Manual asymmetry in children is related to parameters of early development and familial sinistrality

The possible relationships of the manual preference (handedness) of primary school children with the parameters of their development (prenatal and during the first two years of life) and the existence of left-handed close relatives were analyzed. The percentage of left-handers was higher among children born after some complications during pregnancy or delivery and among children having left-handed relatives. The effects of the two factors were not correlated. It has also been found that the infants having left-handed first-degree relatives were, on average, larger than other ones.     

Energetics of left and right handed models of DNA

It has been shown by model building studies that various right handed and left handed models are compatible with X-ray data of B-DNA and C-DNA. These models are also found to be in good agreement with infrared dichroism data. Detailed potential energy calculations have now been carried out for these models, viz., right and left handed B-DNA and right and left handed C-DNA. It is found that base sugar stacking and interactions involving the phosphate groups are the dominant forces for stabilizing a particular structure. For some sequences, viz., A-A, T-A and C-A, left handed stacking is quite favourable in both B and C structures. But intranucleotide interactions make the left B-DNA unfavourable while the left C-DNA structure is more stable, for all the sequences, than the right C-DNA structure, proposed from fibre data. For the hexanucleoside pentaphosphate fragments the same trend is observed, with the right handed B-DNA being the most stable of the four models studied. However, the left C-DNA structure is only marginally higher in energy, particularly if the shielding effect of the counter ions, on the phosphate group is taken into consideration.     

Energetics of Left and Right Handed Models of DNA

Abstract

It has been shown by model building studies that various right handed and left handed models are compatible with X-ray data of B-DNA and C-DNA. These models are also found to be in good agreement with infrared dichroism data. Detailed potential energy calculations have now been carried out for these models, viz., right and left handed B-DNA and right and left handed C-DNA It is found that base sugar stacking and interactions involving the phosphate groups are the dominant force s for stabilizing a particular structure. For some sequences, viz., A-A, T-A and C-A, left handed stacking is quite favourable in both B and C structures. But intranucleotide interactions make the left B-DNA unfavourable while the left C-DNA structure is more stable, for all the sequences, than the right C-DNA structure, proposed from fibre data. For the hexanucleoside pentaphosphate fragments the same trend is observed, with the right handed B-DNA being the most stable of the four models studied. However, the left C-DNA structure is only marginally higher in energy, particularly if the shielding effect of the counter ions, on the phosphate group is taken into consideration.     

Bilateral asymmetry in bone measurements of the hand and lateral hand dominance

Two hundred thirty–five (235) normal male participants of the Baltimore Longitudinal Study were classified as right handed, left handed, and ambidextrous on the basis of their grip–strength performance. Their left and right hands were also radiographed and the measurements of the second metacarpal bones were evaluated on the basis of hand dominance. The results indicated that, as a rule, the right hand measurements are higher than those of the left hand, regardless of hand dominance. The bilateral differences in total width, length, total area and cortical area are significant among the right hand dominant and nonsignificant among the left hand dominant. Regardless off hand dominance the bilateral differences in medullary width are nonsignificant. These results suggest an inherent tendency of the right second metacarpal to have more bone than the left regardless of hand dominance. Differential stress due to hand dominance will increase the bilateral difference in the right handed and reduce it in the left handed.     

Right‐ and left‐handed three‐helix proteins. I. Experimental and simulation analysis of differences in folding and structure

