Block-like Pattern Research Articles

Low rates of neurological abnormalities in patients with pigmentary mosaicism: A retrospective cohort study from a tertiary dermatology center.

Pigmentary mosaicism (PM) is a descriptive term encompassing a range of hyper- and hypo-pigmented phenotypes in various patterns. Information from the neurology literature initially noted neurological abnormalities (NA) in up to 90% of children with PM. The dermatology literature suggests lower associated rates (15%-30%) of NA. Variations in terminology, inclusion criteria, and small population sizes makes interpreting existing PM literature complicated. We aimed to assess rates of NA in children presenting to dermatology with PM. We included patients <19 years, diagnosed with PM, nevus depigmentosus and/or segmental café au lait macules (CALM) seen in our dermatology department between 1 January 2006 and 31 December 2020. Patients with neurofibromatosis, McCune-Albright syndrome, and non-segmental CALM were excluded. Data collected included pigmentation, pattern, site(s) affected, presence of seizures, developmental delay, and microcephaly. One hundred fifty patients were included (49.3% female), with a mean age at diagnosis of 4.27 years. Patterns of mosaicism were ascertained for 149 patients and included blaschkolinear (60/149, 40.3%), blocklike (79/149, 53.0%), or a combination of both patterns (10/149, 6.7%). Patients with a combination of patterns were more likely to have NA (p <.01). Overall, 22/149 (14.8%) had NA. Nine out of twenty-two patients with NA had hypopigmented blaschkolinear lesions (40.9%). Patients with ≥4 body sites affected were more likely to have NA (p <.01). Overall, our population had low rates of NA in PM patients. A combination of blaschkolinear and blocklike patterns, or ≥4 body sites involved were associated with higher rates of NA.

Differences in Accessibility of Public Health Facilities in Hierarchical Municipalities and the Spatial Pattern Characteristics of Their Services in Doumen District, China

This study used the two-step floating catchment area method and potential model to calculate facility accessibility and potential service scope of public health infrastructure distribution, and to evaluate its spatial equity. We applied the Gini coefficient to measure the spatial equilibrium at each level of public health infrastructure in Doumen District, Guangdong, China, from different perspectives. The following results were obtained: (1) Significant spatial differences were observed in the accessibility of public health facilities among different levels; the higher the health facility level, the greater the difference in spatial accessibility. Spatial differences in the accessibility of public health infrastructure at the primary level and higher were distributed in a block-like pattern, while spatial differences in the accessibility of rural health stations were distributed in a circular pattern. Administrative villages tended to have the highest and lowest accessibility of tertiary and secondary hospitals, but not of primary hospitals and rural health stations. The frequencies for administrative villages with the highest and lowest accessibility were 32.8% and 49.6% of the total number of villages in the district, respectively, for tertiary hospitals; 39.2% and 48.8% for secondary hospitals; 19.2% and 24.8% for primary hospitals; 16.8% and 21.6% for rural health stations. (2) The potential service scope was spatially dissociative for tertiary hospitals, and differed more significantly in terms of space for secondary hospitals; the potential service scope of the two overlapped. The potential service scope of primary hospitals was relatively balanced, with strong spatial continuity, while that of rural health service centers was spatially fragmented. The service scope of rural health service centers was mostly consistent with their respective village-level administrative divisions. (3) The higher the level of public health infrastructure, the less balanced its spatial layout. Conversely, the lower the level of public health infrastructure, the more balanced its spatial layout.

Large-earthquake rupturing and slipping behavior along the range-front Maidan fault in the southern Tian Shan, northwestern China

Slipping behavior of active thrust faults are not well explored because of their variable vertical displacements governed by dip-angle changes along the fault striking. The range-front Maidan fault (MDF) is a thrust fault in the southern Tian Shan, and exhibits clear paleoearthquake rupturing during the late Quaternary. In this study, based on field investigation, trench exposing, detailed terrace surveying with differential GPS, and optically stimulated luminescence (OSL) dating, we revealed that the latest paleoearthquake on the MDF occurred at ~1.76 ka, and generated a vertical displacement of ~3.0 m. Then, we analyzed the vertical displacements on different terraces of the Yushanguxi River versus the corresponding terrace 10Be exposure ages. We suggest that the large-earthquake on the MDF is an irregular recurrence. The MDF still has a high seismic risk in spite of only ~1.76 ka elapsed time for the latest paleoearthquake. We propose that the growth and uplift of the western Tian Shan orogen is caused by fault thrusting and crustal shortening of a series of block-like patterns.

