bluuebunny/crossref_metadata_2025 huggingface dataset:
Infrared signatures of the peptide dynamical transition: A molecular dynamics simulation study
Authors: Kobus Maja , Nguyen Phuong H. , Stock Gerhard
Published: July 2010

Recent two-dimensional infrared (2D-IR) experiments on a short peptide 310-helix in chloroform solvent [E. H. G. Backus et al., J. Phys. Chem. B 113, 13405 (2009)] revealed an intriguing temperature dependence of the homogeneous line width, which was interpreted in terms of a dynamical transition of the peptide. To explain these findings, extensive molecular dynamics simulations at various temperatures were performed in order to construct the free energy landscape of the system. The study recovers the familiar picture of a glass-forming system, which below the glass transition temperature Tg is trapped in various energy basins, while it diffuses freely between these basins above Tg. In fact, one finds at Tg≈270 K a sharp rise of the fluctuations of the backbone dihedral angles, which reflects conformational transitions of the peptide. The corresponding CO frequency fluctuations are found to be a sensitive probe of the peptide conformational dynamics from femtosecond to nanosecond time scales and lead to 2D-IR spectra that qualitatively match the experiment. The calculated homogeneous line width, however, does not show the biphasic temperature dependence observed in experiment.
Terahertz activated luminescence of trapped carriers in InGaAs/GaAs quantum dots
Authors: Bhattacharyya J. , Wagner M. , Helm M. , Hopkinson M. , Wilson L. R. , Schneider H.
Published: July 2010

Optical properties and interdot transfer dynamics of trapped carriers in InGaAs quantum dots (QDs) are investigated. Time resolved photoluminescence (PL) was measured for time-delayed interband and intraband excitations. Terahertz activated luminescence (TAL) from trapped carriers having lifetimes of ∼250 ns at 8 K, was observed. Spectral shift of the TAL with respect to the PL showed the trionic nature of the PL in the n-doped QDs. With increasing terahertz excitation intensity, the TAL increased and reached saturation. The activation energy associated with the trapped carrier decay was quite close to the intersublevel transition energy (∼20 meV) indicating trapping in the QDs.
Trade-off between density of states and gate capacitance in size-dependent injection velocity of ballistic n-channel silicon nanowire transistors
Authors: Lee Yeonghun , Kakushima Kuniyuki , Shiraishi Kenji , Natori Kenji , Iwai Hiroshi
Published: July 2010

We carried out a comprehensive study on the impact of size-dependent subband structures on the ballistic silicon nanowire transistors. One of the prominent features was that the injection velocity could be improved, owing to the increase in the source Fermi level measured from the conduction band edge. Moreover, because of the trade-off between the density of states and the gate capacitance, the source Fermi level showed a peak, indicating the optimum wire size for a field-effect transistor. Finally, our results revealed that this trade-off relationship as a feature in nanowire transistors should be considered for the size-dependent performance assessment.
Parallel spin filling and energy spectroscopy in few-electron Si metal-on-semiconductor-based quantum dots
Authors: Xiao M. , House M. G. , Jiang H. W.
Published: July 2010

We report the spin filling pattern in the few electron limit of silicon metal-on-semiconductor based quantum dots (QDs). Magnetic field dependence of Coulomb oscillation peaks showed filling of parallel spins for the last few electrons. This implies the existence of a large spin exchange energy compared with the orbital level spacing, which has been predicted for relatively large silicon QDs. Our excited-state spectroscopy study confirmed a large spin exchange energy, as well as a large valley splitting at zero magnetic field.
Organic electrochemical light emitting field effect transistors
Authors: Yumusak C. , Sariciftci N. S.
Published: July 2010

We report on the demonstration of an organic electrochemical light emitting field effect transistor. The device fabricated in bottom gate/bottom contact geometry using a conjugated polymer poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) mixed with polymer electrolyte poly(ethylene oxide) including lithium trifluoromethanesulfonate (Li triflate) as active layer and poly(vinyl alcohol) as gate dielectric. Orange-yellow light emission is observed from the device. The output characteristics (source-drain current versus the source-drain voltage) and transfer characteristics (source-drain current versus the gate voltage) of the device are reported.
Intrinsic geometric scattering probed by picosecond optoacoustics in a cylindrical cavity: Application to acoustic and optical characterizations of a single micron carbon fiber
Authors: Ségur D. , Guillet Y. , Audoin B.
Published: July 2010

A picosecond pump-probe technique is used to reveal the optoacoustic response of a single micrometric carbon fiber. The signature of the intrinsic geometric scattering resulting from acoustic reflections at free surface of the cylindrical cavity is contained in the signals. The fiber transverse elastic properties and the fiber complex refractive index at 796 nm are measured nondestructively.
Electric field distribution in AlGaN/GaN high electron mobility transistors investigated by electroluminescence
Authors: Simms R. J. T. , Gao F. , Pei Y. , Palacios T. , Mishra U. K. , Kuball M.
Published: July 2010

