Asymptomatic malaria parasitemia does not induce additional oxidative stress in pregnant women of South East Nigeria

Objective:To determine the relationship between asymptomatic malaria parasitemia and some oxidative stress parameters in pregnant Nigerian women.Methods:This is a cross-sectional study involving 130 normal pregnant women at various trimesters,who were attending antenatal clinic at the University of Nigeria Teaching Hospital(UNTH) and Kenechukwu Specialist Hospital in Enugu.A comparable group(control),made of 30 non pregnant women was also recruited.After a 24 hour dietary recall,serum levels of vitamin A,C and malondialdehyde(MDA) were determined by colorimetric method,while vitamin E was determined by absorptiometric method.Results:There were no statistically significant differences in age,parity,estimated calorie,vitamins A,C and E intake between the pregnant and non pregnant groups(P】0.05).The serum level of the vitamins(umol/L) and MDA(umol/L) in control,1st,2nd and 3rd trimesters respectively were:(l)Vitamin A:1.6±0.36 vs 0.6±0.26 vs 0.62±0.33 vs 0.46±0.21(P【0.0001);(2) Vitamin C:75.65±14.15 vs 62.97±24.4 vs 37.85±15.19 vs 28.94±8.52(P【0.0001);(3) Vitamin E:3.01±1.32 vs 3.45±2.01 vs 9.36±2.75 vs 9.82±2.97(P【0.0001);(4) MDA:1.42±0.02 vs 1.61±0.02 vs 1.79±0.02 vs 2.03±0.05(P【0.0001).However,there were no significant changes in the serum level of the vitamins and MDA between the positive and the negative parasitemia subjects(P】0.05). Conclusions:Asymptomatic malaria parasitemia does not induce additional oxidative stress on pregnant women in Nigeria.The enormity of acute and complicated attack should be further investigated.

一氧化氮对红内期约氏疟原虫感染的影响

目的 :探讨约氏疟原虫感染早期一氧化氮 (nitricoxide ,NO)对红内期疟原虫的影响。方法 :通过ELISA和Griess反应 ,观察疟原虫感染早期宿主体内细胞因子和NO对红内期虫体血症的影响及其效应。结果 :疟原虫感染早期随着以IFN γ分泌增加为主的Th1细胞免疫应答产生的过程 ,NO合成逐渐增加 ,红内期原虫血症受到抑制。一旦解除高水平NO的作用 ,虫体的增殖能力即可迅速得以恢复。结论 :NO通过抑制裂殖子的侵袭力发挥抗红内期原虫感染的保护性免疫效应。

Association of ABO blood group and Plasmodium falciparum malaria in Dore Bafeno Area,Southern Ethiopia

Objective:To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum(P.falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center,Southern Ethiopia.Methods:A total of 269 febrile outpatients who visited Dore Bafeno Health Center,Southern Ethiopia,were examined for malaria and also tested for ABO blood groups in January 2010.The blood specimens were collected by finger pricking,stained with Geimsa,and examined microscopically.Positive cases of the parasitemia were counted.CareStart^(TM) Malaria PflPv Combo was also used to test the blood specimens for malaria.ABO blood groups were determined by agglutination test using ERYCLONE antisera.Data on socio-demographic characteristics and treatment status of the participants were also collected.Chi-square and ANOVA tests were used to assess the difference between frequencies and means,respectively.Results:Out of a total of 269 participants,178(66.2%) febrile patients were found to be infected with Plasmodium parasites,among which 146(54.3%),28(10.4%),and 4(1.5%) belonged to P.falciparum,P.vivax,and mixed infections,respectively.All febrile patients were also tested for ABO blood groups and 51.3%,23.5%,21.9%and 3.3%were found to be blood types of 0,A,B and AB,respectively.Both total malaria infection and P.falciparum infection showed significant association with blood types(P<0.05).The proportion of A or B but not 0 phenotypes was higher(P<0.05) in individuals with P.falciparum as compared with non-infected individuals.The chance of having P.falciparum infection in patients with blood groups A,B and AB was 2.5,2.5 and 3.3times more than individuals showing blood 0 phenotypes,respectively.The mean P.falciparum malaria parasitemia for blood groups A,B,AB,and 0 were 3 744/μ L,1 805/ μ L,5 331/μ L,and1 515/μ L,respectively(P<0.01).Conclusions:The present findings indicate that individuals of blood groups A,B and AB are more susceptible to P.falciparum infection as compared with individuals of blood group O.Nevertheless,further in depth studies are required to clearly establish the role that ABO blood group plays in P.falciparum malaria.

