Comparison of floating and sinking encapsulated formulations of the fungus Lagenidium giganteum (Oomycetes: Lagenidiales) for control of Anopheles larvae

Floating calcium alginate capsules containing Lagenidium giganteum and 1% ground cork gave higher levels of control of Anopheles quadrimaculatus larvae in a 100-cm column of water than sinking capsules containing no cork. There was no significant difference between the cork capsules and the sinking capsules in the infection of larvae by the encapsulated fungus after storage (15 degrees C) for 57 days, although infectivity declined during that time from an initial infection rate of 100% to 35% and 40% for the cork and sinking capsules, respectively. Floating capsules containing glass bubbles were less effective than the cork capsules in the 100-cm column of water and had a shorter storage life than either sinking capsules or cork capsules.     

Encapsulation of the mosquito fungal pathogen Lagenidium giganteum (Oomycetes:Lagenidiales) in calcium alginate

The asexual stages (presporangial mycelia) of Lagenidium giganteum cultured on sunflower seed extract were encapsulated in calcium alginate and remained infective to mosquito larvae, Culex quinquefasciatus, after storage at 15 degrees C for up to 75 days. Survival and zoospore release from the encapsulated mycelia persisted for up to 24 days after immersion in water. Encapsulated sexual stages (oospores), held at 23-26 degrees C for up to 35 days or frozen for 8-10 days, were infective to mosquito larvae for up to 48 days after immersion in water and during that time over 50% of the oospores germinated. In outdoor pools, encapsulated mycelia gave 100% control of Cx. quinquefasciatus at 6-7 days after treatment while encapsulated oospores gave 100% control at 11 days posttreatment.     

Efficacy of polymer coating of probiotic beads suspended in pressurized and pasteurized longan juices on the exposure to simulated gastrointestinal environment

Abstract

Alginate-coated Lactobacillus acidophilus LA5 or Lactobacillus casei 01 was recoated with either 0.1–0.5% (w/v) alginate or 0.05–0.15% (w/v) poly-L-lysine (PLL) plus 0.2% (w/v) alginate or 5–15% (w/v) gelatin, after which they were determined for survivability in gastric or bile longan juices. The morphology of encapsulated probiotic cells illustrated that recoated beads with 0.5% alginate showed a more compact surface and a greater protective effect than other recoating materials. The recoated beads with 0.5% alginate and 0.05–0.15% PLL plus 0.2% alginate of both strains showed the highest viability in gastric longan juice. In bile longan juice, only 0.5% alginate showed the best protection for both recoated beads. When considering the storage stability, encapsulated L. acidophilus LA5 exhibited a higher viable count than those of the free cells, whereas L. casei 01 showed equivalent viability of both free and double-coated cells. Based on the impact of pressurization or pasteurization, both processed juices gave rise to equivalent survivability of the probiotic cells during storage.     

饮用矿泉水中绿色沉淀的研究

研究某厂生产的桶装用矿泉水放置１５在后变绿并产生绿色沉淀的原因,方法对生产工艺的各个环节采用分析并做了灭菌,灭藻实验。「结果」矿泉水生产工艺各环节的水样均检出藻类,成品水缸和成品水分别达２２０个／ｍＬ和２４０个／ｍＬ。     

Effect of incorporating prebiotics in coating materials for the microencapsulation of Sacharomyces boulardii

The objective of this study was to microencapsulate Saccharomyces boulardii using the emulsion technique. To microencapsulate the yeast, alginate sodium blended with inulin and mucilage from Opuntiaficus-indica was used as a coating material. The textural properties of the gels formed by the encapsulating materials and the in vitro viability of the yeast strain in the simulated conditions were studied. Textural profile analyses of the gels revealed differences (p < 0.05) in hardness because alginate produced stronger gels, whereas the incorporation of other hydrocolloids with alginate decreased gel strength and resulted in a more uniform, cohesive gel matrix. When alginate was blended with mucilage and inulin, encapsulated yeast presented higher counts and more viable cells, as compared to free yeast following 30 days of storage at 4°C. Encapsulated and free yeast had 76.1% and 63.3%, respectively, of cell viability after 35 days of storage.     