An S wave in ECG lead V6 predicts poor response to cardiac resynchronization therapy and long-term outcome

Cardiac resynchronization therapy (CRT) is a standard treatment for selected patients with chronic heart failure(HF). However, up to 30%-50% of patients still do not respond to CRT. Our aim was to identify the predictive value of an S wave in lead V6 in CRT response in patients with complete left bundle branch block (CLBBB). The CLBBB definition included the Strauss left bundle branch block criteria and the absence of q waves in leads I, V5, and V6. According to the electrocardiogram at baseline, CLBBB patients were divided into 3 groups: T-CLBBB group (CLBBB without an S wave in lead V5 or V6), V5S group (CLBBB with an S wave in lead V5 and no S wave in lead V6), and V5&V6S group (CLBBB with S waves in leads V5 and V6). CRT response was defined as left ventricular end-systolic volume reduction ≥ 15% at 6-month follow-up. The combined end point included HF rehospitalization or all-cause death. Of 181 patients with left bundle branch block-like pattern, 112 patients with CLBBB were included into 3 groups: 54 in the T-CLBBB group, 32 in the V5S group, and 26 in the V5&V6S group. The CRT response rate was 85.2% (46), 65.6% (21), and 38.5% (10), respectively (P < .001). Kaplan-Meier curves demonstrated that patients in the V5&V6S group had a higher incidence of HF rehospitalization or all-cause death than those in the other 2 groups (P < .001). In a multivariate logistic regression model analysis, an S wave in lead V6 was significantly associated with CRT nonresponse (hazard ratio 0.33; 95% confidence interval 0.11-0.96; P = .042). An S wave in lead V6 can predict poor response to CRT and long-term outcome.

Right Bundle Branch Block-Like Pattern During Uncomplicated Right Ventricular Pacing and the Effect of Pacing Site

Right bundle branch block (RBBB) configuration is an unexpected finding during right ventricular (RV) pacing that raises the suspicion of inadvertent left ventricular lead positioning. The aim of this study was to evaluate the prevalence of paced RBBB pattern in relation to RV lead location. This is a secondary analysis of a prospective, multicenter study, which randomized implantable cardioverter defibrillator recipients to an apical versus midseptal defibrillator lead positioning. A 12-lead electrocardiogram was recorded during intrinsic rhythm and RV pacing. Paced RBBB-like pattern was defined as positive (>0.05mV) net amplitude of QRS complex in leads V1 and/or V2. In total, 226 patients (65.6 ± 12.0years, 20.8% women, 53.1% apical site) were included in the study. The prevalence of paced RBBB pattern in the total population was 15.5%. A significantly lower percentage of patients in the midseptal group demonstrated RBBB-type configuration during RV pacing compared with the apical group (1.9% vs 27.5%, p <0.001). Baseline RBBB, prolonged QRS duration during intrinsic rhythm, and reduced ejection fraction were not associated with increased likelihood of paced RBBB. In the subgroup of patients with RBBB type during pacing, 91.4% of patients had a paced QRS axis from-30° to-90°, whereas 100% of patients displayed a negative QRS vector at lead V3. In conclusion, RBBB configuration is encountered in a considerable percentage of device recipients during uncomplicated RV pacing. Midseptal lead positioning is associated with significantly lower likelihood of paced RBBB pattern compared with apical location.

Acute myeloid leukemia of mixed megakaryocytic and erythroid origin following chemotherapy for T-cell lymphoblastic lymphoma

