Sustainable governance of drinking water conservation areas based on adaptive thresholds

Drinking water quality is integral to the Sustainable Development Goals framework. At the present, China's drinking water conservation faces a number of challenges that are partially brought on by strict conservation measures that don't fully take into account human-land conflict and sustainable development. Taking the idea of adaptive governance, this study seeks to identify adaptive thresholds and adaptive solutions for compatible drinking water conservation and local development. Pressure and resistance to drinking water quality in its status, future potential, and adaptive thresholds were explored to identify sustainable governance for the Baimei Conservation Area, Fujian Province. Field research, local governance forums, and the Soil and Water Assessment Tool (SWAT) model were utilized to explore the drinking water quality pressure and resistance to drinking water quality. In order to uncover potential future changes in pressure and resistance, suitability analyses and multi-scenario simulations were used to examine the status quo, pressure, and resistance scenarios. Adaptive thresholds were then identified through SWAT modeling of each scenario to guarantee the drinking water quality is greater than Class II in the Core Conservation Area and Class Ⅲ in 2nd-grade Conservation Area, respectively. The research finds that construction land development and farming are the key pressures on drinking water quality, and forests and wetlands are the primary resistances. The expansion of construction lands and the increased wetlands was centered on potential future scenarios because farming has no room for growth and forests are already heavily covered. The adaptive threshold of construction land expansion is identified to be 10% without new wetlands but can be 20% by adding 10% wetlands in subbasins, 5, 8, and 9. This study confirms the potential of adaptive sustainability for drinking water conservation areas. A similar analysis procedure can also be adapted to enhance adaptive governance for the sustainability of other conservation areas nationally and globally.

[Prognostic value of the Second Revision of the International Staging System in patients with newly diagnosed transplant-eligible multiple myeloma]

Objective: To verify the predictive value of the Second Revision of the International Staging System (R2-ISS) in newly diagnosed patients with multiple myeloma (MM) who underwent first-line autologous hematopoietic stem cell transplantation (ASCT) in a new drug era in China. Methods: This multicenter retrospective cohort study enrolled patients with newly diagnosed MM from three centers in China (Beijing Chao-Yang Hospital, Capital Medical University; the First Affiliated Hospital, Sun Yat-Sen University, and the Second Affiliated Hospital of Naval Medical University) from June 2008 to June 2018. A total of 401 newly diagnosed patients with MM who were candidates for ASCT were enrolled in this cohort, all received proteasome inhibitor and/or immunomodulator-based induction chemotherapy followed by ASCT. Baseline and follow-up data were collected. The patients were regrouped using R2-ISS. Progression-free survival (PFS) and overall survival (OS) were analyzed. The Kaplan-Meier method was used to analyze the survival curve and two survival curves were compared using the log-rank test. Cox regression analysis were performed to analyze the relationship between risk factors and survival. Results: The median age of the patients was 53 years (range 25-69 years) and 59.5% (240 cases) were men. Newly diagnosed patients with renal impairment accounted for 11.5% (46 cases). According to Revised-International Staging System (R-ISS), 74 patients (18.5 %) were diagnosed with stage Ⅰ, 259 patients (64.6%) with stage Ⅱ, and 68 patients (17.0%) with stage Ⅲ. According to the R2-ISS, the distribution of patients in each group was as follows: 50 patients (12.5%) in stage Ⅰ, 95 patients (23.7%) in stage Ⅱ, 206 patients (51.4%) in stage Ⅲ, and 50 patients (12.5%) in stage Ⅳ. The median follow-up time was 35.9 months (range, 6-119 months). According to the R2-ISS stage, the median PFS in each group was: 75.3 months for stage Ⅰ; 62.0 months for stage Ⅱ, 39.2 months for stage Ⅲ, and 30.3 months for stage Ⅳ; and the median OS was not reached, 86.6 months, 71.6 months, and 38.5 months, respectively. There were statistically significant differences in PFS and OS between different groups (both P<0.001). Multivariate Cox regression analysis showed that stages Ⅲ and Ⅳ of the R2-ISS were independent prognostic factors for PFS (HR=2.37, 95%CI 1.30-4.30; HR=4.50, 95%CI 2.35-9.01) and OS (HR=4.20, 95%CI 1.50-11.80; HR=9.53, 95%CI 3.21-28.29). Conclusions: The R2-ISS has significant predictive value for PFS and OS for transplant-eligible patients with MM in the new drug era. However, the universality of the R2-ISS still needs to be further verified in different populations.

[Research advances on the application of free flaps in repairing diabetic foot ulcers]

Free flaps have been successfully used in the repair of diabetic foot ulcers (DFUs), which can reduce amputation rate, maintain normal gait of patients, and improve life quality of patients. However, there are still many challenges in the repair of DFUs with free flaps, and many problems need to be solved. This paper summarizes the selection of patients, preoperative cautions, types of flaps, methods of vascular anastomosis, clinical effects, and existing problems in using free skin flaps for repairing DFUs.

[Discussion on surgical treatment mode of diabetic foot wounds]

Diabetic foot wounds have a high incidence and uneven therapeutic effect, so it is necessary to explore the suitable treatment mode of diabetic foot wounds. The existing surgical treatment modes for diabetic foot wounds include the multi-disciplinary team (MDT) cooperation mode and the "five-in-one comprehensive limb salvage" treatment mode. These two modes have their own advantages, but are inconvenient to some extent. In response to this problem, the author's team proposed the wound surgical integrated treatment (WSIT) mode based on years of experience in repairing diabetic foot wounds, emphasizing the perioperative management by MDT, and the local wound management by WSIT team, which significantly improved the diagnosis and treatment efficiency of patients with diabetic foot wounds.

A Review of the Phytochemistry and Pharmacology of the Fruit of Siraitia grosvenorii (Swingle): A Traditional Chinese Medicinal Food

Siraitia grosvenorii (Swingle) C. Jeffrey ex Lu et Z. Y. Zhang is a unique economic and medicinal plant of Cucurbitaceae in Southern China. For hundreds of years, Chinese people have used the fruit of S. grosvenorii as an excellent natural sweetener and traditional medicine for lung congestion, sore throat, and constipation. It is one of the first species in China to be classified as a medicinal food homology, which has received considerable attention as a natural product with high development potential. Various natural products, such as triterpenoids, flavonoids, amino acids, and lignans, have been released from this plant by previous phytochemical studies. Phar- macological research of the fruits of S. grosvenorii has attracted extensive attention, and an increasing number of extracts and compounds have been demonstrated to have antitussive, expectorant, antiasthmatic, antioxidant, hypoglycemic, immunologic, hepatoprotective, antibacte- rial, and other activities. In this review, based on a large number of previous studies, we summarized the related research progress of the chemical components and pharmacological effects of S. grosvenorii, which provides theoretical support for further investigation of its biological functions and potential clinical applications.