肠内外营养支持与重症胰腺炎时霉菌感染的关系

观察100例接受手术治疗的重症胰腺炎患者中,57例并发霉菌感染(57%),占4个系统100个例次.呼吸系统、消化系统及泌尿系统的各占发病部位的30%左右,血和深静脉导管的霉菌阳性率约为8%.结果提示:当术后PNS持续时间及ENS起始时间均控制在1～7天内时,霉菌感染率最低.PNS持续时间越长,霉菌感染率越高.若在术后8～14天时由PNS向ENS过渡.直至TEN,可望将与长期TPN 禁食有关的霉菌感染率降低.     

The efficacy of oral vaccination of mice with alginate encapsulated outer membrane proteins of Pasteurella haemolytica and One-Shot

The goal of this study was to examine the efficacy of oral delivery of alginate encapsulated outer membrane proteins (OMP) of Pasteurella haemolytica and a commercial One-Shot vaccine in inducing protection in mice against lethal challenge with virulent P. haemolytica. We examined two alginate microsphere formulations and compared them with oral unencapsulated and subcutaneously administered vaccines. Alginate microspheres were made by the emulsion-cross-linking technique. They were examined for size, hydrophobicity, and antigen loading efficiency before they were used in the study. Mice were vaccinated by administering 200 microg of antigens in 200 microl of microspheres suspension orally or subcutaneously. One group of mice received blank microspheres and a second group was given unencapsulated antigen orally. A third and a fourth group received different formulations of alginate encapsulated antigens by oral administration. Three groups received subcutaneous inoculations (alginate encapsulated, non-adjuvanted and unencapsulated antigens, and adjuvanted One-Shot), and one group received water (na?ve group). Mice were vaccinated orally for four consecutive days and challenged with P. haemolytica 5 weeks after the first vaccination. Weekly serum and feces samples were assayed for antigen specific antibodies. The number of dead mice in each group 4 days post challenge was used to compare the efficacy of the various vaccination groups. The mean volume sizes of blank alginate microsphere formulations A, and AA were 15.9, 16 and 9.2 microm, respectively. Hydrophobicity of the microspheres was evaluated by measuring contact angle on a glass slide coated with the microspheres. The contact angles on A and AA were 37.8 and 74.3 degrees, respectively. Antigen concentration in a 1:1 w/w suspension of microspheres in water was 0.9 mg/ml. Rate of death for the blank group was 42.8% whereas for groups vaccinated with antigens encapsulated in A and AA the death rates were 40 and 33.33%, respectively. The death rate in mice vaccinated with unencapsulated antigens was 55.6%. Groups vaccinated by subcutaneous inoculation showed the lowest death rate. These results show that encapsulating OMP and One-Shot in alginate microspheres improves their performance as an oral vaccine.     

酸陛氧化电位水保存后的特性及消毒效果

目的研究酸性氧化电位水在保存过程中理化指标与消毒能力的变化,为其推广应用提供理论依据。方法在常温、封闭、不避光的保存条件下,在保存0、3、7、10、17、24、31、38、45、52、59、66d时,测定酸性氧化电位水的pH值、ORP、有效氯浓度及其作用20min时对枯草杆菌黑色变种芽孢（ATCC 9372）的消毒能力。结果酸性氧化电位水在保存过程中,pH值略有降低,由2.5下降至2.47;变化最大的指标是有效氯浓度,保存到10d,损失率超过50%,保存到66d,已检测不到有效氯浓度;ORP在保存的前45d内,电位降低较缓慢,一直维持在1100mV以上,保存52-66d,电位迅速下降,从1050mV降至612mV。在保存的前7d内,酸性氧化电位水的灭菌率均为100%。保存7d后,灭菌率明显下降,在保存10d后,灭菌率不到90%,在保存45d后,灭菌率仅为51%,可认为已基本失去消毒能力。结论酸性氧化电位水在常温、封闭、不避光的保存条件下,有效期为7-10d,有效氯的衰减可能是导致其在保存过程中消毒能力降低的主要原因。     