Electric field distributions in AlGaN/GaN high electron mobility transistors have been assessed by studying electroluminescence and its spatial intensity distribution. Three gate architectures were compared: (i) standard gate, (ii) slant gate, and (iii) recessed slant gate with fluorination. It was found that differences in peak electric field strengths between devices, determined using electroluminescence, agreed well with simulations. However, recessed slant gate devices with fluorination exhibited a spread of electroluminescence intensity and therefore electric field distribution toward the drain contact by 0.2–0.3 μm which was not predicted by simulation. Implication of the disagreement between measured and simulated electric field distribution are discussed.
Role of oxygen incorporation in electronic properties of rubrene films
Authors: Song Xin , Wang Li , Fan Qitang , Wu Yuyu , Wang Hongming , Liu Chunmei , Liu Nianhua , Zhu Junfa , Qi Dongchen , Gao Xingyu , Wee Andrew T. S.
Published: July 2010

The electronic properties of rubrene films exposed to oxygen have been studied by photoemission and x-ray absorption spectroscopies. Oxygen incorporation causes the highest occupied molecular orbital of rubrene to shift to a ∼1.0 eV deep level due to chemical bonds formed by the oxygen atoms with the carbon atoms within the tetracene backbone of rubrene molecules. Deformation of the molecular backbone induced by the C–O bonds destroys the delocalized nature of the molecular orbitals. The oxidized rubrene molecules in a single crystal are proposed to act as point defects that disturb the long-range periodicity and produce localized acceptor states.
Reflection high-energy electron diffraction ϕ scans for in situ monitoring the heteroepitaxial growth of Fe on GaN(0001) by molecular beam epitaxy
Authors: Gao Cunxu , Schönherr Hans-Peter , Brandt Oliver
Published: July 2010

The heteroepitaxial growth of Fe films on GaN(0001) by molecular beam epitaxy is monitored in situ by reflection high-energy electron diffraction ϕ scans. The complex epitaxial orientation-relationship between Fe and GaN can be visualized by these ϕ scans already at an Fe coverage of two monolayers. By comparing the data to ex situ x-ray ϕ scans, we show that these measurements even allow a quantitative determination of the in-plane orientation-distribution of the heteroepitaxial film. The orientation-distribution is minimized for a growth temperature of 350 °C.
Reproductive biology of Melaleuca alternifolia (Myrtaceae) 2. Incompatibility and pollen transfer in relation to the breeding system
Authors: Baskorowati L. , Moncur M. W. , Cunningham S. A. , Doran J. C. , Kanowski P. J.
Published: July 2010

The onset of stigma receptivity in Melaleuca alternifolia (Maiden & Betche) Cheel was evaluated by observing pollen-tube growth and seed set following controlled pollination. Pollen-tube numbers in the style, following controlled pollinations, increased from Day 1 to Day 6, then declining rapidly. The stigma was most receptive during Days 3–6, and still receptive at low levels as early as shortly after anthesis and as late as 10 days after pollination. The present study found that individuals of M. alternifolia differed in their degree of expression of self-incompatibility. Artificial self-pollination, with emasculation, in several families resulted in complete self-incompatibility, with no capsule retention. The microscopic observation of pollen-tube development revealed a mechanism of self-incompatibility in M. alternifolia. A self-incompatibility system operates in the style, although a few self-pollen grains are capable of germinating and producing pollen tubes. It also appears that late-acting self-incompatibility mechanisms discriminate against self-pollen tubes when they descend to the ovary. Artificial cross-pollination of selected parents produced seed with greater germination capacity and seedlings that grew faster than the corresponding open-pollinated seed and seedlings from the same parent. Freeze-dried pollen stored at −18°C maintained viability (22%) over 1 year of storage. This finding will allow greater flexibility in undertaking controlled pollinations, because stored pollen can be substituted for fresh pollen when insufficient quantities are available from new-season flowers. A wide variety of insects was observed visiting the flowers of M. alternifolia, and capsule set was high even in bags that excluded flower visitors greater than 2 mm. Thrips species seem likely to be important pollinators of this species because they are small and were abundant inside and outside of exclusion bags, although several other insect species such as bees, flies and wasps were also identified as frequent floral visitors.
Policies for reduced deforestation and their impact on agricultural production
Authors: Angelsen Arild
Published: July 2010

Policies to effectively reduce deforestation are discussed within a land rent (von Thünen) framework. The first set of policies attempts to reduce the rent of extensive agriculture, either by neglecting extension, marketing, and infrastructure, generating alternative income opportunities, stimulating intensive agricultural production or by reforming land tenure. The second set aims to increase either extractive or protective forest rent and—more importantly—create institutions (community forest management) or markets (payment for environmental services) that enable land users to capture a larger share of the protective forest rent. The third set aims to limit forest conversion directly by establishing protected areas. Many of these policy options present local win–lose scenarios between forest conservation and agricultural production. Local yield increases tend to stimulate agricultural encroachment, contrary to the logic of the global food equation that suggests yield increases take pressure off forests. At national and global scales, however, policy makers are presented with a more pleasant scenario. Agricultural production in developing countries has increased by 3.3–3.4% annually over the last 2 decades, whereas gross deforestation has increased agricultural area by only 0.3%, suggesting a minor role of forest conversion in overall agricultural production. A spatial delinking of remaining forests and intensive production areas should also help reconcile conservation and production goals in the future.
Microhomology-mediated and nonhomologous repair of a double-strand break in the chloroplast genome of
Arabidopsis
Authors: Kwon Taegun , Huq Enamul , Herrin David L.
Published: July 2010

