(C) 2011 AEC Published by Elsevier Espana, S L All rights rese

(C) 2011 AEC. Published by Elsevier Espana, S. L. All rights reserved.”
“We GSK461364 cell line have developed and characterized 21 microsatellite markers in the aphidophagous gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). All 21 loci tested were polymorphic: the number of alleles ranged from 2 to 17. Allelic richness and observed heterozygosities were higher in females than in males. Several loci had no heterozygosity in males, suggesting that the loci were located on sex chromosomes or E-chromosomes, common to cecidomyiids. The high polymorphism detected in this study suggests the markers will

be of value in analyzing genetic structure of field populations.”
“Mixed phenotype acute leukemia (MPAL) in adults represents nearly 2 to 5 % of all acute leukemia cases. There are two large studies throughout the world and only case reports and small series have been reported in Latin America. This study retrospectively analyses

Z-VAD-FMK ic50 the clinical characteristics and survival of 27 patients with MPAL evaluated in three medical institutions of Mexico. All cases meet World Health Organization 2008 criteria; 70.3 % of patients had B lymphoid/myeloid lineage MPAL. Induction chemotherapy protocols included 7 + 3 hyper-CVAD, high-density schedules, and pediatric-like regimens such as New York II and total XI. Complete remission was achieved in 23/27 patients (85.2 %). Only one patient died due to chemotherapy-induced aplasia during remission induction (5.2 %). In 68 % of cases, we were able to administer maintenance

therapy as a regimen in lymphoblastic leukemia. At the time of analysis, 70.4 % of the patients in the entire cohort had died mainly as result of disease progression (73.6 %). Disease-free survival was 13 months (95 % CI, 9.6-16.3 months) and overall survival was 14.8 months (95 % CI 13.4-16.27). Survival rates Cyclosporin A ic50 are low and standardized therapy for the management of this type of leukemia is still lacking. This is the largest series reported in Mexico and to the best of our knowledge in Latin America.”
“OBJECTIVE: This study investigated the serological status of dogs living in a visceral leishmaniasis-endemic area and its correlation with the parasitological condition of the animals. METHODS: Canine humoral response was evaluated using the sera of 134 dogs by enzyme-linked immunosorbent assay and immunohistochemistry to detect parasites in the skin, lymph node, and spleen of the animals. The specific antibodies investigated were IgG, IgG1, IgG2, and IgE. RESULTS: According to the parasitological, laboratory, and clinical findings, the dogs were placed into one of four groups: asymptomatic with (AP+, n = 21) or without (AP-, n = 36) Leishmania tissue parasitism and symptomatic with (SP+, n = 52) or without (SP-, n = 25) parasitism. Higher IgG and IgE levels were positively correlated with the infection condition and parasite load, but not with the clinical status.

5 +/- 16 4 ng/mL) than lower (19 0 +/- 13 5 ng/mL) grades The Cu

5 +/- 16.4 ng/mL) than lower (19.0 +/- 13.5 ng/mL) grades. The Cu level was unaffected by sex and age in the sound teeth group. The Cu level in children with caries experience (5.7 +/- 5.3 ng/mL) was significantly higher than that of the sound teeth group. Moreover,

the Cu levels in children with untreated caries were significantly higher than that of the sound teeth group, and increased with the number of untreated teeth. No significant difference was found in the Cu concentrations between the group in which all decayed teeth were treated and the sound teeth group. The Mn levels were similar with or Compound C inhibitor without caries and treatment. These findings indicate that the Mn level in mixed saliva depended on sex and age, and suggest the possibility of Cu dissolving into mixed saliva by demineralization due to dental caries. (C) 2009 Elsevier GmbH. All rights reserved.”
“Stroke or cerebrovascular accident is the second most common cause of death in Western countries. Although stroke is a treatable disease, the majority of patients do not receive intravenous thrombolysis or catheter-based therapy. The lack of treatment is multifactorial. Several treatments have been studied. Research and development in the area of acute stroke treatment

