Insecticidal Activities and Phenological Variations of Characteristic Component from Michelia yunnanensis

Volatile secondary metabolites of plants interact with environments heavily. In this work, characteristic components of Michelia yunnanensis essential oils (EOs) were isolated, purified and identified by column chromatography, GC-MS and NMR. Leaves of M. yunnanensis were collected monthly and extracted for EOs to investigate chemical and insecticidal activity variations as well as potential influencing environments. Different organs were employed to reveal distribution strategies of characteristic components. Results of insecticidal activities showed that all EOs samples exerted stronger contact activity to Lasioderma serricorne, but repellent effect was more efficient on Tribolium castaneum. One oxygenated sesquiterpene was isolated from EOs, basically it could be confirmed as (+)-cyclocolorenone (1). It exerted contact toxicity to L. serricorne (LD 50 = 28.8 μg/adult). Chemical analysis showed that M. yunnanensis leaves in reproductive period would produce and accumulate more 1 than in vegetative period. Moreover, reproductive organs (flowers and fruits) contained more 1 than vegetative organs (leaves and twigs). Partial correlation analysis indicated that temperature-related elements positively correlated with the relative content of 1.

Essential Oils from Different Parts of Magnolia laevifolia: Chemical Constituents and Insecticidal Activities against Liposcelis bostrychophila

Many synthetic pesticides were used to control a severe storage pest, booklouse (Liposcelis bostrychophila). However, considering the environmental impact, plant secondary metabolites were acceptable alternatives. An endemic plant, Magnolia laevifolia, has a significant and unique odour, so its essential oil (EO) could be an option for bio-pesticide development. This study extracted EOs from leaves, flowers, carpels and seeds of M. laevifolia. The common and major compound of EOs was isocapnell-9-en-8-one, which was present at 17.7 to 91.6 % in these four parts. We found no regular pattern in the composition of EO in terms of parts and collection time according to principal component analysis. The contact and repellent activities of EOs against the booklouse were then conducted. Leaves and flowers' EOs collected in the flowering stage had the best contact toxicity. The percent repellency values of the EOs from different parts of M. laevifolia reached above 80 % after 2 and 4 h exposure at 63.17 nL/cm2 , with the same levels as DEET (p<0.05). It was shown that parts of plants and collecting time could influence the insecticidal activities of M. laevifolia EOs against booklouse, but collecting time played a significant decisive role in the contact test.

Composition and Insecticidal Activity of Elsholtzia kachinensis Prain, a Traditional Vegetable and Herbal Medicine

In recent years, secondary metabolites of plants have attracted researchers' interest as a substitute for synthetic insecticides with many advantages. Elsholtzia kachinensis is an annual herb with medicinal and edible value. In this study, the essential oil (EO) of the aerial part of E. kachinensis was extracted by hydrodistillation, and GC-MS analysed essential oil components. The results show that carvone and dehydroelsholtzia ketone are the main components of the essential oil, accounting for 32.298% and 31.540%, respectively. EO, carvone and dehydroelsholtzia ketone are used to determine the effects against stored-product insects Lasioderma serricorne, Tribolium castaneum, Sitophilus oryzae and Liposcelis bostrychophila. The essential oil showed the most vital contact and fumigation toxicity to L. serricorne, of which LD₅₀ and LC₅₀ values were 3.85 μg/adult and 7.74 mg/L air, respectively. S. oryzae did not show repellent activity, but the repellent rate of the other three species reached 90% under EO treatment at a concentration of 78.63 nL/cm². Therefore, the essential oil of E. kachinensis has an insecticidal effect and has the potential to be developed as a new eco-friendly insecticide.

[Ultrasonographic features and clinical pathological of liver metastasis in patients with melanoma]

Objective: To investigate the ultrasonographic features and clinical pathological of liver metastasis in patients with melanoma. Methods: Thirteen patients with liver metastasis from melanoma treated in Tianjin Medical University Cancer Institute and Hospital from 2013 to 2019 were selected, and their ultrasonographic and clinicopathological characteristics were analyzed retrospectively. Results: Eleven of the 13 patients had multiple liver lesions. The maximum diameter of the lesions was (5.89±2.73) cm. Five cases of lesions were mixed echo (3 cases with high melanin content), 4 cases of lesions were hyperechoic (3 cases with low melanin content), 3 cases of lesions were hypoechoic (all with high melanin content), 1 case of lesions were equal echo (with high melanin content). The lesions in 11 patients had clear boundaries, while other 2 patients lacked the clear borders. Cystic areas were present in the lesions of 3 patients. Six cases had irregular lesions (lobulated), and 7 cases had regular lesions (round, oval). There were acoustic halos around the lesion in 9 cases and smooth and uneven acoustic halos in 5 cases. The results of immunohistochemistry showed that 11 cases were positive for S-100, HMB45 and Melan-A. One patient was not tested for HMB45, while S-100 and Melan-A were positive. One patient did not undergo Melan-A test, while S-100 and HMB45 were positive. Conclusion: Most of the liver metastases of melanoma are mixed echo or hyperechoic, most of them are nodular with clear boundaries combined with vocal halo, and a few of the lesions have cystic areas.

