A twin study of dental dimension. II. Independent genetic determinants

To demonstrate the presence of independent genetic determinants of multiple correlated tooth dimensions from twin data, a multivariate analysis was performed on the covariance matrices of monozygotic and dizygotic within-pair differences for mesiodistal and buccolingual dimensions of 28 teeth of the secondary dentition. The results provided strong evidences that the correlation among tooth dimensions is primarily genetic in origin, probably attributable to the pleiotropic action of either independent genes or groups of genes. Among the genetic factors that were identified, one appeared to affect the maxillary teeth in general while a second influenced primarily the anterior mandibular teeth. There was a striking tendency for homologous measurements on the right and left sides to be associated with the same genetic factor. In contrast, genetic determination of the maxillary and mandibular dentition seemed to be independent of each other, and a wider range of genetic factors were found to influence the mandibular than the maxillary teeth, suggesting that a differential degree of evolutionary stability may have been achieved in the teeth of the two jaws.     

Genetic and environmental influences on bilateral dental asymmetry in Northwest Indian twins

The role of genetic and environmental factors on dental asymmetry (in maximum crown dimensions) was examined using 58 pairs of twins (23 MZ and 35 DZ) from Chandigarh, India. The t'-test for equality of means by zygosity showed only one variable significantly different among 56: this is ascribable to Type 1 error. Heterogeneity of MZ-DZ total variance was observed in 42.9% of traits of the two types (fluctuating and directional) of bilateral asymmetry. In general, MZ twins showed higher total variance than DZ pairs. MZ twins also showed stronger environmental covariance for a majority of the traits. Dental asymmetry measures thus yielded consistently low genetic variance ratios and indicated predominantly complex environmental determinism. Since fluctuating asymmetry is widely believed to be an environmental stress indicator, this data set allows confirmation of methods for detecting unequal environmental influences on the zygosities which bias estimates of genetic variance and heritability.     

On the meaning of increased fluctuating dental asymmetry: a cross populational study.

Suarez reports a greater magnitude of fluctuating dental asymmetry for Neandertal sample when compared with a sample of modern Ohio whites. He postulates that this greater antimeric variance could be due to a greater degree of inbreeding in the Neandertal populations. In the present investigation, the magnitude of fluctuating dental asymmetry is evaluated for Eskimo and Pueblo populations. These populations were found to exhibit dental variance of equal magnitude to that of the Neandertal population. As these populations are not highly inbred, a stress related mechanism is suggested to explain these observations and the inbreeding hypothesis is rejected. The implications of this mechanism to Brace's Probable Mutation Effect are discussed.     

Efficacy of imagery rehearsal treatment related to specialized populations: A case study and brief report.

This brief report examines the impact of imagery rehearsal treatment (IRT) on a 10-year-old boy with mild mental retardation and psychiatric illness. There is relatively little published information on the use of IRT to treat nightmares in children. The results in this case are consistent with reports of positive results from IRT in other studies with different populations. The findings in this study suggest that the limitations of IRT may not yet be known, and controlled studies with various populations are needed. This article also examines other factors present in this particular case that did not seem to impact the outcome, hence providing IRT with a robust appearance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A study of the taxonomic significance of the dental arch.

Sixteen dimensions were measured from the maxillary and mandibular dental arches of different ethnic groups of man, apes and monkeys. Multivariate analysis showed that discrimination was possible among the ethnic groups of man on the one hand and between the ape and monkey samples on the other. Nevertheless, the actual degree of discrimination between the primate samples depended upon whether the maxillary or mandibular arch dimensions were analysed. Furthermore, subsequent inclusion of the dental arch dimensions of fossil hominoid samples into the analysis confirmed the taxonomic significance of the dental arch, although its importance must await the acquisition of the more non-human primate data.     

Polymerization of pNcollagen I and copolymerization of pNcollagen I with collagen I. A kinetic, thermodynamic, and morphologic study.

