Synthetic MR Imaging-Based WM Signal Suppression Identifies Neonatal Brainstem Pathways in Vivo

BACKGROUND AND PURPOSE

Multidynamic multiecho sequence-based imaging enables investigators to reconstruct multiple MR imaging contrasts on the basis of a single scan. This study investigated the feasibility of synthetic MRI-based WM signal suppression (syWMSS), a synthetic inversion recovery approach in which a short TI suppresses myelin-related signals, for the identification of early myelinating brainstem pathways.

MATERIALS AND METHODS

Thirty-one cases of neonatal MR imaging, which included multidynamic multiecho data and conventionally acquired T1- and T2-weighted sequences, were analyzed. The multidynamic multiecho postprocessing software SyMRI was used to generate syWMSS data (TR/TE/TI = 3000/5/410 ms). Two raters discriminated early myelinating brainstem pathways (decussation of the superior cerebellar peduncle, medial lemniscus, central tegmental tract, and medial longitudinal fascicle [the latter 3 assessed at the level of the pons]) on syWMSS data and reference standard contrasts.

RESULTS

On the basis of syWMSS data, the decussation of the superior cerebellar peduncle (31/31); left/right medial lemniscus (31/31; 30/31); left/right central tegmental tract (19/31; 20/31); and left/right medial longitudinal fascicle (30/31) were reliably identified by both raters. On the basis of T1-weighted contrasts, the decussation of the superior cerebellar peduncle (14/31); left/right medial lemniscus (22/31; 16/31); left/right central tegmental tract (1/31); and left/right medial longitudinal fascicle (9/31; 8/31) were reliably identified by both raters. On the basis of T2-weighted contrasts, the decussation of the superior cerebellar peduncle (28/31); left/right medial lemniscus (16/31; 12/31); left/right central tegmental tract (23/31; 18/31); and left/right medial longitudinal fascicle (15/31; 14/31) were reliably identified by both raters.

CONCLUSIONS

syWMSS data provide a feasible imaging technique with which to study early myelinating brainstem pathways. MR imaging approaches that use myelin signal suppression contribute to a more sensitive assessment of myelination patterns at early stages of cerebral development.

Different from the Beginning: WM Maturity of Female and Male Extremely Preterm Neonates-A Quantitative MRI Study

BACKGROUND AND PURPOSE

Former preterm born males are at higher risk for neurodevelopmental disabilities compared with female infants born at the same gestational age. This retrospective study investigated sex-related differences in the maturity of early myelinating brain regions in infants born <28 weeks' gestational age using diffusion tensor- and relaxometry-based MR imaging.

MATERIALS AND METHODS

Quantitative MR imaging sequence acquisitions were analyzed in a sample of 35 extremely preterm neonates imaged at term-equivalent ages. Quantitative MR imaging metrics (fractional anisotropy; ADC [10^-3mm²/s]; and T1-/T2-relaxation times [ms]) of the medulla oblongata, pontine tegmentum, midbrain, and the right/left posterior limbs of the internal capsule were determined on diffusion tensor- and multidynamic, multiecho sequence-based imaging data. ANCOVA and a paired t test were used to compare female and male infants and to detect hemispheric developmental asymmetries.

RESULTS

Seventeen female (mean gestational age at birth: 26 + 0 [SD, 1 + 4] weeks+days) and 18 male (mean gestational age at birth: 26 + 1 [SD, 1 + 3] weeks+days) infants were enrolled in this study. Significant differences were observed in the T2-relaxation time (P = .014) of the pontine tegmentum, T1-relaxation time (P = .011)/T2-relaxation time (P = .024) of the midbrain, and T1-relaxation time (P = .032) of the left posterior limb of the internal capsule. In both sexes, fractional anisotropy (P [♀] < .001/P [♂] < .001) and ADC (P [♀] = .017/P [♂] = .028) differed significantly between the right and left posterior limbs of the internal capsule.

CONCLUSIONS

The combined use of various quantitative MR imaging metrics detects sex-related and interhemispheric differences of WM maturity. The brainstem and the left posterior limb of the internal capsule of male preterm neonates are more immature compared with those of female infants at term-equivalent ages. Sex differences in WM maturation need further attention for the personalization of neonatal brain imaging.

Mapping Human Fetal Brain Maturation In Vivo Using Quantitative MRI

BACKGROUND AND PURPOSE

On the basis of a single multidynamic multiecho sequence acquisition, SyMRI generates a variety of quantitative image data that can characterize tissue-specific properties. The aim of this retrospective study was to evaluate the feasibility of SyMRI for the qualitative and quantitative assessment of fetal brain maturation.