Sesquiterpenoid-rich Essential Oils from Two Magnolia Plants: Contact and Repellent Activity to Three Stored-product Insects

Stored products have been damaged by insects. Multiple approaches for pest management are employed. Among these approaches, botanical insecticide is an emerging one. This work investigated the pest management potential of Magnolia coriacea and Magnolia macclurei essential oils (EOs) to three major stored-product insects, namely the red flour beetle, cigarette beetle and booklouse. Magnolia coriacea and M. macclurei EOs showed promising contact toxicity to the cigarette beetle, with LD₅₀ values of 11.7 and 12.3 μg/adult. The contact toxicity of M. coriacea EOs to the booklouse (LC₅₀ = 95.5 μg/cm²) was much stronger than that of M. macclurei EOs (LC₅₀ = 245.4 μg/cm²). To explore the contribution of individual compounds to insecticidal activity of EOs, chemical analysis was performed by GC-MS. Results showed that nerolidol (27.84%), agarospirol (18.34%), elixene (15.84%) and helminthogermacrene (12.69%) were major compounds of M. coriacea EOs, β-guaiene (60.31%) and elixene (20.42%) dominated in M. macclurei EOs. Nerolidol and β-guaiene showed contact activity to three insect species. Nerolidol showed stronger contact toxicity to the red flour beetle and cigarette beetle than M. coriacea EOs did, both samples were similar to the booklouse. β-Guaiene was much stronger to the red flour beetle and booklouse, but weaker to the cigarette beetle than M. macclurei EOs did. The repellent effects of EOs and compounds were at various levels. Generally, results suggested that the contact toxic potential of samples could serve as management for the cigarette beetle and booklouse, while repellent effect would be used to control the red flour beetle.

Insecticidal and Repellent Activity of Thymus quinquecostatus Celak. Essential Oil and Major Compositions against Three Stored-Product Insects

Thymus quinquecostatus Celak. of the Lamiaceae family has a long history of dual use of medicine and food with high economic value, and has been proved to have good antioxidative, antimicrobial, and antidiabetic activities. Essential oil (EO) extracted from the aerial part of T. quinquecostatus was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC/MS) and GC. Totally 45 compounds were identified accounting for 98.5 % of the EO. The major constituents of the EO were linalool (52.003 %), borneol (10.911 %) and anethole (5.325 %). Fumigant, contact and repellent activity of T. quinquecostatus essential oil (EO) against Tribolium castaneum (Coleoptera: Tenebrionidae), Lasioderma Serricorne (Coleoptera: Anobiidae), Liposcelis bostrychophila (Psocoptera: Liposcelididae) were evaluated in this work. T. quinquecostatus EO and three major constituents showed varying degrees of insecticidal and repellent activities to three stored-product insects. Anethole stated the best fumigant and contact activity than others did to all three insect species. EO and compounds showed general repellent activity against three target insects. This work suggests that the EO of T. quinquecostatus has promising potential to be developed into botanical pesticides and repellents controlling pest damage in warehouses and grain stores.

Loss of function of NF1 is a mechanism of acquired resistance to endocrine therapy in lobular breast cancer

Background

Invasive lobular carcinoma (ILC) as a disease entity distinct from invasive ductal carcinoma (IDC) has merited focused studies of the genomic landscape, but those to date are largely limited to the assessment of early-stage cancers. Given that genomic alterations develop as acquired resistance to endocrine therapy, studies on refractory ILC are needed.

Patients and methods

Tissue from 336 primary-enriched, breast-biopsied ILC and 485 estrogen receptor (ER)-positive IDC and metastatic biopsy specimens from 180 ILC and 191 ER-positive IDC patients was assayed with hybrid-capture-based comprehensive genomic profiling for short variant, indel, copy number variants, and rearrangements in up to 395 cancer-related genes.

Results

Whereas ESR1 alterations are enriched in the metastases of both ILC and IDC compared with breast specimens, NF1 alterations are enriched only in ILC metastases (mILC). NF1 alterations are predominantly under loss of heterozygosity (11/14, 79%), are mutually exclusive with ESR1 mutations [odds ratio = 0.24, P < 0.027] and are frequently polyclonal in ctDNA assays. Assessment of paired specimens shows that NF1 alterations arise in the setting of acquired resistance. An in vitro model of CDH1 mutated ER-positive breast cancer demonstrates that NF1 knockdown confers a growth advantage in the presence of 4-hydroxy tamoxifen. Our study further identified a significant increase in tumor mutational burden (TMB) in mILCs relative to breast ILCs or metastatic IDCs (8.9% >20 mutations/mb; P < 0.001). Most TMB-high mILCs harbor an APOBEC trinucleotide signature (14/16; 88%).