Previous observations established that pNcollagen III copolymerized with collagen I and decreased the diameter of the fibrils formed (Romanic, A.M., Adachi, E., Kadler, K.E., Hojima, Y., and Prockop, D.J. (1991) J. Biol. Chem. 266, 12703-12709). Here, procollagen I alone or mixtures of procollagen I and pCcollagen I were incubated with procollagen C-proteinase to generate pNcollagen I or mixtures of pNcollagen I and collagen I. The results confirmed previous reports that pNcollagen I assembles into sheet-like structures. They also demonstrated that polymerization of pNcollagen I exhibits a lag period and propagation phase similar to those seen with other protein self-assembly systems. In addition, the results demonstrated that pNcollagen I formed true copolymers with collagen I in that the presence of pNcollagen I increased the lag time, decreased the propagation rate, and increased the concentration of collagen I in solution at equilibrium. Copolymerization of pNcollagen I with collagen I, however, differed in two features from copolymerization of pNcollagen III with collagen I. One was that, in confirmation of previous work, copolymerization of pNcollagen I with collagen I markedly altered the circularity of the fibrils formed. The second difference was that the copolymerization increased the concentration in solution at equilibrium of pNcollagen I whereas copolymerization with collagen I was previously shown to decrease the concentration in solution of pNcollagen III. The increase in concentration in solution of pNcollagen I was explicable either by the assembly of soluble oligomers of pNcollagen I and collagen I, or by subtle changes in the activities of pNcollagen I and collagen I in the solid-phase. Comparison with previous data with pNcollagen III indicated that although pNcollagen I and pNcollagen III copolymerize with collagen I, there are marked differences in the two kinds of copolymers.     

Comparative study of observed actions,motor imagery and control therapeutic exercise on the conditioned pain modulation in the cervical spine: a randomized controlled trial

Abstract

Aim: The aim of this study was to compare the effects of cervical exercise, motor imagery (MI) and action observation (AO) of cervical exercise actions on conditioned pain modulation and pressure pain thresholds. The second objective was to assess the effects of these interventions on cervical motor activity (ranges of motion and muscle endurance), attention, and the ability to generate motor images.

Study design: Single-blinded randomized controlled trial.

Materials and methods: Fifty-four healthy subjects were randomly assigned to each group. Response conditioned pain modulation, pressure pain threshold, were the main variables. The secondary outcome measures included, cervical range of motion, Neck flexor endurance test, mental movement representation associated and psychosocial variables.

Results: All groups showed significant differences in time factor for all evaluated variables (p?<?.01) except pressure pain threshold over the tibial region. The post hoc analysis revealed significant within-group differences in the AE and AO groups in conditioned pain modulation (p?<?.05), with medium effect size in time [AE (d –0.61); AO (d –0.74)].

Conclusion: The results showed that within-group changes in conditioned pain modulation, cervical muscle endurance, and attention where founded only in the AE and AO groups. Variations in pain thresholds at pressure in the trapezium area were also obtained in the three groups. Changes in the ranges of flexion-extension and rotation movement were presented exclusively in the exercise group, and in the capacity to generate motor images only in the AO group. However, there was no difference in the pressure pain threshold over the tibial region.     

A comparative study of tooth and dental arch dimensions in Jewish children of different ethnic descent. I. Kurds and Yemenites

Dental casts of 99 Kurdish and 98 Yemenite Jewish children evenly distributed between the sexes, aged 12 years, were measured for mesio-distal and buccolingual tooth dimensions, and arch depth and width. Dental dimensions showed significant differences between the two groups in certain permanent teeth in mesiodistal length, while in the buccolingual diameter the differences did not reach statistical significance. Dental arch form in Kurdish children was more rounded due to significantly bigger arch width, while arch depth was not significantly different from Yemenites. Intragroup sex differences were found in both groups with reference to arch dimensions, while in the dental parameters they were more strongly expressed in Kurdish children.     