Despite the large number of publications on three‐helix protein folding, there is no study devoted to the influence of handedness on the rate of three‐helix protein folding. From the experimental studies, we make a conclusion that the left‐handed three‐helix proteins fold faster than the right‐handed ones. What may explain this difference? An important question arising in this paper is whether the modeling of protein folding can catch the difference between the protein folding rates of proteins with similar structures but with different folding mechanisms. To answer this question, the folding of eight three‐helix proteins (four right‐handed and four left‐handed), which are similar in size, was modeled using the Monte Carlo and dynamic programming methods. The studies allowed us to determine the orders of folding of the secondary‐structure elements in these domains and amino acid residues which are important for the folding. The obtained data are in good correlation with each other and with the experimental data. Structural analysis of these proteins demonstrated that the left‐handed domains have a lesser number of contacts per residue and a smaller radius of cross section than the right‐handed domains. This may be one of the explanations of the observed fact. The same tendency is observed for the large dataset consisting of 332 three‐helix proteins (238 right‐ and 94 left‐handed). From our analysis, we found that the left‐handed three‐helix proteins have some less‐dense packing that should result in faster folding for some proteins as compared to the case of right‐handed proteins.Proteins 2013; © 2013 Wiley Periodicals, Inc.     

Lateralized Turning Biases in Two Neotropical Tadpoles

Lateralized turning behavior in startle responses and upon descent after surfacing for a breath of air has been documented for tadpoles in several anuran species. A left‐handed preference is most common and was previously thought to be linked to the asymmetry in spiracle location. Here, we investigate the presence of behavioral asymmetries in tadpoles of Agalychnis callidryas and Leptodactylus melanonotus in explosive turns after air‐breathing. Data were also collected on lateralized posture in the orientation of tails of embryonic A. callidryas within the egg case, as well as the startle response of free‐swimming tadpoles exposed to mechanical stimulation. A left‐curled tail bias was found among several clutches from Costa Rica, but this was not the case among clutches examined from Panama. Free‐living tadpoles of L. melanonotus displayed a distinct right‐handed preference during explosive turns. While some tadpoles of A. callidryas were at stages too early to detect any explosive turns when breathing, later‐staged individuals did display a left‐handed bias in startle response to mechanical stimulation. Additionally, it appears that the expression of behavioral lateralization of larvae (but not embryos) may predict whether or not the adults exhibit similar lateralization. Findings herein provide insight into the ontogeny and evolutionary origins of lateralized behavior in anurans.     

Right‐handed fossil humans

Fossil hominids often processed material held between their upper and lower teeth. Pulling with one hand and cutting with the other, they occasionally left impact cut marks on the lip (labial) surface of their incisors and canines. From these actions, it possible to determine the dominant hand used. The frequency of these oblique striations in an array of fossil hominins documents the typically modern pattern of 9 right‐ to 1 left‐hander. This ratio among living Homo sapiens differs from that among chimpanzees and bonobos and more distant primate relatives. Together, all studies of living people affirm that dominant right‐handedness is a uniquely modern human trait. The same pattern extends deep into our past. Thus far, the majority of inferred right‐handed fossils come from Europe, but a single maxilla from a Homo habilis, OH‐65, shows a predominance of right oblique scratches, thus extending right‐handedness into the early Pleistocene of Africa. Other studies show right‐handedness in more recent African, Chinese, and Levantine fossils, but the sample compiled for non‐European fossil specimens remains small. Fossil specimens from Sima del los Huesos and a variety of European Neandertal sites are predominately right‐handed. We argue the 9:1 handedness ratio in Neandertals and the earlier inhabitants of Europe constitutes evidence for a modern pattern of handedness well before the appearance of modern Homo sapiens.     

Designing of peptides with left handed helical structure by incorporating the unusual amino acids

