[Relationship between blood glucose variation, collateral circulation and Batman score and prognosis after mechanical thrombectomy with Solitaire stent in acute posterior vascular occlusive stroke]

Objective: To explore the relationship between blood glucose variability, collateral circulation and basilar artery computed scan angiography score (Batman) and prognosis of mechanical thrombectomy with Solitaire stent in patients with large vascular occlusive APCI. Methods: A retrospective study was conducted on 113 patients with large vessel occlusive APCI who underwent Solitaire stent mechanical thrombectomy in the Department of Neurology of Nanyang Central Hospital from March 2021 to July 2022. According to the prognosis, they were divided into outcome group (46 cases) and adverse group (67 cases). Evaluate the prognosis based on the Modified Rankin Scale three months after the surgery. The differences in collateral circulation, GV and Batman score between the two groups were compared, and the related factors affecting the prognosis of large vessel occlusive APCI patients treated with Solitaire stent mechanical thrombectomy were analyzed by multivariate logistic regression model. Results: The age of 113 patients with acute large vessel occlusive APCI was (65.3±8.9) years old. The proportion of female was 34.5% (39 cases). Compared with the outcome group, the adverse group had a lower proportion of collateral circulation [40 cases (87.0%) vs 47 cases (70.2%)], higher GV score [(25.19±3.54) vs (30.36±4.11) points], lower Batman score [(7.49±1.52) vs (6.65±1.33) points], higher proportion of atrial fibrillation history [16 cases (23.9%) vs 4 cases (8.7%)], higher National Institutes of Health Stroke Scale (NIHSS) score at admission [(8.33±0.74) vs (7.25±0.92) points], larger core infarct volume [(32.57±4.87) vs (29.54±5.14) ml], and longer time from admission to vascular recanalization [(123.52±31.17) vs (102.47±29.54) min] (all P<0.05). Atrial fibrillation history, core infarct volume, NIHSS score at admission, time from admission to vascular recanalization, glycemic variability, collateral circulation, and Batman score were related factors for the prognosis of large vessel occlusive APCI patients treated with Solitaire stent mechanical thrombectomy, with ORvalues (95%CI) of 1.383 (1.124-1.641), 1.166 (1.007-1.350), 4.777 (1.856-12.297), 3.068 (2.379-3.757), 1.477 (1.209-1.806), 0.742 (0.654-0.831), and 0.717 (0.214-1.221), respectively (all P<0.05). Conclusion: Blood glucose variation is a risk factor for prognosis of mechanical thrombectomy with Solitaire stent in patients with large vascular occlusive APCI, and collateral circulation and Batman score are protective factors.

[Study on primary screening technique for children with autism spectrum disorder]

To explore screening tools for children with autism spectrum disorder (ASD), which are convenient for primary hospitals, it can provide basic data for formulating ASD prevention policies. This was a cross-sectional study by cluster sampling. Huyi District and Xincheng District were extracted for investigation in Xi'an City. From July 2021 to September 2022, all children aged from 3 months to 36 months who live in the two districts were subjected to primary screening. The child care physician used the routine screening tool "warning signs checklist for screening psychological, behavioral and developmental problems of children" and cartoon pictures of "early high-risk warning signs of autism", the children who were positive in the initial screening were referred to the district level maternal and child health hospital for re-screening, and those who were positive in the re-screening were referred to Xi 'an Children's Hospital for diagnosis. The results showed that a total of 17 905 children aged from 3 months to 36 months were initially screened in the two districts, including 10 588 children aged from 18 months to 36 months, 50 children who were positive in the initial screening and 50 children who were re-screened. 23 children (18 boys and 5 girls) were diagnosed with ASD. The prevalence rate of ASD in children was 2.17‰ (95% confidence interval:1.29‰-3.06‰). 42 children were positive for "warning signs checklist" at the preliminary screening, and 19 were confirmed as ASD. 27 children were positive for "cartoon pictures" in the preliminary screening, and 23 were confirmed with ASD. The "cartoon pictures" in the preliminary screening and diagnosis of consistent rate was higher than the "warning signs checklist", two kinds of screening methods comparison were statistically significant difference in the odds of consistent (χ2=11.01, P=0.001). In conclusion, relying on the three-level network of maternal and child health care, it is conducive to the whole process management of screening and diagnosis of children with ASD, and to guide the formulation of prevention policies. The cartoon pictures of "early high-risk warning signs of autism" can assist the identification of children with ASD based on the "warning signs checklist", which is simple, effective and suitable for promotion in the community health care.

