Inhibitory effect of lactoferrin on in vitro growth of Babesia caballi

Lactoferrin (LF) is an important biologic molecule with many functions, one of which is antimicrobial defense. We evaluated the growth-inhibiting effects of four types of LF (native LF, Fe(+3)-bound [holo] LF, Fe(+3)-free [apo] LF, and LF hydrolyzate) on the in vitro growth of Babesia caballi and B. equi. The growth of B. caballi was significantly suppressed in media containing apo LF, but was not inhibited in media containing native LF, holo LF, or LF hydrolyzate. The growth of B. equi was not inhibited by media containing native LF, holo LF, or apo LF. These data indicate that apo LF had the strongest inhibitory effect on B. caballi. This may have been caused by inactivation or inhibition of a growth factor in the culture medium.     

驽巴贝虫和马泰勒虫双重PCR检测方法的建立

目的建立驽巴贝虫(Babesia caballi)和马泰勒虫(Theileria equi)的双重PCR检测方法。方法根据Gen Bank发表的驽巴贝虫裂殖子m RNA BC48基因保守序列和马泰勒虫核糖体小亚基18 s r RNA基因保守序列,设计、合成2对特异性引物,经优化反应条件,建立双重PCR检测方法,并检测该方法的特异性和敏感性。用该双重PCR法对采集于伊犁地区马疑似病例全血样品进行检测,并与镜检法、常规PCR和荧光PCR的结果进行比较。结果建立的双重PCR法可特异性地扩增驽巴贝虫和马泰勒虫的相应目的条带,分别长约155 bp和280 bp,而对其他种属的双芽巴贝虫(B.bigemina)、环形泰勒虫(T.annulata)、瑟氏泰勒虫(T.sergenti)、刚地弓形虫(Toxoplasma gondii)、犬新孢子虫(Neospora caninum)和伊氏锥虫(Trypanosoma evansi)进行扩增未见相应片段。该方法对驽巴贝虫和马泰勒虫的最低检出浓度分别为4.85×105拷贝/μl和4.85×104拷贝/μl。对采集的24份疑似血样进行双重PCR扩增,驽巴贝虫的阳性率为45.8%(11/24),马泰勒虫的阳性率为75.0%(18/24),镜检法、常规PCR和荧光PCR与双重PCR检测的符合率分别为91.7%(22/24)、95.8%(23/24)和95.8%(23/24)。结论建立了可同时检测驽巴贝虫和马泰勒虫的双重PCR方法。     

Prevalence of Theileria equi and Babesia caballi infection in horses from northern Italy

Babesia caballi and Theileria equi are the causative agents of equine piroplasmosis. In this epidemiological study, 294 horses reared in a rural area of northern Italy were studied. During January 2008-January 2009, blood samples were taken for serology (indirect fluorescent antibody test) and for polymerase chain reaction (PCR). Data on the geographical area, sex, and age were collected for statistical analysis of risk factors associated with infection. A seroprevalence of 8.5% was found: 8.2% of the animals were positive for anti-T. equi antibodies and 0.3% for anti-B. caballi antibodies. No dual infections were observed. Of those horses with positive serology to T. equi, 33% were also positive in PCR, whereas none of the seropositive horses for B. caballi was positive in PCR. No significant correlation between sex or age was found for infection status.     

Inhibitory Effects of Pepstatin A and Mefloquine on the Growth of Babesia Parasites

We evaluated the inhibitory effects of pepstatin A and mefloquine on the in vitro and in vivo growths of Babesia parasites. The in vitro growth of Babesia bovis, B. bigemina, B. caballi, and B. equi was significantly inhibited (P < 0.05) by micromolar concentrations of pepstatin A (50% inhibitory concentrations = 38.5, 36.5, 17.6, and 18.1 μM, respectively) and mefloquine (50% inhibitory concentrations = 59.7, 56.7, 20.7, and 4 μM, respectively). Furthermore, both reagents either alone at a concentration of 5 mg/kg or in combinations (2.5/2.5 and 5/5 mg/kg) for 10 days significantly inhibited the in vivo growth of B. microti in mice. Mefloquine treatment was highly effective and the combination treatments were less effective than other treatments. Therefore, mefloquine may antagonize the actions of pepstatin A against babesiosis and aspartic proteases may play an important role in the asexual growth cycle of Babesia parasites.     