牛巴贝斯虫PCR检测及体外培养试验

本试验通过PCR方法检测出牛巴贝斯虫单一感染的牛全血样本,并探讨了牛巴贝斯虫病患牛全血体外培养方法及培养条件。试验结果表明,PCR检测结果显示检测方法效果较好,单一感染样本的新鲜血液中虫体在含40%牛血清的完全培养液和37℃5、%CO2的条件下能建立起牛巴贝斯虫的体外培养,虫体可以连续培养14 d,传代13次,最高染虫率可以达到12.5%,平均染虫率为4%。

约氏疟原虫自然传播阻断的发生与原虫血症相关性的研究

目的 探讨约氏疟原虫感染早期自然传播阻断的发生机制。方法 观察小鼠红内期原虫血症水平、蚊体内有性阶段的虫体发育状况以及PRBC提取物对脾细胞产生NO的诱导作用。结果 当红细胞感染率达到 15 %～ 2 0 %这一阈值时 ,配子体对蚊的感染力明显减弱或丧失 ;PRBC提取物能够诱导脾细胞合成NO ,其诱导能力具有剂量依赖性。结论 疟原虫自然传播阻断的发生取决于红细胞感染率的高低和中间宿主体内免疫细胞活化后产生的NO水平。

约氏疟原虫初次感染早期的Th1应答对再感染影响的实验研究

目的 探讨约氏疟原虫感染早期Th1反应对再感染的影响。方法 将约氏疟原虫感染早期的部分小鼠用蒿甲醚治愈后 ,对治疗和未治疗而自然自愈的小鼠经腹腔再次感染约氏或伯氏疟原虫 ;应用吉姆萨薄血膜染色法观察并计数两者的红细胞感染率 ;并通过ELISA法检测其脾细胞培养上清中的细胞因子和血清中的抗体水平。结果 自然自愈的小鼠用约氏疟原虫再感染 ,没有虫体血症产生 ,而用伯氏疟原虫感染则产生了低水平的虫体血症 ;蒿甲醚治愈的小鼠对约氏和伯氏疟原虫的再感染均产生了较低的虫体血症 ;初次感染早期脾细胞培养上清中的IFN -γ水平显著升高 ,与此相比 ,约氏疟原虫再感染的小鼠脾细胞可产生更高水平的IFN -γ。结论 疟原虫感染早期Th1反应的建立在抗疟原虫再感染过程中发挥重要的作用 ;

巴贝斯虫病水牛血清钙镁浓度变化与染虫率的关系

自水牛巴贝斯虫病非疫区购买的无任何血液原虫寄生的健康水牛犊２头，人工摘除脾脏后，用从疫区采集的饥饿镰形扇头蜱叮咬感染，观察巴贝斯虫的消长与血清钙、镁浓度的变化，结果发现二者关系密切，其中钙离子浓度与红细胞染虫率呈负相关，镁离子浓度与红细胞染虫率呈正相关，这一发现为进一步研究水牛巴贝斯虫病及在体内外研究巴贝斯虫的生长繁殖均具有重要意义。

Use of buffy coat thick films in detecting malaria parasites in patients with negative conventional thick films

Objective:To determine the frequency of malaria parasite detection from the buffy coal blood films by using capillary tube in falciparum malaria patients with negative conventional thick films.Methods:Thirty six uncomplicated falciparum malaria patients confirmed by conventional thick and thin films were included in the study.The patients were treated with artemisinin combination therapy at Hospital for Tropical Diseases,Bangkok,Thailand for 28 day.Fingerpricks for conventional blood films were conducted every 6 hours until negative parasitemia,then daily fingerpricks for parasite checks were conducted until the patients were discharged from hospital. Blood samples were also concurrently collected in 3 heparinized capillary tubes at the same time of fingerpricks for conventional blood films when the prior parasitemia was negative on thin films and parasitemia was lower than 50 parasites/200 white blood cells by thick film.The first negative conventional thick films were compared with buffy coat thick films for parasite identification. Results:Out of 36 patients with thick films showing negative for asexual forms of parasites, buffy coat films could detect remaining 10 patients(27.8%) with asexual forms of Plasmodium falciparum.Conclusions:The study shows that buffy coat thick films are useful and can detect malarial parasites in 27.8%of patients whose conventional thick films show negative parasitemia.