Expression, signal transduction, and function analysis of TIRAP and TRIF in Nile tilapia (Oreochromis niloticus)

Toll/interleukin 1 receptor domain-containing adaptor protein (TIRAP) and toll/interleukin 1 receptor-domain-containing adapter-inducing interferon-β (TRIF) are crucial adaptors of signal transduction for the signaling pathways of toll-like receptors (TLRs). TIRAP and TRIF perform an essential function in an antimicrobial immune response; however, their function in Nile tilapia remains unknown. Herein, TIRAP and TRIF from Nile tilapia were identified and functionally characterized. Phylogenetic analysis showed that OnTIRAP and OnTRIF clustered with corresponding homologs from other fish species, with comparable gene structures to those of select vertebrate TIRAP and TRIF genes, respectively. The expression profiles of OnTIRAP and OnTRIF were broadly distributed in the ten tissues investigated, with high transcript levels noticed in immune organs. The transcription levels of OnTIRAP and OnTRIF were upregulated in response to bacterial and poly (I:C) challenges. GFP signals were only detected in the cytoplasmic region of fish cells transfected with OnTIRAP-GFP and OnTRIF-GFP expression plasmids. Moreover, overexpression of OnTIRAP and OnTRIF activated interferon-β (IFN-β) and activator protein 1 (AP1) reporters in HEK 293 cells. Activation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) reporter was only observed in OnTRIF-overexpressing HEK 293 cells. Furthermore, the results of the co-immunoprecipitation analysis showed that OnTRIF, but not OnTIRAP, was recruited as an adaptor protein by OnTLR25. This study provides the first evidence on the functions of OnTIRAP and OnTRIF in the immune system of Nile tilapia against pathogens and may serve as the basis for further investigations on TLR signaling in fish.

Immunostimulatory effects of Sarcodia suiae water extracts on Nile tilapia Oreochromis niloticus and its resistance against Streptococcus agalactiae

In this study, water extracts of the red seaweed Sarcodia suiae were obtained using solid-liquid extraction (SLE) or pressurized liquid extraction (PLE) methods. The extracts were used to investigate immunostimulatory activity by measuring the phagocytic activity of Nile tilapia (Oreochromis niloticus) hepatic and splenic macrophages and the tilapia head kidney (THK) cell line, and modulation of immune-related genes in primary head kidney (HK) cells and THK cells. At 10 μg/ml, both extracts promoted the proliferation of hepatic and splenic macrophages. Expression levels of proinflammatory cytokines (IL-1β and IL-8), antimicrobial peptides (TP2 and TP4), and pattern recognition receptors (TLR5) were elevated in SLE extracts-treated primary HK leukocytes. Similarly, IL-1β, IL-8, and TNFα expression was also induced by SLE extract in THK cells. Phagocytic activity in primary HK cells and THK cells was induced by SLE extract 12 h and 24 h post-stimulation, while PLE extract only induced phagocytic activity in THK cells at early time points. SLE extract (100 μg/g body weight) increased the expression of IL-1β, IL-8, TNFα, TP2, TP4, TLR2 and TLR5 in the spleen and immunoprotective efficiency against Streptococcus agalactiae infection. Taken together, these results show that S. suiae can differentially stimulate the immune response of tilapia in vitro and in vivo and could potentially be used as an immunomodulator in tilapia culture.

