Comparison of Acute Kidney Injury During Treatment with Vancomycin and either Piperacillin-Tazobactam or Meropenem

CONTEXT

Empiric antibiotics are often required in hospitalized patients with serious infections who may be septic and at risk for drug resistant organisms. The purpose of this study was to evaluate the observed incidence of acute kidney injury (AKI) in a sample of adult patients receiving either piperacillin-tazobactam and vancomycin or meropenemvancomycin for at least 72 hours.

METHODS

Single-center, retrospective matched cohort at a 200-bed Regional Community Medical Center. Adult patients were included in the sample if they were without preexisting renal dysfunction and admitted over an 18-month time period to receive either the combination of piperacillin-tazobactam and vancomycin or meropenem-vancomycin. Sample patients were evaluated for AKI. This condition was defined by the authors as an increase in serum creatinine of 0.5mg/ml or an increase of 50% above baseline during the duration of antibiotic treatment.

RESULTS

A total of 266 patients receiving either combination of antibiotics were evaluated for AKI. The incidence of AKI was significantly higher in the piperacillin-tazobactam and vancomycin group (n = 74/292, 25%) compared with the meropenem-vancomycin group (n=8/74, 9.5%, p=0.008).

CONCLUSIONS

The results of this study suggest that the combination of piperacillin-tazobactam and vancomycin is associated with an increased incidence of AKI. Higher vancomycin trough concentrations were associated with increased risk for development of AKI.

Metal-binding hydrazone photoswitches for visible light reactivity and variable relaxation kinetics

The range of applications for photoswitching moieties is diverse, and the ability to design switches with variable photochemical and physical properties is consequently important for realizing their potential. Previously we reported on the photochromism of (E)-N'-(1-(2-hydroxyphenyl)ethylidene)isonicotinohydrazide (HAPI), an aroylhydrazone compound first developed as a transition metal chelator. Herein we report the synthesis of structurally related aroylhydrazone chelators and explore the effect of these modifications on their UVA, UVC and blue light photoreactivity, photostationary state composition, photoisomer thermal stability, and relative iron(iii) binding affinity. These findings will inform the next generation of aroylhydrazone photoswitches for metal-gated photoswitching applications.

[Phonological assessment and voice analysis of thyroid surgery patients]

Objective:To investigate the changes of speech and voice acoustics in patients with thyroid disease before and after operation, get objective values, and conducive to guiding the clinical diagnosis and treatment and recurrent laryngeal nerve protection. Method:A total of 216 patients undergoing thyroid surgery from October 2015 to October 2016 were treated with TVQ and GRBAS at 1 day before surgery, 1 week, 1 month, and 3 months postoperatively to phonological assessment, and Praat software was used to collect and analyze the acoustic acoustics index for preoperative and postoperative comparative analysis. Result:All patients did not damage the recurrent laryngeal nerve, unilateral or bilateral thyroid subtotal resection (no exploration of recurrent laryngeal nerve) in patients with postoperative speech and voice index F0 was decreased at 1 week after surgery (P<0.05), the other indicators did not change significantly; difference was found out in single-sided total thyroidectomy+ipsilateral central area lymph node dissection, bilateral thyroidectomy+unilateral central area lymph node dissection (exploration of unilateral recurrent laryngeal nerve) in patients with TVQ, GRBAS and F0, HNR after surgery 1 week compared with preoperative (P<0.05), However, there was no significant difference 3 months; TVQ, GRBAS and F0, HNR were significantly changed in patients with bilateral thyroidectomy+bilateral central lymph node dissection (revealed bilateral recurrent laryngeal nerve) at 1 week after operation (P>0.05). F0 and HNR were lower than those before operation, and the patients were treated with Jitter and Shimmer. The patients were treated with TVQ, GRBAS, Jitter and Shimmer before operation, however, the majority of patients' TVQ, GRBAS, Jitter, Shimmer can be restored to preoperative level after surgery 3 months (P>0.05). Conclusion:The appearance of speech and voice problems in patients after thyroid surgery may increase with the expansion of the surgical range, the change in speech and voice after neck lymph node dissection is reversible.

