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61.
The newly identified human coronavirus was named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), based on a detailed analysis of clinical manifestation. It was reported that blood type O individuals were less likely to become infected by SARS-CoV, while blood type A individuals have an increased risk of severe illness. The Forssman antigen, or Forssman glycolipid synthase (FS), was first described in 1911 by John Frederick Forssman. Blood type A/B glycosyltransferases (AT/BTs) and Forssman glycolipid synthase (FS) are encoded by the evolutionarily related ABO (A/B alleles) and GBGT1 genes. In this article, based on published studies about the pathogenesis of the COVID-19, we hypothesize the possible relationship between the COVID-19 infection and rare blood type systems, such as the Forssman antigen system.  相似文献   
62.
Liver metallothionein expression in thioacetamide-intoxicated rats   总被引:1,自引:0,他引:1  
Metallothioneins (MT), a group of ubiquitous low molecular weight proteins, implicated primarily in metal ion detoxification, are known to be expressed during hepatocellular proliferation after partial hepatectomy in rats. In the present study, we investigated the expression of MT in a rat model of liver injury and regeneration, induced by intraperitoneal administration of thioacetamide (TAA). The animals were killed at 0, 12, 24, 36, 48, 60, 72, 84, 96, 108 and 120 hours after TAA administration. The rate of tritiated thymidine incorporation into hepatic DNA, the enzymatic activity of thymidine kinase, and the assessment of the mitotic index in hepatocytes were used as indices of liver regeneration. Liver MTs were detected immunohistochemically. TAA administration caused severe hepatic injury, followed by regeneration. MT expression became prominent in hepatocytes as early as 12 hours post-TAA administration. At 24 and 36 hours post-TAA administration intense nuclear and cytoplasmic staining of hepatocytes was found in the vicinity of necrotic areas. The maximal nuclear and cytoplasmic MT expression coincides with the peak of hepatocyte proliferative capacity, occurring at 48 and 60 hours post-TAA administration. MT expression correlated positively with the Zn content of liver tissue, but negatively with serum one, at the time of maximum hepatocyte proliferative capacity. This study suggests that MT participates in hepatocyte replication after toxin-induced liver injury.  相似文献   
63.
Type I interferons (IFNs) are pleiotropic cytokines that exert multiple effects on normal and tumor cells. These effects are supposedly mediated through the stimulation of several signal transduction pathways by type I IFNs. These include the well-studied canonical Jak-Stat pathway, largely responsible for the antiviral and growth-inhibitory activities of IFNs, as well as the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways, whose importance in IFN-induced biologic outcomes has not been precisely established. One of the effects of type I IFNs on tumor cells is the induction of programmed cell death, apoptosis, which has been studied extensively over the last decade and has been suggested to be an important effector mechanism for IFN's antitumor effects in the treatment of cancer. The aim of this review is to summarize and discuss the recent data in the field of type I IFN-induced apoptosis, with special emphasis on the molecular mechanisms of apoptosis and on the role of alternative noncanonical signaling pathways stimulated by type I IFNs in this process.  相似文献   
64.
AIMS: Over-expression of cellular metallothionein occurs frequently in human tumours but the underlying mechanism remains unknown. The aim of this study was to assess metallothionein expression in cases of lung carcinoma and to correlate it with histopathological parameters. METHODS AND RESULTS: Tumour tissue samples from 89 patients with lung carcinoma were immunostained by the streptavidin-biotin-peroxidase technique, using a monoclonal antibody against both metallothionein-1 and -2 isoforms. Positive matallothionein immunostaining was prominent in 44 out of 89 (49%) and negative in 45 out of 89 (51%) cases of lung carcinoma examined. Metallothionein positivity was prominent in 32 out of 43 (74%) cases of squamous cell lung carcinoma, and in 12 out of 35 (34%) cases of adenocarcinoma, while it was negative in all 11 cases of small-cell lung carcinoma examined, presenting a statistically significant difference between the different histological types. The intensity of metallothionein staining revealed a statistically significant difference between the squamous cell and adenocarcinoma cases examined. The pattern and extent of metallothionein staining in tumour cells and the expression of metallothionein in stromal cells were not correlated with histopathological parameters (type and grade) in metallothionein-positive cases of lung carcinoma examined. No association was found between metallothionein expression and lymph node status in the examined cases of lung carcinoma. CONCLUSIONS: Our findings indicate that expression of metallothionein was evident in squamous cell lung carcinoma and adenocarcinoma, but absent in small-cell lung carcinoma, supporting evidence for participation of this protein in the biological mechanisms underlying the carcinogenic evolution in the lung.  相似文献   
65.