IL-12在约氏疟原虫感染中作用的初步实验研究

目的:探讨IL-12在约氏疟原虫感染中的作用。方法:尾静脉注射法感染IL-12基因敲除小鼠和B6小鼠约氏疟原虫(17XNL),于感染后的第0、2或4、6天取小鼠尾静脉血,检测血清中的细胞因子;从感染后的第2天起,隔日检测小鼠虫体血症水平。结果:与B6小鼠相比,IL-12基因敲除小鼠在感染后虫体血症水平增长迅速且水平高;清除感染需时较长,但仍能完全清除虫体而存活。在感染后的第0、2、6天血清中无IL-12、IFN-γ,而B6小鼠IL-12I、FN-γ(D4)水平均较高。两者在TNF-α水平上无差别。结论:尽管IL-12对小鼠感染约氏疟原虫后的存活很重要,但无IL-12的小鼠感染约氏疟原虫后仍能存活。

实验感染牛末梢红细胞内卵形巴贝西虫裂殖子的形态学观察

以感染有卵形巴贝西虫的长角血蜱幼虫叮咬感染实验除脾牛,对其末梢红细胞内卵形巴贝西虫的裂殖子的形态及感染率进行了观察。裂殖子可分6个类型,除以往报道的单梨子型、双梨子型、分裂型及退行型之外,还观察到了杆菌型及棒型虫体,随感染率的上升,单梨子型和杆菌型增加,随感染率的下降,棒型及退行型增加。据此认为,虫体的形态与发育阶段有关。根据杆菌型、棒型虫体的出现认为,接种卵形巴贝西虫虫血感染与阳性蜱叮咬感染,其卵形巴贝西虫在牛体内的发育并不相同。

环丙沙星对疟原虫子孢子活力的影响

约氏疟原虫子孢子与新型抗生素环丙沙星不同剂量共同孵育３０ｍｉｎ后腹腔接种昆明株小鼠体内．观察环丙沙星对子孢子活力的影响。环丙沙星分为１、２、４、６、μｇ／ｍｌ５种剂量，另外设双抗（青霉素十链霉素）对照组和ＰＢＳ对照组，每组接种５只小鼠，每鼠０．１ｍｌ，内含１０．５×１０４子孢子，３ｄ后尾静脉取血镜检，结果环丙沙星各试验药物组原虫血症出现的平均时间分别为３．８、３．６、３．８、３．８、３．２ｄ，双抗对照组和ＰＢＳ对照组均为３．８ｄ。结果提示环丙沙星剂量达８μｇ／ｍｌ与子孢子孵育３０ｍｉｎ后仍对子孢子活力无影响。

猴疟B株感染后猴抗体水平与虫血症对蚊媒感染情况的观察

用食蟹猴疟原虫Ｂ株子孢子感染的３只恒河猴，虫现前期分别是８、１０和１１ｄ，虫血症高峰时间在１４～２５ｄ，３只猴均有两个以上高峰，原虫密度波动于０．０３％～５９．６％。初次抗疟原虫抗体反应於感染后１３～１７ｄ测得，抗体高峰在感染后１６～２０ｄ（１：８０～１：３２０）．在虫血症显著期供４６批大劣按蚊血餐，获得好的感染蚊（Ｍ＞５）３０批，平均为１０批，好的感染蚊批的血餐时间分布在抗体滴度高峰期前为２３．３３％（７／３０），高峰期为３３．３３％（１０／３０），高峰期后为４３．３３％（１３／３０）．抗疟原虫抗体在初次测得后，随着红内期原虫密度的增加，抗体滴度短时间内很快上升，达到高峰后持续一段时间再缓慢下降。同时观察到在原虫血症高峰前，常出现一次较好的感染蚊批；抗体滴度高峰之前期间获感染好的蚊批率最低４６．６７％（７／１５），而高峰之后滴度仍维持较高时期获感染好的蚊批率最高１００％（１３／１３）。