selleck compound are ongoing.\n\n(J Interven Cardiol 2009;22:1-8).”
“Dendrochronological research in Southeast Asia is under development; however, the amount of tress with potential for dendrochronological studies is restricted. For example, teak trees from India, Myanmar, Thailand, and Java are valuable dendrochronologic studies for ready climate response. Teak from Java is best suited for studying the El Nio-Southern Oscillation and sea-surface temperatures, whereas Indian teak is used to reconstruct periods of drought in India. Further, Thai teak and Vietnamese cypress trees captured the long drought period that led to the demise of the Angkor reign (fourteenth-fifteenth century). Diverse techniques including anatomical observation, cambial markings, cell differentiation, and isotopic analysis prove the age and growth of invisible

tropical tree rings. A number of invisible growth rings in trees from both tropical and subtropical forests have been identified, resulting in the advancement of dendrochronology. Climate change is a substantial challenge for most living LDK378 things and natural resources. A greater understanding of tree species adaptation in this region is necessary. The understanding of long-term paleoclimate can be gained by researching old samples and archaeological materials from this region.”
“Background: Rotenone is an environmental neurotoxin that induces accumulation of alpha-synuclein and degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc), but the molecular mechanisms are not fully understood. We investigated whether rotenone induced impairment of autophagic flux and lysosomal functions.


the intestine generally absorbs oxalate from die


the intestine generally absorbs oxalate from dietary sources and can contribute as much as 50% of urinary oxalate, enteric oxalate elimination plays a significant role when renal function is compromised. Stem Cell Compound Library in vitro While the mechanistic basis for these changes in the direction of intestinal oxalate movements in chronic renal failure involves an upregulation of angiotensin II receptors in the large intestine, enteric secretion/excretion of oxalate can also occur by mechanisms that are independent of angiotensin II. Most notably, the commensal bacterium Oxalobacter sp. interacts with the host enterocyte and promotes the movement of oxalate from the blood into the lumen, resulting in the beneficial effect of significantly lowering urinary oxalate excretion. Changes in the passive permeability

of the intestine, such as in steatorrhoea and following gastric bypass, also promote oxalate absorption and hyperoxaluria. In summary, this report highlights the two-way physiological signalling between the gut and the kidney, which may help to alleviate the consequences of certain kidney diseases.”
“Nonhuman primates are useful animal models for the study of human diseases. However, the number of established cell lines from nonhuman 17DMAG Cytoskeletal Signaling inhibitor primates is quite limited compared with the number established from other experimental animals. The establishment of nonhuman primate cell lines would allow drug testing on those cell lines before moving experiments into primates. In this

study, we established nonhuman primate primary cell lines by introducing the genes for CDK4R24C, cyclin D1, and hTERT. These cell lines proliferated more rapidly than primary cells and bypassed cellular senescence. Karyotype analysis showed that the chromosome patterns were intact in the immortalized cell lines. Furthermore, we showed that the expression of introduced selleck inhibitor genes could be precisely controlled through the Tet-Off system with the addition of doxycycline. The present study shows that introduction of the CDK4R24C, cyclin D1, and hTERT genes are effective methods of establishing nonhuman primate cell lines. (C) 2014 Wiley Periodicals, Inc.”
“The adaptor protein p66Shc regulates intracellular oxidant levels through the modulation of a forkhead-related transcription factor (FOXO3a). The genetic ablation of p66(Shc) (p66(Shc-/-)) renders mice resistant to oxidative stress and p53-dependent apoptosis. We investigated whether p66(Shc) ablation in mice modifies lung cellular and molecular responses to cigarette smoke (CS) exposure. No differences between wild type (WT) and p66(Shc-/-) mice were observed in terms of inflammation and oxidant burden after acute CS exposure; however, p66(Shc) ablation modifies specific features of chronic inflammation induced by repeated exposure to CS.

“Schizophrenia is a highly heritable and polygenic disease

“Schizophrenia is a highly heritable and polygenic disease, and identified common genetic variants have

shown weak individual effects. Many studies have reported altered working memory (WM)-related brain activation in schizophrenia, preferentially in the frontal lobe. Such differences in brain activations could reflect inherited alterations possibly involved in the disease etiology, or rather secondary disease-related mechanisms. The use of polygenic FLT3 inhibitor risk scores (PGRS) based on a large number of risk polymorphisms with small effects is a valuable approach to examine the effect of cumulative genetic risk on brain functioning. This study examined the impact of cumulative genetic risk for schizophrenia on WM-related brain activations, assessed with functional magnetic resonance imaging. For each participant (63 schizophrenia buy PND-1186 patients and 118 healthy controls), we calculated a PGRS for schizophrenia based on 18 862 single-nucleotide polymorphism in a large multicenter genome-wide association study including 9146 schizophrenia patients and 12 111 controls, performed by the Psychiatric Genomics Consortium. As expected, the PGRS was significantly higher in patients