Complete genome sequence and phylogenetic analysis of a novel aquareovirus isolated from a diseased marbled eel (Anguilla marmorata)

Marbled eel reovirus (MERV) is an aquareovirus (AQRV) isolated from diseased marbled eels (Anguilla marmorata) with petechial skin hemorrhage. In this study, we propagated MERV in a cell line derived from the brain of Aequidens rivulatus and purified viral particles by using a discontinuous cesium chloride gradient. Genomic RNA sequences were obtained through next-generation sequencing. MERV, similar to most other AQRVs, showed the presence of 11 double-stranded RNA segments encoding 12 proteins; however, the genome sequence displayed very little similarity to known AQRV sequences. Furthermore, the structural proteins of MERV were most closely related to American grass carp reovirus with sequence identity values of no more than 64.89%. Phylogenetic analysis based on the sequences of structural proteins indicated that MERV shows an evolutionary history between AQRV-B and -G, which belong to the saline and freshwater environment subgroups, respectively. We also observed that MERV showed a closer relationship to orthoreoviruses based on the protein sequences of NS38 and NS73. In summary, MERV is a novel AQRV that could be classified as a member of the new proposed AQRV species "Aquareovirus H". The taxonomic assignments and evolution of AQRVs thus warrant further investigation.

[Factors influencing poor prognosis of mechanical thrombectomy in time window of acute ischemic stroke]

Objective: Investigate the causes of poor prognosis of mechanical thrombectomy in the time window of acute ischemic stroke (AIS) with anterior circulation. Methods: A retrospective analysis was made on the data of 78 patients with anterior circulation AIS who underwent mechanical thrombectomy in the time window from January 2017 to December 2017 in the Department of Vascular Neurosurgery of Liaocheng Brain Hospital. The modified Rankin scale (mRS) was used to evaluate the prognosis of the patients 3 months after operation. According to the prognosis,the patients were divided into the group with good prognosis (42 cases, mRS<2 points) and the group with poor prognosis (36 cases, mRS<3 points). Univariate and multivariate Logistic regression analysis was used to analyze the related factors of poor prognosis. Results: (1) Univariate analysis showed that the prognosis of patients with good combination and primary stenosis of diabetes mellitus and atherosclerosis was lower than that of patients with poor prognosis (P<0.05). The collateral circulation compensation rate and vascular recanalization rate of patients with good prognosis were higher than those of patients with poor prognosis (P<0.05). Learning significance (P<0.05). (2) Multivariate analysis showed that diabetes mellitus (P=0.035), collateral circulation compensation (P=0.011) and primary atherosclerotic stenosis (P=0.042) were independent risk factors for poor prognosis. Conclusion: Perfect preoperative evaluation and strict screening of patients, good collateral circulation compensation,individualized treatment for patients with primary atherosclerotic stenosis,and strict control of postoperative hyperglycemia can improve the clinical prognosis of endovascular therapy.

Development, characterization and virus susceptibility of a continuous cell line from the caudal fin of marbled eel (Anguilla marmorata)

A continuous cell line consisting mostly of epithelioid cells was established from the caudal fin of marbled eels (Anguilla marmorata) and designated as marbled eel caudal fin (MECF)-1. The cells multiplied well in Leibovitz's L-15 medium containing 2% to 15% foetal bovine serum at temperatures of 20°C to 35°C and were subcultured for >90 passages during a 5-year period from 2012 to 2017. Transcripts of ictacalcin, keratin 13, cd146, nestin, ncam1 and myod1 were demonstrated in the cells using reverse transcription polymerase chain reaction. The results indicated that MECF-1 was composed of epidermal and mesenchyme stem and progenitor cells including myoblasts. MECF-1 was susceptible to Japanese eel herpesvirus HVA980811, marbled eel polyoma-like virus (MEPyV), aquabirnavirus MEIPNV1310 and aquareovirus CSV. By contrast, MECF-1 was noted refractory to megalocytiviruses RSIV-Ku and GSIV-K1 infection. Moreover, the cells were resistant to betanodavirus infection. In conclusion, MECF-1 derived from marbled eel is suitable for studies on anguillid viruses and interaction with host cells.

