Pentatrichomonas hominis: first isolation from the feces of a dog with diarrhea in China

A trichomonad-like parasite isolated from canine fecal samples in Changchun, China was successfully cultivated in vitro using RPMI1640 medium supplemented with 10% heat-inactivated calf serum and antibiotics. These were then subjected to scanning and transmission electron microscopy for ultrastructural study. This parasite has four anterior flagella of unequal length, one independent flagellum, and one recurrent flagellum. It exhibits an anterior nucleus, a Golgi complex, an axostyle, food vacuoles, and hydrogenosomes. These features are consistent with the ultrastructural characteristics of previously described Pentatrichomonas hominis. Polymerase chain reaction and sequence analysis of three genetic loci, including ITS1-5.8S rRNA-ITS2, 18S rRNA, and EF-1α, were also used to compare these samples with other trichomonad species. Molecular identification was also consistent with P. hominis. This is the first time that isolation of P. hominis has been isolated from dog in China, although several other strains of P. hominis have been isolated from human samples.

Eimeria maxima: efficacy of recombinant Mycobacterium bovis BCG expressing apical membrane antigen1 against homologous infection

Coccidiosis is one of the most important protozoan diseases and inflicts severe economic losses on the poultry industry. The aim of this study was to evaluate the capacity of Bacillus Calmette-Guerin (BCG) to deliver apical membrane antigen1 (AMA1) of Eimeria maxima to stimulate specific cellular and humoral immune responses in chickens. Day-old birds were immunized twice with rBCG/pMV261-AMA1, rBCG/pMV361-AMA1, or BCG via oral, intranasal, and subcutaneous routes and then orally challenged with homologous E. maxima sporulated oocysts. Gain of body weight, fecal oocyst output, lesion scores, serum antibody responses, numbers of splenocyte CD4(+) and CD8(+) T cells, and gut cytokine transcript levels were assessed as measures of protective immunity. Challenge experiments demonstrated that rBCG vaccination via intranasal or subcutaneous routes could increase weight gain, decrease intestinal lesions, and reduce fecal oocyst shedding, and the subcutaneous and intranasal routes were superior to the oral route based on the immune effects. Furthermore, intranasal rBCG immunization could also lead to a significant increase in serum antibody, the percentage of CD4+ and CD8+ T lymphocyte cells, and the levels of IL-1β, IFN-γ, IL-15, and IL-10 mRNAs compared with the control group. These results suggested that intranasal rBCG immunization could induce a strong humoral and cellular response directed against homologous E. maxima infection. This study provides data for the use of rBCG to develop a prophylactic vaccine against coccidiosis.

[Virological surveillance of pandemic (H1N1) 2009 virus and its genetic characteristics in Hunan Province, 2009-2011]

To understand and master the dynamic variation of the pandemic influenza A (H1N1) 2009 in Hunan province from 2009 to 2011, and to know the genetic characteristics and drug resistance of the pandemic (H1N1) 2009 viruses. Throat swab specimens of influenza-like illness patients were collected from sentinel hospitals and tested for influenza by fluorescent PCR or virus isolation methods. Partial isolates were selected for sequencing. The sequences were used for phylogenetic analysis by MEGA 5. 05 software. From the 20th week of 2009 to the 52nd week of 2011, 17 773 specimens were tested. 3 831 specimens were influenza-positive with a positive rate of 21. 6%, of which 1 794 were positive specimens of pandemic (H1N1) 2009, accounting for 46. 8%00 of the influenza-positives. There were 2 epidemic peaks of pandemic (H1N1) 2009, which were in the 41st-53rd week of 2009 and the 1st-12nd week of 2011, respectively. The HA genes of 23 strains that were selected for sequencing had close relationship; the distribution of strains in the phylogenetic tree was basically in chronological order. The complete genome sequence analysis showed that all of 8 gene segments of 7 strains were homologous to the vaccine strain, and there was no gene reassortment. The HA amino acid sites of the 23 strains were highly similar to the vaccine strain (98. 2% - 100. 0% in homology), but all 23 strains had P83S, S203T and 1321V mutations. The 222 site mutation that may lead to enhanced virulence was found in the A/Hunan/YQ30/2009 strain. The mutation was D222E. There was no oseltamivir resistance mutation found in all strains. The pandemic (H1N1) 2009 in Hunan province from 2009 to 2011 had a bimodal distribution. There was no large-scale variation of virus genes. The clinical use of oseltamivir was still effective. Key words: Pandemic (H1N1) 2009; Surveillance; Genetic characteristics

Adenovirus-mediated bone morphogenetic protein-2 gene transfection of bone marrow mesenchymal stem cells combined with nano-hydroxyapatite to construct bone graft material in vitro

To study the adhesion, proliferation and expression of bone marrow mesenchymal stem cells (BMSCs) on nano-hydroxyapatite (Nano-HA) bone graft material after transfection of adenovirus-mediated human bone morphogenetic protein-2 expression vector (Ad-BMP-2). BMSCs were transfected using Ad-BMP-2. Immunohistochemistry and Western blot were used to detect BMP-2 expression in transfected cells. After transfection, BMP-2 protein was highly expressed in BMSCs; MTT test assay showed that the Nano-HA bone graft material could not inhibit in vitro proliferation of BMSCs. Ad-BMP-2-transfected BMSCs are well biocompatible with Nano-HA bone graft material, the transfected cells in material can secrete BMP-2 stably for a long time.

Interaction of Cd/Zn hyperaccumulating plant (Sedum alfredii) and rhizosphere bacteria on metal uptake and removal of phenanthrene

The effects of bacteria (Burkholderia cepacia) on plant growth, metal uptake, tolerance index and phenanthrene degradation by a hyperaccumulating plant (Sedum alfredii) were investigated. It was found that inoculation of bacteria did not enhance plant growth and metal uptake; while both metal translocation factor (up to 84% for Cd and 42% for Zn) and tolerance index (up to 23.2% for shoot and 72% for root) were significantly increased. In addition, inoculation of bacteria also alleviated the reductions of bioaccumulation factor and phytoextraction efficiency of As, Cu and Zn with the increasing proportions of polluted soil applied, while they were even increased for Cd and Pb (up to 31.2 and 124%, respectively). Up to 96.3% of phenanthrene was removed in the treatment with both plant and bacteria at the end of the experiment. A positive correlation between metal and P accumulation in plants was observed, it is suggested that high P uptake is directly involved in metal detoxification and leading to an increased P requirement. With the assistance of bacteria, S. alfredii could be able to withstand higher metal concentrations and it could also provide a practical tool for phytoremediation.

