Kidney complications in EMC virus-induced diabetes in conventional DBA/2 male mice

Conventional DBA/2 male mice of about 9 weeks of age were inoculated by intraperitoneally injecting EMC virus M variant (10(4) TCID50/0.1 ml/animal) which is passaged in mice. The mice which tested positive for glycosuria and hyperglycemia were examined histopathologically 2 or 5 months after inoculation. The kidneys were examined for thickening of Bowman's capsule and the mesangial matrix. These changes were more clearly observable 5 months after inoculation than they were 2 months after inoculation.     

黄芪总黄酮对病毒性心肌炎小鼠心律失常与内质网应激因子的影响

目的：研究黄芪总黄酮（TFA）对病毒性心肌炎小鼠心律失常与内质网应激及缝隙连接蛋白作用,明确TFA抗病毒性心肌炎合并心律失常作用机制。方法：36只雄性Balb/c小鼠分为正常对照组、病毒性心肌炎组和TFA组（n=12）,病毒性心肌炎组腹腔内无菌注射含0.1 ml/d 10-950 TCID柯萨奇B3病毒（CVB3）,注射3 d制备Balb/c小鼠病毒性心肌炎模型,TFA组给予CVB3同时尾静脉注射0.1 ml TFA （20 mg/L）,共7 d。实验结束后心电图检测心律失常发生率后处死小鼠,取心脏行HE染色,观察心肌病理改变,Western blot检测各组小鼠心肌细胞葡萄糖调节蛋白78（GRP78）、内质网应激信号通路因子激活转灵因子4（ATF4）及缝隙连接蛋白（Cx43）表达。结果：与正常组比较,病毒性心肌炎组GRP78与ATF4的表达显著升高（P<0.01）,Cx43表达明显下降（P<0.01）;与病毒性心肌炎组比较,TFA组小鼠心肌细胞GRP78与内质网应激信号通路因子ATF4表达明显减少（P<0.01）,Cx43表达明显增多（P<0.01）。结论：TFA抗心律失常作用可能与缓解内质网应激及增加Cx43表达有关。     

Tryptophan as an Auxin Precursor in Cucumber Seedlings

The conversion of tryptophan-(14)C to indoleacetic acid-(14)C in cucumber hypocotyls occurred under both sterile and non-sterile conditions. This conversion was not reduced under sterile conditions. The growth response of cucumber hypocotyl segments to exogenously supplied tryptophan was almost as great under sterile conditions as when contaminating micro-organisms were present. These data are consistent with the hypothesis that tryptophan is a normal precursor of indoleacetic acid in cucumber tissues.The conversions of tryptamine-(14)C and indoleethanol-(14)C to indoleacetic acid-(14)C also occurred under both sterile and non-sterile conditions. Indoleethanol-(14)C was formed from tryptamine-(14)C. Hypocotyl segment growth responses to tryptamine and to indoleethanol were not decreased under sterile conditions.     

Evaluation of the serum-free medium MDSS2 for the production of poliovirus on vero cells in bioreactors

The serum-free medium MDSS2 (Merten et al., 1994), was used for cultivating Vero cells as well as for producing poliovirus (Sabin type 1) in static and in perfused micro-carrier cultures. At slightly different growth rates of 0.0120/h and 0.0106/h, respectively, static cultures in serum-containing (SCM) and serum-free (SFM) medium produced titers of ^106.75 and 10^6.67 TCID50 per 50 μl; signifying a specific productivity of 0.89 and 1.07 TCID50/c. Serum-free bioreactor cultures of Vero cells on DEAE-dextran microcarriers at 6.25 g/l produced cell densities of about 1.5×10⁶c/ml. After infection with virus (multiplicity of infection (MOI) 0.1–0.3) titers of about 6.3×10⁸ TCID50/ml were obtained, signifying an average specific productivity of 7.1 TCID50/c.h. Although these values were 4 and 2 fold, respectively, higher than in classical resum-based production processes (Montagnon et al. Dev. biol. Stand. 1981, 47, 55), a reference culture, for which cell growth was done in SCM and only virus production was done in SFM, produced 2×10⁹ TCID/ml with an average specific virus production rate of 18.9 TCID50/c.h. The differences between the fully serum-free and our reference process were mainly due to physiological differences of cells grown in SCM and SFM and also due to strongly modified consumption kinetics after virus infection leading to limitations of one or several essential medium compounds, like glucose and amino acids. Avoiding these limitations by increasing the residual concentration of glucose, glutamine, histidine, and SH-amino acids, led to specific virus production rates (of about 17.9 TCID59/c.h.) comparable to those found in the reference virus production process. The optimisation of the production of the poliovirus (Sabin 1) will be described with respect to the modification of the medium composition. This revised version was published online in June 2006 with corrections to the Cover Date.     