Differential Neuroproteomic and Systems Biology Analysis of Spinal Cord Injury

Acute spinal cord injury (SCI) is a devastating condition with many consequences and no known effective treatment. Although it is quite easy to diagnose traumatic SCI, the assessment of injury severity and projection of disease progression or recovery are often challenging, as no consensus biomarkers have been clearly identified. Here rats were subjected to experimental moderate or severe thoracic SCI. At 24h and 7d postinjury, spinal cord segment caudal to injury center versus sham samples was harvested and subjected to differential proteomic analysis. Cationic/anionic-exchange chromatography, followed by 1D polyacrylamide gel electrophoresis, was used to reduce protein complexity. A reverse phase liquid chromatography-tandem mass spectrometry proteomic platform was then utilized to identify proteome changes associated with SCI. Twenty-two and 22 proteins were up-regulated at 24 h and 7 day after SCI, respectively; whereas 19 and 16 proteins are down-regulated at 24 h and 7 day after SCI, respectively, when compared with sham control. A subset of 12 proteins were identified as candidate SCI biomarkers - TF (Transferrin), FASN (Fatty acid synthase), NME1 (Nucleoside diphosphate kinase 1), STMN1 (Stathmin 1), EEF2 (Eukaryotic translation elongation factor 2), CTSD (Cathepsin D), ANXA1 (Annexin A1), ANXA2 (Annexin A2), PGM1 (Phosphoglucomutase 1), PEA15 (Phosphoprotein enriched in astrocytes 15), GOT2 (Glutamic-oxaloacetic transaminase 2), and TPI-1 (Triosephosphate isomerase 1), data are available via ProteomeXchange with identifier PXD003473. In addition, Transferrin, Cathepsin D, and TPI-1 and PEA15 were further verified in rat spinal cord tissue and/or CSF samples after SCI and in human CSF samples from moderate/severe SCI patients. Lastly, a systems biology approach was utilized to determine the critical biochemical pathways and interactome in the pathogenesis of SCI. Thus, SCI candidate biomarkers identified can be used to correlate with disease progression or to identify potential SCI therapeutic targets.

[Impact of age-related cataract on regulation of circadian rhythm in elderly]

This review presented an introduction of the visual pathway related circadian rhythm regulation system: the intrinsically photosensitive retinal ganglion cells-suprachiasmatic nucleus-pineal gland-melatonin axis, and discussed the impact of light with different wave length and irradiation received by retina on circadian rhythm and sleep habit. A hypothesis was proposed consequently that the high morbidity of sleep disorder in elderly might be partially attributable to the long-term blue light blocking status induced by age-related cataract. A number of relative literatures were reviewed and a novel research direction was advanced on improving circadian rhythm and sleep condition in elderly based on the current knowledge. (Chin J Ophthalmol, 2016, 52: 309-314).

Follow-up observational study of "bi-ring method" breast surgery for treating hypermastia and mastoptosis

PURPOSE

This study investigated the efficacy and patient satisfaction of "bi-ring method" breast surgery in 46 patients with hypermastia and/or mastoptosis.

MATERIALS AND METHODS

A questionnaire survey, objective data measurements, visual analysis system survey, and various scoring scales were used to qualitatively and quantitatively assess the patients' indicators before and after surgery.

RESULTS

Statistical analysis showed the following: symptoms and signs in patients with macromastia improved significantly; all patients' breast shapes improved significantly and became more symmetrical and durable; all patients had minor hidden scars; the nipples and areolas had good feeling postoperatively, and there were relatively few mild complications.

CONCLUSIONS

The patients' overall satisfaction was high, indicating that the "bi-ring method" of breast plastic surgery could not only improve the breast shape and boast concealed scars but could significantly improve the patients' signs and symptoms of hypermastia, but the nipples and areolas had good postoperative feeling and there were few complications. Thus, this is a reasonable surgical approach that is worthy of promotion.

Supplementation dietary zinc levels on growth performance, carcass traits, and intramuscular fat deposition in weaned piglets

