Frequency of SCA1, SCA2, SCA3/MJD, SCA6, SCA7, and DRPLA CAG trinucleotide repeat expansion in patients with hereditary spinocerebellar ataxia from Chinese kindreds

OBJECTIVE

To assess the frequency of SCA1 (spinocerebellar ataxia type 1), SCA2, SCA3/MJD (spinocerebellar ataxia type 3/Machado-Joseph disease), SCA6, SCA7, and DRPLA (dentatorubropallidoluysian atrophy) CAG trinucleotide repeat expansions [(CAG)n] among persons diagnosed with hereditary SCA from Chinese families.

PATIENTS AND METHODS

Spinocerebellar ataxia type 1, SCA2, SCA3/MJD, SCA6, SCA7, and DRPLA (CAG)n mutation were detected with the polymerase chain reaction, highly denaturing polyacrylamide gel electrophoresis, and silver staining technique in 167 patients with autosomal dominant SCA from 85 Chinese families and 37 patients with sporadic SCA.

RESULTS

Spinocerebellar ataxia type 1 (CAG)n mutation in 7 patients from 4 kindreds (4.70%) was expanded to 53 to 62 repeats. Spinocerebellar ataxia type 2 (CAG)n mutation in 12 patients from 5 kindreds (5.88%) was expanded to 42 to 47 repeats. Spinocerebellar ataxia type 3/Machado-Joseph disease (CAG)n mutation in 83 patients from 41 kindreds (48.23%) was expanded to 68 to 83 repeats. Sixty-five patients from 35 kindreds (41.19%) and 37 patients with sporadic SCA did not test positive for SCA1, SCA2, SCA3/MJD, SCA6, SCA7, or DRPLA. There was a predictable inverse relationship between the number of CAG repeats and the age at onset for SCA3/MJD and SCA2. Clinically, dementia and hyporeflexia were more frequent in patients with SCA2, while spasticity, hyperreflexia, and Babinski signs were more frequent in patients with SCA3/ MJD, and those might be helpful in clinical work to primarily distinguish patients with SCA3/MJD and SCA2 from others with different types of SCA.

CONCLUSIONS

The frequency of SCA3/MJD is substantially higher than that of SCA1 and SCA2 in patients with autosomal dominant SCA from Chinese kindreds, who are non-Portuguese. Clinical expressions of the various types of SCAs overlap one another; therefore, for clinical study it is important to make a gene diagnosis and genetic classification for patients with SCA.

Sorption and diffusion behavior of Cs and Sr on Jih-Hsing bentonite

Sorption and diffusion are important processes for the transport of radionuclides through buffer materials such as bentonite. In this study, the sorption and diffusion behaviors of Cs and Sr on Jih-Hsing bentonite are investigated using batch and through-diffusion techniques. The distribution coefficients (Kds) of Cs and Sr from batch experiments are approximately 1200 ml/g and 800 ml/g, respectively. It is found that the Freundlich isotherm model could fit the sorption isotherm with an equilibrium concentration of 10(-7)-10(-1) N. The calculated retardation factors (Rds) for samples at densities of 1.8 g/cm3, 2.0 g/cm3 and 2.2 g/cm3 are 5685, 7744, and 11000 for Cs, and are 3790, 5162, and 7334 for Sr. For the through-diffusion experiments on the compacted samples with the same densities, the corresponding apparent diffusion coefficients for Cs are (2.83+/-0.75) x 10(-13) m2/s, (1.97+/-0.02) x 10(-13) m2/s, and (1.91+/-0.12) x 10(-13) m2/s, respectively. The corresponding apparent diffusion coefficients for Sr are (1.33+/-0.13) x 10(-13) m2/s, (1.51+/-0.15) x 10(-13) m2/s, and (1.34+/-0.10) x 10(-13) m2/s. The Rds obtained from the diffusion experiments for sample densities of 1.8 g/cm3, 2.0 g/cm3 and 2.2 g/cm3 are 1166+/-355, 2113+/-123, 2796+/-171 for Cs, and 713+/-258, 510+/-68, 846+/-158 for Sr. It appears that the retardation factors obtained from the diffusion experiments are about one order of magnitude lower than those derived from the batch experiments. The discrepancy and the possible explanations are discussed in the paper.

