抗胃酸分泌物对胃内菌群的影响

收集４０例内镜确诊为胃十二指汤溃疡病人,随机分成两组,分别予泰胃美、奥美拉唑口服;干服药后分别行胃检查,并抽吸胃液行需氧菌、厌氧菌及真菌培养。结果示：胃液细菌量及硝酸盐还原菌量与胃液ＰＨ值呈正相关。     

老年人萎缩性胃炎和胃癌与胃液pH及微生态环境改变的关系探讨

本实验研究了老年人萎缩性胃炎和胃癌患者的胃液ｐＨ值及胃内部分菌群数量与正常人胃液ｐＨ值及菌群数量的比较,从１５例萎缩性胃炎患者和１５例胃癌患者的胃液中发现ｐＨ值增高,随之肠杆菌、肠球菌、拟杆菌数量也明显高于正常人,而一些胃内的生理菌少于正常人,由此证明胃内微环境的改变与胃癌的发病率有关系     

超微戊己丸对小鼠胃内微生物的动态影响研究

目的探讨超微戊己丸对胃内微生物的影响及确定超微戊己丸的最佳超微剂量。方法将动物分为正常组、戊己丸传统组、超微全量、1／2量、1／4量、1／8量组,分别灌胃给药,每隔2d取各组小鼠胃内容物做微生物数量分析。结果戊己丸对胃内乳酸菌影响不大（P〉0．05）;戊己丸对胃内细菌有一定的抑制作用,其中超微全量、1／2量、1／4量组在5、7和9d细菌数显著低于正常组（P〈0．05）;戊己丸对大肠埃希菌具有抑制作用,超微全量、1／2量组、1／4量组大肠埃希菌数相对于正常组显著降低（P〈0．05）。结论超微戊己丸能够明显抑制胃内条件致病菌的生长,重新平衡胃内微生态,达到“驱邪”的目的。在无感染状态下,超微戊己丸1／4剂量对胃微生态系统能达到超微全量的调控效果。     

木瓜三萜对吲哚美辛致胃黏膜损伤小鼠胃酸分泌及胃黏膜屏障的影响

观察木瓜三萜对吲哚美辛致胃黏膜损伤小鼠胃酸分泌及胃黏膜屏障的影响,在此基础上探讨其可能的机制。实验时,将小鼠随机分为正常组、模型组、木瓜三萜(50、100mg/kg)和奥美拉唑(20mg/kg)组。将给药组灌胃给予相应的药物,正常组和模型组灌胃给予0.5%羧甲基纤维素钠溶液,给药6小时后,除正常组外,灌胃给予20mg/kg的吲哚美辛,每天一次,连续7天。末次给药次日,小鼠用水合氯醛麻醉后,固定,剪开腹腔,进行胃黏膜血流量的测定,然后取胃检测胃液量、胃液酸度和胃结合黏液量;检测胃黏膜中表皮生长因子基因(EGF)和三叶因子1基因(TFF1)的mRNA和蛋白表达。研究发现:吲哚美辛致胃黏膜损伤模型组小鼠胃液分泌量,胃液酸度、胃黏膜血流量、胃结合黏液量及胃黏膜组织中EGF和TFF1的mRNA和蛋白表达明显降低,与正常组比较均具有统计学差异(P<0.01);用木瓜三萜预处理后,上述异常的变化均得到了有效逆转,与模型组比较具有显著性差异(P<0.05,P<0.01)。实验结果表明木瓜三萜(50、100mg/kg)对吲哚美辛致小鼠胃黏膜损伤具有较好的保护作用,通过上调EGF和TFF1的表达水平,增加胃液分泌量、胃液酸度、胃黏膜血流量、胃结合黏液量,恢复胃黏膜防御屏障的功能可能是其治疗吲哚美辛致胃黏膜损伤的机制之一。     

双歧杆菌对新生儿呼吸机相关肺炎肠源性致病菌的影响

目的探讨给机械通气新生儿补充双歧杆菌是否能有效控制呼吸机相关性肺炎（VAP）肠源性感染。方法将机械通气新生儿随机分两组,观察组鼻饲双歧杆菌,对照组不干预,观察两组发生VAP的情况、胃液pH、胃细菌定植、病原菌分布、病原菌与胃定植细菌的同源性等。结果观察组VAP发生率显著低于对照组,分别为13．16％和46．51％（P〈0．01）。机械通气第3天、第5天、第7天观察组pH≤3的比率均高与对照组（P〈0．01）;第5天及第7天观察组胃细菌定植比率均低于对照组（P〈0．01）;观察组病原菌与胃定植菌同源比率低于对照组（P〈0．01）,均具统计学意义。结论双歧杆菌可降低胃液pH,减少胃内细菌定值,抑制肠道细菌经胃-咽-下呼吸道的移位而减少新生儿肠源性VAP。     

