Effects of clonal fragmentation on Pyrrosia nuda depend on growth stages in a rubber plantation

Introduction

Clonal fragmentation helps to assess clonal plants' growth resilience to human and environmental disturbance. Although clonal integration in epiphytes in tropical rubber plantations is important to understand their role in enhancing biodiversity and ecosystem services, research on this subject is limited. These plantations are typically monospecific economic forests that face increased anthropogenic disturbances.

Methods

In this study, we selected the clonal fern Pyrrosia nuda to study its survival status, biomass, maximum quantum yield of photosystem II (Fv/Fm), and frond length in response to the level of clonal fragmentation in a tropical rubber plantation.

Results and discussion

The results showed that (1) clonal fragmentation significantly negatively affected the survival rate, biomass, and frond length of clonal plants, but with minimal effects on Fv/Fm at different growth stages; (2) the performance of a ramet (e.g., biomass or frond length) increased with ramet developmental ages and decreased with the number of ramets in a clonal fragment. The age-dependent impacts of clonal fragmentation provide insights into the biodiversity conservation of epiphytes and forest management in man-made plantations. Therefore, to better conserve the biodiversity in tropical forests, especially in environment-friendly rubber plantations, there is a need to reduce anthropogenic disturbances and alleviate the level of fragmentation.

[The efficacy and safety of immunotherapy combined with chemotherapy neoadjuvant in locally advanced resectable hypopharyngeal squamous cell carcinoma]

Objective: To explore the efficacy and safety of immunoneoadjuvant therapy with pembrolizumab combined with chemotherapy in locally advanced resectable hypopharyngeal squamous cell carcinoma patients. Methods: This study was a prospective, single arm, single center clinical study that was opened for enrollment in April 2021. Patients who met the inclusion criteria at the Cancer Hospital of the Chinese Academy of Medical Sciences were treated with neoadjuvant therapy of pembrolizumab combined with cisplatin and paclitaxel, and after treatments, received surgery and postoperative adjuvant therapy. The main endpoint of this study was postoperative pathological complete response (pCR), and other observations included adverse reactions and long-term prognoses of patients after neoadjuvant therapy. Results: By September 2023, a total of 23 patients who underwent neoadjuvant therapy and surgery were enrolled in the study and all patients were males aged 49-74 years. All patients were locally advanced stage, including 3 patients in stage Ⅲ and 20 patients in stage Ⅳ. There were 12 cases of primary lesions with posterior ring involvement accompanied by fixation of one vocal cord and 20 cases of regional lymph node metastases classified as N2. Eighteen cases received a two cycle regimen and 5 cases received a three cycle regimen for neoadjuvant therapy. The postoperative pCR rate was 26.1% (6/23), with no surgical delay caused by adverse drug reactions. The laryngeal preservation rate was 87.0% (20/23). Pharyngeal fistula was the main surgical complication, with an incidence of 21.7% (5/23). The median follow-up time was 15 months, and 3 patients experienced local recurrence. Conclusions: The immunoneoadjuvant therapy of pembrolizumab combined with chemotherapy has a high pCR rate in locally advanced resectable hypopharyngeal squamous cell carcinoma, with increased laryngeal preservation rate and no significant impact on surgical safety.

[Pembrolizumab plus nab-paclitaxel and platinum as first-line treatment in patients with recurrent or metastatic head and neck squamous-cell carcinoma: a prospective phaseⅡstudy]

Objective: To evaluate the efficacy and safety of pembrolizumab plus nab-paclitaxel and platinum as first-line treatment in patients with recurrent or metastatic head and neck squamous-cell carcinoma (R/M HNSCC). Methods: This was a prospective, single-arm, open label, phase 2 clinical study enrolling patients at the Cancer Hospital of the Chinese Academy of Medical Sciences with R/M HNSCC treated with pembrolizumab plus nab-paclitaxel and cisplatin or carboplatin. After six cycles of treatment, patients received pembrolizumab as maintenance therapy until disease progression or intolerable toxicity or completion of 35 cycles of treatment. The primary endpoint was objective response rate, and secondary endpoints included overall survival, progression-free survival, and safety profile. Efficacy was evaluated according to the response evaluation criteria in solid tumors 1.1, survival analysis was performed using the Kaplan-Meier method, and adverse events were assessed using the America National Cancer Institute Common Terminology Criteria for Adverse Events 5.0. Results: A total of 30 patients with R/M HNSCC were enrolled from 23 April 2021 to 22 March 2023, including 28 males and 2 females, with a median age of 67 years. The median follow-up time was 14.5 months, the objective response rate was 70.0%, the disease control rate was 96.7%, and the median progression-free survival and overall survival of all patients were 11.6 months and 18.8 months, respectively. Median duration of response was up to 17.3 months. Grade≥3 treatment-related adverse events were leukopenia (26.7%), neutropenia (26.7%), peripheral neurotoxicity (3.3%), rash (3.3%), hyperalgesia (3.3%), and immune-related pneumonitis (3.3%). The most common immune-related adverse event was hypothyroidism (40.0%). Conclusion: Pembrolizumab combined with nab-paclitaxel and platinum shows encouraging antitumor activity accompanied with a manageable safety profile in untreated R/M HNSCC patients in China.