Factors affecting storage of mycelial cultures of the mosquito fungal pathogen Lagenidium giganteum (Oomycetes: Lagenidiales)

Sunflower seed extract (SFE) agar cultures (in petri dishes) of Lagenidium giganteum (California isolate) were evaluated for zoospore production and ability to infect mosquito larvae, Culex quinquefasciatus, after periods of storage up to 93 days at 15 degrees C. Rates of decrease in zoospore production and infectivity were related to soluble protein concentration in the SFE-agar media but at all concentrations (0.7-6.0 mg/ml) about 50% of the initial levels were lost after 40-50 days of storage. Water loss from the SFE-agar did not affect zoospore production or infectivity except at extremely high levels (about 98% water loss).     

Serum transferrin receptor in children with respiratory infections

OBJECTIVE: To study the effect of infection on iron status in children suffering from acute, mild or severe respiratory infections and to determine the nature of anemia in infection using serum transferrin receptor (sTfR) levels. DESIGN: Forty-three children aged between 3 and 5 y with no evidence of infection and receiving iron supplements in the preceding 100 days served as controls. Twenty-one children with mild upper respiratory infection and 94 children hospitalized for acute pneumonia constituted the experimental group. Hemoglobin (Hb), sTfR and serum ferritin were estimated in all the children at the time of diagnosis and again on the 15th and 30th days after the infection in those who were available for follow-up. RESULTS: Mean (95% CI) sTfR was 6.08 (5.1-7.1) mg/l in healthy non-anemic children. Upper respiratory infection had no impact on Hb or sTfR but it significantly elevated serum ferritin levels. Eighty-three percent of the children with pneumonia had Hb less than 110 g/l at the time of diagnosis and had elevated mean sTfR, 18.0 (15.7-20.3) mg/l. There was a decline in mean sTfR by the 15th day of infection to 14.3 (11.3-17.4) mg/l with further rise to 22.9 (13.0-31.9) mg/l by 30 days. Serum ferritin was significantly elevated at the time of diagnosis (85.9; 71.1-100.8 micro g/l) as well as at 15 days (89.1; 68-110.1 micro g/l) with a decline by 30 days. CONCLUSIONS: Severe lower respiratory infection exaggerates iron-deficient erythropoiesis by blocking release of iron from the storage pools. sTfR may not be a sensitive and specific tool of assessing true iron status of children exposed to severe infections.     

Boar semen controlled-delivery system: morphological investigation and in vitro fertilization test

A technology for encapsulation of swine semen in barium alginate and protamine alginate has recently been proposed for the controlled release of the spermatozoa, thus reducing the number of instrumental inseminations required. Controlled-release capsules containing swine spermatozoa were prepared by adding saturated BaCl2 solution to ejaculate and dropping the resulting suspension into a sodium alginate solution, leading to the formation of barium alginate capsules. A second type of capsule was obtained by cross-linking the barium alginate with protamine sulfate. Two types of membrane were thus obtained: barium alginate gel and a protamine cross-linked alginate membrane. Morphological (scanning electron microscopy and transmission electron microscopy), functional (motility, membrane integrity and in vitro fertilization test) and technological (capsule structure and weight) approaches were used to characterize the encapsulated spermatozoa and the controlled-delivery system. No differences in terms of morphological and functional characteristics (acrosome integrity and spermatozoa motility) between free and encapsulated semen were found. The technological process did not compromise in vitro fertilization potency of the spermatazoa, although seasonal variability was found. The capsule weight was related to either the pH of the semen or the season. This study represents the starting point for the development of further investigations into the storage and release kinetics of cells from the capsules and for the development of an in vivo fertilization protocol.     