Liver injury in COVID-19: clinical features and treatment management

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has spread to many countries around the world. In addition to lung disease, severe cases also displayed varying degrees of liver injury. This article will describe the latest developments regarding coronavirus and the pathogenesis of liver injury, the prone population and clinical characteristics of these patients, as well as providing some suggestions for clinical treatment.

Genome sequencing of a 239-kb region of rice chromosome 10L reveals a high frequency of gene duplication and a large chloroplast DNA insertion

In this study we describe a 239-kb region on the long arm of rice chromosome 10 that contains a high density (71%) of locally duplicated genes, including 24 copies of a glutathione S-transferase gene. Intriguingly, embedded within this cluster is a large insertion (approximately 33 kb) of rice (Oryza sativa) chloroplast DNA that is derived from two separate regions of the chloroplast genome. We used DNA fiber-based fluorescence in situ hybridization (fiber-FISH) analyses of O. sativa spp. japonica nuclei to confirm that the insertion of organellar DNA was not a cloning artifact. The sequence of the chloroplast insertion is nearly identical (99.7% identity) to the corresponding regions in the published rice chloroplast genome sequence, suggesting that the transfer event occurred recently. PCR amplification and sequence analysis in two subspecies of rice, O. sativa spp. japonica and spp. indica, indicates that the transfer event predated the divergence of these two subspecies. The chloroplast insertion is flanked by a 2.1-kb perfect direct repeat that is unique to this location in the rice genome.

Involvement of cell adhesion molecules in polydatin protection of brain tissues from ischemia-reperfusion injury

Previous studies have demonstrated that polydatin, a crystal component extracted from the root stem of the perennial herbage Polygonum Cuspidatum Sieb.et Zucc, exerts a neuroprotective effect on cerebral injury induced by ischemia/reperfusion. To investigate the possible mechanism of this action, we determined the effects of polydatin on the expression of cell adhesion molecules (CAMs) after ischemia-induced cerebral injury. Rats were treated with polydatin (i.v.) immediately after the operation of middle cerebral artery occlusion (MCAO) for 1 h. It was found that polydatin improved neurological deficits and reduced the volume of brain infarction. In addition, polydatin decreased the levels of CAMs relative to the control (MCAO alone); these included intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, L-selectin and Integrins. These results suggest that polydatin exerts protective effects likely via inhibition of the expression of various CAMs; polydatin may be a potential agent for treatment of brain injury associated with stroke.

Gene expression profiling in human fetal liver and identification of tissue- and developmental-stage-specific genes through compiled expression profiles and efficient cloning of full-length cDNAs

Fetal liver intriguingly consists of hepatic parenchymal cells and hematopoietic stem/progenitor cells. Human fetal liver aged 22 wk of gestation (HFL22w) corresponds to the turning point between immigration and emigration of the hematopoietic system. To gain further molecular insight into its developmental and functional characteristics, HFL22w was studied by generating expressed sequence tags (ESTs) and by analyzing the compiled expression profiles of liver at different developmental stages. A total of 13,077 ESTs were sequenced from a 3'-directed cDNA library of HFL22w, and classified as follows: 5819 (44.5%) matched to known genes; 5460 (41.8%) exhibited no significant homology to known genes; and the remaining 1798 (13.7%) were genomic sequences of unknown function, mitochondrial genomic sequences, or repetitive sequences. Integration of ESTs of known human genes generated a profile including 1660 genes that could be divided into 15 gene categories according to their functions. Genes related to general housekeeping, ESTs associated with hematopoiesis, and liver-specific genes were highly expressed. Genes for signal transduction and those associated with diseases, abnormalities, or transcription regulation were also noticeably active. By comparing the expression profiles, we identified six gene groups that were associated with different developmental stages of human fetal liver, tumorigenesis, different physiological functions of Itoh cells against the other types of hepatic cells, and fetal hematopoiesis. The gene expression profile therefore reflected the unique functional characteristics of HFL22w remarkably. Meanwhile, 110 full-length cDNAs of novel genes were cloned and sequenced. These novel genes might contribute to our understanding of the unique functional characteristics of the human fetal liver at 22 wk.

