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At least 775 records · Page 43Linked to original sources
PubMed1998

A statistical study of the branching of the human internal iliac artery.

This study is based on the dissections of 645 pelvic halves of Japanese cadavers. The branching of the internal iliac artery was classified according to Adachi's classification (1928), and the data was compared with previous reports. Type I was predominant in this, as well as, in previous studies. During the course of the present study, some branching forms were different from the types in Adachi's classification. Therefore, this classification was modified into 5 types and 19 groups. Type I-Group 1 was most frequently observed in the modified Adachi's classification, however, the frequency was less than 50% (46.8%). To clarify the basic branching pattern of the original internal iliac artery and to simplify the classification for medical purposes, a new classification system was designed. The superior gluteal, inferior gluteal and internal pudendal arteries were defined as the major branches of the internal iliac artery, and the umbilical artery was excluded from this group. The branching of the internal iliac artery was classified into 4 groups. Almost 80% of the present specimens were included in Group A of the new classification, namely, the internal iliac artery dividing into two major branches, the superior gluteal artery and the common trunk of the inferior gluteal and internal pudendal arteries. This type of branching seemed to be the basic branching pattern for the original internal iliac artery.

Female↗
PubMed1994

Phylogenetic pattern and the quantification of organismal biodiversity.

Biodiversity can be explored at a number of different levels and in principle may be separately quantified at each. Phylogenetic pattern has the potential to quantify and estimate biodiversity at the finest scale, that is, variation among species in features or attributes. This scale is an important one for conservation, as it should form the basis for prioritizing conservation efforts at the species level. Further, recent published objections to differentially weighting species are answered by defining option value at this feature-level. Unfortunately, there has been no consensus on exactly how phylogeny can be used to value species, possibly because proper consideration of the link between pattern and underlying features generally has been unresolved. 'Phylogenetic diversity' (PD) represents just one of several approaches that do consider diversity at the feature-level explicitly. These alternative approaches are discussed in the context of a general framework for using pattern to quantify diversity at a level below that of the original objects. The pattern framework highlights that estimation of biodiversity at a lower level using pattern will require decisions about the nature of the units of diversity, the kind of pattern to be used, the model relating unit items to pattern, and finally how this implies a pattern-based measure reflecting biodiversity. An alternative published model for relating features to a particular form of phylogenetic pattern is considered, and shown to make unwarranted assumptions. A possible alternative definition of the underlying units of diversity is examined, which may represent a different form of option value, also quantifiable using phylogeny. A possible alternative pattern to a phylogenetic tree for the prediction of feature diversity is also discussed. The appeal of these alternative approaches depends on the goals of conservation; in addition, justification for prioritizing or weighting requires that any practical approach avoid arbitrary, unwarranted, assumptions.

Animals↗
PubMed1995

[Lactate dehydrogenase (LDH)].

The quantitative distribution of the lactate dehydrogenase (LDH) isozymes is different and characteristic. Therefore, when the LDH isozymes are released from tissue to serum, as on cell injury, the serum LDH isozyme pattern changes and in a sense resembling the profile of the affected tissue. However, the serum LDH isozyme pattern often differs from the isozyme pattern in the original tissues because of differing individual isozyme elimination rates. On the contrary, we should be able to determine the origin of enzyme release, disease stage and prognosis. The LDH isozyme pattern is sometimes modified by various factors, such as LDH-immunoglobulin complex or genetic variants. Results of isozyme determinations must therefore be carefully interpreted with a knowledge of biochemistry, physiology and limitation.

Clinical Enzyme Tests↗
PubMed1995

Repeating patterns of motoneurons in nematodes: the origin of segmentation?

Evolutionarily diverse groups of animals share numerous similarities as individual neurons are assembled into functional neural circuits. One example is the hierarchical sequence of events that individual nerve cells follow during morphological development. In the initial step a presumptive neuron is generated and positioned appropriately. Second, the undifferentiated cell elaborates a growth cone capable of interacting with extrinsic cues and leading the presumptive axonal process as it is guided into areas where potential synaptic targets reside. Finally, the differentiating nerve cell selects among appropriate and inappropriate target cells as it completes the process of selective synaptogenesis. The extracellular matrix molecule laminin provides a second example, this time at the molecular level. Biochemical and genetic studies have shown that this molecule directs process guidance of neurons in vertebrates, annelids, and nematodes. In both examples an interest in neural development has provided a window through which evolutionarily processes have been revealed. The free-living soil nematode Caenorhabditis elegans possesses several features that collectively place it in a rather unique position among metazoans and has allowed genetic and cellular studies to be integrated at the level of identified neurons and neural circuits. This review will focus on developmental studies of C. elegans locomotory neural circuits. General issues that will be addressed are the similarities and differences among different taxa regarding: the relationship between cell lineage and cell fate determination in generating reiterative neural patterns; pioneer cells and the molecular basis for process guidance and finally genetic epigenetic events involved in sculpting highly specific synaptic patterns.