Chloroplast DNA (cpDNA) is under great photooxidative stress, yet its evolution is very conservative compared with nuclear or mitochondrial genomes. It can be expected that DNA repair mechanisms play important roles in cpDNA survival and evolution, but they are poorly understood. To gain insight into how the most severe form of DNA damage, a double-strand break (DSB), is repaired, we have developed an inducible system in
Arabidopsis
that employs a
psbA
intron endonuclease from
Chlamydomonas
, I-CreII, that is targeted to the chloroplast using the rbcS1 transit peptide. In
Chlamydomonas
, an I-CreII-induced DSB in
psbA
was repaired, in the absence of the intron, by homologous recombination between repeated sequences (20–60 bp) abundant in that genome;
Arabidopsis
cpDNA is very repeat poor, however. Phenotypically strong and weak transgenic lines were examined and shown to correlate with I-CreII expression levels. Southern blot hybridizations indicated a substantial loss of DNA at the
psbA
locus, but not cpDNA as a whole, in the strongly expressing line. PCR analysis identified deletions nested around the I-CreII cleavage site indicative of DSB repair using microhomology (6–12 bp perfect repeats, or 10–16 bp with mismatches) and no homology. These results provide evidence of alternative DSB repair pathways in the
Arabidopsis
chloroplast that resemble the nuclear, microhomology-mediated and nonhomologous end joining pathways, in terms of the homology requirement. Moreover, when taken together with the results from
Chlamydomonas
, the data suggest an evolutionary relationship may exist between the repeat structure of the genome and the organelle's ability to repair broken chromosomes.
Unipolar assembly of zinc oxide rods manifesting polarity-driven collective luminescence
Authors: Gautam Ujjal K. , Imura Masataka , Rout Chandra Sekhar , Bando Yoshio , Fang Xiaosheng , Dierre Benjamin , Sakharov Leonid , Govindaraj A. , Sekiguchi Takashi , Golberg Dmitri , Rao C. N. R.
Published: July 2010

Oriented assemblies of small crystals forming larger structures are common in nature and crucial for forthcoming technologies as they circumvent the difficulties of structural manipulation at microscopic scale. We have discovered two distinctive concentric assemblies of zinc oxide rods, wherein each rod has an intrinsically positive and a negative polar end induced by the noncentrosymmetric arrangement of Zn and O atoms. All the rods in a single assembly emanate out of a central core maintaining a single polar direction. Due to growth along the two polar surfaces with different atomic arrangements, these assemblies are distinct in their intrinsic properties and exhibit strong UV luminescence in the exterior of Zn-polar assemblies, unlike the O-polar assemblies. Although novel applications can be envisioned, these observations suggest that hierarchical organization with respect to internal asymmetry might be widespread in natural crystal assemblies.
Single-cell mechanics provides a sensitive and quantitative means for probing amyloid-β peptide and neuronal cell interactions
Authors: Lulevich Valentin , Zimmer Christopher C. , Hong Hyun-seok , Jin Lee-way , Liu Gang-yu
Published: July 2010

By using a highly sensitive technique of atomic force microscopy-based single-cell compression, the rigidity of cultured N2a and HT22 neuronal cells was measured as a function of amyloid-β42 (Aβ42) protein treatment. Aβ42 oligomers led to significant cellular stiffening; for example, 90–360% higher force was required to reach 80% deformation for N2a cells. Disaggregated or fibrillar forms of Aβ42 showed much less change. These observations were explained by a combination of two factors: (i) incorporation of oligomer into cellular membrane, which resulted in an increase in the Young's modulus of the membrane from 0.9 ± 0.4 to 1.85 ± 0.75 MPa for N2a cells and from 1.73 ± 0.90 to 5.5 ± 1.4 MPa for HT22 cells, and (ii) an increase in intracellular osmotic pressure (e.g., from 7 to 40 Pa for N2a cells) through unregulated ion influx. These findings and measurements provide a deeper, more characteristic, and quantitative insight into interactions between cells and Aβ42 oligomers, which have been considered the prime suspect for initiating neuronal dysfunction in Alzheimer's disease.
Spiny frogs (Paini) illuminate the history of the Himalayan region and Southeast Asia
Authors: Che Jing , Zhou Wei-Wei , Hu Jian-Sheng , Yan Fang , Papenfuss Theodore J. , Wake David B. , Zhang Ya-Ping
Published: July 2010

Asian frogs of the tribe Paini (Anura: Dicroglossidae) range across several first-order tectono-morphological domains of the Cenozoic Indo-Asian collision that include the Tibetan Plateau, the Himalayas, and Indochina. We show how the tectonic events induced by the Indo-Asian collision affected the regional biota and, in turn, how the geological history of the earth can be viewed from a biological perspective. Our analysis of a concatenated dataset comprising four nuclear gene sequences of Paini revealed two main radiations, corresponding to the genera
Nanorana
(I) and
Quasipaa
(II). Five distinct clades are recognized: Tibetan plateau clade (I-1), Himalaya clade (I-2), environs of Himalaya–Tibetan plateau clade (I-3), South China clade (II-1), and Indochina clade (II-2). This pattern of relationships highlights the significance of geography in shaping evolutionary history. Building on our molecular dating, ancestral region reconstruction, and distributional patterns, we hypothesize a distinct geographic and climatic transition in Asia beginning in the Oligocene and intensifying in the Miocene; this stimulated rapid diversification of Paini. Vicariance explains species formation among major lineages within
Nanorana
. Dispersal, in contrast, plays an important role among
Quasipaa
, with the southern Chinese taxa originating from Indochina. Our results support the tectonic hypothesis that an uplift in the Himalaya–Tibetan plateau region resulting from crustal thickening and lateral extrusion of Indochina occurred synchronously during the transition between Oligocene and Miocene in reaction to the Indo-Asian collision. The phylogenetic history of Paini illuminates critical aspects of the timing of geological events responsible for the current geography of Southeast Asia.
Repetitive but not redundant
Authors: Leslie Mitch
Published: July 2010