Anti-RAFLS Triterpenoids and Hepatoprotective Lignans From the Leaves of Tujia Ethnomedicine Kadsura heteroclita (Xuetong)

A pair of 3,4-seco-cycloartane triterpenoid isomers with a rare peroxy bridge, namely, xuetonins A and B (1 and 2), four new lignans xuetonlignans A–D (3–6), a new sesquiterpene xuetonpene (7), and a new natural product xuetonin C (8), along with 43 known compounds, were obtained from the leaves of Tujia ethnomedicine, Kadsura heteroclita. Their structures and configurations were determined with the help of a combination of 1D- and 2D-NMR, HRESIMS spectra, electronic circular dichroism (ECD), and X-ray diffraction data. Compounds 2, 10, 13–15, and 17–19 showed moderate-to-potent activity against rheumatoid arthritis fibroblast-like synoviocytes (RAFLS) with IC₅₀ values of 19.81 ± 0.26, 12.73 ± 0.29, 5.70 ± 0.24, 9.25 ± 0.79, 5.66 ± 0.52, 11.91 ± 0.44, 13.22 ± 0.27, and 15.94 ± 0.36 μM, respectively. Furthermore, compounds 22, 25, and 31 exhibited significant hepatoprotective effects against N-acetyl-p-aminophenol (APAP)–induced toxicity in HepG2 cells at 10 μM, and the cell viability increased by 12.93, 25.23, and 13.91%, respectively, compared with that in the model group (cf. bicyclol, 12.60%).

Cyclocarya paliurus (Batalin) Iljinskaja: Botany, Ethnopharmacology, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Cyclocarya paliurus (Batalin) Iljinskaja (C. paliurus) also known as Sweet tea tree, Money tree, Money willow, green money plum, mountain willow and shanhua tree, is a native rare monocotyledonous plant in Southern China. It possesses numerous traditional benefits, including clearing heat, detoxification, producing saliva, slake thirst, anti-inflammatory, insecticidal, dispelling wind and relieving itching. It is also effective in preventing and treating diabetes, hypertension, hyperlipidemia, dizziness and swelling and pain, as well as reducing cholesterol, and modulating the functions of the immune system. The stem, leaves and bark of this plant are all medicinal parts, but the leaves have the highest research value.

AIM OF THE STUDY

This article summarized the plant's botanical description, distribution, ethnopharmacology, phytochemical profiles and pharmacological for the first time, to provide possible directions for future development and research in brief.

MATERIAL AND METHODS

The literature for this current manuscript was obtained from reports published from 1992 to May 2021 in diverse databases such as the China Knowledge Resource Integrated databases (CNKI), SciFinder, Google Scholar, Baidu Scholar, Elsevier and Pub-Med. The domestic and foreign references published about C. paliurus over recent years were collected, analyzed and summarized.

RESULTS

The botanical characteristics of the fruits of C. paliurus are unique in having a central nutlet surrounded by a circular wing to distinguish the living genera of Juglandaceae. In traditional medicine, C. paliurus leaves are used by the local people of Southern China to make tea to prevent diabetes. More than 210 compounds have been isolated from C. paliurus. Among them, the characteristic 3,4-seco-dammaranes accounted for the most. Other compounds include dammarane tetracyclic triterpenoids, various pentacyclic triterpenoids, flavonoids, isosclerones, phenolic derivatives and polysaccharides. The plant extracts and compounds have been reported to exert various pharmacological activities, such as anti-hyperglycemic, anti-hyperlipidemic, anti-cancer, cytotoxic, anti-oxidative, anti-inflammatory, hepatoprotective, and anti-microbial activities.

CONCLUSIONS

Comprehensive literature analysis shows that C. paliurus extract and its compounds have a variety of biological activities for the treatment of various diseases. The current modern pharmacology research is mostly related to the records of ethnic pharmacology, mainly in vitro research, relatively few in vivo research. Therefore, future studies should focus on this aspect. In addition, we also would like to recommend further research should concentrate on toxicity studies and quality control of C. paliurus to fill the study gap, as well as to provide theoretical support for the further development of the potential functions and clinical applications of the plant.

Seco-Tetracyclic and Seco-Pentacyclic Triterpenoids from Nature: Phytochemistry, Biological Activity: A Review

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Seco-tetracyclic and seco-pentacyclic triterpenoids are a special class of triterpenoids with ring/rings cleaved on the original skeleton structures. A class of important triterpene derivatives, secotetracyclic and seco-pentacyclic triterpenoids, have long stimulated the interest and attention of botanists and natural products chemists. There is no systematic and comprehensive review for them. This review is focused on the phytochemical investigations and biological activities of seco-tetracyclic and seco-pentacyclic triterpenoids from nature, covering the literature from 2000-2019. This review describes 310 seco-tetracyclic and 139 seco-pentacyclic triterpenoids discovered from 154 species belong to 97 genera, which cover the chemical structures, types, sources, and bioactivities of compounds. The literature from 2000-2019 is reviewed and 208 references are cited.

Sesquiterpenes from Kadsura coccinea attenuate rheumatoid arthritis-related inflammation by inhibiting the NF-κB and JAK2/STAT3 signal pathways

The roots of Kadsura coccinea is commonly used in Tujia ethnomedicine, named "heilaohu", having the effect of treating rheumatic arthritis (RA). Chemical investigation on the ethanol extract of heilaohu led to the isolation of one undescribed cuparane sesquiterpenoid, heilaohusesquiterpenoid A, one undescribed carotane sesquiterpenoids, heilaohusesquiterpenoid B, and eighteen sesquiterpene derivatives. Their structures were subsequently determined based on their 1D and 2D-NMR, HR-ESI-MS, and ECD spectroscopic data. Gaultheriadiolide was the most cytotoxic compound against the proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells with an IC₅₀ value of 9.37 μM. In the same line, nine compounds exhibited significant inhibition effects against TNF-α and IL-6 release in the LPS-induced RAW264.7 cells with IC₅₀ values ranging between 1.03 and 10.99 μM. The potential molecular mechanisms of the active compounds against RA were established through pharmacological network analysis based on the initial screening results. Experimental validation showed that gaultheriadiolide suppressed inflammation by inhibiting the NF-kB and JAK2/STAT3 pathways. This study enriches the structural diversity of sesquiterpenes in K. coccinea and lays a foundation for further anti-RA and anti-inflammatory studies.