老年人胃内菌群研究

目的研究人体胃内菌群,探讨老年与非老年人胃内菌群的差异。方法选择67例无严重胃肠道疾病的患者为研究对象。其中男性50例、女性17例。年龄≥60岁53例,〈60岁14例。胃镜下取胃组织及胃液,测胃液pH,并做胃组织需氧、厌氧细菌培养及真菌培养,计数胃组织细菌培养数量。16SrRNA法鉴定胃组织细菌种类。真菌的鉴定按微生物科常规菌种方法鉴定。结果老年人中胃内需氧细菌培养阳性为23例（48.93%）,12例（25.53%）胃内需氧菌培养〉1×10^5CFU/g;厌氧细菌培养阳性为22例（46.81%）,12例（25.53%）胃内厌氧菌培养〉1×10^5CFU/g。非老年人中需氧细菌培养阳性为4例（28.57%）,1例（7.14%）胃内需氧菌培养〉1×10^5CFU/g;厌氧细菌培养阳性为4例（28.57%）,1例（7.14%）胃内厌氧菌培养〉1×10^5CFU/g。但老年人与非老年人比较,细菌培养阳性率及细菌培养〉1×10^5CFU/g的比率差异无显著性。仅1例老年人胃组织分离出真菌,为白色念珠菌。胃内共分离出细菌69株,其中革兰阳性球菌31株（44.93%）,革兰阳性杆菌12株（17.39%）,革兰阴性球菌11株（15.94%）,革兰阴性杆菌15株（21.74%）。需氧菌13株（18.84%）,需氧兼性厌氧菌54株（78.26%）,专性厌氧菌2株（2.90%）。老年人胃内常见的细菌是：链球菌、大肠埃希菌、奈瑟菌;非老年人胃内常见的细菌是：链球菌和大肠埃希菌。多为口咽部和胃肠道常见菌群,部分为条件致病菌。结论约46%～48%的老年人胃内细菌培养阳性,约25%的老年人有胃内细菌过度生长（〉1×10^5CFU/g）。约28%的非老年人胃内细菌培养阳性,约7%的非老年人有胃内细菌过度生长。老年人胃内菌群分布与非老年人相似,为口咽部和胃肠道常见菌群,部分为条件致病菌。     

单核细胞增多性李斯特菌在体外模拟消化道环境中的抗性

[目的]通过测定存活率及细胞内pH(pHi)变化,分析单核细胞增多性李斯特菌(单增李斯特菌)在体外模拟消化道中的抗性.[方法]模拟唾液、胃液和小肠液根据其主要组成成分配制,按试验设计顺次加入后获得模拟的消化道各段混合液(包括相应的pH及其可能的范围).平板计数法测定单增李斯特菌在模拟消化液中的存活率,并用荧光比例成像显微镜(fluorescence ratio imaging microscopy,FRIM)测定细菌的pHi.[结果]单增李斯特菌在唾液中存活率＞90％;经pH≤3.0的胃液处理后,其在胃液和胃-肠混合液中的存活率低于0.05％;提高胃液pH至3.5,细菌存活率开始上升;在胃液pH4.0时,两株单增李斯特菌在模拟胃肠液中存活率显著提高(11.2％-85.9％).FRIM研究表明,单增李斯特菌在模拟唾液中的pHi与对照组相近.经过pH为3.5和4.0的胃液和胃-肠混合液处理后,pHi值仍维持在较高水平(＞7.75).[结论]单增李斯特菌在经过pH≥3.5胃液后,能够维持菌体细胞内的pH稳态,且存活率较高,表明其细胞膜仍保持完整.     

