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PubMed2006

Anatomical study of the human omohyoid muscle: regarding intermediate morphologies between normal and anomalous morphologies of the superior belly.

Intermediate morphologies between normal and anomalous morphologies of the superior belly of the omohyoid muscle (Om) were macroscopically and stereomicroscopically observed in 34 cadavers (24 males and 10 females aged between 51 and 97 years; average age 71.0 years) for anatomical practice, which had been preserved in the Department of Morphological Biology, Ohu University School of Dentistry. The intermediate morphologies were classified into four types on the basis of the developmental degree of the muscle fibers and the number and origin of the belly as follows: type 1, the anterior margin of the belly was unclear owing to poor myofiber development; type 2, the superior belly was composed of a posterior large belly and an anterior small belly; type 3, composed of three to five bellies, with the bellies arranged in a roof tile-like morphology; and type 4, the belly was composed of two bellies arranged anterior-posteriorly parallel to each other (the anterior belly was found to be the inferior belly that had developed and reached the superior belly area). For the intermediate morphologies of the Om superior belly observed in the present study, although type 4 was due to the development of an inferior belly, the other three types were considered to be caused by the poor development of the myofibers in the formation process and by the division of the superior belly into two muscles, or secondary lamellar division of the belly with growth.

Aged↗
PubMed2006

Farnesol restores wild-type colony morphology to 96% of Candida albicans colony morphology variants recovered following treatment with mutagens.

Candida albicans is a diploid fungus that undergoes a morphological transition between budding yeast, hyphal, and pseudohyphal forms. The morphological transition is strongly correlated with virulence and is regulated in part by quorum sensing. Candida albicans produces and secretes farnesol that regulates the yeast to mycelia morphological transition. Mutants that fail to synthesize or respond to farnesol could be locked in the filamentous mode. To test this hypothesis, a collection of C. albicans mutants were isolated that have altered colony morphologies indicative of the presence of hyphal cells under environmental conditions where C. albicans normally grows only as yeasts. All mutants were characterized for their ability to respond to farnesol. Of these, 95.9% fully or partially reverted to wild-type morphology on yeast malt (YM) agar plates supplemented with farnesol. All mutants that respond to farnesol regained their hyphal morphology when restreaked on YM plates without farnesol. The observation that farnesol remedial mutants are so common (95.9%) relative to mutants that fail to respond to farnesol (4.1%) suggests that farnesol activates and (or) induces a pathway that can override many of the morphogenesis defects in these mutants. Additionally, 9 mutants chosen at random were screened for farnesol production. Two mutants failed to produce detectable levels of farnesol.

Candida albicans↗
PubMed2005

Shear induces a unique series of morphological changes in translocating platelets: effects of morphology on translocation dynamics.

OBJECTIVE: The platelet glycoprotein (GP) Ib/V/IX complex plays an important role in regulating the morphology of resting platelets and can induce shape change during adhesion to immobilized von Willebrand factor (vWf). In this study we have examined the effects of fluid shear stress on GPIb-dependent changes in platelet morphology during translocation on vWf. METHODS AND RESULTS: We demonstrate that translocating platelets undergo a unique series of morphological changes in response to increasing fluid shear stress. Under moderately low shear conditions (600 s(-1)), initial shape change involved extension of membrane tethers and/or filopodia from the platelet surface. With increasing shear rate, platelets adopted a spherical morphology with numerous surface projections (1800 to 5000 s(-1)). At high wall shear rates (10000 to 20,000 s(-1)), translocating platelets retracted filopodia, developing a smooth ball-like appearance. These changes in morphology were dependent on reorganization of the actin and microtubule components of the cytoskeleton and were regulated by intracellular signaling processes linked to Src kinases. Functionally, alterations in platelet shape had a major effect on translocation dynamics in that conversion from discs to spheres resulted in a 3- to 8-fold increase in rolling velocity. CONCLUSIONS: These studies demonstrate that platelets undergo shear-specific morphological changes during surface translocation on vWf that may serve to regulate translocation dynamics under flow.

Actin Cytoskeleton↗
PubMedDate not supplied

[On the methodology of morphology and levels of morphologic analysis].

