bluuebunny/crossref_metadata_2025_split huggingface dataset:
Replacement of a Natural Diet by a Prepared Dry Feed for Successful Maturation and Spawning of Female Litopenaeus vannamei (Boone) Broodstock
Authors: Du Shaobo , Hu Chaoqun , Shen Qi 
Published: April 2007

AbstractA prepared dry feed containing bloodworm meal Glycera chirori Izuka and oyster meal Crassostrea rivularis Gould, together with a natural diet consisting of G. chirori and shelled C. rivularis (1:1 ratio) and a mixed diet consisting of the prepared dry feed and the natural diet in equal proportion were evaluated as broodstock diets for female Pacific white shrimp Litopenaeus vannamei‐ (Boone). Results showed that shrimp fed the prepared dry feed gave higher maturation ratio and significantly higher hepatosomatic index (HSI) values (P < 0.05) than those fed the natural diet and the mixed diet. The prepared dry feed and the mixed diet induced higher total spawn numbers and significantly higher average daily spawns per female than the natural diet (P < 0.05), while the gonadosomatic index (GSI) values and fecundity (eggs per spawn) were not significantly affected by these diets. Results of this study showed that both the prepared dry feed and the mixed diet outperformed the natural diet to improve the spawning performance of female L. vannamei, and that using G. chirori meal and C. rivularis meal as the main ingredients of the prepared dry feed would be an effective way to promote the broodstock nutrition.
Effects of Artificial Substrate and Stocking Density on the Nursery Production of Pacific White Shrimp Litopenaeus vannamei
Authors: Moss Komarey R. K. , Moss Shaun M. 
Published: April 2007

AbstractNursery production may be enhanced by the addition of artificial substrate to increase the surface area upon which shrimp graze and to serve as refuge. The objective of this study was to assess the effects of the artificial substrate, AquaMatsTM, on the performance of postlarval Pacific white shrimp Litopenaeus vannamei stocked at three densities. Eighteen 230‐L tanks were stocked with 10‐d postlarvae (mean weight < 0.01 g). Six treatments were evaluated and consisted of shrimp stocked at three densities (778 shrimp/m2, 1,167 shrimp/ m2, and 1,556 shrimp/m2) with and without access to artificial substrate. Shrimp in all treatments received a commercial diet ad libitum. After 6 wk, shrimp were harvested from each nursery tank, counted, and batch weighed. Mean final weight, survival, production, feed conversion ratio, and water quality parameters were analyzed by 2‐way ANOVA. There were highly significant (P < 0.001) density and substrate effects on final weight, but there was no significant interaction effect. Final weight was 26.0, 17.4, and 34.5% greater in treatments with substrate than without substrate when stocked at 778, 1,167, and 1,556 shrimp/m2, respectively. There was no significant density, substrate, or interaction effect on survival or water quality. Mean survival was ± 89.1% for all treatments. Increased shrimp growth in the presence of added substrate was likely due to the availability of attached particulate organic matter on the AquaMatsTM that served as an additional food source. Results from this study indicate that artificial substrate can be used to mitigate the potential negative effects of high stocking density on growth of L. vannamei in nursery systems.
Significant Increase in Survival of Captive‐bred Juvenile Banggai Cardinalfish Pterapogon kauderni with an Essential Fatty Acid‐Enriched Diet
Authors: Vagelli Alejandro A. 
Published: April 2007

Abstract Pterapogon kauderni is an endemic, direct developing, coral reef fish from Indonesia, which has become very popular in the aquarium community. During development of a captive breeding program, high frequency of shock syndrome events and associated mortality was observed in juveniles fed a diet of newly hatched Anemia. After about a week post‐release, juveniles became extremely sensitive to external stimuli, such as feeding and turning the lights on. A series of five tests (mean duration = 116 d) were conducted to investigate a possible dietary essential fatty acid deficiency. A significant increase in survival (P < 0.001) and decrease in frequency of shock syndrome events (P < 0.05) were observed in juveniles fed a highly unsaturated fatty acid‐enriched diet. Juveniles fed the un‐enriched diet suffered a mean of 1.4 events/ individual, whereas those fed the enriched diet had a significantly lower mean of 0.08 (P < 0.001). Mean mortality (all tests) for juveniles fed the un‐enriched diet was 80.7%. whereas it was 5.3% for those fed the enriched diet. No individual fed the enriched diet died after suffering a shock event, whereas in four out of five tests several individuals (mean = 2.26) fed the un‐enriched diet died a few minutes after the event. No event was observed during the first week after juvenile release: the mean days at which the first event occurred (all tests) were 26.8 (un‐enriched) and 26 (enriched). and the mean week at which the highest frequency of shock events occurred was 4.7 (un‐enriched). The results of this study have particular significance for conservation because of the threatened status of P. kauderni.
Optimization of Artemia Metanauplii on Growth and Survival of Gilthead Sea Bream Larvae Sparus aurata
Authors: Mihelakakis Apostolos , Tsolkas Christos , Yoshimatsu Takao 
Published: April 2007