Inhibitory effects of extracellular adenosine triphosphate on growth of esophageal carcinoma cells

AIM: To study the growth inhibitory effects of ATP on TE-13 human squamous esophageal carcinoma cells in vitro. METHODS: MTT assay was used to determine the inhibition of proliferation of ATP or adenosine (ADO) on TE-13 cell line. The morphological changes of TE-13 cells induced by ATP or ADO were observed under fluorescence light microscope by acridine orange (A0)/ethidium bromide (EB) double stained cells. The internucleosomal fragmentation of genomic DNA was detected by agarose gel electrophoresis. The apoptotic rate and cell cycle after treatment with ATP or ADO were determined by flow cytometry. RESULTS: ATP and ADO produced inhibitory effects on TE-13 cells at the concentration between 0.01 and 1.0 mmol/L. The IC50 of TE-13 cells exposed to ATP or ADO for 48 and 72 h was 0.71 or 1.05, and 0.21 or 0.19 mmol/L, respectively. The distribution of cell cycle phase and proliferation index (PI) value of TE-13 cells changed, when being exposed to ATP or ADO at the concentrations of 0.01, 0.1, and 1 mmol/L for 48 h. ATP and ADO inhibited the cell proliferation by changing the distribution of cell cycle phase via either G0/G1 phase (ATP or ADO, 1 mmol/L) or S phase (ATP, 0.1 mmol/L) arrest. Under light microscope, the tumor cells exposed to 0.3 mmol/L ATP or ADO displayed morphological changes of apoptosis. A ladder-like pattern of DNA fragmentation was obtained from TE-13 cells treated with 0.1-1 mmol/L ATP or ADO in agarose gel electrophoresis. ATP and ADO induced apoptosis of TE-13 cells in a dose-dependent manner at the concentration between 0.03 and 1 mmol/L. The maximum apoptotic rate of TE-13 cells exposed to ATP or ADO for 48 h was 16.63% or 16.9%, respectively. CONCLUSION: ATP and ADO inhibit cell proliferation, arrest cell cycle, and induce apoptosis of TE-13 cell line.     

Inhibitory effects of peroxisome poliferator-activated receptor gamma on thyroid carcinoma cell growth

Peroxisome proliferator-activated receptor gamma (PPAR gamma) is a nuclear receptor involved in such cellular processes as adipogenesis, inflammation, atherosclerosis, cell cycle control, apoptosis, and carcinogenesis. PPAR gamma gene mutations have been found in 4 of 55 sporadic colon cancers, and a chimeric PAX8-PPAR gamma 1 gene frequently generates a chromosomal translocation in thyroid follicular carcinomas, implicating PPAR gamma in tumor suppression. We investigated whether PPAR gamma is involved in the growth regulation of normal and tumor thyroid cells. We found no mutations in PPAR gamma exons 3 and 5 in human thyroid carcinoma cell lines and tissues. Moreover, 1 cell line (NPA) of 6 analyzed did not express PPAR gamma. Treatment of NPA with PPAR gamma agonists did not induce any inhibitory effect. Conversely, PPAR gamma agonists and PPAR gamma overexpression led to a drastic reduction of the cell growth rate in PPAR gamma-expressing thyroid carcinoma cells. Restoration of PPAR gamma expression in NPA cells induced cell growth inhibition; PPAR gamma agonists induced further inhibition. Growth inhibition induced by PPAR gamma agonists or by PPAR gamma gene overexpression in thyroid carcinoma cells was associated with increased p27 protein levels and apoptotic cell death. Should these data be confirmed, PPAR gamma could be a novel target for innovative therapy of thyroid carcinoma, particularly anaplastic carcinomas, which represent one of the most aggressive tumors in mankind and are unresponsive to conventional therapy.     