compared with healthy controls. Further, the PGRS was related to differences in frontal lobe brain activation between high and low WM demand. Specifically, even in absence of main effects of diagnosis, increased PGRS was associated with decreased activation difference in the right middle-superior prefrontal cortex (BA 10/11) and the right inferior Acalabrutinib supplier frontal gyrus (BA 45). This effect was seen in both cases and controls, and was not influenced by sex, age, or task performance. The findings support the notion of dysregulation of frontal lobe functioning as an inherited vulnerability factor in schizophrenia.”
“In 2000 to 2001, 2003 to 2004, and 2005 to 2006, three outbreaks of Salmonella enterica serovar Enteritidis

were linked with the consumption of raw almonds. The S. Enteritidis strains from these outbreaks had rare phage types (PT), PT30 and PT9c. Clinical and environmental S. Enteritidis strains were subjected to pulsed-field gel electrophoresis (PFGE), multilocus variable-number tandem repeat analysis (MLVA), and DNA microarray-based comparative genomic indexing (CGI) to evaluate their genetic relatedness. All three methods differentiated these S. Enteritidis strains in a manner that correlated with PT. The CGI analysis confirmed that the majority of the differences between the S. Enteritidis PT9c and PT30 strains corresponded to bacteriophage-related genes present in the sequenced genomes of S. Enteritidis PT4 and S. enterica serovar Typhimurium LT2. However, PFGE, MLVA, and CGI failed to discriminate between S. Enteritidis PT30 strains related to outbreaks from unrelated clinical strains or between strains separated by up to 5 years. However, metabolic fingerprinting demonstrated that S.

“Mutations in the gene encoding adenosine deaminase (ADA),

“Mutations in the gene encoding adenosine deaminase (ADA), a purine salvage enzyme, lead to immunodeficiency in humans. Although ADA deficiency has been analyzed in cell culture and murine models, information is lacking

concerning its impact on the development of human thymocytes. We have used chimeric human/mouse fetal thymic organ culture to study ADA-deficient human thymocyte development in an “in vivo-like” environment where toxic metabolites accumulate in situ. Inhibition check details of ADA during human thymocyte development resulted in a severe reduction in cellular expansion as well as impaired differentiation, largely affecting mature thymocyte populations. Thymocyte differentiation was not blocked at a discrete stage; rather, the paucity of mature thymocytes was due to the induction of apoptosis as evidenced by activation of caspases and was accompanied by the accumulation of intracellular dATP. Inhibition of adenosine kinase and deoxycytidine kinase

prevented the accumulation of dATP and restored thymocyte differentiation and proliferation. Our work reveals that multiple deoxynucleoside kinases are involved in the phosphorylation of deoxyadenosine when ADA is absent, and this website suggests an alternate therapeutic strategy for treatment of ADA-deficient patients. The Journal of Immunology, 2008, 181: 8153-8161.”
“Alexithymia is found in up to 10% of the general population and is associated with lower quality of life. Alexithymia is a major risk factor for a range of medical and psychiatric problems. Although a deficit involving the anterior cingulate cortex (ACC) deficit is thought

LY2090314 research buy to offer the most promising neurobiological model of alexithymia, current studies have yielded inconsistent findings. In this study, neural activity was investigated in well-controlled alexithymic individuals subjected to emotional stimuli. Fifteen individuals with high Toronto Alexithymia Scale (TAS-20) scores (high-alexithymic group) and 15 individuals with low TAS-20 scores (low-alexithymic group) were screened from 432 female college students. Depressive and anxious behaviors were scored using self-rating depression scale (SDS) and self-rating anxiety scale (SAS) questionnaires, respectively. Emotional stimuli consisted of pictures with positive, negative, or neutral pleasantness and high or low arousal of emotional intensity. Regional cerebral activation was measured by functional magnetic resonance imaging (fMRI). The anterior cingulate, mediofrontal cortices, insula and temporal lobe were significantly activated by intense emotional stimuli (negative or positive pictures) in high-alexithymic individuals compared to low-alexithymic individuals. Conversely, high-alexithymic and low-alexithymic individuals showed similar brain activity when subjected to neutral stimuli. Alexithymia is associated with activation in anterior cingulate and mediofrontal cortices during emotional stimuli processing.