Use of microcosms to determine the survival of the fish pathogen Tenacibaculum maritimum in seawater

The survival of the fish pathogen Tenacibaculum maritimum in different seawater microcosms was investigated during 160 days. The persistence of culturable cells was greater in sterile than in natural seawater. Standard plate counts showed that T. maritimum survived in sterile seawater for more than 5 months at concentration around 10(3) cfu ml(-1). However, T. maritimum proved to be very labile in non-sterile seawater, rendering culturable cells no longer than 5 days. These results were confirmed when DNA-based methods were applied. Regardless of the microcosms used, epifluorescence microscopy counts remained at about 10(6) cells ml(-1) throughout the experiment, even though we can not distinguish T. maritimum in the case of non-sterile microcosms. Resuscitation assays with addition of fresh medium to non-sterile microcosms did not favour the recovery of T. maritimum on solid media. Although morphological changes from filamentous to spheres were observed after 3 days in the non-sterile microcosms, in the case of the sterile microcosms this change was observed at the sixth day. The biochemical, physiological, serological and genetic characteristics were unaffected in the sterile microcosms. The overall results contribute to a better understanding of the behaviour of T. maritimum in natural seawater and suggest that the aquatic bacterial population play an important role in the survival of this fish pathogen.     

Re-sorption of organic compounds by roots of Zea mays L. and its consequences in the rhizosphere

The exudation of soluble carbon compounds from Zea mays roots was investigated over a 10 day growth period under sterile and non-sterile solution culture conditions. The results showed that plants grown in sterile static solution culture, where C was allowed to accumulate, released 8 times less C than plants grown under culture conditions in which the solutions were replaced daily. The increased C loss from plant cultures in which exudates were removed daily was attributable to, (a) the reduced potential for root re-sorption of previously lost C, and (b), increasing diffusion gradients between the root and the surrounding bathing solution increasing passive leakage of exudates from the roots. In treatments where C was removed daily from the root-bathing solution, 86% of the total C lost was of a soluble low molecular weight nature, whereas, in sterile and non-sterile static cultures, allowing the accumulation of C over 10 days, this was reduced to 67.5 and 48% respectively. The main C fluxes operating in a solution culture system (efflux and influx of C by both roots and microorganisms) were examined using a computer simulation model to describe movement of soluble sugar-C in both sterile and non-sterile conditions. In sterile static cultures where C was allowed to accumulate in solution over a 10 day growth period, 98% of the C exuded was re-absorbed by the plant. Where C was removed daily from the root-bathing solution this was reduced to 86%. The predicted patterns of C accumulation were similar to those found in the experiments. Simulations showed that the pattern of accumulation and final equilibrium concentrations were dependent on the rate of exudation, the spatial characteristics of exudation, solution volume, root growth rate and the presence of a microbial population. Simulations under non-sterile conditions showed that roots can compete with microorganisms for exudates in solution indicating the possible importance of re-sorption in a soil environment. The results clearly indicate that roots are capable of regulating the net amount of C released into a solution culture with the amount of C collected being highly dependent on the experimental conditions employed. The possible implications of soluble C influx on processes operating within the rhizosphere and in experimental systems is discussed.     

Inactivation of bovine herpesvirus-1 and bovine viral diarrhea virus in association with preimplantation bovine embryos using photosensitive agents

Hematoporphyrin (HP), hematoporphyrin derivative (HPD), and thiopyronine (TP) are photosensitive agents (PSA) that have a germicidal effect when they are activated by light: helium neon laser (He Ne ) light (HP, HPD), white light (HP, HPD), and yellow-green light (TP). Experiments were conducted with appropriate controls to determine the effect of photosensitive agents a) for inactivating bovine herpesvirus-1 (BHV-1; titre 10(6) TCID(50) /ml) and bovine viral diarrhea virus (BVDV; titre 10(6) TCID(50) /ml); b) for disinfecting Day-7, zona pellucida-intact (ZP-I) bovine embryos that had been exposed to BHV-1 (titre 10(6) TCID(50) /ml) or BVDV (titre 10(6) TCID(50) /ml); and c) on the in vitro development of embryos. Exposure to HP, HPD and TP followed by light irradiation inactivated BHV-1 and BVDV. Embryos exposed to BHV-I were disinfected by HP or HPD (5 mug/ml) in combination with He Ne light, or by HP or HPD (10 mug/ml) in combination with white light. Embryos exposed to BVDV were disinfected by HPD (5 and 10 mug/ml) followed by He Ne or white light irradiation. Exposure of embryos to light alone or to light and HP or HPD had no detrimental effect on their in vitro development; however, exposure of embryos to TP (5 mug/ml) followed by irradiation caused embryonic degeneration. Exposure of embryos to 5 mug of HPD followed by He Ne light, or 10 mug/ml of HP or HPD, followed by white light, is simple methods of disinfecting them of BHV-I and BVDV.     