[The prognostic relationship between CD56 expression and newly diagnosed multiple myeloma]

Objective: To evaluate the prognostic value of CD56 expression in newly diagnosed MM (NDMM). Methods: A total of 332 NDMM patients were enrolled in Beijing Chaoyang Hospital, Capital Medical University from January 1, 2011 to January 1, 2021, with a median age of 60 years and a male to female ratio of 1.2∶1. CD56 expression on myeloma cells was detected by flow cytometry before induction therapy. Overall survival (OS) and progression-free survival (PFS) data were collected. In order to reduce the confounding factors, the propensity score matching technique was used to match CD56 positive versus negative patients at a ratio of 1∶1. Results: Among 332 patients, CD56 positivity rate was 65.1% (216/332). Patients with CD56 expression had significantly longer median OS (58.4 vs. 43.1 months, P=0.024) and PFS (28.7 vs. 24.1 months, P=0.013) than those with negative CD56. Univariate Cox proportional hazards regression analyses showed that CD56 expression was positively correlated with OS (HR=0.644, 95%CI 0.438-0.947, P=0.025) and a favorable prognostic factor for PFS (HR=0.646, 95%CI 0.457-0.913,P=0.013). The favorable effect of CD56 expression on PFS was confirmed in multivariate analysis (HR=0.705, 95%CI 0.497-0.998, P=0.049), but OS was not affected (P>0.05).In the propensity score matching analysis, 194 patients with 97 in each group were identified. CD56 positivity consistently predicted longer PFS (34.2 vs.25.1 months, P=0.047), but not OS (63.4 vs.43.1 months, P=0.056). Conclusion: These results demonstrate that CD56 expression is a favorable prognostic factor for PFS of newly diagnosed MM patients.

Flavanols from Nature: A Phytochemistry and Biological Activity Review

Flavanols, a common class of secondary plant metabolites, exhibit several beneficial health properties by acting as antioxidant, anticarcinogen, cardioprotective, anti-microbial, anti-viral, and neuroprotective agents. Furthermore, some flavanols are considered functional ingredients in dairy products. Based on their structural features and health-promoting functions, flavanols have gained the attention of pharmacologists and botanists worldwide. This review collects and summarizes 121 flavanols comprising four categories: flavan-3-ols, flavan-4-ols, isoflavan-4-ols, and flavan-3,4-ols. The research of the various structural features and pharmacological activities of flavanols and their derivatives aims to lay the groundwork for subsequent research and expect to provide mentality and inspiration for the research. The current study provides a starting point for further research and development.

The medicinal uses of the genus Bletilla in traditional Chinese medicine: A phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Different orchids are important in traditional medicine, and species belonging to the genus Bletilla are important. Bletilla species have been used for thousands of years in Traditional Chinese Medicine (TCM) for the treatment of several health disorders, such as gastrointestinal disorders, peptic ulcer, lung disorders, and traumatic bleeding etc. AIM OF THIS REVIEW: This review aims to provide a systematic overview and objective analysis of Bletilla species and to find the probable relationship between their traditional use, chemical constituents, and pharmacological activities, while assessing their therapeutic potential in treatment of different human diseases.

MATERIALS AND METHODS

Relevant literatures on Bletilla species have been collected using the keywords "Bletilla", "phytochemistry", and "pharmacology" in scientific databases, such as "PubMed", "Scifinder", "The Plant List", "Elsevier", "China Knowledge Resource Integrated databases (CNKI)", "Google Scholar", "Baidu Scholar", and other literature sources, etc. RESULTS: This review indicates the isolation and identification of over 261 compounds from this genus, till December 2020. These chemical isolates belong to the stilbenes (bibenzyls and phenanthrenes), flavonoids, triterpenoids, steroids, simple phenolics, and glucosyloxybenzyl 2-isobutylmalates classes of compounds. These compounds have been reported to be characteristically distributed in Bletilla striata (Thunb.) Rchb. f. (BS), Bletilla ochracea Schltr. (BO), and Bletilla formosana (Hayata) Schltr. (BF). The crude extracts and pure compounds derived from the three Bletilla species have reportedly exhibited a wide spectrum of in vitro and in vivo pharmacological effects, such as hemostatic, anti-inflammatory, anti-tumor, and anti-microbial activities. As a Traditional Chinese Medicine (TCM), Bletilla species or preparations containing Bletilla species have been used for the treatment of epistaxis, gastrointestinal bleeding, cough and hemoptysis, gastric and duodenal ulcer, and traumatic injuries. Thus, Bletilla species have proven potential both in traditional uses and scientific studies.

CONCLUSIONS

Pharmacological studies have validated the use of Bletilla species in the traditional medicine, especially hemorrhagic diseases. Polysaccharides and stilbenes are the major bioactive chemical constituents of Bletilla genus according to the literatures. However, the mechanism of action of these molecules is yet to be studied. In addition, a detailed comparative analysis of the phytochemistry and biological activities of the three Bletilla species (BS, BO and BF) is highly recommended for understanding their ethnopharmacological uses and applications in clinics. Clinical toxicity tests on BS have been found to be negative, but it can't be used with Aconitum carmichaeli in traditional uses. Furthermore, not many reports are present in the literature regarding the conservation of Bletilla species.

Dibenzocyclooctadiene lignans from Kadsura coccinea alleviate APAP-induced hepatotoxicity via oxidative stress inhibition and activating the Nrf2 pathway in vitro

Phytochemical investigation on the roots of Kadsura coccinea led to the isolation five previously unknown dibenzocyclooctadiene lignans, named heilaohusuins A-E (1-5). Their structures determined by NMR spectroscopy, HR-ESI-MS, and ECD spectra. Hepatoprotection effects of a series of dibenzocyclooctadiene derivatives (1-68) were investigated against acetaminophen (APAP) induced HepG2 cells. Compounds 2, 10, 13, 21, 32, 41, 46, and 49 showed remarkable protective effects, increasing the viabilities to > 52.2% (bicyclol, 52.1 ± 1.3%) at 10 μM. The structure-activity relationships (SAR) for hepatoprotective activity were summarized, according to the activity results of dibenzocyclooctadiene derivatives. Furthermore, we found that one new dibenzocyclooctadiene lignan heilaohusuin B attenuates hepatotoxicity, the mechanism might be closely correlated with oxidative stress inhibition via activating the Nrf2 pathway.