Discussion Young people’s

Discussion Young people’s Quizartinib manufacturer experiences demonstrate the importance of moving beyond viewing health choices as technical or rational decisions. How

each young person framed their decision was important. Recognizing this diversity and the importance of emerging themes, such as living a normal life, independence, fear of decisions viewed as irreversible’ and the role of parents and peers in decision making highlights that, there are clear practice implications including, active practitioner listening, sensitivity and continued holistic family working.”
“The aim of this research was to evaluate the influence of cold stabilisation treatment and chill membrane filtration on apricot brandy’s stability and its volatile compounds. Cold

stabilisation treatment included exposure of the brandy to the temperature of -1 degrees C during 24 h. Membranes with pore sizes of 200, 450 and 800 nm were used in this study. The content of fatty acid esters (ethyl palmitate, ethyl laurate), the main causes of chill haze in strong alcoholic drinks, was efficiently reduced by all tested membranes. Content of alcohols, aldehydes and terpenes (except nerol) was not significantly influenced by applied treatments. All the brandy samples were stable after the re-exposure to lower temperatures. The sample filtered through the 800 nm pore size membrane showed the best sensory characteristics, most similar selleck chemicals llc to the control sample. (C) 2013 The Institution of Chemical Engineers. Published by Elsevier

B.V. All rights reserved.”
“Objective. To describe the learning curve associated with training fellows in completing robotic assisted total laparoscopic hysterectomies. Methods. All patients scheduled to undergo a robotic procedure at our institution from 5/15/07 to 5/22/12 were identified. Fellow participation per procedure was documented. The learning curve of fellows for the time to complete a hysterectomy (from initiation of developing the retroperitoneal space to the completion of the colpotomy) Z VAD FMK was analyzed. Results. Of the 1754 planned robotic cases, 1626 were completed robotically and 128 were converted to laparotomy. Fifty-seven fellows participated in 99.7% of the cases. Eleven gynecologic oncology fellows completed at least 1 robotic assisted total laparoscopic hysterectomy. From 7/7/08 to 5/21/12, 981 hysterectomies were completed robotically, 254 of these (25.9%) by the 11 fellows. Prior to completing a hysterectomy, the median number of hysterectomies in which a fellow participated was 16 (range, 11-40). Median amount of time for a fellow to complete a hysterectomy decreased from 60 min in 2009 (N = 27 cases) to 31 min in 2011 (N = 148 cases). Based on the recorded completion times in which the 11 fellows completed a hysterectomy, it required similar to 33 cases per fellow to be able to perform the hysterectomy and overcome the learning curve. Conclusions.

Specific mutational effects included N33A in TMD I causing an inc

Specific mutational effects included N33A in TMD I causing an increase in gamma-secretase complexes at the cell surface and a modest decrease in stability and the previously unreported I53A mutation in the loop region reducing stability 10-fold and proteolytic activity by half. In addition, we confirm that minor PS1 endoproteolysis can occur in the complete absence of Pen-2. Together, these data suggest that rather than solely being a catalyst for gamma-secretase endoproteolysis, Pen-2 may also stabilize the complex prior to PSI endoproteolysis,

allowing time for full assembly and proper trafficking.”
“Neonatology, the care and study of newborn infants, is a ‘young’ specialty. Over buy AZD6244 the last 50 years, there have been many advances in the way that neonatologists care for newborn infants, particularly those born preterm, leading to dramatic improvements in mortality. To illustrate these advances, we describe four eras in neonatology from the point of view of the junior hospital doctor.”
“Background Those interested in evaluating the effectiveness of community interventions on health and well-being need information about what tools

are available and best suited to measure improvements that could be attributed to the intervention. buy β-Nicotinamide This study evaluated published measurement tools of health and well-being that have the potential to be used before and after an intervention. Methods A literature search of health and sociological databases was undertaken for articles that utilised measurement tools in community learn more settings to measure overall health, well-being or quality of life. Articles were considered potentially relevant because they included use of measurement tools related to general health or wellbeing. These tools were evaluated by further searching of the literature to assess each tool’s properties including: reliability; validity; responsiveness; length; use in cross-cultural settings; global health