食蟹猴疟原虫B株子孢子感染后的虫血症及按蚊血餐感染情况

用食蟹猴疟原虫Ｂ株子孢子感染的６只恒河猴，初发期虫血症自然消长曲线２只猴为双峰形、４只猴为多峰形。虫血症显著期（原虫密度≥２‰）最短者为１３ｄ，最长者为３７ｄ。在虫血症显著期供１１３批（１批／日）蚊（大劣按蚊或斯氏按蚊）血餐，获得感染好的蚊虫（卵囊均数＝５－３２７．７，胃感染率＝６５－１００％）５８批、平均为９．７批。感染好的蚊批分布：双峰形的初峰期为１４．２９％（２／１４），次峰期为８５．７１％（１２／１４）；多峰形的初峰、次１和次２峰期分别为２２．７３％（１０／４４）、４５．５％（２０／４４）和３１．８２％（１４／４４）。结果提示对蚊感染性较强的血餐时间主要分布在次１和次２峰期。

猪尾猴疟原虫广西株慢性感染期对蚊媒感染性的研究

用猪尾猴疟原虫广西株感染猴，Ｍ１猴于接种后第３８０～４８７天期间，每天感染一批蚊媒，７２ｄ获阳性，阳性日可连续１５～３２ｄ，蚊媒感染率最高达６６．６％。Ｍ２猴于接种后第６７５～８４０天，原虫血症复燃６次，每次连续感染蚊媒３ｄ，１７批蚊媒均阳性，其中４次蚊媒感染率达９０％～１００％。原虫血症间隔１～１．５个月有一个回升高峰。结果表明，疟原虫慢性感染在疟疾流行病学上起着重要的传染源作用。

Pharmacodynamic evaluation for antiplasmodial activity of Holarrhena antidysentrica(Kutaja) and Azadirachta indica(Neemb) in Plasmodium berghei infected mice model

Objective:To investigate in-vivo anti-plasmodial activity of aqueous extracts of plants selected based on the symptomology mentioned in Ayurveda.Methods:The aqueous extracts of Holarrhena antidysentrica(H.antidysentrica)(Kutaja) and Azadirachta indica(A.indica)(Neemb) for their antiplasmodial potential in Plasmodium berghei(P.berghei) infected mice was assessed using Peters four day suppressive test.Both the extracts were administered at 2 dose levels,full dose(1 000 mg/d) and minimized dose(200 mg/d).10~6 P.berghei infected RBCs were injected on day ’0’ and treated from day ’0’ till day ’3’ post-infection,Tail blood smears were collected, giemsa stained and analyzed.The mice were observed for survival and parasitemia was assessed till 50%of mice in control survived.Results:It was observed that the percentage of parasitemia increased gradually in all the groups,with maximum in control group(Day 3-35,Day 9-46.98) and minimum in Chloroquine arm(Day 3-14.06.Day 9-19.92).The percentage of parasitemia was compared using Mann-Whitney U test depicting that all test groups exhibited reduction in parasitemia as compared to control(P-value【0.002 for all groups).These groups showed similar percentage of survival as Chloroquine.Conclusions:The present investigation demonstrated the anti-plasmodial effects of H.antidysentrica and A.indica.which are two most commonly used medicinal plants in Ayurved for treatment of fever.

环孢霉素A对鼠伯氏疟原虫红内期的作用

本文通过用皮下给药法（２５ｍｇ／Ｋｇ·ｄ×４）观察了环孢霉素Ａ对经血传感染的小鼠伯氏疟原虫红内期的作用。结果表明，在鼠疟症状期给药，原虫血症急剧下降以至消失，４～６ｄ后，实验鼠全部出现复燃。而在鼠感染的同时给药，直至观察期末的２１ｄ，未见原虫出现，实验鼠仍活动正常，但对近期再感染同种虫源仍处于敏感状态。上述两组实验的对照组鼠，随原虫血症的出现均于感染后６～９ｄ内死亡。

In vivo antiplasmodial and in vitro antioxidant property of stem bark extracts of Haematostaphis barteri