A multivariate twin study of hippocampal volume, self-esteem and well-being in middle-aged men

Self-esteem and well-being are important for successful aging, and some evidence suggests that self-esteem and well-being are associated with hippocampal volume, cognition and stress responsivity. Whereas most of this evidence is based on studies on older adults, we investigated self-esteem, well-being and hippocampal volume in 474 male middle-aged twins. Self-esteem was significantly positively correlated with hippocampal volume (0.09, P = 0.03 for left hippocampus, 0.10, P = 0.04 for right). Correlations for well-being were not significant (Ps > 0.05). There were strong phenotypic correlations between self-esteem and well-being (0.72, P < 0.001) and between left and right hippocampal volume (0.72, P < 0.001). In multivariate genetic analyses, a two-factor additive genetic and unique environmental (AE) model with well-being and self-esteem on one factor and left and right hippocampal volumes on the other factor fits the data better than Cholesky, independent pathway or common pathway models. The correlation between the two genetic factors was 0.12 (P = 0.03); the correlation between the environmental factors was 0.09 (P > 0.05). Our results indicate that largely different genetic and environmental factors underlie self-esteem and well-being on one hand and hippocampal volume on the other.     

A phylogenetic study of titi monkeys,genusCallicebus, based on cranial measurements: I. Phyletic groups ofCallicebus

Examinations of 23 forms ofCallicebus were made to elucidate their phylogenetic relationships based on cranial measurements. Multivariate statistical methods of distance analysis utilizing Q-mode correlation coefficients and principal component analysis were employed. As a result, the following five distinct groups were recognized morphometrically among the 23 species and subspecies: theDonacophilus, Cupreus, Moloch, Personatus, andTorquatus groups. Moreover, the phenetic characters of cranial size, karyotype, pelage coloration, and geographic range were consistent with the results of this group classification. It could be safely concluded therefore that these groups represented phylogenetically independent groups, in view of the fact that the rate of character differentiation was not appreciably different among closely related groups. Of the five groups, thePersonatus andTorquatus groups were respectively considered to maintain a higher peculiarity of character differentiation within theCallicebus phylogeny, since these two groups individually displayed the higher magnitudes of differentiation in both their craniometric shape and some phenetic features. Conversely, the other three groups were considered to be closer to each other in theCallicebus phylogeny.     

A controlled study of Tourette syndrome. I. Attention-deficit disorder, learning disorders, and school problems

Tourette syndrome (TS) is a common, hereditary, neurobehavioral disorder of childhood. To determine the frequency of various behavioral manifestations, we have compared 47 random normal controls to 246 patients with TS, 17 with attention-deficit disorder (ADD), and 15 with ADD secondary to a TS gene (ADD 2(0) TS). All subjects were examined prospectively with a 425-item questionnaire based on the Diagnostic Interview Schedule and the Diagnostic and Statistical Manual of Mental Disorders (DSM III). The TS patients were divided into grade 1 (too mild to treat [17.5%]), grade 2 (requiring treatment [58.9%]), and grade 3 (severe [23.6%]). Patients in all three grades of TS were significantly different from controls for DSM III symptoms of inattention, impulsivity, and hyperactivity. Sixty-two percent of TS patients had ADD, compared with 6.3% of controls; and 48.8% had ADD with hyperactivity (ADDH), compared with 4.2% of controls. In the majority of TS patients, the natural history of the disease was to start with ADDH and 2.4 years later develop motor and vocal tics. Among TS patients, 39% had previously received medication for ADDH or behavior problems, compared with 2% of the controls. Although stimulants can occasionally exacerbate tics, there was no evidence that stimulants cause TS and they are often a valuable adjunct to the treatment of TS. It is estimated that 10%-30% of ADDH is due to or associated with the presence of a TS gene. TS patients had a significantly increased frequency of (1) attending classes for the educationally handicapped, (2) placement in classes for the severely emotionally disturbed, (3) attending any special classes, (4) severe test anxiety, (5) stuttering, (6) letter, number, or word reversal, (7) reading very slowly, and (8) poor retention of material read. A reading-problem score (dyslexia) greater than or equal to 3 was present in 26.8% of TS patients, compared with 4.2% of controls. Number reversal, word reversal, and poor retention were significant even for the TS patients with tics too mild to treat. The multiple ways in which TS impacts school performance, as well as potential remedies, are discussed.     