[Autologous stem cell transplantation improve the survival of newly diagnosed multiple myeloma patients]

目的

评估自体造血干细胞移植（auto-HSCT）对初治多发性骨髓瘤（MM）疗效及生存的影响。

方法

回顾性分析2008年10月1日至2019年10月1日243例65岁以下接受auto-HSCT的初治MM患者，同时以同期176例≤65岁适合移植但未进行auto-HSCT的初治MM患者作为对照，评估auto-HSCT对患者疗效及生存的影响。为平衡auto-HSCT和非auto-HSCT患者之间各因素的分布，利用倾向性评分匹配技术按照1∶1比例匹配以减少组间的偏差。

结果

通过倾向性评分匹配分析，共筛选出128例患者（每组64例）。64例患者诱导治疗后接受auto-HSCT，24例（37.5％）获得严格意义的完全缓解（sCR），16例（25.0％）获得完全缓解（CR），15例（23.4％）获得非常好的部分缓解（VGPR），9例（14.1％）获得部分缓解（PR），auto-HSCT组疗效明显优于非auto-HSCT组（P＝0.032）。与非auto-HSCT组相比，auto-HSCT组总生存（OS）和无进展生存（PFS）期明显延长［OS：87.6（95％ CI 57.3～117.9）个月对53.9（95％ CI 36.1～71.7）个月，P＝0.011；PFS：42.2（95％ CI 29.9～54.5）个月对22.4（95％ CI 17.1～27.7）个月，P＝0.007］。多因素分析显示auto-HSCT是OS（HR＝0.448，95％CI 0.260～0.771，P＝0.004）和PFS（HR＝0.446，95％CI 0.280～0.778，P＝0.003）的独立保护因素。

结论

auto-HSCT可改善适合移植初治MM患者的OS和PFS。

A Rapid and Accurate 1HNMR Method for the Identification and Quantification of Major Constituents in Qishen Yiqi Dripping Pills

BACKGROUND

Qishen Yiqi dripping pills (QSYQ), composed of four herbal medicines-Salvia miltiorrhiza, Astragalus membranaceus, Panax notoginseng, and Dalbergiaodorifera-are widely used to treat ischemic cerebrovascular and hemorrhagic cerebrovascular conditions.

OBJECTIVE

In this study, a rapid and accurate proton NMR (1HNMR) spectroscopy method was established to control the quality of QSYQ and ensure their clinical efficacy.

METHOD

Firstly, different types of metabolites were identified based on the proton signal peaks of chemical shifts, coupling constants, and related information provided through two-dimensional NMR spectroscopy. Secondly, a quantitative 1HNMR method was established for the simultaneous determination of major constituents in QSYQ samples. In addition, an HPLC method was performed to verify the results obtained by the quantitative proton NMR (qHNMR)  method.

RESULTS

In the present study, 26 metabolites were identified in the 1HNMR spectra of QSYQ. In addition, a rapid and accruate qHNMR method was established for the simultaneous determination of protocatechualdehyde, rosmarinic acid, danshensu, calycosin-7-O-β-D-glucoside, and ononin in ten batches of QSYQ samples for the first time. Moreover, the proposed qHNMR method and HPLC method were compared using Bland-Altman and plots Passing-Bablok regression, indicating no significant differences and a strong correlation between the two analytical methods.

CONCLUSIONS

This method is an important tool for the identification and quantification of major constituents in QSYQ.

HIGHLIGHTS

Compared with traditional HPLC, the established qHNMR method has the advantages of simple sample preparation, short analysis time, and non-destructive analysis.

Chemistry and Pharmacological Activity of Sesquiterpenoids from the Chrysanthemum Genus

Plants from the Chrysanthemum genus are rich sources of chemical diversity and, in recent years, have been the focus of research on natural products chemistry. Sesquiterpenoids are one of the major classes of chemical constituents reported from this genus. To date, more than 135 sesquiterpenoids have been isolated and identified from the whole genus. These include 26 germacrane-type, 26 eudesmane-type, 64 guaianolide-type, 4 bisabolane-type, and 15 other-type sesquiterpenoids. Pharmacological studies have proven the biological potential of sesquiterpenoids isolated from Chrysanthemum species, reporting anti-inflammatory, antibacterial, antitumor, insecticidal, and antiviral activities for these interesting molecules. In this paper, we provide information on the chemistry and bioactivity of sesquiterpenoids obtained from the Chrysanthemum genus which could be used as the scientific basis for their future development and utilization.

A review of the phytochemistry and pharmacology of Kadsura heteroclita, an important plant in Tujia ethnomedicine

ETHNOPHARMACOLOGICAL RELEVANCE

Kadsura heteroclita (Roxb.) Craib (traditionally known as "Xue Tong") is an important member of the economically and medicinally important plant family Schisandraceae. "Xue Tong" is an imperative ingredient of the Tujia ethnomedicine, traditionally used for the treatment of rheumatoid arthritis (RA), hepatitis, and muscles and joint spasm. The plant is known to be a rich source of lignans and triterpenoids. These classes of natural products have been known to possess various pharmacological activities.

AIM OF REVIEW

This review was motivated by the importance of K. heteroclita in traditional Chinese medicine (TCM). It aims to compile the available information on its botanical distribution and description, traditional uses, phytochemistry, pharmacological activities, toxicity, and quality control to provide a solid base for further research and development.

MATERIALS AND METHODS

Relevant literature was collected by several scientific databases including PubMed, CNKI, Scifinder, The Plant List, Google Scholar, Baidu Scholar, Books (Tujia pharmaceutical records, Guangxi Chinese herbal medicine, Hunan pharmaceutical records and Field identification manual of Chinese herbal medicine) and other literature sources (Flora of China, Pharmacopoeia of the People's Republic of China) which helped in collecting maximum data about the studied species.

RESULTS

Traditional uses of K. heteroclita have proven its medicinal importance, providing a rationale for scientific research. Phytochemical studies on the stem of K. heteroclita resulted in the identification of 187 chemical constituents, among which lignans and triterpenoids are the predominant groups. The isolates and crude extracts have been found to exhibit a wide spectrum of in vivo and in vitro pharmacological activities such as anti-RA, anti-inflammatory and analgesic, hepatoprotection, anti-HIV, anti-cancer and anti-HBV. Schisanlactone E (xuetongsu), a triterpenoid, is one of the major components of K. heteroclita exhibiting anti-cancer, neuroprotective and anti-neuroinflammation activities. Interestingly and luckily, this plant has been found to be safe and non-toxic within the therapeutic dose range.