Abstract–Growth, feed efficiency and survival of gilthead sea bream Sparus aurata larvae fed exclusively various levels of enriched Artemia during the period 25 DPH‐34 DPH were investigated. Larvae had an average initial fresh body weight (BW) of 4.99 mg and were fed on Artemia at rates of 20, 35, 50, 65, and 80% of their body weight per day, in two equal meals. Each ration was administered to duplicate groups of 1,000 larvae, with ration readjusted every second day. Feeding rate had a significant effect on larval survival, which was lower in larvae fed the 20 and 35% BS/d rations. The specific growth rate (SGR) showed a curvilinear significant increase when the feeding rate was increased from 20 to 65% BW/d, but there was no improvement when the feeding rate was increased from 65 to 80% BW/d. Percent feed efficiency (FE) decreased significantly from a maximum value at 20% ration to 80% BW/d but at 65% and 80% rations the values of FE were not significantly different. Optimum ration (minimum quantity of Artemia concomitant with maximum larval growth) was estimated close to 65% BW/d. The significance of the results is discussed in relation to potential economics of Artemia cysts use in commercial hatcheries.
Spawning Characteristics of the South African Mudcrab Scylla serrata (Forskål) in Captivity
Authors: Davis Jerome A. , Churchill Giles J. , Hecht Thomas , Sorgeloos Patrick 
Published: April 2007

Abstract Scylla serrata is a potential aquaculture species in Southern Africa. Information about its reproductive biology is required as a prerequisite to establishing hatchery technology. Adult female S. serrata were caught in the Umlalazi estuary on the subtropical east coast of South Africa and kept in captivity to observe and record spawning characteristics. Data collected included crab size and mass, time in captivity prior to spawning, fecundity per batch, relative fecundity, individual egg mass and size, size of zoea 1 larvae, incubation time, and hatch success rate. Of the 119 crabs kept in captivity 83% spawned in the maturation system– most within 40 d of capture. The crabs were highly fecund (mean relative fecundity per batch = 10,655 ± 4,069 eggs/g female) and the majority of the batches hatched within 288 h (12 d) at 27 C. Spawning in captivity occurred throughout the year, with a peak in late winter/early spring. This differs slightly from records of ovarian maturity stages of the crabs in the wild. A pattern of synchronous spawning was recorded where the females were observed to extrude their eggs in groups, commonly within 3 d of one another, separated by long periods of inactivity, suggesting an exogenous spawning cue. A total of 1,374,488 zoea larvae were obtained per kg of female per month. This means that if sufficient mature females can be caught from the wild, these could be used for stocking hatchery operations. The crabs were easy to maintain, mature, and spawn in captivity. This will facilitate future domestication which will eventually reduce the need for wild caught broodstock. The spawning characteristics of South African 5. serrata At in well with those observed for the genus throughout its distribution implying that ecological and fisheries management could be similar.
In Vitro Study of Flow Regulation for Pulmonary Insufficiency
Authors: Camp T. A. , Stewart K. C. , Figliola R. S. , McQuinn T. 
Published: April 2007

Abstract
Given the tolerance of the right heart circulation to mild regurgitation and gradient, we study the potential of using motionless devices to regulate the pulmonary circulation. In addition, we document the flow performance of two mechanical valves. A motionless diode, a nozzle, a mechanical bileaflet valve, and a tilting disk valve were tested in a pulmonary mock circulatory system over the normal human range of pulmonary vascular resistance (PVR). For the mechanical valves, regurgitant fractions (RFs) and transvalvular pressure gradients were found to be weak functions of PVR. On the low end of normal PVR, the bileaflet and tilting disk valves fluttered and would not fully close. Despite this anomaly, the regurgitant fraction of either valve did not change significantly. The values for RF and transvalvular gradient measured varied from 4 to 7% and 4to7mmHg, respectively, at 5lpm for all tests. The diode valve was able to regulate flow with mild regurgitant fraction and trivial gradient but with values higher than either mechanical valve tested. Regurgitant fraction ranged from 2 to 17% in tests extending from PVR values of 1to4.5mmHg∕lpm at 5lpm and with concomitant increases in gradient up to 17mmHg. The regurgitant fraction for the nozzle increased from 2 to 23% over the range of PVR with gradients increasing to 18mmHg. The significant findings were: (1) the mechanical valves controlled regurgitation at normal physiological cardiac output and PVR even though they failed to close at some normal values of PVR and showed leaflet flutter; and (2) it may be possible to regulate the pulmonary circulation to tolerable levels using a motionless pulmonary valve device.
Antimicrobial Susceptibilities of
Peptostreptococcus anaerobius
and the Newly Described
Peptostreptococcus stomatis
Isolated from Various Human Sources
Authors: Könönen Eija , Bryk Anne , Niemi Päivi , Kanervo-Nordström Arja 
Published: April 2007