金葡菌及其L型感染荷瘤小鼠肿瘤内及非荷瘤小鼠肝脏内MDA和SOD的研究

用Ｐｙｒｏｇａｌｏｌ－ＮＢＴ等方法测定并分析荷瘤感染组,荷瘤非感染组及金葡菌及其Ｌ型感染组小鼠肿瘤或肝脏内超氧化歧酶（ＳＯＤ）和丙二醛（ＭＤＡ）含量对小鼠生存的影响。结果发现荷瘤伴感染组小鼠的平均存活天数明显短于荷瘤非感染组及正常对照组,Ｐ＜０．０５。,共中１６．７％荷瘤伴感染组小鼠同时伴有自发性肿瘤。金葡菌及其Ｌ型感染组２３．３％引起自发性肿瘤。金葡菌及其Ｌ型感染组及荷瘤伴感染组小鼠肿瘤和肝脏内ＭＤＡ含量明显高于荷瘤非感染组,Ｐ＜０．０５～０．０１。９８．７％荷瘤组小鼠肿瘤内ＳＯＤ含量极少或为零。金葡菌及其Ｌ型感染组与正常对照组小鼠肝内ＳＯＤ有明显差异,Ｐ＜０．０５。提示感染可能使小鼠体内ＳＯＤ量减少,ＭＤＡ量升高是引起小鼠发性肿瘤发生的重要原因之一。     

绍兴家鸭腺胃生长抑素免疫反应细胞的年龄变化

用ＡＢＣ免疫组织化学方法,标记０—２２周龄期绍鸭腺胃生长抑素免疫反应细胞（Ｄ细胞）。观察细胞形态、分布,计数腺胃内Ｄ细胞数目及其与体重、胃重的关系。结果表明;１．腺胃内Ｄ细胞形态多为圆形、卵圆形,单个散在分布。主要位于腺胃腺叶的内侧区和中间区。２．腺胃内Ｄ细胞数随周龄增加而渐增多,至１８周龄达顶峰,２２周龄开始减少。此变化规律用二次曲线方程Ｙ＝０．１０２＋４．４５２Ｘ—０．１４２Ｘ～２反映, Ｒ～２＝０．９５（Ｐ＜０．０１）。３．Ｄ细胞数与体重在６周龄后开始出现负相关,至１８周龄达显著负相关,ｒ＝－０．８２９（Ｐ＜０．０５）。Ｄ细胞数与胃重在各周龄期均未见明显相关。     

不同鼠龄大鼠胃酸、胃内细菌变化与感染的关系

目的 研究不同鼠龄大鼠胃内pH的变化与胃及肺部细菌数量变化的关系,以及细菌的生长是否能引起大鼠胃肠道及肺部的炎症反应.方法 Wister大鼠30只,分为非老龄对照组、非老龄奥美拉唑组和老龄组.2周后测大鼠胃内pH,取大鼠胃及肺组织做细菌培养,观察大鼠是否有腹泻,并做胃及肺组织病理切片.结果 与非老龄对照组大鼠相比,老龄组胃内pH、胃及肺部细菌数量差异均无显著性;非老龄奥美拉唑组胃内pH、胃及肺部细菌数量差异均有显著性.3组大鼠实验期间未发现明显的腹泻,观察3组大鼠的病理切片,胃组织无明显炎细胞浸润.非老龄对照组与老龄组相似,肺组织均有轻度淋巴细胞浸润,非老龄奥美拉唑组中30%的大鼠肺部炎症稍重.结论 随胃内pH升高,大鼠胃及肺部细菌数量增加,但未发生明显的胃肠道炎症,组织学上肺部炎症反应有所增加.随鼠龄的增加,大鼠胃及肺部细菌数量增加不明显,未出现明显的胃肠道炎症和肺部炎症.     

Theoretical studies on the necessary number of components in mixtures

Summary Theoretical studies on the necessary numbers of components in mixtures (for example multiclonal varieties or mixtures of lines) have been performed according to risk considerations — using the binomial distribution and the Polya-distribution. The risk r of a mixture has been defined as the probability of catastrophic losses (catastrophe = decrease of productivity of q% or more by susceptibilities of the components). Using 1) the binomial distribution and 2) its generalization, the Polya-distribution, and several simplifying assumptions, the risks r = r (x, a, q, n) have been calculated numerically (n = number of components in the mixture, a = parameter for the intensity of contagion and dispersion of susceptibilities (for example: diseases and epidemics), x = probability of susceptibility). The Polya-model reduces to the binomial case if a = 0. The main results are: 1. For each number n of components the risk r decreases markedly with decreasing x (for each q and for each a). 2. For x < = q the risk r decreases with an increasing number n of components (for each a). 3. For each number n of components and x and q with x < q the risk r increases with increasing a. 4. For given q, x and a the functions r = r(n) are asymptotic for larger numbers n of components with n > n^*. In spite of further increasing numbers of components in the mixture the risk remains almost constant. For all situations, where the risk decreases with increasing n these numbers n^*, therefore, can be considered as necessary numbers of components in mixtures, n^* depends on q, x and a. Nevertheless, a global and rough conclusion can be formulated: In many situations one obtains necessary numbers of 30–40 components for a0 and 20–30 components for a = 0.     