This study was conducted to estimate dietary zinc (Zn) levels on growth performance, carcass traits, and intramuscular fat (IMF) deposition in weaned piglets. Sixty piglets were randomly divided into five groups, as follows: control (basal diet), Zn250, Zn380, Zn570, and Zn760 with supplementation of 250, 380, 570, and 760 mg Zn/kg of the basal diet, respectively. The final weight, average daily gain (ADG), gain/feed (G/F), lean meat percentage, fat meat percentage, lean eye area, backfat thickness, and IMF content were dose-dependently increased in all groups of Zn treatment. The serum total triglycerides (TG) and free fatty acid (FFA) were significantly higher in all Zn treatments than in the control. The enzyme activities of lipoprotein lipase (LPL), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) were markedly higher, while enzyme activities of hormone-sensitive lipase (HSL) and carnitine palmitoyltransferase-1 (CPT-1) were significantly lower in all Zn treatments than in the control. The messenger RNA (mRNA) levels of sterol regulatory element-binding protein 1 (SREBP-1), stearoyl-CoA desaturase (SCD), FAS, ACC, peroxisome proliferator-activated receptor γ (PPARγ), LPL, and adipocyte fatty acid-binding protein (A-FABP) were significantly higher, while the mRNA levels of CPT-1 and HSL were significantly lower in all Zn treatments compared with the control. These results indicated that high levels of Zn increased IMF accumulation by up-regulating intramuscular lipogenic and fatty acid transport gene expression and enzyme activities while down-regulating lipolytic gene expression and enzyme activities.

Detection, differentiation, and VP1 sequencing of duck hepatitis A virus type 1 and type 3 by a 1-step duplex reverse-transcription PCR assay

Duck hepatitis A virus (DHAV) is an infectious pathogen causing fatal duck viral hepatitis in ducklings. Although both the inactivated vaccines and live attenuated vaccines have been used to protect ducklings, DHAV-1 and DHAV-3 still cause significant serious damage to the duck industry in China and South Korea. For rapid detection, differentiation, and epidemic investigation of DHAV in China, a genotype-specific 1-step duplex reverse-transcription (RT) PCR assay was established in this study. The sensitivity and specificity of the developed RT-PCR assay was evaluated with nucleic acids extracted from 2 DHAV reference strains, and 9 other infectious viruses and bacteria. The genotype-specific primers amplified different size DNA fragments encompassing the complete VP1 gene of the DHAV-1 or DHAV-3. The assay detected the liver samples collected from experimentally infected ducklings and dead ducklings collected from different regions of China. Sequence analysis of these DNA fragments indicated that VP1 sequences of DHAV-1 can be used to distinguish wild type and vaccine strains. The phylogenetic analysis of VP1 sequences indicated that the developed RT-PCR assay can be used for epidemic investigation of DHAV-1 and DHAV-3. The developed RT-PCR assay can be used as a specific molecular tool for simultaneous detection, differentiation, and sequencing the VP1 gene of DHAV-1 and DHAV-3, which can be used for understanding the epidemiology and evolution of DHAV.

Cladosporium cladosporioides Identified in China on Tobacco Seeds

Tobacco (Nicotiana tabacum L.) is a leafy, annual, solanaceous plant grown commercially for its leaves. China is the biggest single tobacco market and accounts for more than 40% of the global tobacco consumption (1). Tobacco seed harvested in Guiyang, Guizhou Province, China, are commonly contaminated or infected by various fungal pathogens, which can cause abnormal seedlings with dark brown lesions and stunting of roots and decayed seeds. In 2013, five samples of 500 seeds from tobacco cv. Guiyan 4 were tested for germination on moistened paper on petri dishes. On average, 35% of the seeds from all five samples developed into abnormal seedlings or were decayed and were plated onto potato dextrose agar media and grown for 5 days at 25°C in darkness to confirm the presence of a pathogen. However, one fungus was isolated from an average of 10% of the 500 seeds sampled. It was identified morphologically as Cladosporium cladosporioides (Fresen.) de Vries based on the velvety olive-brown with almost black reverse colony color and dimensions and color of conidia and conidiophores. Conidia formed in long branched chains that readily disarticulate, single celled, elliptical to limoniform, 2 to 8 (avg. 4.3) × 2 to 3 (avg. 2.1) μm. Conidia were pale to olive brown and smooth to verruculose. Ramoconidia were 0 to 1 septate, 7 to 14 (avg. 9.2) × 2 to 4 (avg. 2.6) μm, smooth or sometimes minutely verruculose. Conidiophores were pale to olive brown, macro- and micronemateus, smooth or sometimes verruculose, and of various lengths up to 320 μm long and 2 to 5 μm wide. Primer pair ITS1 and ITS4 was employed to amplify the regions of ITS1-5.8s-ITS2 of the pathogens. Sequences of all three isolates (G3, G10, and G18) (Accession Nos. KF841547, KF841554, and KF841560) were identical to each other and to four sequences in GenBank (JX230994.1, JQ768317.1, JQ768322.1, and AB763555.1). Pathogenicity of the three isolates of C. cladosporioides was verified on tobacco seedlings of 3-week-old grown on wet filter paper in the petri dishes (9 cm in diameter). For each isolate, 20 seedlings incubated in one plate were inoculated with 0.5 ml of a suspension of 10⁵ conidia/ml. Twenty seedlings were treated with sterile water as control treatment. After inoculation, the petri dishes were incubated at 25°C, 100 to 120 μEm^-2 S^-1, RH > 80%, and 16 h light per day for disease development. At 96 h after inoculation, symptoms comprising medium brown to black lesions on the roots were clearly visible on inoculated plants but not on the control plants. All seedlings inoculated died 9 days after inoculation whereas control seedlings remained symptomless. Re-isolation attempts on PDA from roots demonstrated C. cladosporioides to be present in symptomatic seedlings but not in roots of the control plants. Moreover, the characteristics of the cultured fungi were exactly the same as those originally isolated. Isolates G3, G10, and G18 (KF841547, KF841554, and KF841560) were deposited with the Tobacco Diseased Fungi, Guizhou Academy of Tobacco Sciences, Guizhou, China. Previously, C. cladosporioides has also been isolated from macadamia (Macadamia integrifolia Maiden & Betche) racemes in South Africa (4), from diseased papaya (Carica papaya L.) in Taiwan province of China (2), and from seeds of Amaranthus spp. in Poland (3). To the best of our knowledge, this is the first report of C. cladosporioides causing seed disease on tobacco in China and the disease should be considered in existing disease management practices. References: (1) British American Tobacco Annual Report, 8, 2012. (2) R. S. Chen, et al. Plant Dis. 93:426, 2009. (3) W. Pusz. Phytopathologia 54:15, 2009. (4) N. van den Berg et al. Plant Dis. 92:484, 2008.