ABSTRACT

Peptostreptococcus anaerobius
sensu lato, currently including two closely related species,
P. anaerobius
and
P. stomatis
, is known to be more resistant than other gram-positive anaerobic cocci. We reidentified potential
Peptostreptococcus
isolates and tested their susceptibilities to eight antimicrobials. Notably,
P. anaerobius
had constantly higher values for the MIC at which 50% of the isolates are inhibited (MIC
50
) and the MIC
90
than
P. stomatis
.
Targeted Drug-Carrying Bacteriophages as Antibacterial Nanomedicines
Authors: Yacoby Iftach , Bar Hagit , Benhar Itai 
Published: April 2007

ABSTRACT

While the resistance of bacteria to traditional antibiotics is a major public health concern, the use of extremely potent antibacterial agents is limited by their lack of selectivity. As in cancer therapy, antibacterial targeted therapy could provide an opportunity to reintroduce toxic substances to the antibacterial arsenal. A desirable targeted antibacterial agent should combine binding specificity, a large drug payload per binding event, and a programmed drug release mechanism. Recently, we presented a novel application of filamentous bacteriophages as targeted drug carriers that could partially inhibit the growth of
Staphylococcus aureus
bacteria. This partial success was due to limitations of drug-loading capacity that resulted from the hydrophobicity of the drug. Here we present a novel drug conjugation chemistry which is based on connecting hydrophobic drugs to the phage via aminoglycoside antibiotics that serve as solubility-enhancing branched linkers. This new formulation allowed a significantly larger drug-carrying capacity of the phages, resulting in a drastic improvement in their performance as targeted drug-carrying nanoparticles. As an example for a potential systemic use for potent agents that are limited for topical use, we present antibody-targeted phage nanoparticles that carry a large payload of the hemolytic antibiotic chloramphenicol connected through the aminoglycoside neomycin. We demonstrate complete growth inhibition toward the pathogens
Staphylococcus aureus
,
Streptococcus pyogenes
, and
Escherichia coli
with an improvement in potency by a factor of ∼20,000 compared to the free drug.
Dissemination of
Acinetobacter baumannii
Clones with OXA-23 Carbapenemase in Colombian Hospitals
Authors: Villegas Maria Virginia , Kattan Juan Nicolas , Correa Adriana , Lolans Karen , Guzman Ana Maria , Woodford Neil , Livermore David , Quinn John P. 
Published: April 2007

ABSTRACT

During 2005, 66 carbapenem-resistant isolates of
Acinetobacter baumannii
were collected from seven tertiary-care hospitals participating in a nationwide surveillance network in Colombia. The isolates were multidrug resistant and produced the carbapenemases OXA-23 and OXA-51. Forty-five belonged to four clones while 21 were unique pulsotypes. One clone was present in two hospitals within one city, while another had spread between two hospitals in different cities. Blood, secretions, and abdominal fluids were the most frequent sites of isolation. This is the first description of widespread dissemination of OXA-23 in South America.
Efficacy of Tachyplesin III, Colistin, and Imipenem against a Multiresistant
Pseudomonas aeruginosa
Strain
Authors: Cirioni Oscar , Ghiselli Roberto , Silvestri Carmela , Kamysz Wojciech , Orlando Fiorenza , Mocchegiani Federico , Di Matteo Fabio , Riva Alessandra , Łukasiak Jerzy , Scalise Giorgio , Saba Vittorio , Giacometti Andrea 
Published: April 2007

