The effect of mindfulness-based interventions on reducing stress in future health professionals: A systematic review and meta-analysis of randomized controlled trials

Students in health professions often face high levels of stress due to demanding academic schedules, heavy workloads, disrupted work-life balance, and sleep deprivation. Addressing stress during their education can prevent negative consequences for their mental health and the well-being of their future patients. Previous reviews on the effectiveness of mindfulness-based interventions (MBIs) focused on working health professionals or included a wide range of intervention types and durations. This study aims to investigate the effect of 6- to 12-week MBIs with 1- to 2-h weekly sessions on stress in future health professionals. We conducted a systematic review and meta-analysis of randomized controlled trials published in English by searching Embase, Medline, Web of Science, Cochrane Central Register of Controlled Trials, and PsycINFO. We used post-intervention stress levels and standard deviations to assess the ability of MBIs to reduce stress, summarized by the standardized mean difference (SMD). This review is reported according to the PRISMA checklist (2020). We identified 2932 studies, of which 11 were included in the systematic review and 10 had sufficient data for inclusion in the meta-analysis. The overall effect of MBIs on reducing stress was a SMD of 0.60 (95% CI [0.27, 0.94]). Our study provides evidence that MBIs have a moderate reducing effect on stress in students in health professions; however, given the high risk of bias, these findings should be interpreted with caution, and further high-quality studies are needed.

[Comparison between computer aided simulation and dental model orthognathic surgery for the treatment of patients with mandibular excess and facial asymmetries]

Objective: To evaluate the results of the orthognathic surgery with computer aided simulation-three-dimensional(3D) printed surgical guide and dental model surgery in the treatmemt of patients with mandibular excess and facial asymmetries. Methods: The coordinate system was built in ProPlan CMF 2.0 software, and the horizontal plane consisted of PoL, PoR, OrL, middle sagittal plane through nasion point and basion point and the plane perpendicular to the horizontal plane, coronoid plane through nasion point and the plane perpendicular to the horizontal plane and middle sagittal plane. The orientation of maxilla and mandibular distal segment was calculated by each triangle(U1-U6L-U6R, L1-L6L-L6R, Me-M5L-M5R) before and after orthognathic surgery. A total of 60 mandibular excess patients with facial asymmetries were enrolled in this retrospective study. They were divided into two groups, group Ⅰ with computer aided simulation, group Ⅱ with dental model surgery. The difference of maxillary occlusal plane roll and yaw angle, mandibular occlusal plane roll and yaw angle, and mandibular body plane roll and yaw angle were calculated. Statistical analysis was performed with SPSS 17.0 software. Results: The yaw angle of mandibular occlusal plane of the dental model surgery and computer aided simulation was 0.36°± 0.48° and 0.84° ± 0.36° (P=0.043), respectively. The roll angle of mandibular occlusal plane of the dental model surgery and computer aided simulation was 0.26°±0.79° and 0.54°±0.40°(P=0.032), respectively. The yaw angle of mandibular body plane of the dental model surgery and computer aided simulation was 0.60°± 1.04° and 0.23°±0.52°(P=0.008), respectively. The roll angle of mandibular body plane of the dental model surgery and computer aided simulation was 0.82° ± 0.72° and 0.53° ± 0.37° (P=0.028), respectively. The changes in computer aided simulation group were more obvious than that in the dental model surgery group, but the difference was not significant in the yaw angle of maxillary occlusal plane and the roll angle of maxillary occlusal plane between the two groups(P >0.05). Conclusions: It was more effective to correct mandibular asymmetry by computer aided simulation than dental model surgery.

Effect of oral immunization with Aeromonas hydrophila ghosts on protection against experimental fish infection

AIMS

To investigate whether oral immunization with Aeromonas hydrophila ghosts (AHG) vaccine can elicit mucosal and systemic immune responses of Carp (Carassius auratus gibelio) compared to conventional formalin-killed bacteria (FKC).

METHODS AND RESULTS

Fish were fed diets coated with AHG, FKC or phosphate buffered saline (PBS) alone, after immunization, more antigen-specific antibody was significantly detected in serum and intestinal mucus in AHG group than FKC group and PBS group. In addition, after challenged with the parent strain J-1, the survival of bacterial ghost-vaccinated fish was higher than PBS group and FKC group, the relative per cent survival (RPS) being 76.8%, 58.9%, respectively.

CONCLUSIONS

Oral immunization with A. hydrophila ghosts can elicit systemic and mucosal adaptive immune responses and has higher potential to induce protective adaptive immunity than normal vaccine.

SIGNIFICANCE AND IMPACT OF THE STUDY

Oral immunization with bacterial ghosts is a promising new solution with potential application to prevent diseases in fish.