BACKGROUND: High, normal and poor responders are usually defined by reference to subjectively selected estradiol E2 levels at days 4-6 and the day of hCG administration (d-hCG). The purpose of this study was to use E2 percentile curves from day 5 until d-hCG to determine high, normal and poor responders, and to predict IVF outcome. METHODS: In this retrospective study, 762 patients underwent 905 cycles with a GnRH agonist/recombinant FSH short protocol. They were divided into three groups according to their age. Percentile E2 curves according to E2 levels were plotted. High responders were those patients with E2 levels above the 90th percentile, normal responders had E2 between the 10th and 90th percentiles, and poor responders had E2 below the 10th percentile. RESULTS: IVF outcome, expressed as number of oocytes, total embryos obtained and number of high grade embryos, was significantly better for patients with E2 above the 90th percentile at d-hCG for the three age groups and at day 5 for group A (<35 years). Pregnancy rates were higher for high responders, but the difference did not reach statistical significance. CONCLUSIONS: Percentile curves can be useful in controlled ovarian stimulation cycles to define high, normal and poor responders, and also to predict IVF outcome.  相似文献   
66.
67.
The sting of Giant Asian honeybee (Apis dorsata) or Bambara in Sinhala and Karunge Kulavi in Tamil is a common environmental hazard in Sri Lanka known to cause immediate allergic reactions, which could be fatal in sensitized individuals. We reported myocardial infarction, bowel gangrene and fatal anaphylaxis in a prospectively proven case series and the association of these uncommon complications with delayed removal of stingers from the patients' skin.  相似文献   
68.
AIM: To investigate whether smoking is associated with human papilloma virus (HPV) infection. METHODS: HPV infection is considered to be a necessary condition for cervical cancer development. The study population included 1291 women, aged 25-55 years, attending cervical cancer screening. All women had a Papanicolaou (Pap) test, with liquid-based cytology (Thinprep®), an HPV-DNA test and an evaluation of smoking habits. The COBAS® 4800 system was used for HPV-DNA testing, enabling identification of the following high-risk HPV (hrHPV)-types: each of HPVs 16 and 18 separately, and HPVs 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68 as a cocktail. The evaluation of smoking habits was assessed using the smoking intensity index (SII), a variable formed as the product of cigarettes consumed per day by the days (years × 365) that a woman was a smoker, divided by 1000. RESULTS: There were 136 smokers among 238 women tested positive for hrHPV-types (HPVs 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and/or 68), and 463 smokers among 1053 hrHPV-negative women (OR = 1.7, P < 0.001). This association was attributed to the youngest age group of women, aged 25-34 years (OR = 2.3, P < 0.001), while there was no association in other age groups. The intensity of smoking (increasing SII) showed no statistically significant association with hrHPV infection. Cervical infection with HPV 16 and/or HPV 18 was also not associated with age or smoking habits. Finally, no association was found between Pap test status and smoking habits or smoking intensity. CONCLUSION: Smoking appears to be associated with hrHPV infection of the uterine cervix, particularly in younger women. Further studies should investigate whether this association is based on causality and evaluate the role of other possible co-factors.  相似文献   
69.
70.
Barge  RM; de Koning  JP; Pouwels  K; Dong  F; Lowenberg  B; Touw  IP 《Blood》1996,87(6):2148-2153
Granulocyte colony-stimulating factor (G-CSF) induces rapid phosphorylation of JAK kinases as well as activation of the p21ras route through interaction with its specific receptor (G-CSF-R). The cytoplasmic membrane-proximal region of G-CSF-R (amino acids 631 to 684) is necessary for proliferation induction and activation of JAK2. In contrast, activation of Shc and Syp, signaling molecules implicated in the p21ras signaling route, depends on the phosphorylation of tyrosine residues located in the membrane-distal region (amino acids 685 to 813) of G-CSF-R. We investigated whether G-CSF-induced activation of signaling complexes of the p21ras route depends on the function of the membrane-proximal cytoplasmic region of G-CSF-R. A G- CSF-R mutant was constructed in which tryptophan 650 was replaced by arginine and expressed in BAF3 cells (BAF/W650R). In contrast to BAF3 cell transfectants expressing wild-type G-CSF-R, BAF/W650-R cells did not proliferate and did not show activation of JAK2, STAT1, or STAT3 in response to G-CSF. Immunoprecipitations with anti-Shc and anti-Grb2 antisera showed that mutant W650R also failed to activate Syp and Shc. These data indicate that the membrane-proximal cytoplasmic domain of G- CSF-R is not only crucial for proliferative signaling and activation of JAK2 and STATs, but is also required for activation of the p21ras route, which occurs via the membrane-distal region of G-CSF-R.  相似文献   
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