Delineación epidemiológica y fenotípica de la distrofia miotónica de Steinert / Epidemiologic and phenotypic delineation of Steinert's myotonic dystrophy

RESUMEN Introducción: la distrofia miotónica de Steinert es una enfermedad neuromuscular hereditaria, cuya prevalencia global es 1/8000. Tiene expresividad clínica muy variable. Objetivo: delinear las características epidemiológicas y fenotípicas en la distrofia miotónica de Steinert. Métodos: se realizó una investigación descriptiva, en Pinar del Río, desde el mes de enero del año 2019 hasta marzo del 2021. Se buscaron en bases de datos de Genética Clínica, los individuos con diagnóstico confirmado, y a partir de estos se confeccionaron las genealogías. Se realizó una pesquisa clínica activa para todos los miembros consanguíneos. Se usaron como instrumentos, la historia clínica genética y una planilla con datos del examen clínico. Resultados: el 79,3 % de los casos se diagnosticaron después del estudio de las genealogías, en estas fueron identificadas 11 familias con 87 miembros. Se registró prevalencias de 6 y 4,1 x 10 000 habitantes en los municipios Minas de Matahambre y Viñales respectivamente, según el lugar natural de las personas, las cuales disminuyeron con la migración hacia el municipio Pinar del Río. Existe una correlación entre la edad de inicio y la del diagnóstico de la enfermedad. Entre las formas clínicas y el tipo de herencia no se encontraron diferencias significativas X2= 12,58 p=0,127220653. Fenotípicamente la ptosis palpebral y la debilidad muscular están presentes en el 89,6 % y el 82,7 %. Conclusiones: la delineación epidemiológica y fenotípica, mediante la pesquisa activa en las familias, permite el seguimiento y conductas individualizadas que redundan en mayor satisfacción y calidad de vida.

ABSTRACT Introduction: Steinert's myotonic dystrophy is a neuromuscular hereditary disease, which global prevalence is 1/8000. It has a very variable clinical expression. Objective: to delineate the epidemiologic and phenotypic characteristics of Steinert's myotonic dystrophy. Methods: a descriptive research was conducted in Pinar del Rio from January 2019 to March 2021. The databases of Clinical Genetics were reviewed, making the genealogies of the individuals with a confirmed diagnosis; an active clinical survey was carried out for all of the blood relative members. Clinical-genetic history and a form including the data of the clinical examination were used as instruments. Results: the 79,3 % of the cases were diagnosed after the study of their genealogies, where 11 families with 87 members were identified. The prevalence reached 6 and 4,1 x 10 000 inhabitants in Minas de Matahambre and Viñales municipalities respectively and according to the place of birth of these individuals, which have decreased due to the immigration to Pinar del Rio municipality. Between the clinical forms and the type of inheritance, no significant differences were found X2= 12,58 p=0,127220653. Palpebral ptosis and muscular weakness are phenotypically present in 89,6 % and 82,7 % of the individuals. Conclusions: the epidemiologic and phenotypic delineation during the active survey in families allows carrying out the follow-up and to establish individualized actions which will result in greater satisfaction and quality of life.

Relationship between PERK pathway-mediated endoplasmic reticulum stress and reduction of cerebral ischemia-reperfusion injury by dexmedetomidine in mice / 中华麻醉学杂志