The conformational behaviour of delta Ala has been investigated by quantum mechanical method PCILO in the model dipeptide Ac-delta Ala-NHMe and in the model tripeptides Ac-X-delta Ala-NHMe with X = Gly, Ala, Val, Leu, Abu and Phe and is found to be quite different. The computational results suggest that in the model tripeptides the most stable conformation corresponds to phi 1 = -30 degrees, psi 1 = 120 degrees and phi 2 = psi 2 = 30 degrees in which the > C = 0 of the acetyl group is involved in hydrogen bond formation with N-H of the amide group. Similar results were obtained for the conformational behaviour of D-Ala in Ac-D-Ala-NHMe and Ac-Ala-D-Ala-NHMe. The conformational behaviour of the amino acids delta Ala, D-Ala, Val and Aib in model tripeptides have been utilized in the designing of left handed helical peptides. It is shown that the peptide HCO-(Ala-D-Ala)3-NHMe can adopt both left and right handed helix whereas in the peptide Ac-(Ala-delta Ala)3-NHMe the lowest energy conformer is beta-bend ribbon structure. Left handed helical structure with phi = 30 degrees, psi = 60 degrees for D-Ala residues and phi = psi = 30 degrees for delta Ala is found to be more stable by 4 kcal mole-1 than the corresponding right handed helical structure for the peptide Ac-(D-Ala-delta Ala)3-NHMe. In both the peptides Ac-(Val-delta Ala)3-NHMe and Ac-(D-Val-delta Ala)3-NHMe the most stable conformer is the left handed helix. Comparisons of results for Ac-(Ala-delta Ala)3-NHMe and Ac(Val-delta Ala)3-NHMe and Ac-(D-Ala-delta Ala)3-NHMe and Ac-(D-Val-delta Ala)3-NHMe also reveal that the Val residues facilitate the population of 3(10) left handed helix over the other conformers. It is also shown that the conformational behaviour of Aib residue depends on the chirality of neighbouring amino acids, i.e. Ac-(Aib-Ala)3-NHMe adopts right handed helical structure whereas Ac-(Aib-D-Ala)3-NHMe is found to be in left handed helical structure.     

Conformational Studies of β-glucans

Steric and energy contour diagrams have been plotted for disaccharide-like and for helical structures of linear β-D -glucans having (1 → 2), (1 → 3) and (1 → 4) linkages. The allowed conformations constitute only about. 4% of the total conformations, indicating that the freedom of rotation of glucose residues is highly restricted in all the three polysaccharides. The additional restrictions of the monomer unit, as one passes from disaccharide to polysaccaride structures, are severe in the case of (1 → 2) and (1 → 3) linked polysaccharides but not in (1 → 4) linked polysaccharide. The difference in the nature of linkages also has shown to affect the energetically preferred conformations: (1 → 2) linkages lead only to left handed helical conformations; (1 → 3) linkages lead to both right and left handed wide and extended helical conformations, (1 → 4) linkages lead to both right and left handed extended helical conformations. The possible hydrogen bonds between adjacent residues are also dependent on the nature of linkage.     

Prevalence of the three categories of handedness among Malawian school children

A cross sectional study of prevalence of left, right and mixed handedness was made on 512 Malawian school children (240 boys and 272 girls) aged 6-17 years. Handedness was assessed using questionnaire incorporating questions on hand preferred for eight unimanual activities. Interviews with guardians, pupils and teachers were conducted to assess the pressure experienced by children to use right hand for unimanual activities. The overall prevalence of left-, right- and mixed-handers was 3.9%, 90.4% and 5.7%, respectively. Association between handedness and age or gender of children was nonsignificant. 96.2% of guardians and 92.7% of teachers were insistent upon use of right hand for unimanual tasks. Most of non-right handed children indicated that they had experienced pressure to use right hand for unimanual activities but they were still using left hand for one or more manual tasks. 28 pupils indicated that they stopped using left hand under the pressure from guardians and teachers.     