Satellite DNA found at centromeres promotes correct spindle–chromosome attachments.
Infection Control in Field Hospitals after a Natural Disaster: Lessons Learned after the 2010 Earthquake in Haiti
Authors: Lichtenberger Paola , Miskin Ian N. , Dickinson Gordon , Schwaber Mitchell J. , Ankol Omer E. , Zervos Marcus , Campo Rafael E. , Doblecki-Lewis Susanne , Déry Mark Alain , Munoz-Price L. Silvia
Published: July 2010

After the January 12, 2010, earthquake in Haiti, Project Medishare and the University of Miami organized, built, and staffed a 200-bed field hospital (the University of Miami Hospital in Haiti [UMHH] ) on the outskirts of Port-au-Prince. We describe the operational challenges of providing a safe environment at the UMHH. Furthermore, we compared how these issues were addressed at this ad hoc hospital with how they were addressed at the field hospital of the Israel Defense Force, a fully deployable hospital with an organization fine-tuned as a result of prior disaster situations, also in Haiti.
Burns in young children: a retrospective matched cohort study of health and developmental outcomes
Authors: Hutchings H. , Barnes P. M. , Maddocks A. , Lyons R. , James‐Ellison M. Y.
Published: July 2010

Background  Unintentional injuries are a major cause of death and disability in childhood. Most burns are unintentional, the majority occurring in pre‐school children. Little is known about the outcomes of young children following burns. The purpose of this study was to examine the presenting features of burned children and compare their health and developmental outcomes with controls.

Methods  Children under 3 years admitted to the Welsh Regional Burns Centre between September 1994 and August 1997 were studied up to their sixth birthday (final data collection 2003) to ascertain the nature, course and cause of their burn. One hundred and forty‐five burned children were matched with 145 controls. Their physical, psychosocial and educational health status was compared. Retrospective data were gathered from hospital notes, social services, emergency department databases, child health surveillance records and schools.

Results  Burns peaked at age 13–18 months were typically sustained by scalding, drink spillage and contact with hot objects. They occurred most frequently at mealtimes and 89.7% were judged to be unintentional. There was a high rate of non‐attendance for follow‐up – 24%. The families of children admitted with burns were more likely to have moved home than those of controls (P = 0.001). By age 6 significantly more cases were admitted to hospital with an unrelated condition (P = 0.018). There were no differences between the cases and controls in immunization status, development, school attendance and educational progress up to the age of 6 years (P > 0.05).

Conclusions  We found important findings in relation to unintentional injury prevention and also noted markers that may indicate inequalities in health service utilization between cases and controls. There were no major differences between developmental and educational outcomes in the two groups.
Experience of four UK comprehensive care centres using FEIBA® for surgeries in patients with inhibitors
Authors: RANGARAJAN S. , YEE T. T. , WILDE J.
Published: July 2010

Summary.  Increasing evidence indicates that factor VIII (FVIII) inhibitor bypassing agents (FEIBA® and NovoSeven®) can provide effective peri‐operative haemostasis in haemophilia patients with high‐responding inhibitors. We report the collected experience of all major and minor surgeries, conducted between December 1998 and September 2008, at four UK haemophilia Comprehensive Care Centres with FEIBA® as the first‐line bypassing agent in patients with inhibitors. A total of 26 surgical procedures were performed in 18 patients of ages 34–83 years including five patients with acquired FVIII inhibitors. A single pre‐operative infusion of FEIBA was followed by 6–12 h interval dosing for major surgeries at the discretion of the physician to approximate a maximum of 200 U kg−1 day−1, with tapering when postoperative haemostasis and wound healing permitted. Haemostatic outcomes were retrospectively reviewed against European consensus thresholds for blood loss and duration of treatment compared with expectations for equivalent procedures in non‐inhibitor patients. Peri‐operative haemostatic outcome with FEIBA was rated excellent or good in 78% of 18 major surgeries in 12 patients, including 11 major orthopaedic procedures. Haemostatic outcome was rated excellent in all seven procedures in five patients with acquired FVIII inhibitors and in all eight minor surgical procedures in six patients. FEIBA was well tolerated with no intra‐operative haemostatic complications. A single, transient postoperative thrombotic adverse event occurred in a patient with cerebrovascular disease. This case series adds significantly to existing evidence that FEIBA can provide adequate, well‐tolerated, peri‐operative haemostatic cover for a wide variety of major and minor surgical procedures.
Relationship between clinical characteristics of narcolepsy and CSF orexin‐A levels
Authors: NAKAMURA MASAKI , KANBAYASHI TAKASHI , SUGIURA TATSUKI , INOUE YUICHI
Published: July 2010