Factors affecting the stability of L-glutamine in solution

The degradation rate of L-glutamine in water, various buffers, and intravenous solutions was assessed over a period of 2 weeks. Measurements were made at various temperatures (22-24 degrees C, and 4 degrees C and -80 degrees C) and pH, and also in the presence and absence of light and oxygen (intravenous solutions only). At 22-24 degrees C, the degradation rate of glutamine was variable depending on the type of solution used (0.23% in water pH 6.5; 0.22% in dextrose/water [15% w/v]; 0.8% in mixed total parenteral nutrition (TPN) solution), and on the pH, molarity and type of buffer used. The degradation rate was essentially unaffected by light and O(2). The degradation rate of L-glutamine in the intravenous solutions was less than 0.15%/day at 4 degrees C, minimal at -20 degrees C (<0.03%/day), and undetectable at -80 degrees C. Glutamine degradation resulted in the equimolar formation of ammonia and no associated formation of glutamate. It is concluded that (a) glutamine degradation in solution is variable due to the effect of physico-chemical factors, and (b) glutamine degradation in TPN solutions is sufficiently slow, especially during storage at 4 degrees C or below, to consider its inclusion in such solutions, for clinical use.     

Storage of cane toad (Bufo marinus) sperm for 6 days at 0 degrees C with subsequent cryopreservation

We investigated the recovery of motility of cane toad (Bufo marinus) sperm after storage for 6 days at 0 degree C (on ice) and after subsequent cryopreservation. Sperm suspensions were prepared from testes macerated in either simplified amphibian Ringer (SAR) or 10% (w/v) sucrose diluents, with 15% or 20% (v/v) glycerol or Me2SO as cryoprotectants, and were stored for 6 days. Alternatively, suspensions were prepared in either SAR or 10% (w/v) sucrose diluent and stored for 6 days, after which some of these suspensions were kept in diluents alone or, alternatively, had 15% or 20% (v/v) glycerol or Me2SO added. All treatments (suspensions) were then cryopreserved. Sperm motility was measured at Day 1 and Day 6 (before and after cryopreservation). A substantial and variable proportion (range 0%-40%) of sperm was immotile in suspensions immediately after preparation from testes macerates. Sperm stored in either SAR or 10% (w/v) sucrose diluent maintained approximately 75% motility for 6 days, but few sperm survived cryopreservation. After storage and cryopreservation, recovery of motility was substantially higher with Me2SO than in glycerol. However, both cryoprotectants exhibited toxicity at high concentrations. Glycerol was more toxic than Me2SO in 10% (w/v) sucrose than in SAR diluent, both before and after cryopreservation. The addition of some cryoprotectants to suspensions before storage gave greater recovery both before and after cryopreservation. After cryopreservation, the highest rate of sperm recovery was in suspensions with 10% (w/v) sucrose and 15% (v/v) Me2SO added prior to storage (mean (+/-SEM) 46 +/- 7% relative to initial; 39 +/- 6% absolute). Sperm were also stored for 6 days at 0 degrees C in suspensions or testes (with suspensions then prepared from testes) and cryopreserved. Sperm maintained higher recovery and membrane integrity both before and after cryopreservation when stored in suspensions rather than in testes.     

Efficacy of encapsulated Lagenidium giganteum (Oomycetes: Lagenidiales) against Culex quinquefasciatus and Aedes aegypti larvae in artificial containers

Presporangial mycelia of Lagenidium giganteum cultured on sunflower seed extract were encapsulated in calcium alginate and added once (July 18) to outdoor (Raleigh, NC) caged tires, wood and concrete containers populated with first instars of Culex quinquefasciatus or Aedes aegypti. First instars were added twice weekly (for 10 wk) to simulate natural oviposition. The fungus persisted for 10 wk and recycled in the mosquito larvae of both species. The overall reductions of Cx. quinquefasciatus and Ae. aegypti immatures were higher in tires (55 and 45%, respectively) and wood (67 and 38%) than in concrete containers (17 and 14%). There were low correlations of the numbers of mosquito immatures with measurements of water quality (chemical oxygen demand, ammonia nitrogen and conductivity) in the containers.     