A 14-year-old boy was admitted for fever of 3-day duration, and palpable masses in his left axilla and breast for 1 month. Four years prior to admission, he had been diagnosed with mediastinal T-lymphoblastic lymphoma without evidence of bone marrow (BM) involvement, and had received induction chemotherapy with dexamethasone, vincristine, daunorubicin, and L-asparaginase, resulting in complete remission. The patient had completed subsequent phases of consolidation and maintenance treatment and had been off treatment for 18 months before admission. On admission, PB revealed a white blood cell count of 44.07 9 10/L, a hemoglobin level of 14.3 g/dL and a platelet count of 154 9 10/L. Serum levels of lactate dehydrogenase (LDH) and uric acid were elevated to 7,490 U/L and 10.9 mg/dL, respectively. Other laboratory findings were as follows: C-reactive protein 1.78 mg/dL, AST 126 U/L, and fibrinogen [500 mg/dL. PET/CT showed increased FDG uptake in the neck, axilla, and anterior chest wall, which had not been observed at the onset of lymphoma. PB smear showed a predominance of blast cells (about 70 %). Subsequently, BM aspirate revealed 100 % cellularity with a high percentage of blasts, which accounted for 91 % of all nucleated cells (Fig. 1a, b). The medium to large-sized blasts were round to oval shaped, with finely chromatinated nuclei with or without distinct nucleoli, and scant to moderate amounts of blue cytoplasm containing some vacuoles. The blasts were dysplastic with megaloblastoid nuclei and/or bi-or multinucleated forms. They showed positivity for periodic acid-Schiff (PAS) stain in a block-like staining pattern, but were negative for myeloperoxidase (MPO) and a-naphthyl butyrate esterase (ANBE) stains (Fig. 1c). Immunohistochemistry showed that immature blasts in the BM were negative for CD61 (Fig. 1d). Immunophenotypic analysis by flow cytometry revealed that the majority of blast population was positive for CD33 and CD41a. A small portion was also positive for CD235a (glycophorin A), CD2, CD11c, CD13, and CD14. Other antigens, including CD5, CD7, CD10, CD19, CD20, CD22, CD34, CD56, CD64, CD117, cytoplasmic CD3, cytoplasmic MPO, HLA-DR, and cytoplasmic CD79a were not detectably expressed (Fig. 1e). Cytogenetic analysis of the bone marrow cells using the Giemsa banding technique revealed the karyotype 47,XY,?8,t(12;20)(p13;q13.1)[18]/46,XY[2] (Fig. 1f). FISH analysis for the RUNX1–RUNX1T1 rearrangement revealed no fusion signal, but three signals for RUNX1T1 in 90 % of the analyzed cells. Results of FISH performed using BCR-ABL1, PML-RARA, CBFB, MLL, 5q, and 7q31 probes and HemaVision (DNA Technology, Aarhus, Denmark) screening were negative. The disease was primarily classified as a therapy-related myeloid neoplasm according to the 2008 WHO classification and the secondary diagnosis of acute myeloid leukemia of mixed megakaryocytic and erythroid origin was also made based on the combination of morphology and immunophenotypic and cytochemical findings. The patient received induction chemotherapy with cytarabine and W. Jang M. Kim (&) Department of Laboratory Medicine, The Catholic University of Korea, Seoul, Korea e-mail: microkim@catholic.ac.kr

Electrocardiographic algorithms to predict true right ventricular pacing in the presence of right bundle branch block-like pattern

Electrocardiographic algorithms to predict true right ventricular pacing in the presence of right bundle branch block-like pattern

Phacomatosis melanorosea, unearthed

ejd.2012.1749 Auteur(s) : Daniele Torchia daniele.torchia@unifi.it Via della Scala 58, 50123 Florence, Italy Reprint: D. Torchia Two recent EJD reports described two cases characterized by an allegedly undescribed association between a large hypermelanotic macule of cafe-au lait color (HM) and naevus roseus (NR), both occurring in a block-like pattern reminiscent of cutaneous mosaicism [1, 2]. This condition was named “phacomatosis melanovascularis” [1] or, more appropriately, “phacomatosis melanorosea” [...]

Drying dissipative patterns of aqueous solutions of simple electrolytes and their binary mixtures on a cover glass

The drying dissipative patterns of aqueous solutions of simple electrolytes, KCl, NaCl, CaCl2, and LaCl3, were observed on a cover glass. The macroscopic broad rings were formed at the outside edge of the drying film area, which shrunk from the initial solution area especially at low salt concentrations. The drying area and the broad ring size decreased as the salt concentration decreased. The microscopic block-like and dendritic cross-like patterns were observed for all the salts. Size of single crystals dried on a cover glass increased as salt concentration increased. The drying patterns of the binary mixtures of the salts were also observed. Size of the broad ring increased sharply by mixing. The microscopic patterns were, on the other hand, insensitive to the mixing.

Drying dissipative patterns of biological polyelectrolyte solutions

Drying dissipative structural patterns of aqueous solutions of biological polyelectrolytes, sodium poly (α, L-glutamate; NaPGA) and poly (-L-lysine hydrobromide; PLL.HBr), were studied on a cover glass. Below the critical polymer concentration, m* (ca. 0.003 and ca. 0.01 monoM for NaPGA and PLL.HBr, respectively), the dried patterns shrank only around the center of the initial solution area wetted on a cover glass. Above the m* values, on the other hand, the drying pattern extended throughout the initial solution area. The m* values agreed excellently with the critical polymer concentrations, where the surface tensions started to decrease sharply as the polymer concentrations increased. The broad rings were always observed in the drying patterns of any solutions examined. The spoke-like cracks appeared at the polymer concentrations above the m* values and only in the area of the broad rings. Microscopic structures such as cross-like, rod-like, and block-like patterns formed irrespective of polymer concentrations. Especially, the city-road-like microscopic pattern was observed for PLL.HBr solutions, which strongly supports the formation of crystal structures of PLL.HBr that remain in the whole processes of dryness. These patterns were correlated deeply with the crystal-like orientation of the biological polyelectrolytes at the air–solution interfaces.