A study of phosphoglycerate kinase in human erythrocytes. I. Enzyme isolation, purification and assay.

The enzyme ATP-3-phospho-D-glycerate-1-phosphotransferase (EC 2.7.2.3) (phosphoglycerate kinase) has been isolated from human red cells in crystalline form by a modification of the method of Yoshida and Watanabe (1972) J. Biol. Chem. 247, 440-445). The crystalline enzyme was further purified by electrofocusing using carrier ampholytes (pH 7-9). The isoelectric point of phosphoglycerate kinase was estimated to be 8.75. The specific activity of purified phosphoglycerate kinase from electrofocusing was 2200 units per mg of protein at pH 8.3 (37 degrees C). Enzyme activity was assayed in the forward direction leading from 1,3-diphosphoglycerate to a 3-phosphoglycerate using a fluorimetric procedure for NAD-coupled enzymes for the measurement of the reaction rate at very low substrate concentrations. The auxiliary indicator enzymes were added in excess to yield true initial velocity kinetics, i.e. with no time lag upon addition of substrate (1,3-diphosphoglycerate). This was established theoretically using a mathematical model and confirmed experimentally. Further phosphoglycerate kinase was shown to be the rate-limiting step when the assay conditions were varied.     

Alkali burns of the rabbit cornea. I. A histochemical study of beta-glucuronidase, beta-galactosidase and N-acetyl-beta-D-glucosaminidase.

In alkali burned rabbit corneas activities of beta-glucuronidase, N-acetyl-beta-D-glucosaminidase and acid beta-galactosidase were studied histochemically in various time intervals after the traumatization. The technic with semipermeable membranes was employed. Within four days after the injury enzyme activities in the traumatized area were almost lacking. The corresponding activities in the unaffected part of the cornea were within the norm. On the 7th day enzyme activities were on an increase (but still subnormal) in the traumatized area. This area was surrounded by a zone of keratocytes with high levels of enzyme activities. This was particularly remarkable in keratocytes subjacent to the epithelium. The activation of all enzymes studied was present in the basal layer of the epithelium and in the endothelium as well. On the 14th day enzyme activities in the traumatized area were nearly restored and on the 32nd day they could not be distinguished from the normal cornea. Beta-galactosidase displayed a relatively maximal increase in the activity of all enzymes investigated.     

A study of wing morphology and fluctuating asymmetry in interspecific hybrids between Drosophila buzzatii and D. koepferae

In this work we investigate the effect of interspecific hybridization on wing morphology using geometric morphometrics in the cactophilic sibling species D. buzzatii and D. koepferae. Wing morphology in F₁ hybrids exhibited an important degree of phenotypic plasticity and differs significantly from both parental species. However, the pattern of morphological variation between hybrids and the parental strains varied between wing size and wing shape, across rearing media, sexes, and crosses, suggesting a complex genetic architecture underlying divergence in wing morphology. Even though there was significant fluctuating asymmetry for both, wing size and shape in F₁ hybrids and both parental species, there was no evidence of an increased degree of fluctuating asymmetry in hybrids as compared to parental species. These results are interpreted in terms of developmental stability as a function of a balance between levels of heterozygosity and the disruption of coadaptation as an indirect consequence of genomic divergence.     

Macaca thibetana at Mt. Emei,China: I. A cross-sectional study of growth and development

Six free-ranging groups of Macaca thibetana were studied at Mt. Emei, in southwest China. Patterns of growth and development observed during the study are described for this species for the first time. Data were collected mainly during the birth season of 1986. Food handouts made possible the measurement of body weight and sitting height. Changes in fur color and growth of forehead hair were noted. Dark hair appeared on the broad white forehead of infants at the end of the third month. A triangular patch formed about 30 days later, and full cover developed within 4.5 to 5 months. For the first 1 or 2 weeks, the fur was blackish; it then became yellow, and by the age of 3.5–4.5 months, it was brown or blackish, i.e., adult color. Growth data on body weight and sitting height for different age-sex classes were collected. For adult males, body weight was 18 kg, sitting height (SH) 55 cm, and ponderal index 33. For adult female, body weight was 13 kg, sitting height 47 cm, and ponderal index 27. Females were considered to be adult at age 5 years.     