Inhibitory effects of aspirin and indometacin on the growth of Helicobacter pylori in vitro

OBJECTIVE: The interactions between non‐steroidal anti‐inflammatory drugs and Helicobacter pylori have not been sufficiently documented to date. The aim of this study was to investigate the possible effects of aspirin and indometacin on the growth of H. pylori and to determine the effects of aspirin on the susceptibility of H. pylori to some antimicrobials. METHODS: Kinetic studies were performed by inoculating strains of H. pylori in brucella broth with different concentrations of aspirin and indometacin. Growth of bacteria in the broth was assessed spectrophotometrically and by viable colony counts after incubation for 24 and 48 h. Bacterial morphology was determined by Gram stain under light microscopy. The minimal inhibitory concentration (MIC) of aspirin and indometacin was determined by the standard agar dilution method. The MIC of amoxicillin, clarithromycin and metronidazole was measured in the presence and absence of aspirin by the E‐test method. RESULTS: Kinetic studies revealed that aspirin and indometacin inhibited the growth of H. pylori in a dose‐dependent manner. The bactericidal activity of these agents was expressed by cell lysis. Aspirin at 400 µg/mL produced an almost 2‐log decrease in the number of CFU/mL at 48 h. Similar inhibitory effects were obtained when 100 µg/mL indometacin was tested. The MIC at which 90% of H. pylori was inhibited was 512 µg/mL and 128 µg/mL for aspirin and indometacin, respectively. Increased susceptibility of H. pylori to amoxicillin, clarithromycin and metro­nidazole was found in the presence of aspirin. CONCLUSIONS: Aspirin and indometacin could significantly inhibit the growth of H. pylori when incubated in brucella broth in vitro. A subinhibitory concentration of aspirin enhanced the susceptibility of H. pylori to some antimicrobial agents.     

Inhibitory effects of the bone-derived growth factors osteoinductive factor and transforming growth factor-beta on isolated osteoclasts.

Demineralized bone matrix contains a number of growth factors for osteoblast-like cells. Two of these, the novel glycoprotein osteoinductive factor (OIF) and transforming growth factor-beta (TGF beta), act together to cause ectopic bone formation in vivo. Since OIF, like TGF beta, is likely released from bone when the matrix is resorbed, we examined the effects of homogeneous OIF and TGF beta on osteoclast function. Osteoclast function was tested in isolated avian osteoclasts and was measured in terms of tartrate-resistant acid phosphatase (TRAP) activity, oxygen-derived free radical production, and formation of characteristic resorption lacunae on slices of sperm whale dentine. OIF (50-100 ng/ml) inhibited the capacity of these osteoclasts to form lacunae whether assessed by the number of excavations per slice or by the total area resorbed. OIF (10-100 ng/ml) or TGF beta (10-20 ng/ml) caused a decrease in TRAP activity as well as a reduction in oxygen-derived free radical generation detected by nitroblue tetrazolium staining. TGF beta had no effect on the resorption capacity of isolated osteoclasts in concentrations that inhibited TRAP activity and nitroblue tetrazolium staining. These results suggest that growth regulatory factors, such as OIF and TGF beta, released during the resorption of bone may be endogenous inhibitors of continued osteoclastic activity. This cessation of osteoclast activity may be an essential preliminary step to the new bone formation that occurs at resorption sites during bone remodeling.     