Detection of gastric slow wave propagation from the cutaneous electrogastrogram

The gastric slow wave is originated in the proximal stomach and propagates distally toward the pylorus. It determines the maximum frequency and propagation of gastric contractions. The aim of this study was to detect the propagation of the gastric slow wave from the surface electrogastrogram (EGG). The study was performed in 11 healthy subjects of normal weight. Gastric myoelectrical activity was recorded for 1 h in the fasting state with the use of a specially designed multichannel recording device that was composed of four identical amplifiers with cutoff frequencies of 1.8 and 16.0 cycles/min. Four active electrodes were placed on the abdomen along the gastric axis and were connected to a common reference electrode placed near the xiphoid process, yielding four-channel bipolar EGG signals. Cross-covariance analysis was performed to compute the time lag among the four channels. There was a time lag in EGG waveform between channels 1 and 4 (9.6 +/- 1.1 s); the average time during which the time lag was observed (>/=3 s) was 89.9 +/- 9.0%. There was a significant difference in the time lag among different adjacent channels (P < 0.04); the time lag observed between channels 3 and 4 was significantly smaller than that between channels 1 and 2 (P < 0.03). No correlation was found between the body mass index and the time lag between channels 1 and 4 (r = -0.31, P = 0.3). It was concluded that, with a multichannel recording device with identical multiamplifiers and an appropriate arrangement of abdominal electrodes, the propagation of the gastric slow wave could be identified from the EGG in healthy subjects. This method may be used to detect the coupling of the gastric slow wave noninvasively.

Pregnancy and COVID-19: management and challenges

The consequences of COVID-19 infecting pregnant women and the potential risks of vertical transmission have become a major issue. Since little is currently known about COVID-19 in pregnancy, the understanding of COVID-19 in this particular group will be updated in time, and a comprehensive review will be useful to evaluate the impact of COVID-19 in pregnancy. Based on recently published literature and official documents, this review provides an introduction to the pathogenesis, pathology, and clinical features of COVID-19 and has focused on the current researches on clinical features, pregnancy outcomes and placental histopathological analysis from pregnant women infected with SARS-CoV-2 in comparison with SARS-CoV and MERS-CoV. These viruses trigger a cytokine storm in the body, produce a series of immune responses, and cause changes in peripheral leukocytes and immune system cells leading to pregnancy complications that may be associated with viral infections. The expression of ACE2 receptors in the vascular endothelium may explain the histological changes of placentas from pregnant women infected by SARS-CoV-2. Pregnant women with COVID-19 pneumonia show similar clinical characteristics compared with non-pregnant counterparts. Although there is no unequivocal evidence to support the fetal infection by intrauterine vertical transmission of SARS, MERS and SARS-CoV-2 so far, more and more articles began to report maternal deaths due to COVID-19. In particular, from February 26, 2020 (date of the first COVID-19 case reported in Brazil) until June 18, 2020, Brazil reported 124 maternal deaths. Therefore, pregnant women and neonates require special attention regarding the prevention, diagnosis and management of COVID-19.

Promoter analysis of the cap8 operon, involved in type 8 capsular polysaccharide production in Staphylococcus aureus

