Opposing mechanisms affect taxonomic convergence between tree assemblages during tropical forest succession.

Whether successional forests converge towards an equilibrium in species composition remains an elusive question, hampered by high idiosyncrasy in successional dynamics. Based on long-term tree monitoring in second-growth (SG) and old-growth (OG) forests in Costa Rica, we show that patterns of convergence between pairs of forest stands depend upon the relative abundance of species exhibiting distinct responses to the successional gradient. For instance, forest generalists contributed to convergence between SG and OG forests, whereas rare species and old-growth specialists were a source of divergence. Overall, opposing trends in taxonomic similarity among different subsets of species nullified each other, producing a net outcome of stasis over time. Our results offer an explanation for the limited convergence observed between pairwise communities and suggest that rare species and old-growth specialists may be prone to dispersal limitation, while the dynamics of generalists and second-growth specialists are more predictable, enhancing resilience in tropical secondary forests.

[Relationship between personality characteristics and turnover intention of medical staff in an infectious disease hospital].

Objective: To investigate the relationship between personality characteristics and turnover intention of the medical staff in an infectious diseases hospital. Methods: Using the cluster sampling method, a total of 366 members of medical staff were selected from different departments in an infectious disease hospital from May to August, 2013. The general information, such as sex, age, education level, and professional title, were collected and they were subjected to a survey using Cattell's 16 Personality Factor Questionnaire and Turnover Intention Scale. The data were subjected to logistic regression analysis. Results: Compared with the Chinese norm, the medical staff in the infectious disease hospital had significantly higher scores of intelligence, stability, bullying, excitability, perseverance, social boldness, fantasy, privateness, independence, and self-discipline and significantly lower scores of gregariousness, sensitivity, suspicion, anxiety, and tension (P<0.05). Of the 366 members of medical staff, 22 (6.01%) had a very low turnover intention, low in 152 (41.53%) , high in 61 (16.67%) , and very high in 131 (35.79%). The logistic regression analysis showed that sensitivity, suspicion, fantasy, privateness, anxiety, openness to change, and independence were the risk factors for turnover intention (P<0.05) . Conclusion: Compared with the Chinese norm, the medical staff in the infectious disease hospital have a better mental quality and a higher turnover intention. The individuals with sensitivity, suspicion, fantasy, and anxiety are prone to having turnover intention.

Calcitonin alleviates hyperalgesia in osteoporotic rats by modulating serotonin transporter activity.

Calcitonin may relieve pain by modulating central serotonin activity. Calcitonin partly reversed the hypersensitivity to pain induced by ovariectomy. This suggests that the anti-nociceptive effects of calcitonin in the treatment of osteoporosis may be mediated by alterations in neural serotonin transporter (SERT) activity. INTRODUCTION: This study used a rat model of osteoporosis to evaluate the role of the cerebral serotonin system in the anti-nociceptive effect of calcitonin, a drug used to treat post-menopausal osteoporosis. METHODS: Osteoporosis was induced in rats by ovariectomy (OVX). Rats were then randomized to the following four groups: sham operation, OVX, OVX plus calcitonin, or OVX plus alendronate. RESULTS: OVX led to alterations in bone micro-architecture; alendronate strongly reversed this effect, and calcitonin moderately reversed this effect. OVX increased hyperalgesia (determined as the time for hind paw withdrawal from a heat source); calcitonin reduced this effect, but alendronate had no effect. OVX increased the expression of c-Fos (a neuronal marker of pain) in the thalamus; calcitonin strongly reversed this effect, and alendronate moderately reversed this effect. OVX also reduced SERT but increased 5-HT1A receptor expression and activity; calcitonin aggravated this effect, but alendronate had no effect on recovery of SERT/5-HT1A activity and expression. CONCLUSIONS: Our study of a rat model of osteoporosis suggests that OVX-induced enhancement of the serotonergic system may protect against hyperalgesia. However, the anti-nociceptive effects of calcitonin in osteoporosis may be mediated by decreased neural SERT activity and increased activation of 5-HT1 receptors in the thalamus.

Development and characterization of 22 polymorphic microsatellite markers for the balloon flower Platycodon grandiflorum (Campanulaceae).

The balloon flower (Platycodon grandiflorum A. DC.) is a perennial flowering plant of the Campanulaceae family; it is the only member of the genus Platycodon. Information on the genetic diversity of balloon flower populations is of great importance for the conservation and germplasm utilization of this flowering plant. Twenty-two polymorphic microsatellite loci were developed and characterized with eight balloon flower accessions collected from South Korea and China. Eighty-one alleles were detected among the eight balloon flower accessions. The number of alleles per locus ranged from two to six, with a mean of four alleles per locus. The observed and expected heterozygosity values ranged from 0.000 to 0.875 (mean = 0.355) and 0.117 to 0.766 (mean = 0.489), respectively. The polymorphic information content values ranged from 0.110 to 0.733, with a mean of 0.449. These new microsatellite markers will be useful for population and conservation genetic studies of P. grandiflorum.