Inhibitory effects of melatonin on the growth of pituitary prolactin-secreting tumor in rats

The in vivo effects of melatonin on proliferation and apoptosis of 17-beta-estradiol (E2)-induced pituitary prolactin-secreting tumor (prolactinoma) were investigated in rats kept in 12 L/12 D (lights on: 06:00-18:00 hr). As melatonin was shown to induce apoptosis of breast and liver tumor cells, we examined whether melatonin would induce apoptosis of rat pituitary prolactinoma cells. 0.125, 0.25, 0.50 or 1.0 mg melatonin/day/rat was administrated subcutaneously at 17:30-18:00 hr. The weight of prolactinomas was measured. Apoptosis was evaluated using the TdT-mediated dUTP nick-end labeling method. It was found that treatment with 0.25 and 0.50 mg melatonin for 97 days inhibited prolactinoma cell proliferation and increased prolactinoma cell apoptosis. Furthermore, melatonin induced mRNA expression of Bax and cytochrome c protein expression. Conversely, mRNA expression of Bcl-2, and mitochondrial membrane potential were inhibited by melatonin treatment. These results suggest that melatonin inhibits the proliferation and induces apoptosis of rat pituitary prolactin-secreting tumor via perturbation of mitochondria physiology.     

Molecular detection and characterization of potentially new Babesia and Theileria species/variants in wild felids from Kenya

Piroplasms frequently infect domestic and wild carnivores. At present, there is limited information on the occurrence and molecular identity of these tick-borne parasites in wild felids in Kenya. In 2009, a pair of captive lions (Panthare leo) was diagnosed with suspected babesiosis and mineral deficiency at an animal orphanage on the outskirts of Nairobi, Kenya. Blood smears indicated presences of haemoparasites in the erythrocytes, however, no further investigations were conducted to identify the infecting agent. The animals recovered completely following diet supplementation and treatment with anti-parasite drug. In this report, we extracted and detected parasite DNA from the two lions and seven other asymptomatic feline samples; two leopards (Panthera pardus) and five cheetahs (Acinonyx jubatus). Reverse line blot with probes specific for Babesia spp. of felines indicated the presence of new Babesia species or genotypes in the lions and leopards, and unknown Theileria sp. in the cheetahs. Phylogenetic analyses using partial sequences of 18S ribosomal RNA (18S rRNA) gene showed that the parasite infecting the lions belong to the Babesia canis complex, and the parasite variant detected in the leopards clusters in a clade bearing other Babesia spp. reported in wild felids from Africa. The cheetah isolates falls in the Theileria sensu stricto group. Our findings indicate the occurrence of potentially new species or genotypes of piroplams in all three feline species.     

Inhibitory effects of apigenin on the growth of gastric carcinoma SGC-7901 cells

AIM: To explore the growth inhibition and apoptosis-inducing effect of apigenin on human gastric carcinoma SGC-7901 cells. METHODS: The effects of apigenin on the growth, clone formation and proliferation of human gastric carcinoma SGC-7901 cells were observed by MTT, clone-forming assay, and morphological observation. Fluorescent staining and flow cytometry analysis were used to detect apoptosis of cells. RESULTS: Apigenin obviously inhibited the growth, clone formation and proliferation of SGC-7901 cells in a dosedependent manner. Inhibition of growth was observed on d 1 at the concentration of 80 μmol/L, while after 4 d, the inhibition rate (IR) was 90%. The growth IRs at the concentration of 20, 40, and 80 μmol/L were 38%, 71%, and 99% respectively on the 7~(th) d. After the cells were treated with apigenin for 48 h, the number of clone-forming in control, 20, 40, and 80 μmol/L groups was 217±16.9, 170±11.1 (P<0.05), 98±11.1(P<0.05), and 25±3.5 (P<0.05) respectively. Typical morphological changes of apoptosis was found by fluorescent staining. The cell nuclei had lost its smooth boundaries, chromatin was condensed, and cell nuclei were broken. Flow cytometry detected typical apoptosis peak. After the cells were treated with apigenin for 48 h, the apoptosis rates were 5.76%, 19.17%, and 29.30% respectively in 20, 40, and 80 μmol/L groups. CONCLUSION: Apigenin shows obvious inhibition on the growth and clone formation of SGC-7901 cells by inducing apoptosis.     