Bioinformatic analysis and characteristics of glycoprotein C encoded by the newly identified UL44 gene of duck plague virus

Glycoprotein C is one of the duck plague virus (DPV) glycoproteins and is encoded by the DPV UL44 gene. DPV glycoprotein C (DPV-gC) comprises 431 amino acids with a putative molecular mass of 47.35 kDa. Sequence analysis indicated that the protein possesses typical characteristics of type-I membrane glycoproteins, containing an N-terminal signal sequence, an external domain, a C-terminal membrane anchor region, and a short cytoplasmic domain. Comparisons of 22 alphaherpesvirus-gC protein sequences revealed eight conservative Cys-residue sites, which may play a crucial role in the biological functions and structural stabilization of the DPV-gC protein. Estimates of potential antigenic epitopes and secondary structure identified four B cell dominant epitopes, which are located at amino acids 68-71, 87-91, 369-352, and 372-374. A model for the structure of DPV-gC was derived by associating its predicted secondary and three-dimensional structures. In conclusion, these results will provide a basis for further functional studies of DPV-gC, establishing novel clinical diagnoses of DPV, and in the development of a new DPV vaccine.

Comparison of FIB-4 and APRI in Chinese HBV-infected patients with persistently normal ALT and mildly elevated ALT

Significant liver disease has been reported in chronic hepatitis B patients with normal alanine aminotransferase (ALT). Liver biopsy (LB) is the current gold standard for assessing hepatic inflammation and fibrosis in patients with chronic HBV. However, associated risks have led to the development of noninvasive models. Their utility in patients with normal ALT is unknown. FIB-4 and aspartate aminotransferase (AST)-to-platelet ratio index (APRI) were calculated for patients with chronic HBV infection undergoing biopsy. The performance of each model and AUROC for predicting significant fibrosis (Scheuer's score ≥ S2) were determined for the entire cohort and stratified by elevated (≥50 U/L) and normal ALT. Two-hundred and thirty-one liver biopsies were included. The number of patient with normal ALT was 140, and 22.1% had significant fibrosis. The AUROC curve for patients with normal ALT was 0.81 for FIB-4 and 0.80 for APRI, compared with 0.71 for FIB-4 and 0.72 for APRI for those with mildly elevated ALT level. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FIB-4 were 0.63, 0.88, 0.61 and 0.93, for patients with normal ALT; the values for APRI were 0.40, 0.88, 0.33 and 0.93. Both FIB-4 and APRI are useful for identification of those without significant fibrosis. However, because they have poor PPV, LB will continue to be used for assessment of HBV-infected patients with normal ALT and mildly elevated ALT.