[Correlation of MYB/NFIB gene fusion with the grade and prognosis of head and neck adenoid cystic carcinoma and the concordance of two detection methods]

Objective: To explore the correlation between MYB/NFIB gene fusion and clinicopathological features such as tumor grade and prognosis of head and neck adenoid cystic carcinoma (ACC), and to assess the concordant rate of fluorescent in situ hybridization (FISH) with MYB and NFIB immunohistochemistry. Methods: FISH detection of MYB/NFIB gene fusion was performed on 48 head and neck ACC cases and 15 non-ACC salivary gland tumors at National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China during April 2014 and January 2020. ACC cases were divided into grade Ⅰ-Ⅱ, grade Ⅲ and high-grade transformation, according to pathological grading criteria. Prognosis, FISH results and other clinicopathological characteristics were analyzed. MYB and NFIB immunohistochemistry was performed on the 48 ACC and 15 non-ACC cases. The diagnostic accuracy of FISH and immunohistochemistry was compared. Results: FISH detected MYB/NFIB gene fusion in 41.7% (20/48) of the ACC. Its positive rate was inversely correlated with higher pathological grades (P=0.036). The higher histological grade was linked to worse progression-free survival (P=0.024), whereas there was no correlation between the status of gene fusion detected by FISH and progression-free survival (P=0.536). FISH didnot detect MYB/NFIB gene fusion in 15 non-ACC salivary gland tumors The specificity of diagnosing ACC is 100% for both FISH detection of gene fusion and immunohistochemical detection of MYB expression. However, the sensitivity for both methods was only about 41.7%, respectively. By combining FISH and MYB immunohistochemistry, the sensitivity for diagnosing ACC was increased to 66.7%. Conclusions: MYB/NFIB gene fusion has a lower detection rate in grade Ⅲ ACC and high-grade transformation ACC. Meanwhile gene fusion status is not correlated with prognosis. The sensitivity for diagnosing ACC can be improved by combining FISH and MYB immunohistochemistry.

Effects of topography and historical disturbance on canopy height structure of tropical forests in Menglun, Xishuangbanna, China

With the combination of airborne Lidar and panchromatic images in 1981 and 2021, we investigated the canopy height structure of tropical forests in Menglun sub-reserve in the Xishuangbanna National Nature Reserve of Yunnan Province, and analyzed its relationship with environmental factors by using multiple regression tree (MRT) method. The results showed that forests in the Menglun sub-reserve could be clustered into seven types based on canopy height structures, with tropical rainforest, monsoon evergreen broad-leaved forest, secondary forest, and flood plain forest as the main types. The potential solar radiation, altitude, terrain profile curvature, slope and the brightness value of imageries in 1981 and 2021 were main factors that drove the classification. The tropical seasonal rainforest dominated by Pometia pinnata occupied the largest area in valley and low-land. The monsoon evergreen broad-leaved forest dominated by Castanopsis echinocarpa mainly distributed in the ridge and disturbed areas. The secondary forests had homogeneous canopy surface, which was significantly different from the primary forests. The activities of swidden agriculture about three decades ago had legacy impacts on the physiognomy of secondary forests.

Hemiepiphytic figs kill their host trees: acquiring phosphorus is a driving factor

Hemiepiphytic figs killing their host trees is an ecological process unique to the tropics. Yet the benefits and adaptive strategies of their special life history remain poorly understood. We compared leaf phosphorus (P) content data of figs and palms worldwide, and functional traits and substrate P content of hemiepiphytic figs (Ficus tinctoria), their host palm and nonhemiepiphytic conspecifics at different growth stages in a common garden. We found that leaf P content of hemiepiphytic figs and their host palms significantly decreased when they were competing for soil resources, but that of hemiepiphytic figs recovered after host death. P availability in the canopy humus and soil decreased significantly with the growth of hemiepiphytic figs. Functional trait trade-offs of hemiepiphytic figs enabled them to adapt to the P shortage while competing with their hosts. From the common garden to a global scale, the P competition caused by high P demand of figs may be a general phenomenon. Our results suggest that P competition is an important factor causing host death, except for mechanically damaging and shading hosts. Killing hosts benefits hemiepiphytic figs by reducing interspecific P competition and better acquiring P resources in the P-deficient tropics, thereby linking the life history strategy of hemiepiphytic figs to the widespread P shortage in tropical soils.

Contamination and source-specific risk analysis of soil heavy metals in a typical coal industrial city, central China

Source-specific risk apportionment for soil heavy metals (HMs) is crucial for pollution mitigation and risk control in coal-mining areas. The ecological and human health risks resulting from different sources were evaluated through an integrated method that combines risk assessments with positive matrix factorization (PMF) model. Thirty soil samples were collected from a typical coal-mining city in central China and analyzed for six HMs (Cu, Ni, Pb, Cd, As, and Hg). The results indicate that surface soil in the study area suffered from moderate HMs pollution, especially pollution by Cd and Hg. Four potential sources of soil HMs were identified and quantified in the study area, including natural source (27.7%), traffic emissions (33.4%), agricultural practices (16.2%), and industrial activities (22.7%). The ecological risk of the study area was at moderate level, and the leading contributions in urban and suburban areas were from industrial activities and agricultural practices, respectively. The non-carcinogenic risks for adults and children were lower than the risk threshold, while the carcinogenic risks ranged between 1E-06 and 1E-04, suggesting that carcinogenic risks and hazards to human health should not be neglected. Traffic emissions and natural sources mainly contributed to the non-carcinogenic and carcinogenic risks, due to the strong non-carcinogenicity and carcinogenicity of As and Ni. These findings highlight the ecological and health risks linked to potential sources of soil HMs contamination and provide valuable information on the reduction of corresponding risks for local environmental managers.