Although an abnormally low cerebrospinal fluid (CSF)‐orexin level is well known to be a specific finding in narcoleptic patients, the relationships between the severity of the core symptoms of narcolepsy [i.e. daytime sleepiness and increased rapid eye movement (REM) propensity], as well as levels of obesity, and CSF‐orexin levels have not been well elucidated. The aim of this study was to examine the relationship between these characteristic symptoms of narcolepsy and CSF‐orexin level. Fifty‐three patients with narcolepsy with cataplexy (NA/CA) and 17 without cataplexy (NA w/o CA) were enrolled. Sleep latency and sleep onset REM latency were measured using the multiple sleep latency test (MSLT). Multiple linear regression analysis was used to determine factors associated with both mean sleep latency and mean sleep onset REM latency on MSLT, with %body mass index (BMI), gender, onset age, length of excessive daytime sleepiness (EDS) morbidity, diagnostic subgroup and CSF‐orexin levels being used as independent variables. The NA/CA group included a significantly higher number of patients with undetectable CSF‐orexin levels and shorter sleep onset and rapid eye movement (SOREM) latency, as well as a higher %BMI, versus NA w/o CA. Multiple linear regression analysis revealed that sleep latency was associated significantly with CSF‐orexin levels and gender. With regard to sleep onset REM latency and %BMI, only CSF‐orexin levels appeared to be a significantly associated factor. In narcoleptic patients, the severity of both excessive daytime sleepiness and increased REM propensity, as well as the level of obesity, could be associated with CSF‐orexin deficiency, rather than with subcategories of the disorder.
Phytoplasma PMU1 exists as linear chromosomal and circular extrachromosomal elements and has enhanced expression in insect vectors compared with plant hosts
Authors: Toruño Tania Y. , Seruga Musić Martina , Simi Silvia , Nicolaisen Mogens , Hogenhout Saskia A.
Published: July 2010

Phytoplasmas replicate intracellularly in plants and insects and are dependent on both hosts for dissemination in nature. Phytoplasmas have small genomes lacking genes for major metabolic pathways. Nevertheless, their genomes harbour multicopy gene clusters that were named potential mobile units (PMUs). PMU1 is the largest most complete repeat among the PMUs in the genome of Aster Yellows phytoplasma strain Witches' Broom (AY‐WB). PMU1 is c. 20 kb in size and contains 21 genes encoding DNA replication and predicted membrane‐targeted proteins. Here we show that AY‐WB has a chromosomal linear PMU1 (L‐PMU1) and an extrachromosomal circular PMU1 (C‐PMU1). The C‐PMU1 copy number was consistently higher by in average approximately fivefold in insects compared with plants and PMU1 gene expression levels were also considerably higher in insects indicating that C‐PMU1 synthesis and expression are regulated. We found that the majority of AY‐WB virulence genes lie on chromosomal PMU regions that have similar gene content and organization as PMU1 providing evidence that PMUs contribute to phytoplasma host adaptation and have integrated into the AY‐WB chromosome.
Generation of the heterodimeric precursor GP3 of the Chlamydomonas cell wall
Authors: Voigt Jürgen , Kieß Michael , Getzlaff Rita , Wöstemeyer Johannes , Frank Ronald
Published: July 2010

The cell wall of the unicellular green alga Chlamydomonas reinhardtii exclusively consists of hydroxyproline‐containing glycoproteins. Protein chemical analysis of its polypeptide constituents was hindered by their cross‐linking via peroxidase‐catalysed intermolecular isodityrosine formation and transaminase‐dependent processes. To overcome this problem, we have identified putative soluble precursors using polyclonal antibodies raised against deglycosylation products of the highly purified insoluble wall fraction and analysed their amino acid sequence. The occurrence of the corresponding polypeptide in the insoluble glycoprotein framework was finally probed by epitope mapping of the polyclonal antibodies using overlapping scan peptides which, together, cover the whole amino acid sequence of the putative precursor. As a control, peptide fragments released from the insoluble wall fraction by trypsin treatment were analysed by mass spectroscopy. By this approach, the heterodimeric, chaotrope‐soluble glycoprotein GP3 proved to be a constituent of the insoluble extracellular matrix of Chlamydomonas reinhardtii. Furthermore, we have shown that the polypeptide backbones of both GP3 subunits are encoded by the same gene and differ by a C‐terminal truncation in the case of GP3A.
Cellular metachromasia in Pompe's disease and Pelizaeus‐Merzbacher disease
Authors: Gertner Melvin , Zalay Erica , Hirschhorn Kurt
Published: July 2010

Two additional diseases, Pompe's disease and Pelizaeus‐Merzbacher disease, have been shown to demonstrate cellular metachromasia. In addition, our studies of metachromasia in fibroblasts from skin biopsies taken from patients with a variety of other disorders are described and our impression of the limited usefulness of metachromasia is discussed.
A familial Y/autosome translocation in man
Authors: Noel B. , Emerit Ingrid , Luciani J. M. , Quack Bernadette
Published: July 2010

For the first time, a translocation of a Y on a D chromosome has been shown in the males and females of the same family. The atypical aspect of a Dp+ made us aware of the possibility of a translocation of a Y on a D. This has been confirmed by autoradiographic study and fluorescent staining. The meiosis was arrested. The phenotypic effect is minimal.
Hypoplastic left heart syndrome: An autosomal recessive disorder
Authors: Shokeir M. H. K.
Published: July 2010