Adhesion and invasion to duck embryo fibroblast cells by Riemerella anatipestifer

Here, we investigated adhesion and invasion of Riemerella anatipestifer (RA) to primary duck embryo fibroblast (DEF) cells. The ability of RA to adhere to, and more importantly, to invade DEF cells was demonstrated by using a gentamicin invasion assay and was confirmed by transmission electron microscopy (TEM). Adhesion of RA could be found by TEM after 1 h of inoculation. Both apoptosis and necrocytosis of DEF were indicated by TEM after 10 h of incubation, which suggested a complex mechanism of DEF cell death induced by RA. Our results showed that internalized RA had the ability to leave the DEF cells. Inhibition studies indicated that RA proteins play a role in adhesion. Moreover, invasion of RA to DEF cells was shown to require rearrangement of actin microfilaments and microtubular cytoskeletal elements. Because the adhesion and invasion ability of RA to DEF cells could be demonstrated in vitro, similar processes might occur in vivo, where DEF cells play a crucial role in the diffusion of RA in ducks.

Clostridium difficile infection and limitations of markers for severity in patients with hematologic malignancy

OBJECTIVE

To describe characteristics of Clostridium difficile infection (CDI) and markers of severe CDI among patients with hematologic malignancies.

DESIGN

Case-control study.

SETTING

Tertiary care teaching hospital.

PATIENTS AND METHODS

Inpatients with hematologic malignancies and CDI were age and time matched with 2 control inpatients without hematologic malignancies. Chart reviews were performed, and C. difficile isolates were strain typed.

RESULTS

Case patients (n = 41) and control patients (n = 82) patients were different in respect to receipt of immunosuppressive agents within 2 months (92.7% vs 25.6%; P < .0001); neutropenia within 2 months (75.6% vs 3.7%; P < .0001) and mean (± standard deviation) white blood cell (WBC) count at diagnosis (vs 4.9 ± 14.1 vs 11.8 ± 6.8 x 10(3) cells/mL; P <.0001); baseline mean creatinine level (0.89 ± 0.1 vs 1.6 ± 2.4 mg/dL; P = .003), mean creatinine level at diagnosis (0.83 ± 0.4 vs 1.85 ± 1.9 mg/dL; P = .004), and creatinine increases of 1.5 times over baseline (2.4% vs 15.1%; P = .02). Immunosuppressive agents and creatinine level remained significant in multivariable analysis (P = .03 for both variables). Severity correlated with mortality when measured by alternate severity criteria but not when measured by the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America criteria, which are based solely on WBC count and creatinine elevation. The prevalence of the epidemic BI/NAP1/027 strain was similar in both groups.

CONCLUSIONS

Patients with hematologic malignancies had lower creatinine levels at the time of CDI diagnosis compared with control patients. WBC counts also tended to be lower in case patients. CDI severity criteria based on WBC count and creatinine level may not be applicable to patients with hematologic malignancies.

Phylogenetic analysis of parvoviruses isolated in Taiwan from ducks and geese

Two major outbreaks of parvovirus infection occurred in domestic waterfowls in Taiwan in the last two decades; the first was in 1982 and the second in 1989/1990. Parvoviruses isolated in the two outbreaks were sequenced between nucleotides 142 and 680 of the VP3 gene. Sequence comparisons reveal that these viruses could be divided into two groups respectively related to goose parvovirus (GPV) and Muscovy duck parvovirus (MDPV). Nucleotide differences between ''GPV'' and ''MDPV'' groups range from 16.2% to 19.4%. In comparison, the differences within the ''GPV'' group are only 0-6.5%, while those within the ''MDPV'' group are only 0.2-1.7%. Phylogenetic analysis reveals that parvoviruses isolated in the 1982 outbreak in Taiwan are all GPV-related, whereas those isolated in the 1989/1990 outbreak are all MDPV-related. GPV-related isolates from Taiwan were separated into two groups, Thai group and European group. In comparison, all MDPV-related isolates from Taiwan are clustered in a single group that is closely related to a French MDPV isolate. The MDPV-related infection in Taiwan occurred at almost the same time in 1989 as the MDPV outbreak in France. The close phylogenetic relationship between the ''MDPV'' Taiwanese isolates and the French MDPV isolate exhibited on the VP3 fragment investigated suggests that they should be compared more deeply, to look for a possible common origin. The MDPV-related 1985 isolate might be a candidate.