Urinary biomarkers of early renal injury in antiretroviral-naïve HIV-positive persons in Shanghai, China: comparison with the general population

Objectives

People living with HIV (PLWH) have a high risk of kidney injury. Measurement of serum creatinine, along with proteinuria, is not sensitive to detect early kidney injury. Here, we investigated novel urinary biomarkers of early renal injury in PLWH.

Methods

We performed a cross‐sectional study of 166 antiretroviral‐naïve PLWH and 99 HIV‐negative persons who all had an estimated glomerular filtration rate > 90 mL/min/1.73 m². We compared the levels of seven urinary biomarkers between the two groups using the propensity score matching (PSM) approach and explored the risk factors associated with elevated urinary biomarkers in PLWH.

Results

Eighty‐three pairs were successfully matched based on PSM. Compared with the HIV‐negative group, the HIV‐positive group had higher ratios of N‐acetyl‐β‐D‐glucosaminidase (NAG) to urine creatinine (UCr), alpha1‐microglobulin (α1‐M) to UCr, kidney injury marker‐1 (KIM‐1) to UCr, neutrophil gelatinase‐associated lipocalin to UCr, and epidermal growth factor to UCr, whereas the Tamm–Horsfall protein to UCr ratio and the abnormal albumin to UCr ratio were not significantly different. Positive correlations were observed between HIV RNA level and NAG: UCr (r_s = 0.32; P < 0.001) and α1‐M:UCr (r_s = 0.24; P = 0.002) ratios, and negative correlations were observed between CD4 cell count and NAG:UCr (r_s = –0.34; P < 0.001), KIM‐1:UCr (r_s = –0.16; P = 0.042) and α1‐M:UCr (r_s = –0.36; P < 0.001) ratios. In multivariate linear regression analyses, older age, lower total cholesterol and higher HIV RNA were independently associated with higher NAG:UCr; older age, lower total cholesterol and lower CD4 cell count were independently associated with higher α1‐M:UCr.

Conclusions

In comparioson with HIV‐negative participants, PLWH were more likely to have tubular injury. Early antiretroviral treatment might mitigate the development of kidney injury.

A retrospective cohort study of early mortality among patients with HIV/TB co-infection in Shanghai municipality

OBJECTIVES

Tuberculosis (TB) is the most common and fatal opportunistic co-infection among HIV-infected individuals. While TB-associated mortality predominantly occurs in the first 90 days after admission, such a correlation remains unclear in HIV/TB co-infected patients. Thus, we aimed to investigate the 90-day mortality and associated risk factors among HIV/TB co-infected patients in China.

METHODS

Adult patients with HIV and a newly confirmed TB diagnosis admitted to the Shanghai Public Health Clinical Center between September 2009 and August 2017 were enrolled. Clinical and laboratory characteristics, key treatments and outcomes were collected retrospectively. The associations between different factors and early mortality were analysed.

RESULTS

Of the 485 laboratory-confirmed HIV/TB patients [median (range) age = 39 (19-79) years], 413 (85.15%) were male. Diagnosis was confirmed by culture, pathology and acid-fast bacilli smear alone in 362 (74.6%), 6 (1.2%) and 117 (24.1%) patients, respectively. Multiple drug-/rifampin-resistant TB was detected in 21 (5.8%) of the 367 patients with a positive culture. Rifampin or rifabutin was administered to 402 (82.9%) patients. Additionally, 66 (13.6%) and 86 (17.7%) died within 90 days and 1 year of admission, respectively. Of the 64 TB-related deaths, 59 (92.2%) occurred within 90 days of admission. In Cox regression, central nervous system (CNS) TB [odds ratio (OR) = 2.49, 95% confidence interval (CI): 1.46-4.23, P < 0.001], no antiretroviral therapy (ART) within 3 months after admission (OR = 11, 95% CI: 6.4-18.9, P < 0.001), and plasma albumin level < 25 g/L (OR = 1.91, 95% CI: 1.07-3.40, P = 0.021) were associated with early death.

CONCLUSIONS

Tuberculosis co-infection was prevalent and fatal in HIV-infected patients, with most deaths occurring within 90 days of admission. Early mortality was associated with CNS-TB, no ART, and serum albumin level < 25 g/L.