Nasal glioma.

Nasal gliomas are uncommon congenital lesions arising from abnormal embryonic development. Clinically, these masses are firm and incompressible. Histologically, they are made up of astrocytes and neuroglial cells, embedded in fibrous and vascular connective tissue. Proper management of a nasal glioma requires a multidisciplinary approach including an otorhinolaryngologist, radiologist, and neurosurgeon. Radiological investigations such as computed tomography or magnetic resonance imaging should be performed to exclude intracranial extension. The mainstay of treatment is conservative surgical excision because nasal gliomas are slow-growing, rarely recurrent, and have no malignant potential. We report one case of nasal glioma in a Chinese infant. He had an uncomplicated surgical intervention with a good cosmetic result. A review of the clinical features of and diagnostic approach to nasal gliomas is also presented.

Network Signatures of IgG Immune Repertoires in Hepatitis B Associated Chronic Infection and Vaccination Responses.

The repertoire of IgG antibody responses to infection and vaccination varies depending on the characteristics of the immunogen and the ability of the host to mount a protective immune response. Chronic hepatitis B virus (HBV) infections are marked by persistent infection and immune tolerance to vaccination. This disease offers a unique opportunity to discover key repertoire signatures during infection and in response to vaccination. Complementarity determining region 3 of an antibody heavy chain (CDR-H3) has a major impact on the antigenic specificity of an antibody. We used next-generation sequencing to characterize the CDR-H3 sequences in paired siblings of 4 families in which only one member of each pair had chronic HBV infection. Blood samples were obtained before and 2 weeks after HBV vaccination. The analysis revealed a huge network of sequence-related CDR-H3 clones found almost exclusively among carriers. In contrast, vaccination induced significant increases of CDR-H3 cluster diversities among siblings without hepatitis B. Several vaccination-associated clone clusters were identified. Similar findings of vaccination-associated clone networks were observed in healthy adults receiving HBV boosters. These strategies can be used to identify signatures of other infectious diseases and accelerate discoveries of antibody sequences with important biomedical implications.

The reactivity of the sulphydryl groups of chorismate mutase/prephenate dehydratase--a bifunctional enzyme of phenylalanine biosynthesis in Escherichia coli K12.

The reaction of N-ethylmaleimide with chorismate mutase/prephenate dehydratase (chorismate pyruvatemutase/prephenate hydrolyase (decarboxylating) EC 5.4.99.5/EC 4.2.1.51) from Escherichia coli K12, which leads to the preferential inactivation of the prephenate dehydratase activity (Gething, M-J.H. and Davidson, B.E. (1977) Eur. J. Biochem. 78, 111-117), was found to involve only the sulphydryl groups of the enzyme. Determination of the reactivities of the four different cysteine residues indicated that the reaction was not specific for a single residue, although two residues (Cys-216 and Cys-374) were more reactive than the others. The amount of inhibition of the prephenate dehydratase activity approximated in extent to the sum of the stoichiometries of the individual reactions of N-ethylmaleimide with these two cysteine residues. In the presence of either phenylpyruvate, the product of the prephenate dehydratase activity, or cis-aconitate, a competitive inhibitor with respect to prephenate, the prephenate dehydratase activity was substantially protected from inactivation. This protection was concomitant with a significant decline in the reactivities of both Cys-216 and Cys-374. These results are interpreted as indicating that both of these cysteine residues are at, or near to, the prephenate dehydratase active site and are possibly essential for the prephenate dehydratase activity of the enzyme.

Endoscopic-guided adenoidectomy using a classic adenoid curette: a simple way to improve adenoidectomy.

A total of 13 adenoidectomies using a nasal endoscopic-guided transoral adenoid curette (not yet a published standardised method) were performed to treat snoring. Nasal endoscopy allows easy assessment of the size of the adenoids and improves the accuracy of the adenoidectomy. This technique is particularly useful for paediatric patients who have small oral cavities. The assessment and excision of the adenoids in these cases are often difficult. Using the nasal endoscope, the curette can be accurately inserted at the superior border of the adenoid, allowing the complete transoral removal of the main bulk of the adenoid tissue. All 13 patients showed considerably decreased snoring and improvements in the quality of sleep as reported by the parents and the patients. We believe that nasal endoscopic-guided transoral adenoidectomy is a viable alternative to classic adenoidectomy. This technique also has the advantage of using commonly available simple ear, nose, and throat instruments.