Experimental demonstration of packet-rate 10-Gb/s OOK OSNR monitoring for QoS-aware cross-layer packet protection

A cross-layer network platform may enable introspective access to the physical layer, allowing optical performance monitoring measurements to feedback to higher layers for packet rerouting and protection. We experimentally demonstrate quality-of-service-aware packet protection that leverages cross-layer signaling based on the monitoring of packets' optical-signal-to-noise ratio. In order to detect degraded data streams, the monitoring system is based on a delay-line Mach-Zehnder interferometer and a field-programmable gate array. The system is realized in an experimental cross-layer enabled optical packet switched fabric, measuring the optical-signal-to-noise ratio for 10-Gb/s OOK streams. The packet protection scheme uses the dynamic performance measurements to actuate a rerouting of high-quality-of-service packets. 8 × 10-Gb/s wavelength-striped optical messages are rerouted through the fabric error-free (bit-error rates less than 10(-12)).

Efficacy study and field application of an inactivated new type gosling viral enteritis virus vaccine for domestic geese

New type gosling viral enteritis virus (NGVEV) caused a serious disease in naive juvenile goslings. In the described studies the performance of 2 vaccines was analyzed: a vaccine containing adjuvanted inactivated NGVEV and a vaccine containing adjuvanted inactivated NGVEV and recombinant goose IL-2. Breeder geese were subcutaneously vaccinated at the beginning of the egg production period with the vaccines. Breeder geese sham vaccinated with PBS served as control. The cellular and humoral immune responses of the vaccinated breeder geese, as well as the presence of maternally derived antibody to NGVEV, were investigated by ELISA, virus neutralization test, and lymphocyte proliferation assay, respectively. A significantly higher immunogenicity (P < 0.05) was induced by the inactivated NGVEV-recombinant goose IL-2 adjuvant vaccine compared with the inactivated NGVEV vaccine. The offspring of the vaccinated birds were challenged with virulent NGVEV (100 50% lethal dose) and the protective efficacy of the vaccines was determined. Furthermore, in a field trial the efficacy of the inactivated NGVEV vaccine was recorded from years 2003 to 2007. No clinical signs or abnormal health status were observed in the vaccinated breeder geese and the progeny. After a single application, >80% protection was shown in the progeny of geese vaccinated against NGVEV challenge for approximately 5 mo. The extensive field trials further demonstrated that vaccination of breeder geese with the inactivated NGVEV vaccine could be a safe and efficacious means to control NGVE disease. Moreover, the level of maternally derived NGVEV antibody titer in the egg yolk reflected the level of NGVEV antibodies in the breeder geese, suggesting that the egg yolk could be used to monitor the vaccination efficacy in commercial goose breeder flocks.

Development and application of an indirect immunohistochemical method for the detection of duck plague virus vaccine antigens in paraffin sections and localization in the vaccinated duckling tissues

The objective of the present study was to develop and apply a streptavidin-alkaline phosphatase labeling system of indirect immunohistochemistry (SP-IHC) to detect antigenic distribution and localization regularity of duck plague virus (DPV) vaccine antigens in paraformaldehyde-fixed paraffin-embedded tissues of experimentally vaccinated ducklings. Male New Zealand rabbits were immunized with purified DPV antigens, which were engaged by a combination of differential centrifugation and sucrose-density gradient ultracentrifugation. The rabbit anti-DPV polyclonal antibodies were purified and used as the primary antibodies. Forty-eight 28-d-old DPV-free Pekin ducklings were subcutaneously inoculated with attenuated DPV vaccine in the immunization group and sterile PBS in the control group. The tissues were collected at sequential time points between 4 h and 18 wk postvaccination (PV) and were prepared for SP-IHC observation. The presence of DPV-specific antigens was first observed in the liver and spleen at 12 h PV; in the bursa of Fabricius, thymus, Harderian gland, esophagus, and intestinal tract at 1 d PV; and in the heart, lung, kidney, pancreas, and brain at 3 d PV. The positive staining reaction could be detected in the vaccinated duckling tissues until 18 wk PV, and no positive staining cells could be observed in the controls. The highest levels of positive staining reaction were found in the liver, spleen, bursa of Fabricius, thymus, and intestinal tract, whereas a few DPV vaccine antigens were distributed in the heart, pancreas, and esophagus. The target cells had a ubiquitous distribution, especially in the mucosal epithelial cells, lamina propria cells, macrophages, hepatocytes, and lymphocytes, which served as the principal sites for antigen localization. These findings demonstrated that SP-IHC was a reliable method for detecting antigenic distribution and localization regularity of DPV vaccine antigens in routine paraffin sections. The present study may be useful for describing proliferation and distribution regularity of DPV vaccine in the vaccinated duckling tissues and enhance further studies and clinical application of attenuated DPV vaccine.