Conclusions

This study identifies alteration of NF1 as enriched specifically in mILC. Mutual exclusivity with ESR1 alterations, polyclonality in relapsed ctDNA, and de novo acquisition suggest a role for NF1 loss in endocrine therapy resistance. Since NF1 loss leads to RAS/RAF kinase activation, patients may benefit from a matched inhibitor. Moreover, for an independent subset of mILC, TMB was elevated relative to breast ILC, suggesting possible benefit from immune checkpoint inhibitors.

Contact toxicity and repellent efficacy of Valerianaceae spp. to three stored-product insects and synergistic interactions between two major compounds camphene and bornyl acetate

In this work, the essential oil (EO) and supercritical CO₂ fluid extract (SF extract) of four Valerianaceae plants (Valeriana officinalis L., Valeriana officinalis L. var. latifolia Miq., Valeriana jatamansi Jones and Nardostachys chinensis Bat.) were chemically characterized. GC-MS analysis identified 74 compounds, representing 35.2%-82.4% of the total EOs and SF extracts. The EO was dominated by low-molecular-weight components while the SF extract was rich in fatty acids. Bornyl acetate and camphene were the characteristic compounds in EO and SF extracts. The efficacy of six extracts against three stored-product insects was investigated. In contact assays, V. officinalis exhibited strongest toxicity to red flour beetle (LD₅₀ = 10.0 μg/adult), and V. jatamansi EO was the most active one against the cigarette beetle (LD₅₀ = 17.6 μg/adult), while V. officinalis var. latifolia EO showed outstanding efficacy against the booklouse (LD₅₀ = 40.2 μg/cm²). Binary mixtures of two major compounds (camphene and bornyl acetate) were assessed for the contact toxicity to the red flour beetle. Additive effect existed in the natural proportion of V. officinalis, and synergism was observed in that of V. officinalis var. latifolia. This work confirmed the insecticidal efficacy of the species of the Valerianaceae family, and it would offer some information for the development of botanical insecticide.

Toxicity and repellent activity of essential oil from Mentha piperita Linn. leaves and its major monoterpenoids against three stored product insects

The essential oil (EO) from leaves of Mentha piperita was extracted by hydrodistillation. Twenty-one chemical components, accounting for 97.5% of the total oil, were determined by GC-MS and GC-FID. The major chemical components included menthol (41.6%), L-menthone (24.7%), isomenthol (6.3%), and limonene (5.0%). The bioactivity of the obtained EO and its two major components against Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila adults were evaluated by fumigation, contact, and repellent activity bioassay. The EO showed significant fumigation and contact toxicity against T. castaneum (LC₅₀ = 18.1 mg/L air and LD₅₀ = 2.9 μg/adult, respectively), L. serricorne (LC₅₀ = 68.4 mg/L air and LD₅₀ = 12.6 μg/adult, respectively), and L. bostrychophila (LC₅₀ = 0.6 mg/L air and LD₅₀ = 49.8 μg/adult, respectively) adults. Meanwhile, the repellent effect of the EO on T. castaneum and L. serricorne adults was comparable to that of the positive control at the highest tested concentration. Menthol and L-menthone were two major components in total oil. Among them, L-menthone exhibited significant insecticidal activity on target insects, and menthol showed notable repellent effects. The results indicated that the EO of M. piperita leaves and two tested components have potential to be developed as natural insecticides and repellents for the control of stored product insect pests. Graphical abstract.

Insecticidal and repellent efficacy against stored-product insects of oxygenated monoterpenes and 2-dodecanone of the essential oil from Zanthoxylum planispinum var. dintanensis

Essential oils (EOs) extracted from leaves (EL) and fruit pericarp (EFP) of Zanthoxylum planispinum var. dintanensis were analyzed for their chemical composition by GC-MS technique and evaluated for their fumigant, contact toxicity and repellency against three stored-product insects, namely Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila adults. Results of GC-MS analysis manifested that EL and EFP of Z. planispinum var. dintanensis were mainly composed of oxygenated monoterpenes. Major components included linalool, sylvestrene and terpinen-4-ol. The obvious variation observed between two oil samples was that EL contained 2-dodecanone (11.52%) in addition to the above mentioned components, while this constituent was not detected in EFP. Bioassays of insecticidal and repellent activities were performed for EL, EFP as well as some of their individual compounds (linalool, terpinen-4-ol and 2-dodecanone). Testing results indicated that EL, EFP, linalool, terpinen-4-ol and 2-dodecanone exhibited potent insecticidal and repellent activities against the three target insects selected. Among the three individual compounds, 2-dodecanone was significantly toxic to T. castaneum (LD₅₀ = 5.21 μg/adult), L. serricorne (LD₅₀ = 2.54 μg/adult) and L. bostrychophila (LD₅₀ = 23.41 μg/cm²) in contact assays and had beneficial repellent effects on L. serricorne at 2 and 4 h post-exposure. The anti-insect efficacy of Z. planispinum var. dintanensis EO suggests it has potential to be used as botanical insecticide or repellent to control pest damage in warehouses and grain stores.