The production of type 8 capsular polysaccharide (CP8) in Staphylococcus aureus is regulated in response to a variety of environmental factors. The cap8 genes required for the CP8 production in strain Becker are transcribed as a single large transcript by a primary promoter located within a 0.45-kb region upstream of the first gene of the cap8 gene cluster. In this study, we analyzed the primary cap8 promoter region in detail. We determined the transcription initiation site of the primary transcript by primer extension and identified the potential promoter sequences. We found several inverted and direct repeats upstream of the promoter. Deletion analysis and site-directed mutagenesis showed that a 10-bp inverted repeat of one of the repeats was required for promoter activity. We showed that the distance but not the specific sequences between the inverted repeat and the promoter was critical to the promoter activity. However, insertion of a DNA sequence with two or four helix turns in this intervening region had a slight effect on promoter activity. To demonstrate the biological significance of the 10-bp inverted repeat, we constructed a strain with a mutation in the repeat in the S. aureus Becker chromosome and showed that the repeat affected CP8 production mostly at the transcriptional level. By gel mobility shift assay, we demonstrated that strain Becker produced at least one protein capable of specific binding to the 10-bp inverted repeat, indicating that the repeat serves as a positive regulatory protein binding site. In addition, reporter gene fusion analysis showed that the cap8 promoter activity was influenced by various growth media and affected most by yeast extract. Our results suggest that yeast extract may exert its profound inhibitory effect on cap8 gene expression through the 10-bp inverted repeat element.

Selective determination of a group of organic compounds in complex sample matrixes by LC/MIMS with on-line immunoaffinity extraction

An on-line immunoaffinity extraction with liquid chromatography/membrane introduction mass spectrometry (IAE/LC/MIMS) method for the determination of BTEX compounds in complex sample matrixes is described. This method uses an immunoaffinity column (1 mm i.d. x 20 mm) for on-line sample cleanup and enrichment, a 5-micron C18 trapping column (2 mm i.d. x 20 mm) for analyte focusing, a 3-micron C18 analytical column (3.2 mm i.d. x 100 mm) for separation, and a membrane introduction mass spectrometer for quantitation. The immunoaffinity column was evaluated in terms of binding capacity, recovery, and enrichment factor. The method was optimized for the determination of BTEX compounds in a mixture of 30 volatile organic compounds, which showed no matrix interference and a dramatic improvement of the detection limit over that of the LC/MIMS method (up to 474-fold). This method was also used for the determination of BTEX compounds in several gasoline-contaminated water samples, and the results were compared with the EPA reference methods.

Rhythmic expression of Fos-related proteins within the rat suprachiasmatic nucleus during constant retinal illumination

Within the retinorecipient or ventrolateral subfield of suprachiasmatic nuclei (SCN) in rodents, expression of the protein product of the c-fos proto-oncogene, Fos, is regulated by light. In the present study, the expression of Fos and Fos-related proteins within the SCN was examined immunocytochemically for evidence of rhythmic variation in rats sacrificed at different circadian times during exposure to constant retinal illumination (LL). In all animals, nuclear Fos immunoreactivity was mainly confined to an area of the SCN that was coextensive with neuropeptide Y-immunopositive fibers distinguishing the ventrolateral subfield of the nucleus. Moreover, Fos-immunostaining within the ventrolateral SCN of rats exposed to LL fluctuated over the course of the circadian cycle, such that the density of immunopositive cells within this subfield was 2 times greater during the subjective night than during the subjective day. Since Fos expression within the SCN oscillates in the absence of photoperiodic time cues and since the peak of this oscillation coincides with the circadian times when light modulates the periodicity of the SCN pacemaker, these data provide further evidence that expression of the c-fos gene may be a molecular signal in the circadian timekeeping mechanism in the SCN and its regulation by photic stimuli.