Humoral and cellular immune responses in adult geese induced by an inactivated vaccine against new type gosling viral enteritis virus

To assess the immunogenicity of an inactivated new type gosling viral enteritis virus (NGVEV) vaccine, we investigated 3 different doses of the inactivated vaccine and the inactivated vaccine in conjunction with 3 different doses of recombinant goose interleukin-2 (rGoIL-2) adjuvant. A virus concentration of 10(5) 50% embryo infective dose/mL was subcutaneously inoculated into adult geese divided into 6 groups. The dynamic changes of the humoral and cellular immunity responses elicited by the vaccines in the adult geese postvaccination (PV) were investigated using ELISA, virus neutralization test, and lymphocyte proliferation assay. The clearance of virus from the intestines of geese (175 d PV) was studied by histopathological examination and indirect immunofluorescence assay after virulent NGVEV challenge. This study showed that the inactivated NGVEV vaccine elicits strong humoral and cellular responses in the vaccinated adult geese. The absorbance values of specific anti-NGVEV antibodies, the neutralization antibody titer, and the lymphocyte proliferation index rapidly increased, peaked at about 28 d PV, progressed to the plateau stage, and then decreased slightly. The rGoIL-2 adjuvant enhanced the immune response, and this adjuvant in conjunction with the inactivated NGVEV vaccine induces a significantly higher specific anti-NGVEV antibody absorbance value, neutralization antibody titer, and lymphocyte proliferation index than the non-adjuvant-inactivated NGVEV vaccine (P < 0.05). The inactivated NGVEV vaccine conferred adequate efficient ability to clear NGVEV in vaccinated geese even in the last phase of the vaccination period (175 d PV). The inactivated NGVEV vaccine (0.5 mL/goose) with 1,000 units of rGoIL-2 adjuvant/goose is the most effective dose, thereby eliciting the strongest humoral and cellular immunity responses and providing the most efficacious clearance of NGVEV in vivo.

Source reconstruction of brain electromagnetic fields--source iteration of minimum norm (SIMN)

A recursive scheme aiming at obtaining sparse and focal brain electromagnetic source distribution is proposed based on the interpretation that the weighted minimum norm is the minimum norm estimates of amplitudes on grid points for the source distribution specified by the diagonal elements of the weight matrix. The source distribution is updated so that, at each grid point, the number of current dipoles equals the total source strength estimate of the pre-specified current dipoles. The source strength of a pre-specified current dipole is estimated by projecting the vector of minimum norm estimate to the space spanned by the three column vectors, corresponding to the three amplitudes of the current dipole, of the resolution matrix. The norm of the projected vector yields the source strength estimate of the current dipole. Exact inverse solutions are obtained by this source iteration of minimum norm (SIMN) algorithm for noiseless MEG signals from multi-point sources provided the sources are sufficiently sparse and there are no substantial cancellations among the signals of the sources. For noisy data, a set of "noise sources" is introduced. The diagonal matrix formed by the "noise source numbers" plays the role of regularization matrix and Tikhonov regularization is applied to initialize the "noise source numbers". Application to the source localization of real EEG data is also presented.

Quantitative analysis of Salmonella Enteritidis loads in ducklings after nasal inoculation

The distribution patterns of Salmonella Enteritidis in systemic organs, which have not been described previously, should be studied to better understand its pathogenesis in vivo. We inoculated the ducklings with Salmonella Enteritidis via the nasal route and performed a real-time PCR assay for determining the concentration of Salmonella Enteritidis DNA and studied the histopathology of various tissues postinoculation. The results show that the Salmonella Enteritidis load in systemic organs has a close correlation with the progression of disease. Further, rapid dissemination and active replication of Salmonella Enteritidis in multiple systemic organs accelerated the progression of disease.