[Differential protein expressions in papillary thyroid carcinoma patients with or without Hashimoto's thyroiditis]

Objective: To explore the differential protein expressions in papillary thyroid carcinoma (PTC) with or without Hashimoto's thyroiditis (HT). Methods: Tissue microarray was prepared and the protein expression levels of v-Raf murine sarcoma viral oncogene homolog B1 (BRAF), vascular endothelial growth factor (VEGF), cyclinD1, mesothelial cell (MC) , CD56 and Galectin3 in the PTC tissues with or without HT were detected by immunohistochemical staining. Results: The positive expression rates of BRAF protein in the PTC tissues with or without HT groups were 55.4% (36/65) and 63.6% (42/66), respectively, without significant difference (P=0.336). The positive expression rates of VEGF protein in the PTC tissues with or without HT groups were 25.7% (19/74) and 25.8%(17/66), respectively, without significant difference (P=0.991). The positive expression rates of cyclin D1 protein in the PTC tissues with or without HT groups were 93.4% (71/76) and 97.6% (80/82), without significant difference (P=0.206). The positive expression rates of MC protein in the PTC tissues with or without HT groups were 86.1% (62/72) and 83.5%(71/85), without significant difference (P=0.654). The positive expression rates of Galectin3 protein in the PTC tissues with or without HT groups were 98.7% (76/77) and 97.5% (78/80), without significant difference (P=0.583). The positive expression rates of CD56 in the PTC tissues and adjacent thyroid follicular epithelial cells were 27.4% (32/117) and 65.0% (76/117), respectively, and the difference was statistically significant (P=0.001). The positive expression rates of CD56 in PTC tissues with or without HT were 35.5% (24/68) and 16.5% (13/79), respectively, and the difference was statistically significant (P=0.009). Conclusions: There are no significant differences in the expressions of BRAF, VEGF, CyclinD1, MC and Galectin3 between the PTC tissues with or without HT. However, the significantly differential expression of CD56 between the two group suggests that CD56 may be related to the pathogenesis of PTC with HT. CD56 may be used as a potential molecular marker in PTC diagnosis.

[Analysis of baseline liver biochemical parameters in 324 cases with novel coronavirus pneumonia in Shanghai area]

Objective: To summarize the clinical characteristics and liver biochemical parameters of 324 cases admitted with novel coronavirus pneumonia in Shanghai area. Methods: Clinical data and baseline liver biochemical parameters of 324 cases with novel coronavirus pneumonia admitted to the Shanghai Public Health Clinical Center from January 20, 2020 to February 24, 2020 were retrospectively analyzed. Patients were divided into two groups based on the status of illness: mild type (mild and typical) and severe type (severe and critical).The differences in clinical data and baseline liver biochemical parameters of the two groups were described and compared. The t-test and Wilcoxon rank-sum test were used for measurement data. The enumeration data were expressed by frequency and rate, and chi-square test was used. Results: Of the 324 cases with novel coronavirus pneumonia, 26 were severe cases (8%), with median onset of 5 days, 20 cases were HBsAg positive (6.2%), and 70 cases (21.6%) with fatty liver, diagnosed with X-ray computed tomography. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), total bilirubin (TBil), albumin(ALB) and international normalized ratio (INR) of 324 cases at baseline were 27.86 ± 20.02 U/L, 29.33 ± 21.02 U/L, 59.93 ± 18.96 U / L, 39.00 ± 54.44 U/L, 9.46 ± 4.58 μmol / L, 40.64 ± 4.13 g / L and 1.02 ± 0.10. Of which, ALT was > than the upper limit of normal (> ULN), accounting for 15.7% (51/324). ALT and AST > ULN, accounting for 10.5% (34/324). ALP > ULN, accounting for 1.2% (4/324). ALP and GGT > ULN, accounting for 0.9% (3/324). INR > ULN was lowest, accounting for 0.6% (2/324). There were no statistically significant differences (P > 0.05) in ALT [(21.5 vs. 26) U / L, P = 0.093], ALP [(57 vs.59) U/L, P = 0.674], and GGT [(24 vs.28) U/L, P = 0.101] between the severe group and the mild group. There were statistically significant differences in AST (23 U/L vs. 34 U/L, P < 0.01), TBil (10.75 vs. 8.05 μmol / L, P < 0.01), ALB (35.79 ± 4.75 vs. 41.07 ± 3.80 g/L, P < 0.01), and INR (1.00 vs. 1.04, P < 0.01). Conclusion: The baseline liver biochemical parameters of 324 cases with novel coronavirus pneumonia in Shanghai area was comparatively lower and the liverinjury degree was mild, and the bile duct cell damage was rare.

When facilitation meets clonal integration in forest canopies

Few studies have explored how - within the same system - clonality and positive plant-plant interactions might interact to regulate plant community composition. Canopy-dwelling epiphytes in species-rich forests provide an ideal system for studying this because many epiphytic vascular plants undertake clonal growth and because vascular epiphytes colonize canopy habitats after the formation of nonvascular epiphyte (i.e. bryophyte and lichen) mats. We investigated how clonal integration of seven dominant vascular epiphytes influenced inter-specific interactions between vascular epiphytes and nonvascular epiphytes in a subtropical montane moist forest in southwest China. Both clonal integration and environmental buffering from nonvascular epiphytes increased survival and growth of vascular epiphytes. The benefits of clonal integration for vascular epiphytes were higher when nonvascular epiphytes were removed. Similarly, facilitation from nonvascular epiphytes played a more important role when clonal integration of vascular epiphytes was eliminated. Overall, clonal integration had greater benefits than inter-specific facilitation. This study provides novel evidence for interactive effects of clonality and facilitation between vascular and nonvascular species, and has implications for our understanding of a wide range of ecosystems where both high levels of clonality and facilitation are expected to occur.