Five independent families with a total of thirteen patients with hypoplastic left heart syndrome are presented. In all affected infants, the course of the disease was inexorably progressive and ultimately fatal. The pattern of transmission in the reported families is consistent with autosomal recessive inheritance. Consanguinity could be clearly demonstrated among the parents in three of the reported sibships.
Studies of human chromosomes by DNA‐binding fluorochromes
Authors: Hagen Carl Birger van der , Berg Kåre
Published: July 2010

Previous work suggested that chromosomes 21 and 22 could be distinguished by fluorescent labelling of the chromosomes with quinacrine mustard (QM). This suggestion was confirmed in the present study of patients with Down's syndrome since it was found that in most cases three of the five G chromosomes had a clearly different distribution pattern from the remaining two. The pattern typical of chromosome 21 displays a particularly bright fluorescence in the middle of the long arm, whereas the fluorescence of chromosome 22 is less intense and more equally distributed along the length of the chromosome. Individual patterns of fluorescence have been observed in chromosome 21. Some of the implications of the findings are discussed.
More about X‐linked testicular feminization of the mouse as a noninducible (is) mutation of a regulatory locus: 5α‐androstan‐3α‐17ß‐diol as the true inducer of kidney alcohol dehydrogenase and ß‐glucuronidase
Authors: Ohno Susumu , Dofuku Ryuichi , Tettenborn Ulrich
Published: July 2010

A comparison of various androgenic steroids on +/Y ♂ and +/+♀ mice suggested that 5α‐an‐drostan‐3α‐17β‐diol, an intracellular metabolite of 5α‐dihydrotestosterone, is the true inducer of kidney alcohol dehydrogenase and β‐glucuronidase. The presence of a specific receptor protein (permease) for this inducer is doubtful. Instead, proximal tubule cells of the kidney appear to take in precursors of an inducer by pinocytosis. Only those cells which exhibit pinocytosis activity are inducible cells. It is suggested that an inducer reaches the cells of the embryonic Wolffian (mesonephric) duct in the same manner.

No induction of kidney ADH and β‐glucuronidase occurred in Tfm/Y mice following the administration of 5α‐androstan‐3α‐17β‐diol.
Incidence of cleft lip and palate in the offspring of cleft parents
Authors: Bixler David , Fogh‐Andersen P. , Conneally P. Michael
Published: July 2010

The results of this study support the idea that CL(P) is a polygenic trait. Furthermore, employing the calculations of Edwards, there was little evidence for major gene effects. The sex‐modified threshold concept which has been made an integral part of the CL(P) polygenic model was not entirely confirmed by these data.

These data show an affected offspring risk for CP parents of both sexes of about 6 %. Although Edward's calculations failed to provide evidence for major gene effects in CP, there was an unexplained five‐fold difference between CP frequency in offspring and sibs which needs further study.
Evaluation of dermal patterns in Down's syndrome by predictive discrimination
Authors: Bolling David R. , Borgaonkar Digamber S. , Herr Helen M. , Davis Miles
Published: July 2010

Independence of left and right dermal pattern areas were examined in Down's syndrome patients and controls. A composite score was then developed as a laboratory test to confirm the clinical diagnosis of Down's syndrome. The score demonstrates better discrimination by correctly scoring 97.7% of the individuals tested whereas the single pattern scoring method correctly scored 96.6%. An element of simplicity is also gained by using composite scores. It corrects in part the error due to correlation of the occurrence of patterns on the two sides.
Familial de Lange syndrome
Authors: Beratis Nicholas G. , Hsu Lillian Y. F. , Hirschhorn Kurt
Published: July 2010

Familial de Lange syndrome with 3 affected siblings in a sibship of 4 is described. The parents were phenotypically normal. No parental consanguinity was demonstrated. The karyotypes of the affected siblings were normal. Although the etiology of the syndrome is obscure, it is likely that it consists of a heterogeneous group of clinical entities. Morphologic criteria may be useful in distinguishing the sporadic cases from the familial ones.
6‐Phosphogluconate dehydrogenase (6‐P‐GD) in Down's syndrome
Authors: Lisker RUBÉN , Mora Guillermina , Buentello Leonora , Armendares Salvador
Published: July 2010

The question of whether the 6‐P‐GD system is located in chromosome 21 was approached in 2 ways: by measuring the erythrocyte 6‐P‐GD levels in children with Down's syndrome, and by studying the segregation of the electrophoretic variants of this enzyme in families with Down's syndrome individuals. Accepting that maternal meiotic non‐disjunction is the most frequent cause of the disease, there should be an excess of AB‐affected individuals born to AB mothers. The results do not support earlier suggestions that the 6‐P‐GD locus is located in chromosome 21.
Lysinuric protein intolerance, an autosomal recessive disease
Authors: Norio R. , Perheentupa J. , Kekomäki M. , Visakorpi J. K.
Published: July 2010

Lysinuric protein intolerance (LPI) is characterized by failure to thrive, diarrhea and vomiting associated with protein intake, aversion to protein‐rich food, growth retardation, hepatomegaly, hyperammonemia, and deficient urea formation after an amino nitrogen load, and increased urinary excretion of basic amino acids, especially lysine. LPI has been diagnosed in 16 patients of 10 families in Finland and in one Finnish immigrant in Sweden. In this study data were evaluated to test the autosomal recessive transmission of LPI.