The pathogenesis of Salmonella enteritidis in experimentally infected ducks: a quantitative time-course study using taqman polymerase chain reaction

Ducks were subcutaneously infected with a high-virulence strain of Salmonella enterica ssp. enterica serovar Enteritidis (Salmonella Enteritidis). The kinetics of the Salmonella Enteritidis genomic DNA loads, the immunohistochemical localization of the bacterial antigens, and the histopathological examination in various tissues were investigated. The results showed that the time course of the appearance of the Salmonella Enteritidis bacterial antigens and the lesions in various tissues was coincident with the bacterial load of the organism in various infected tissues. This suggests that Salmonella Enteritidis loads in systemic organs are closely correlated with the progression of the infection.

Replication kinetics of Salmonella enteritidis in internal organs of ducklings after oral challenge: a quantitative time-course study using real-time PCR

This research was undertaken to understand the replication kinetics of Salmonella enteritidis (S. enteritidis) in the internal organs of ducklings after oral challenge over a 2 wk period. A serovar-specific real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) assay was used to detect genomic DNA of S. enteritidis in the blood and the internal organs at different time points respectively. The results showed that the spleen was positive at 12 h post inoculation (PI) and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, the pancreas and kidney were positive at 20 h PI, and the final organ to show a positive results was the gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24 h-36 h PI, with the liver and spleen containing the highest concentration of S. enteritidis. The blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 2 wk for the spleen without causing apparent symptoms. To make the results meaningful, a side-by-side bacteriology method (IFA) was performed. The results of IFA were similar to the FQ-PCR assay. This research provided a significant data for understanding the life cycle of S. enteritidis in the internal organs, and may help to understand the pathogenesis of S.entertidis in the future.

Electron field emission characteristics and field evaporation of a single carbon nanotube

Direct transmission electron microscope (TEM) observations of the field emission and evaporation process of emitting carbon nanotubes (CNTs) shown that the tip structure of the CNT is in general composed of irregular shaped graphitic sheets which extend typically more than 10 nm from the end of the CNT. It is found that the irregular shaped graphitic sheets at the tip of the CNT may greatly enhance the field emission characteristics of the CNT when compared with that having an ideal circular edge. The field evaporation of the CNT proceeds typically via the removal of the irregular shaped graphitic sheets from the tip of the CNT, and field emission characteristics of a CNT depend far more sensitively on the tip structure than on the geometric length of the CNT.

NAD(+) and axon degeneration revisited: Nmnat1 cannot substitute for Wld(S) to delay Wallerian degeneration

The slow Wallerian degeneration protein (Wld(S)), a fusion protein incorporating full-length nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1), delays axon degeneration caused by injury, toxins and genetic mutation. Nmnat1 overexpression is reported to protect axons in vitro, but its effect in vivo and its potency remain unclear. We generated Nmnat1-overexpressing transgenic mice whose Nmnat activities closely match that of Wld(S) mice. Nmnat1 overexpression in five lines of transgenic mice failed to delay Wallerian degeneration in transected sciatic nerves in contrast to Wld(S) mice where nearly all axons were protected. Transected neurites in Nmnat1 transgenic dorsal root ganglion explant cultures also degenerated rapidly. The delay in vincristine-induced neurite degeneration following lentiviral overexpression of Nmnat1 was significantly less potent than for Wld(S), and lentiviral overexpressed enzyme-dead Wld(S) still displayed residual neurite protection. Thus, Nmnat1 is significantly weaker than Wld(S) at protecting axons against traumatic or toxic injury in vitro, and has no detectable effect in vivo. The full protective effect of Wld(S) requires more N-terminal sequences of the protein.

Quantitative Analysis of Electron Field-Emission Characteristics of Individual Carbon Nanotubes: The Importance of the Tip Structure

Electron field-emission measurements on individual carbon nanotubes (CNTs) were performed inside the transmission electron microscope (TEM). The field-emission characteristics of CNTs with different tip structures were compared, and their field conversion factor and emission area were studied systematically. It was found that the field-emission characteristics of a CNT depend sensitively on its tip structure, and in particular an opened CNT was shown to be superior to a capped CNT. High-resolution TEM observations revealed that the tip of an opened CNT may, in general, be regarded as being composed of irregular shaped graphitic sheets, and these graphitic sheets have been found to improve dramatically the field-emission characteristics, but the sharp edge may result in larger error in the calculated emission area. The influence of uncertainty in the work function of the CNTs on the field conversion factor and emission area calculation was also investigated.