Significant variation in haplotype block structure but conservation in tagSNP patterns among global populations

The initial belief that haplotype block boundaries and haplotypes were largely shared across populations was a foundation for constructing a haplotype map of the human genome using common SNP markers. The HapMap data document the generality of a block-like pattern of linkage disequilibrium (LD) with regions of low and high haplotype diversity but differences among the populations. Studies of many additional populations demonstrate that LD patterns can be highly variable among populations both across and within geographic regions. Because of this variation, emphasis has shifted to the generalizability of tagSNPs, those SNPs that capture the bulk of variation in a region. We have examined the LD and tagSNP patterns based upon over 2000 individual samples in 38 populations and 134 SNPs in 10 genetically independent loci for a total of 517 kb with an average density of 1 SNP/5 kb. Four different 'block' definitions and the pairwise LD tagSNP selection algorithm have been applied. Our results not only confirm large variation in block partition among populations from different regions (agreeing with previous studies including the HapMap) but also show that significant variation can occur among populations within geographic regions. None of the block-defining algorithms produces a consistent pattern within or across all geographic groups. In contrast, tagSNP transferability is much greater than the similarity of LD patterns and, although not perfect, some generalizations of transferability are possible. The analyses show an asymmetric pattern of tagSNP transferability coinciding with the subsetting of variation attributed to the spread of modern humans around the world.

Large aberrant Mongolian spots coexisting with cutis marmorata telangiectatica congenita (phacomatosis pigmentovascularis type V or phacomatosis cesiomarmorata)

A 1-month-old boy showed cutis marmorata telangiectatica congenita (CMTC) involving a block-like pattern on his left leg and thigh and on the left side of his trunk, along with bilateral greyish-blue hyperpigmentation involving the buttocks and thighs and being in part intermingled with CMTC. This association of CMTC with Mongolian spots has been reported as a distinct type of phacomatosis pigmentovascularis (PPV), namely PPV type V. More recently, the term phacomatosis cesiomarmorata (cesius = blue) has been proposed. We believe phacomatosis cesiomarmorata is another example of twin spotting or didymosis.

Aortic Endocarditis Caused by Inadvertent Left Ventricular Pacemaker Lead Placement

An 82-year-old man complained of lassitude, sweating, and fever for &5 weeks. On physical examination, a new 3/6 diastolic murmur was heard at the left sternal border, and the patient was admitted with suspected endocarditis. The patient’s history revealed a VVI pacemaker implantation 9 months earlier for unspecified bradycardia at another institution and a transient ischemic attack 2 months before admission. On admission, C-reactive protein was elevated at 68.6 mg/L, and Staphylococcus epidermidis was isolated in several blood cultures. The frontal and lateral views (Figure 1A and 1B) of a chest radiograph showed inadvertent pacemaker lead malpositioning into the left ventricle. Additionally, the right bundle-branch block-like pattern of a paced ECG (Figure 2) gave concern of lead malpositioning. Transthoracic echocardiography confirmed the malpositioning of the pacemaker lead into the left ventricle and …

SNP microarray analysis for genome-wide detection of crossover regions

There is a great deal of interest in understanding the non-random distribution of recombination events over the human genome, because it has important implications for using linkage disequilibrium (LD) to identify human disease genes. So far, only a few recombination hotspots in the human genome have been characterised and the identification of new crossover hotspots will contribute to a better understanding of the mechanisms that govern their formation and distribution. This study shows that high-density single nucleotide polymorphism (SNP) arrays, together with the presented analysis method, are an appropriate tool for generating a whole-genome recombination pattern and for detecting new crossover regions with enhanced recombination frequency. Based on the genotype data of 16 members of a Caucasian three-generation family, we identified 825 crossover regions. The average recombination frequency of females and males was 0.77 and 0.56 cM/Mb, respectively. We detected 24 crossover regions showing elevated recombination activity, which comprised known hotspots, like the MHC II region, confirming the non-random distribution of recombination events along the genome. Interestingly, 29.2% of the identified crossover hotspot regions overlapped with regions flanked by segmental duplications published by Bailey et al. (Science 297:1003-1007, 2002) suggesting that segmental duplications and crossover hotspot regions are mechanistically linked. By extrapolating the results of the present study, we conclude that it might be feasible, at least in part, to estimate to what extent the block-like pattern of LD exactly relies on the genome-wide crossover pattern using the next generation high-density SNP microarrays.