Animals↗
PubMed1999

Discrimination of herbal medicines according to geographical origin with near infrared reflectance spectroscopy and pattern recognition techniques.

Herbal medicines have an important role in clinical therapy in Asian countries such as Korea, Japan, and China. The objective of this study is to develop a nondestructive and accurate analytical method to discriminate herbal medicines according to geographical origin. Even though they are the same species, their qualities are different by growing conditions such as climate and soil. Near infrared (NIR) reflectance spectroscopy and a pattern recognition technique were applied for discrimination of herbal medicines according to geographical origin (Korea and China). Astragali Radix (AR), Ganoderma, and Smilacis Rhizoma (SR) were examined. It is shown that the representative NIR reflectance spectra in each group are different according to geographical origin after second derivatization to enhance spectral features. Also, the NIR reflectance spectra of Chinese and Korean samples were differentiated using principal component (PC) score plots. To establish the discrimination rule, Mahalanobis distance and discriminant analysis with PLS2 were utilized.

Astragalus propinquus↗
PubMed1990

Spontaneous discharge of afferents in a neuroma reflects original receptor tuning.

Injured afferent axons trapped in chronic nerve-end neuromas frequently generate spontaneous discharge. We asked whether the patterns of discharge originating at such sites of ectopic electrogenesis bear a consistent relationship to the patterns of discharge characteristic of the corresponding intact afferent types before injury. Nerve-end neuromas were created in electrosensory lateral line nerves in 3 species of weakly electric Gymnotiform fish. Species were chosen in which normal afferent activity occurs at highly characteristic, non-overlapping, species-specific frequencies. Afferent impulse discharge was recorded in vivo from lateral line nerve end neuromas using the nerve-teasing technique. The distribution of firing frequencies of spontaneously active neuroma afferents was relatively uniform within a given fish species, and differed significantly from species to species. Mean values were somewhat lower than for corresponding intact afferents, but the rank order of frequencies across the species was preserved. These data indicate that differential membrane remodelling after axotomy tends to reestablish normal afferent fiber tuning despite failure of regeneration, and in the absence of peripheral electroreceptor reinnervation.

Action Potentials↗
PubMed1986

Coronary arteries in complete transposition: the significance of the sinus node artery.

Hearts from 29 children with complete transposition were examined postmortem to analyze the pattern of the coronary arteries and the origin of the sinus node artery. Four patterns of origin and distribution of the coronary arteries were found. In all, the coronary arteries arose from one or both of the facing sinuses, which were termed sinus 1 and sinus 2. The patterns were left coronary artery from sinus 1 and right coronary artery from sinus 2; anterior descending artery from sinus 1 and right coronary artery and circumflex artery from sinus 2; left coronary and right coronary from sinus 2; and circumflex artery from sinus 2 and right coronary artery from sinus 1. This study highlights the patterns of the coronary arteries in complete transposition and categorizes the variability using a simple classification. It also emphasizes the surgical significance of variations in distribution of the sinus node artery.

Autopsy↗
PubMed2001

High bifurcation of common carotid artery, anomalous origin of ascending pharyngeal artery and anomalous branching pattern of external carotid artery.

We present a rare case of combined high bifurcation of the common carotid artery, anomalous origin of the ascending pharyngeal artery and unusual branching pattern of the external carotid artery. The right common carotid artery bifurcated at the level between the second and the third cervical vertebrae, giving rise to the ascending pharyngeal artery just below the bifurcation. The right external carotid artery branched directly at its origin into the superior thyroid, lingual and occipital arteries and the distal part of the external carotid artery. The latter gave rise to the right facial artery and finally bifurcated into the maxillary and superficial temporal arteries. The right posterior auricular artery arose from the right occipital artery. The finding was unilateral and other vascular anomalies were not observed. The embryogenesis of such a combination of anomalies is not clear, but the anatomic consequences may have important clinical implications.

Aged↗
PubMed2005

Fine-needle aspiration cytology of metastatic nasopharyngeal carcinoma.