[Analysis of genetic features of influenza B virus in Hunan province from 2007 to 2010]

OBJECTIVE

To investigate the gene variations of influenza B virus isolated in Hunan province from 2007 to 2010.

METHODS

A total of 42 strains of influenza B virus,which were isolated in the Influenza Surveillance Network Laboratories in Hunan province between year 2007 and 2010, were selected for the study. The hemagglutinin 1 (HA1) and neuraminidase (NA) genes of the selected strains were amplified by RT-PCR, and the sequence of the purified product were detected and homologically compared with the sequence of influenza vaccine strains isolated from Northern Hemisphere by WHO during the same period. In addition, the phylogenetic trees were constructed to characterize the molecular features.

RESULTS

In the Victoria branch of the HA1 gene phylogenetic tree, the strains isolated from year 2007 to 2009 were included in the V1 sub-branch, as well as the vaccine strain Malaysia/2506/2004; the strains isolated in year 2010 were involved in the V2 sub-branch, similar to the vaccine strains Brisbane/60/2008. In the Yamagata branch,the strains isolated in year 2007 were in the Y1 sub-branch,different from the strains isolated between year 2008 and 2010, which were in the Y2 sub-branch, instead. All virus in NA gene phylogenetic tree were included in the Yamagata branch, indicated their Yamagata origin. The genetic sequence analysis of the 7 strains isolated in year 2010 revealed that the viruses were classified as genotype 2 and genotype 15. The results of homological comparison between HA1 molecule and the influenza vaccine strains recommended by WHO were as below: Victoria lineage, 98.6% - 99.1% in 2007, 98.6% - 99.1% in 2008, 98.1% - 99.1% in 2009, and 97.6% - 99.1% in 2010; and Yamagata lineage, 97.9% - 98.5% in 2007, 97.9% - 98.5% in 2009 and 97.9% - 98.2% in 2010. The major mutations of the strains isolated in year 2007 were found in sites R48K, K88R, P108A, D197N and S230G. While the major mutations of the strains isolated between year 2009 and 2010 were sited in K88R, S150I, N166Y, D197N and S230G.

CONCLUSION

The prevalent influenza B virus isolated in Hunan province from 2007 to 2010 has mutated and evolved continuously.

Association between HLA-A and -B polymorphisms and susceptibility to Henoch-Schönlein purpura in Han and Mongolian children from Inner Mongolia

We examined a possible association between HLA-A and -B polymorphisms and susceptibility to Henoch-Schönlein purpura (HSP) in Han and Mongolian children in Inner Mongolia, through a case-control study. Two hundred and sixty-eight unrelated children were enrolled, including 56 Mongolian and 50 Han children with HSP, 66 healthy Mongolian and 96 healthy Han children as a control group. HLA-A and -B alleles were indentified by PCR-sequence-specific oligonucleotide analysis and were further analyzed by PCR-sequencing-based typing (SBT). Frequencies of HLA-A*11, HLA-B*15 in Mongolian patients and HLA-A*26, HLA-B*35, HLA-B*52 in Han patients were higher than those in the corresponding control group (P < 0.05), while frequencies of HLA-B*07 and -B*40 in Mongolian HSP patients were lower than those in the control group (P < 0.05). Further analysis using PCR-SBT showed that all HLA-A*11 were HLA-A*1101, and most HLA-B*15 were HLA-B*1501 in Mongolian HSP patients. All HLA-A*26 were HLA-A*2601 and HLA-B*35 were mostly HLA-B*3503 in Han patients. There were more Han patients with severe manifestations than Mongolian patients (P < 0.05). Frequencies of HLA-A*26, HLA-B*35 and HLA-B*52 in Han patients were higher than in Mongolian patients (P < 0.05). We conclude that HLA-A*11(*1101) and -B*15(*1501) are associated with susceptibility to HSP in Mongolian children and HLA-A*26(*2601), HLA-B*35(*3503) and HLA-B*52 are associated with susceptibility to HSP in Han children. HLA-B*07 and -B*40 may be protective genes in Mongolian children. The different frequencies of HLA-A and -B in Mongolian and Han children may be responsible for the different manifestations in these two ethnic groups.

Advanced phosphorus removal for secondary effluent using a natural treatment system

Mechanisms for low concentrations phosphorus removal in secondary effluent were studied, and a process was developed using limestone filters (LF), submerged macrophyte oxidation ponds (SMOPs) and a subsurface vertical flow wetland (SVFW). Pilot scale experimental models were applied in series to investigate the advanced purification of total phosphorus (TP) in secondary effluent at the Chengjiang sewage treatment plant. With a total hydraulic residence time (HRT) of 82.52 h, the average effluent TP dropped to 0.17 mg L(-1), meeting the standard for Class III surface waters. The major functions of the LF were adsorption and forced precipitation, with a particulate phosphorus (PP) removal of 82.93% and a total dissolved phosphorus (TDP) removal of 41.07%. Oxygen-releasing submerged macrophytes in the SMOPs resulted in maximum dissolved oxygen (DO) and pH values of 11.55 mg L(-1) and 8.10, respectively. This regime provided suitable conditions for chemical precipitation of TDP, which was reduced by a further 39.29%. In the SVFW, TDP was further reduced, and the TP removal in the final effluent reached 85.08%.

