DNA methylation plays any role in origin activity, hypomethylated hamster cells were examined for ori-beta activity. Cells that were >50% reduced in methylation at ori-beta no longer selectively activated ori-beta. Therefore, at some loci, DNA methylation either directly or indirectly determines where replication begins.

Animals↗
PubMed2004

Phage types, ribotypes and tetracycline resistance genes of Salmonella enterica subsp. enterica serovar Typhimurium strains isolated from different origins in Italy.

The tetracycline resistance (tet) gene patterns of 52 tetracycline resistant Salmonella enterica subsp. enterica (S.) serovar Typhimurium isolates collected from animals, food of animal origin, and humans in Italy, were investigated to evaluate whether the tet gene patterns could be used for strain differentiation in addition to phage typing and ribotyping. The detection of tet genes was performed by specific PCR assays. Ribotyping was performed automatically using PvuII as restriction enzyme. Ten different ribotyping patterns were detected. All isolates were positive for at least one of the tet genes studied and six different tet gene patterns were observed. Ribotyping and tet gene patterns showed discriminatory indices of 0.741 and 0.812, respectively. Multiple tet genes were commonly found among tetracycline resistant S. typhimurium isolates from various sources. The resulting tet gene patterns allowed further discrimination of strains which were otherwise indistinguishable by their phage type, ribotype and origin. Thus, the analysis of tet gene patterns might represent an additional tool for the differentiation of S. typhimurium isolates.

Animals↗