Cytological features of nasopharyngeal carcinoma (NPC) were reviewed in an attempt to select cytological criteria that permit a specific recognition of metastases. For this purpose, 54 fine-needle aspiration (FNA) procedures from 43 patients with NPC were analyzed. Thirty-two (59.3%) procedures were performed before the histological diagnosis. In 25 (46.3%) procedures, smears showed many neoplastic single cells, clusters, and abundant lymphoid cells (mixed pattern). A dissociated (single cell) pattern consisting of individual neoplastic and lymphoid cells was seen in 18 (33.3%) cases. Finally, 11 (20.4%) cases showed cohesive epithelial clusters (cohesive pattern) without relevant cellular dissociation or lymphoid cells. Squamous-cell differentiation was seen in three of these cases. Most single neoplastic cells presented as large, pleomorphic naked nuclei. Other interesting findings were granulomas (n = 3), prominent eosinophilic infiltrates (n = 4), and suppurative changes (n = 5). In most smears with mixed and dissociated patterns, a nasopharyngeal origin could be suggested. On the contrary, those smears with a cohesive pattern were indistinguishable from other head and neck carcinomas. The presence (on cervical lymph nodes) of a dissociated or mixed (single cells and groups) architectural pattern of large, anaplastic cells and naked nuclei accompanied by an abundant lymphoid component is highly suggestive of undifferentiated NPC. Cytology offers a rapid diagnosis, establishes the necessity of a complete cavum examination, and helps in avoiding unnecessary and harmful biopsies.

Adolescent↗
PubMed2005

A comparison of imputation methods in a longitudinal randomized clinical trial.

It is common for longitudinal clinical trials to face problems of item non-response, unit non-response, and drop-out. In this paper, we compare two alternative methods of handling multivariate incomplete data across a baseline assessment and three follow-up time points in a multi-centre randomized controlled trial of a disease management programme for late-life depression. One approach combines hot-deck (HD) multiple imputation using a predictive mean matching method for item non-response and the approximate Bayesian bootstrap for unit non-response. A second method is based on a multivariate normal (MVN) model using PROC MI in SAS software V8.2. These two methods are contrasted with a last observation carried forward (LOCF) technique and available-case (AC) analysis in a simulation study where replicate analyses are performed on subsets of the originally complete cases. Missing-data patterns were simulated to be consistent with missing-data patterns found in the originally incomplete cases, and observed complete data means were taken to be the targets of estimation. Not surprisingly, the LOCF and AC methods had poor coverage properties for many of the variables evaluated. Multiple imputation under the MVN model performed well for most variables but produced less than nominal coverage for variables with highly skewed distributions. The HD method consistently produced close to nominal coverage, with interval widths that were roughly 7 per cent larger on average than those produced from the MVN model.

Aged↗
PubMed1998

Origin and roles of genomic methylation patterns in male germ cells.

The epigenetic modification of DNA by methylation at cytosine residues is initiated in the germ line and is required for normal embryonic development in mammals. Marked differences in genomic methylation between male and female gametes arise during gametogenesis and have been implicated in genomic imprinting. While DNA methylation patterns for different types of gene sequences are known to change during spermatogenesis, the precise role(s) of DNA methylation in the normal development of male germ cells is poorly understood. The expression of the one known active form of DNA methyltransferase is highly regulated during spermatogenesis and may provide insight into mechanisms underlying the establishment of methylation patterns in germ cells.

Animals↗
PubMed1995

A minimal, compartmental model for a dendritic origin of bistability of motoneuron firing patterns.

Various nonlinear regenerative responses, including plateau potentials and bistable repetitive firing modes, have been observed in motoneurons under certain conditions. Our simulation results support the hypothesis that these responses are due to plateau-generating currents in the dendrites, consistent with a major role for a noninactivating calcium L-type current as suggested by experiments. Bistability as observed in the soma of low- and higher-frequency spiking or, under TTX, of near resting and depolarized plateau potentials, occurs because the dendrites can be in a near resting or depolarized stable steady state. We formulate and study a two-compartment minimal model of a motoneuron that segregates currents for fast spiking into a soma-like compartment and currents responsible for plateau potentials into a dendrite-like compartment. Current flows between compartments through a coupling conductance, mimicking electrotonic spread. We use bifurcation techniques to illuminate how the coupling strength affects somatic behavior. We look closely at the case of weak coupling strength to gain insight into the development of bistable patterns. Robust somatic bistability depends on the electrical separation since it occurs only for weak to moderate coupling conductance. We also illustrate that hysteresis of the two spiking states is a natural consequence of the plateau behavior in the dendrite compartment.

Animals↗
PubMed1979

Genome analysis of Amphioxus and speculation as to the origin of contrasting vertebrate genome organization patterns.