Unjustified narrowing of the problems of morphology by merging the terms "morphology" and "anatomy" leads to stagnation in morphology. The merging of "classic" and "modern" biology will enrich both morphology and molecular biology and genetics. The latter will be able apply conceptual models of morphology to more primitive structural level of life. The possibility to apply V. A. Dogel' 's ideas on the role of oligomerization and polymerization in science to the analysis of molecular evolution has been demonstrated with the analysis of DNA content in the genomes of Chordata taken as an example. The data on DNA content do not allow both to consider lungfishes as ancestors of all Tetrapoda and develop monophyletic concept of Tetrapoda origin at the same time. The possibility of application of concepts of comparative morphology to analysis of molecular evolution has been considered.

Anatomy↗
PubMed1998

[Internal standardization of sperm morphology evaluated according to strict morphological criteria].

OBJECTIVE: To evaluate sperm morphology and find cut-off values for local andrology lab based on morphological strict criteria. To compare the results to WHO guidelines. MATERIAL AND METHODS: Strict morphological criteria were applied to 300 sperm smears stained according to the Papanicolaou method. Specific sperm defects were described in details. The results were analyzed statistically. RESULTS: The normal sperm morphology was found in 18.54% of cases, which is less than the cut-off value suggested in the WHO guidelines. The lab cut-off value aimed by the 25th percentile was 8%. CONCLUSION: Sperm morphology requires broader multi-center standardization to enable compatible exchange of morphological data and find predictive factors of sperm fertilizing potential.

Adult↗
PubMed1986

Limb morphology of domestic and wild canids: the influence of development on morphologic change.

Biomechanical hypotheses are often invoked to explain the characteristic scaling of limb proportions. Patterns of static allometry and morphologic diversity, however, may also reflect the developmental mechanisms underlying morphologic change. In this study I document the importance of such developmental influences on the evolution of limb morphology in the extremely polymorphic domestic dog and in wild canid species. I use bivariate and discriminant function analyses to compare the limb morphology of adult dogs and wild canid species. I then compare ontogenetic allometry of four dog breeds with static allometry of domestic and wild canids. Results reveal, first, that there is considerable similarity between dogs and wild canid species; many wolf-like canids cannot be distinguished from domestic dogs of equivalent size. However, all dogs are consistently separated from fox-sized, wild canids by subtle but evolutionarily significant differences in olecranon, metapodial, and scapula morphology. Second, in domestic dogs the pattern of static allometry is nearly identical to that of ontogenetic allometry. This finding can be attributed to simple heterochronic alterations of postnatal growth rates. Apparently the diversity of limb proportions among adult domestic dogs and the observed difference between dogs and wild canids are somewhat predetermined, as they directly reflect the diversity of limb proportions evident during development of the domestic dog.

Animals↗
PubMed1994

Outgrowth morphology and intracellular calcium of crustacean neurons displaying distinct morphologies in primary culture.

Peptide-secreting neurons from crustacean X-organ regenerating in defined culture possess different ionic current profiles correlated with two distinct morphological types, veiling and branching; voltage-dependent Ca2+ current is prominent in neurons consistently extending large veils, but is small in neurons that repetitively branch. Intracellular free calcium levels ([Ca2+]i) have been implicated in the regulation of neurite outgrowth underlying the establishment of distinct morphologies. Here, basal [Ca2+]i was measured by fura-2 fluorescence ratio imaging from these morphologically distinct neurons and compared. Both morphological types can extend out processes over a [Ca2+]i range (approximately 50 to 300 nM) that is much greater than that reported for neurons of other phyla. Application of high K+ saline led to increases in [Ca2+]i in soma, neurite, and lamellipodium of veiling neurons. Increases were greater for veiling than branching neurons. These observations were consistent with the previous voltage clamp data for calcium currents. Media altered to perturb [Ca2+]i were used to assess the role of [Ca2+]i in veiling or branching outgrowth programs. Outgrowth of veiling cells was arrested by addition of 100 microM Cd2+, a calcium channel blocker. Outgrowth resumed following brief exposures to Cd2+. Branching neurons were unaffected by Cd2+. Cd2+ at lower levels (10 microM) had no effect on outgrowth of either neuronal type, whereas at higher levels (1 mM), outgrowth of both types was arrested. Reduction of extracellular sodium to 0.001 of normal concentration stopped veiling outgrowth, but branching outgrowth continued, although it was less robust. Addition of tetrodotoxin (1 microM) did not alter outgrowth of either neuronal type relative to controls. Thus, peptidergic neurons of differing intrinsic morphologies maintain similar basal [Ca2+]i levels under identical culture conditions, yet show differing sensitivities to manipulations influencing [Ca2+]i with respect to regenerative outgrowth, but not its form.

