[Role of glucocorticoids in pneumocystis pneumonia in patients with non-HIV infection/AIDS (HIV/AIDS) and related mechanisms]

Pneumocystis pneumonia (PCP) is an opportunistic infection caused by Pneumocystis carinii and is the most common fungal infection in HIV/AIDS patients. With the routine use of antiretroviral therapy (ART), the incidence of PCP infection in HIV/AIDS patients has decreased and the prognosis has improved significantly. On the other hand, the use of chemoradiotherapy and immunotherapy in patients with cancer, post-transplantation and autoimmune diseases are increasing dramatically, which has led to a similar increase in the incidence of PCP in these non-HIV/AIDS patients. There is a global shift in research on PCP from HIV-infected co-infected PCP (HIV-PCP) to non-HIV-infected co-infected PCP. The clinical course of non-HIV-PCP is rapid and severe, and the morbidity and mortality rates are higher than those of HIV-PCP. Studies have shown that 90% of non-HIV-PCP patients have a history of glucocorticoid use prior to infection, such as in patients with hematologic malignancies, solid organ transplants, and rheumatic diseases, and that long-term high-dose glucocorticoid use is an important risk for PCP susceptibility. Clinical practice has shown that PCP often occurs during the tapering of glucocorticoids, and a higher proportion of patients develop diffuse pulmonary lesions and, in more severe cases suffer from life-threatening acute respiratory failure. The pathogenesis of non-HIV infections associated with PCP is not yet clarified, and there is a lack of effective therapeutic practices that require further investigation.

[A randomized controlled study on the long-term efficacy of intra-cervical lymphatic immunotherapy for adult allergic rhinitis]

Objective: To determine the long-term efficacy and safety of intra-cervical lymphatic immunotherapy (ICLIT) for adult allergic rhinitis (AR) by comparing it with subcutaneous immunotherapy (SCIT). Methods: A total of 100 adult AR patients with dust mite allergy in Department of Otorhinolaryngology, First People's Hospital of Foshan from Feb 2018 to Dec 2019 were randomly divided into two groups, 50 in SCIT group [including 42 males and 8 females, aging (32.55±9.72) years] and 50 in ICLIT group [including 45 males and 5 females, aging (31.33±9.84) years]. The changes in total symptom score (total system score, TSS), nasal symptom score (total nasal symptom score, TNSS), eye symptom score (total ocular scoring system, TOSS), drug score (total medication score, TMS), and quality of life score of the two groups of patients were evaluated before and after treatment, and the adverse reactions of all patients during the treatment period were recorded. The changes in the level of dust mite specific IgE (sIgE) in the serum were evaluated. GraphPad Prism 9.0 software was used for statistical analysis. Results: In the SCIT group, 38 patients completed treatment and follow-up, with a dropout rate of 24%. In the ICLIT group, 48 patients completed treatment and follow-up, with a dropout rate of only 4%. The scores of TSS, TNSS, TOSS, TMS, and quality of life in the ICLIT group before treatment were 32.1±3.0, 27.3±3.1, 4.8±2.8, 2.3±0.9, and 68.1±28.7, respectively; After 36 months of treatment, the scores were 21.8±11.4, 18.1±9.4, 3.7±2.9, 1.3±1.1, and 36.0±26.7, respectively, which were significantly lower than those before treatment (all P<0.001). After 36 months of treatment, the TSS of the ICLIT group improved by 10.3±11.2 compared to before, while the TSS of the SCIT group improved significantly by 21.9±11.0 compared to before, with statistically significant differences between the groups (P<0.001). No serious systemic adverse reactions occurred in both groups of patients. Conclusions: ICLIT treatment for adult AR has long-term efficacy, high safety, and high compliance, but its long-term efficacy is not as good as SCIT. ICLIT can be considered as a new complementary option for AR immunotherapy.