MATERIALS AND METHODS

In 52 fetuses, multidynamic multiecho sequence acquisitions were available. SyMRI was used to perform multidynamic multiecho-based postprocessing. Fetal brain maturity was scored qualitatively on the basis of SyMRI-generated MR imaging data. The results were compared with conventionally acquired T1-weighted/T2-weighted contrasts as a standard of reference. Myelin-related changes in T1-/T2-relaxation time/relaxation rate, proton density, and MR imaging signal intensity of the developing fetal brain stem were measured. A Pearson correlation analysis was used to detect correlations between the following: 1) the gestational age at MR imaging and the fetal brain maturity score, and 2) the gestational age at MR imaging and the quantitative measurements.

RESULTS

SyMRI provided images of sufficient quality in 12/52 (23.08%) (range, 23 + 6-34 + 0) fetal multidynamic multiecho sequence acquisitions. The fetal brain maturity score positively correlated with gestational age at MR imaging (SyMRI: r = 0.915, P < .001/standard of reference: r = 0.966, P < .001). Myelination-related changes in the T2 relaxation time/T2 relaxation rate of the medulla oblongata significantly correlated with gestational age at MR imaging (T2-relaxation time: r = -0.739, P = .006/T2-relaxation rate: r = 0.790, P = .002).

CONCLUSIONS

Fetal motion limits the applicability of multidynamic multiecho-based postprocessing. However, SyMRI-generated image data of sufficient quality enable the qualitative assessment of maturity-related changes of the fetal brain. In addition, quantitative T2 relaxation time/T2 relaxation rate mapping characterizes myelin-related changes of the brain stem prenatally. This approach, if successful, opens novel possibilities for the evaluation of structural and biochemical aspects of fetal brain maturation.

Impact of Prematurity on the Tissue Properties of the Neonatal Brain Stem: A Quantitative MR Approach

BACKGROUND AND PURPOSE

Preterm birth interferes with regular brain development. The aim of this study was to investigate the impact of prematurity on the physical tissue properties of the neonatal brain stem using a quantitative MR imaging approach.

MATERIALS AND METHODS

A total of 55 neonates (extremely preterm [n = 30]: <28 + 0 weeks gestational age; preterm [n = 10]: 28 + 0-36 + 6 weeks gestational age; term [n = 15]: ≥37 + 0 weeks gestational age) were included in this retrospective study. In most cases, imaging was performed at approximately term-equivalent age using a standard MR protocol. MR data postprocessing software SyMRI was used to perform multidynamic multiecho sequence (acquisition time: 5 minutes, 24 seconds)-based MR postprocessing to determine T1 relaxation time, T2 relaxation time, and proton density. Mixed-model ANCOVA (covariate: gestational age at MR imaging) and the post hoc Bonferroni test were used to compare the groups.

RESULTS

There were significant differences between premature and term infants for T1 relaxation time (midbrain: P < .001; pons: P < .001; basis pontis: P = .005; tegmentum pontis: P < .001; medulla oblongata: P < .001), T2 relaxation time (midbrain: P < .001; tegmentum pontis: P < .001), and proton density (tegmentum pontis: P = .004). The post hoc Bonferroni test revealed that T1 relaxation time/T2 relaxation time in the midbrain differed significantly between extremely preterm and preterm (T1 relaxation time: P < .001/T2 relaxation time: P = .02), extremely preterm and term (T1 relaxation time/T2 relaxation time: P < .001), and preterm and term infants (T1 relaxation time: P < .001/T2 relaxation time: P = .006).

CONCLUSIONS

Quantitative MR parameters allow preterm and term neonates to be differentiated. T1 and T2 relaxation time metrics of the midbrain allow differentiation between the different stages of prematurity. SyMRI allows for a quantitative assessment of incomplete brain maturation by providing tissue-specific properties while not exceeding a clinically acceptable imaging time.

Spectrum of mutations in the familial Mediterranean fever gene (MEFV) in Turkish patients of the Central Anatolia region: a comparison of two mutation detection system

The purpose of this study was to determine the spectrum of the most common mutations in the familial Mediterranean fever gene (MEFV) in Turkish patients from the Central Anatolia region, by using two different methods for detecting FMF-associated mutations with different screening panels, and compare our results with other diagnostic molecular genetics centers. A total of 1579 patients were analyzed. Genomic DNA from 304 patients was tested for 6 common mutations located in exon 2 (E148Q), and exon 10 (M680I, M694V, M694I, V726A, R761H) by real-time PCR while 1275 patients were tested for 17 mutations located in exon 2 (E148Q), and exon10 [M680I (G/C), M680I (G/A), I692del, M694V, M694I, K695R, V726A, S675N, G678E, M680L, T681I, M694L, K695M, R717S, I720M, V722M] by pyrosequencing. The most frequent mutation was M694V, followed by M680I, E148Q, and V726A. Ten mutations in the panel were not detected in any patients. Finally, we compared our results with those of other centers in Turkey to contribute to the identified spectrum of Turkish MEFV mutations and we discuss which MEFV mutations are informative for evaluating an FMF patient.