Animals↗
PubMed2005

Multi-gene phylogenies indicate ascomal wall morphology is a better predictor of phylogenetic relationships than ascospore morphology in the Sordariales (Ascomycota, Fungi).

Ascospore characters have commonly been used for distinguishing ascomycete taxa, while ascomal wall characters have received little attention. Although taxa in the Sordariales possess a wide range of variation in their ascomal walls and ascospores, genera have traditionally been delimited based on differences in their ascospore morphology. Phylogenetic relationships of multiple representatives from each of several genera representing the range in ascomal wall and ascospore morphologies in the Sordariales were estimated using partial nuclear DNA sequences from the 28S ribosomal large subunit (LSU), beta-tubulin, and ribosomal polymerase II subunit 2 (RPB2) genes. These genes also were compared for their utility in predicting phylogenetic relationships in this group of fungi. Maximum parsimony and Bayesian analyses conducted on separate and combined data sets indicate that ascospore morphology is extremely homoplastic and not useful for delimiting genera. Genera represented by more than one species were paraphyletic or polyphyletic in nearly all analyses; 17 species of Cercophora segregated into at least nine different clades, while six species of Podospora occurred in five clades in the LSU tree. However, taxa with similar ascomal wall morphologies clustered in five well-supported clades suggesting that ascomal wall morphology is a better indicator of generic relationships in certain clades in the Sordariales. The RPB2 gene possessed over twice the number of parsimony-informative characters than either the LSU or beta-tubulin gene and consequently, provided the most support for the greatest number of clades.

Ascomycota↗
PubMed2005

Confrontation of morphological and molecular data: the Praomys group (Rodentia, Murinae) as a case of adaptive convergences and morphological stasis.

Phylogenetic relationships in a group of 21 African rodent species designated as the Praomys group (Murinae) were investigated using morphological characters and sequence data from the complete mitochondrial cytochrome b gene and nuclear IRBP gene fragment (840bp). The molecular results confirm the monophyly of the Praomys group, including the species Malacomys verschureni, while the other Malacomys species appear very divergent. The basal relationships within the Praomys group are poorly resolved, suggesting a rapid radiation at about 7-9 million years ago based on genetic divergence rates calibrated from the fossil record. Discrepancies between molecular and morphological results probably reflect of numerous convergences as well as variations in the rates of morphological evolution among lineages. Reconstructions of the ancestral character states suggest a savannah origin for the Praomys group, along with some morphological traits conserved by stasis in savannah taxa. At the same time, forest taxa seem to be characterized by an accelerated morphological evolution, with acquisition of convergent adaptive characters.

Adaptation, Biological↗
PubMed1995

Symptoms, stenosis and carotid plaque morphology. Is plaque morphology relevant?

OBJECTIVES: To study the relationship between carotid plaque morphology and the degree of stenosis on Duplex ultrasonography and symptoms. DESIGN: Prospective open clinical study. METHODS: 2,590 patients with 5,180 carotid arteries were scanned, 4,560 were initially analysed in terms of symptoms but 54 were excluded, leaving a total of 4,258. RESULTS: Localising symptoms were present with respect to 1,342 vessels (29.4%). Two-thirds of symptomatic patients had normal carotid arteries. Tight stenosis (80-99%) was more likely to be associated with symptoms than low-grade (20-79%) stenosis (chi 2 = 28.0, p < 0.0001). Plaque type was identified in 1,558 bifurcations (36.6%). Heterogeneous type I & II plaques accounted for one third of plaques. There was a relationship between plaque morphology and degree of stenosis. At < 20% stenosis only 4.4% of plaques were heterogeneous whereas at 80-99% stenosis 84.5% of plaques were heterogeneous. Amaurosis fugax was the only symptom that had any association with a particular plaque morphology. Seventy-two percent of plaques associated with this symptom were heterogeneous in nature. CONCLUSIONS: Carotid plaque morphology and degree of internal carotid stenosis are mutually dependent factors and both reflect the severity of atherosclerotic disease. Plaque morphology does not add to the sensitivity of stenosis in predicting the presence of symptoms.