[Study of the negative regulation of transforming growth factor beta type II receptor to inhibit the occurrence and development of liver fibrosis with miR-217]

Objective: To observe the effect of miR-217 on angiotensin II (AngII)-induced hepatic stellate cells (HSCs) activation, and carbon tetrachloride (CCl4)-induced overexpression in mice, so as to clarify miR-217 role in liver fibrosis. Methods: HSCs were stimulated with AngⅡ and the changes condition in the expression level of miR-217 were detected. HSCs were divided into control group, AngII-treated group and AngⅡ+miR-217-treated group. The expression levels of alpha-smooth muscle actin, fibroblast-specific protein 1 and collagen Ⅰ (Collagen Ⅰ) in each group were detected. The target gene of mir-217 was screened and verified by Targetscan and Dual luciferase gene reporter assay. Real-time quantitative PCR and Western blot were used to detect the effect of miR-217 on the expression level of transforming growth factor beta type Ⅱ receptor (TGFBR2). A CCl4-induced mouse liver fibrosis model was constructed. Masson staining and Sirius red staining were used to detect the effect of miR-217 overexpression on the progression of liver fibrosis in CCl4 mice. Data of two groups were compared using t-test. Data of multiple groups were statistically analyzed with one-way ANOVA. Results: The expression level of miR-217 was downregulated by AngⅡ-stimulated HSC cells. The expression levels of α-smooth muscle actin, fibroblast-specific protein 1 and Collagen Ⅰ induced by AngⅡ was inhibited by miR-217 mimics transfection. The 3'-UTR of TGFBR2 had specifically bind miR-217. The mRNA and protein expression levels of TGFBR2 was inhibited with miR-217 mimics transfection in HSCs. The overexpression of miR-217 had inhibited the expression levels of Collagen Ⅰ and Ⅲ in CCl4 mice and alleviated the progression of liver fibrosis . Conclusion: miR-217 regulates liver fibrosis by targeting TGFBR2, inhibits AngII-induced HSC activation, and slows down the process of liver fibrosis in CCl4 mice, suggesting that miR-217 may have an inhibitory effect on liver fibrosis.

The chemokine CXCL1 and its receptor CXCR2 contribute to chronic stress-induced depression in mice

Depression is increasingly recognized as an inflammatory disease, with inflammatory crosstalk in the brain contributing its pathogenesis. Life stresses may up-regulate inflammatory processes and promote depression. Although cytokines are central to stress-related immune responses, their contribution to stress-induced depression remains unclear. Here, we used unpredictable chronic mild stress (UCMS) to induce depression-like behaviors in mice, as assessed through a suite of behavioral tests. C-X-C motif chemokine ligand 1 (CXCL1)-related molecular networks responsible for depression-like behaviors were assessed through intrahippocampal microinjection of lenti-CXCL1, the antidepressant fluoxetine, the C-X-C motif chemokine receptor 2 (CXCR2) inhibitor SB265610, and the glycogen synthase kinase-3β (GSK3β) inhibitor AR-A014418. Modulation of apoptosis-related pathways and neuronal plasticity were assessed via quantification of cleaved caspase-3, B-cell lymphoma 2-associated X protein, cAMP response element-binding protein (CREB), and brain-derived neurotrophic factor (BDNF) protein expression. CXCL1/CXCL2 expression was correlated with depression-like behaviors in response to chronic stress or antidepressant treatment in the UCMS depression model. Intrahippocampal microinjection of lenti-CXCL1 increased depression-like behaviors, activated GSK3β, increased apoptosis pathways, suppressed CREB activation, and decreased BDNF. Administration of the selective GSK3β inhibitor AR-A014418 abolished the effects of lenti-CXCL1, and the CXCR2 inhibitor SB265610 prevented chronic stress-induced depression-like behaviors, inhibited GSK3β activity, blocked apoptosis pathways, and restored BDNF expression. The CXCL1/CXCR2 axis appears to play a critical role in stress-induced depression, and CXCR2 is a potential novel therapeutic target for patients with depression.-Chai, H.-H., Fu, X.-C., Ma, L., Sun, H.-T., Chen, G.-Z., Song, M.-Y., Chen, W.-X., Chen, Y.-S., Tan, M.-X., Guo, Y.-W., Li, S.-P. The chemokine CXCL1 and its receptor CXCR2 contribute to chronic stress-induced depression in mice.