Expected Shannon Entropy and Shannon Differentiation between Subpopulations for Neutral Genes under the Finite Island Model.

Shannon entropy H and related measures are increasingly used in molecular ecology and population genetics because (1) unlike measures based on heterozygosity or allele number, these measures weigh alleles in proportion to their population fraction, thus capturing a previously-ignored aspect of allele frequency distributions that may be important in many applications; (2) these measures connect directly to the rich predictive mathematics of information theory; (3) Shannon entropy is completely additive and has an explicitly hierarchical nature; and (4) Shannon entropy-based differentiation measures obey strong monotonicity properties that heterozygosity-based measures lack. We derive simple new expressions for the expected values of the Shannon entropy of the equilibrium allele distribution at a neutral locus in a single isolated population under two models of mutation: the infinite allele model and the stepwise mutation model. Surprisingly, this complex stochastic system for each model has an entropy expressable as a simple combination of well-known mathematical functions. Moreover, entropy- and heterozygosity-based measures for each model are linked by simple relationships that are shown by simulations to be approximately valid even far from equilibrium. We also identify a bridge between the two models of mutation. We apply our approach to subdivided populations which follow the finite island model, obtaining the Shannon entropy of the equilibrium allele distributions of the subpopulations and of the total population. We also derive the expected mutual information and normalized mutual information ("Shannon differentiation") between subpopulations at equilibrium, and identify the model parameters that determine them. We apply our measures to data from the common starling (Sturnus vulgaris) in Australia. Our measures provide a test for neutrality that is robust to violations of equilibrium assumptions, as verified on real world data from starlings.

Intrastriatal transplantation of Sertoli cells may improve amphetamine-induced rotation and tyrosine hydroxylase immunoreactivity of the striatum in hemiparkinsonian rats.

This study investigated survival and neurotrophic effects of Sertoli cells transplanted in the striatum of 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rats. Primary cultures of Sertoli cells were established from 3-week old rats and characterized by associated marker, placental cadherin (P-cadherin). Two months after transplantation, amphetamine-induced rotations of rats transplanted with Sertoli cells were significantly lower than those of control rats. However, restoration of tyrosine hydroxylase (TH) immunoreactivity and Sertoli cells that expressed P-cadherin were only found in the striatum of the rat that showed full recovery from amphetamine-induced rotation 3 months after transplantation without immunosuppression. These results suggest that Sertoli cells transplanted in striatum of hemiparkinsonian rats may survive for at least 3 months, and improve amphetamine-induced rotation and restore TH immunoreactivity.

Osteoradionecrosis of the temporal bone: a surgical technique of treatment.

Osteoradionecrosis of the temporal bone is a well-documented complication of radiotherapy to the ear, with potentially lethal complications. Three cases of advanced disease, treated surgically, are presented. In two of these, subtotal petrosectomy with blind-sac closure of the external auditory canal was carried out via an anterior approach. The enclosed space was obliterated with pedicled temporalis muscle. Primary healing took place. One case was similarly obliterated using a prolonged posterior incision. The wound broke down, requiring a microvascular free flap for closure. Radiotherapy jeopardizes the viability of skin flaps. An anterior incision bases the flap behind on the occipital and postauricular arteries. When radiotherapy has been used, this incision has theoretical and practical advantages over a standard posterior incision.

99mTc-TRODAT-1 SPECT in healthy and 6-OHDA lesioned parkinsonian monkeys: comparison with 18F-FDOPA PET.

Parkinson's disease (PD) is a degeneration of the nigrostriatal dopaminergic pathway, leading to a selective loss of dopamine in the striatum. 99mTc-TRODAT-1 is a recently developed radiotracer that selectively binds to the dopamine transporters, which are significant because loss of these transporters corresponds with a loss of dopaminergic neurons. The present investigation compared 99mTc-TRODAT-1 single photon emission computed tomography (SPECT) with 18F-FDOPA positron emission tomography (PET) in the evaluation of PD using a primate model. Three monkeys, including one 6-hydroxydopamine lesioned PD model and two controls, were examined by both 99mTc-TRODAT-1 SPECT and 18F-FDOPA PET. For the PD monkey, expression of parkinsonian behaviour and 18F-FDOPA PET were used to evaluate the severity of the lesion. 99Tc-TRODAT-1 was prepared from a lyophilized kit. After intravenous injection of the radiotracer, SPECT was acquired over 4 h using a dual-head camera equipped with ultra-high resolution fan-beam collimators. Both uptake measurement and visual assessment were performed. Data were compared with motor behaviour and PET imaging. The striatal uptake in both healthy and PD monkeys increased continuously during the study, although the gradient of increase was less prominent in the diseased monkey. The increased uptake in the controls appeared to become blunt around 4 h after injection. A profound decrease of 99Tc-TRODAT-1 uptake was found in the striatum of the PD monkey compared with the controls (0.91 vs 2.16). In the PD monkey, the decrease of striatal uptake contralateral to the more affected side of the body was more prominent compared to the ipsilateral side (0.77 vs 1.06). In addition, greater loss occurred in the contralateral side of the putamen (0.54 vs 1.04). Changes of uptake ratios in the striatum and its subnuclei of the PD monkey were significantly correlated with those measured from PET. The loss of striatal uptake appeared greater in SPECT than the corresponding PET with both visual and uptake analyses. In conclusion, our data in a limited series of cases indicate that 99Tc-TRODAT-1 with a conventional nuclear medicine camera system may provide a suitable tool in evaluating parkinsonism in a primate model.