[Guidelines for diagnosis and treatment of dengue in China]

Dengue is the most prevalent and rapidly spreading mosquito-borne viral disease. As a dengue non-endemic country, China has experienced several dengue outbreaks in recent years. However, dengue patients in China displayed distinct clinical characteristics compared to patients in endemic countries. To standardize the diagnosis and treatment of dengue fever, the experts of the Society of Infectious Diseases, Society of Tropical Medicine and Parasitology of Chinese Medical Association, and the Society of Emergency Medicine, China Association of Chinese Medicine have reached this guideline based on guidelines for diagnosis, treatment, prevention and control of dengue (World Health Organization, 2009); guidelines for diagnosis and treatment of dengue (National Health and Family Planning Commission of the People's Republic of China, 2014, Edition 2), health industry standard of the People's Republic of China "diagnosis for dengue fever (WS216-2018)" and systemic reports on dengue. The guideline includes 8 aspects: introduction, terminology, epidemiology and prevention, etiology and pathogenesis, clinical features, diagnosis, treatment and problems to be solved.

[Expert consensus on the diagnosis and treatment of cryptococcal meningitis]

Cryptococcal meningitis is a common and refractory central nervous system infection, with high rates of mortality and disability. The experts of the Society of Infectious Diseases of Chinese Medical Association have reached this consensus after a thorough discussion. Based on the current situation of cryptococcal meningitis in China, the management of cryptococcal meningitis includes 6 aspects: introduction, microorganism identification, clinical manifestations and diagnosis, principles of antifungal therapy, treatment of refractory and recurrent meningitis, treatment of intracranial hypertension. There is not a separate consensus on human immunodeficiency virus (HIV) infection in patients with cryptococcal meningitis. This article focuses on different antifungal regimens and reducing intracranial pressure by reference to Infectious Disease Society of America (IDSA) guidelines. The importance of early diagnosis, combined long-term antifungal therapy, control of intracranial hypertension are emphasized.

Epiphytic bryophytes as bio-indicators of atmospheric nitrogen deposition in a subtropical montane cloud forest: Response patterns, mechanism, and critical load

Increasing trends of atmospheric nitrogen (N) deposition due to pollution and land-use changes are dramatically altering global biogeochemical cycles. Bryophytes, which are extremely vulnerable to N deposition, often play essential roles in these cycles by contributing to large nutrient pools in boreal and montane forest ecosystems. To interpret the sensitivity of epiphytic bryophytes for N deposition and to determine their critical load (CL) in a subtropical montane cloud forest, community-level, physiological and chemical responses of epiphytic bryophytes were tested in a 2-year field experiment of N additions. The results showed a significant decrease in the cover of the bryophyte communities at an N addition level of 7.4 kg ha^-1 yr^-1, which is consistent with declines in the biomass production, vitality, and net photosynthetic rate responses of two dominant bryophyte species. Given the background N deposition rate of 10.5 kg ha^-1yr^-1 for the study site, a CL of N deposition is therefore estimated as ca. 18 kg N ha^-1 yr^-1. A disordered cellular carbon (C) metabolism, including photosynthesis inhibition and ensuing chlorophyll degradation, due to the leakage of magnesium and potassium and corresponding downstream effects, along with direct toxic effects of excessive N additions is suggested as the main mechanism driving the decline of epiphytic bryophytes. Our results confirmed the process of C metabolism and the chemical stability of epiphytic bryophytes are strongly influenced by N addition levels; when coupled to the strong correlations found with the loss of bryophytes, this study provides important and timely evidence on the response mechanisms of bryophytes in an increasingly N-polluted world. In addition, this study underlines a general decline in community heterogeneity and biomass production of epiphytic bryophytes induced by increasing N deposition.

Organic nitrogen uptake is a significant contributor to nitrogen economy of subtropical epiphytic bryophytes

Without any root contact with the soil, epiphytic bryophytes must experience and explore poor, patchy, and heterogeneous habitats; while, the nitrogen (N) uptake and use strategies of these organisms remain uncharacterized, which obscures their roles in the N cycle. To investigate the N sources, N preferences, and responses to enhanced N deposition in epiphytic bryophytes, we carried out an in situ manipulation experiment via the (15)N labelling technique in an Asian cloud forest. Epiphytic bryophytes obtained more N from air deposition than from the bark, but the contribution of N from the bark was non-negligible. Glycine accounted for 28.4% to 44.5% of the total N in bryophyte tissue, which implies that organic N might serve as an important N source. Increased N deposition increased the total N uptake, but did not alter the N preference of the epiphytic bryophytes. This study provides sound evidence that epiphytic bryophytes could take up N from the bark and wet deposition in both organic and inorganic N forms. It is thus important to consider organic N and bark N sources, which were usually neglected, when estimating the role of epiphytic bryophytes in N cycling and the impacts of N deposition on epiphytic bryophytes in cloud forests.