[Lysogenic infection of a Shiga toxin 2-converting bacteriophage changes host gene expression, enhances host acid resistance and motility]

Shiga toxin 2 (Stx2)-converting bacteriophages can infect and lysogenize other bacteria in vivo and in vitro, and, thus, contribute to a genotypic heterogeneity of infected host. However, the global transcription patterns accompanying the lysogenic infection of E. coli host have not been clearly resolved. In this study, gene expression profiles of Stx2 phage phi Min27(delta stx::cat) converted and native E. coli MG1655 hosts were compared using microarray assay. The phi Min27(delta stx::cat) conversion had a direct effect on the global expression of bacterial host genes as 166 genes were found to be differentially expressed (104 up-regulated and 62 downregulated). These genes were predominantly responsible for bacterial central metabolism, transport and transcription. It was shown that in addition to the down-regulation of genes involved in synthesis of thiamine and protein transporters, expression of genes associated with bacterial energy production (e.g., fadABDEHIJL, aceK, and acnA) was also suppressed. Conversely, most up-regulated genes were transport genes, flagellar synthesis genes (fliDESTZ), and acid resistance genes (e.g., gadEW, hdeABD, and adiY). Futhermore, conversion of phi Min27(delta stx::cat) was shown to change physiological properties of the host cell. In comparison with the uninfected cells the converted bacteria host had increased acid tolerance and promoted swimming motility on a semisolid agar surface.

Analysis of putative recombination hot sites in the S gene of canine coronaviruses

The S gene sequence of Canine coronavirus strain 1-71 (CCoV 1-71) was cloned, sequenced, and compared to those of other CCoVs, Transmissible gastroenteritis virus (TGEV), and Feline coronavirus (FCoV). The sequence analysis showed that CCoV 1-71 displayed a 98.8-99.8% identity with CCoVs strains V1, K378, and GP. Four putative recombination sites were found at the 5'-end of the S gene, namely at nt 53, 75, 425, 991. Both sequences flanking each site were significantly different. Three recombination hot regions were found on the S gene, namely at nt 337-437, 1545-3405, and 4203-4356, which shared a common recombination signal with Group 2 coronaviruses. The G/CTAAAAA/GT sequence downstream of the recombination site may represent a specific recombination signal in CCoVs. The CCoV 1-71 S protein sequence was found to be similar to those of other CCoVs except for several N-glycosylation sites at the N-terminus of the S protein, which could be related to the differences in virulence and cell tropism in individual CCoVs. This study indicated that the similarity of CCoVs in virulence and tropism was mostly acquired by the homologous RNA recombination and not only by simple mutation and selection.

Purified recombinant phage lysin LySMP: an extensive spectrum of lytic activity for swine streptococci

Bacteriophage lysin has attracted considerable attentions as possible antimicrobial agents for solution of antibiotic resistance. SMP was a Streptococcus suis serotype 2 bacteriophage isolated from nasal swabs of healthy Bama minipigs. The putative SMP bacteriophage lysin, designated LySMP, was recombinantly expressed in Escherichia coli BL21, and chromatographically purified. Treated with 0.8% of beta-mercaptoethanol, LySMP exhibited an extensive lysin spectrum than those of whole phage against bacteria investigated. S. suis serotype 2, S. suis serotype 7 and S. suis serotype 9 strains were recovered from diseased pigs between 1998 and 2005 in China. Fifteen of seventeen strains of S. suis serotype 2 could be lysed, as well as S. suis serotype 7 and 9, Streptococcus equi ssp. zooepidemicus and Staphylococcus aureus. But E. coli and Salmonella enterica were not affected. Purified LySMP showed high degrading efficiency against PMSF or lysozyme treated cells comparing to PBS washed cells. Optimum pH and temperature conditions for the lysin were investigated by turbidity reduction assay. The lysin exerted efficient lysis activity at 37 degrees C, pH 5.2. The turbidity of bacterium investigated was observed to decrease by 1.2-68% in 30 min. Result indicated that putative LySMP could be a candidate antimicrobial agent in controlling S. suis infection.

Immunoproteomic Assay of Membrane-associated Proteins of Streptococcus suis Type 2 China Vaccine Strain HA9801

Immunoproteomic approaches were undertaken to study the immunogenicity of the membrane-associated proteins of the Streptococcus suis type 2 (SS2) China vaccine strain HA9801. The membrane-associated proteins were enriched using the Triton X-114 extraction protocol and were analysed by two-dimensional gel electrophoresis (2-DE) and subsequent immunoblotting using the hyperimmune serum of SS2-HA9801-immunized specific pathogen free (SPF) minipigs. A total of 11 proteins were recognized, and the corresponding spots on a duplicate gel were excised and identified by MALDI-TOF MS.