Comparative evaluation of sensitivity of RNA-polyacrylamide gel electrophoresis and dot immunobinding assay for detection of bluetongue virus in cell culture

Bluetongue virus serotype 1 (Avikanagar isolate) was grown in BHK-21 cell line and titrated. The titre of the virus in BHK-21 cell line was 10(6) TCID50/ml. RNA-polyacrylamide gel electrophoresis (RNA-PAGE) and dot immunobinding assay (DIA) were performed on 10-fold serial dilutions of the sonicated cell culture material. The results indicated that the minimum limit of detection of the virus by RNA-PAGE and DIA was 10(5) TCID50/ml.     

Comparative pathology in ferrets infected with H1N1 influenza A viruses isolated from different hosts

Virus replication and pulmonary disease pathogenesis in ferrets following intranasal infection with a pandemic influenza virus strain (A/California/4/09 [CA09]), a human seasonal influenza H1N1 virus isolate (A/New Caledonia/20/99 [Ncal99]), a classical swine influenza H1N1 virus isolate (A/Swine/Iowa/15/30 [Sw30]), or an avian H1N1 virus isolate (A/Mallard/MN/A108-2355/08 [Mal08]) were compared. Nasal wash virus titers were similar for Ncal99 and Sw30, with peak virus titers of 10(5.1) 50% tissue culture infectious doses (TCID(50))/ml and 10(5.5) TCID(50)/ml occurring at day 3 postinfection (p.i.), respectively. The mean peak titer for CA09 also occurred at day 3 p.i. but was higher (10(7) TCID(50)/ml). In contrast, the peak virus titers (10(3.6) to 10(4.3) TCID(50)/ml) for Mal08 were delayed, occurring between days 5 and 7 p.i. Disease pathogenesis was characterized by microscopic lesions in the nasal turbinates and lungs of all ferrets; however, Sw30 infection was associated with severe bronchointerstitial pneumonia. The results demonstrate that although CA09 is highly transmissible in the human population and replicates well in the ferret model, it causes modest disease compared to other H1N1 viruses, particularly Sw30 infection.     

Resistance of mice with active and maternally passive immunity against Sendai virus

Resistance of mice with active and maternally passive immunity to Sendai virus infection was investigated. Mice with active immunization were convalescent ones from intranasal infection with 10(3) TCID50 of the virus [CT], ones immunized with 4 weekly intranasal injections of about 4 X 10(3) hemagglutinating units (HAU) of formalin-inactivated virus (FV) [IN], or ones immunized with 4 weekly intraperitoneal injections of about 2 X 10(3) HAU of FV [IP]. The serum neutralizing (NT) antibody titers ranged 1 : 10 to 1 : 20 in CT and IN, and 1 : 20 to 1 : 40 in IP at 4 weeks after initial immunization. NT antibody in the lung lavage was detected only in IP in 3/5. After intranasal challenge infection with 10(6) TCID50 of the virus, little or no gross lung lesion, no virus recovery and no body weight loss were observed throughout experiment, in these 3 immunized groups, whereas, control mice showed lung lesions in 4/5 (7 days), virus recovery in 4/5 at 3 days and in 1/5 at 7 days post-challenge, and body weight loss. In additional histological study, bronchiolar epithelial methaplasia and alveolar septal thickening, which were characteristic findings in non-immunized infected mice, were not observed in mice immunized with 2 biweekly injection of about 250 HA of FV and then challenged. Maternal immunity was investigated in offsprings from convalescent dams infected with 10(3) TCID50 at mating [mCT] and from dams immunized intraperitoneally with 4 X 10(3) HAU of FV at 0, 1 and 2 weeks after mating and, 1 and 2 weeks after parturition [mIP]. Serum NT antibody was not detected in mCT, but the titers ranging 1 : 20 to 1 : 40 were detected in mIP. After intranasal challenge of mCT, mIP and offsprings from non-immune mice with 10(3) TCID50 of the virus, virus recovery on day 3 was 2/4, 1/4 and 3/3, and incidence of total lung lesions on day 7 and 12 was 11/21, 2/13 and 16/16, respectively. Body weight gain was suppressed slightly in the immune groups but markedly in the non-immune control.     