Association between the pre-miR-196a2 rs11614913 polymorphism and gastric cancer susceptibility in a Chinese population

We did a case-control study to provide a more comprehensive evaluation of the association of the pre-miR-196a2 rs11614913 polymorphism with gastric cancer. Between January 2013 and December 2014, 182 patients newly diagnosed with primary gastric cancer and 182 control subjects were recruited at Zhengzhou People's Hospital. For SNP genotyping, we used the Assay Designer 3.1 to design the primers of polymerase chain reaction. Using the chi-square test, we found that patients with gastric cancer were more likely to be alcohol drinkers (χ(2) = 4.4, P = 0.04), to have a family history of cancer in the first relatives (χ(2) = 5.29, P = 0.02), and to be infected with Helicobacter pylori (χ(2) = 23.39, P < 0.001). A significant difference in the genotype distributions of rs11614913 was observed in our study (χ(2) = 6.66, P = 0.04). By logistic regression analysis, we found that the CC genotype of rs11614913 was associated with an increased risk of gastric cancer in a codominant model (OR = 2.68, 95%CI = 1.17-6.44). By stratification analysis, we found that the CC genotype was associated with a strongly increased risk of gastric cancer in drinkers when compared with the TT+TC genotype (OR = 5.63, 95%CI = 1.54-30.76). In conclusion, the results of our study suggest an association between the rs11614913 gene polymorphism and an elevated risk of gastric cancer, especially in drinkers.

Association between ERCC5 gene polymorphisms and gastric cancer risk in a Chinese population

We conducted a hospital-based case-control study to investigate the association between 3 common SNPs in the ERCC5 gene (rs1047768, rs751402, and rs17655) and the risk of developing gastric cancer. Between January 2013 and December 2014, samples were collected from 216 gastric cancer patients and 216 control subjects. ERCC5 rs1047768, rs751402, and rs17655 polymorphisms were genotyped by polymerase chain reaction combined with restriction fragment length polymorphism analysis. By conditional logistic regression analysis, the GG genotype of rs17655 was found to be associated with an elevated risk of gastric cancer in a codominant model, and the adjusted OR (95%CI) was 1.96 (1.10-3.50). Moreover, in a dominant model, the CG + GG genotype of rs17655 was correlated with an increased risk of gastric cancer compared to the CC genotype (OR = 1.48; 95%CI = 1.00-2.22). rs1047768 and rs751402 were not significantly correlated with an increased or decreased gastric cancer risk.

Artemisinin biosynthesis enhancement in transgenic Artemisia annua plants by downregulation of the β-caryophyllene synthase gene

Artemisinin is an effective antimalarial drug isolated from the medicinal plant Artemisia annua L. Due to its increasing market demand and the low yield in A. annua, there is a great interest in increasing its production. In this paper, in an attempt to increase artemisinin content of A. ANNUA by suppressing the expression of β-caryophyllene synthase, a sesquiterpene synthase competing as a precursor of artemisinin, the antisense fragment (750 bp) of β-caryophyllene synthase cDNA was inserted into the plant expression vector pBI121 and introduced into A. annua by Agrobacterium-mediated transformation. PCR and Southern hybridization confirmed the stable integration of multiple copies of the transgene in 5 different transgenic lines of A. annua. Reverse transcription PCR showed that the expression of endogenous CPS in the transgenic lines was significantly lower than that in the wild-type control A. annua plants, and β-caryophyllene content decreased sharply in the transgenic lines in comparison to the control. The artemisinin content of one of the transgenic lines showed an increase of 54.9 % compared with the wild-type control. The present study demonstrated that the inhibition pathway in the precursor competition for artemisinin biosynthesis by anti-sense technology is an effective means of increasing the artemisinin content of A. annua plants.

Human umbilical vein-derived dopaminergic-like cell transplantation with nerve growth factor ameliorates motor dysfunction in a rat model of Parkinson's disease

Mesenchymal stem cells are capable of differentiating into dopaminergic-like cells, but currently no report has been available to describe the induction of human umbilical vein mesenchymal stem cells (HUVMSCs) into dopaminergic-like cells. In this study, we induced HUVMSCs in vitro into neurospheres constituted by neural stem-like cells, and further into cells bearing strong morphological, phenotypic and functional resemblances with dopaminergic-like cells. These HUVMSC-derived dopaminergic-like cells, after grafting into the brain of a rat model of Parkinson's disease (PD), showed a partial therapeutic effect in terms of the behavioral improvement. Nerve growth factor was reported to improve the local microenvironment of the grafted cells, and we therefore further tested the effect of dopaminergic-like cell grafting combined with nerve growth factor (NGF) administration at the site of cell transplantation. The results showed that NGF administration significantly promoted the survival of the grafted cells in the host brain and enhanced the content of dopaminergic in the local brain tissue. Behavioral test demonstrated a significant improvement of the motor function of the PD rats after dopaminergic-like cell grafting with NGF administration as compared with that of rats receiving the cell grafting only. These results suggest that transplantation of the dopaminergic-like cells combined with NGF administration may represent a new strategy of stem cell therapy for PD.