Blindness↗
PubMed2004

Morphological family size in a morphologically rich language: the case of Finnish compared with Dutch and Hebrew.

Finnish has a very productive morphology in which a stem can give rise to several thousand words. This study presents a visual lexical decision experiment addressing the processing consequences of the huge productivity of Finnish morphology. The authors observed that in Finnish words with larger morphological families elicited shorter response latencies. However, in contrast to Dutch and Hebrew, it is not the complete morphological family of a complex Finnish word that codetermines response latencies but only the subset of words directly derived from the complex word itself. Comparisons with parallel experiments using translation equivalents in Dutch and Hebrew showed substantial cross-language predictivity of family size between Finnish and Dutch but not between Finnish and Hebrew, reflecting the different ways in which the Hebrew and Finnish morphological systems contribute to the semantic organization of concepts in the mental lexicon.

Cross-Cultural Comparison↗
PubMed1995

Molecules versus morphology: the detection of selection acting on morphological characters along a cline in Drosophila melanogaster.

This work examines the nature of north-south clinal variation in morphological characters in Drosophila melanogaster. Isofemale lines were established from flies collected along a transect extending from Winnipeg, Manitoba (Canada) to Tampa Bay, Florida (U.S.A.). Offspring from different lines within each location were then cultured under standardized conditions and used to examine phenotypic variation in seven morphological characters along the cline. In addition, allozyme variation at seven polymorphic loci was examined for the same set of clinal populations. Scutellum length and wing length show the strongest clinal trends. Clinal variation is nonmonotonic, with larger flies in the middle latitudes and smaller flies in the north and south. This result contrasts with other studies which have shown monotonic clines. Patterns of population subdivision were different for the different characters. This implies that there are different selective forces acting on the different morphological characters. Based on a comparison of morphological and molecular population subdivision for adjacent populations it is inferred that natural selection is operating to maintain a high level of population subdivision for wing width and the first principal component between one of the sets of populations. A combined approach using molecules and morphology may provide an alternative to retrospective selection analysis for detecting selection in nature.

Animals↗
PubMed2003

Association between condylar position, joint morphology and craniofacial morphology in orthodontic patients without temporomandibular joint disorders.

The present study investigated condylar position and joint morphology in adolescent patients and elucidated the possible association between the joint structure and condylar position, and craniofacial morphology. Sixty-five adolescent patients were selected as subjects and their tomograms and lateral cephalograms were analysed. No significant differences in joint spaces were found between the right and left temporomandibular joints. Both the condyles in this population were located slight anteriorly in the glenoid fossa. With respect to the association between condylar position, joint morphology and craniofacial morphology, the ramus plane angle also exhibited significant negative correlations with posterior, lateral and medial joint spaces. Furthermore, there was a significant negative correlation between the gonial angle and the anterior joint space. These findings imply that the condyle was likely to show more posterior position in the glenoid fossa when the mandible exhibited clockwise rotation. In conclusion, the condyle in the adolescent subjects showed a symmetrical anterior position relative to the glenoid fossa. In addition, the joint spaces and it ratios were significantly related to the craniofacial morphology associated with vertical dimension. It is suggested that the condylar position may be affected by craniofacial growth pattern.

Adolescent↗
PubMed1995

Population structure of morphological traits in Clarkia dudleyana. I. Comparison of FST between allozymes and morphological traits.