or well-being assessment; use of subjective measures; clarity and cost. A composite score was made based on the average rating of all fields. Results Of 958 abstracts that were screened, 123 articles were extracted for review. From those articles, 27 measurement tools were selected and assessed. Based on the composite score assessing across all domains, five tools were rated as excellent. Conclusions While tools may need to be selected for particular aims and interventions, a range of potential well-described tools already exist and should be considered for use in preference to ad hoc or bespoke tools. Any of the five tools rated as excellent are recommended to assess the impact of a community intervention.”
“Cerebral microvascular endothelial cells play an active role in maintaining cerebral blood flow, microvascular tone and blood brain barrier (BBB) functions.

Of the microRNAs identified, more than 100 are unique amongst ver

Of the microRNAs identified, more than 100 are unique amongst vertebrates, including a subset containing mutations in critical seed regions. Clusters of rapidly-evolving CP 456773 microRNAs were identified, as well as microRNAs predicted to target genes involved in antiviral immunity, the DNA damage response, apoptosis and autophagy. Closer inspection of the predicted targets for several highly supported novel miRNA candidates suggests putative roles in host-virus

interaction. Conclusions: MicroRNAs are likely to play major roles in regulating virus-host interaction in bats, via dampening of inflammatory responses (limiting the effects of immunopathology), and directly limiting the extent of viral replication, either through restricting the availability of essential factors or by controlling apoptosis. learn more Characterisation of the bat microRNA repertoire is an essential step towards understanding transcriptional regulation during viral infection, and will assist in the identification of mechanisms that enable bats to act as natural virus reservoirs. This in turn will facilitate the development of antiviral strategies

for use in humans and other species.”
“Background: Whether patients with small ( smaller than 2 cm), sporadic nonfunctioning pancreatic endocrine tumors (NF-PETs) should directly undergo pancreatic surgery or should be followed longitudinally to detect growth and malignancy still has to be defined. Study Design: Based on the pertinent literature of the past decade, a Markov model was developed to investigate this

issue. In the wait-and-see strategy arm, surgery was performed if the tumor attained a size bigger than = 2 cm or surpassed 20% of the initial size. In a Monte Carlo probabilistic analysis, 100 hypothetical patients undergoing a wait-and-see strategy were compared to 100 patients directly undergoing surgery, with the aim of investigating the efficacy Trichostatin A nmr and cost-effectiveness of the two strategies. Results: During the postdiagnostic lifetime, 63 NF-PETs in the wait-and-see group showed significant growth and underwent surgery: 38 were stage I, 10 were stage II, 15 were stage III and none were stage IV. In the base-case scenario, the mean life expectancy and quality-adjusted life expectancy were found to be superior after immediate surgery [26.1 years and 11.8 quality-adjusted life years (QALYs)] than with the wait-and-see strategy (22.1 years and 8.3 QALYs) as the consequence of ageing during the wait-and-see follow-up which increased mortality due to surgery, when surgery was needed. The model was sensitive to starting age and length of follow-up; in particular, for patients bigger than 65 years of age, the two strategies provided similar results but the wait-and-see strategy was more cost-effective.

“We examined the expression of ezrin and moesin


“We examined the expression of ezrin and moesin

in laryngeal squamous cell carcinoma (LSCC) and their correlation with patient clinicopathological characteristics and overall survival. Immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) for ezrin and moesin were applied to 60 carcinoma tissues, adjacent normal tissues, and 33 metastatic lymph nodes. Survival functions were estimated using the Kaplan-Meier method and compared by the log-rank test. RT-PCR demonstrated that the intensity ratios of ezrin and moesin to beta-actin were higher in LSCC than in adjacent normal mucous membrane (P smaller than 0.05). Furthermore, intensity ratios were this website higher in cervical metastatic lymph nodes than in LSCC (P smaller than 0.05). Immunohistochemical staining showed that ezrin and moesin were well distributed in the cell membrane and cytoplasm. C59 price Expression was significantly different between LSCC and adjacent normal tissues (P smaller than 0.05); moreover, expression in the cervical metastatic