Objective: To evaluate the antimalarial and antioxidant properties of stem bark extracts of Haematostaphis barteri(H. barteri).Methods: The prophylactic activity of the plant was performed by dosing mice with sulfadoxine-pyrimethamine(1.2 mg/kg), aqueous extract(30, 100, 300 mg/kg) and dichloromethane/methanol(D/M)(30, 100, 300 mg/kg) extracts of H. barteri for 3 days. On the 4th day, the mice were inoculated with Plasmodium berghei. The parasite density was estimated for each mouse 72 h post-parasite inoculation. The curative activity of the plant was also performed by inoculating mice with Plasmodium berghei. Three days later, they were treated with artemether-lumefantrine(4 mg/kg), aqueous and D/M extracts of H. barteri stem bark for 5 days. The in vitro antioxidant property of the aqueous extract was determined by using the reducing power, nitric oxide and total antioxidant capacity assays. Results: The aqueous extract exerted significant(P < 0.05) curative and prophylactic antimalarial activities. The D/M extract exhibited significant curative(P < 0.05) but not prophylactic antiplasmodial ef ect. The aqueous extract exhibited in vitro antioxidant property with IC50's of(0.930 ± 0.021) mg/mL,(0.800 ± 0.001) mg/mL and(0.22 ± 0.05) mg/mL in the total antioxidant capacity, reducing power and nitric oxide assays. Histological assessment of the liver of aqueous and D/M treated animals did not reveal any sign of toxicity.Conclusions: H. barteri is not toxic which exerted significant curative antiplasmodial ef ects but the prophylactic property was however fraction dependent. The mechanism of the antiplasmodial activity of H. barteri may partly be mediated by its antioxidant property.

Unsuspected imported malaria in a case of sudden infant death

Here we describe the case of a 4-mo-old female who died suddenly without any apparent cause that was initially mistaken as a case of sudden infant death syndrome. Histologic observation of brain sections revealed blue-black bodies in erythrocytes of the blood vessels, suggestive of specific stages of the hematic schizogonic cycle. Further examinations revealed hemozoin and hemosiderin deposits in the parenchyma of all organs, leading to the diagnosis of malaria by Plasmodium falciparum(P. falciparum). The death occurred in Italy, the native country of the infant, two weeks after a Christmas holiday spent in Pakistan, the parents' birthplace, which has a high malarial endemicity. As this case demonstrates, the diagnosis of malaria should always be considered as a differential diagnosis in subjects, including infants, that die unexpectedly after returning from P. falciparum endemic areas.

Investigation of the Efficacy of Home-Based Oral Chloroquine Treatment among Under-Five Children with Plasmodium falciparum Malaria in Some Parts of Jos, Plateau State, Nigeria

Background: Nigeria is currently a malaria endemic country with an estimated 76% of her population at risk of contracting malaria [1]. According to a study in Nigeria, the first line of action mothers took when their children under 5 years have malaria showed that over 50% of them used non-prescription drugs they have at home or bought from pharmacy stores. And 60% of the most commonly used drugs for malaria treatment were chloroquine [2]. Many recent studies have demonstrated re-emergence of chloroquine-sensitive P. falciparum, suggesting a possible role in future malaria control [3]. Objective: The aim of this study was to investigate the effect of home-based oral chloroquine treatment among children under 5 years with Plasmodium falciparum malaria attending Jos University Teaching Hospital and OLA Hospital in Jos Metropolis. Method: This is a cross-sectional study of 93 malaria and non-malaria children. Malaria diagnosis was carried out using microscopical examination of Leishman’s stained thick and thin blood films, P. falciparum parasitemia was assessed by standard microscopy techniques and complete blood count was done using Beckman Coulter Analyzer. Results: The body temperature on admission was significantly lower (p &#730;C ± 0.07&#730;C) than in the three malaria groups. The mean body temperature of chloroquine treated children with malaria was significantly lower (p Conclusion: The results obtained in this study demonstrate that there was significant positive impact of chloroquine treatment on Plasmodium falciparum parasitemia and degree of anemia in children under 5 years with Plasmodium falciparum in Jos Metropolis.

Hydroethidine-流式细胞术法相对定量分析恶性疟原虫虫血率及其生长周期

本文结合活体荧光染料Hydroethidine（HE）和结合流式细胞术，对实验室培养的恶性疟原虫虫血率及其生长周期进行了相对定量研究和分析，以期寻求一种可替代血涂片镜检法的检测方法。结果表明，染料Hydroethidine工作浓度10μg／ml即可获得与50μg／ml相同的效果；Hydroethidine-流式细胞术法与常规血涂片镜检法具有强相关性；此外，该方法可以进一步分析培养恶性疟原虫中早期（环期、滋养体期）和晚期（裂殖体期）的组成和比例。因此，Hydroethidine．流式细胞术法作为一种客观、准确、快速的相对定量分析方法，在疟原虫研究中具有广泛的应用空间，可以替代血涂片镜检法。