Efficacy of bornyl acetate and camphene from Valeriana officinalis essential oil against two storage insects

The essential oil was extracted from the roots of Valeriana officinalis L. by hydrodistillation. The qualitative and quantitative analysis of its chemical constituents was conducted on GC-MS and GC-FID in this study. Seventeen compounds were detected and the major constituents included bornyl acetate (48.2%) and camphene (13.8%). The toxic and repellent effects of the essential oil and its two major constituents were evaluated on Liposcelis bostrychophila and Tribolium castaneum. The results of bioassays indicated that the essential oil showed the promising fumigant and contact toxicity against L. bostrychophila (LC₅₀ = 2.8 mg/L air and LD₅₀ = 50.9 μg/cm², respectively) and the notable contact effect on T. castaneum (LD₅₀ = 10.0 μg/adult). Meanwhile, the essential oil showed comparable repellent effect on T. castaneum at all testing concentrations. Bornyl acetate and camphene also exhibited strong fumigant and contact toxicity against both species of pests (LC₅₀ = 1.1, 10.1 mg/L air and LD₅₀ = 32.9, 701.3 μg/cm² for L. bostrychophila; > 126.3, 4.1 mg/L air, and 66.0, 21.6 μg/adult for T. castaneum). Bornyl acetate and camphene showed moderate repellent effect on T. castaneum and conversely showed attractant effect on L. bostrychophila. This work highlights the insecticidal potential of V. officinalis, which has been noted as a traditional medicinal plant.

[Contrastive analysis of ultrasonographic features of synchronous and heterochronic liver metastasis in patients with stromal tumor]

Objective: To investigate the ultrasonographic features of synchronous and heterochronic liver metastasis in patients with stromal tumors, and to elucidate the value of ultrasonic examination in follow-up surgery. Methods: A total of 1 516 patients with pathologically confirmed gastrointestinal stromal tumors (GISTs) and extra-gastrointestinal stromal tumors (EGISTs) were enrolled. The ultrasonographic features of primary lesions and liver metastases in a total of 46 cases with 95 liver metastases were analyzed. Results: 24 out of 46 cases had primary lesion in the small intestine, 14 in the stomach, 4 in the abdominal cavity, 1 in the colon, 2 in the esophagus, and 1 in the mesentery. The expression of CD117, Dog-1 and CD34were detected by immunohistochemical staining. The positive rate of CD117 was 100%, the Dog-1 was 95.7% and the CD34 was 69.6%. There were statistically significant differences in the maximum diameter, boundary and blood flow of primary tumors in 28 patients with synchronous liver metastasis and 18 patients with heterochronic liver metastasis (P=0.001, 0.022 and 0.036, respectively). Of the 95 liver metastases, 86 (90.5%) were located in the right lobe of the liver, 79 (83.2%) had clear boundaries, 75 (78.9%) were hypoechoic or isoechoic, 55 (57.9%) showed colored patterns, and 68 (71.6%) had no halo.11 liver metastases were cystic masses, 59 were solid masses, and 25 were mixed masses. There was a statistically significant difference in blood flow between 65 synchronous hepatic metastases and 30 heterochronic liver metastases (P=0.017). Conclusions: There were differences of the primary tumor ultrasonographic features between the synchronous metastasis group and heterochronic metastasis group. The ultrasonographic features of primary tumors and liver metastases have important clinical significance for the diagnosis, follow-up and treatment of malignant mesenchymal tumors.

A Ropivacaine-Lidocaine Combination for Caudal Blockade in Haemorrhoidectomy

A single dose of caudal lidocaine does not provide a sufficiently long anaesthetic duration and is not generally used for complicated anorectal surgery. This study evaluated the safety and efficacy of a ropivacaine–lidocaine combination for caudal anaesthesia in patients undergoing haemorrhoidectomy. A total of 287 haemorrhoid patients with successful initial caudal anaesthesia were randomized to receive either a mixture of 0.375% ropivacaine and 1.0% lidocaine (ropi–lido group; n = 146) or 1.0% lidocaine alone (placebo-lido group; n = 141). Significantly fewer patients in the ropi–lido group required intra-operative supplemental anaesthesia than in the placebo-lido group. Patients treated with the ropivacaine–lidocaine combination had significantly lower scores for pain at each post-operative time point, and a longer mean time to the first requirement for post-operative analgesic than patients in the placebo-lido group. These results suggest that caudal anaesthesia with a combination of ropivacaine and lidocaine is a safe and effective method of inducing anaesthesia during haemorrhoidectomy.