Terminal effect of chiral residue on helical screw sense in achiral peptides

To understand the terminal effect of chiral residue for determining a helical screw sense, we adopted five kinds of peptides I – V containing N‐ and/or C‐terminal chiral Leu residue(s): Boc–L ‐Leu–(Aib–ΔPhe)₂–Aib–OMe ( I ), Boc–(Aib–ΔPhe)₂–L ‐Leu–OMe ( II ), Boc–L ‐Leu–(Aib–ΔPhe)₂–L ‐Leu–OMe ( III ), Boc–D ‐Leu–(Aib–ΔPhe)₂–L ‐Leu–OMe ( IV ), and Boc–D ‐Leu–(Aib–ΔPhe)₂–Aib–OMe ( V ). The segment –(Aib–ΔPhe)₂– was used for a backbone composed of two “enantiomeric” (left‐/right‐handed) helices. Actually, this could be confirmed by ¹H‐nmr [nuclear Overhauser effect (NOE) and solvent accessibility of NH resonances] and CD spectroscopy on Boc–(Aib–ΔPhe)₂–Aib–OMe, which took a left‐/right‐handed 3₁₀‐helix. Peptides I – V were also found to take 3₁₀‐type helical conformations in CDCl₃, from difference NOE measurement and solvent accessibility of NH resonances. Chloroform, acetonitrile, methanol, and tetrahydrofuran were used for CD measurement. The CD spectra of peptides I – III in all solvents showed marked exciton couplets with a positive peak at longer wavelengths, indicating that their main chains prefer a left‐handed screw sense over a right‐handed one. Peptide V in all solvents showed exciton couplets with a negative peak at longer wavelengths, indicating it prefers a right‐handed screw sense. Peptide IV in chloroform showed a nonsplit type CD pattern having only a small negative signal around 280 nm, meaning that left‐ and right‐handed helices should exist with almost the same content. In the other solvents, peptide IV showed exciton couplets with a negative peak at longer wavelengths, corresponding to a right‐handed screw sense. From conformational energy calculation and the above ¹H‐nmr studies, an N‐ or C‐terminal L ‐Leu residue in the lowest energy left‐handed 3₁₀‐helical conformation was found to take an irregular conformation that deviates from a left‐handed helix. The positional effect of the L ‐residue on helical screw sense was discussed based on CD data of peptides I – V and of Boc–(L ‐Leu–ΔPhe)_n–L ‐Leu–OMe (n = 2 and 3). © 1999 John Wiley & Sons, Inc. Biopoly 49: 551–564, 1999     

Family history interview of a broad phenotype in specific language impairment and matched controls

The aim was to study a broader phenotype of language‐related diagnoses and problems in three generations of relatives of children with specific language impairment (SLI). Our study is based on a family history interview of the parents of 59 children with SLI and of 100 matched control children, exploring the prevalence of problems related to language, reading, attention, school achievement and social communication as well as diagnoses such as attention‐deficit hyperactivity disorder (ADHD), autism, Asperger syndrome, dyslexia, mental retardation, cleft palate and stuttering. The results show a spectrum of language‐related problems in families of SLI children. In all three generations of SLI relatives, we found significantly higher prevalence rates of language, literacy and social communication problems. The risk of one or both parents having language‐related diagnoses or problems was approximately six times higher for the children with SLI (85%) than for the control children (13%) (odds ratio = 37.2). We did not find a significantly higher prevalence of the diagnoses ADHD, autism or Asperger syndrome in the relatives of the children with SLI. However, significantly more parents of the children with SLI had problems with attention/hyperactivity when compared with the parents of controls. Our findings suggest common underlying mechanisms for problems with language, literacy and social communication, and possibly also for attention/hyperactivity symptoms.     

Studies on the prevalence of tinea capitis infection in Ile-Ife,Nigeria

Investigations were carried out into the prevalence of tinea capitis infection among school children in Ile-Ife, Nigeria. The prevalence rate of clinical infection was found to be 14.02%. The infection was found to be more frequent among pupils between ages 5 and 10 years, and more prevalent among the poor than the rich (p<0.005). Families having between 1 and 4 children had lower prevalence than families having minimum of five children (p<0.10). Approximately one-third of the clinically infected children were not receiving any treatment while about two-thirds of the remaining two-thirds were using local native remedies, some of which had resulted in deaths of some children. The most common causative agent isolated from the lesions was Microsporum audouinii.     