[Phosphorus threshold for the shift between grass- and algae-stable states in Dahong Harbor of Gehu Lake]

Taking the macrophytes remaining area in Dahong Harbor of Gehu Lake as test object, this paper studied the phosphorus threshold for the shift between grass- and algae-stable states under natural conditions. The correlation analysis on the environmental factors showed that the total phosphorous in water body had better liner relationships with phytoplankton chlorophyll a and Secchi depth, and principal component analysis indicated that total phosphorous and nitrogen in the water body were the two main components affecting the water quality, among which, total phosphorous was the maximum weight source and played a determinant role in the shift between grass- and algae-stable states. The Harbor was in grass-stable state in winter, shifted to grass-algae intermediate state in spring, and kept the intermediate state in summer and autumn. The total phosphorous threshold for grass-stable state shifting to grass-algae intermediate state was 61 microg x L(-1), and that for grass-algae intermediate state shifting to algae-stable state was 115 microg x L(-1). In order to make the ecosystem shift from algae-stable state to grass-stable state, some measures such as cutting and controlling the Lake's nutrient sources, removing the sediment rich in organic matter, and constructing submerged macrophytes areas should be adopted to make the total phosphorous threshold in the water body dropped to below 61 microg x L(-1).

Trichodermanin A, a novel diterpenoid from endophytic fungus culture

Trichodermanin A, a structurally unique diterpenoid with skeletal carbons arranged compactly in a fused 6-5-6-6 ring system, has been isolated from cultures of Trichoderma atroviride (strain no. S361), an endophytic fungus isolate in Cephalotaxus fortunei. The structure of this compound was elucidated based on extensive spectroscopic methods and confirmed by X-ray diffraction analysis.

[Dynamics model analysis of pollutants removal in aerated vertical-flow wetland]

Based on the dynamic model building of pollutants removal in aerated vertical-flow constructed wetland, data of the wetland under different aeration conditions were analysed. Different aeration conditions' k values were calculated, which represented the pollutants removal kinetic constants. The results demonstrate that the efficiency of pollutants removal is higher with the increasing gas-water ratio. The most favorable designing gas-water ratio of the aerated vertical-flow constructed wetland was chosen as 2 : 1 through analysis of curve fits by regression with kinetic constants values and gas-water ratio values. The corresponding k values of BOD5 and NH4(+) -N are 3.8 d(-1) and 4.1 d(-1) respectively.

Electron microscopy investigations of V defects in multiple InGaN/GaN quantum wells and InGaN quantum dots

The mechanism of high emission of InGaN-based multiple quantum wells, which exhibit exceptionally high light emission efficiency despite their high defect density, is still not fully understood. Here, we deal with this problem, showing the details of structure and formation of V defects in the multiple quantum wells and reviewing interpretations proposed so far. Then, we show a structural investigation of three-dimensional high-density quantum dots, fabricated instead of quantum wells in the active layer. The shape and size of the InGaN quantum dots and the SiN(x) masks for the growth of the dots have been revealed using high-angle annular dark field scanning transmission electron microscopy, energy dispersive X-ray spectroscopy nanoanalysis and high-resolution transmission electron microscopy.

[Comparison of two kinds of procedures used in the removal of horizontal impacted mandibular third molars]

OBJECTIVE

To compare the effect of lingual split bone technique and high speed turbine bodkin boneless technique in the removal of horizontal impacted mandibular third molars.

METHODS

150 horizontal impacted mandibular third molars were randomly divided into two groups, 75 teeth in each group. One group received lingual split bone technique, while the other group received high speed turbine bodkin boneless technique. Both the operation time and operation complication were compared.

RESULTS

The operating time with lingual split bone technique and high speed turbine bodkin boneless technique were (35.85 +/- 6.05) min and (43.52 +/- 7.70) min (P < 0.05), respectively. There was significant difference of intraoperative fracture lingual film removal and facial swelling between lingual split bone technique and high speed turbine bodkin boneless technique (P < 0.05). While there was no significant difference of gingival laceration, postoperative pain, restriction of mouth opening and postoperative bleed between lingual split bone technique and high speed turbine bodkin boneless technique (P > 0.05). There was no lingual nerve injury or numbness of lower lip occurred in two kinds of procedures. Dry socket occurred in a case of high speed turbine bodkin boneless technique.

CONCLUSION

Lingual split bone technique is better in the removal of horizontal impacted mandibular third molars. It could shorten operation time and reduce the intraoperative and postoperative complications.

Effects of different levels of vitamin E on growth performance and immune responses of broilers under heat stress

This experiment was undertaken to evaluate the effect of dietary vitamin E on growth performance and immune response of broilers under heat stress (HS). Birds raised in either a thermoneutral (23.9 degrees C constant) or HS (23.9 to 38 degrees C cycling) environment were fed a corn-soybean meal basal diet supplemented with vitamin E at 0, 100, or 200 mg/kg, respectively. Two hundred forty 1-d-old male broiler chicks were randomly assigned to 6 groups; each group had 4 replicates of 10 birds. Humoral immunity was assessed by i.v. injection of 7% SRBC followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by using a Sephadex stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. Body weight and feed intake were not significantly influenced by dietary vitamin E (P>0.05), whereas feed conversion was significantly affected by vitamin E at 100 mg/kg (P<0.05). Heat stress significantly reduced BW, feed intake, and feed conversion (P<0.05). Numbers of AEC, percentage of macrophages in AEC, phagocytic macrophages, and internalized opsonized and unopsonized SRBC were increased by dietary vitamin E (P<0.05). Both primary and secondary antibody responses were significantly increased by dietary vitamin E when birds were exposed to HS (P<0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC, and phagocytic ability of macrophages were all significantly reduced under HS. These results indicated that HS severely reduced growth performance and immune response of broilers, whereas the immune response of broilers could be improved by dietary vitamin E supplementation under HS.