New media for detection and counting of clostridia in foods

The growth of pure cultures of Clostridium perfringens (ATCC 12922) and Cl. sporogenes (PA 3679) in five non-selective media, fluid thioglycollate medium (FTM), rapid perfringens medium (RPM), Columbia broth Malthus (CBM), reinforced clostridial medium (RCM) and lactose sulphite (LS), was monitored using conductance measurements with a Malthus analyser. Only FTM and CBM gave useful results. The correlation of log₁₀ plate counts on blood agar of the pure strain of Cl. sporogenes with detection times in FTM was highly significant ( r = 0·96, n = 73), and with detection times in CBM less so ( r = −0·909, n = 33). The correlation of log₁₀ counts on tryptose sulphite neomycin medium (TSN) of wild strains of Cl. sporogenes and Cl. perfringens with detection times with FTM in meat was also highly significant ( r = 0·933, n = 54).     

Counting mycobacteria in infected human cells and mouse tissue: a comparison between qPCR and CFU

Due to the slow growth rate and pathogenicity of mycobacteria, enumeration by traditional reference methods like colony counting is notoriously time-consuming, inconvenient and biohazardous. Thus, novel methods that rapidly and reliably quantify mycobacteria are warranted in experimental models to facilitate basic research, development of vaccines and anti-mycobacterial drugs. In this study we have developed quantitative polymerase chain reaction (qPCR) assays for simultaneous quantification of mycobacterial and host DNA in infected human macrophage cultures and in mouse tissues. The qPCR method cannot discriminate live from dead bacteria and found a 10- to 100-fold excess of mycobacterial genomes, relative to colony formation. However, good linear correlations were observed between viable colony counts and qPCR results from infected macrophage cultures (Pearson correlation coefficient [r] for M. tuberculosis = 0.82; M. a. avium = 0.95; M. a. paratuberculosis = 0.91). Regression models that predict colony counts from qPCR data in infected macrophages were validated empirically and showed a high degree of agreement with observed counts. Similar correlation results were also obtained in liver and spleen homogenates of M. a. avium infected mice, although the correlations were distinct for the early phase (< day 9 post-infection) and later phase (≥ day 20 post-infection) liver r = 0.94 and r = 0.91; spleen r = 0.91 and r = 0.87, respectively. Interestingly, in the mouse model the number of live bacteria as determined by colony counts constituted a much higher proportion of the total genomic qPCR count in the early phase (geometric mean ratio of 0.37 and 0.34 in spleen and liver, respectively), as compared to later phase of infection (geometric mean ratio of 0.01 in both spleen and liver). Overall, qPCR methods offer advantages in biosafety, time-saving, assay range and reproducibility compared to colony counting. Additionally, the duplex format allows enumeration of bacteria per host cell, an advantage in experiments where variable cell death can give misleading colony counts.     

Naloxone exerts a dose-dependent gastric cytoprotective effect

Previous work has shown that naloxone inhibits the ulcerogenic effects of indomethacin and stress, although the site, mechanism or dose are unknown. We investigated whether naloxone possessed gastric cytoprotective properties, generating a dose-response curve existed for both intragastric (IG) and intravenous (IV) administration. One hundred and two rats were subjected to a four hour period of restraint, with the last two hours at 4 degrees C. Naloxone was given hourly during restraint at doses of 0 (Control), 1, 5, 10, 20 mg/kg. After sacrifice, the residual gastric volume, and pH were measured and the number of mucosal lesions scored. The cytoprotection offered by naloxone was different from control (p = 0.0001), with the intravenous route having a greater effect (p = 0.038). While this protective effect did not correlate with changes in gastric acidity, it correlated with the dose of naloxone.     