CONCLUSION

Pharmacological investigations have validated the use of K. heteroclita in traditional Chinese medicine (TCM). Literature review has demonstrated that lignans and triterpenoids are possibly responsible for most of the biological activities exhibited by this plant. To conclude, this plant shows immense potential for the discovery of more potent bioactive secondary metabolites and therefore further phytochemical and biological studies on other parts of K. heteroclita need to be conducted and more compounds need to be tested regarding their biological activities to completely explore its value as a tremendously important medicinal plant species.

Transcriptomic and metabonomic profiling reveal the anti-obesity effects of Chikusetsusaponin V, a compound extracted from Panax japonicus

OBJECTIVES

To explore the in vivo anti-obesity effect of chikusetsusaponin V and explore the underlying mechanism by transcriptomic and metabonomic methods.

METHODS

The physiological parameters of high-fat-diet induced obese mice administered with or without 25 mg/kg and 100 mg/kg of chikusetsusaponin V by gavage for 16 weeks were recorded. In addition, the RNA-sequencing and UHPLC-Q-TOF techniques were applied to obtain the transcriptomic and metabolomic profiling, respectively.

KEY FINDINGS

Chikusetsusaponin V could significantly alleviate the high-fat-diet induced increase in the weight of the whole body and obesity-related organs or tissues, and ameliorate the lipid content in the blood, the lipid accumulation in the livers, as well as the hypertrophy of the fat tissues. Importantly, transcriptomic results revealed that more than 30 genes involved in the pathway which closely associates with obesity, were significantly altered. Moreover, metabolomic data indicated the key differential metabolites enriched in the pathways such as the activated protein kinase signaling pathway which is a vital mediator of obesity and other processes.

CONCLUSIONS

The integrative analysis highlighted that chikusetsusaponin V significantly influenced the activated protein kinase signaling pathway at both transcriptomic and metabolomic levels, thereby exerting anti-obesity effects.

Flavonoid glycosides from the rhizomes of Pronephrium penangianum

Six flavonoid glycosides jixueqisus A-F, together with nine known flavonoids, were isolated from the rhizomes of the fern Pronephrium penangianum. Among them, two red pigments jixueqisus A and B possess the same rare 6,8-dimethyl-2-phenyl-7H-1-benzopyran-7-one skeleton (a long conjugated system). Jixueqisu Cwas a dihydrochalcone glycoside, jixueqisu D was a chalcone glycoside, jixueqisu E was an aurone glycoside, and jixueqisu F was a flavonone glycoside. Interestingly, jixueqisus D-F, (2S)-5,2',5'-trihydroxy-7-methoxyflavanone and 5,2',5'-trihydroxy-7-methoxyflavone possessed a 2,5-dihydroxy substituted benzene ring (B-ring). Their structures were elucidated by various spectroscopic and chemical methods. Furthermore, the plausible biosynthetic pathways of jixueqisus A-F were discussed, respectively. All isolated compounds were evaluated for their activities against the proliferation of MCF-7, HepG-2, HCT-116 and BGC-823 tumor cell lines, four known flavane-4-ol glycosides, abacopterins A and C, eruberin B and triphyllin A, exhibited moderate activities to various cell lines.

The flower head of Chrysanthemum morifolium Ramat. (Juhua): A paradigm of flowers serving as Chinese dietary herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Dietary herbal medicines are widely used for the prevention and treatment of a variety of diseases due to their pharmacological activities in China. Juhua (the flower head of Chrysanthemum morifolium Ramat.), the most representative flower-derived one, which is mainly used for the treatment of respiratory and cardiovascular diseases, shows significant activities, such as antimicrobial, anti-inflammatory, and anticancer, and, neuroprotective, as well as effects on the cardiovascular system.

AIMS OF THIS REVIEW

This review aims to provide an overview of the crucial roles of flowers in Chinese dietary herbal medicine, and the pharmaceutical research progress of Juhua (the paradigm of dietary herbal medicine derived from the flower) including its applications in Traditional Chinese medicine and diet, cultivars, phytochemistry, quality control, pharmacology, and toxicity, along with chrysanthemum breeding and biotechnology.

METHOD

The information associated with Chinese dietary herbal medicine, flower-derived medicine, dietary flower, and pharmaceutical research of Juhua, was collected from government reports, classic books of Traditional Chinese medicine, the thesis of doctors of philosophy and maters, and database including Pubmed, Scifinder, Web of Science, Google Scholar, China National Knowledge Internet; and others.

RESULT

All flower-originated crude medicines recorded in Chinese pharmacopeia and their applications were summarized for the first time in this paper. The edible history and development of flowers in China, the theory of Chinese dietary herbal medicines, as well as flowers serving as dietary herbal medicines, were discussed. Moreover, applications in Traditional Chinese medicine and diet, cultivars, phytochemistry, quality control, pharmacology, and safety evaluation of Juhua, together with chrysanthemum breeding and biotechnology, were summarized in this paper.

CONCLUSION

The theory of dietary herbal medicines, which are an important part of the Traditional Chinese medicine system, has a history of thousands of years. Many herbal flowers, serving as dietary herbal medicines, contribute significantly to the prevention and treatment of a variety of diseases for Chinese people. To better benefit human health, more effective supervision practice for dietary herbal medicines is needed. Although various investigations on Juhua have been done, there is a lack of analytical methods for discrimination of cultivar flowers and identification of authenticity. Research on the major compounds with bioactivities, especially those related to its clinical application or healthcare function, as well as their possible mechanize, need be strengthened. More safety evaluation of Juhua should be carried out. The research limitations Juhua is facing exist in all dietary herbal medicine.

New dibenzocyclooctadiene lignan from stems of Kadsura heteroclita

Kadsura heteroclita Roxb. Craib. (Schisandraceae), is a vine plant mainly distributed in southwest part of China. A new dibenzocyclooctadiene lignan, kadsulignan W (1), along with eleven known lignans (2-12) were isolated from chloroform soluble fraction of stems of Kadsura heteroclita. The structure of new lignan was elucidated by extensive spectroscopic techniques, namely one- and two-dimensional NMR spectroscopy, and HRESI-MS analysis. The absolute configuration of the biphenyl ring in the new dibenzocyclooctadiene lignan was discerned by circular dichroism (CD) spectroscopy. Antioxidative effects of these compounds were evaluated on human isolated neutrophils, and compounds 5, 8, 9, and 10 were found to be strongly active with the IC₅₀ of 36.68, 34.41, 35.97, and 33.65 µM, respectively. Furthermore, compound 8 was also found to be cytotoxic against human gastric cancer cells (BGC 823), and human cervical cancer cell lines (HeLa) with the IC50 values of 11.0, and 23.8 µM, respectively.