In 6 families out of 10 the occurrence was familial. The sex ratio of those affected was 6 : 10. The proportion of affected sibs, corrected by Apert's a priori method, was 0.26. In 5 families the parental marriage was consanguineous, and in two groups of two families all four parents were descendants of one ancestor pair. The geographical distribution of the LPI ancestors was uneven as is true for many rare recessive diseases in Finland. No heterozygous effects of the LPI gene could be detected with certainty. These finclings constitute evidence in favor of the autosomal recessive transmission of LPI.
Syndrome characterized by lingual malformation, Polydactyly, tachypnea, and psychomotor retardation (Mohr syndrome)
Authors: Gustavson K. ‐H. , Kreuger A. , Petersson P. O.
Published: July 2010

A 2‐year‐old girl, who at birth exhibited lingual malformation, Polydactyly, and tachypnea and who subsequently developed severe psychomotor retardation, is described. The syndrome corresponds to the Mohr syndrome and is compared with the oral‐facial‐digital (OFD) syndrome from a clinical and genetic point of view.
A genetic and statistical study of some sex‐related factors in Huntington's disease
Authors: Brackenridge C.L.
Published: July 2010

From an analysis of published sibships containing at least one subject with Huntington's disease, evidence was obtained from segregation ratios derived from several hypothetical modes of ascertainment that single‐membered sibships are less likely to be recorded than those containing at least two affectcd persons and that the probability of reporting a sibship is proportional to the number of affected siblings.

Familial sex‐limitation and partial sex‐linkage could not be detected in the sample. Investigation of parental and grandparcntal lines ol transmission revealed that patrilineal descent predominated for all subjccts except unaffected daughters. Mcan ages at onset and death wcrc independent of the 5ex of the subject or the tranymitting parent. On the other hand, the offspring of affected males suffered from the disorder for a shorter period of time than offspring of affccted females. Ages at onsct and death varied significantly from generation to generation, presumably because parents are ofren ascertained through their children in the literature and the phenomenon of anticipation thereby arises. Onset age was earlier in members of small sihships than in those of large sibships. This could be related to the earlier onset age of parents producing small families compared with those producing large families.
Dyschondrosteosis. A Mexican family with two affected males
Authors: Lisker R. , Gamboa I. , Hernández J.
Published: July 2010

This paper is the first report of a Mexican family with dyschondrosteosis. The index case was a female, but two mildly affected males were identified. Without X‐ray examination it is impossible to exclude the presence of the disease. This has not been made routinely in previously reported families, and therefore the great excess of affected females found in the literature could be explained partially by this fact. Furthermore females might seek consultation for cosmetic reasons more often than males. Nine autosomal markers were investigated in the available family members, the results being informative only in the Rhesus and haptoglobin systems. No indication of close linkage to the dyschondrosteosis locus was found.
A quantitative method for determining γG allotype antigens
Authors: Litwin S. D.
Published: July 2010

The sera expression of human immunoglobulin heavy chain genes and gene complexes was analyzed in different ethnic groups by quantitative determination of Gm allotype antigens. In all populations tested, IgG3 subclass heavy chains of Gm(b+) allotype had greater sera expression than the allele Gm(g). The percentage of IgG3 allotype molecules was higher in Chinese and Easter Islanders than in Caucasians due to higher Gm(b) values. In general, IgG1 allotypes did not show quantitative differences correlated with Gm genotype. A possible exception was the Gmza, g gene complex which had a lower Gm(a) concentration than comparable Chinese sera of different genotype. Certain similarities in the regulation of Gm genes were consistently observed among the populations tested; these included the restricted range of percentage of IgG1 allotype antigens, a gene dosage effect, and differential gene activity of Gmb and Gmg IgG3 Gm genes.
Thyroid antibodies: A study of first degree relatives
Authors: Hall R. , Dingle P. R. , Roberts D. F.
Published: July 2010

A study has been made of the presence of thyroid antibodies in the relatives of a random sample of elderly subjects, not selected on the basis of a thyroid disorder. The presence of antibodies was tested by the tanned red cell technique. The results suggest that the ability to form antibodies is under polygenic control and is of moderate heritability (upper limit approximately 53 %).
Cytogenetic findings in a parent of a patient with Fanconi's anemia
Authors: Lieber Ernest , Hsu Lillian , Spitler Lynn , Fudenberg H. H.
Published: July 2010

We have studied a patient with clinically established Fanconi type anemia whose peripheral blood leukocyte culture and bone marrow showed a normal male karyotype, with no morphological alterations. The skin fibroblasts in cultures derived from his father, however, revealed a mosaic pattern,47, XY F+/46, XY. The findings of a trisomic cell line in a parent of a patient with Fanconi's anemia has been reported only once before.
The relation of some features of Huntington's disease to the age at onset of symptoms in parents
Authors: Brackenridge C. I.
Published: July 2010

To determine whether the parental age at onset of Huntington's disease plays a significant role in defining the clinical picture in affected offspring, a statistical study was made of cases drawn from the literature. The relation of parental onset age to the predominant neurological sign (chorea or rigidity), order of appearance of neurological and psychiatric symptoms, sex and onset age of offspring was calculated by analysis of variance and partial correlation. Sex of parent and of offspring were not important, but the remaining factors exerted significant effects. It was concluded that parental onset age is a significant factor in the order of appearance and age at onset of symptoms in offspring, but that neurological sign is intrinsically related to the onset age of the subject.
Zymograms of the human red cell acid phosphatase obtained with different substrates
Authors: SØRENSEN S. A.
Published: July 2010