Identification of a Polygonum cuspidatum three-intron gene encoding a type III polyketide synthase producing both naringenin and p-hydroxybenzalacetone

Benzalacetone synthase (BAS) is a member of the plant-specific type III PKS superfamily that catalyzes a one-step decarboxylative condensation of 4-coumaroyl-CoA with malonyl-CoA to produce p-hydroxybenzalacetone. In our recent work (Ma et al. in Planta 229(3):457-469, 2008), a three-intron type III PKS gene (PcPKS2) was isolated from Polygonum cuspidatum Sieb. et Zucc. Phylogenetic and functional analyses revealed this recombinant PcPKS2 to be a BAS. In this study, another three-intron type III PKS gene (PcPKS1) and its corresponding cDNA were isolated from P. cuspidatum. Sequence and phylogenetic analyses demonstrated that PcPKS1 is a chalcone sythase (CHS). However, functional and enzymatic analyses showed that recombinant PcPKS1 is a bifunctional enzyme with both, CHS and BAS activity. DNA gel blot analysis indicated that there are two to four CHS copies in the P. cuspidatum genome. RNA gel blot analysis revealed that PcPKS1 is highly expressed in the rhizomes and in young leaves, but not in the roots of the plant. PcPKS1 transcripts in leaves were inducible by pathogen infection and wounding. BAS is thought to play a crucial role in the construction of the C(6)-C(4) moiety found in a variety of phenylbutanoids, yet so far phenylbutanoids have not been isolated from P. cuspidatum. However, since PcPKS1 and PcPKS2 (Ma et al. in Planta 229(3):457-469, 2008) have been identified in P. cuspidatum, it is possible that such compounds are also produced in that plant, albeit in low concentrations.

[Culture and identification of neural stem cells derived from the subventricular zone of adult mice]

OBJECTIVE

To establish a method for culturing and identifying neural stem cells (NSCs) derived from the subventricular zone (SVZ) in adult mice.

METHODS

NSCs were isolated from the SVZ of adult mouse brain and cultured in serum-free medium. Cell cloning and BrdU incorporation were performed to identify the self-renewal and proliferative capacity of the NSCs. Fluorescence immunocytochemistry was used to examine the expressions of the NSC markers nestin and SOX2, neuronal marker Tuj1, astrocyte marker GFAP and oligodendrocyte marker NG2. The expressions of nestin and SOX2 were further examined by Western blotting and RT-PCR.

RESULTS

NSCs with self-renewal and proliferative capacity were obtained from the SVZ of adult mice and grown as floating neurospheres. The NSCs expressed nestin and SOX2 and could differentiated into Tuj1-positive neurons, GFAP-positive astrocytes and NG2-positive oligodendrocytes.

CONCLUSION

This method allows simple and stable culture of NSCs from the SVZ of adult mice.

[Time course of calpain activity changes in rat neurons following fluid percussion injury and the interventional effect of mild hypothermia]

OBJECTIVE

To investigate the time course of calpain activity changes in rat neurons following fluid percussion injury (FPI) under normothermia (37 degrees celsius;) and mild hypothermia (32-/+0.5) degrees celsius;.

METHODS

In vitro cultured rat neurons were subjected to FPI followed by application of mild hypothermia for intervention at different time points, and the changes in intraneuronal calpain activity following FPI and the interventional effect of mild hypothermia on calpain activity were evaluated by UV-spectrophotometry at different time points.

RESULTS

Remarkable changes occurred in calpain activity in the neurons following FPI at 37 degrees celsius;, and mild hypothermia produced obvious interventional effect on calpain activity in close relation to the timing of intervention initiation.

CONCLUSION

Intraneuronal calpain activity changes following FPI are involved in the pathological process of cellular injury, and mild hypothermia might offer protection against traumatic brain injury to some extent by regulating calpain activity. The interventional effect of mild hypothermia is associated with the timing of the intervention initiation.