Hypomethylation of CTCFL promoters as a noninvasive biomarker in plasma from patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third deadliest cancer in the world with high morbidity and poor prognosis. CTCFL (CCCTC-binding factor like) is a member of the cancer testis antigen (CTA) family with oncogenic properties. To demonstrate whether the hypomethylation of CTCFL promoters in plasma could be used as a noninvasive biomarker to predict poor prognosis of HCC, we extracted cell-free DNA from the plasma and detected the methylation status of CTCFL in 43 HCC, 5 liver cirrhosis and 6 benign lesion samples using methylation specific PCR (MSP). Our study indicated that the hypomethylation of CTCFL promoters in HCC plasma samples (60.4%) was significantly different from that in benign lesion plasma samples (16.7%) with a p-value of 0.043. Analysis of clinicopathological data showed that the methylation status of CTCFL promoters was significantly correlated with microvascular involvement (MVI) (p=0.001) and postoperative recurrence (p=0.031). Furthermore, clinical prognosis data of 347 HCC patients from The Cancer Genome Atlas (TCGA) database displayed that the hypomethylated group had worse overall survival than the hypermethylated group (p=0.0056). In conclusion, we provide evidence that the hypomethylation of CTCFL promoters in cell-free DNA is a biomarker for monitoring HCC patients, which can be used as a noninvasive prediction index for tumor recurrence and provide the individualized decision-making for clinicians.

Xuetonglactones A-F: Highly Oxidized Lanostane and Cycloartane Triterpenoids From Kadsura heteroclita Roxb. Craib

Xuetonglactones A–F (1–6), six unreported highly oxidized lanostane- and cycloartane-type triterpenoids along with 22 known scaffolds (7–28) were isolated from the stems of Kadsura heteroclita (Roxb.) Craib. Compared with previous congeners, xuetonglactone A (1), possesses an unprecedented 20,21-α-epoxide, and xuetonglactone D (4) features an unusual 19-α-hydroperoxyl moiety. The structures and the absolute configurations of the compounds were established by extensive one- and two-dimensional NMR, and electronic circular dichroism (ECD) spectroscopic analysis, with those of 1 and 5 confirmed by single-crystal X-ray diffraction technique. Compounds 1 and 2 exhibited inhibition of iNOS activity in LPS-induced macrophages with IC₅₀ values of 22.0, and 17.0 μg/mL, respectively. While compounds 6, 7, 8, and 24 showed potent cytotoxic activities against human cervical cancer cell lines (HeLa) with the IC₅₀ values of 4.0, 5.8, 5.0, and 6.4 μM, and against human gastric cancer cells (BGC 823) with the IC₅₀ values of 2.0, 5.0, 2.5, and 2.0 μM, respectively. Moreover, plausible biogenetic pathways of (1–6) were also proposed.

Schinortriterpenoids from Tujia ethnomedicine Xuetong-The stems of Kadsura heteroclita

In the present work, we take advantage of the characteristic NMR signal (δ_C-10 = 96.0-99.9) for guiding the isolation of schinortriterpenoids (SNTs) from n-butanol fraction of stems of Kadsura heteroclita which is a Tujia ethnomedicine with trivial name "Xuetong". This effort resulted in the identification of three unreported 3,4:9,10-disecocycloartane triterpenoids xuetongdilactones A-C and three undescribed SNTs xuetongdilactones D-F, along with two known SNTs, namely, wuweizidilactone B and micrandilactone B. The structures of the unreported compounds were established based on 1D, and 2D NMR, HRESIMS, and ECD spectroscopic data analysis. The absolute stereochemistry of xuetongdilactone A was determined by X-ray diffraction analysis along with ECD calculation. The antioxidant and cytotoxic activities were evaluated for all the isolated compounds.

Two new alkaloids isolated from traditional Chinese medicine Binglang the fruit of Areca catechu

Binglang, the fruit of Areca catechu L, has a long history as an important Chinese herbal medicine. Two new alkaloids (1 and 2), along with forty-one known compounds (3-43) were isolated from the dried fruit of Areca catechu L. The structures were elucidated on basis of the IR, UV, MS and 1D, 2D NMR spectroscopic data. Compounds 26 and 33 showed weak cytotoxicity against human gastric cancer cell line (BGC-823) with IC₅₀ of 15.91 μM and 20.13 μM, respectively.

RBC membrane camouflaged prussian blue nanoparticles for gamabutolin loading and combined chemo/photothermal therapy of breast cancer

Due to the non-targeted release of anti-cancer agent gamabufotalin (CS-6), conventional chemotherapy using this drug can cause serious side effects, which accordingly result in poor therapeutic efficiency. Recently, the development of smart nanodrug systems has attracted more and more attention due to their significant advantages of high loading efficiency, controllable release behavior and targeted accumulation at tumor sites. In this study, a nanodrug system named as HA@RBC@PB@CS-6 NPs (HRPC) was constructed. In this system, Prussian blue nanoparticles (PB NPs) with hollow porous structure were used as the carrier for CS-6 and photothermal sensitizer simultaneously. The result indicated that the encapsulation of erythrocyte membrane on the PB NPs prolonged the blood circulation life to 10 h and improved the immune evasion ability for more than 60%, as well, which is beneficial for the targeting molecule (HA) to achieve high concentration accumulation of HRPCs at tumor sites. Moreover, we also disclosed that loading drug of CS-6 performed its ultra-strong anti-tumor function partly through markedly suppressing the expression of HSP70, which conversely amplified the efficiency of photothermal therapy. The in vivo study demonstrated the outstanding performance of HRPC in synergistic photothermal/chemotherapy of cancer without side effect to normal tissues.

Vitamin D-supplemented yogurt drink reduces Candida infections in a paediatric intensive care unit: a randomised, placebo-controlled clinical trial

BACKGROUND

The prevalence of Candida infections in paediatric intensive care units (PICUs) has dramatically increased as a result of resistance to conventional anti-fungal treatments. Because vitamin D has been shown to exhibit fungicidal activity against Candida infection in an in vitro antimicrobial screening, we aimed to investigate the effect of vitamin D on Candida infections in the PICU.