Development of alum sludge-based constructed wetland: an innovative and cost effective system for wastewater treatment

This article describes a research attempt to integrate the dewatered alum sludge, a residual by-product of drinking water treatment process, into a constructed wetland (CW) system for the purpose of enhancing the wastewater treatment performance, thus developing a so called alum sludge-based constructed wetland system. A multi-dimensional research project including the batch tests of phosphorus (P) adsorption onto alum sludge followed by the model CWs trials of single and multi-stage CWs, has been conducted since 2004. It has been successfully demonstrated that the alum sludge-based CW is capable of enhanced and simultaneous removal of P and organic matter (in terms of BOD5 and COD), particularly from medium and high strength wastewater. The sludge cakes act as the carrier for developing biofilm for organics removal and also serve as adsorbent to enhance P immobilization. Batch P-adsorption tests revealed that the alum sludge tested possesses excellent P-adsorption ability of 14.3 mg-P/g x sludge (in dry solids) at pH 7.0 with the adsorption favored at lower pH. The results obtained in a 4-stage treatment wetland system suggest that high removal efficiencies of 90.4% for COD, 88.0% for BOD5, 90.6% for SS, 76.5% for TN and 91.9% for PO4(3-)-P under hydraulic loading of 0.36 m3/m2 x d can be achieved. The field demonstration study of this pioneering development is now underway.

[Oxygen transfer efficiency of four kinds substrates applied in artificial aeration vertical-flow wetland]

In subsurface flow constructed wetlands, artificial aeration plays an important role in enhancing the ability of pollutant removal. Oxygenation capacity of four substrates, limestone, vesuvianite, 500 grade ceramisite and high-strength ceramisite, are tested under three kinds of gas volume [0.19, 0.38, 0.76 m3 x (m2 x h)(-1)] in artificial aeration vertical-flow wetland. When the gas volume is 0.19 m3 x (m2 x h)(-1), the results demonstrate that the oxygen utilization of 500 grade ceramisite and high-strength ceramisite are highest as 14.39% and 14.21%, and the oxygen utilization of limestone and vesuvianite are 11.68% and 13.11% respectively. With the increase of aeration intensity, oxygen transfer efficiency parameter KLa rises accordingly. However, the oxygen utilization of vesuvianite and two other kinds of ceramisite decreases with the increase of aeration intensity. The oxygen utilization of vesuvianite, 500 grad ceramisite and high-strength ceramisite are lower as 7.67%, 10.46% and 10.77% respectively when the aeration intensity is 0.76 m3 x (m2 x h)(-1). On the contrary, the oxygen utilization of limestone get its maximum value of 14.04% as the aeration intensity is 0.38 m3 x (m2 x h)(-1).

Effects of bacteria on enhanced metal uptake of the Cd/Zn-hyperaccumulating plant, Sedum alfredii

To investigate the effects of bacteria (Burkholderia cepacia) on metal uptake by the hyperaccumulating plant, Sedum alfredii, a hydroponic experiment with different concentrations of Cd and Zn was conducted. It was found that inoculation of bacteria on S. alfredii significantly enhanced plant growth (up to 110% with Zn treatment), P (up to 56.1% with Cd treatment), and metal uptake (up to 243% and 96.3% with Cd and Zn treatment, respectively) in shoots, tolerance index (up to 134% with Zn added treatment), and better translocation of metals (up to 296% and 135% with Cd and Zn treatment, respectively) from root to shoot. In the ampicillin added treatment with metal addition, stimulation of organic acid production (up to an increase of 133% of tartaric acid with Cd treatment) by roots of S. alfredii was observed. The secretion of organic acids appears to be a functional metal resistance mechanism that chelates the metal ions extracellularly, reducing their uptake and subsequent impacts on root physiological processes.

Arsenic uptake and accumulation in fern species growing at arsenic-contaminated sites of southern China: field surveys

Aiming at searching for new arsenic (As) hyperaccumulators, field surveys were conducted at 12 As-contaminated sites located in Guangxi and Guangdong Provinces of southern China. Samples of 24 fern species belonging to 16 genera and 11 families as well as their associated soils were collected and As concentrations in plant and soil samples were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results show that among 24 fern species, Pteris multifida and P. oshimensis can (hyper)accumulate As in their fronds with high concentrations in addition to P. vittata and P. cretica var. nervosa, which have been previously identified as As hyperaccumulators. Total As concentrations in soils associated with P. multifida and P. oshimensis varied from 1262 to 47,235 mg kg(-1), but the DTPA-extractable As concentrations were relatively low, with a maximum of 65 mg kg(-1). Forty-four of 49 samples of P. multifida collected from five sites and 3 of 13 samples of P. oshimensis collected from one site accumulated over 1000 mg As kg(-1) in their fronds and As concentrations in the fronds were higher than those in the petioles and rhizoids. Although As concentrations in the fronds of P. oshimensis (789 mg kg(-1) averaged, range 301-2142 mg kg(-1)) were comparatively lower than those of P. multifida (1977 mg kg9-1), 624-4056 mg kg(-1)), its high aboveground biomass makes it more suitable for phytoremediating As-contaminated soils. Among all the species in Pteris genus studied, Pteris semipinnata accumulated only very low As concentration in its fronds (8 mg kg(-1), 1-18 mg kg(-1)). Further research is needed to study the differences in As uptake and accumulation among fern species in the same or other genera.

Defining classes of spinal interneuron and their axonal projections in hatchling Xenopus laevis tadpoles

Neurobiotin was injected into individual spinal interneurons in the Xenopus tadpole to discern their anatomical features and complete axonal projection patterns. Four classes of interneuron are described, with names defining their primary axon projection: Dorsolateral ascending and commissural interneurons are predominantly multipolar cells with somata and dendrites exclusively in the dorsal half of the spinal cord. Ascending interneurons have unipolar somata located in the dorsal half, but their main dendrites are located in the ventral half of the spinal cord. Descending interneurons show bigger variance in their anatomy, but the majority are unipolar, and they all have a descending primary axon. Dorsolateral commissural interneurons are clearly defined using established criteria, but the others are not, so cluster analysis was used. Clear discriminations can be made, and criteria are established to characterize the three classes of interneuron with ipsilateral axonal projections. With identifying criteria established, the distribution and axonal projection patterns of the four classes of interneuron are described. By using data from gamma-aminobutyric acid immunocytochemistry, the distribution of the population of ascending interneurons is defined. Together with the results from the axonal projection data, this allows the ascending interneuron axon distribution along the spinal cord to be estimated. By making simple assumptions and using existing information about the soma distributions of the other interneurons, estimates of their axon distributions are made. The possible functional roles of the four interneuron classes are discussed.