Warburg micro syndrome in two children from a highly inbred Turkish family

Warburg Micro syndrome (WMS) was first reported by Warburg in 1993. The cardinal features are microcephaly, microphthalmia, congenital cataract and intellectual disability. We report on two children from a highly inbred family with microcephaly, congenital cataract, optic atrophy, hypotonia and severe psychomotor retardation. This phenotype is similar to other reported rare entities and especially to the family reported by Warburg. Four other children in the same family may also have been affected. In this report, the symptoms and features of our cases are compared with the Warburg Micro syndrome patients in literature.

Effect of mobile phone station on micronucleus frequency and chromosomal aberrations in human blood cells

The use of mobile telephones has rapidly increased worldwide as well as the number of mobile phone base stations that lead to rise low level radiofrequency emissions which may in turn have possible harm for human health. The national radiation protection board has published the known effects of radio waves exposure on humans living close to mobile phone base stations. However, several studies have claimed that the base station has detrimental effects on different tissues. In this study, we aimed to evaluate the effects of mobile phone base stations on the micronucleus (MN) frequency and chromosomal aberrations on blood in people who were living around mobile phone base stations and healthy controls. Frequency of MN and chromosomal aberrations in study and control groups was 8.96 +/- 3.51 and 6.97 +/- 1.52 (p: 0.16); 0.36 +/- 0.31 and 0.75 +/- 0.61 (p: 0.07), respectively. Our results show that there was not a significant difference of MN frequency and chromosomal aberrations between the two study groups. The results claim that cellular phones and their base stations do not produce important carcinogenic changes.

Hopelessness of mothers who have children with Down syndrome

This study was conducted to determine hopelessness status of mothers who have children with Down syndrome. Beck Hopelessness Scale was used in this restrictive type study. The average value of mothers enrolled in the study was detected as 8.29 +/- 2.49. Age, education level, socio-economical status, work and the problems between parents were also examined and it was found that there is a relationship between the education level, socio-economical status, the problems between parents and the hopelessness scale (p < 0.01). Consequently, it is apparent that the mothers who have children with Down syndrome need social and psychological support to overcome their feelings of hopelessness.

Unreported "de novo" rearrangement of chromosomes 4 and 7

Unreported "de novo" rearrangement of chromosomes 4 and 7: Unbalanced rearrangements of the chromosomes are extremely rare and associated with an abnormal phenotype and usually result in an abortion in early pregnancy. The current literature includes reports on the conditions related with rearrangements of chromosome 4 and 7. Herein, we describe a rearrangement between these two chromosomes, which is the first presentation ofa specific translocation t(4;7)(q31;p15) and its consequent phenotype following de novo rearrangement of the chromosomes. It brought into light phenotypic similarities with other aberrations following breakage from adjacent band loci. We hope these features will help further genetic investigations on these chromosome regions.

Down syndrome associated with severe combined immunodeficiency: a case report

An 8-month-old boy was admitted to the hospital because of recurrent bronchopneumonia and gastrointestinal tract infections. On physical examination, he had hypotonia, mental retardation, microcephaly with flat facies, low nasal bridge, small nose, small ears. Laboratory evaluation revealed Down syndrome, lymphopenia, hypogammaglobulinemia, reduced proportions of the peripheral blood lymphocytes with an inverted CD4/CD8 ratio and markedly reduced mitogen response of the lymphocytes. We report here unique case of Down syndrome associated with severe combined immunodeficiency.