Survival and Growth of Epiphytic Ferns Depend on Resource Sharing

Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing) on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets) and another on groups (several ramets within a plot), with severed and intact rhizome treatments (without and with physiological integration) on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium) in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration) significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

Higher clonal integration in the facultative epiphytic fern Selliguea griffithiana growing in the forest canopy compared with the forest understorey

BACKGROUND AND AIMS

The advantage of clonal integration (resource sharing between connected ramets of clonal plants) varies and a higher degree of integration is expected in more stressful and/or more heterogeneous habitats. Clonal facultative epiphytes occur in both forest canopies (epiphytic habitats) and forest understories (terrestrial habitats). Because environmental conditions, especially water and nutrients, are more stressful and heterogeneous in the canopy than in the understorey, this study hypothesizes that clonal integration is more important for facultative epiphytes in epiphytic habitats than in terrestrial habitats.

METHODS

In a field experiment, an examination was made of the effects of rhizome connection (connected vs. disconnected, i.e. with vs. without clonal integration) on survival and growth of single ramets, both young and old, of the facultative epiphytic rhizomatous fern Selliguea griffithiana (Polypodiaceae) in both epiphytic and terrestrial habitats. In another field experiment, the effects of rhizome connection on performance of ramets were tested in small (10 × 10 cm(2)) and large (20 × 20 cm(2)) plots in both epiphytic and terrestrial habitats.

KEY RESULTS

Rhizome disconnection significantly decreased survival and growth of S. griffithiana in both experiments. The effects of rhizome disconnection on survival of single ramets and on ramet number and growth in plots were greater in epiphytic habitats than in terrestrial habitats.

CONCLUSIONS

Clonal integration contributes greatly to performance of facultative epiphytic ferns, and the effects were more important in forest canopies than in forest understories. The results therefore support the hypothesis that natural selection favours genotypes with a higher degree of integration in more stressful and heterogeneous environments.

Water relations and gas exchange of fan bryophytes and their adaptations to microhabitats in an Asian subtropical montane cloud forest

Fan life forms are bryophytes with shoots rising from vertical substratum that branch repeatedly in the horizontal plane to form flattened photosynthetic surfaces, which are well suited for intercepting water from moving air. However, detailed water relations, gas exchange characteristics of fan bryophytes and their adaptations to particular microhabitats remain poorly understood. In this study, we measured and analyzed microclimatic data, as well as water release curves, pressure-volume relationships and photosynthetic water and light response curves for three common fan bryophytes in an Asian subtropical montane cloud forest (SMCF). Results demonstrate high relative humidity but low light levels and temperatures in the understory, and a strong effect of fog on water availability for bryophytes in the SMCF. The facts that fan bryophytes in dry air lose most of their free water within 1 h, and a strong dependence of net photosynthesis rates on water content, imply that the transition from a hydrated, photosynthetically active state to a dry, inactive state is rapid. In addition, fan bryophytes developed relatively high cell wall elasticity and the osmoregulatory capacity to tolerate desiccation. These fan bryophytes had low light saturation and compensation point of photosynthesis, indicating shade tolerance. It is likely that fan bryophytes can flourish on tree trunks in the SMCF because of substantial annual precipitation, average relative humidity, and frequent and persistent fog, which can provide continual water sources for them to intercept. Nevertheless, the low water retention capacity and strong dependence of net photosynthesis on water content of fan bryophytes indicate a high risk of unbalanced carbon budget if the frequency and severity of drought increase in the future as predicted.

Comparison between meat quality of Hanzhong White pigs and carcass weight

A total of 48 carcasses of crossbred Hanzhong White pigs were divided into 3 groups (I, 90-99 kg; II, 100-109 kg; III, 110-119 kg) to investigate the influence of carcass weight on meat quality. The intramuscular fat content of the 3 groups increased from 1.90 to 4.90%; for meat color, Warner-Bratzler shear force, drip loss, and oxidation-type muscle fiber percentage, and muscle fiber diameter of the longissimus lumborum, the indices in group II and group III were better than those in group I (P < 0.05). The saturated fatty acid and polyunsaturated fatty acid percentages of the longissimus lumborum muscle (2.80 and 37.30%, respectively) in group II were significantly lower than those in the other 2 groups, while the monounsaturated fatty acid percentage was the highest (59.10%). In conclusion, our results suggest that a carcass weight of 100-109 kg is sufficient to produce acceptable meat quality of Hanzhong White pigs.

Type I aortic dissection in a patient with human immunodeficiency virus infection

The use of highly active antiretroviral therapy in patients with HIV infection has significantly reduced HIV-related infectious complications and improved their survival. With effective antiretroviral therapy, cardiovascular disease has gained prominence as a cause of morbidity and mortality in HIV-infected persons. Aortic dissection is an uncommon but potentially fatal disease with catastrophic complications. The spread of AIDS is a major public health problem in China, but there is scant literature regarding the clinical outcome for HIV/AIDS patients with aortic dissection in China. This case report describes a patient with HIV and type I aortic dissection who survived without surgical repair. This report is provided to describe a detailed and successful outcome for a patient with type I aortic dissection and HIV in China.