lymph nodes was higher than in LSCC (P smaller than 0.05). Expression of ezrin and moesin was significantly related to clinical stage, T stage, and cervical lymph node metastasis (P smaller than 0.05), except that moesin showed no significant relationship with clinical stage (P bigger than 0.05). Patients with negative ezrin and moesin expression had a significantly longer overall survival time compared to patients with moderate and intense ezrin and moesin expression (P smaller than 0.001, P smaller than 0.05). Ezrin and moesin expression is related

to LSCC invasion and metastasis, and may be important molecular markers for predicting prognosis and therapeutic targets in LSCC patients.”
“Influenza A(H3N2) virus was detected in oral fluid from 16/107 children (aged 2 to 12 years) with a clinical diagnosis of mumps, who were sampled between December 2014 and February 2015 in England, during the peak of the 2014/15 influenza season. Sequence analysis of an A(H3N2) virus from a child with suspected mumps showed the virus was similar to PKC412 clinical trial other circulating A(H3N2) viruses detected in winter 2014/15, which were antigenically drifted from the A(H3N2) vaccine strain.”
“Background: Several studies have applied low-frequency repetitive transcranial magnetic stimulation (rTMS) directed at the left temporoparietal area (TP) for the treatment of auditory verbal hallucinations (AVH), but findings on efficacy are inconsistent. Furthermore, recent functional magnetic resonance imaging (fMRI) studies indicate that the left TP is not a general focus of activation during the experience of AVH.

In this pathway, PINK1 accumulates on defective mitochondria, eli

In this pathway, PINK1 accumulates on defective mitochondria, eliciting the translocation of PARKIN from the cytosol to mediate the clearance of damaged mitochondria via autophagy (mitophagy). Throughout the different stages of mitophagy, post-translational modifications (PTMs) are critical for the regulation of PINK1 and PARKIN activity and function. Indeed, activation and recruitment of PARKIN onto damaged mitochondria involves PINK1-mediated phosphorylation of both PARKIN and Ub. Through a stepwise cascade, PARKIN is converted from an autoinhibited

enzyme into an active phospho-Ub-dependent E3 ligase. Upon activation, PARKIN ubiquitinates itself in concert with many different mitochondrial substrates. The Ub conjugates attached to GW786034 clinical trial these substrates can in turn be phosphorylated by PINK1, which triggers further Vactosertib cycles of PARKIN recruitment and activation. This feed-forward amplification loop regulates both PARKIN activity and mitophagy. However, the precise steps and sequence of PTMs in this cascade are only now being uncovered. For

instance, the Ub conjugates assembled by PARKIN consist predominantly of noncanonical K6-linked Ub chains. Moreover, these modifications are reversible and can be disassembled by deubiquitinating enzymes (DUBs), including Ub-specific protease 8 (USP8), USP15, and USP30. However, PINK1-mediated phosphorylation of Ub can impede the activity of these DUBs, adding a new layer of complexity to the regulation of PARKIN-mediated mitophagy by PTMs. It is therefore

evident that further insight into how PTMs regulate the PINK1-PARKIN pathway will be critical for our understanding of mitochondrial quality control.”
“Brook trout Salvelinus fontinalis (Mitchill, 1814) chromosomes Birinapant have been analyzed using conventional and molecular cytogenetic techniques enabling characteristics and chromosomal location of heterochromatin, nucleolus organizer regions (NORs), ribosomal RNA-encoding genes and telomeric DNA sequences. The C-banding and chromosome digestion with the restriction endonucleases demonstrated distribution and heterogeneity of the heterochromatin in the brook trout genome. DNA sequences of the ribosomal RNA genes, namely the nucleolus-forming 28S (major) and non-nucleolus-forming 5S (minor) rDNAs, were physically mapped using fluorescence in situ hybridization (FISH) and primed in situ labelling. The minor rDNA locus was located on the subtelo-acrocentric chromosome pair No. 9, whereas the major rDNA loci were dispersed on 14 chromosome pairs, showing a considerable inter-individual variation in the number and location. The major and minor rDNA loci were located at different chromosomes. Multichromosomal location (3-6 sites) of the NORs was demonstrated by silver nitrate (AgNO3) impregnation. All Ag-positive i.e. active NORs corresponded to the GC-rich blocks of heterochromatin.