Chemical diversity in opisthobranch molluscs from scarcely investigated Indo-Pacific areas

Opisthobranch molluscs with both a rich variety of secondary metabolites and great biomedical potential represent the most intensively studied group of molluscs in natural product chemistry. We review here the chemical investigations into secondary metabolites of "sea slugs" from less-studied Indian, Chinese and Egyptian coasts, giving an overview of their most relevant biological activities. In addition to the biomedical interest of the metabolites, in which both structures and organisms often lose their own importance, this chapter emphasizes the phyletic and geographic distribution of the compounds in order to provide a further informational base for chemotaxonomical generalizations.

Cloning and functional expression of the mucrosobin protein, a beta-fibrinogenase of Trimeresurus mucrosquamatus (Taiwan Habu)

A venom-specific cDNA encoding for a thrombin-like enzyme designated as mucrosobin has been cloned and sequenced from the cDNA library of the venomous gland of Trimeresurus mucrosquamatus. The full-length cDNA of mucrosobin was assembled by oligonucleotide screening and 5'-rapid amplification of cDNA ends. The amino acid sequence deduced from the cDNA consists of 257 amino acid residues with a putative signal peptide of 24 residues. It is highly homologous to the other thrombin-like enzymes (batroxobin, mucofirase, and calobin), suggesting that it is a serine proteinase with a conserved catalytic triad of His(41), Asp(84) and Ser(179) in the deduced form of mucrosobin protein. Northern blot analysis revealed that the mucrosobin gene encodes an mRNA of 1.5 kb and suggested a tissue-specific expression in the venomous gland. In an effort to study the biological property of mocrosobin, we have expressed the 28-kDa protein as inclusion bodies in Escherichia coli. For analyzing enzymatic activity, the inclusion bodies were solubilized and the recombinant protein was refolded with a two-step dialysis protocol. The refolded recombinant protein exhibited a specific beta-fibrinogenolytic activity. This study offers a possibility of using genetic engineering to acquire a functional snake venom protein with therapeutic potential.

Cloning and characterization of a complementary DNA encoding a human epididymis-associated disintegrin and metalloprotease 7 protein

Mammalian spermatozoa interact with the proteins secreted by the epididymis to develop fertility. Transmembrane proteins that possess a disintegrin and metalloprotease (ADAM) domains are shown to be closely related to spermatogenesis and fertilization. Our previous study demonstrated that GP-83, a glycoprotein secreted by the epididymis, was conjugated to mature sperm. In this study, a 2.1-kilobase (kb) GP-83-expressing insert was isolated from a cDNA library of human epididymis by immunoscreening using GP-83-specific antiserum. The 5' end rapid amplification of cDNA ends (RACE) and 3'-RACE of the 2.1-kb insert elucidated two isoforms of GP-83-encoding cDNA sequences, an alpha-form of 3451 base pairs (bp) and beta-form of 2643 bp. Both forms exhibit the same open reading frame of 2262 bp predicting a peptide of 754 amino acid residues. Deduced amino acid sequence revealed signal sequence, prodomain, metalloproteinase, disintegrin, cysteine-rich, epidermal growth factor-like, transmembrane, and cytoplasmic domains. The GP-83-encoding sequence was recognized as human ADAM7 due to significant homology to other ADAM7s. According to the DNA sequences elucidated in the Human Genome Project, h-ADAM7 was located at chromosome 8p22. Ex vivo expression confirmed that h-ADAM7 cDNA did encode GP-83. Northern blot analysis revealed two transcripts of 4 kb and 3 kb in the epididymis, but not in testis or other major tissues. These results indicate that the GP-83-encoding gene is a human epididymis-associated ADAM7 gene (human ADAM7, h-ADAM7) and may be involved in the sperm-egg interaction.