Comparison of four infectious bursal disease viruses isolated from different bird species

Four isolates of infectious bursal disease virus (IBDV), isolated from chicken, duck, goose and sparrow in Jiangsu province of China in 2002, were compared. The viruses were stable to the treatments of 60 degrees C for 1 h, pH 2.0 and lipid solvents. Their antigenic relatedness values (R) were from 0.76 to 0.78. Chickens infected with the chicken isolate showed severe clinical symptoms of IBD and the mortality rate was 33.3% (2/6). Chickens infected with the other three viruses survived but their bursas were damaged and the bursa/body-weight ratios were lower than those of the uninfected control (p< 0.01). The titers of anti-IBDV antibody in infected chicken sera reached up to 1600 by virus neutralization and 6400 by ELISA at 10 days post infection. The sequences of the variable region of VP2 were aligned and compared, showing nucleotide variations ranging from 1.5 to 6.7% and deduced aminoacid variations from 0.8 to 2.2%. All had the same heptapeptide, S-W-S-A-S-G-S, Asp279, and Ala284. The four viruses clustered on a phylogenetic tree and were distant from the STC strain. These findings suggested that different bird species naturally infected with IBDV could serve as carriers or reservoirs in IBDV transmission and might play a role in the emergence of variant IBDV.

Contribution of AhyR to virulence of Aeromonas hydrophila J-1

Aeromonas hydrophila is a broad-host-range pathogen and its pathogenesis is multifactorial. A regulatory mechanism known as quorum sensing has been found to be involved in the regulation of virulence in many bacteria. In A. hydrophila the ahyR gene encodes LuxR-type response regulator. Here we describe the inactivation of the ahyR gene of A. hydrophila J-1 by the insertion of a DNA fragment containing a kanamycin resistance determinant and reintroduced by allelic exchange into the chromosome of A. hydrophila J-1 by means of the suicide plasmid pJP5603. Cytotoxic effects on EPC cells assay and LD(50) determinations in fish demonstrated that the ahyR mutant was highly attenuated relative to the wild-type strain. Compared with the parent strain, some characteristics, such as biochemical characters and outer membrane protein profiles, had changed. Some main virulent determinants could not be detected, including proteases, amylase, Dnase, hemolysin and S layer. This article confirmed the important function of AhyR in the pathogenesis of A. hydrophila J-1.

Selection of immunodominant mimics of IROMP-99 of rabbit Pasteurella multocida from a random 12-peptide library

A random 12-peptide library was used to screen immunodominant mimics of 99kDa iron-regulated outer membrane protein (IROMP-99) of rabbit Pasteurella multocida. In the present study, expression of IROMPs of rabbit P. multocida strain C51-12 were analyzed by SDS-PAGE, and Western blot to determine the specificity of rat antiserum antibodies against IROMP-99. Only IROMP-99 whose expression was induced under iron-restricted conditions was detected on nitrocellulose paper. The phage display library was screened with rat normal and IROMP-99-specific antiserum. The positive phage clones were identified using enzyme-linked immunoadsorbent assay (ELISA) and inhibition assays for their reactivity to the antiserum. Out of the 18 randomly selected positive clones that showed higher reactivity to rat antiserum, only ten clones efficaciously inhibited binding of rat antisera to IROMPs and their displayed peptides were determined. Alignment using DNAStar-MegAlign software, results showed that motif WHxTxP was highly conserved among nine clones, only clone A7 had no obvious linear homology with either. Our findings suggest that the motif WHxTxP could be an immunodominant mimic epitope of IROMP-99 of rabbit P. multocida strain C51-12.

Genetic characterization of novel reassortant H1N2 influenza A viruses isolated from pigs in southeastern China

In December 2004, three influenza H1N2 viruses were isolated from lung samples of pigs that had died from respiratory disease on a farm in southeastern China. To determine the genetic characterization and probable origin, one of the three isolates, A/Swine/Zhejiang/1/2004 (Sw/ZJ/1/2004), was genetically analyzed. Sw/ZJ/1/2004 was a reassortant with an NA gene most closely related to the corresponding gene from a human-like H3N2 virus circulating in 1995. The remaining seven genes were most closely related to those from the classical swine H1N1 virus. Sw/ZJ/1/2004 appeared to be a novel reassortant H1N2 virus that was genetically distinguishable from other H1N2 viruses found in pigs worldwide. The isolation of Sw/ZJ/1/2004 provided further evidence for pigs serving as a “mixing vessel” for the generation of new reassortant genotypes of influenza viruses and emphasizes the importance of reinforcing influenza virus surveillance in pigs in China.

Purification and characterization of alpha2-macroglobulin from grass carp Ctenopharyngodon idellus: cloning a segment of the corresponding gene

The plasma protein alpha2-macroglobulin (alpha2M) was purified by gel filtration and anion-exchange chromatography from grass carp plasma. The alpha2M consists of two different subunits of molecular weight 95 kDa and 80 kDa, respectively. The characteristics of grass carp alpha2M are similar to mammalian alpha2M, in that grass carp alpha2M exists in two forms: a fast-form and a slow-form. The former is complexed with protease. The sequence of grass carp alpha2M-conserved region and a region containing the bait region was determined by sequence analysis using polymerase chain reaction (PCR). The deduced amino acid sequence of the conserved region is similar to the alpha2M sequence of common carp, however, the bait region amino acid sequence is dramatically distinct from that of common carp. This may partially explain the differential ability of alpha2M of different species to inhibit different proteases. The alpha2M was able to inhibit Aeromonas hydrophila extracellular protease (AhECPase) and thus may play a role in resistance to infection by this pathogen.