Transcriptional analysis of type 1 capsule genes in Staphylococcus aureus

Serotype 1 capsule of Staphylococcus aureus plays an important role in staphylococcal infections. A 14.6 kb chromosomal DNA fragment containing 13 cap1 genes responsible for the synthesis of type 1 capsule in S. aureus strain M has been previously cloned and sequenced in our laboratory. These genes are closely linked and are transcribed in one orientation. To study the transcription of these genes, we employed genetic complementation using a set of plasmids with various deletions in the 14.6 kb region to complement mutants mapped in each of the 13 genes. We found that there were six transcriptional units. By Northern hybridization using the entire gene cluster as a probe, we identified a large 14 kb band and several smaller bands ranging from 0.3 to 6 kb. The 14 kb band was also identified by various individual gene probes, suggesting that all 13 genes are transcribed into a large transcript. The 14 kb transcript and the smaller bands were not detected when a 533 bp fragment containing the potential promoter region upstream of the first gene (cap1A) was deleted from the chromosome, suggesting that the small transcripts are the degradation (processing) products of the 14 kb transcript. The activities of the promoters identified by genetic complementation tests were quantitatively measured by transcriptional fusions using xylE as the reporter gene. The result showed that the promoter preceding the first cap1 gene was 45-198-fold higher than the downstream promoters. The result from gene-fusion studies is in agreement with the Northern analysis in that only the transcript transcribed from the first promoter was detected. Taken together, these results suggest that the cap1 genes are organized as a large operon with at least five weak internal promoters, and the long polycistronic transcript is processed (degraded) into several smaller transcripts. The transcription initiation site of the primary transcript was mapped by S1 nuclease mapping and the major promoter was defined by deletion analysis of the promoter-xylE fusion. In addition, we showed that the internal promoters, despite their weak activities, were sufficiently effective at expressing their downstream genes required for producing capsule, compared to the wild-type strain.

Curcumin inhibits hypoxia inducible factor-1α-induced inflammation and apoptosis in macrophages through an ERK dependent pathway

OBJECTIVE

Atherosclerosis, a kind of peripheral arterial disease with chronic inflammation, leads to the dysfunction of the vascular system and many other diseases. Hypoxia has been proven to participate in the progression of atherosclerosis, while curcumin can inhibit hypoxia-inducible factor 1α (HIF-1α). However, the underlying mechanisms are still elusive.

PATIENTS AND METHODS

qRT-PCR was used to examine the expression of HIF-1α, IL-6 and TNFα of macrophages under hypoxic condition. Western blot was applied to examine the changes of HIF-1α, ERK and p-ERK after treatment with curcumin. Oli Red O staining and enzymatic assay were used to examine the lipid and total cholesterol in macrophages, respectively. ELISA was used to examine the release of IL-6 and TNFα by macrophages. FACS and MTT assays were applied to examine the apoptosis and proliferation of macrophages.

RESULTS

Here, we found curcumin inhibited the expression of HIF-1α at the protein level in macrophages under hypoxic condition and curcumin and HIF-1α inhibitors repressed the total cholesterol and lipid level in macrophage under hypoxic condition. Moreover, curcumin also decreased the expression of HIF-1α downstream genes, VEGF, HMOX1, ROS and PDGF. Then, the data show the HIF-1α-induced apoptosis and inflammation of macrophages were inhibited by curcumin. Curcumin also rescued the proliferation defect of macrophages caused by hypoxia. Furthermore, we found it inhibited the expression of HIF-1α via ERK signaling pathway.

CONCLUSIONS

We describe that curcumin inhibited the HIF-1α-induced apoptosis and inflammation of macrophages via ERK signaling pathways. These results suggest curcumin can be used for the treatment of atherosclerosis.

Diagnostic accuracy of LAMP assay for HBV infection

Background

Detection of hepatitis B virus (HBV) is vital for the diagnosis of hepatitis B infection. A novel test loop‐mediated isothermal amplification (LAMP) has been successfully applied to detect various pathogens. However, the accuracy of LAMP in diagnosing HBV remains unclear. Therefore, in the present study, the accuracy of LAMP for HBV detection was evaluated systematically.

Methods

Embase, Cochrane Library, and PubMed databases were searched for studies using LAMP to detect HBV. Then, two researchers extracted data and assessed the quality of literature using the QUADAS‐2 tool independently. I² statistic and chi‐square test were analyzed to investigate the heterogeneity, and Deek's funnel plot assessed the publication bias. The pooled sensitivity (SEN), specificity (SPE), positive LR (PLR), negative LR (NLR), diagnostic odds ratio (DOR), and 95% confidence intervals were displayed in forest plots. We calculated the area under the curve (AUC) to assess the overall efficiency of LAMP for HBV detection.