唐鱼仔鱼耳石的形态发育及日轮

观察了实验室人工繁殖饲养的唐鱼(Tanichthys albonubes)仔鱼耳石形态发育,研究了其生长轮的沉积规律。唐鱼仔鱼耳石长径与鱼体全长(TL)均呈线性相关,其关系式为:微耳石Dl=0.019 6TL-0.031 0(r=0.961 6,P<0.001,n=218),矢耳石Ds=0.027 6TL-0.043 7(r=0.924 0,P<0.001,n=219),星耳石Da=0.016 6TL-0.004 1(r=0.369 6,P<0.001,n=44)。仔鱼耳石上第一个轮纹在孵出后第2 d形成,生长轮数目与仔鱼日龄(D)呈线性相关,其斜率与1无显著差异,因此生长轮为日轮,其关系式为:微耳石LI=1.006D-1.700 1(r=0.994 2,P<0.001,n=205),矢耳石SI=0.953 8D-0.911 6(r=0.993 5,P<0.001,n=161)。生长过程中矢耳石形状变化较大,星耳石出现时间较晚,而微耳石形状稳定,日轮可读性较好,故更适合作为日轮研究的材料。     

硫酸酯酶2型基因体内表达促进化疗药物诱发的小鼠骨髓抑制恢复作用研究

采用半定量RT-PCR和重组基因体内表达法观察了硫酸酯酶2基因（Sulfatase 2,Sulf2）在5-氟脲嘧啶（5-Fluorouracil, 5-Fu）诱发的小鼠骨髓抑制和再生过程中作用。结果表明：Sulf2在小鼠骨髓抑制和再生过程中呈现先上升,后下降的动态表达;电转pcDNA3.1-Sulf2基因实验组外周血白细胞数和血小板数在5-Fu注射后第7天分别为(1216.7±457.9)/μl和(8.1±5.4)万/μl,明显低于对照组［分别为(1691.7±228.9)/μl和(14.7±2.1)万/μl］,实验组单条腿骨髓细胞总数在第7天为(94.2±21.1)万,显著低于对照组（173±59.9）万,但在第11天为(585±337.9)万,又显著地高于对照组（255±65.3）万,实验组第7天10000个骨髓细胞总集落形成数为(9±8.4),显著低于对照组（39±12.2),统计均有显著性差异（p<0.05）。这些结果提示Sulf2可能对5 Fu诱发的小鼠骨髓抑制后的再生具有促进作用。     

Sensitive detection of Escherichia coli O157:H7 in food and water by immunomagnetic separation and solid-phase laser cytometry

Rapid, direct methods are needed to assess active bacterial populations in water and foods. Our objective was to determine the efficiency of bacterial detection by immunomagnetic separation (IMS) and the compatibility of IMS with cyanoditolyl tetrazolium chloride (CTC) incubation to determine respiratory activity, using the pathogen Escherichia coli O157:H7. Counterstaining with a specific fluorescein-conjugated anti-O157 antibody (FAb) following CTC incubation was used to allow confirmation and visualization of bacteria by epifluorescence microscopy. Broth-grown E. coli O157:H7 was used to inoculate fresh ground beef (<17% fat), sterile 0.1% peptone, or water. Inoculated meat was diluted and homogenized in a stomacher and then incubated with paramagnetic beads coated with anti-O157 specific antibody. After IMS, cells with magnetic beads attached were stained with CTC and then an anti-O157 antibody-fluorescein isothiocyanate conjugate and filtered for microscopic enumeration or solid-phase laser cytometry. Enumeration by laser scanning permitted detection of ca. 10 CFU/g of ground beef or <10 CFU/ml of liquid sample. With inoculated meat, the regression results for log-transformed respiring FAb-positive counts of cells recovered on beads versus sorbitol-negative plate counts in the inoculum were as follows: intercept = 1.06, slope = 0.89, and r2 = 0. 95 (n = 13). The corresponding results for inoculated peptone were as follows: intercept = 0.67, slope = 0.88, and r2 = 0.98 (n = 24). Recovery of target bacteria on beads by the IMS-CTC-FAb method, compared with recovery by sorbitol MacConkey agar plating, yielded greater numbers (beef, 6.0 times; peptone, 3.0 times; water, 2.4 times). Thus, within 5 to 7 h, the IMS-CTC-FAb method detected greater numbers of E. coli O157 cells than were detected by plating. The results show that the IMS-CTC-FAb technique with enumeration by either fluorescence microscopy or solid-phase laser scanning cytometry gave results that compared favorably with plating following IMS.     