Role of Microfilaments and Microtubules in the Invasion of EPC Cells by Aeromonas hydrophila

The influence of the cytoskeleton on the invasion of Aeromonas hydrophila strain AhJ-1, isolated from diseased fish, in the monolayer cell of epithelioma papillosum cells of carp (EPC) was evaluated by the recovery of gentamicin-resistant bacteria from Triton X-100 cell lysates. The depolymerization of microfilaments (MF) by cytochalasin B and D inhibited the uptake of A. hydrophila in a dose-dependent manner and that of microtubules (MT) by colchicines and nocodazole did not affect the invasion of A. hydrophila in EPC cells significantly. The invasion frequency decreased approximately 62% with the addition of 0.1 microg/ml cytochalasin D and nearly 86% by the addition of 5.0 microg/ml. Invasion decreased approximately 49% and 83% by addition of cytochalasin B in a concentration of 2.5 microg/ml and 10.0 microg/ml. Colchicine and nocodazole, inhibitors of MT formation appears to have little effect on the invasion of EPC cells by strain Ah J-1. Thus MF formation, but not MT formation seems to play an important role in the internalization of A. hydrophila J-1.

Characterization of Streptococcus suis serotype 7 isolates from diseased pigs in Denmark

Isolates of Streptococcus suis serotype 7 from diseased pigs in Denmark were characterized by ribotyping, pulsed field gel electrophoresis (PFGE), MIC-determinations and detection of resistance genes. Forty-one different ribotype profiles were found among the 103 isolates and could be divided into two main clusters. No obvious relationship between ribotypes and the clinical origin of the isolates could be observed. Fifty-four isolates, including all 24 isolates belonging to the main ribotype profile were examined by PFGE and 50 different profiles were found. A high frequency of resistance to erythromycin (41%), tetracycline (24%) and streptomycin (28%) was observed. Furthermore, almost all isolates (101) were resistant to sulphamethoxazol. Most isolates were susceptible to ceftiofur, chloramphenicol, florfenicol, penicillin, ciprofloxacin, trimethoprim and trimethoprim + sulphonamides. The tet(M) gene was found among 11 (44%) and the tet(O) gene in six (24%) of 25 tetracycline resistant isolates. The tet(L) and tet(S) genes were not detected in any isolates. The erm(B) gene was detected in 39 (93%) of 42 erythromycin resistant isolates.

Role of Ichthyophthirius multifiliis in the Infection of Aeromonas hydrophila

Aeromonas hydrophila and Ichthyophthirius multifiliis are important fish pathogens. To clarify their relationship, two host models, goldfish with trauma and those infected with I. multifiliis, were used to study infection kinetics of A. hydrophila 4332 tagged with plasmid pGFPuv (Ah4332(GFP)). The results showed that in fish suffering from ichthyophthiriosis, the bacterial infection process was accelerated and more persistent than in the other groups. It is suggested that I. multifiliis plays an important role in the infection of A. hydrophila. Mechanical trauma caused by I. multifiliis might act as a portal of entry for A. hydrophila present in the water, thereby facilitating the invasion of bacteria. The ectoparasite might also serve as a vector and reservoir of pathogenic bacteria.

[Primary analysis and sequencing the hemolytic relative gene of Edwardsiella tarda]

Hemolysin is an important pathogenic agent of Edwardsiella tarda (ET). A fragment containing hemolytic gene, of which sequence is 4,264 bp, was cloned from ET-12 chromosome by shutgun method. It has no similarity to the hemolysin genes reported, of which 424 bp of open read frame (ORF) 3 has 68% similarity to the hemolysin regulatory gene of S. typhi (slyA). The subclone which has complete ORF3 was hemolytic, and the other of which Kanamycin gene was inserted in Pvu I of ORF3 was no hemolytic. It proved the gene was in chromosomes of ET-12 and the other ET strains by hybridization in situ and Southern blot. As recombination plasmid with the gene entered nonhemolytic ET by electroporation, no hemolytic phenomenon was observed. Conclusion was that the gene wasn't the hemolysin gene and was hemolytic relative gene.

The distribution of monogenean parasites on aquatic vertebrates inhabiting Chinese inland waters

The general distribution of monogenean parasites of aquatic vertebrates inhabiting Chinese inland waters is summarised. Five hundred and seventy-two out of a total of 581 species of monogeneans were discovered on fish, while only nine species were found on Amphibia and Reptilia. Most dactylogyrids and diplozoids parasitise cyprinids, while ancyrocephalids occur on silurids and cyprinids, and gyrodactylids are found mainly on cyprinids and cobitids. Analyses of host-specificity and host-diversity suggests that the family Ancyrocephalidae should be divided into several families parallel with the Dactylogyridae. Of 12 subfamilies of the Cyprinidae, only the Gobiobotinae was found to be free of infection with monogeneans, and the genus Dactylogyrus has more species than any other monogenean genus associated with every cyprinid subfamily.