Clinical features, treatments and prognosis of the initial cases of pandemic influenza H1N1 2009 virus infection in Shanghai China

BACKGROUND AND OBJECTIVE

As of 13 December 2009, more than 208 countries and overseas territories or communities have reported laboratory-confirmed cases of pandemic influenza H1N1 2009, which have resulted in at least 10 582 deaths. As of 7 December 2009, 4328 severe cases were reported in Mainland China, resulting in 326 deaths. This study's objective was to determine the clinical features, treatments and prognosis of the initial cases of Pandemic influenza H1N1 2009 virus infection in Shanghai, China, and how its clinical features related to patient gender.

METHODS

A total of 224 confirmed 2009 influenza A/H1N1-infected patients treated and discharged by Shanghai Public Health Clinical center between 24 May and 20 July 2009 were included in the study. Patients' personal information, signs and symptoms, laboratory and imagery data, disease course, hospitalization period and seroconversion duration for viral nucleic acid after antiviral treatment were analyzed.

RESULTS

Among the 224 patients, 118 were male and 106 were female, yielding a sex ratio of 1.1:1. Approximately 52% of the patients came from Australia, and 63.8% were between 18 and 40 years old. Clinical manifestations included fever, cough and congestion of the throat, and lab findings were characterized by elevated C-reaction protein (CRP) and neutrophils. Female patients had significantly lower serum Prealbumin (PA) levels than male patients (P < 0.05). The patients' serum CRF levels significantly decreased after treatment (P < 0.05), while the levels of CD3, CD4 and CD8 significantly increased after treatment (P < 0.01). Approximately 29.9% of the patients had abnormal signs on chest computer tomography scan, and 21.9% had obvious signs indicating pneumonia. However, blood cultures were negative in these patients. The average disease course was 3.9 +/- 1.4 days, the average hospitalization period was 5.0 +/- 1.7 days, and the seroconversion duration for viral nucleic acid after antiviral treatment was 3.8 +/- 1.3 days.

CONCLUSION

Initial cases of pandemic influenza H1N1 2009 were characterized by fever, cough and throat congestion, with elevated CRP and neutrophils being the most significant lab findings. The pandemic influenza H1N1 2009 strain was able to affect multiple organs, including the hepatic synthesis of PA and immune functioning. The novel 2009 Influenza A/H1N1 virus was mild clinically, with a short disease course and good prognosis.

[Seasonal variation of soil respiration and its components in tropical rain forest and rubber plantation in Xishuangbanna, Yunnan]

By using trenching method and infrared gas analyzer, this paper studied the seasonal variation of soil respiration (SR), including root respiration (RR) and heterotrophic respiration (HR), in tropical seasonal rain forest (RF) and rubber (Hevea brasiliensis) plantation (RP) in Xishuangbanna of Yunnan, China. The results showed that the SR and HR rates were significantly higher in RF than in RP (P < 0.01), while the RR rate had less difference between the two forests. Soil temperature and moisture were the key factors affecting the SR, RR and HR. The SR and HR rates in the two forests were rainy season > dry-hot season > foggy season, but the RR rate was rainy season > foggy season > dry-hot season in RF, and foggy season > rainy season > dry-hot season in RP. The contribution of RR to SR in RF (29%) was much lower than that in RP (42%, P < 0.01), while the contribution of HR to SR was 71% in RF and 58% in RP. When the soil temperature at 5 cm depth varied from 12 degrees C to 32 degrees C, the Q10 values for SR, HR, and RR rates were higher in RF than in RP. HR had the highest Q10 value, while RR had the lowest one.

A computational study of the interaction noise from a small axial-flow fan

Small axial-flow fans used for computer cooling and many other appliances feature a rotor driven by a downstream motor held by several cylindrical struts. This study focuses on the aerodynamic mechanism of rotor-strut interaction for an isolated fan. The three-dimensional, unsteady flow field is calculated using FLUENT, and the sound radiation predicted by acoustic analogy is compared with measurement data. Striking differences are found between the pressure oscillations in various parts of the structural surfaces during an interaction event. The suction surface of the blade experiences a sudden increase in pressure when the blade trailing edge sweeps past a strut, while the process of pressure decrease on the pressure side of the blade is rather gradual during the interaction. The contribution of the latter towards the total thrust force on the structure is cancelled out significantly by that on the strut. In terms of the acoustic contributions from the rotor and strut, the upstream rotor dominates and this feature differs from the usual rotor-stator interaction acoustics in which the downstream part is responsible for most of the noise. It is therefore argued that the dominant interaction mechanism is potential flow in nature.

Genetic modification of hematopoietic progenitor cells for combined resistance to 4-hydroperoxycyclophosphamide, vincristine, and daunorubicin

AIM

To investigate whether human peripheral blood hematopoietic progenitor cells (PBPC) modified with human aldehyde dehydrogenase class-3 gene (ALDH-3) and multidrug resistance gene 1 (MDR1) would increase chemotherapy resistance to 4-hydroperoxycyclophosphamide (4-HC) and -glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and used to transfect the packaging cell lines PA317 by electroporation. CD34+ PBPC were isolated with a high-gradient magnetic cell sorting system (MACS), and then were transfected with supernatant of retrovirus containing human ALDH-3 and MDR1 cDNA. PCR, RT-PCR, Southern blot, Northern blot, FACS, and MTT assay were used to evaluate the transfection and expression of the transgene in target cells.