Serum- and glucocorticoid-dependent kinase, cell volume, and the regulation of epithelial transport

Ample pharmacological evidence points to a role of kinases in the regulation of cell volume. Given the limited selectivity of most inhibitors, however, the specific molecules involved have remained largely elusive. The search for cell volume regulated genes in liver HepG2 cells led to the discovery of the human serum- and glucocorticoid-dependent serine/threonine kinase hsgk1. Transcription and expression of hsgk1 is markedly and rapidly upregulated by osmotic and isotonic cell shrinkage. The effect of osmotic cell shrinkage on hsgk1 is mediated by p38 kinase. Further stimuli of hsgk1 transcription include glucocorticoids, aldosterone, TGF-beta1, serum, increase of intracellular Ca2+ and phorbolesters, whereas cAMP downregulates hsgk1 transcription. The hsgk1 protein is expressed in several epithelial tissues including human pancreas, intestine, kidney, and shark rectal gland. Co-expression of hsgk1 with the renal epithelial Na+-channel ENaC or the Na+/K+/2Cl(-)-cotransporter NKCC2 (BSC1) in Xenopus oocytes, accelerates insertion of the transport proteins into the cell membrane and thus, stimulates channel or transport activity. Thus, hsgk1 participates in the regulation of transport by steroids and secretagogues increasing intracellular Ca2+-activity. The stimulation of hsgk1 transcription by TGF-beta1 may further bear pathophysiological relevance.

The genomic RNA in Ty1 virus-like particles is dimeric

The yeast retrotransposon Ty1 resembles retroviruses in a number of important respects but also shows several fundamental differences from them. We now report that, as in retroviruses, the genomic RNA in Ty1 virus-like particles is dimeric. The Ty1 dimers also resemble retroviral dimers in that they are stabilized during the proteolytic maturation of the particle. The stabilization of the dimer suggests that one of the cleavage products of TyA1 possesses nucleic acid chaperone activity.

The human immunodeficiency virus type 1 Gag polyprotein has nucleic acid chaperone activity: possible role in dimerization of genomic RNA and placement of tRNA on the primer binding site

The formation of an infectious retrovirus particle requires several RNA-RNA interaction events. In particular, the genomic RNA molecules form a dimeric structure, and a cellular tRNA molecule is annealed to an 18-base complementary region (the primer binding site, or PBS) on the genomic RNA, where it will serve as primer for reverse transcription. tRNAs normally possess a highly stable secondary and tertiary structure; it seems unlikely that annealing of a tRNA molecule to the PBS, which involves unwinding of this structure, could occur efficiently at physiological temperatures without the assistance of a cofactor. Many prior studies have shown that the viral nucleocapsid (NC) protein can act as a nucleic acid chaperone (i.e., facilitate annealing events between nucleic acids), and the assays used to demonstrate this activity include its ability to catalyze dimerization of transcripts representing retroviral genomes and the annealing of tRNA to the PBS in vitro. However, mature NC is not required for these events in vivo, since protease-deficient viral mutants, in which NC is not cleaved from the parental Gag polyprotein, are known to contain dimeric RNAs with tRNA annealed to the PBS. In the present experiments, we have tested recombinant human immunodeficiency virus type 1 Gag polyprotein for nucleic acid chaperone activity. The protein was positive by all of our assays, including the ability to stimulate dimerization and to anneal tRNA to the PBS in vitro. In quantitative experiments, its activity was approximately equivalent on a molar basis to that of NC. Based on these results, we suggest that the Gag polyprotein (presumably by its NC domain) catalyzes the annealing of tRNA to the PBS during (or before) retrovirus assembly in vivo.

HIV-1 nucleocapsid protein induces "maturation" of dimeric retroviral RNA in vitro

After a retrovirus particle is released from the cell, the dimeric genomic RNA undergoes a change in conformation. We have previously proposed that this change, termed maturation of the dimer, is due to the action of nucleocapsid (NC) protein on the RNA within the virus particle. We now report that treatment of a 345-base synthetic fragment of Harvey sarcoma virus RNA with recombinant or synthetic HIV-1 NC protein converts a less stable form of dimeric RNA to a more stable form. This phenomenon thus appears to reproduce the maturation of dimeric retroviral RNA in a completely defined system in vitro. To our knowledge, maturation of dimeric RNA within a retrovirus particle is the first example of action of an "RNA chaperone" protein in vivo. Studies with mutant NC proteins suggest that the activity depends upon basic amino acid residues flanking the N-terminal zinc finger and upon residues within the N-terminal finger, including an aromatic amino acid, but do not require the zinc finger structures themselves.