Antibody against Testudo herpesvirus is not common in Chinese soft-shelled turtles

Seventy-six serum samples of Chinese soft-shelled turtles (Trionyx sinensis) were collected at Jiangsu Province, China. The neutralization test (NT) was performed with the sera, Testudo herpesvirus (THV) and turtle heart cells (THC). Neutralizing antibodies were detected in five of 76 samples and the titres were 1:10-1:20. Having optimized the conditions, the dot-enzyme-linked immunosorbent assay (Dot-ELISA) was developed and eight serum samples exhibited positive results. Five samples were positive by both NT and Dot-ELISA. The percentage of positive samples was only 6.6% (NT) and 11% (ELISA). It is suggested that THV infection is not a serious problem for the Chinese soft-shelled turtle culture in this region.

Structure-reactivity relationships for the inhibition mechanism at the second alkyl-chain-binding site of cholesterol esterase and lipase

Alkyl-N-phenyl carbamates (2-8) (see Figure 1), alkyl-N-phenyl thiocarbamates (9-15), 2,2'-biphenyl-2-ol-2'-N-substituted carbamates (16-23), and 2, 2'-biphenyl-2-N-octadecylcarbamate-2'-N-substituted carbamates (24-31) are prepared and evaluated for their inhibition effects on porcine pancreatic cholesterol esterase and Pseudomona species lipase. All inhibitors are characterized as transient or pseudo substrate inhibitors for both enzymes. Both enzymes are not protected from inhibition and further inactivated by carbamates 2-8 and thiocarbamates 9-15 in the presence of trifluoroacetophenone. Therefore, carbamates 2-8 and thiocarbamates 9-15 are exceptions for active site binding inhibitors and are probably the second alkyl-chain binding-site-directed inhibitors for both enzymes. The inhibition data for carbamates 2-8 and thiocarbamates 9-15 are correlated with the steric constant, E(s), and the hydrophobicity constant, pi; however, the inhibition data are not correlated with the Taft substituent constant, sigma. A comparison of the inhibition data for carbamates 2-8 and thiocarbamates 9-15 toward both enzymes indicates that thiocarbamates 9-15 are more potent inhibitors than carbamates 2-8. A comparison of the inhibition data for cholesterol esterase and Pseudomona species lipase by carbamates 2-8 or thiocarbamates 9-15 indicates that cholesterol esterase is more sensitive to the E(s) and pi values than Pseudomona species lipase. The negative slope values for the logarithms of inhibition data for Pseudomona species lipase by carbamates 2-8 and thiocarbamates 9-15 versus E(s) and pi indicate that the second alkyl-chain-binding site of Pseudomona species lipase is huge, hydrophilic, compared to that of cholesterol esterase, and prefers to interact with a bulky, hydrophilic inhibitor rather than a small, hydrophobic one. On the contrary, the second alkyl-chain-binding site of cholesterol esterase prefers to bind to a small, hydrophobic inhibitor. Both enzymes are protected from inhibition by carbamates 16-23 in the presence of trifluoroacetophenone. Therefore, carbamates 16-23 are characterized as the alkyl chain binding site, esteratic site oxyanion active site directed pseudo substrate inhibitors for both enzymes. Both enzyme inhibition data for carbamates 16-22 are well-correlated with sigma alone. The negative rho values for these correlations indicate that the serine residue of both enzymes and carbamates 16-22 forms the tetrahedral species with more positive charges than inhibitors and the enzymes and follow the formation of the carbamyl enzymes with more positive charges than the tetrahedral species. Carbamates 24-31 are also exceptions for active site binding inhibitors and probably the second alkyl chain binding site-directed inhibitors for both enzymes. However, the enzyme inhibition constants for carbamates 24-31 are correlated with values of sigma, E(s), and pi. The negative rho values for these correlations indicate that both enzymes and carbamates 24-31 form the tetrahedral species with more positive charges than inhibitors and the enzymes and follow the formation of the carbamyl enzymes with more positive charges than those tetrahedral species. Therefore, carbamates 24-31 may bind to both the active sites and the second alkyl chain binding site and follow the evacuation of the active sites. A comparison of the rho values for cholesterol esterase and Pseudomona species lipase by carbamates 24-31 indicates that cholesterol esterase is much more sensitive to the sigma values than Pseudomona species lipase. The negative sensitivity values, delta, for the cholesterol esterase inhibitions by carbamates 24-31 indicate that the enzyme prefers to bind to a bulky carbamyl group rather than bind to a small one. The hydrophobicity of carbamates 24-31 does not play a major role in both enzyme inhibitions.

