川芎嗪诱导大鼠骨髓间质干细胞分化为神经元样细胞的研究

目的用川芎嗪(ligustrazin hydrochloride)在体外定向诱导SD青年鼠骨髓间质干细胞(mesenchymal stem cells，rMSCs)分化为神经元样细胞。方法用低糖DMEM冲洗骨髓腔，收集骨髓细胞悬液，接种在塑料培养瓶中。经体外扩增、纯化，选用第5代后的骨髓间质干细胞进行诱导分化。用10μg／LbFcF预诱导24h，更换成含川芎嗪的无血清培养基DMEM诱导间质干细胞分化为神经元样细胞。用免疫组织化学SABC法鉴定神经丝蛋白(NF—M)、神经元特异性烯醇化酶(NSE)、巢蛋白(nestin)、微管联合蛋白-2(MAP-2)、生长相关蛋白-43(GAP-43)、胶质纤维酸性蛋白(GFAP)的表达。结果第5代间质干细胞形态达到均一，呈梭形。用川芎嗪诱导15min到3h，间质干细胞胞体逐渐增大，并伸出细长突起形似神经元样细胞。免疫组织化学显示NF-M、NSE、nestin、MAP-2和GAP-43表达阳性，而GFAP阴性。对照组上述染色均为阴性。结论川芎嗪可诱导骨髓间质干细胞分化为神经元样细胞。     

A novel autosomal recessive non-syndromic deafness locus (DFNB35) maps to 14q24.1-14q24.3 in large consanguineous kindred from Pakistan

Autosomal recessive nonsyndromic deafness is one of the most frequent forms of inherited hearing impairment. Over 30 autosomal recessive nonsyndromic hearing loss loci have been mapped, and 15 genes have been isolated. Of the over 30 reported autosomal recessive nonsyndromic hearing loss (NSHL) loci, the typical phenotype is prelingual non-progressive severe to profound hearing loss with the exception of DFNB8, which displays postlingual onset and DFNB13, which is progressive. In this report we describe a large inbred kindred from a remote area of Pakistan, comprising six generations and segregating autosomal recessive nonsyndromic prelingual deafness. DNA samples from 24 individuals were used for genome wide screen and fine mapping. Linkage analysis indicates that in this family the NSHL locus, (DFNB35) maps to a 17.54 cM region on chromosome 14 flanked by markers D14S57 and D14S59. Examination of haplotypes reveals a region that is homozygous for 11.75 cM spanning between markers D14S588 and D14S59. A maximum two-point LOD score of 5.3 and multipoint LOD score of 7.6 was obtained at marker D14S53. The interval for DFNB35 does not overlap with the regions for DFNA9, DFNA23 or DFNB5.     

Expression of keratin K2e in cutaneous and oral lesions: association with keratinocyte activation,proliferation, and keratinization

The cytoskeleton in keratinocytes is a complex of highly homologous structural proteins derived from two families of type I and type II polypeptides. Keratin K2e is a type II polypeptide that is expressed in epidermis late in differentiation. Here we report the influence of keratinocyte activation, proliferation, and keratinization on K2e expression in samples of cutaneous and oral lesions. The normal expression of K2e in the upper spinous and granular layers of interfollicular epidermis is increased in keloid scars but showed distinct down-regulation in psoriasis and hypertrophic scars where keratinocytes are known to undergo activation. Unlike normal and psoriatic skin, K2e expression in hypertrophic and keloid scars began in the deepest suprabasal layer. In cutaneous basal and squamous cell carcinomas, K2e was absent in most tumor islands but the overlying epidermis showed strong expression. No significant K2e expression in nonkeratinized or keratinized oral epithelia, including buccal mucosa, lateral border of tongue and gingiva was detected. In oral lichen planus K2e expression was undetectable, but in benign keratoses of lingual mucosa induction of K2e along with K1 and K10 was observed. In mild-to-moderate oral dysplasia with orthokeratinization, K2e was highly expressed compared with parakeratinized areas but in severe dysplasia as well as in oral squamous cell carcinoma, K2e expression was undetectable. Taken together, the data suggest that K2e expression in skin is sensitive to keratinocyte activation but its up-regulation in oral lesions is a reflection of the degree of orthokeratinization.     