Results

A total of nine studies with 1298 samples were finally included in this evaluation. The pooled sensitivity and specificity of HBV detection were 0.91 (95% CI: 0.89 ~ 0.92) and 0.97 (95% CI: 0.94 ~ 0.99), respectively. The PLR, NLR, and DOR were 16.93 (95% CI: 6.15 ~ 46.55), 0.08 (95% CI: 0.05 ~ 0.14), and 397.57 (95% CI: 145.41 ~ 1087.07). Besides, the AUC was 0.9872, and Deek's plot suggested that there existed publication bias in the studies.

Conclusion

Compared with PCR, LAMP is a simple, rapid, and effective assay to diagnose HBV. However, additional evidence is essential to confirm that LAMP can replace other methods in diagnosing HBV infection.

Discovery and antibacterial study of potential PPK1 inhibitors against uropathogenic E. coli

Novel antibacterial agents are urgently needed to address the infections caused by multi-drug resistant bacteria. Urinary tract infections are common infectious diseases in clinical. Most of these infections are caused by drug-resistant uropathogenic Escherichia coli. PPK1 is an essential kinase for bacterial motility, biofilm formation, quorum sensing, and virulence factors in the expression of uropathogenic E. coli. In the present study, two small molecules potentially targeting PPK1 were discovered through virtual screening and biological assays. The in vitro and in vivo results suggested that the interaction of these compounds with PPK1 can disrupt biofilm formation of uropathogenic E. coli and reduce invasive ability and resistance to oxidative stress of this strain. Moreover, the compounds exhibit good antibacterial bacterial activity in the mice with urinary tract infection. Taken together, our findings could provide a new chemotype for the development of antibacterials targeting PPK1.

Endothelial progenitor cell miR-126 promotes homing of endothelial progenitor cells within arterial thrombus in patients with cerebral infarction and its molecular mechanism

OBJECTIVE

The present study was designed to investigate the effect of microRNA-126 (miR-126) on the migration and homing of endothelial progenitor cells (EPCs) within arterial thrombus of cerebral infarction patients.

MATERIALS AND METHODS

EPCs from rat bone marrow were isolated, and miR-126 overexpressed EPCs were constructed by lentiviral transfection. Then, the middle cerebral artery occlusion (MCAO) model was established by the method of thread ligation. Successfully established model rats were randomly divided into miR-126 overexpression EPC group, miR-126 wild type EPC group, and normal saline group. One day after the infarction, the miR-126 overexpression EPCs, miR-126 wild type EPCs, and normal saline, were injected into the lateral ventricle of the corresponding groups. Also, the transplanted cells were tracked by cell dye SPDiIC18. The expression of tight junction proteins ZO-1 and Claudin-5 in brain tissue was detected by Western blotting.

RESULTS

Transplanted cells were detected in the cerebral infarction area 3 days after transplantation by cell dye SP-DiIC18. The number of homing EPCs in miR-126 overexpression group was significantly higher than that of miR-126 wild type EPC group (p < 0.05). Also, the protein expression of ZO-1 and Claudin-5 in the miR- 126 overexpression EPC group was significantly higher compared with that of the miR-126 wild type EPC group and the normal saline group.

CONCLUSIONS

miR-126 overexpression EPCs, which were transplanted in the lateral ventricle, can home to the cerebral infarction areas via increasing increase.

Bapx1 mediates transforming growth factor-β- induced epithelial-mesenchymal transition and promotes a malignancy phenotype of gastric cancer cells

The homeoprotein Bapx1 is an important regulator of gastroduodenal tract morphogenesis. Here, we investigated how Bapx1 influences gastric cancer (GC) prognosis and elucidated the underlying mechanisms. Bapx1 expression was greater in GC tissues compared to adjacent non-tumor tissues and expression was positively correlated with mortality, lymph node and distance metastasis. Silencing Bapx1 diminished cell invasion/migration and decreased mesenchymal phenotypes. Transforming growth factor-β (TGF-β) induced Bapx1 expression and epithelial-mesenchymal transition (EMT) in GC cells. However, down-regulated Bapx1 reversed TGF-β induced invasion, migration, morphological changes, and EMT. In summary, Bapx1 indicates poor prognosis for GC by promoting tumor migration and invasion via TGF-β-induced EMT.