婴儿腹痛与家族性偏头痛的相关性研究

目的:研究家族性偏头痛对婴儿腹痛的影响及其相关性。方法:112例婴儿腹痛患儿为腹痛组,97例同期就诊非婴儿腹痛及头痛患儿为对照组,对所有患儿的一、二级及三级亲属进行问卷调查,然后对有偏头痛的亲属用统一的标准进行诊断,最后对两组患儿及其亲属的发病率进行对比分析。结果:20例(17.86%)婴儿腹痛患儿有家族性偏头痛,对照组6例(6.19%)患儿有家族性偏头痛,家族性患偏头痛的患儿比例在两组之间有显著差异(P<0.05);婴儿腹痛患儿的亲属诊断为偏头痛有85例,占本组调查总人数的16.93%,对照组患儿偏头痛亲属共有17例,占调查总人数的2.37%,两组患儿亲属患偏头痛的发病率有显著差异(P<0.05);患儿亲属患偏头痛种类的比较:腹痛组有家族性偏瘫型偏头痛和儿童腹型偏头痛,对照组没有;除散发性偏瘫型偏头痛的在两组的差异有统计学意义(P<0.05),其他种类的偏头痛没有显著差异。结论:有家族性偏头痛史的婴儿腹痛发生率高于正常人,婴儿腹痛与家族性偏头痛的发生率相关,与偏头痛的种类也可能有关。     

An intervention study to increase knowledge and use of folic acid among relatives in neural tube defect-affected families in Washington, D.C

BACKGROUND: Little is known about the level of knowledge and use of folic acid among near relatives in U.S. families of a child with spina bifida. We hypothesized that relatives would be more knowledgeable than the general population and more likely to take folic acid. Further, we hypothesized that relatives would be more motivated by an intervention to increase their use of folic acid. METHODS: We conducted an intervention study among females in families attending a hospital spina bifida clinic in Washington, DC. RESULTS: The 231 subjects consisted of the affected individuals, mothers, sisters, and aunts. The average age was 34 years. At baseline, most (87.4%) reported that they had heard of folic acid; 37.6% were currently taking multivitamins with folic acid and 6.9% were taking folic acid tablets. The intervention significantly increased both knowledge (to 99%) and intake of folic acid from 41.9 to 48.5%. Folic acid intake increased significantly among African-American women and women with less education, women who were older, married, with children, and nonsmokers. CONCLUSIONS: This intervention was successful in increasing folic acid intake among female relatives in spina bifida-affected families. By the end of the study, almost all women had heard of folic acid and folic acid use had increased by 16%. Among these women at higher than expected risk for having an affected child, this rate of intake, while more than the general population, still falls short of optimum. Fortification of food with folic acid may be the only way to ensure increased folic acid intake.     

Actigraphic Investigations On The Activity‐Rest Behavior Of Right‐ and Left‐Handed Students

The aim of this study was to explore differences between left‐and right‐handed subjects in sleep duration. Sleep and activity patterns were continuously registered for 12 days using actometers on 20 left‐handed and 20 right‐handed medical students in Berlin. Handedness was determined by a modified version of the Edinburgh handedness inventory. Each participant wore one actometer on each wrist. Actiwatch® Sleep Analysis Software (CNT, UK) was used to evaluate the data, and statistical calculations were performed with a non‐parametric variance analysis. A significant difference in mean sleep duration between left‐handers (7.9 h) and right‐handers (7.3 h) was determined (p=0.025 for measurement made on the dominant hand and p=0.013 for ones made on the non‐dominant hand). In contrast, the maximal phase of daily activity (acrophase) did not show any difference between the two groups. The difference in sleep duration might be caused by either the greater effort required for left‐handers to cope in a right‐handed world or by structural brain differences.     