Different management options for anaphylactoid purpura with intussusception: a case report

Intussusception is the most common surgical indication of anaphylactoid purpura. About 50% of cases are of the ileo-ileal type. Surgical intervention, rather than radiologic reduction, is preferable for older children suffering from anaphylactoid purpura with intussusception, where a lead point lesion is often found. The authors report a case of anaphylactoid purpura with intussusception with spontaneous reduction, and postulate that subsequent to relieving bowel-wall edema using antihistamine and steroid therapy, the ileo-ileal intussusception may spontaneously reduce.

Pathogens in the middle ear effusion of children with persistent otitis media: implications of drug resistance and complications

Acute otitis media (AOM) is the most common disease for which pediatricians prescribe antimicrobial agents. Middle ear fluid were collected from 243 children with AOM that failed to respond to a previous course of antimicrobial therapy and who had then received myringotomy from September 1997 through August 1999. Bacterial cultures were done and antimicrobial susceptibilities were analyzed. Streptococcus pneumoniae (21.8%) was the most common causative organism, followed by Haemophilus influenzae (10.2%), Staphylococcus aureus (7%), and Pseudomonas aeruginosa (1.8%), while Moraxella catarrhalis (0.7%) and group A beta-hemolytic streptococcus (0.2%) were rarely isolated. In patients whose condition failed to improve after a course of antibiotic treatment, drug resistance became a serious problem. Fourteen percent of the patients in this series had complications, which included recurrent AOM, persistent middle ear effusion necessitating ventilation tube insertion, hearing impairment, mastoiditis, meningitis, chronic otitis media, brain abscess, and sepsis. Possible risk factors such as young age, male sex, underlying diseases, and a culture of S. pneumoniae or H. influenzae were not significantly associated with an increased incidence of complications. More stringent diagnosis and the correct choice of antibiotic treatment combined with the introduction of potential virus and bacterial vaccines are promising ways to reduce the morbidity of AOM in children.

Characteristics of neonatal bacterial meningitis in a teaching hospital in Taiwan from 1984-1997

During the period from 1984 to 1997, 85 bacterial meningitis neonates with positive cerebrospinal fluid cultures were treated. The ages of these patients ranged from 1 to 28 days. The male to female ratio was 1.7 to 1. The most common causative agent was group B beta-hemolytic streptococci (GBS, 31.8%), followed by Escherichia coli (20%), Proteus mirabilis (7.1%), Enterobacter cloacae (5.9%), other streptococci excluding Streptococcus pneumoniae (5.9%), Chryseobacterium meningosepticum (5.9%), enterococci (4.7%), and Klebsiella pneumoniae (3.5%). Among the 85 patients treated, 51 (60%) were younger than 7 days old. Among them, dyspnea was the most common clinical manifestation. In contrast, fever and diarrhea were seen more frequently in neonates with late onset of disease (after seven days of age). Ampicillin and cefotaxime were the most commonly used antibiotics. The most frequently encountered complications were hydrocephalus and seizures. Since 1991, GBS has overtaken E. coli as the leading cause of neonatal bacterial meningitis. This was accompanied by a fall in the mortality rate, but a sustained high incidence of complications and sequelae. The results of this study highlight the importance of developing strategies to prevent group B streptococcal infection.

Water clusters in life

The role of water in chemical, biochemical and cellular events has only been recognized as a universal solvent. The conventional wisdom holds that water is a passive agent in biological interaction. However, more and more researchers regard water as an active component in biochemical reactions and hence occupy a crucial role in life. We propose that the active component of water is due to the existence of stable water clusters in aqueous solutions. Our research demonstrated that stable water clusters could be produced in very dilute inorganic and organic water solutions, and also isolated from biological fluids such as bovine serum. Stable water clusters may play an important role in physiological and pathological processes of life.

Electrical interaction between neurons in the pigeon isthmo-optic nucleus

The present study used brain slices to investigate interneuronal communication in the isthmo-optic nucleus in pigeons. Electrical stimulation of the isthmo-optic tract generated a transmembrane potential in isthmo-optic cells that was obtained by subtracting the extracellular potential from the intracellular potential. This transmembrane potential resulted in enhancement of excitability and/or in production of spikes in 42 (63%) cells. In most cases, proximal axons marked in brain slices by Lucifer yellow were too short to reach the stimulation site, indicating that spikes were evoked by electrical field effect or ephaptic interaction produced by nearby cells whose axons were activated by stimulation. Eleven (16%) cells discharged a spikelet, or spike that was abolished by hyperpolarizing current injection leaving a spikelet. Markings of five of these cells all indicated the presence of dye-couplings, each of which consisted of a pair of cells. Fourteen (21%) cells only produced antidromic spikes with a short and constant latency. Four of these cells were marked and their axons passed through the stimulation site, implying that their nearby cells' axons might be cut too short to be electrically stimulated or they were in a sparse-cell area. The present results provide electrophysiological and neuroanatomical evidence that both electrical field effect and electrical coupling may play important roles in interneuronal communication within the pigeon isthmo-optic nucleus. These findings are supported by anatomical arrangement of densely packed cells and their oriented dendrites in this centrifugal nucleus.

Characterization of group D1 non-typhoid Salmonella isolates by serotyping and pulsed field gel electrophoresis

Non-typhoid salmonella infection is not uncommon in immunocompetent patients in Taiwan. Bacterial factors may play an important role in the pathogenesis of such infections. In a previous study, Salmonella group D1 was found to have the tendency to cause bacteremia with a higher frequency than other serotypes. In the present study, we prospectively collected 94 Salmonella group D1 isolates for serotyping and molecular typing. Salmonella panama and Salmonella dublin seemed more invasive than other serotypes. Pulsed field gel electrophoresis was also done to characterize of Salmonella enteritidis and Salmonella dublin. PFGE type "a" of Salmonella dublin appeared to be more invasive than the other two PFGE types. All six Salmonella dublin isolates were Vi antigen negative. Further study using a larger number of isolates is needed to identify the tendency to invade blood stream of Salmonella dublin and Salmonella panama.