真菌性鼻窦炎临床及CT特征

目的:探讨真菌性鼻窦炎的临床及CT的特征性表现.方法:分析15例经手术病理证实的真菌性鼻窦炎的CT及临床表现.结果:真菌性鼻窦炎的临床表现有:女性11例(73.3%),病程3年以内13例(86.7%),涕血15例,头痛10例;CT表现有:单侧鼻窦发病14例(93.3%),1例累及双侧,以上颌窦为主,15例均见窦腔内软组织增生影(100%),内可见点状,结节状钙化,2例窦腔增大,骨质破坏.结论:真菌性鼻窦炎的临床表现特征性明显,CT表现有特异性,CT对该病的诊断有重要价值.     

Cold isohaemagglutinins in Plasmodium berghei-infected rats reacting with parasitized reticulocytes

Significant levels of cold IgM and IgG isohaemagglutinins were detected in the serum of rats infected with Plasmodium berghei KSP 11. Peak titres occurred 15 days after initial infection at the time when the parasitaemia was dropping rapidly, or 7 days after a second challenge infection. Infected reticulocytes were much more sensitive to agglutination than uninfected cells, but absorption experiments demonstrated isoantigenicity in the determinants involved. This result indicated that the presence of the parasite resulted in exposure of membrane isoantigens normally masked. Agglutination could be inhibited with fractions with pIs 7.7-7.8 obtained from parasitized reticulocytes. Formaldehyde and glutaraldehyde-fixed infected cells each gave distinct agglutination reactions, different from unfixed cells.     

Protective immunity induced by rPb27 of Paracoccidioides brasiliensis

A cDNA coding for an antigenic protein (rPb27) from the pathogenic fungus Paracoccidioides brasiliensis was cloned and its protective activity was determined against paracoccidioidomycosis (PCM). The cDNA sequence contained an open reading frame (ORF) of 660 base pairs encoding a protein of 219 amino acids with a predicted molecular weight of 25kDa. The deduced amino acid sequence exhibited 100% identity to the 27kDa P. brasiliensis hypothetic protein (access number AA49615). The complete coding cDNA was cloned into a pGEX 4T-2 plasmid and expressed in Escherichia coli as a glutathione-S-transferase-tagged (GST) recombinant protein. Mice immunized with purified rPb27 were able to develop high levels of IgG2b, moderate levels of IgG1 and low levels of IgG2a. At the same time the levels of TGF-beta and IFN-gamma were high while a very low production of IL-10 was verified. Using confocal microscopy with anti-rPb27 mouse serum against P. brasiliensis yeast forms, surface and cytosolic staining pattern were observed. Moreover, immunization of mice with this antigen induced a significant degree of protection in the lungs (93%), liver (93%) and spleen (100%) at 60 days after challenge with infection. Thus, the granulomatous lesions revealed a greater degree of compaction and organization, with few lesions in the lungs and no dissemination of the fungus to other organs. These results showed that a recombinant protein of P. brasiliensis (rPb27) promoted acquired protection against infection with P. brasiliensis yeast forms, suggesting the use of this protein for future development as a prophylactic vaccine for PCM.     