Objective:To evaluate the relationship between protein kinase RNA-like endoplasmic reticulum kinase (PERK) pathway-mediated endoplasmic reticulum stress and the reduction of cerebral ischemia-reperfusion (I/R) injury by dexmedetomidine in mice by the in vivo experiment and the cell experiment. Methods:In the in vivo experiment, 20 healthy clean-grade male mice, aged 6-8 weeks, weighing 20-30 g, were divided into 4 groups ( n=5 each) using a random number table method: sham operation group (group S), sham operation+ dexmedetomidine group (group SD), cerebral I/R group (group IR) and cerebral I/R+ dexmedetomidine group (group IRD). Cerebral I/R was established by two-vessel occlusion plus hypotension.Dexmedetomidine 25 μg/kg was intraperitoneally injected at 10 min of ischemia in group IRD and at the corresponding time point in group SD.Neurological function was assessed using modified neurological severity score at 1 h of reperfusion.The animals were then sacrificed and brain tissues were taken for determination of the expression of endoplasmic reticulum stress-related proteins such as immunoglobulin heavy chain-binding protein (BIP), eukaryotic translation initiation factor 2α (EIF-2α), phosphorylated EIF-2α (p-EIF-2α), PERK and phosphorylated PERK (p-PERK) (by Wester blot). In the cell experiment, a mouse hippocampal neuronal cell line was selected and divided into 4 groups ( n=12 each) using a random number table method: control group (group C), oxygen-glucose deprivation/restoration (OGD/R) group (group OGD/R), OGD/R+ dexmedetomidine group (group OGD/R+ D) and OGD/R+ ISRIB (PERK pathway inhibitor) group (group OGD/R+ ISRIB). Cells were exposed to 94%N 2-5%CO 2-1%O 2 and incubated in a low-glucose DMEM medium for 6 h followed by restoration to establish OGD/R model.At 30 min before OGD, dexmedetomidine (final concentration 5 mmol/L) was added in group OGD/R+ D, and ISRIB (final concentration 10 mmol/L) was added in group OGD/R+ ISRIB.After 12-h restoration was completed, the cell survival rate was detected by CCK-8 assay.At 24 of restoration, the expression of endoplasmic reticulum stress-related proteins was determined by Wester blot. Results:In the in vivo experiment, compared with group S, neurobehavioral score was significantly increased and the expression of BIP, p-EIF-2α and p-PERK in brain tissues was up-regulated in group IR ( P<0.05). Compared with group IR, neurobehavioral score was significantly decreased and the expression of BIP, p-EIF-2α and p-PERK in brain tissues was down-regulated in group IRD ( P<0.05). In the cell experiment, compared with group C, the expression of BIP, p-EIF-2α, PERK and p-PERK was significantly up-regulated, and the cell survival rate was decreased in group OGD/R ( P<0.05). Compared with group OGD/R, the expression of BIP, p-EIF-2α, PERK and p-PERK was significantly down-regulated, and the cell survival rate was increased in OGD/R+ D, OGD/R+ ISRIB groups ( P<0.05). Compared with group OGD/R+ ISRIB, the expression of PERK was significantly down-regulated ( P<0.05) and no significant change was found in the other parameters in group OGD/R+ D ( P>0.05). Conclusion:The mechanism by which dexmedetomidine reduces cerebral I/R injury may be related to inhibiting PERK pathway-mediated endoplasmic reticulum stress in mice.

Expression and Phosphorylation of PKR and NF-κB p65 in Cervical Lesions / 天津医药

Objective To identify the significance of expression and phosphorylation of protein kinase R(PKR) and nuclear factor NF-κB p65 in cervical lesions, and the effect of high-risk human papilloma virus(hsHPV) on expression and phosphorylation of R(PKR) and NF-κB p65. Methods A total of 67 patients with cervical cancer, 149 patients with cervi-cal intraepithelial neoplasia (CINⅠ-Ⅲ) and 15 normal control were included in this study. The expression levels of PKR, phosphorylated PKR (p-PKR), NF-κB p65 and phosphorylated NF-κB p65 (p-NF-κB p65) were detected by immunohisto-chemical SP method in three groups. Results The positive expression rates of PKR and p-PKR in cytoplasm were signifi-cantly lower in hsHPV positive group than those in hsHPV negative group (27.2% and 11.0% vs 41.1% and 21.1%,χ2 =4.858 and 4.371,P＜0.05). The positive expression rates of NF-κB p65 and p-NF-κB p65 in cytoplasm and nucleus were significantly higher in hsHPV positive group than those in hsHPV negative group (46.3%, 25.7%, 22.8% and 12.5% vs 32.6%, 14.7%, 11.6%and 4.2%,χ2=4.345,4.048,4.729 and 4.650 respectively,P＜0.05). The positive expression rates of PKR in kytoplasm and karyon were significantly lower in NF-κB p65 (+) group than those in NF-κB p65 (-) group (25.5%vs 38.0%and 20.4%vs 36.3%,χ2=3.898 and 4.396 respectively, P＜0.05). The positive expression rate of PKR in kyto-plasm was significantly lower in p-NF-κB p65 (+) group than those in p-NF-κB p65 (-) group (19.0%vs 36.0%,χ2=4.462, P＜0.05). Conclusion hsHPV may inhibit the expression and phosphorylation of PKR but promote the expression and phosphorylation of NF-κB p65. The expression and phosphorylation of NF-κB p65 may inhibit the expression of PKR. Regu-lating effects of three may be associated with the generation and progression of cervical cancer.