Blood in saliva of HIV seropositive drug abusers: possible implication in AIDS transmission.

We have studied hemoglobin concentration in saliva of anti-HIV positive and anti-HIV negative intravenous drug abusers (IVDA) and normal controls and the relationship between hemoglobin concentration in saliva and number of CD4+ cells and clinical status of AIDS in anti-HIV positive IVDA. 120 anti-HIV positive IVDA, 112 anti-HIV negative IVDA and 116 normal healthy subjects not belonging to any risk group for HIV infection completed the study. Saliva was collected at awakening before brushing teeth and the concentration of hemoglobin was determined. Hemoglobin concentration in saliva in basal conditions is higher in anti-HIV positive IVDA with respect to anti-HIV negative IVDA (p less than 0.05) and controls (p less than 0.01). In anti-HIV positive IVDA hemoglobin concentration in saliva is higher in subjects with CD4+ cells less than 200/10(6) l with respect to subjects with CD4+ greater than 200/10(6) l (p less than 0.05) and in subjects with ARC/AIDS with respect to subjects with PGL or who are asymptomatic (p less than 0.01). Subjects with ARC/AIDS have a mean concentration of hemoglobin of 19 micrograms/0.1 ml saliva (range 0-153) which corresponds to 1.3 microliters of blood/ml saliva. If 10 ml of saliva are exchanged during kissing an average of 13 microliters of blood are transferred (110 microliters of whole blood at extreme range). Blood of symptomatic patients has an HIV titer of 7 TCID/microliters which for 10 ml saliva containing an average of 1.3 microliters blood/ml saliva corresponds to an average of 90 TCID (770 TCID at the extreme range).(ABSTRACT TRUNCATED AT 250 WORDS)     

Adaptation to the cell line PLC/PRF/5 of hepatitis A virus released in the cell culture medium

The propagation of hepatitis A virus (HAV), CF53 strain, released without any cytopathic effect into the PLC/PRF/5 cells supernatant, was studied in the course of six serial passages (6th to 11th). The decrease (from 5 to 1 week) of incubation time required to detect HAV, by RIA, in culture supernatant, the increase in Hepatitis A antigen (from 777 to 10,038 c.p.m./50 microliter) and infectivity titre (from 10(3.0) TCID 50/ml to 10(4.5) TCID 50/ml) were consistent with the adaptation of this virus to the cell line PLC/PRF/5.     

Effect of bovine herpesvirus-1 or bovine viral diarrhea virus on development of in vitro-produced bovine embryos.

In previous experiments, zona pellucida (ZP)-intact in vitro-produced (IVP) embryos incubated for 1 hr with 10(6.3) TCID(50)/ml bovine herpes virus-1 (BHV-1), 10(5.3) TCID(50)/ml cytopathic (CP) bovine viral diarrhea virus (BVDV) or 10(5.3) TCID(50)/ml noncytopathic (NCP) BVDV showed no signs of virus replication or embryonic degeneration. The aims of the present study were to investigate whether a prolonged presence (24 hr or 8 days) of 10(6.3) TCID(50)/ml BHV-1 or 10(5.3) TCID(50)/ml BVDV in an in vitro embryo production system affected the rate of cleavage and embryonic development of ZP-intact embryos, and to point out eventual causes of adverse effects. When virus was present in each step of an IVP system, significantly lower rates of cleavage and blastocyst formation of virus-exposed embryos were observed, in comparison with control embryos (P < 0.01). When embryos were only exposed to virus during the in vitro fertilization (IVF), the rates of cleavage and blastocyst formation were significantly affected. The introduction of BHV-1 or BVDV during in vitro maturation (IVM) or in vitro culture (IVC) resulted only in significantly lower rates of blastocyst (P < 0.01). In all experiments, virus replication was not detected in the embryonic cells. On the other hand, virus replication was clearly demonstrated in oviductal cells in the co-culture system, resulting in a degeneration of these cells. In an additional experiment, synthetic oviduct fluid (SOF) without somatic cells was used as an alternative culture system. Even when SOF-embryos were exposed to 10(6.3) TCID(50)/ml BHV-1 or 10(5.3) TCID(50)/ml CP, and NCP BVDV, the rates of blastocyst formation of the BHV-1-, CP-, and NCP BVDV-exposed embryos were not different from the unexposed control embryos, 23%, 24%, and 24%, respectively, vs. 27%. Taken together, it can be concluded that the virus-induced adverse effects on embryonic development in conventional co-cultures were due to changes in the embryonic environment caused by infection of oviductal cells.     