ABSTRACT

An experimental study has been performed to compare the in vitro activity and the in vivo efficacy of tachyplesin III, colistin, and imipenem against a multiresistant
Pseudomonas aeruginosa
strain. In vitro experiments included MIC determination, time-kill, and synergy studies. For in vivo studies, a mouse model of sepsis has been used. The main outcome measures were bacterial lethality, quantitative blood cultures, and plasma levels of lipopolysaccharide, tumor necrosis factor alpha, and interleukin-6. The combination of tachyplesin III or colistin with imipenem showed in vitro synergistic interaction. A significant increase in efficacy was also observed in vivo: combination-treated groups had significantly lower levels of bacteremia than did groups treated with a single agent. Tachyplesin III combined with imipenem exhibited the highest efficacy on all main outcome measurements. These results highlight the potential usefulness of these combinations and provide therapeutic alternatives for serious infections caused by gram-negative bacteria in the coming years.
Differential Interaction of Dendritic Cells withRickettsia conorii: Impact on Host Susceptibility to Murine Spotted Fever Rickettsiosis
Authors: Fang Rong , Ismail Nahed , Soong Lynn , Popov Vsevolod L. , Whitworth Ted , Bouyer Donald H. , Walker David H. 
Published: April 2007

ABSTRACTSpotted fever group rickettsioses are emerging and reemerging infectious diseases, some of which are life-threatening. In order to understand how dendritic cells (DCs) contribute to the host resistance or susceptibility to rickettsial diseases, we first characterized the in vitro interaction of rickettsiae with bone marrow-derived DCs (BMDCs) from resistant C57BL/6 (B6) and susceptible C3H/HeN (C3H) mice. In contrast to the exclusively cytosolic localization within endothelial cells, rickettsiae efficiently entered and localized in both phagosomes and cytosol of BMDCs from both mouse strains.Rickettsia conorii-infected BMDCs from resistant mice harbored higher bacterial loads compared to C3H mice.R. conoriiinfection induced maturation of BMDCs from both mouse strains as judged by upregulated expression of classical major histocompatibility complex (MHC) and costimulatory molecules. Compared to C3H counterparts, B6 BMDCs exhibited higher expression levels of MHC class II and higher interleukin-12 (IL-12) p40 production upon rickettsial infection and were more potent in priming naïve CD4+T cells to produce gamma interferon. In vitro DC infection and T-cell priming studies suggested a delayed CD4+T-cell activation and suppressed Th1/Th2 cell development in C3H mice. The suppressive CD4+T-cell responses seen in C3H mice were associated with a high frequency of Foxp3+T regulatory cells promoted by syngeneicR. conorii-infected BMDCs in the presence of IL-2. These data suggest that rickettsiae can target DCs to stimulate a protective type 1 response in resistant hosts but suppressive adaptive immunity in susceptible hosts.
Regulation of Polysaccharide Utilization Contributes to the Persistence of Group A
Streptococcus
in the Oropharynx
Authors: Shelburne Samuel A. , Okorafor Nnaja , Sitkiewicz Izabela , Sumby Paul , Keith David , Patel Payal , Austin Celest , Graviss Edward A. , Musser James M. 
Published: April 2007

ABSTRACT

Group A
Streptococcus
(GAS) genes that encode proteins putatively involved in polysaccharide utilization show growth phase-dependent expression in human saliva. We sought to determine whether the putative polysaccharide transcriptional regulator MalR influences the expression of such genes and whether MalR helps GAS infect the oropharynx. Analysis of 32 strains of 17 distinct M protein serotypes revealed that MalR is highly conserved across GAS strains.
malR
transcripts were detectable in patients with GAS pharyngitis, and the levels increased significantly during growth in human saliva compared to the levels during growth in glucose-containing or nutrient-rich media. To determine if MalR influenced the expression of polysaccharide utilization genes, we compared the transcript levels of eight genes encoding putative polysaccharide utilization proteins in the parental serotype M1 strain MGAS5005 and its Δ
malR
isogenic mutant derivative. The transcript levels of all eight genes were significantly increased in the Δ
malR
strain compared to the parental strain, especially during growth in human saliva. Following experimental infection, the Δ
malR
strain persistently colonized the oropharynx in significantly fewer mice than the parental strain colonized, and the numbers of Δ
malR
strain CFU recovered were significantly lower than the numbers of the parental strain CFU recovered. These data led us to conclude that MalR influences the expression of genes putatively involved in polysaccharide utilization and that MalR contributes to the persistence of GAS in the oropharynx.
Differential Innate Immune Cell Activation and Proinflammatory Response inAnaplasma phagocytophilumInfection
Authors: Choi Kyoung-Seong , Webb Tonya , Oelke Mathias , Scorpio Diana G. , Dumler J. Stephen 
Published: April 2007