Studies of genetic variation at allozyme loci, assumed to be selectively neutral, have provided valuable insights into the genetic structure of numerous populations. The degree to which population structure of allozyme variation reflects that of quantitative traits, however, is not well resolved. Here, we compare estimates of population differentiation (FST) of 11 populations for allozymes with those for nine discrete and nine continuous morphological traits. Overall, the allozymes have the lowest FST estimates, indicating relatively little population differentiation. Excepting two traits, petal width and long internode length, the continuous morphological traits have estimates similar to those from allozymes. The discrete morphological traits tend to have the highest estimates. On a single trait basis, estimates of FST for four discrete and two continuous traits are higher than those for allozymes. A more detailed (narrow-sense quantitative) genetic study of two populations suggests that these estimates of FST may underestimate the true value because of dominance. Clustering analyses show that the pattern of differentiation for the discrete morphological traits strongly reflects the geographical distribution of the populations, whereas the patterns for the continuous traits and allozymes do not. These results suggest that selection has been occurring on the discrete morphological traits, selecting toward a common optimum within each geographic group, and optima differing among geographic groups.

Cluster Analysis↗
PubMed2003

A morphological and chromosomal study of blastocysts developing from morphologically suboptimal human pre-embryos compared with control blastocysts.

BACKGROUND: IVF laboratories performing embryo transfer at day 2 or 3 after fertilization are currently discarding pre-embryos considered suboptimal using morphological criteria. The objective of this study was to investigate whether blastocysts, cultured from such pre-embryos (surplus), were chromosomally and morphologically normal. As a control group we used morphologically good quality embryos (GQE), cultured to the blastocyst stage. METHODS: Human pre-embryos considered suboptimal were cultured to the blastocyst stage. As a control group, frozen-thawed pre-embryos of good quality were cultured under identical conditions. The chromosomal status of the blastocysts obtained was studied by multi-colour fluorescence in-situ hybridization for chromosomes 13, 16, 18, 21, 22, X and Y. RESULTS: There is, on average, a significantly higher degree of chromosomal aberrations in blastocysts derived from surplus pre-embryos compared to blastocysts derived from GQE, and the chromosomal aberrations are generally found in a higher number of blastomeres per blastocyst. In addition, blastocysts from surplus pre-embryos had significantly poorer morphology compared to GQE. Improvement in morphology and/or developmental rate in surplus pre-embryos between day 2 and day 3 did not predict a morphologically/chromosomally normal blastocyst. However, this study shows that close to half of the surplus pre-embryos that reach the blastocyst stage can be considered chromosomally normal when assessed for these seven chromosomes. Furthermore, we found that chromosomal aberrations were more concentrated in a particular cell population within blastocysts derived from GQE, compared with surplus blastocysts. CONCLUSIONS: The study suggests that even if the IVF laboratory is on average making the correct decision about the potential of a pre-embryo, surplus pre-embryos that might become chromosomally normal blastocysts are still being discarded.

Adult↗
PubMed2004

The morphological normalcy of the sperm nucleus and pregnancy rate of intracytoplasmic injection with morphologically selected sperm.

BACKGROUND: Our preceding studies have already demonstrated the advantage of intracytoplasmic morphologically selected sperm injection (IMSI) over the conventional IVF-ICSI procedure in terms of pregnancy rate. This study was undertaken to determine whether the increased pregnancy outcome was attributable to the preferred nuclear morphology of the selected spermatozoa, and not to the special sperm preparation technique modified by IMSI. METHODS: Comparison between two matched IMSI groups, i.e. negative comprising 38 cycles, where no spermatozoa with intact nuclei were available for microinjection; and positive, involving ovum microinjection by spermatozoa with strictly defined morphologically normal nuclei. RESULTS: Implantation and pregnancy rates were significantly higher, and abortion rates significantly lower, in the positive group compared with the negative group (25.0+/-25.9 versus 5.9+/-12.9%, F=15.8, P< or =0.01; 52.6 versus 18.4%, chi2=9.7, P< or =0.01; and 10.0 versus 57.1%, chi2=7.1, P< or =0.02, respectively). CONCLUSIONS: Implantation and pregnancy by ICSI is associated with morphological nuclear normalcy of sperm. Sperm with a morphologically abnormal nucleus usually have low fertility potential, but some with certain nuclear abnormalities may still be able to produce pregnancy following ICSI.