Pathogenesis of human metapneumovirus lung infection in BALB/c mice and cotton rats

Human metapneumovirus (hMPV) is a newly described member of the Paramyxoviridae family causing acute respiratory tract infections, especially in young children. We studied the pathogenesis of this viral infection in two experimental small animal models (BALB/c mice and cotton rats). Significant viral replication in the lungs of both animals was found following an intranasal challenge of 10(8) 50% tissue culture infectious doses (TCID50) and persisted for <2 and <3 weeks in the case of cotton rats and mice, respectively. Peak viral loads were found on day 5 postinfection in both mice (mean of 1.92 x 10(7) TCID50/g lung) and cotton rats (mean of 1.03 x 10(5) TCID50/g). Clinical symptoms consisting of breathing difficulties, ruffled fur, and weight loss were noted in mice only around the time of peak viral replication. Most significant pulmonary inflammatory changes and peak expression of macrophage inflammatory protein 1alpha, gamma interferon, and RANTES occurred at the time of maximal viral replication (day 5) in both models. Cellular infiltration occurred predominantly around and within alveoli and persisted for at least 21 days in mice, whereas it was more limited in time with more peribronchiolitis in cotton rats. Both animal models would be of great value in evaluating different therapeutic agents, as well as vaccine candidates against hMPV.     

大黄在体内抗柯萨奇病毒B3的实验研究

柯萨奇病毒 (Ｃｏｘｓａｃｋｉｅｖｉｒｕｓ ,ＣＶ)属小核糖核酸病毒科肠道病毒属 ,根据其对乳鼠的致病能力不同分为Ａ、Ｂ两组 ,Ａ组病毒能够引起乳鼠广泛性肌炎及坏死 ,Ｂ组病毒可致局灶性肌炎。研究表明 ,ＣＶＢ是病毒性心肌炎的主要病因[1,2 ] 。为寻找一种有效的抗ＣＶＢ3 治疗药物 ,笔者通过体外实验发现大黄注射液有抗柯萨奇病毒作用[3] ,并根据中药大黄五脏皆治的理论 ,本研究进一步利用ＣＶＢ3 病毒性心肌炎小鼠模型观察了该药的抗病毒作用。现报告如下 :1　材料与方法1.1　细胞Ｈｅｐ 2细胞由武汉大学典型培养物保藏中心提供。细…     

Adiponectin gene therapy of streptozotocin-induced diabetic mice using hydrodynamic injection

BACKGROUND: Adiponectin (Adipo), an adipocyte hormone involved in the regulation of glucose and lipid metabolism, has already been identified as a potential therapeutic target for the treatment of diabetes. However, successful delivery of Adipo to the receptors is difficult due to their peptide characteristics. Receptors for Adipo are abundantly expressed in the liver and skeletal muscle. METHODS: Uptake of 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG) in hepatoblastoma HepG2 cells expressing Adipo was examined. Adipo-expressing plasmid DNA (10-50 microg) in saline solution (0.1 ml/g body weight) was rapidly injected into the tail vein of 4-week-old diabetic mice after 4-6 weeks of treatment with streptozotocin (STZ). Uptake of glucose in diabetic mice also was measured using a planar positron imaging system featuring 18-fluorodeoxyglucose. RESULTS: HepG2 cells expressing Adipo exhibited significantly increased 2-NBDG uptake compared with cells transfected with control plasmid even in the absence of insulin. STZ-induced diabetic mice showed decreased serum Adipo levels compared with non-diabetic mice. A single hydrodynamic injection of 10-50 microg Adipo-expressing plasmid DNA into diabetic mice led to approximately 10-15-fold elevation in serum Adipo levels, and resulted in decreased serum levels of glucose and triglyceride. As well as exhibiting higher levels of Adipo expression, diabetic mice also had higher hepatic glucose uptake than similar mice injected with control plasmid. CONCLUSIONS: We report that STZ-induced diabetic mice exhibited decreased Adipo levels and hyperglycemia which may be alleviated by hydrodynamic injection of the Adipo gene. This type of gene delivery system to the liver offers a different approach in developing novel treatments for type 1 and 2 diabetes.     