Structure-reactivity probes for active site shapes of cholesterol esterase by carbamate inhibitors

4,4'-Biphenyl-di-N-butylcarbamate (1), (S)-1,1'-bi-2-naphthyl-2, 2'-di-N-butylcarbamate (S-2), (S)-1, 1'-bi-2-naphthyl-2-N-butylcarbamate-2'-butyrate (S-3), 2, 2'-biphenyl-di-N-butylcarbamate (4), 2, 2'-biphenyl-2-N-octadecylcarbamate-2'-N-octylcarbamate (5), 2, 2'-biphenyl-2-N-octadecylcarbamate-2'-N-phenylcarbamate (6), 2, 2'-biphenyl-2-N-butylcarbamate-2'-butyrate (7), 2, 2'-biphenyl-2-N-butylcarbamate-2'-ol (8), 2, 2'-biphenyl-2-N-octylcarbamate-2'-ol (9), (R)-1, 1'-bi-2-N-naphthyl-2-butylcarbamate-2'-ol (R-10), and glyceryl-1,2, 3-tri-N-butylcarbamate (11) are prepared and evaluated for their inhibition effects on porcine pancreatic cholesterol esterase. All inhibitors are irreversible inhibitors of the enzyme. Carbamates 1-3 and 7-10 are the first alkyl chain and esteratic binding site-directed irreversible inhibitors due to the fact that the reactivity of the enzyme is protected by the irreversible inhibitor, trifluoroacetophenone in the presence of these carbamates. Carbamate 1 is the least potent inhibitor for the enzyme probably due to the fact that the inhibitor molecule adopts a linear conformation and one of the carbamyl groups of the inhibitor molecule covalently interacts with the first alkyl chain binding site of the enzyme while the other carbamyl group of the inhibitor molecule exposes outside the active site. With near orthogonal conformations at the pivot bond of biaryl groups, one carbamyl group of carbamates S-2, S-3, and R-10 covalently binds to the first alkyl chain binding site of the enzyme while the other carbamyl, butyryl, or hydroxy group can not bind covalently to the second alkyl chain binding site probably due to the orthogonal conformations. Carbamates 4-9 and 11 are very potent inhibitors for the enzyme probably due to the fact that all these molecules freely rotate at the pivot bond of the biphenyl or glyceryl group and therefore can fit well into the bent-shaped first and second alkyl chains binding sites of the enzyme. Although, carbamates 4-6 and 11 are irreversible inhibitors of cholesterol esterase, the enzyme is not protected but further inhibited by trifluoroacetophenone in the presence of these carbamates. Therefore, carbamates 4-6 and 11 covalently bind to the first alkyl chain binding site of the enzyme by one of the carbamyl groups and may also bind to the second alkyl chain binding site of the enzyme by the second carbamyl group. Besides the bent-shaped conformation, the inhibition by carbamate 6 is probably assisted by a favorable pi-pi interaction between Phe 324 at the second alkyl chain binding site of the enzyme and the phenyl group of the inhibitor molecule. For cholesterol esterase, carbamates 8-10 are more potent than carbamates S-2, 4, and 5 probably due to the fact that the inhibitor molecules interact with the second alkyl chain binding site of the enzyme through a hydrogen bond between the phenol hydroxy group of the inhibitor molecules and the His 435 residue in that site.

Electron microscopic observation on a non-occluded baculo-like virus in shrimps

A severe disease of farm-raised shrimp, Penaeus chinensis has spread throughout Chinese coasts since 1993. Recently, a baculo-like virus has been diagnosed as the causative agent for this epidemic disease. The electron microscopic observation of the virus is described. Thin sections of hepatopancreatic and hypodermic tissue of diseased P. chinensis showed many rod-shaped, enveloped, baculo-like virions in hypertrophied nuclei of infected cells. The virion was filled with a highly electron dense core. No occlusion bodies have been found. Negative stained intact virions, purified from infected tissues by centrifugation on sucrose discontinuous gradients, demonstrated that the viral envelops had been broken, but the cylindrical nucleocapside could be observed clearly. The nucleocapsid of average 62 nm x 314 nm was composed of a helix system of capsomers, giving rise to an open stacked ring structure and repeating approximately every third ring. The number of repeating unit was 13 to 15. We propose that the virus described here could be designated as Non-Occluded Shrimp Virus (NOSV) or Penaeus chinensis Baculo-Like Virus (PcBLV).

Serial changes in ultrasound-guided fine needle aspiration cytology in subacute thyroiditis

OBJECTIVE

To elucidate the serial cytologic presentations of subacute thyroiditis (SAT) with ultrasound-guided fine needle aspiration (FNA).

STUDY DESIGN

Nine patients with clinically evident SAT were recruited; serial sonography and ultrasound-guided fine needle aspiration cytology were performed.