Variations of the cystic artery in Chinese adults.

The origin and course of the cystic artery related to the Calot triangle were studied in 72 autopsies. The cystic artery arises from many possible origins; the right hepatic artery is the most common origin (76.6%). The Calot triangle (hepatocystic triangle), which is an important imaginary referent area for biliary surgery, is bounded by the common hepatic duct (CHD), the cystic duct, and the cystic artery. Of all the cystic arteries, 86.1% coursed through the Calot triangle, and 100% of the cystic arteries originating from the right hepatic artery coursed through the Calot triangle. However, only 54% of the cystic arteries that originated from the left, bifurcation, proper, and common hepatic arteries ran through the triangle. None of the cystic arteries that originated from the gastroduodenal, celiac, superior mesentery, or superior pancreaticoduodenal arteries passed through the triangle. Furthermore, 72.7% of the cystic arteries that originated from the right hepatic artery ran beneath the CHD as they entered the Calot triangle; the others ran anterior to the CHD. Of the cystic arteries that arose from locations other than the right hepatic artery, 29.4% ran posterior to the CHD, and 11.8% ran anterior to the CHD. The current study provides detailed information about anatomic variance in Chinese adults that may help avoid injury during open or laparoscopic cholecystectomies.

Silastic medialization for unilateral vocal fold palsy.

From August 1994 to September 1995, 12 silastic medialization procedures were performed for the treatment of vocal fold palsy. The causes included tuberculous fibrosis, carcinoma of the bronchus, post-oesophagectomy for carcinoma of the oesophagus and idiopathy. Early operation was performed in cases due to malignant conditions to relieve symptoms. In those with benign conditions, operation was performed if conservative treatment failed to control the symptoms in six months. The efficacy of silastic medialization for the treatment of dysphonia was evaluated by both subjective and objective voice assessment. The results indicate that the procedure is effective in the relief of dysphonia in unilateral vocal fold palsy. Only one patient in the study required a revision operation due to unsatisfactory voice quality. The procedure has the advantages of being tunable, reversible, and suitable for old and debilitated patients. The long term benefits of the procedure require further study.

Facial nerve tumours or 'all that palsies is not Bell's'.

Most cases of facial nerve palsy are idiopathic, that is to say, Bell's palsy. A few cases are due to tumours on the facial nerve. Early diagnosis will avoid extensive tissue destruction with loss of hearing and lead to satisfactory facial reinnervation. Five cases are presented. In three, there was a significant delay in diagnosis. A facial nerve tumour generally presents as a paralysis of slow onset and the degree of paralysis often fluctuates. Diagnosis can be made in most cases by high resolution CT.

Aural tuberculosis.

Tuberculous otitis media can present with very nonspecific clinical features. Five cases of tuberculous otitis media are reviewed over a period of 5 years. Significant clinical findings included the presence of abundant granulation tissue in mastoids with good pneumatization, cervical lymphadenopathy, profound hearing loss, facial palsy, and foci of tuberculous infection at other sites. Histologic examination of granulation tissue showed tuberculoid granulomata in all cases. The mycobacteria could be identified in two of the biopsies but not on cultures. Other conditions that give rise to tuberculoid granulomata should be searched for in cases where the myobacteria cannot be identified. In one case, diagnosis was delayed because the operative specimen was neither histologically examined nor sent for culture. Persistent otorrhea and recurring granulomata after mastoidectomy provided other important clinical features. All cases responded well to antituberculous chemotherapy. Surgery is indicated nowadays for facial palsy, subperiosteal abscess, fistula formation, labyrinthitis, intracranial complication, or infrequency for resistant mycobacterial infection caused by the non-tuberculous mycobacteria.