Evaluation of an alternative to the Kolmogorov-Smirnov test for flow cytometric histogram comparisons

BACKGROUND

The Kolmogorov-Smirnov test is a valid statistical test for comparing distributions that has been recommended for flow cytometric histogram analysis. However, this test is frequently found to be too sensitive for flow cytometric histogram comparisons. Here, a parametric alternative to the Kolmogorov-Smirnov test is proposed that is based on fitting suitable models to flow cytometric data.

METHODS

Several flow cytometric histograms derived from cell surface immunophenotyping for intercellular adhesion molecule-1 (ICAM-1) on K562 cells were analyzed using numerical modeling. The prediction intervals derived from the modeling were used for decision making.

RESULTS

The residuals after peak fitting flow cytometric data are normally distributed and this permits the use of the prediction limit methodology. The usefulness of the approach for analyzing flow cytometry histograms is examined and the method is shown to avoid the "sensitivity" disadvantages associated with the Kolmogorov-Smirnov test.

CONCLUSIONS

The prediction limit method is a viable alternative to the Kolmogorov-Smirnov method.

[Gap junctions in the nervous tissue]

In recent years, prominent progresses have been made in the study of the localization and function of gap junctions in the nervous tissue. The application of molecular approaches has advanced the disclosure of the structure, classification and biophysical properties of gap junctions. Dye-coupling and Ca2+ imaging techniques have provided explicit and effective ways for the study of gap junctional functions. The regulation of gap junctions involves the expression of gap junction genes and changes in the conductivity of gap junction channels. Gap junctional intercellular communication includes the exchange of second-messengers and electrical coupling between coupled cells. GJ plays an important role in the function of neuroglial cells, neurons in some brain regions and probably in the formation of local neuronal circuits.

Dual actions of isthmic input to tectal neurons in a reptile, Gekko gekko

We analyzed postsynaptic potentials and dye-labeled morphology of tectal neurons responding to electrical stimulation of the optic nerve and of the nucleus isthmi in a reptile, Gekko gekko, in order to compare with previously reported interactions between the optic tectum and the nucleus isthmi in amphibians and birds. The results indicate that isthmic stimulation exerts inhibitory and excitatory actions on tectal cells, similar to dual isthmotectal actions in amphibians. It appears that dual actions of the isthmotectal pathway in amphibians and reptiles are shared by two subdivisions of the nucleus isthmi in birds. The morphology of tectal cells responding to isthmic stimulation is generally similar to that of tectoisthmic projecting neurons, but they differ particularly in that some tectoisthmic cells bear numerous varicosities whereas cells receiving isthmic afferents do not. Thus, it is likely that at least some tectoisthmic cells may not be in the population of tectal cells that can be affected by isthmic stimulation. Forty-four percent of injections resulted in dye-coupled labeling, suggesting extensive electrical connections between tectal cells in reptiles.

The effect of deprivation on child health in Bro Taf

Infant mortality rate (IMR) and disability indices were compared in 16 y birth cohorts (1979-1994) inclusive) from two neighbouring but contrasting boroughs in Bro Taf. The comparison was extended to children with mild learning difficulties. Children with and without learning problems were compared for birth weight (BW). Further data on infant mortality by cause of death, BW and maternal age were analysed for 6 y within this period (all births from 1979-1984 inclusive). The more deprived area had a higher IMR and a greater number of deaths attributed to low birth weight. It had a higher rate of childhood disability which was due to a higher rate of moderate learning disabilities. There was also a higher rate of mild learning difficulty. Learning problems were associated with low birth weight. The more deprived area had a greater proportion of low birth weight and very low birth weight babies and more mothers who were in their teens and early teens.

Tectal afferents monosynaptically activate neurons in the pigeon isthmo-optic nucleus

Postsynaptic responses of 105 neurons in brain slices were intracellularly recorded from the isthmo-optic nucleus (ION) in pigeons, and 18 of these neurons were labeled with Lucifer yellow. Excitatory postsynaptic potentials (EPSPs) or spikes were produced in 93 cells, inhibitory postsynaptic potentials (IPSPs) in 10 cells, and EPSPs followed by IPSPs in two cells following electrical stimulation of the tecto-isthmooptic tract. The EPSPs occurred in an all-or-none fashion, with short latencies (1.3 +/- 0.6 ms). Repetitive stimulation increased their amplitude and duration, demonstrating that temporal summation was involved. Neurons producing excitatory responses were distributed throughout cellular layers of the nucleus. Pure IPSPs had a latency of 3.9 +/- 2.3 ms, and cells that responded in this manner were only distributed in the rostral portion of the nucleus. In the remaining two cells with EPSP-IPSP responses, the latency of excitatory responses was 1.5 ms in one cell and 1.4 ms in the other, and that of inhibitory responses was, respectively, 5.1 and 4.1 ms. Thus, it appeared that excitation was monosynaptic, whereas inhibition may be polysynaptic. Four single injections resulted in dye-coupled labeling, and two pairs of closely apposed cells fired spikes, probably resulting from spatial summation of their excitatory responses. The present study suggests that tectal cells directly activate ION neurons and that tectal fibers contact isthmo-optic neurons in a one-to-one fashion. Taken together with previous studies, it appears that the entire tecto-ION-retinal pathway is excitatory.

Histamine excites rat cerebellar granule cells in vitro through H1 and H2 receptors

The effects of histamine on the firing of cerebellar granule cells were investigated in vitro. Histamine predominantly produced excitatory (117/123, 95.1%) and in a few cases inhibitory (6/123, 4.9%) responses in granule cells. The histamine-induced excitation was not blocked by perfusing the slice with low Ca2+/high Mg2+ medium, supporting a direct postsynaptic action of histamine. The H1 receptor antagonists triprolidine and chlorpheniramine significantly diminished the histamine-induced excitation, but the H2 receptor antagonist ranitidine did not significantly reduce the excitation. On the other hand, the H2 receptor agonist dimaprit could elicit a weak excitation of granule cells. This dimaprit-induced excitation was blocked by ranitidine but not triprolidine. These results reveal that the excitatory effect of histamine on cerebellar granule cells is mediated by both H1 and H2 receptors with a predominant contribution of H1 receptors. The relevance of these findings to the possible function of the hypothalamocerebellar histaminergic fibers in cerebellum is discussed.