RESULTS

Sixty-one follow-up examinations were obtained in nine patients. The follow-up ranged from 1 to 5 months (mean, 3.3). Initial sonographic presentations revealed focal hypoechogenicity in three patients and multiple hypoechogenicity in six. Initial cytologic findings showed chiefly enlarged, degenerated follicular cells with prominent nucleoli, lymphocytes, colloid substance, multinucleated giant cells and neutrophils. Regression of sonographic hypoechogenicity paralleled the disappearance of acute inflammatory cells and enlarged, degenerated follicular cells and the appearance of cohesive follicles.

CONCLUSION

Improvement of SAT in sonography is fairly parallel to that in cytology even though there is a lag of improvement in the latter. Smear pattern is also related to the clinical stage of SAT. Ultrasound-guided FNA is a convenient method of obtaining sufficient and representative specimens in patients with SAT.

Therapeutic responses to corticosteroids in Graves' ophthalmopathy

To elucidate the therapeutic responses to corticosteroids and prognostic factors in the treatment of Graves' ophthalmopathy, 23 patients with Graves' ophthalmopathy were treated with intravenous methylprednisolone 0.5 g daily for 3 days, followed by prednisolone 40 mg daily. Dosage was reduced gradually to 10 mg daily over 4 weeks. The symptoms and signs of the eyes were recorded. Orbital computed tomography and urinary glycosaminoglycan excretion testing were performed before treatment. We observed the effectiveness of treatment at 6 months as the endpoint of this study and classified the response as good or poor. We compared the differences in parameters between these two groups. The results showed that 12 (52%) out of 23 patients had a good response, and three (25%) of those with a good response recovered completely. Corticosteroid therapy dramatically improved lacrimation, reduced soreness and congestion of the eyes and ameliorated exophthalmos, lagophthalmos and extraocular muscle movement. Four (36%) of the 11 patients with a poor response had rebound of symptoms and/or signs after the dosage of prednisolone was decreased. Those with a good response were usually younger, and enlargement of the extraocular muscle was also milder than in those with a poor response. This study demonstrated that corticosteroid therapy is effective in Graves' ophthalmopathy and that extraocular muscle size demonstrated by orbital computed tomography is a prognostic factor of therapy.

[A randomized clinical trial for the evaluation of head and neck squamous cell carcinoma treating with traditional Chinese medicine]

This paper described the research design,research process and statistical analysis of randomized clinical trial by treatment with traditional Chinese medicine in patients with squamous cell carcinoma of the head and neck.At first we found there was no significant difference between treating group and contral group(P>0.05) using log-rank test on Kaplan-Meier survival curves. With further multivariate analysis Cox model and after adjusting for sex,age,legth of taking the assigned medication,grade of tumor differentiation and using of chemotherapy,the rate of tumor-related death for control group was significantly higher than that for treating group :hazards ratio estimate was 1.939(95% confidence interval 1.008-3.729,(P<0.05).The length of taking Chinese medicine was one of the most important prognostic factors(P<0.001).The results suggest that the prescribed medication contributed to the improved survival,and it was an independent prognostic factor.

Self-organization of an oscillatory neural system

Hebbian dynamics is used to derive the differential equations for the synaptic strengths in the neural circuitry of the locomotive oscillator. Initially, neural connection are random. Under a specified arborization hypothesis relating to the density of neural connections, the differential equations are shown to model the self-organization and the stability of the oscillator.

Prevalence of goiter in school children in the Wan-Hwa district of Taipei

Salt has been iodized in Taiwan since 1967. To understand goiter status after salt iodization, we studied the prevalence of goiter in school children in rural areas where tap water or underground water are used. To further elucidate the prevalence of goiter in urban areas where tap water is used, we studied school children from the Tong-Yuan and Lao-Song elementary schools located in the Wan-Hwa District of Taipei. Thyroid enlargement was examined by palpation as recommended by the World Health Organization. Thyroid antibodies and hormones were determined in school children with goiter and in age- and sex-matched normal control children using particle agglutination methods and radioimmunoassay. A total of 4,623 school children were examined. Of these, 129 children (2.8%) had goiters of grade I or above, or nodular goiters. The prevalence of goiter was similar to that of Putai and Peimen in southern Taiwan where tap water is used, but less than that of Tachia and Chingshuei in middle Taiwan where underground water is used. The prevalence of goiter was much lower than recent studies in Tung-Lo, an oil-bearing area in middle Taiwan, where there was a 12.9% prevalence in school children residing in hill districts who relied on underground water for drinking purposes, and 8.2% in school children residing on lower plains, who depended upon tap water for drinking purposes. The prevalence of goiter is highly related to the quality of drinking water.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk factors of coronary arterial aneurysm in Kawasaki disease

From April 1983 to August 1991, 70 cases of Kawasaki disease were admitted to Taiwan Provincial Tao-Yuan General Hospital. Fifty-seven patients treated with aspirin 80-100 mg/kg/day alone during the acute phase were followed by two-dimensional echocardiography for two weeks to two years. Twelve cases (21%) complicated with coronary arterial aneurysm (CAA) were referred as high risk group. Those who had no CAA were a low risk group. Stepwise discriminant analysis was performed to obtain risk factors of CAA based on clinical and early laboratory data. This yielded a classification accuracy of 75.4%. The combination of two parameters, white blood cell count and C-reactive protein, can be applied to early identify Kawasaki patients at high or low risk of CAA.