Adsorption of human salivary mucin MG1 onto glow-discharge plasma treated acrylic resin surfaces

It has been suggested that altering the surface properties of acrylic resin material may change the nature of the adsorbed pellicle affecting denture retention and microbial adherence. This study aimed at evaluating the adsorption of salivary high molecular-weight mucins, a major component of denture pellicle, onto modified acrylic resin surfaces. (Poly) methylmethacrylate specimens were treated by glow discharge plasma technique, using hydrophilic 2-Hydroxyethylmethacrylate monomer or oxygen (O(2)) gas and hydrophobic Hexamethyldisiloxane monomer, at different discharge powers. Acrylic samples were incubated with high-molecular weight mucin, MG1 purified from saliva, the adsorbed fractions were transferred to nitrocellulose membranes by slot-blot technique, stained by periodic acid-Schiff and colour intensities were analysed by a colour densitometer. Higher amounts of mucins were adsorbed on all the surfaces modified by glow-discharge plasma treatment. Within the limitations of this study, it was concluded that glow-discharge plasma altered the surfaces of acrylic resin denture base materials and significantly increased the adsorption of high molecular-weight mucins at varying levels depending on plasma parameters.

Ectrodactyly, ectodermal dysplasia, macular degeneration syndrome: a further contribution

EEM syndrome is a rare condition characterised by ectodermal dysplasia, ectrodactyly and macular dystrophy. Additional abnormalities such as alopecia, cataract, absent eyebrows, and oligodontia may occur. We report two brothers and a sister born to consanguineous parents with EEM syndrome. EEM syndrome differs from other ectrodactly syndromes by the characteristic findings in the ocular fundus showing extensive retinochoroidal atrophy with diffuse retinal pigmentation and mild arteriolar attenuation at the posterior pole. In contrast to other ectrodactyly syndromes autosomal recessive inheritance is most likely.

Adherence of Candida albicans to glow-discharge modified acrylic denture base polymers

An important aetiologic factor in the pathogenesis of denture-induced stomatitis, is the presence of numerous yeasts, usually Candida albicans, on the fitting surfaces of dentures. In the present study, effect of glow-discharge plasma, a technique applied to increase surface wettability of acrylic resins, on candidial adherence was evaluated. The durability of glow-discharge modification with saliva coating was also evaluated. Samples including control and experimental groups were prepared by using heat compression mould technique. To create a hydrophobicity gradient, experimental groups were exposed to a radiofrequency glow discharge in an O2 atmosphere under different discharge powers. To characterize the wetting properties, an expression of surface hydrophobicity, contact angle measurements were performed by the sessile drop method. The organism used was C. albicans (ATTC10321). Acrylic samples were coated with unstimulated whole saliva collected from a healthy man. The fungal suspension was poured on saliva-inoculated samples and incubated at 37 degrees for 2 h. The samples were then fixed with glutaraldehyde and Gram stained. Adhered candidial cells were examined by light microscope. Diffuse Reflectance FTIR (DRIFT) and scanning electron-microscope examinations were also performed to evaluate the surface composition and roughness of the test groups. Glow-discharge plasma was found to be an effective means of increasing surface wettability even with salivary pellicle. Amounts of candida cells adhered were significantly higher in all the plasma treated surfaces than the unmodified control group (P < 0.001). It was concluded that improving the surface wettability of acrylic resins by glow-discharge plasma in O2 atmosphere increased the adherence of the C. albicans.

Reliability and efficiency of interphase-fish with alpha-satellite probe for detection of aneuploidy

Early diagnosis is very important in pre- and postnatal diagnosis of Down syndrome. This study examines the use of fluorescence in situ hybridization (FISH) to detect trisomy 21 in interphase nuclei and metaphase chromosome obtained from fifty-four Down syndrome patients with a regular type trisomy 21. Three of them showed six hybridization signals on both interphase nuclei and metaphase spreads instead of five signals corresponding to two chromosomes 13 and three chromosomes 21 although they were cytogenetically trisomy 21. Simultaneous application of probe combination revealed that one of the extra signals of chromosomes 13/21 a-satellite probe was located on chromosome 22 in two cases and one extra signal on chromosomes 15 in one case. In addition, another case showed four hybridization signals on both interphase nuclei and metaphase spreads instead of five signals, indicating deletion of the chromosome specific alpha-satellite DNA sequence of chromosome 13/21. These centromeric sequence changes may have pathological significance in the appearance of aneuploidy because they may be involved in the important centromere function.

Hyperdiploid karyotype in a childhood MDS patient

We present a rare case of a paediatric myelodysplastic syndrome (MDS) with congenital anomalies (frontal bossing and premature closure of anterior fontanelle). The case showed the clinical and biological features of a refractory anaemia excess blasts (RAEB). Bone marrow (BM) cytogenetics demonstrated a hyperdiploid karyotype, with several numerical abnormalities and unidentified rearrangements. Fluorescence in situ hybridization (FISH) using chromosome specific alpha-satellite and whole chromosome-specific painting probes verified the hyperdiploid karyotype, and confirmed the origin of the unknown markers and rearrangements more reliably than would be possible using conventional cytogenetic techniques.