Differential expression of the two duplicated insecticyanin genes, ins-a and ins-b, in the black mutant of Manduca sexta

The black (bl) mutant larvae of Manduca sexta produces no detectable juvenile hormone (JH) during the molt to the 5th instar. To investigate the JH control of expression of the two insecticyanin genes, ins-a and ins-b, developmental changes of the two mRNAs were examined in this mutant. In the epidermis of the freshly ecdysed larvae, the two mRNAs were hardly detectable. Twelve hours after ecdysis, the two mRNAs appeared in low levels and were then gradually increased with ins-a mRNA rising to a plateau from Day 1 to Day 2 morning and ins-b mRNA in Day 2. During these early developmental stages, the epidermal level of the two mRNAs in the bl mutant was substantially lower than that observed in the wild-type larvae. On Day 3 of the 5th instar when the larval epidermis becomes pupally committed, the two mRNAs in both bl mutant and wild-type larvae show a similar differential expression pattern. In the fat body, the level of both ins-a and ins-b mRNAs was higher than that found in the wild-type larvae. Exogenous JH almost restores the level of the two mRNAs in both epidermis and fat body of the Day 0 5th-instar bl mutant larvae to that observed in wild-type animals of the same stage. These results suggest that JH may enhance expression of the two insecticyanin genes in the epidermis but partially repress their expression in the fat body during early development of the wild-type 5th-instar larvae.

Variation in cellular glutathione peroxidase activity in lens epithelial cells, transgenics and knockouts does not significantly change the response to H2O2 stress

This investigation examines the contribution of glutathione peroxidase (GSHPx-1) in degrading H2O2 in lens preparations. Rabbit (N/N1003A) and normal and GSHPx-1 transfected mouse (alpha TN4-1) lens epithelial cell lines and normal and GSHPx-1 transgenic and knockout mouse lenses were utilized. GSHPx-1 activity in the cell lines was increased from two-fold to about four-fold, in the lenses from transgenics more than four-fold and the lenses from knockouts had less than 3% of normal GSHPx-1 activity. The transgenic and knockout mice as well as their lenses appeared normal for up to 3 to 4 months, the longest period of observation. The preparations were subjected to oxidative stress by placing them either in a medium containing 120 or 300 microM H2O2 or utilizing photochemical stress where the H2O2 levels normally rise to about 100 microM over a few hours in the presence of a normal lens. With all preparations, it was found that either markedly increasing or eliminating GSHPx-1 activity had only a small effect on the system's ability to metabolize H2O2, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), an inhibitor of GSSG reductase (GSSG Red) and 3-aminotriazole (3-AT), an inhibitor of catalase, also had little effect. However, the addition of both inhibitors caused a marked decrease in H2O2 degradation. Examination of the distribution of GSHPx-1 in the lens indicated that the activity per milligram of protein was evenly distributed between the epithelium and the remainder of the lens in the normal lens and was about 1.7-fold greater in the epithelium of transgenic lenses than in the remainder of the lens. Surprisingly, the distribution of GSSG Red was quite different with eight- to ten-fold more activity in the epithelium. Catalase was also found to be concentrated in the epithelium. With H2O2 exposure, a rapid loss of non-protein thiol (NP-thiol) was found in cell cultures and in the epithelia of cultured lenses. However, the remainder of the lens showed little change in NP-thiol. The variation of GSHPx-1 activity did not influence the NP-thiol changes which occurred more rapidly and to a greater extent in the presence of BCNU. The addition of BCNU also caused a decrease in total lens NP-thiol. Examination of thymidine incorporation and choline transport, indicators of nuclear and membrane function, also reflects the H2O2 degradation data, showing little difference in the degree to which H2O2 effects these parameters in lenses from normal and transgenic animals. Catalase activity is four- to six-fold greater than GSHPX-1 activity in the alpha TN4-1 cell lines, about three-fold lower in the rabbit cell line and, remarkably, about 18-fold lower than the peroxidase in the normal mouse lens. In spite of such observations, the consistent overall conclusion is that GSHPx-1 and catalase function together but when GSHPx-1 is knocked out or GSSG Red is inhibited, catalase is able to protect the system from H2O2 stress. Indeed, the young mouse does not appear to require GSH Px-1 for normal function.

Lens epithelial cell apoptosis is an early event in the development of UVB-induced cataract

Epidemiological and experimental studies have revealed that exposure to UV can induce cataractogenesis. To investigate the mechanism of this induction, viability of the lens epithelial cells from UVB-treated rat lenses were examined. Irradiation of the cultured rat lenses with 8 J/s/m2 UVB for 60 min triggers lens epithelial cell apoptosis as determined by terminal deoxyribonucleotide transferase (TdT) labeling and DNA fragmentation assays. The apoptotic lens epithelial cells were initially found in the equatorial region and then quickly appeared in both equatorial and central regions. The percentage of apoptotic cells continuously increased during the postirradiation incubation. After a 5-h post-UVB incubation, more than 50% of the lens epithelial cells were apoptotic. By 24 h, all of the lens epithelial cells in the irradiated lenses were dead through apoptosis. Associated with this apoptotic process is a large upregulation of the proto-oncogene, c-fos. Opacification appears to follow the death of lens epithelial cells occurring first in the equatorial region and then in the central area. This is also true of classical cataract parameters such as non-protein thiol and wet weight, which are significantly modified only after appreciable epithelial cell apoptosis. Together, these results suggest that the rapid apoptotic death of the lens epithelial cells induced by UVB initiates cataract development.