Adult↗
PubMed1989

[Morphological study of periodontal tissues in the initial stage of periodontal disease. Part 1. Application of a morphological measurement and a system for evaluating the periodontal status].

The functional aberration of occlusion, based on the morphology of the alveolar process, causes chronic irritation of the periodontium in addition to the concomitant effect of other local environment factors. This investigation was designed to study the role of morphological characteristics in the periodontal disease process. The periodontal health of 22 subjects was recorded by clinical and roentgenological measurements of the loss of periodontal tissue. The criteria for this selection were no loss of or a crowding of adjoining teeth and no disharmony in occlusal contact. Morphological data were measured around the premolars and molars of lower jaws on the study models individuals, in bucco-lingual width of the alveolar bone in relationship to the width of the crown and the sagittal figure of the Spee curve etc. by using a three-dimensional analyzer. The subjects were categorized as Type II when the records indicated a ratio of the crown width/bone width of 1/1.2. Types I and III, depended on a greater and smaller ratio, respectively. Type W symbolized the alveolar process, of which the interproximal bone showed a considerable curvature mediodistally. Type F showed a flat pattern. The sagittal figure of the Spee curve was divided into four patterns: Pattern A or B, when the cusp of the canine and first premolar leveled over or on the occlusal plane; Pattern C, when the cusp of the canine leveled over and the first premolar under the occlusal plane, and Pattern D, when all cusps, canine, premolar and molar, were under the occlusal plane. The distance from the occlusal plane to the deepest point of the Spee curve was divided into four groups: Pattern a, when the distance was 0-1.0 mm, Pattern b, 1.1-2.0 mm, Pattern c, 2.1-3.0 mm and Pattern d, 3.1-4.0 mm. These results suggest that the morphological evaluation is a useful diagnostic indicators on a rational basis. The morphological characteristics might be related to the presence of periodontal disease and allowed to speculate the pathological changes in established stage, and also to the response to periodontal treatment in the initial stage of periodontal disease.

Alveolar Process↗
PubMed1996

Functional morphology of the lemuriform wrist joints and the relationship between wrist morphology and positional behavior in arboreal primates.

A comparative study of carpal joint structure and function in six Malagasy lemuriforms was undertaken to test predicted morphoclines in carpal joint morphology between pronograde and orthograde arboreal primates. Patterns of movement at the wrist during locomotion were observed and described for the lemuriform species Lemur fulvus and Propithecus verreauxi. Lemur fulvus, which assumes a pronograde posture during locomotion, extends and pronates the wrist during the support phase of quadrupedal walking and running stride cycles. Furthermore, the forearm of this species exhibits some transverse movement across the proximal wrist joint during the support phase. In contrast, the indriid Propithecus maintains the hand and wrist in a flexed and partially supinated position during vertical clinging and suspensory postures. Habitual quadrupedal and vertical postures in Malagasy primates are in turn related to very different patterns of carpal joint morphology and articular mechanics. Those lemurs which are predominantly pronograde share a series of structural features related to stabilizing the antebrachiocarpal joint during extension and mediolateral deviation and the midcarpal joint during pronation: an intraarticular labrum is present on the inner portion of the radiocarpal ligament, the radiocarpal articular surface is quite flat dorsoventrally, the capitate-trapezoid embrasure is expanded dorsally, and development of the radial and ulnar styloids is more pronounced. The wrists of Propithecus, Avahi, and Lepi-lemur (vertical clingers) differ from those of quadrupedal lemuriforms in possessing a suite of morphological features related to stabilizing the wrist during antebrachiocarpal flexion and midcarpal supination: the radiocarpal articular surface is deeply curved and tilted anteriorly, the dorsal radiocarpal ligament is very broad, thick, and fibrous, the hamate's triquetral facet is directed proximodistally, and the capitate-trapezoid embrasure is dorsally constricted and expanded palmarly. These observed contrasts in carpal form and function are used to define further the morphological features related to orthograde posture in several lineages of arboreal primates.

Animals↗