Multiple regions of Harvey sarcoma virus RNA can dimerize in vitro

Retroviruses contain a dimeric RNA consisting of two identical molecules of plus-strand genomic RNA. The structure of the linkage between the two monomers is not known, but they are believed to be joined near their 5' ends. Darlix and coworkers have reported that transcripts of retroviral RNA sequences can dimerize spontaneously in vitro (see, for example, E. Bieth, C. Gabus, and J. L. Darlix, Nucleic Acids Res. 18:119-127, 1990). As one approach to identification of sequences which might participate in the linkage, we have mapped sequences derived from the 5' 378 bases of Harvey sarcoma virus (HaSV) RNA which can dimerize in vitro. We found that at least three distinct regions, consisting of nucleotides 37 to 229, 205 to 272, and 271 to 378, can form these dimers. Two of these regions contain nucleotides 205 to 226; computer analysis suggests that this region can form a stem-loop with an inverted repeat in the loop. We propose that this hypothetical structure is involved in dimer formation by these two transcripts. We also compared the thermal stabilities of each of these dimers with that of HaSV viral RNA. Dimers of nucleotides 37 to 229 and 205 to 272 both exhibited melting temperatures near that of viral RNA, while dimers of nucleotides 271 to 378 are quite unstable. We also found that dimers of nucleotides 37 to 378 formed at 37 degrees C are less thermostable than dimers of the same RNA formed at 55 degrees C. It seems possible that bases from all of these regions participate in the dimer linkage present in viral RNA.

[Comparison of morphological and microscopical diagnostic characters of Hawthorn fruits (Crataegus species)]

This paper deals with studies on morphological and microscopical diagnostic characters of Chinese Hawthorn fruits. Their similarities and differences in morphological and microscopical characters among eight species of Crataegus (C. pinnatifida Bge., C. pinnatifida var. major NE Br., C. cuneata sieb. & Zuce., C. scabrifolia (Franch.) Rehd., C. hupehensis Sarg., C. kansuensis Wils, C. maximowiczii Schneid. and C. sanguinea Pall.) fruits are compared and illustrated with diagrams.

[Suppressive effects of adenosine on nonspecific and humoral immunities in mice]

Adenosine (Ade) 1.3, 13, 130 mg.kg-1 ip inhibited the ability of peripheral leukocytes and peritoneal macrophages in phagocytosing the Staphylococcus albus with [3H]TdR incorporation in mice, declined the hemolytic ability of plaque-forming cells and the production of antibody in mice immunized by sheep erythrocytes. Ade 13, 130 mg.kg-1 ip decreased the mouse serum muramidase (lysozyme) concentration. Dipyridamole (Dip) 10 mg.kg-1 ip attenuated the effects of Ade 130 mg.kg-1 on humoral immunity reaction, but the nonspecific immunity was not attenuated. These results showed that the uptake of Ade may play an important role in the effects of Ade on humoral immunity reaction. Aminophylline (Ami) 100 mg.kg-1 ip attenuated the effects of Ade 130 mg.kg-1 on hemolytic ability of plaque-forming cells and the ability of peripheral leukocytes in phagocytosing Staphylococcus albus. These results suggested that the effects of Ade on murine humoral and nonspecific immunity reaction were mediated by Ade A2 receptor (A2DR).

[A clinical and basic study on the relationship between acute myocardial infarction and endothelin]

The level of plasma endothelin (ET) was studied in 40 cases with acute myocardial infarction (AMI) with radioimmunoassay. The results showed that plasma ET level reached its peak value (46.01 +/- 1.64 pg/ml) immediately after AMI attack and dropped down (39.37 +/- 0.47 pg/ml) on the first day; The value was still high (15.56 +/- 1.40 pg/ml) on the twenty-eight day: this was significant higher than that in control group (6.35 +/- 0.44 pg/ml, P < 0.001). It was found that height of plasma ET level was closely correlated with severity of myocardial damage and degree of cardiac insufficiency. In order to evaluate the pathogenic role of ET in AMI, the effect of ET-antiserum on myocardial infarction (MI) was investigated on infarct model produced by ligature of left anterior descending coronary artery in rats. The results showed that plasma ET levels elevated significantly in rats with MI (8.4 +/- 1.0, sham 3.1 +/- 0.2 pg/ml, P < 0.01) and ET-antiserum administration dramatically decreased plasma ET level 65% (P < 0.01), lowered plasma content of lipid peroxide 27% (P < 0.01) and reduced infarct size 48% (P < 0.01). It is suggested that ET is an important factor which contributes to the pathogenesis of MI. Limb ischemia and reperfusion study was carried out in rats also. Metallothionein (MT) was found to antagonize markedly ET-induced vasoconstriction and lower the release of ET stimulated by angiotensin II in a dose-dependent manner. It is suggested that under certain pathological conditions MT may exert its injury--resistant and cell protective action.

[Constituents in volatile oil of peilan and 3 plants of the same genus]

A study hes been made on the essential oil from the crude drug Peilan (Eupatorium fortunei) and the plants E. japonicum, E. chinense and E. cannabinum. 71 constituents have been identified by GC-MS. Quantitative analysis has been carried out by GC. The study provides scientific methods for the identification of the crude drug "Peilan" and the quality control of the fresh and dried "Peilan".