Calcimycin-induced lens epithelial cell apoptosis contributes to cataract formation

Previous studies have shown that calcimycin induces cataract in organ culture. To investigate the mechanism of this induction, the viability of lens epithelial cells in calcimycin (calcium ionophore, A23187)-treated rat lenses were examined. During incubation of lenses with 5 microM calcimycin, apoptotic epithelial cells were found after a 2-hr treatment as determined by terminal deoxynucleotidyl transferase (TdT) labeling. The percentage of apoptotic cells quickly rose as the incubation time increased. After a 12-hr incubation, more than 60% of the lens epithelial cells underwent apoptosis. Prolonged c-fos expression, previously shown to be an indicator of programmed cell death, was also observed during this treatment. DNA fragmentation assays further confirmed that the TdT labeled cells were indeed apoptotic. Under the same incubation conditions, the cultured lenses gradually lost transparency and became completely opaque in about 30 hr. Since the vertebrate lens contains only a single layer of epithelial cells, apoptotic death of these cells activated by calcimycin quickly destroys the lens epithelium, impairs homeostasis of the underlying fiber cells and initiates development of lens opacification.

Lens epithelial cell apoptosis appears to be a common cellular basis for non-congenital cataract development in humans and animals

Cataract is a major ocular disease that causes blindness in many developing countries of the world. It is well established that various factors such as oxidative stress, UV, and other toxic agents can induce both in vivo and in vitro cataract formation. However, a common cellular basis for this induction has not been previously recognized. The present study of lens epithelial cell viability suggests such a general mechanism. When lens epithelial cells from a group of 20 cataract patients 12 to 94 years old were analyzed by terminal deoxynucleotidyl transferase (TdT) labeling and DNA fragmentation assays, it was found that all of these patients had apoptotic epithelial cells ranging from 4.4 to 41.8%. By contrast, in eight normal human lenses of comparable age, very few apoptotic epithelial cells were observed. We suggest that cataract patients may have deficient defense systems against factors such as oxidative stress and UV at the onset of the disease. Such stress can trigger lens epithelial cell apoptosis that then may initiate cataract development. To test this hypothesis, it is also demonstrated here that hydrogen peroxide at concentrations previously found in some cataract patients induces both lens epithelial cell apoptosis and cortical opacity. Moreover, the temporal and spatial distribution of induced apoptotic lens epithelial cells precedes development of lens opacification. These results suggest that lens epithelial cell apoptosis may be a common cellular basis for initiation of noncongenital cataract formation.

A brief photochemically induced oxidative insult causes irreversible lens damage and cataract. I. Transparency and epithelial cell layer

Short-term photochemical insult of cultured rat lenses caused by the generation of H2O2, O2<--and OH. was found to lead to rapid irreversible damage to the epithelial cell layer. This irreversible damage was measured by Trypan blue staining, terminal deoxyribonucleotidyl transferase labeling, DNA laddering and morphological analyses. There appears to be an inverse relationship between the period of photochemical insult and the post-insult time required to observe epithelial cell damage. Insulting periods of a few hours require post-insult intervals of days to observe significant cell damage and weeks before complete cortical cataracts are found. Epithelial cell damage precedes the loss of transparency.

A brief photochemically induced oxidative insult causes irreversible lens damage and cataract. II. Mechanism of action

Using photochemically induced oxidative stress and rat lenses in organ culture with 4% O2 and 4 microM riboflavin, it has been found that the observed changes in lens parameters are, in most cases, irreversible. This has made possible the elucidation of the sequence of biological changes leading to cataract. The earliest detectable changes in lens cell biology are observed in the epithelial cell redox set point and at the DNA level in terms of DNA integrity and 3H-thymidine incorporation followed by decreased membrane transport and changes in gene expression. Significant modification in classical cataract parameters such as hydration, steady state non-protein thiol, glyceraldehyde-phosphate-dehydrogenase activity and transparency occur at later times. The data suggest a definitive pattern of lens breakdown resulting in opacity starting at the epithelial cell level and leading to subsequent fibre cell involvement.

The two duplicated insecticyanin genes, ins-a and ins-b are differentially expressed in the tobacco hornworm, Manduca sexta

Two gene-specific probes were generated from the unique sequences in the 3' non-coding regions of the two insecticyanin genes, ins-a and ins-b to study the developmental expression of these genes in Manduca sexta. Both genes were initially transcribed in the freshly hatched first instar larvae and then expressed in the epidermis and to a lesser degree in the fat body during every larval feeding stage. In the epidermis of the 4th and 5th instar larvae, both mRNAs appeared shortly before ecdysis and accumulated to maximal levels within a day. As the larval epidermis became pupally committed on day 3 of the 5th (final) instar, INS-a mRNA quickly decreased, whereas INS-b mRNA showed a second peak of accumulation. In the fat body, both genes showed a similar expression pattern within the 4th instar to that of the epidermis except that levels were lower and ins-b mRNA dominated. In the final instar, only ins-b mRNA was present in significant amount. These findings not only reveal that the two duplicated insecticyanin genes have diverged in their expression pattern but also demonstrate, for the first time, that fat body also expresses insecticyanin genes.

The redox active components H2O2 and N-acetyl-L-cysteine regulate expression of c-jun and c-fos in lens systems

Hydrogen peroxide (H2O2) is implicated in human cataract development. At the molecular level H2O2 has been observed to cause damage to DNA, protein and lipid. It is now demonstrated, for the first time in a lens system, that H2O2 at concentrations found in cataract patients induces expression of both c-jun and c-fos. At optimal concentrations of H2O2, mRNA accumulation of c-jun and c-fos in the rat lenses is induced 20- and 18-fold above normal levels respectively, but with distinct kinetics. This induction occurs at the transcriptional level. H2O2 also induces transactivation by activating protein-1 (AP-1) in rabbit lens epithelial cells. The antioxidant N-acetyl-cysteine (NAC) has a dual effect on the induction of c-jun and c-fos. Preincubation of rat lenses with 5 mM NAC inhibits the induction by H2O2, while 30 mM and 50 mM NAC induce expression of these genes and mask the H2O2 effect. H7 (50 microM), genistein (2 microM) and okadaic acid (20 nM), all block the induction of c-jun and c-fos mRNA accumulation in the H2O2-treated rat lenses. These results suggest that H2O2 activates protein kinase and phosphatase dependent signal transduction pathways to induce c-jun and c-fos expression which may regulate lens crystallin genes and other genes containing AP-1 binding sites.