METHODS

Four hundred sixteen eligible children aged between 12 months to 5 years old admitted to the PICU, who were on broad-spectrum antibiotic therapy, participated in the study. Patients were randomly assigned to two study groups, receiving a plain yogurt drink (placebo group) or supplemented with 300 IU day^-1 vitamin D (VD group). Primary outcome was defined as the incidences of Candida colonisation (Candida isolated from rectal swab) 14 days after enrollment. Secondary outcome measures were Candida growth in blood (candidaemia) and urine (candiduria).

RESULTS

The prevalence of candiduria as well as candidaemia was significantly lower in the VD-treated group (26 cases) than in the placebo group (62 cases). The mean (SD) length of PICU stay was obviously lowered in the VD group [11.8 (1.2) days] compared to the placebo group [15.2 (2.3 days)], whereas cases of patient death were similar between the two groups.

CONCLUSIONS

Supplementation of vitamin D effectively reduces infections of Candida in children who were critically ill and on broad-spectrum antibiotic treatment.

Mitochondrial cytochrome P450 (CYP) 1B1 is responsible for melatonin-induced apoptosis in neural cancer cells

Melatonin is an endogenous indoleamine with a wide range of biological functions in the various organisms from bacteria to mammals. Evidence indicates that melatonin facilitates apoptosis in cancer cells and enhances the antitumor activity of chemotherapy in animals and clinical studies. However, the melatonin metabolism and the key metabolic targets in cancer cells still remain unknown. In this study, U118 and SH-SY5Y tumor cell lines were used to investigate the metabolic pathways of melatonin in cancer cells. Interestingly, the inhibitory effect of melatonin on proliferation in SH-SY5Y cells is more potent than that in U118 cells. In contrast, this inhibitory effect on the normal cells is absent. The antitumor effects of melatonin are positively associated with its metabolite N-acetylserotonin (NAS). Unexpectedly, CYP1B1 is, for first time, identified to localize in the mitochondria of tumor cells, and it metabolizes melatonin to form NAS in situ, which subsequently triggers mitochondria-dependent apoptosis in cancer cells. In normal cells, NAS does not induce apoptosis. A remarkable individual variation on CYP1B1 expression was also detected in human tumor tissue. These findings provide the novel mechanisms regarding the antitumor effects of melatonin in the level of mitochondria. Thus, we hypothesize that CYP1B1 overexpression in mitochondria would significantly enhance the antitumor effects of melatonin. Mitochondrial CYP1B1 can potentially serve as a specific target to modify the therapeutic and biological effects of melatonin on cancer patients.

Two new sesquiterpene lactone glycosides from Cnicus benedictus

Two new sesquiterpene lactone glycosides, namely melitensin 15-O-β-D-glucoside (1) and 11β,13-dihydrosalonitenolide 15-O-β-D-glucoside (2), along with eight known compounds (3-10) were isolated from the aerial part of Cnicus benedictus L. Their structures were elucidated from analyses of extensive spectroscopic data. Compounds 1-6 all possessed an α-methyl-γ-lactone moiety. Moreover, compound 5 exhibited moderate activity against the growth of Aspergillus fumigatus, with IC₅₀ values of 17.67 μg mL^-1.

Polyacetylenic Oleanane-Type Triterpene Saponins from the Roots of Panax japonicus

Three new polyacetylenic oleanane-type triterpenoids, baisanqisaponins A-C (1-3), and one new oleanane-type triterpenoid, chikusetsusaponin-V ethyl ester (4), together with 19 known compounds (5-23), were isolated from the roots of Panax japonicus. The structures were elucidated on the basis of spectroscopic analyses and chemical methods. Compounds 1-3 feature a rare panaxytriol group containing a polyacetylene on the saponin skeleton. Neuroprotective activity was evaluated for compounds 1-17, and angiotensin II-induced vascular smooth muscle cell proliferation inhibition was tested for compounds 5-7 and 10-12.

Intractable and dramatic diarrhea in liver transplantation recipient with vasoactive intestinal peptide-producing tumor after split liver transplantation: a case report

Diarrhea after liver transplantation is a common complication. Vasoactive intestinal peptide-producing tumor (VIPoma) is a rare cause of watery diarrhea; 80% of such tumors occur in the pancreas, but it is rare in liver. Hypersecretion of vasoactive intestinal polypeptide can stimulate intestinal water and electrolyte secretion, and patients with VIPoma present with watery diarrhea, hypokalemia, and dehydration. Here we report on a 50-year-old man who presented with a 7-month history of watery diarrhea. He had undergone an orthotopic split-liver transplantation for hepatocellular carcinoma in November 2011. Two months after the liver transplantation, he presented with watery diarrhea, dehydration, and hypokalemia. Antibiotics, immunosuppressive drugs modification, antidiarrheal agents, antispasmodics, adsorbents, and fasting were alternately used to control the diarrhea, but his symptoms remained unchanged. A chromogranin examination, a marker of pancreatic neuroendocrine neoplasm, was positive in the third month of the diarrhea history and VIPoma was considered. Treatment with somatostatin immediately controlled the diarrhea, but the primary lesion could not be identified even after corresponding examinations were completed. In the ninth month of diarrhea, a 1 × 1-cm lesion was detected in the right liver by ultrasonography. Radiofrequency ablation was performed, and the diarrhea stopped. Seventeen months later, the chromogranin level decreased to normal and the patient was asymptomatic. Neither the recipient sharing the other liver portion nor the donor presented with any symptoms, so we wondered how the tumor occurred. It is possible that a small VIPoma lesion existed in the liver donor before the transplantation, and that the immunosuppressive drugs induced tumor development.

Applications of the line-of-response probability density function resolution model in PET list mode reconstruction

Resolution degradation in PET image reconstruction can be caused by inaccurate modeling of the physical factors in the acquisition process. Resolution modeling (RM) is a common technique that takes into account the resolution degrading factors in the system matrix. Our previous work has introduced a probability density function (PDF) method of deriving the resolution kernels from Monte Carlo simulation and parameterizing the LORs to reduce the number of kernels needed for image reconstruction. In addition, LOR-PDF allows different PDFs to be applied to LORs from different crystal layer pairs of the HRRT. In this study, a thorough test was performed with this new model (LOR-PDF) applied to two PET scanners-the HRRT and Focus-220. A more uniform resolution distribution was observed in point source reconstructions by replacing the spatially-invariant kernels with the spatially-variant LOR-PDF. Specifically, from the center to the edge of radial field of view (FOV) of the HRRT, the measured in-plane FWHMs of point sources in a warm background varied slightly from 1.7 mm to 1.9 mm in LOR-PDF reconstructions. In Minihot and contrast phantom reconstructions, LOR-PDF resulted in up to 9% higher contrast at any given noise level than image-space resolution model. LOR-PDF also has the advantage in performing crystal-layer-dependent resolution modeling. The contrast improvement by using LOR-PDF was verified statistically by replicate reconstructions. In addition, [(11)C]AFM rats imaged on the HRRT and [(11)C]PHNO rats imaged on the Focus-220 were utilized to demonstrated the advantage of the new model. Higher contrast between high-uptake regions of only a few millimeter diameter and the background was observed in LOR-PDF reconstruction than in other methods.