Purification of GP-83, a glycoprotein secreted by the human epididymis and conjugated to mature spermatozoa

Epididymal secretions are critical for mammalian spermatozoa to acquire both forward motility and an ability to recognize and penetrate oocytes. Previous studies identified two glycoproteins, GP-83 and GP-39, which were secreted by the human epididymis and may be related to maturation of sperm function. In this study, GP-83 was purified from human seminal fluid by DEAE-ion exchange, gel filtration chromatography and preparative gel elution. The isoelectric point (pI) of purified GP-83 was 6.57. Monospecific antiserum to GP-83 was induced in male New Zealand rabbits and confirmed on immunoblots. GP-83 was found in fluid, tissue and sperm extracts of corpus and cauda epididymis, but not in the caput. Immunohistochemical localization identified GP-83 in the luminal contents and in the supranuclear region and cell membrane of principal cells of the corpus and cauda epididymis. GP-83 was found on the anterior acrosome in ejaculated spermatozoa, and shifted to the equatorial region after capacitation and the acrosome reaction.

New Hurghamids from a Red Sea sponge of the genus Hippospongia

Three new N-acyl-2-methylene-beta-alanine methyl esters, Hurghamides E-G (5-7), were isolated from a Red Sea sponge Hippospongia sp. Their structures were elucidated by extensive spectroscopic studies.

Three new butenolide lipids from the caribbean gorgonian pterogorgia anceps

Three novel fatty acid derivatives (1-3), containing one or two butenolide moieties, were isolated from the Caribbean gorgonian Pterogorgia anceps and chemically characterized by spectroscopic methods and comparison with known compounds. The new molecules were structurally related to ancepsenolide (4), a typical metabolite from Pterogorgia species, which was not detected in this collection of P. anceps.

Cloning and expression of a cysteine-rich venom protein from Trimeresurus mucrosquamatus (Taiwan habu)

A full-length cDNA for cysteine-rich venom protein (CRVP) was constructed by immunoscreening and 5'-rapid amplification of cDNA ends from a cDNA library of venom gland of Trimeresurus mucrosquamatus. The predicted CRVP consisted of 183 amino acid residues including a putative signal peptide of 21 residues. Northern blot hybridization suggested the tissue-specific expression in venom gland and its corresponding length of cDNA. The predicted amino acid sequence of CRVP was homologous to a rat epididymal metalloprotein and a lizard helothermine. Amino acid sequence analysis suggested that CRVP may be a venom metalloprotein targeted against ryanodine receptors and Ca2+ release. Moreover, CRVP expressed in Escherichia coli exhibited the same antigenicity as their native venom forms of T. mucrosquamatus. This is the first report in the cloning and expression of a CRVP from the venom gland of T. mucrosquamatus.

Structure/function relationship study of Gln156, Glu160 and Glu189 in the active site of trichosanthin

Trichosanthin is a protein used medicinally in China for abortifacient purposes. It is also an RNA N-glycosidase which inactivates eukaryotic ribosomes by removing adenine4324 from 28S rRNA. Site-directed mutagenesis was performed to probe the role of Gln156, Glu160 and Glu189 in the active site of trichosanthin. The purified altered proteins were assayed for their potency in inhibiting in vitro protein synthesis. The data indicate Glu160 is involved in the catalytic reaction. Kinetics studies suggest the carboxylate group of Glu160 serves to stabilize the transition-state complex. Similar to ricin A, the variant [E160A]trichosanthin is more potent than [E160D]trichosanthin. This is because Glu189 serves as a back-up of the carboxylate group in case Glu160 is mutated to alanine. However, removal of Glu189 in the presence of Glu160 does not affect the ID50 value drastically. An activity of 1800-fold less than that of the wild-type protein was found when both Glu160 and Glu189 were changed to alanine, indicating that some other residues in the active site are also taken part in the lowering of energy barrier for the catalytic reaction. Although Gln156 is highly conserved in related proteins, its mutation to alanine only slightly decreases the activity, showing that this residue does not participate directly in catalysis.

Characterization of a structurally tricistronic gene of human cytomegalovirus composed of U(s)18, U(s)19, and U(s)20