A lead‐sulfide method has been developed to produce zymograms of human red cell acid phosphatase. Two somewhat different zymograms were detected; the one was obtained with phenyl phosphate or [3‐naphthyl phosphate and the other with p‐nitrophenyl phosphate or phenolphthalein diphosphate as the substrate. On this basis it was suggested that these substrates could be classified into two groups: aromatic compounds with no substituent in addition to the ester group; and compounds with a substituent attached to the carbon at the para position relative to the ester group. The idea that the position of a substituent may be of importance for the catalytic activity of the red cell acid phosphatase was supported by the observation that o‐ and m‐nitrophenyl phosphate were only slowly hydrolyzed in contrast to p‐nitrophenyl phosphate.
The ectrodactyly‐ectodermal dysplasia‐clefting (EEC) syndrome
Authors: Bixler D. , Spivack J. , Bennett J. , Christian J. C.
Published: July 2010

A search of the literature over the past 150 years reveals 19 proband cases of lobster claw deformity of the extremities and clefting of the primary and secondary palate. Some authors have reported that a few of these cases also have an atypical form of ectodermal dysplasia in which the skin is fair and the hair fine and light colored, and a tooth enamel dysplasia but normal salivary, sweat, and sebaceous gland function. Atresia of the lacrimal puncta may also be a part of this syndrome which has been designated the ectrodactyly‐ectodermal dysplasia‐clefting (EEC) syndrome. This report describes two unrelated females who appear to have the EEC syndrome, thereby bringing the total probable cases to five, two of which occurred in affected families (Walker & Clodius 1963, Cockayne 1936) and three of which were sporadic (Rudiger et al. 1970, this report). Dominant inheritance with incomplete penetrance is suggested.
Problems in prenatal diagnosis resulting from chromosomal mosaicism
Authors: Kardon N. B. , Chernay P. R. , Hsu L. Y. F. , Martin J. L. , Hirschhorn K.
Published: July 2010

Prenatal diagnosis was performed on a 36‐year‐old woman with a history of Tay‐Sachs disease in one of her children. A diagnosis of 45, X was made by conventional karyotype analysis on the first amniotic fluid specimen. Cells from this specimen also showed a small fluorescent body, leading to suspicion of the presence of a Y chromosome. Special staining techniques demonstrated a possible D/Y translocation. The patient elected to have a therapeutic abortion and a male fetus was expelled. Subsequent culture of the amniotic fluid obtained at the time of abortion revealed 46,XY. The indications for prenatal cytogenetic diagnosis, the problems of diagnosing in utero mosaicism, and the problems resulting from the application of new methods of chromosome identification are discussed.
The Meckel syndrome with limited expression in relatives
Authors: Fitch Naomi , Pinsky Leonard
Published: July 2010

An infant with a pattern of malformations suggestive of the Meckel syndrome was born to consanguineous parents. Several of his relatives had congenital anomalies interpretable as incomplete expressions of the syndrome. Up to now the literature has paid little attention to this aspect of the Meckel syndrome.
The influence of obstetric complications on the clinical picture in classical phenylketonuria
Authors: Saugstad L. Fegersten
Published: July 2010

Obstetric complication was defined as three or more non‐optimal obstetric conditions as described by Prechtl. Only 22 of the 74 untreated cases with phenylketonuria (PKU) who were investigated had been delivered without obstetric complications. While more than 50 % of those PKUs achieved an IQ within the debile range, only about 20 % reached this level of intelligence when birth was associated with complication. The incidence of salaam seizures, pathological EEGs, neurological deficits, excessive vomiting and delayed development from birth also increased with increasing evidence of obstetric complications. It is concluded that obstetric complications are mainly responsible for the great variation in the clinical picture of PKU. The insufficiency of dietary treatment in achieving similar intellectual development in PKUs as in their non‐PKU sibs is probably related to this increased perinatal susceptibility of PKUs, which in turn is related to their prenatally reduced rate of growth. Even if the optimal result of dietary treatment is obtained there may be learning problems of an organic character. Taken as a whole, the prognosis concerning mental achievement was considerably better than has generally been assumed, for there were as many with IQs within the debile as within the low grade defective range. Male PKUs had a markedly reduced chance of attaining an IQ within the debile range, and this is probably due to the higher male perinatal morbidity.
Pre‐symptomatic detection and genetic counselling in myotonic dystrophy
Authors: Harper Peter S.
Published: July 2010

A study of patients with myotonic dystrophy and their first degree relatives has shown that 17.6 % of asymptomatic individuals at risk were definitely affected on the basis of neurological and slit lamp examination, while a further 13.7 % showed suspicious but not diagnostic changes. In those individuals who were definitely affected neurologically, a high incidence of lens opacities was shown by the slit lamp, except during the first decade of life. Analysis of penetrance of the myotonic dystrophy gene in the offspring of affected individuals suggested that penetrance was largely complete by adulthood. No instance of mutation was encountered in the study, and it is suggested that undetected transmission is much more frequently responsible for the apparently isolated case than is mutation. The use in genetic counselling and prenatal diagnosis of the various methods of detecting the myotonic dystrophy gene is discussed.