Characterization and virus susceptibility of a continuous cell line derived from the brain of Aequidens rivulatus (Günther)

Cell cultures derived from the brain tissues of Aequidens rivulatus (Günther) have been characterized previously. In this study, a continuous cell line ARB8 was further established, and its growth characteristics, transcription and susceptibility to fish viruses-including chum salmon reovirus (CSV), marbled eel infectious pancreative necrosis virus (MEIPNV), grouper nervous necrosis virus (GNNV), giant seaperch iridovirus (GSIV), red seabream iridovirus (RSIV), koi herpesvirus (KHV), herpesvirus anguilla (HVA) and marbled eel polyoma-like virus (MEPyV)-were examined. ARB8 cells that showed epithelioid morphology and were passaged >80 times grew well at temperatures ranging from 25°C to 30°C in L-15 medium containing 5%-15% foetal bovine serum. The cells constitutively transcribed connexion 43, glutamine synthetase, nestin and nkx6-2, which are markers for neural progenitor cells. The cells were highly susceptible to CSV, MEIPNV, GSIV and RSIV and showed the typical cytopathic effect (CPE). However, the cells were resistant to GNNV, KHV, HVA and MEPyV because no significant CPE was noted after infection. Optimal temperatures for virus production ranged from 25°C to 30°C. The results revealed that the neural progenitor cell line ARB8 can potentially serve as a useful tool for investigating fish viruses and isolating new viruses in ornamental cichlid fishes.

Immunocytochemical characterisation of neural stem-progenitor cells from green terror cichlid Aequidens rivulatus

In this study, cultures of neural stem-progenitor cells (NSPC) from the brain of green terror cichlid Aequidens rivulatus were established and various NSPCs were demonstrated using immunocytochemistry. All of the NSPCs expressed brain lipid-binding protein, dopamine- and cAMP-regulated neuronal phosphoprotein 32 (DARPP-32), oligodendrocyte transcription factor 2, paired box 6 and sex determining region Y-box 2. The intensity and localisation of these proteins, however, varied among the different NSPCs. Despite being intermediate cells, NSPCs can be divided into radial glial cells, oligodendrocyte progenitor cells (OPC) and neuroblasts by expressing the astrocyte marker glial fibrillary acidic protein (GFAP), OPC marker A2B5 and neuronal markers, including acetyl-tubulin, βIII-tubulin, microtubule-associated protein 2 and neurofilament protein. Nevertheless, astrocytes were polymorphic and were the most dominant cells in the NSPC cultures. By using Matrigel, radial glia exhibiting a long GFAP⁺ or DARPP-32⁺ fibre and neurons exhibiting a significant acetyl-tubulin⁺ process were obtained. The results confirmed that NSPCs obtained from A. rivulatus brains can proliferate and differentiate into neurons in vitro. Clonal culture can be useful for further studying the distinct NSPCs.

Characterization and viral susceptibility of a brain cell line from brown-marbled grouper Epinephelus fuscoguttatus (Forsskål) with persistent betanodavirus infection

A continuous cell line designated BMGB (brown-marbled grouper brain) was established from the brain tissues of the brown-marbled grouper Epinephelus fuscoguttatus and characterized. BMGB cells were identified as astroglial progenitor cells because they expressed glial fibrillary acidic protein and keratin and were persistently infected by betanodavirus, as confirmed through immunocytochemistry, polymerase chain reaction and immunoblot analyses. Because few intact virions were present in the BMGB cell culture fluid, the cytopathic effect (CPE) was not observed when the culture fluid was inoculated with GBC1 cells. However, BMGB cells displayed typical CPE after infection with additional betanodavirus, megalocytivirus and chum salmon reovirus. BMGB cells showed low myxovirus resistance (Mx) protein expression, which increased following betanodavirus and reovirus infection. Because the cells contained several unusual or degraded viral proteins, the persistent infection of betanodavirus in the BMGB cells may have resulted from a mechanism that destroys the viral proteins rather than the result of Mx protein expression. Despite the persistent betanodavirus infection, BMGB cells proliferated in a manner similar to other normal tropic fish cells and supported the propagation of several piscine viruses; however, the yield was lower than that of normal cells. The BMGB cells will be useful for investigating virus and host cell interaction.