阿司匹林和吲哚美辛对幽门螺杆菌生长的抑制作用

目的 探讨体外培养条件下，阿司匹林和吲哚美辛对幽门螺杆菌（Hp)生长的影响，以及阿司匹林存在时，Hp对几种常用抗生素敏感性的影响。方法 Hp接种于含不同浓度阿司匹林或吲哚美辛的布氏肉汤中培养，测定不同培养时间菌液的吸光度，稀释法计数活菌数，革兰染色观察细菌形态，琼脂稀释法测定阿司匹林和吲哚美辛的最低抑菌浓度（MIC），E-检测法检测Hp对甲硝唑，克拉霉素及羟氨苄青霉素的MIC，结果 阿司匹林和吲哚美辛可抑制Hp的生长，这种抑制作用呈剂量依赖性，与培养基pH改变无关，400μg/ml阿司匹林或100μg/ml吲哚美辛体外培养48h可使Hp完全溶解破坏，阿司匹林和吲哚美辛对Hp的体外MIC90分别为512和128μg/ml。阿司匹林存在时，分别使100%，75%及75%的Hp对羟氨苄青霉素，甲硝唑及克拉霉素的MIC降低，提示阿司匹林可使Hp对上述抗生素的敏感性增高。结论 阿司匹林和吲哚美辛可抑制Hp的生长。阿司匹林可提高Hp对甲硝唑，克拉霉素及羟氨苄青霉素的敏感性。     

血管内皮细胞生长因子反义寡核苷酸对小鼠Lewis肺癌生长和转移的抑制作用

目的探讨血管内皮细胞生长因子(VEGF)反义寡核苷酸对小鼠Lewis肺癌生长和转移的抑制作用。方法复制小鼠Lewis肺癌模型24只,随机分为对照组、VEGF反义寡核苷酸(ASODN)组、VEGF错义寡核苷酸(MSODN)组,每组8只,接种肿瘤细胞24h内分别给予生理盐水、VEGF-ASODN、VEGF-MSODN皮下注射,隔日一次,共15次。检测皮下移植瘤的变化和肺转移率,并用免疫组织化学的方法检测肿瘤组织微血管密度(MVD),及用Western blot的方法检测肿瘤组织VEGF蛋白表达。结果ASODN组和MSODN组的抑瘤率分别为47.34%和7.28%,具有显著差异(P<0.01);ASODN组肺转移率为37.5%,低于MSODN组(75.0%)和对照组(87.5%);ASODN组MVD为12.29±2.06,低于MSODN组(17.38±3.24)和对照组(20.14±3.90)(P<0.05);且ASODN组VEGF蛋白表达亦明显减弱。结论VEGF-ASODN可抑制小鼠Lewis肺癌的生长和转移,为肺癌的治疗提供新的方法。     

Inhibitory effects of octreotide on renal and glomerular growth in early experimental diabetes in mice

It was recently discovered that the streptozotocin (STZ)-diabetic mouse model is characterised by GH hypersecretion in contrast to the STZ-diabetic rat, the former thus mimicking the changes in GH in human type 1 diabetes. Inhibition of circulating and renal IGF-I by long-acting somatostatin analogues reduces renal and glomerular growth and urinary albumin excretion in diabetic rats. The aim of the present study was to examine renal and glomerular growth in early experimental diabetes in mice along with changes in the GH/IGF-I axis following treatment with the somatostatin analogue octreotide. Balb/C(a) mice were randomised into non-diabetic controls, placebo-treated and octreotide-treated diabetic (50 microg/day) mice and examined 7 and 14 days after induction of diabetes. There was no effect of octreotide treatment on body weight, glycaemic control or food intake. However, octreotide treatment significantly inhibited renal and glomerular growth by the end of the study period when compared with placebo treatment. In addition, octreotide prevented an increase in kidney IGF-I by day 7. GH hypersecretion was observed in the diabetic groups but octreotide treatment reduced GH levels compared with placebo treatment by day 14. No significant differences in serum or kidney IGF-binding protein-3 levels were observed between placebo- and octreotide-treated diabetic mice. In conclusion, this new diabetic mouse model mimicking human type 1 diabetes is characterised by GH hypersecretion and the somatostatin analogue octreotide is able to prevent renal and glomerular growth, probably mediated through changes in circulating GH and local kidney IGF-I levels.     