Surgical treatment of atherosclerotic infrarenal abdominal aortic aneurysms. A review of 30 years' experience

During the 30 years from 1960 to 1989, 100 sequential patients with atherosclerotic infrarenal abdominal aortic aneurysm (AAA) were admitted to Zhongshan Hospital. Twenty-eight were not treated surgically and 72 underwent resection of the AAA with prosthesis replacement. Nineteen non-surgical patient were followed up, and 8 died from ruptures with a five-year survival rate of 41.3 +/- 13%. In 72 surgically treated patients, the operative mortality was 2.8%. The five-year survival rate is 77.5 +/- 6.2%, which is higher in comparison with the non-surgical group (P < 0.01). The data show that the operation for AAA is safe and the postoperative long-term results are satisfactory.

Bipartite signal for read-through suppression in murine leukemia virus mRNA: an eight-nucleotide purine-rich sequence immediately downstream of the gag termination codon followed by an RNA pseudoknot

The pol gene of murine leukemia virus and other mammalian type C retroviruses is expressed by read-through suppression of an in-frame UAG codon which separates the gag and pol coding regions. In this study, we have analyzed the sequence requirements for read-through suppression by placing different portions of wild-type and mutant viral sequences from the gag-pol junction between reporter genes and testing transcripts of these constructs for suppression in reticulocyte lysates. We find that the read-through signal is contained within the first 57 nucleotides on the 3' side of the UAG codon. Our results indicate that the identities of six conserved bases in the eight-nucleotide, purine-rich sequence immediately downstream of the UAG codon are critical for suppression, as is the existence of a pseudoknot structure spanning the next 49 nucleotides. Thus, read-through suppression depends on a complex, bipartite signal in the mRNA.

Identification of amino acids inserted during suppression of UAA and UGA termination codons at the gag-pol junction of Moloney murine leukemia virus

Expression of the murine leukemia virus pol gene occurs by translational readthrough of an in-frame UAG codon between the gag and pol coding regions. In a previous study, we mutated the UAG codon to UAA or UGA and demonstrated that both of these termination codons could be suppressed in reticulocyte lysates and in infected cells with the same efficiency as UAG. We now report the identity of the amino acids inserted in vitro in response to UAA and UGA in fusion products containing the gag-pol junction region. The results show that UAA, like UAG, directs the incorporation of glutamine, whereas UGA directs the incorporation of three amino acids, arginine, cysteine, and tryptophan. To our knowledge, this is the first report indicating misreading of UAA as glutamine and UGA as arginine and cysteine in higher eukaryotes. Interestingly, although our protein synthesis system presumably contains other known UAG and UGA suppressors, these tRNAs did not suppress the termination codons in our experiments. Thus, it seems possible that the sequence surrounding the gag-pol junction not only promotes suppression but also helps determine which tRNAs function in suppression.

Chromatographic analysis of the aminoacyl-tRNAs which are required for translation of codons at and around the ribosomal frameshift sites of HIV, HTLV-1, and BLV

An examination of the frameshift signals or proposed signals within published sequences of retroviruses and other genetic elements from higher animals shows that each site utilizes a tRNA which normally contains Wybutoxine (Wye) base or Queuine (Q) base in the anticodon loop. We find experimentally that most of the Phe-tRNA present in HIV-1 infected cells lacks the highly modified Wye base in its anticodon loop and most of the Asn-tRNA in HTLV-1 and BLV infected cells lacks the highly modified Q base in its anticodon loop. Interestingly, Phe-tRNA translates a UUU codon within the ribosomal frameshift signal in HIV and Asn-tRNA translates a AAC codon within the proposed frameshift signals in HTLV-1 and BLV. Thus, the lack of a highly modified base in the anticodon loop of tRNAs in retroviral infected cells is correlated with the participation of these undermodified tRNAs in the corresponding frameshift event. This suggests that the "shifty" tRNAs proposed by Jacks et al. (Cell 55, 447-458, 1988) to carry out frameshifting may be hypomodified isoacceptors.

Suppression of UAA and UGA termination codons in mutant murine leukemia viruses

Genomes of mammalian type C retroviruses contain a UAG termination codon between the gag and pol coding regions. The pol region is expressed in the form of a gag-pol fusion protein following readthrough suppression of the UAG codon. We have used oligonucleotide-directed mutagenesis to change the UAG in Moloney murine leukemia virus to UAA or UGA. These alternate termination codons were also suppressed, both in infected cells and in reticulocyte lysates. Thus, the signal or context inducing suppression of UAG in wild-type Moloney murine leukemia virus is also effective with UAA and UGA. Further, mammalian cells and cell extracts contain tRNAs capable of translating UAA and UGA as amino acids. To our knowledge, this is the first example of natural suppression of UAA in higher eucaryotes.