Isolation of a novel polyomavirus, related to Japanese eel endothelial cell-infecting virus, from marbled eels, Anguilla marmorata (Quoy & Gaimard)

Marbled eels, Anguilla marmorata (Quoy & Gaimard), cultured in Taiwan exhibited haemorrhage and mortality in January 2012. The severely diseased eels bled from the gills and showed congestion of the central venous sinus of the gill filaments and haemorrhage throughout the body similar to viral endothelial cell necrosis of eel. In this study, a novel polyomavirus (AmPyV) was isolated from the diseased eels using the AMPF cell line established from the pectoral fin of healthy marbled eels. AmPyV was found to encode a long T-antigen orthologous gene. Phylogenetic analysis showed that AmPyV was closely related to Japanese eel endothelial cell-infecting virus. PCR assays revealed AmPyV infection throughout the systemic organs. AmPyV proliferated in the AMPF, EK-1 and EO-2 cells at temperatures 25-30 °C, and the progeny virus yields were 10(7.0) , 10(7.4) and 10(7.7) TCID50  mL(-1) , respectively. The purified virions were icosahedral particles, 70-80 nm in diameter. No clinical signs or mortality was observed among the eels injected with the virus; however, the virus was reisolated from the brain, eyes, kidneys, fins and gills of infected eels 2 month after injection. Our results suggest that AmPyV exhibits a latent infection. Pathogen of the disease needs to study further.

Development and characterization of a cell line from tilapia head kidney with melanomacrophage characteristics

A novel cell line THK, derived from the tilapia head kidney, was developed and characterized. The THK cell line comprised fibroblastoid cells that markedly proliferated in Leibovitz L-15 medium containing 2%-15% fetal bovine serum (FBS) at 20 °C-35 °C. Cell proliferation was dependent on the FBS concentration, and the optimal temperature for proliferation ranged between 25 °C and 30 °C. THK cells were characterized for the presence of phagocytic activity, acid phosphatase, alkaline phosphatase, α-naphthyl acetate esterase, lipofuscin, and tyrosinase. Transcripts of CD33, CD53, CD82, CD205, macrophage colony stimulating factor receptor, GATA2, and GATA3 that are specific for leucocytes or monocytes/macrophages or both were detected in the THK cells through PCR. However, THK cells lacked for CD83, a specific marker for dendritic cells. The results indicated that the fibroblastoid THK cells were melanomacrophage-related progenitors. PCR revealed that the THK cells exhibited the transcripts of toll-like receptor 1 (TLR1), TLR2, TLR3, and CD200, of which concern with immunity as well as the transcripts of vascular endothelial growth factor receptor 3, angiomotin, and angiopoietin-like protein 2 that associate with angiogenesis regulation and macrophage proliferation. THK cells were subcultured more than 90 times and can be useful for investigating the development and functioning of the teleostean innate immune system.

Giant seaperch iridovirus (GSIV) induces mitochondria-mediated cell death that is suppressed by bongkrekic acid and cycloheximide in a fish cell line

Giant seaperch iridovirus (GSIV) induces cell death by an unknown mechanism. We postulated that this mechanism involves mitochondria-mediated cell death. Cell viability assays revealed a steady increase in dead grouper fin cells (GF-1) after GSIV infection, from 11% at 2 days post-infection (dpi) to 67% at 5 dpi. Annexin V/PI staining revealed GSIV infection induced apoptosis in a steadily increasing fraction of cells, from 4% at 1 dpi to 29% at 5 dpi. Furthermore, post-apoptotic necrosis was apparent at 4 and 5 dpi in the late replication stage. In the early replication stage, JC-1 dye revealed mitochondrial membrane potential (ΔΨm) loss in 42% of infected cells at 1 dpi, increasing to 98% at 3 dpi. Phosphatidylserine (PS) exposure and loss of ΔΨm from apoptosis/necrosis was attenuated by treatment with the adenine nucleotide translocase inhibitor bongkrekic acid (BKA) and the protein synthesis inhibitor cyclohexamide (CHX). These data suggest GSIV induces GF-1 apoptotic/necrotic cell death through pathways that require newly synthesized protein and involve the mitochondrial function.