Regeneration of plants from Ipomoea cairica L. protoplasts and production of somatic hybrids between I. cairica L. and sweetpotato, I. batatas (L.) Lam.

Plants were regenerated from mesophyll protoplasts of Ipomoea cairica L., a wild relative of sweetpotato (Ipomoea batatas (L.) Lam.), and somatic hybrids between I. cairica L. and sweetpotato cv. Xushu 18 were obtained by PEG-mediated method. I. cairica L. protoplasts were isolated from the leaves of in vitro grown plants and cultured in a modified MS medium containing 0.05 mg l⁻¹ 2,4-D and 0.5 mg l⁻¹ kinetin. Nine weeks after plating, the obtained small calluses up to about 2 mm in diameter were transferred to solid MS medium supplemented with 0.05 mg l⁻¹ 2,4-D and 0.5 mg l⁻¹ kinetin for callus proliferation. Three weeks after transfer, the calluses were transferred to MS medium supplemented with 0–1.0 mg l⁻¹ IAA and 1.0–3.0 mg l⁻¹ BAP and further to hormone-free MS medium for plant regeneration. The frequencies of calluses forming plants ranged from 6.0% to 41.3% based on the different concentrations of IAA and BAP, and 2.0 mg l⁻¹ BAP gave the highest regeneration frequency of protoplast-derived calluses in I. cairica L.. The regenerated plants, when transferred to soil, showed 100% survival. No morphological variations were observed. Mesophyll protoplasts of I. cairica L. were fused with protoplasts isolated from embryogenic suspension cultures of Xushu 18 by PEG-mediated method. The fused products were cultured with the best protoplast culture system of I. cairica L.. Finally, 114 plants were produced from 63 of the 182 calluses derived from the fused protoplasts, and 46 plants of them were confirmed to be somatic hybrids through peroxidase isozyme, RAPD, morphological and cytological analyses.     

Nonspecific binding of lac repressor to DNA. I. An absorption and circular dichroism study

Nonspecific binding of lac repressor on DNA has been studied by absorption and circular dichroism (CD) spectroscopies. In a first step, the complex formation is accompanied by an absorption difference spectrum and a change of the CD signal of the DNA. The absorption difference spectrum is mainly due to a spectral change of the DNA. The variation of the CD signal has been analyzed according to a model calculation, which takes into account the fact that the excluded site is shorter than the perturbed site. We found that in this first step one repressor can bind every 14 +/- 2 base-pairs, whereas one repressor perturbs 22 +/- 2 base-pairs. In a second step, more repressor can bind on DNA, but without further change in the absorption and CD spectrum, indicating that another binding process occurs. The model calculation developed here is general for all binding processes inducing a perturbation over a length of DNA longer than that of the excluded site.     

Dermatoglyphic variation in the human populations of the North Pennine Dales,North England. I. Sex differences,bilateral asymmetry,digital diversity and regional variation

The North Pennine Dales are sparsely populated and deeply indented valleys in the central uplands of northern England. Travel to service centres on the surrounding low lying terrain, especially to the industrial conurbations, is channelled by way of the dale mouths. Communication over the dale heads is difficult and is thus much dictated by topography and by the orientation of each dale. This paper represents the first of two reports on the finger and palmar dermatoglyphics of the populations. Basic data are presented on sex differences, bilateral asymmetry and digital diversity. Univariate statistical tests have been carried out between the dales' populations for several stages based on the selection of individuals by ancestry. Several significant differences occur but no more than would be expected by chance. Distinct spatial patterning does recur for several variables, but on the available data a univariate approach has been unsuccessful in determining the nature and causes of overall population interrelationships.