Pemphigus Vulgaris Autoantibody Response is Linked to HLA-DQB10503 in Pakistani Patients

ABSTRACT: Pemphigus vulgaris (PV) is an autoimmune disease of the skin and mucous membranes characterized by an autoantibody response against an epidermal cadherin. We performed high resolution HLA class II typing in 19 patients with PV from Rawalpindi, Pakistan and 19 non-Jewish European PV patients from Boston by sequence-specific oligonucleotide probe hybridization. The results were compared with two separate ethnically matched control populations. We found that PV patients from Pakistan had significantly increased frequencies of DRB1*1404 ( p = 0.01), DQA1*0101 ( p = 0.02), and DQB1*0503 ( p = 0.01). Among the patients of non-Jewish European ancestry, DRB1*1401 ( p < 10⁻⁶), DQA1*0101 ( p < 10⁻⁵) and DQB1*0503 ( p < 10⁻⁶), were increased in PV patients. Formal linkage analysis between the major histocompatibility complex and the PV antibody was performed in 67 relatives of the 19 Pakistani patients. The results showed strong evidence for linkage of HLA-DRB1*1404, DQA1*0101, DQB1*0503, with the presence of PV antibody in relatives’ families with a significant logarithm of the odds score of 6.06. Based on the three dimensional structure of class II molecules, we propose that HLA-DQA1*0101 and DQB1*0503, encode a negatively charged P9 peptide binding pocket of the DQ molecule and are significantly associated with susceptibility to PV in non-Jewish populations.     

Teebi hypertelorism syndrome: report of a family with previously unrecognized findings

We present a family consisting of a mother, a daughter, and a son with Teebi hypertelorism syndrome, including some previously unrecognized manifestations. The clinical findings include a prominent forehead, arched eyebrows, pronounced hypertelorism, long philtrum, mild interdigital webbing, fifth-finger clinodactyly, umbilical anomalies, and hypotonia. The mother and daughter also had ptosis requiring surgical correction. The daughter has bilateral iridochorioretinal colobomas with high hyperopia and a small umbilical hernia. The son has less striking facial features but was born with a small omphalocele, large ASD secundum, PDA, bilateral cryptorchidism right hydronephrosis, and a cystic left kidney. The mother had an umbilical hernia requiring surgical correction as a child and a history of heart murmur. Both children have normal hearing and mild developmental delay. Their high-resolution karyotypes were normal and the FISH for 22q11 microdeletion was negative in the daughter. We conclude that cardiac defects in Teebi hypertelorism syndrome are not rare findings and that eye colobomas and renal anomalies were previously unrecognized.     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.      

A C-Terminal Hydrophobic Region is Required for Homo-Oligomerization of the Hepatitis E Virus Capsid (ORF2) Protein

Hepatitis E virus (HEV) is the causative agent of hepatitis E, anacute form of viral hepatitis. The open reading frame 2 (ORF2) of HEV encodes the viral capsid protein, which can self-oligomerize into virus-like particles. To understand the domains within this protein important for capsid biogenesis, we have carried out in vitro analyses of association and folding patterns of wild type and mutant ORF2 proteins. When expressed in vitro or in transfected cells, the ORF2protein assembled as dimers, trimers and higher order forms. WhileN-terminal deletions up to 111 amino acids had no effect, the deletion of amino acids 585–610 led to reduced homo-oligomerization. This deletion also resulted in aberrant folding of the protein, as determined by its sensitivity to trypsin. This study suggests that a C-terminal hydrophobic region encompassing amino acids 585–610 of the ORF2 protein might be critical for capsid biogenesis.     

Patients with suspected myocardial infarction: effect of mode of referral on admission time to a coronary care unit.

The aim of this prospective study was to determine the delay between the onset of symptoms and arrival in the coronary care unit of patients with suspected acute myocardial infarction, and the relative contribution to the total delay of patient delay, method of referral (self referral or general practitioner referral) and delay in the hospital before reaching the coronary care unit. All patients admitted with chest pain to the coronary care unit at Dudley Road Hospital, Birmingham, over the six month period April-September 1989 were included in the study. Ninety five patients were referred by their general practitioner and 107 patients attended the accident and emergency department directly or arrived by ambulance without contacting their general practitioner. The proportion of self referred and general practitioner referred patients with acute myocardial infarction, angina and non-cardiac chest pain were not significantly different. The total delay was significantly longer for patients who had been referred by their general practitioner (median 5.3 hours) than for self referrals (3.2 hours, P less than 0.001), with a significantly higher proportion of self referrals arriving at the coronary care unit within six hours of the onset of symptoms (77% versus 54%, P less than 0.01). Among general practitioner referrals, initial patient delay accounted for a median of 2.5 hours and the general practitioner's response time for a median of 1.1 hours. The delay in hospital was similar for both groups of patients. In inner city areas, self referral may result in considerably less delay than general practitioner referral allowing a greater proportion of patients to receive effective thrombolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)