Giant seaperch iridovirus infection upregulates Bas and Bak expression, leading to apoptotic death of fish cells

The giant seaperch iridovirus (GSIV) induces host cell apoptosis by a poorly-understood process. In this study, GSIV is shown to upregulate the pro-apoptotic death genes Bax and Bak at the middle replication stage, and factors in the grouper fin cell line (GF-1) are shown to modulate this process. Studying the mechanism of cell death, we found that upregulated, de novo-synthesized Bax and Bak proteins formed heterodimers. This up-regulation process correlated with mitochondrial membrane potential (MMP) loss, increased caspase-3 activity, and increased apoptotic cell death. All effects were diminished by treatment of infected GF-1 cells with the protein synthesis inhibitor cycloheximide. Interestingly, overexpression of the anti-apoptotic gene Bcl-xL also diminished GSIV-induced mitochondria-mediated cell death, increasing host cell viability and decreasing MMP loss at the early replication stage. Our data suggest that GSIV induces GF-1 apoptotic cell death through up-regulation of the pro-apoptotic genes Bax and Bak, which are regulated by Bcl-xL overexpression on mitochondria in GF-1 cells.

Immunochemical and molecular characterization of a novel cell line derived from the brain of Trachinotus blochii (Teleostei, Perciformes): A fish cell line with oligodendrocyte progenitor cell and tanycyte characteristics

Ependymal radial glial cells, also called tanycytes, are the predominant glial fibrillary acidic protein (GFAP)- and vimentin (VIM)-expressing cells in fish ependyma. Radial glial cells have been proposed to be neural stem cells but their molecular expression is not well understood. Previous studies revealed that fish neural progenitor and neural stem cells have A2B5, a marker for oligodendrocyte progenitor cells (OPCs). In this study, an A2B5(+) cell line, SPB, was isolated from the brain of the teleost Trachinotus blochii and characterized. SPB cells usually grew as polygonal epithelial cells, but at high density, long processes were commonly observed. Using immunocytochemistry, SPB cells were shown to exhibit oligodendrocyte markers such as galactocerebroside and Olig2, and radial glial cell markers such as brain lipid-binding protein, GFAP, Sox2, and VIM. SPB cells were also observed to have DARPP-32, a marker for tanycytes in mammals, and primary cilia. RT-PCR additionally revealed expression of bone morphogenetic protein 4, connexin35, Noggin2, and proteolipid protein in SPB cells. Results of this study suggest that SPB cells are OPCs that can display tanycyte characteristics. Fish tanycytes can be neural stem cells suggesting that SPB cells are neural stem cells. SPB is the first fish cell line showing primary cilia and markers for both OPCs and tanycytes.

PCR amplification and sequence analysis of the major capsid protein gene of megalocytiviruses isolated in Taiwan

Viruses belonging to the genus Megalocytivirus in the family Iridoviridae are one of the major agents causing mass mortalities in marine and freshwater fish in Asian countries. Outbreaks of iridovirus disease have been reported among various fish species in Taiwan. However, the genotypes of these iridoviruses have not yet been determined. In this study, seven megalocytivirus isolates from four fish species: king grouper, Epinephelus lanceolatus (Bloch), barramundi perch, Lates calcarifer (Bloch), silver sea bream, Rhabdosargus sarba (Forsskal), and common ponyfish, Leiognathus equulus (Forsskal), cultured in three different regions of Taiwan were collected. The full open reading frame encoding the viral major capsid protein gene was amplified using PCR. The PCR products of approximately 1581 bp were cloned and the nucleotide sequences were phylogenetically analysed. Results showed that all seven PCR products contained a unique open reading frame with 1362 nucleotides and encoded a structural protein with 453 amino acids. Even though the nucleotide sequences were not identical, these seven megalocytiviruses were classified into one cluster and showed very high homology with red sea bream iridovirus (RSIV) with more than 97% identity. Thus, the seven iridovirus strains isolated from cultured marine fish in Taiwan were closer to the RSIV genotype than the infectious spleen and kidney necrosis virus genotype.