RESULTS

The bicistronic retroviral vector construction was verified by PCR and restriction endonuclease analysis. Dual drug resistance genes were integrated into the genomic DNA of CD34+ PBPC and expressed efficiently. The efficiency of gene transfection in CD34+ PBPC was tested to be 18 % on colonies. Nested PCR and Neor rescue assay indicated that no helper virus was present in this system. Compared with the untransduced cells, transgene recipient cells conferred 4.5-fold resistance to 4-HC, 6.6-fold and 7.8-fold resistance to P-glycoprotein effluxed drug, vincristine and daunorubicin, respectively.

CONCLUSION

Efficient transduction of two different types of drug resistance genes into human peripheral blood hematopoietic progenitor cells and the co-expression may decrease cumulative myelosuppression of combination chemotherapy.

[Mechanism of injury of intestine, liver and lung in acute cholangitis of severe type model and the protective effect of huoxue qingjieling]

Lung capillary permeability was measured with 125I labelled bovine serum albumin, the progression of hepato-cellular injury was quantitatively assessed using atriphenyltetrazolium chloride assay, injury of small intestinal mucosa was determined by the changes of diamine oxidase (DAO) level, content of oxygen free radicals (OFR) was measured by electron spin resonance spectrometer and levels of phospholipase A2(PLA2) of intestine, hepatocellular viability were observed by bioassay methods respectively. The results showed that function of lung, liver and intestine was seriously injuried in ACST rats. These injuries demonstrated by increase of capillary permeability and decrease of hepatocellular viability as well as DAO in intestinal mucosa (P < 0.01) in comparing with control, while the levels of OFR and PLA2 in the above-mentioned 3 organs were elevated simultaneously (P < 0.01). As for the comparison of efficacy of different treatment, Huoxue Qingjieling was the best one, the bile duct decompression or ampicillin showed little benefit on injury protection even aggravated in some tissues, they displayed a close relationship with their influence on the OFR and PLA2. Besides, the levels of OFR or PLA2 in various tissues were different from each other, therefore, the serum levels of OFR or PLA2 can not reflect the real levels occurred in organ or tissue level.

Reduced water exchange in sickle cell anemia red cells: a membrane abnormality

We have measured the diffusional water permeability of sickle cell anemia red blood cells under isotonic conditions using pulsed nuclear magnetic resonance (NMR) techniques. We have found that the equilibrium diffusional permeability for sickle cells is about 1.61.10(-3) cm/s, or about 60% of the value measured for normal cells. This abnormality is not related to the heterogeneity generally found in cell populations in sickle red cells with different mean corpuscular hemoglobin concentrations. We speculate that the abnormality of water exchange under isotonic conditions in sickle cells reflects an alteration of membrane proteins responsible for water exchange, possibly caused by oxidation of Band 3 proteins.

Quantitative detection of rapid motions in spectrin by NMR

Previous high resolution proton NMR data on human erythrocyte spectrin molecules has indicated the existence of regions exhibiting rapid internal motions within the intact molecules [L. W.-M. Fung, H.-Z. Lu, R. P. Hjelm, jr, M. E. Johnson, FEBS Lett., 197, 234 (1986)]. We have extended the studies by developing quantitative NMR methods to determine the fraction of spectrin protons exhibiting rapid internal motions, in both the isolated molecule and within the spectrin-actin network. Using both one-pulse and spin echo pulse sequences, we find that the fraction of the protons in rapid motion is about 15% of the total protons in the spectrin molecule at 37 degrees C in phosphate buffer with 150 mM NaCl at pH 7.4. Quantitative information on these rapid motions will be important in understanding the structural, mechanical and functional properties of spectrin molecules, as well as in understanding filamentous protein structures in general.

Selective detection of rapid motions in spectrin by NMR

Human erythrocyte spectrin molecules exhibit relatively sharp (30-50 Hz) proton NMR signals in the aliphatic region. A standard solvent presaturation pulse sequence that also partially suppresses the broad envelope from protons with rigid structures in spectrin and selectively enhances the sharp resonances has been used to characterize the behavior of these resonances. The overall resonance pattern strongly resembles that of the denatured spectrin. The observed spectra are also quite similar to the line-broadened spectrum from a mixture of amino acids that corresponds to the composition of the spectrin molecule. These data indicate the existence of regions exhibiting rapid internal motions within the intact spectrin molecule, and suggest that the amino acid composition of the residues giving rise to the sharp resonances is quite similar to that of the full spectrin molecule.

Binding of a spin-labeled phenylalanine analog to sickle hemoglobin: EPR and NMR studies

We have synthesized a spin-label analog of phenylalanine as a competitive inhibitor probe of the sickle hemoglobin aggregation process. Sickle hemoglobin gelation measurements indicate that the spin-label phenylalanine analog is a potent inhibitor of deoxy sickle hemoglobin aggregation. We have also used spin label EPR and high-resolution proton NMR to study the interaction of the phenylalanine analog with hemoglobin, and find that the kinetic off-rate is comparable to, or slower than the hemoglobin rotational rate (i.e., greater than or equal to 10(8) s-1), and that at least one, and perhaps two significant localized interaction region(s) exist within a few angstroms of the beta chain N- and C-termini. Correlation with other known structural information suggests that the observed interaction sites may be relevant to the mechanism for inhibition of sickle hemoglobin aggregation.