Neural organization of the locomotive oscillator

We study the relation of neural development, organization, and activity to behavior. We provide a model of the locomotive oscillator, a neural system supplying alternating stimulation to extensor and flexor muscles creating an oscillatory motion. We propose a protocol by which this neural system starting from unstructured, unconnected neural populations develops structure and function. The protocol is studied by both computer simulation and mathematical analysis. Our main results are 1. The locomotive oscillator self-organizes and maintains its organization, assuming certain properties of the neural populations. 2. Imperfections disturbing the functional adequacy of the neural populations may lead to the deterioration and disappearance of the oscillatory behavior. 3. The locomotive oscillator may fail to organize if the development is not staged in time.

Intestinal malrotation and gastric perforation in a newborn with tetralogy of Fallot: report of one case

Gastric perforation with gastrointestinal anomaly is rare in newborns. A case of Tetralogy of Fallot with both malrotation and gastric perforation is reported. Before operation, malrotation was diagnosed from the x-ray films. Laparotomy disclosed a linear perforation on the posterior wall of the gastric body. Mechanical obstruction might have played a role in this case.

The neonatal morbidity and mortality of low birth weight neonates

During the period between January 1, 1987 and March 31, 1991, a total of 454 low birth weight neonates, classified if below 2,500 grams, admitted to this hospital, 450 of them could be evaluated retrospectively. Among the 450 cases, 41 (9.1%) were transferred from outside hospitals within 24 hours of birth; and 409 were original hospital inpatients. The sex distribution was quite even (M/F = 227/223), but more than half of them were small-for-date (56.4%). Multiple pregnancy accounted for 22.9%, and toxemic mother, for 11.6%. Neonatal mortality rates were 23.9% for those with birth weight below 1,500, and 45.5% for those with birth weight below 1,000 grams, respectively. Respiratory distress syndrome occurred in 15.9% of the low birth weight neonates, and the incidence increased stepwise as birth weight decreased. Symptomatic patent ductus arteriosus could be detected in 11%. Fundoscopical evaluation, a routine for all with birth weight below 1,500 grams or below 2,000 grams with prolonged ventilator support, demonstrated retinopathy of prematurity in 5.6% of all cases or 50% in those below 1,000 grams. Routine brain echo done in all those below 2,000 grams within the first three days of age, and at least once every week thereafter, revealed intracranial hemorrhage in 10.2%, but only 2.4% belonged to grade III-IV. Respiratory distress syndrome and outborn were the two major determinants affecting the severity and occurrence of intraventricular hemorrhage significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronavirus as an agent of neonatal calf diarrhea in a Chinese dairy cattle farm

Neonatal calf diarrhea is a significant health problem in dairy industry in the whole world. Although the aetiological agents of neonatal diarrhea are diverse, it is obvious that viruses play an important role. One of them is bovine coronavirus (BCV). Since BCV was discovered (MEBUS et al., 1969), there have been many published reports describing the virus and its importance in calves. In China, we first investigated the seroepidemiological status of BCV infections in cattle (YAO et al., 1990). The results showed that the incidence of infections with BCV in cattle in different chinese regions are high. Further work on direct diagnosis of BCV as a causative agent of diarrhea was therefore necessary. In the last years we have developed diagnostic methods including a monoclonal antibody-based ELISA to detect BCV and other diarrheal viruses. In this study, the diagnosis of an outbreak of BCV in chinese dairy cattle is described.

[In vivo metastasis of human tumor transplant in T and NK cell immune-deficient mice]

Beige-nude mice with combined T and NK cell deficiency were produced by introducing "nu" gene into the beige mice of C57BL/6 background. The beige-nude mice were characterized by morphological features, level and activity of the NK cell in spleen and peripheral blood. NK cell level of the beige-nude mice was higher than the beige mice and similar to the ordinary nude mice though its NK cell activity was markedly lower than the nude mice. Human lung adenocarcinoma (PAa) was transplanted subcutaneously to the beige-nude mice and nude mice of BALB/cA background. No metastasis was found in BALB/cA nude mice (0/7), while in beige-nude mice, spontaneous lymph node metastasis rate was 36.3% (4/11). It should be noted that the transplanted PAa metastasized to lungs, which had never been seen in BALB/cA nude mice in previous experiments. The increase of metastatic rate is correlated with the relative low NK cell activity of the beige-nude mice. Our observation is that the beige-nude mice could be a suitable experimental model for in vivo study on metastatic behavior of the human tumors.