Translational readthrough of the murine leukemia virus gag gene amber codon does not require virus-induced alteration of tRNA

An in vitro system to assay translational readthrough of the UAG termination codon at the murine leukemia virus (MuLV) gag-pol junction was developed by using rabbit reticulocyte lysates programmed by SP6-generated Moloney MuLV gag-pol mRNA. Under conditions in which the suppressor activity of the lysate was dependent on addition of tRNA, it could be shown that readthrough synthesis was stimulated to approximately the same extent by equivalent amounts of tRNA from MuLV-infected and uninfected NIH 3T3 cells. Analysis of glutamine tRNA, which mediates suppression in vivo, showed that the level of glutamine acceptor activity and the chromatographic profile of glutamine isoacceptors were unchanged following virus infection. On the basis of these results, we conclude that the suppressor tRNA occurs normally within the tRNA population of uninfected cells and need not be induced in response to virus infection.

Transcriptional regulation of carnitine palmitoyltransferase synthesis in riboflavin deficiency in rats

Riboflavin deficiency leads to depressed mitochondrial fatty acid oxidation rates but increased activity of carnitine palmitoyltransferase (CPT). Starvation leads to increased CPT activity in ad libitum-fed, riboflavin-supplemented rats. The present studies examined the mechanism of the increase in CPT activity in riboflavin deficiency and whether it was additive to that seen in starvation. Rats were divided into three groups initially: riboflavin-sufficient, ad libitum-fed; riboflavin-deficient, ad libitum-fed; and pair-fed. These groups were subdivided after 5 wk into fed and 24- and 48-h starved groups. When riboflavin-deficient rats were starved for 24 or 48 h, there was only a 30-40% increase in hepatic CPT activity, in contrast to the ad libitum-fed, riboflavin-supplemented rats, in which activity increased twofold. CPT activity of pair-fed rats was similar to that of controls in the fed state and did not increase significantly with starvation. CPT translation, mRNA levels and transcription rates correlated with CPT activity, as did immunoreactive CPT. Concurrently, hepatic ketone production and plasma beta-hydroxybutyrate concentration increased during starvation in the control and pair-fed but not in the riboflavin-deficient rats. The results indicate that increased CPT activity in riboflavin deficiency and starvation results at least in part from increased synthesis. Furthermore, the data support previous work suggesting that the block in fatty acid oxidation occurs in the beta-oxidation pathway at the level of acyl-CoA dehydrogenases.

A simple and rapid solid-phase RNA sequencing method

A simple and rapid solid-phase RNA sequencing method has been developed based on Peattie's direct chemical method. 3'-Terminally labeled RNA was immobilized on DEAE-cellulose sheets and followed by specific modification with dimethyl sulfate, diethylpyrocarbonate, hydroxylamine (at pH 10 for the uridine and pH 5.5 for the cytidine reaction), and cleavage reaction with aniline. RNA fragments were washed from the DEAE-cellulose sheets using salt solutions, precipitated with ethanol, and separated by 15% polyacrylamide gel electrophoresis. Due to the complete removal of the impurities normally present in the solution method, the higher resolution of the sequencing bands and lower background on the autoradiograph make this solid-phase technique more efficient. This solid-phase technique is much faster and more convenient than the original method.

Exceptionally high and diverse mutation rates in insects small rRNA

The nucleotide sequence of 5S rRNA from the posterior silk gland of the silk worm Philosamia cynthia ricini has been determined. The comparison with other insect 5S rRNAs revealed an exceptionally conserved secondary structure, in spite of an extremely high mutation rate: Thirteen nucleotides are different in Philosamia and Drosophila 5S rRNA, but all substitutions are either compensatory or occur in loops or introduce G:U base pairs. The rates of base substitution per site per year of several insect species (diptera and lepidoptera) 5S and 5.8S rRNAs are compared with those occurring in vertebrate rRNAs. In the latter cases the rates are remarkably constant, whereas their value is not only about twofold higher in insect rRNAs, but is found to be extremely large in the 5S rRNA of the silkworm Bombyx mori. These data demonstrate that phylogenetic conclusions derived from small rRNA sequence comparisons are only of limited value.

The nucleotide sequence of 5.8S rRNA from the posterior silk gland of the silkworm Philosamia cynthia ricini

The nucleotide sequence of 5.8S rRNA from the Chinese silkworm Philosamia cynthia ricini has been determined by gel sequencing and mobility shift methods. The complete primary structure is (sequence in text). This is one of the largest known 5.8S rRNAs. As compared to Bombyx 5.8S rRNA, it is two nucleotides longer; two nucleotides near the 5'end and two nucleotides near the 3'end are different, and psi 61 of the Bombyx RNA sequence is an unmodified U in Philosamia RNA. The secondary structure of Philosamia 5.8S rRNA may differ from the Bombyx RNA structure by three additional base pairs at the 5'/3' ends.