ABSTRACTHuman granulocytic anaplasmosis (HGA) is caused by the obligate intracellular bacteriumAnaplasma phagocytophilum. The critical role of gamma interferon (IFN-γ) for induction of severe inflammatory histopathology, even in the absence of a significant bacterial load, was previously demonstrated in a murine model of HGA. We hypothesized that NK, NKT, and possibly CD8+cytotoxic T cells participate in the development of histopathologic lesions withA. phagocytophiluminfection. Mice were mock infected or infected with low- or high-passageA. phagocytophilumand assayed for hepatic histopathology and splenocyte immunophenotype during the first 21 days after infection. Compared to high-passageA. phagocytophilum-infected mice, low-passageA. phagocytophilum-infected mice had more severe hepatic lesions and increased apoptosis. The hepatic histopathology severity in low-passageA. phagocytophilum-infected mice peaked on day 2 at the time of peak plasma IFN-γ levels and gradually decreased through day 21. Low-passageA. phagocytophilum-infected mice also showed significantly increased levels of lymphocyte NK1.1/FasL expression on days 4 to 7 corresponding to early, severe hepatic inflammation, whereas the levels of NKT cells were substantially lower on day 4, suggesting that there was NKT cell involvement. This result supports the concept that NK1.1+cells, including NK and NKT cells, are major components in the early pathogenesis ofA. phagocytophiluminfection.
CD14 Mediates Cross Talk between Mononuclear Cells and Fibroblasts for Upregulation of Matrix Metalloproteinase 9 byBorrelia burgdorferi
Authors: Zhao Zhihui , Fleming Rhonda , McCloud Bilaal , Klempner Mark S. 
Published: April 2007

ABSTRACTLyme disease is an infection caused by a tick-borne spirochete,Borrelia burgdorferi.Matrix metalloproteinase 9 (MMP-9) was selectively upregulated in the erythema migrans skin lesions of patients with acute Lyme disease. In this study, the mechanism of upregulation of MMP-9 was investigated in vitro and in vivo. The concentrations of MMP-9 and soluble CD14 were markedly elevated in serum from patients with acute Lyme disease and were also upregulated in U937 cells byB. burgdorferiin a time- and concentration-dependent manner. MMP-9 mRNA was expressed at baseline in fibroblasts in the presence or absence ofB. burgdorferi. However, when fibroblasts were incubated with supernatants from U937 cells withB. burgdorferior recombinant CD14, the expression of MMP-9 was significantly increased. This effect was completely abolished by the anti-CD14 antibody. These data suggest that the upregulation of MMP-9 byB. burgdorferiinvolves the CD14 pathway in infiltrating inflammatory cells. Fibroblasts could be recruited to amplify local production of MMP-9 by acquiring CD14 from macrophages.
Interleukin-23 (IL-23)-IL-17 Cytokine Axis in Murine
Pneumocystis carinii
Infection
Authors: Rudner Xiaowen L. , Happel Kyle I. , Young Erana A. , Shellito Judd E. 
Published: April 2007

ABSTRACT

Host defense mechanisms against
Pneumocystis carinii
are not fully understood. Previous work in the murine model has shown that host defense against infection is critically dependent upon host CD4
+
T cells. The recently described Th17 immune response is predominantly a function of effector CD4
+
T cells stimulated by interleukin-23 (IL-23), but whether these cells are required for defense against
P. carinii
infection is unknown. We tested the hypothesis that
P. carinii
stimulates the early release of IL-23, leading to increases in IL-17 production and lung effector CD4
+
T-cell population that mediate clearance of infection. In vitro, stimulation of alveolar macrophages with
P. carinii
induced IL-23, and IL-23p19 mRNA was expressed in lungs of mice infected with this pathogen. To address the role of IL-23 in resistance to
P. carinii
, IL-23p19−/− and wild-type control C57BL/6 mice were infected and their fungal burdens and cytokine/chemokine responses were compared. IL-23p19−/− mice displayed transient but impaired clearance of infection, which was most apparent 2 weeks after inoculation. In confirmatory studies, the administration of either anti-IL-23p19 or anti-IL-17 neutralizing antibody to wild-type mice infected with
P. carinii
also caused increases in fungal burdens. IL-17 and the lymphocyte chemokines IP-10, MIG, MIP-1α, MIP-1β, and RANTES were decreased in the lungs of infected IL-23p19−/− mice in comparison to their levels in the lungs of wild-type mice. In IL-23p19−/− mice infected with
P. carinii
, there were fewer effector CD4
+
T cells in the lung tissue. Collectively, these studies indicate that the IL-23-IL-17 axis participates in host defense against
P. carinii
.