Population-Genetic Basis of Haplotype Blocks in the 5q31 Region

We investigated patterns of nucleotide variation in the 5q31 region identified by Daly et al. as containing haplotype blocks, to determine whether the blocklike pattern requires the assumption of hotspots in recombination. Using extensive simulations that generate data matched to the Daly et al. data set in (a) the method of ascertainment of single-nucleotide polymorphisms, (b) the heterozygosity of ascertained markers, (c) the number of block boundaries, and (d) the diversity of haplotypes within blocks, we show that the patterns found in the Daly et al. data are not consistent with the assumption of uniform recombination in a population of constant size but are consistent either with the presence of hotspots in a population of constant size or with the absence of hotspots if there was a period of rapid population growth. We further show that estimates of local recombination rate can distinguish between population growth and hotspots as the primary cause of a blocklike pattern. Estimates of local recombination rates for the Daly et al. data do not indicate the presence of recombination hotspots.

Randomly distributed crossovers may generate block-like patterns of linkage disequilibrium: an act of genetic drift

There is considerable interest in identifying and characterizing block-like patterns of linkage disequilibrium (LD; haplotype blocks) in the human genome as these may facilitate the identification of complex disease genes via genome-wide association studies. Although recombination hot-spots have been suggested as the primary mechanism to explain the block-like pattern of LD, other forces, such as genetic drift, may also be important. To this end, we have studied the effect of various recombination models on patterns of LD by using extensive simulations. As expected, haplotype blocks were observed under a model allowing recombination hot-spots. However, we also observed similar block-like patterns in the models where recombination crossovers are randomly and uniformly distributed, and we demonstrate that these blocks are generated by genetic drift. We caution that genetic drift may be an alternative mechanism (in addition to recombination hot-spots) that can lead to block-like patterns of LD. Our findings highlight the necessity of characterizing haplotype blocks in world-wide populations.

&lt;i&gt;Acrobeles farzanae&lt;/i&gt; spec. nov. and &lt;i&gt;Seleborca complexa&lt;/i&gt; (Thorne) from the West Coast National Park and Rocher Pan Nature Reserve (Nematoda: ephalobidae)

Acrobeles fananae spec. nov. is described from two localities on the west coast of South Africa. The new species is characterised by body length of 0.7-0.8 mm; relatively slender, cylindroid body, abruptly ventrally bent in vulval region; vulva with protruding lips and situated in a sunken area; three incisures in lateral field; and cuticle with an intricate interlocked block-like pattern. Additional data is presented on the morphology of Seleborca complexa (Thorne, 1925) collected in the same area.

SEISMOTECTONIC IMPLICATION OF SEISMICITY PATTERN

Seismicity pattern represents the characteristics of a group of earthquakes. This paper describes several characteristic features of seismicity in China's mainland, especially in North China. They include block-like distribution of earthquakes, temporal correlation of seismic activities of given separate regions, repeat of certain seismicity pattern in space, etc. The spatial dimension of these patterns may reach hundreds or thousands of kilometers. Accordingly, the dynamic force causing earthquakes is suggested to act simultaneously on a large area. Earthquakes in China's mainland are mainly concentrated in a layer of 15-km thickness, i.e., the competent seismogenic layer. Because of the large difference between this thickness and the large horizontal dimension of seismicity pattern, the seismogenic layer can be considered as a thin shell. Since observed block-like seismicity pattern is very similar to the buckling pattern of a thin shell, we suggest that block-like pattern of seismicity is caused by the buckling of the seismogenic layer. The calculated dimension of the buckling pattern is about 500 km and it well agrees with the dimension of blocks.

Quaternary volcanic and tectonic segmentation of Central America

Central America is divided into seven segments based on differences in the strikes and positions of volcanic lineaments in the historically active volcanic chain. This block-like pattern is also seen in the contrasting volcano morphology, recent fault patterns and the distribution of shallow earthquakes. Discontinuities in the deep seismic zone can be identified at some segment margins. The boundary areas between the segments are characterized by faulting transverse to the volcanic lineaments, frequently accompanied by basalt cinder cone fields, by concentrations of shallow earthquakes and by catastrophic historic eruptions. This volcanological, structural and seismological data can be explained by a segmented converging plate margin. At shallow depths the underthrust lithosphere is broken along tear faults into 100 to 300 km long segments. The separate segments descend into the mantle with different strikes and dips and give the geology its segmented character. Evidence for similar segmented converging plate margins is found in Mexico and in other parts of the circumpacific and alpine belts.