Increased cell proliferation in chronic Helicobacter pylori positive gastritis and gastric carcinoma--correlation between immuno-histochemistry and Tv image cytometry.

BACKGOUND: Epithelial cell proliferation activity has been reported both to be unaltered and increased in Helicobacter pylori (H. pylori) associated chronic gastritis. The proliferation rate decreased following H. pylori eradication, but results are controversial whether this change is dependent on the success of eradication. We compared the cell proliferation activity of H. pylori positive and negative gastric epithelial biopsies in chronic gastritis with and without intestinal metaplasia (IM) and gastric cancer by the expression of proliferation cell nuclear antigen (PCNA) and Tv image cytometry, and assessed the effect of H. pylori eradication on the cell proliferation rate in the gastric epithelium. METHODS: Brush smears and antral biopsies were taken from 70 patients (42 men, 28 women, mean age 58+/-15 y.o.) on routine endoscopy. Patients were divided into four groups according to the histology; normal epithelia (n = 10), chronic gastritis without IM (n = 24), chronic gastritis with IM (n = 20), and gastric carcinoma (n = 16). Thirty-three patients were H. pylori positive, and success of eradication was controlled in 24 cases. Cell proliferation was measured by immunohistochemistry using PCNA labeling index (LI) and by Tv image cytometry evaluating 12 morpho- and densitometric parameters of each nuclei and 6 additional parameters of each smear. RESULTS: PCNA LI, DNA index and S + G2 ratio were all higher in chronic gastritis than in the normal epithelium, and were further increased in carcinoma. The lower PCNA LI observed in chronic gastritis with IM corresponds to the lower S phase ratio determined by Tv image analysis. In H. pylori positive cases, the proliferation activity was 69.3+/-13.05% prior to the eradication and it decreased to 55.8+/-23.31% after the successful eradication therapy. When immunohistochemistry was compared with Tv image cytometry, PCNA LI significantly correlated with the percentage of cells in GL phase (r = -0.415) and S phase (r = 0.385), Integrated Optical Density mean (r = 0.598), density maximum (r'= 0.608), surface (r = 0.670), layers (r = 0.638), diameter minimum (r = 0.619), diameter maximum (r = 0.730) and perimeter (r = 0.501), respectively (p < 0.05). CONCLUSIONS: Epithelial cell turnover is increased in chronic gastritis with or without IM, and in gastric carcinoma. The lower PCNA LI observed in chronic gastritis with IM corresponds to the lower S phase ratio determined by Tv image analysis. Cell proliferation decreases after successful H. pylori eradication. Both methods proved to be reliable for the determination of epithelial cell proliferation.     

Effect of daily oral omeprazole on 24 hour intragastric acidity.

Twenty four hour intragastric acidity was measured in nine patients with duodenal ulcer before and after one week of treatment with oral omeprazole 30 mg daily, a drug that inhibits gastric secretion by inhibition of parietal cell H+K+ adenosinetriphosphatase (ATPase). Omeprazole virtually eliminated intragastric acidity in all patients: the median 24 hour intragastric pH rose from 1.4 to 5.3 and the mean hourly hydrogen ion activity fell from 38.50 to 1.95 mmol(mEq)/1 (p less than 0.001). This inhibition of 24 hour intragastric acidity is more profound than that previously reported with either cimetidine 1 g daily or ranitidine 300 mg daily.     

Cytotaxonomic analysis of South American species of Vernonia (Vernonieae: Asteraceae)

Chromosome numbers in 48 populations belonging to 31 species of Vernonia from South America have been determined. First chromosome counts are reported for V. propinqua var. canescens (2 n = 20), V. sceptrum (2 n = 80), V. rufogrisea (2 n = 32), V. heringeri (2 n = 32), V. hovaefolia (2 n = 64), V. hystricosa (2 n = 128), V. obtusata (2 n = 64), V. pseudoincana (2 n = 32), V. rubricaulis var.◊ australis (2 n = 64) and V. rugulosa (2 n = 30). The basic chromosome numbers x = 10, 14, 15, 16 and 17 were confirmed for New World species of Vernonia . Together with previous records, these numbers suggest that the evolution of Vernonieae has occurred through a combination of polyploidy and aneuploidy. Taxonomic implications of certain counts are also discussed.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 401–408.