“One feels anger to know there is no one to help us!”. Perceptions of mothers of children with Zika virus-associated microcephaly in Caribbean Colombia: A qualitative study

BackgroundThe epidemic of Zika virus (ZIKV) was associated with a sudden and unprecedented increase in infants born with microcephaly. Colombia was the second most affected country by the epidemic in the Americas. Primary caregivers of children with ZIKV-associated microcephaly, their mothers mainly, were at higher risk of suffering anxiety and depression. Often, these women were stigmatized and abandoned by their partners, relatives, and communities.Methodology/Principal findingsThis study aimed to understand the perceptions about ZIKV infection among mothers of children born with microcephaly during the ZIKV epidemic in Caribbean Colombia, and the barriers and facilitators affecting child health follow-up. An exploratory qualitative study, based on Phenomenology and Grounded Theory, was conducted in Caribbean Colombia. Data were collected through In-Depth Interviews (IDI) from women who delivered a baby with microcephaly during the ZIKV epidemic at Clínica Salud Social, Sincelejo, Sucre District (N = 11). The themes that emerged during the interviews included experiences from their lives before pregnancy; knowledge about ZIKV; experiences and perceptions when diagnosed; considering a possible termination of pregnancy, and children’s clinical follow-up. In some cases, women reported having been told they were having a baby with microcephaly but decided not to terminate the pregnancy; while in other cases, women found out about their newborn’s microcephaly condition only at birth. The main barriers encountered by participants during children’s follow-up included the lack of psychosocial and economic support, the stigmatization and abandonment by some partners and relatives, and the frustration of seeing the impaired development of their children.ConclusionsThis study contributed to identifying the social, medical, psychological, and economic needs of families with children affected by the ZIKV epidemic. Commitment and action by local and national governments, and international bodies, is required to ensure sustained and quality health services by affected children and their families.     

Children with 4q-syndrome: the parents' perspective

A questionnaire survey was conducted among the parents of 32 not previously described children with 4q-syndrome, and 4 affected adult relatives. The questions related to the medical condition of the individual child and the interactions between parents and health professionals. The response rate of the survey was 58 %, and the mean age of the patients was 11.2 years. Thirty eight percent of children were diagnosed within the 1st month of life. Most parents felt severely distressed at the time of diagnosis and 66 % complained about a lack of medical information made available to them. However, parental understanding of the genetic aetiology responsible for the 4q-syndrome was overall good. Apart from a multidisciplinary team of healthcare workers, the internet and religion were named as sources of support. In all, 86 % of parents valued the experience of having a child with 4q-syndrome highly despite the difficulties involved.     

Right‐ and left‐handed three‐helix proteins. II. Similarity and differences in mechanical unfolding of proteins

Here, we study mechanical properties of eight 3‐helix proteins (four right‐handed and four left‐handed ones), which are similar in size under stretching at a constant speed and at a constant force on the atomic level using molecular dynamics simulations. The analysis of 256 trajectories from molecular dynamics simulations with explicit water showed that the right‐handed three‐helix domains are more mechanically resistant than the left‐handed domains. Such results are observed at different extension velocities studied (192 trajectories obtained at the following conditions: v = 0.1, 0.05, and 0.01 Å ps^?1, T = 300 K) and under constant stretching force (64 trajectories, F = 800 pN, T = 300 K). We can explain this by the fact, at least in part, that the right‐handed domains have a larger number of contacts per residue and the radius of cross section than the left‐handed domains. Proteins 2014; 82:90–102. © 2013 Wiley Periodicals, Inc.     

Median frequency of the myoelectric signal. Effects of hand dominance

A study was performed to investigate the existence of any distinction in the fatiguability of corresponding contralateral muscles in the hand as a function of hand dominance. The first dorsal interosseous muscle was studied. The median frequency of the myoelectric signal was employed to describe the fatigue behavior of the muscle. It was found that during sustained contractions the median frequency decreased faster in the non-dominant hand of right handed individuals, whereas, no statistically significant distinction could be found in left handed individuals. This distinction was evident in both male and female subjects. This study demonstrates that continued preferential usage of a muscle is associated with altered electrical properties of the myoelectric signal and that the median frequency of the signal provides an appropriate measure of the modifications. It is argued that the findings may provide an indication of modifications in the metabolic properties of muscle fibers induced by a lifetime of preferred functional use.