Macrobrachium rosenbergii nodavirus infection in M. rosenbergii (de Man) with white tail disease cultured in Taiwan

White tail disease (WTD) is a serious problem in Macrobrachium rosenbergii hatcheries and nursery ponds in Asia. The causative agents have been identified as M. rosenbergii nodavirus (MrNV) and its associated extra small virus. This is the first report demonstrating MrNV virus in M. rosenbergii displaying WTD signs in Taiwan by reverse transcriptase-polymerase chain reaction (RT-PCR). Amplified fragments of 850 and 425 bp for RNA-1 and RNA-2 of MrNV, respectively, were obtained by RT-PCR. RT-PCR products of about 850 and 1121 bp for RNA-1 and RNA-2 of MrNV were also obtained using different primer pairs. The amplicons were individually cloned into pGEM-T vector and sequenced. Using this recombinant plasmid of MrNV RNA-2 as DNA template, the non-radioactive DNA probes were prepared by PCR amplification with DIG-11-dUTP. The probes were used to successfully detect MrNV infection in the striated muscle tissues of WTD-diseased prawns using in situ hybridization. The 1121 bp genomic fragment of RNA-2 of MrNV consisted of a unique open reading frame with 1116 nucleotides, and it encoded a structural protein with 371 amino acids. The nucleotide sequence of the partial genome of MrNV RNA-2 revealed a 97% identity with an Indian isolate. A phylogenetic tree constructed using the nucleotide sequence of the viral capsid gene from insect and fish nodaviruses revealed that the MrNV Taiwan isolate could be interpreted as a new genus within the family Nodaviridae. However, its position showed more affinity with Alphanodavirus than with Betanodavirus. The study confirmed the presence of MrNV infection in freshwater prawns cultured in Taiwan suffering from WTD.

Effect of oxygen transfer on lipase production by Acinetobacter radioresistens

The influence of oxygen on alkaline lipase production by Acinetobacter radioresistens was studied under two operating modes: controlled dissolved oxygen (DO) concentration and controlled aeration rate. Compared with cell growth, the lipase production depended more extensively on oxygen. The intrinsic factor determining cell growth and lipase production was oxygen transfer rate (OTR) rather than DO concentration. Improvements in OTR, either by aeration or agitation, resulted in an increase in lipase yield and/or a reduction in fermentation time. The formation of A. radioresistens lipase could be described by a mixed-growth-associated model, and the enzyme was mainly a growth-associated product. The overall productivity for the lipase, which depended more strongly on agitation than aeration, could be related with kLa. DO concentration could not be employed in this correlation, though it has been useful as a criterion for ensuring no oxygen limitation in an aerobic fermentation.

Silk-induced asthma in children: a report of 64 cases

A total of 64 children less than 15 years of age with asthma caused by silk were studied. The diagnosis was based on a history of wheezing, positive skin tests to silk, positive conjunctival or nasal provocation tests, or serum IgE-Sw (silk waste). The average age of onset was 4 years 2 months. Sex ratio (M:F) was 3.6:1. A positive skin test is essential for the diagnosis. Conjunctival provocation tests were performed in 80% of cases because of reliability, safety, and convenience. The first symptom appeared an average of 10 months after initial exposure to silk. In 61% of patients, asthma was accompanied by allergic rhinitis but in only 14% of cases by conjunctivitis. In most cases, asthma occurred in winter, due to seasonal use of bed quilts or clothes filled with silk. Silk is a highly potent allergen. The average mean wheal diameter elicited by silk in prick testing was larger than two histamine equivalent prick tests. A cross reactivity exists among mulberry silk, and silkworm cocoons, batryticated silkworms, and silkworm chrysalis.

The use of bacteria as markers of leukemic lymphocytes and for the isolation of natural killer cells

Human lymphocyte subpopulations as well as leukemic lymphocytes can be identified and enumerated in blood smears by using bacteria that bind spontaneously to lymphocytes or by using bacteria to which antibodies are chemically coupled. The mechanism of natural binding of bacteria to lymphocytes was shown to involve a lectin on the lymphocyte surface and a carbohydrate on the bacteria. Also, we found that natural killer (NK) cells can be separated by negative selection using monolayers of bacteria. A subpopulation of T cells, identified by their binding of B. globigii, was shown to be suppressors for NK cells.