A tricistronic gene mapped between 0.91 and 0.93 map units within the EcoRI D fragment of the human cytomegalovirus unique short region (U(s)) has been cloned, sequenced, and expressed in vitro. Cloned cDNAs of 2.3, 1.8, and 1.1 kb derived from this region were isolated from a lambda gt11 cDNA library made from virus-infected fibroblasts and used for this study. Two major classes of 3'-coterminal mRNAs, 2.8 and 1.1 kb, were transcribed from this region. Sequence analysis of the cDNAs and the upstream genomic DNA revealed three open reading frames (ORFs), U(s)18, U(s)19, and U(s)20, and a common polyadenylation signal located 15 bases upstream of the poly(A) tail of both the 2.85- and 1.1-kb mRNAs. Protein structure analyses predicted the existence of multiple hydrophobic moieties, suggesting that the U(s)18, U(s)19, and U(s)20 polypeptides were transmembrane proteins. The major transcription initiation site, determined by primer extension and S1 nuclease mapping, for the 2.85-kb transcript was located right at the first initiation codon of the U(s)20 ORF. There was no typical TATA box or CAAT box upstream of the 2.85-kb mRNA cap site except for a TATAAGA sequence that was found about 210 bp downstream from the major cap site. The 1.1-kb transcript was initiated 33 bp upstream of the U(s)18 translation initiation site, and an atypical TATA box sequence (GATAAGA) was found 22 bp upstream of the transcription start site. Differences in transcription kinetics and sensitivities to metabolic inhibitors suggest that they were regulated by different mechanisms; the 2.85-kb mRNA belongs to the early (beta) class of transcripts, while the 1.1-kb mRNA is a late (gamma) message. Subgenomic DNA segments derived from the U(s)18, U(s)19, and U(s)20 ORFs were subcloned and overexpressed in Escherichia coli as fusion proteins with glutathione-s-transferase. Western immunoblot analysis with antibodies against the U(s)18, U(s)19, and U(s)20 fusion proteins detected virus-specific polypeptides with molecular sizes of 36, 32, and 43 kDa, respectively. All three antibodies also exhibited a positive immunofluorescence reaction with human cytomegalovirus-infected cells harvested at late stages of infection.

[Behavior of intermediate filaments in human epithelial cells during mitosis]

By indirect immunofluorescence microscopy and electron microscopy, we studied the behavior of intermediate filaments during mitosis in three human epithelial cell lines, derived from normal epidermis (PcaSE-1, from a cancer patient), stratified epithelium (CNE, from nasopharyngeal carcinoma) and simple epithelium (SPC-A-1 from lung adenocarcinoma) respectively. CNE cells and SPC-A-1 cells express two different intermediate filament systems; keratin filaments and vimentin filaments, but PcaSE-1 cells only express keratin filaments. The keratin filament system in PcaSE-1 cells remained intact and encircled the developing mitotic spindle as the cells entered mitosis. In contrast, in CNE cells and SPC-A-1 cells, keratin filaments appeared to disassemble into amorphous cytoplasmic bodies during mitosis. However, their vimentin filaments remained morphologically intact throughout mitosis. We propose; (1) The disassembly of keratin filaments in mitotic epithelial cells is more or less associated with the degree of their cell malignancy rather than with the abundance of keratin filaments in interphase. (2) Intermediate filaments may be involved in the positioning and/or centering of the spindle during mitosis. (3) The possible function of vimentin filament system in CNE cells is positioning and orientation of chromosomes.

Physical properties of some snake plasma albumins

The albumin-like proteins were purified from the plasma of three terrestrial elapids and two sea snakes. The albumin-like fraction averaged 25% (range: 21-30%) in concentration of the total plasma proteins as determined by densitometer. The physical properties of the albumin-like proteins purified from these snakes were compared. These properties, e.g. electrophoretic mobility, isoelectric point, extinction coefficient, and molecular weight, were shown to be strikingly similar to those of human plasma albumin. The physical properties of the plasma albumins of the snakes studied are similar to one another. This similarity does not explain our previous observation that Naja albumin is considerably remote immunologically from those of other elapids (Mao et al., 1983).

Hemoglobin fingerprint correspondence and relationships of Taiwan common venomous snakes

Peptide fingerprints of tryptic digests of globins of 6 venomous snakes representing 2 families and 3 subfamilies were compared. The evolutionary relationships of these snakes derived from globin peptide fingerprints are consistent with those based upon morphological criteria. Globins of Trimeresurus mucrosquamatus and Trimeresurus s. stejnegeri are most alike, differing in 19 components. The average from globins of the 2 Trimeresurus compared with Agkistrodon shows a difference of 24 components. The average difference between the 3 crotalines and Vipera is 26. Naja globin is most divergent in structure, differing from those of the 4 viperids by 42-44 peptides, and from that of Bungarus by 32 peptides.