1. The genome of Amphioxus was investigated by DNA reassociation techniques for the amount of repetitive and non-repetitive sequences and its pattern of organization. 2. A comparison of the amount of non-repetitive DNA between Amphioxus and the tunicate Ciona intestinalis does not support the hypothesis that the Cephalochordates have arisen from the Tunicates by polyploidy. 3. In the Amphioxus genome repetitive and non-repetitive elements are predominantly arranged in a short period interspersion pattern. Conclusions are presented as to the evolution of contrasting genome organization patterns among vertebrates.

Animals↗
PubMed1985

Origins of eighth nerve unit response pattern in round window cap recordings.

An experimental technique based on a combined electrical and acoustical stimulation of the cochlea (R. Charlet de Sauvage et al., 1983, J. Acoust. Soc. Am. 73, 616-627) allowing to record a close estimation of single unit contribution to the VIIIth nerve CAP has been recently proposed. D.C. Teas et al.'s (1962, J. Acoust. Soc. Am. 24, 1431-1459) theory about this pattern is that, due to conduction time in the internal auditory meatus, the propagated depolarisation partly differentiates in far-field recordings, giving rise to a specifically diphasic pattern. In order to evaluate Teas's hypothesis, 83 unit waveforms collected in 10 guinea pigs are analysed. Several reproducible peaks are identified. Latency and slope measurements are performed on these peaks. This data is processed, after identifying two homologous components which could combine in accordance with Teas's theory. The schematic pattern of a primary waveform is actually determined. Its relative amplitude on the two electrodes and the delay in the meatus are inferred. Results are in good agreement with published data. This is taken as an indirect validation of Teas's hypothesis.

Acoustic Stimulation↗
PubMed2006

The molecular origins of species-specific facial pattern.

The prevailing approach within the field of craniofacial development is focused on finding a balance between tissues (e.g., facial epithelia, neuroectoderm, and neural crest) and molecules (e.g., bone morphogenetic proteins, fibroblast growth factors, Wnts) that play a role in sculpting the face. We are rapidly learning that neither these tissues nor molecular signals are able to act in isolation; in fact, molecular cues are constantly reciprocating signals between the epithelia and the neural crest in order to pattern and mold facial structures. More recently, it has been proposed that this crosstalk is often mediated and organized by discrete organizing centers within the tissues that are able to act as a self-contained unit of developmental potential (e.g., the rhombomere and perhaps the ectomere). Whatever the molecules are and however they are interpreted by these tissues, it appears that there is a remarkably conserved mechanism for setting up the initial organization of the facial prominences between species. Regardless of species, all vertebrates appear to have the same basic bauplan. However, sometime during mid-gestation, the vertebrate face begins to exhibit species-specific variations, in large part due to differences in the rates of growth and differentiation of cells comprising the facial prominences. How do these differences arise? Are they due to late changes in molecular signaling within the facial prominences themselves? Or are these late changes a reflection of earlier, more subtle alterations in boundaries and fields that are established at the earliest stages of head formation? We do not have clear answers to these questions yet, but in this chapter we present new studies that shed light on this age-old question. This chapter aims to present the known signals, both on a molecular and cellular level, responsible for craniofacial development while bringing to light the events that may serve to create difference in facial morphology seen from species to species.

Animals↗
PubMed2002

Pulsed field gel electrophoresis for animal Salmonella enterica serovar Typhimurium isolates in Taiwan.

Salmonella enterica subspecies enterica serovar Typhimurium is a common pathogen for humans and animals. In order to trace the clonal relationship and to find the circulating strains between human and animal isolates, chromosomal DNAs from 87 serovar Typhimurium strains isolated from animals (pigs were the majority) were subjected to XbaI and SpeI digestion and pulsed field gel electrophoresis (PFGE). For the 87 animal isolates, 38 PFGE pattern combinations were obtained. As the subtyping results from animal isolates were compared with those from the 45 human isolates, it was found that 14 of the animal isolates and 13 of the human isolates shared a common PFGE pattern combination, i.e., pattern XgSf (or called X5S4). When these human and animal isolates were subjected to antibiotic susceptibility test using 11 antibiotics, it was found that strains of pattern XgSf (X5S4) belong to a common antibiogram pattern which is tetracycline, gentamicin, ampicillin, streptomycin and chloramphenicol resistant. Since most of the animal and human strains in pattern XgSf were originally isolated from various areas over different years, strains of this PFGE pattern may be the most epidemic strains which circulating between human and animal sources.

Animals↗