Evaluation of bias and variance in low-count OSEM list mode reconstruction

Statistical algorithms have been widely used in PET image reconstruction. The maximum likelihood expectation maximization reconstruction has been shown to produce bias in applications where images are reconstructed from a relatively small number of counts. In this study, image bias and variability in low-count OSEM reconstruction are investigated on images reconstructed with MOLAR (motion-compensation OSEM list-mode algorithm for resolution-recovery reconstruction) platform. A human brain ([(11)C]AFM) and a NEMA phantom are used in the simulation and real experiments respectively, for the HRRT and Biograph mCT. Image reconstructions were repeated with different combinations of subsets and iterations. Regions of interest were defined on low-activity and high-activity regions to evaluate the bias and noise at matched effective iteration numbers (iterations × subsets). Minimal negative biases and no positive biases were found at moderate count levels and less than 5% negative bias was found using extremely low levels of counts (0.2 M NEC). At any given count level, other factors, such as subset numbers and frame-based scatter correction may introduce small biases (1-5%) in the reconstructed images. The observed bias was substantially lower than that reported in the literature, perhaps due to the use of point spread function and/or other implementation methods in MOLAR.

Direct pathogen detection from swab samples using a new high-throughput sequencing technology

The detection of emerging infectious diseases has been a continuing concern, especially with the novel influenza A (H1N1) viral pandemic of 2009. In the present study, we validated a ‘second-generation’ parallel sequencing platform for viral detection in swab samples collected during recent influenza virus infections in Beijing. This operation yielded millions of valid reads per sample and resulted in an almost complete spectrum of nucleotide information. Importantly, novel A (H1N1) and seasonal A (H3N2) influenza virus-derived sequences were detected without prior knowledge or use of genetic information in advance, suggesting that this approach could be a valuable tool for diagnosing emerging infectious diseases.

Synthesis of RGD containing peptides and their vasodilation effect

APLRV, SLRR, RGDS, and RGDF were synthesized by use of the solution method via the corresponding protective intermediates. After fragment condensation and deprotection, APLRVRGDS, APLRVRGDF, SLRRRGDS, and SLRRRGDF were obtained. The effect of these RGD containing peptides on rat aortic strips pretreated with noradrenaline (NE) were observed. The relaxing extents of contracted strips for them at three doses (10(-5) mol/L, 10(-6) mol/L and 10(-7) mol/L) indicated that, in a few cases, this kind of combination of these fragments may enhance the desirable activity.

Development of Female Contraceptive Vaccine Through DNA Inoculation of Human Chorionic Gonadotropin Beta Subunit (hCGß)

Human chorionic gonadotropin (hCG) has been considered as a primary target molecule for a contraceptive vaccine by the World Health Organization because of its physiological and temporal specificity. hCG is an essential factor for the successful implantation and establishment of early pregnancy. For a decade, the most advanced works in development of a contraceptive vaccine have been concentrated on polypeptide based vaccines targeted directly against hCG. Although many studies have reached the stage of clinical testing using a number of prototype vaccines based on different parts of hCG molecule, their efficacy has been disappointing (1-4).

Concordant induction of cyclin E and p21cip1 in differentiated keratinocytes by the human papillomavirus E7 protein inhibits cellular and viral DNA synthesis

Productive infections by human papillomaviruses (HPVs) occur only in differentiated keratinocytes in squamous epithelia in which the HPV E7 protein reactivates the host DNA replication machinery to support viral DNA replication. In a fraction of the differentiated keratinocytes, E7 also posttranscriptionally induces p21Cip1, which is distributed in a mutually exclusive manner with unscheduled cellular DNA synthesis. In this study, double immunofluorescence labeling unexpectedly revealed that E7 caused a concordant accumulation of both cyclin E and p21Cip1 to high levels in patient papillomas and in organotypic cultures of primary human keratinocytes. The induction of cyclin E is mutually exclusive with unscheduled cellular DNA synthesis or abundant viral DNA. These novel virus-host interactions in differentiated keratinocytes are in contrast to previous observations made in submerged proliferating cultures, in which HPV E7 induces cyclin E and overcomes p21Cip1 inhibition of S-phase entry. We propose that an appropriately timed induction of cyclin E/cyclin-dependent kinase 2 by HPV E7 in postmitotic cells enables S-phase reentry and HPV DNA amplification, whereas prematurely induced cyclin E stabilizes p21Cip1 protein, which then inhibits cyclin E/cyclin-dependent kinase 2. Consequently, cyclin E and p21Cip1 both fail to turn over, and DNA synthesis does not occur.

Post-transcriptional induction of p21cip1 protein by human papillomavirus E7 inhibits unscheduled DNA synthesis reactivated in differentiated keratinocytes

Productive infection by human papillomaviruses (HPVs) occurs only in differentiated squamous epithelial cells in papillomas, condylomata, and low grade intraepithelial neoplasias. Host DNA replication is reactivated in a fraction of terminally differentiated keratinocytes in benign human lesions and in organotypic raft cultures of primary human keratinocytes (PHKs) transduced with retroviruses expressing HPV-18 E7 oncogene from its native upstream regulatory region (URR). Thus the natural function of E7 protein, which inactivates pRB family proteins, is to induce host genes essential to support viral DNA replication in post-mitotic cells. Using this raft culture model system, we show that HPV-18 URR-E7 induces the universal cyclin-dependent kinase inhibitor p21cip1 protein in a fraction of differentiated PHKs. Induction is mediated by posttranscriptional mechanisms independent of p53. Double immunofluorescence studies demonstrate that, in raft cultures and in laryngeal papillomas, p21cip1 induction and reactivated host DNA synthesis take place in a mutually exclusive manner in PCNA-positive, differentiated keratinocytes. We suggest that p21cip1 induction effectively blocks unscheduled DNA synthesis reactivated by E7. These results begin to explain the inverse relationship between p21cip1 induction and HPV activities previously observed in a spectrum of benign lesions regardless of HPV types present.