Dietary salt and voluntary ethanol consumption in golden hamsters

Adult male golden hamsters were maintained on powdered Purina chow and tap water, and were permitted continuous access to either a 15% or a 30% ethanol solution (v/v); after an initial 4–5 weeks of ethanol availability, hamsters had stabilized their intakes and were deriving an average of 1.25 and 1.96 g/day of absolute ethanol from the 15% and 30% solutions, respectively. When salt was added to the diet in increasing concentrations ranging from 4% to 10% over a period of 40 days, hamsters reduced chow-derived calories by up to 35%, increased tap water consumption by up to 50%, and increased consumption of ethanol solutions by up to 100%; when unadulterated Purina chow was reinstated, intakes of chow-derived calories, tap water, and ethanol solutions returned to baseline levels. Hamsters that were continuously maintained on unadulterated Purina chow, but with chow-derived calories matched to that of animals on the salt-adulterated diet, significantly increased their ethanol intake, but not their tap water intake; the increase in their ethanol intake was only about half as large as that of hamsters that had salt added to the diet, but the increase persisted even after ad lib feeding was reinstated. The results indicate that the addition of salt to the diet of hamsters produces large increases in ethanol consumption; furthermore, the increased ethanol intake is not simply the result either of a nonselective increase in fluid consumption or of the reduction in food intake that accompanies the addition of salt to the diet. Results are related to the possible role of the renin-angiotensin system in the control of ethanol consumption in the golden hamster.     

Evaluation of polymer-based granular formulations of Bacillus thuringiensis israelensis against larval Aedes aegypti in the laboratory

A strategy to increase residual activity of Bacillus thuringiensis serovar. israelensis (Bti) extract through slow-release formulations and protection from solar radiation was studied. The median lethal concentration (LC50) and 90% lethal concentration (LC90) levels of laboratory-reared early 4th-stage larval Aedes aegypti after exposure to Bti extract were determined. Formulations with 4 polymers and 1 solar protectant were prepared, and their shelf lives were evaluated for year-long storage at 20-35 degrees C and 50-80% relative humidity. Also, the effect of ultraviolet light on unformulated (extract) and formulated Bti larvicidal activity persistence was determined. Laboratory bioassays were conducted with larval Ae. aegypti introduced into treated and control containers at 1, 2, 7, 14, 21, 28, 35, and 42 days after treatment, and larval mortalities were checked 24 h after introduction. Probit analysis of Bti extract showed LC50 and LC90 values of 0.016 and 0.051 mg/liter, respectively. The polymer-based Bti formulations showed no significant loss of insecticidal activity after 8 months of storage. Ultraviolet irradiation reduced activity of unformulated Bti extract after different exposure times, up to 40-46%, whereas Bti formulated with gelatin or acacia gum showed lower variation in larvicidal activity than formulations with sodium alginate and paraffin for protecting the activity of Bti toxin. Residual activity against 4th-stage Ae. aegypti in the laboratory for the formulation containing acacia gum at 10% (w/w) was 80% mortality at 14 days after treatment, whereas the Bti formulation containing gelatin (10%, w/w) caused 65% mortality. In addition, Bti formulations made with paraffin at 5% (w/w) sustained up to 60% mortality for 21 days. Unformulated Bti showed only 2.6% mortality, and a commercial preparation maintained 37% mortality, both at 14 days after treatment.     

白血病化疗中并发侵袭性肺部真菌感染多层CT诊断

目的 探讨白血病化疗中并发肺部侵袭性真菌感染的多层CT影像学表现及诊断价值.方法 对100例白血病患者治疗中并发肺部侵袭性真菌感染的CT影像表现进行分析.病例符合确诊标准11例,符合临床诊断89例.结果 CT表现病灶位于双肺89例,右肺8例,左肺3例.病源菌以白假丝酵母菌者最为常见,共51例,热带假丝酵母菌4例,曲霉菌42例,克柔假丝酵母菌1例,无名假丝酵母菌合并烟霉菌1例,曲霉菌合并白假丝酵母菌1例.CT影像学表现将肺部真菌感染分为5型：弥漫型65例,复合型15例,实变型13例,结节或团块型6例,曲菌球型1例.结论 多层CT在白血病化疗中并发肺部真菌感染的诊断和临床治疗观察中具有重要参考价值.