奥曲肽对人胃癌SGC-7901裸鼠种植瘤生长的影响

目的观察生长抑素类似物奥曲肽在体内对胃癌生长的影响。方法人胃癌细胞株SGC7901细胞接种于48只裸鼠背部皮下制成荷瘤动物模型。第8天将裸鼠随机分成4组:奥曲肽(Oct组,100μg/kg;s.c.qd);5Fu组(17mg/kg,ip,2次/周);奥曲肽和5Fu联合治疗组(联合治疗组);对照组,每组各12只裸鼠。连续用药6周。末次用药24小时后处死动物,检测肿瘤体积、重量、坏死体积,比较抑瘤率。结果奥曲肽组、5Fu组、联合治疗组、对照组的平均瘤体体积(cm3)分别为2.17±0.78、2.19±0.79、1.36±0.75、3.23±0.74(F=9.317,P=0.0001);平均瘤体重量(g)分别为6.88±2.06、7.22±2.47、4.47±2.28、10.30±2.80(F=5.452,P=0.0001);平均坏死体积(cm3)分别为0.55±0.38、0.52±0.53、1.14±0.83、0.32±0.27(F=13.987,P=0.0001);奥曲肽组、5Fu组、联合治疗组的抑瘤率分别为:33.20%、29.92%、56.60%(χ2=6.461,P=0.04)。结论奥曲肽可以抑制裸鼠胃癌移植瘤的生长。     

Inhibitory effects of interferon on the expression of genes regulated by platelet-derived growth factor.

The G0/G1 to S transition in quiescent BALB/c 3T3 cells stimulated by serum growth factors can be specifically blocked by the administration of interferon (IFN) to the system. In the present communication, we studied whether IFN inhibits the early events in the G0/G1 phase that are initiated by the platelet-derived growth factor (PDGF). The results show that IFN inhibits most of the PDGF-mediated increase of c-myc, ornithine decarboxylase, and beta-actin mRNAs measured 3 hr after stimulation. c-fos mRNA levels are reduced by IFN as early as 20 min after exposure of the quiescent cells to PDGF. The expression of several genes that belong to the competence gene family is, therefore, inhibited by IFN and this could account for the failure of the IFN-treated cells to enter into the S phase when growth factors present in the platelet-poor plasma are added. We also report that the PDGF-mediated increase in the uptake of deoxyglucose is not impaired by IFN, thus suggesting that the early effects of IFN on gene expression do not result from inhibition of binding of PDGF to its cell-surface receptors. Unlike the direct stimulatory effect of PDGF, which is not sensitive to cycloheximide, the inhibitory effect of IFN on c-myc mRNA levels depends in part on protein synthesis. We propose that a putative product of one of the IFN-induced genes could mediate the decrease in expression of the PDGF-regulated gene family.     

Inhibitory effect of captopril on cell degeneration and growth

Since the first administration of the angiotensin-converting enzyme (ACE) inhibitor captopril for the treatment of essential hypertension, it has been recognized that the ACE inhibitor has a positive influence on the cardiovascular system, on both a molecular and a clinical level.Over the past 25 years, the indications for ACE inhibitors have spread into many fields. During this period, interesting effects of ACE inhibitors in noncardiac fields have been reported. The present review outlines two studies regarding the protective effect of captopril on cardiomyopathy and its therapeutic effect on sarcoidosis.     

Inhibitory effects of bisphosphonate on vascular calcification

Recently, it has been hypothesized that vascular calcification is an actively regulated process in which vascular smooth muscle cells (VSMCs) acquire osteoblast-like functions. Bisphosphonates prevent in vitro calcification of VSMCs and probably inhibit phosphate transport by sodium dependent phosphate transporter which plays a key role in VSMCs calcification. The effects of bisphosphonate on VSMCs have important implications for the future management of patients with vascular calcification.