Microbial immobilization of cadmium released from CdO in the soil

The effect of microorganisms on the fate of Cd introduced into the soil as cadmium oxide (CdO) was investigated. Cadmium oxide (875 µg Cd per gram of soil) was added to -irradiated (sterile) and non-sterile soils. The soils were incubated for 90 days at 18 °C under aerobic conditions with moisture kept at 60% of water-holding capacity. Half of the samples in each treatment were supplemented with starch (0.5%, w/w) in order to stimulate microbial growth in the non-sterile soil. After various time intervals (7- or 10-day), soil samples from each treatment were extracted with deionized distilled water (ratio 1:40) or 0.25 M CaCl₂ (ratio 1:5). The results indicated that during the incubation period the amount of Cd extracted from the non-sterile soil with either solvent was markedly lower than that extracted from the -irradiated sterile control. The addition of starch to the non-sterile soil reduced the concentration of Cd in the 0.25 M CaCl₂ extracts without affecting the Cd-content in the water extracts. Short-term experiments in which Cd was added to the soil as a solution of Cd(NO₃)₂ indicated that irradiation did not affect the sorption of Cd to the soil. The addition of bacterial mass (1 mg of dry weight g^–1 soil) decreased the amount of Cd extracted with water as well as that extracted with 0.25 M CaCl₂. Under sterile conditions the solubility of CdO in soil extracts was higher than in the other extractants. The addition of glucose (0.5%, w/w) or a glucose/starch mixture (0.5%, w/w of each) to the sterile soil increased the amount of extractable Cd after a short incubation (18 h at 18 °C). The obtained results suggest that primarily physicochemical reactions are involved in dissolving CdO in the soil but that microbial activity may be responsible for the immobilization of the released metal.     

Impact of chemical composition of legume residues and initial soil pH on pH change of a soil after residue incorporation

Reports on the effect of organic matter addition on soil pH have been contradictory. This study examined the effect of applying legume residues differing in concentrations of N (4.3-45.5 mg g^-1) and excess cations/organic anions (0.22–1.56 mmol g^-1) on pH change of five soils differing in initial pH (3.60–5.58 in 0.01 M CaCl₂) under sterile and non-sterile conditions. Addition of the legume residues at a level of 1% soil weight increased the pH of all soils by up to 2 units after incubation for 35 and 100 d under non-sterile conditions. Exceptions were the Lancelin (initial pH 5.06) and Kellerberin (pH 5.58) soils with addition of clover roots (excess cations 22 cmol/kg) for 100 d where soil pH decreased by 0.13–0.15 units as compared to the control. The amounts of alkalinity produced in soil correlated positively with concentrations of excess cations and total nitrogen of the added legume residues, and negatively with the initial pH of the soil. When soil was fumigated with chloroform during incubation, similar trends of soil pH changes and alkalinity production, due to legume residues addition, were displayed but the effects of the residue on alkalinity production in the Wodjil and Lancelin soils were much less than under non-sterile conditions. Direct shaking of soil with the residues under sterile conditions increased the amount of alkalinity in the soils with initial pH of 3.60–4.54, but not in the soils with initial pH of 5.06 and 5.58. The maximal alkalinity production was less than one third of that produced in the soil after 100 d of incubation under non-sterile conditions. The results suggest that the direction and the magnitude of pH change depend largely on the concentration of organic anions in the residues, initial soil pH and the degree of residue decomposition. The incorporation of crop residues, especially those with high concentrations of excess cations, is recommended in minimizing soil acidification in farming systems. This revised version was published online in June 2006 with corrections to the Cover Date.     

大黄在体内抗柯萨奇病毒B3的实验研究

In order to search a effective therapy for viral myocarditis, anti vial activity of Rheum officinale on Coxsackieivirus B3 (CVB3) was evalu ated in BALB/C mice. After being determined optium scheme with orthogonal design , mice infected with CVB3 were treated with Rheum officinale, ribavirin an d 0.9% NaCl. The survival rates of the mice were 35%,5% and 5%;Median survival time were 23,11 and 10.5 days;Infectious viral titers were 10-3.2 ,10-4.7 and 10-4.7 TCID50/0.1 mL repectively, The lesion s of cardiac tissues lightened in mice treated with Rheum offinicale. These results showed that Rheum officinale was effective in treatment of CVB3 in fected mice. The study provided scientific basis for further research and widen antiviral spectrum of Rheum officinale.