Changes of protein kinase-like endoplasmic reficulum kinase and glucose-regulated protein 78 expression in rats after focal ischemic preconditioning / 中华神经科杂志

ObjectiveTo investigate the effect of focal ischemic preconditioning (IPC) on the expression of protein kinase-like endoplasmic reticulum kinase ( PERK ) and glucose-regulated protein 78 (GRP78) mRNA and protein after focal cerebral ischemia/reperfusion (I/R) in rats.MethodsAll 120 male SD rats were randomly divided into three groups: sham-operation group,middle cerebral artery occlusion (MCAO) group and brain ischemia preconditioning (BIP) group.Each group was further divided into 4 subgroups according to 12 h,1,2 and 3 d after I/R.The IPC models were made in order to measure the expression of PERK,GRP78 mRNA and protein by in situ hybridization and Western blot,and the apoptosis rate of neuron by flow cytometry. Results ①The expression of PERK mRNA increased and reached the peak at 12 h,then decreased continuously after 1 d.BIP could decrease its expression.The expression of PERK protein increased at 12 h and reached the peak at 24 h,then decreased continuously after 2 d.BIP could decrease its expression.②The expression both of GRP78 mRNA and its protein all increased and reached the peak at 12 h,then decreased continuously.BIP could increase their expression (mRNA:12 h: 136.70±9.53,F=32.265; 24 h:147.54 ±9.97,F=54.920; 2 d:158.16 ±9.44,F=45.374; 3d: 165.85±10.26,F=16.493,P＜0.05; protein:12 h: 1.319±0.116,F=5.619,P＜0.05; 24 h: 1.226±0.108,F=33.742,P＜0.01; 2 d:1.183 ±0.112,F =46.556,P ＜0.01; 3 d:1.115± 0.098,F =11.730,P＜0.05).③The rate of apoptosis neuron of rats in MCAO increased markedly at 12 h after reperfusion,and reached the peak at 1 d,then decreased continuously.BIP could decrease the rate of apoptosis neuron. Conclusion BIP can protect neurons through inhibiting the expression of PERK and inducing the expression of GRP78 after endoplasmic reticulum stress in rats.

Hsp90 mediates activation of the heme regulated eIF-2 kinase during oxidative stress.

The heme-regulated inhibitor (HRI), a member of the eIF-2 kinase family is crucial for regulating protein synthesis during stress. In addition to heme, stress proteins Hsp90 and Hsp70 are known to regulate HRI. The present study aims to determine the physical association of these Hsps in the regulation of HRI activation during oxidative stress using human K562 cells as a model. Extracts from the stress-induced cells were used for determining HRI kinase activity by measuring eIF-2 phosphorylation, and Hsp-HRI interaction by immunoprecipitation and immunoblot analyses. The results indicate a significant increase in both Hsp70 and Hsp90 expression during AAPH (2, 2’-azobis (2-amidinopropane) dihydrochloride)-induced oxidative stress. Further, their interaction with HRI, which correlates well with its increased HRI kinase activity leads to inhibition of protein synthesis. Thus, we demonstrate that Hsps play an important role in the regulation of initiation of protein synthesis during oxidative stress.

Expression of phosphatidylinositol 3-kinase/protein kinase B signaling pathway in cervical cancer and clinical significance / 中国医师进修杂志

Objective To determine the expression of phosphatidyhnositol 3-kinase (PI3K), phosphorylated protein kinase B (P-AKT) and protein kinase B (AKT) in cervical cancer and explore the correlations with the genesis and development of cervical cancer. Methods Western blot was used to detect the expression of PI3K, P-AKT and AKT proteins in 66 cases of cervical tissues, including 33 cervical cancers, 23 cervical intraepithelial cancer, 10 normal cervical tissues, and analyzed the clinical significances according to clinical informations. Results In cervical cancers, cervical intraepithelial cancer and normal cervical tissues, the expression of PI3K protein were 1.3880±0.0435, 0.5330±0.0939, 0.2427±0.0888 and had significant differences among them, but there was no significant difference in the ratio of P-AKT and AKT, which were 5.8702±0.0543, 5.0755±0.0888, 3.8353±0.0056. The ratios of P-AKT and AKT had association with histological type, the ratios in squamous cancer of the cervix and in adenocancer and denosquamous cancer were 6.7823±0.7745 and 0.7621±0.0709, and the ratios were much higher in squamous cancer of the cervix than adenocancer and denosquamous cancer. Conclusions Overexpression of PI3K protein is involved in the occurrence of human cervical cancer. The ratio of P-AKT and AKT plays a more important role in squamous cancer of the cervix.

Expression of Double-stranded RNA-dependent Protein Kinase in Malignant Melanoma and Ordinary Nevi / 中华皮肤科杂志

Objective To study the expression of double-stranded RNA-dependent protein kinase (PKR) in malignant melanoma and ordinary nevi. Methods The expression of PKR and proliferating cell nuclear antigen was examined in 42 cases of malignant melanoma and 25 ordinary nevi by an immunohistochemical method. Results The positive rate of PKR expression was higher in the patients with malignant melanoma than that in the patients with ordinary nevi (P