Antigenic Relationship Between Pythium insidiosum de Cock et al. 1987 and its Synonym Pythium destruens Shipton 1987

Antigens and rabbit-antisera from holotypes of Pythium insidiosum and P. destruens were prepared to elucidate their antigenic relationship. The antigens and rabbit-antisera of P. insidiosum as well as P. destruens used as a reference system showed that both shared three precipitin bands in common. The antigen and rabbit-antisera of P. destruens and P. insidiosum used as a reference system against other strains isolated from humans and animals with pythiosis, also showed three precipitin bands in common. When we used sera taken from horses with proven pythiosis against antigens of P. insidiosum and P. destruens, six common bands were observed. We concluded that the etiologic agent of pythiosis is a single species P. insidiosum, and could be identified by serologic methods.     

Orbital pythiosis: a non-fungal disease mimicking orbital mycotic infections, with a retrospective review of the literature

In the past decade there have been four well-documented cases of orbital pythiosis caused by Pythium insidiosum. All were recorded in apparently healthy children. Although pythiosis seems to be a rare infection in humans, we recently conducted a review of the medical literature to investigate misdiagnosed cases of orbital pythiosis in the past 100 years in children. To track putative cases of orbital pythiosis, we first identified orbital cases initially diagnosed as fungal infections. We were particularly interested in cases (a) involving apparently young healthy hosts, (b) the presence of hyaline, aseptate hyphal elements in the infected tissues, (c) the morphological features of the hyphal elements, (d) the presence of an eosinophilic granulomatous reaction with the Splendore-Hoeppli phenomenon around the mycelial elements, (e) resistance to antifungal therapy, (f) outcome after therapy, if any, and (g) cultural strategies. This study showed that indeed, there had been five other recorded cases of orbital infections, all in young children in the USA, with characteristics consistent with infections caused by P. insidiosum. The reports had described those cases of orbital-cranial-arterial diseases as patients with aspergillosis (one case), penicilliosis infection (one case), and zygomycosis (three cases). We reviewed those anomalous cases and discuss details about their clinical, pathologic, therapeutic, and etiologic evidence used to reclassify them as putative cases of orbital pythiosis.     

Pathogenicity of some Species of Pythium Pringsheim on Certain Fresh Water Temperate Fishes/Pathogenität einiger Arten von Pythium Pringsheim auf Süßwasserfische gemäßigter Breiten

Summary: Eight species of Pythium, P. aphanidermatum, P. debaryanum, P. inflatum, P. echinulatum, P. pulcharum, P. spinosum, P. undulatum and P. vaxans were studied for their parasitic capability in temperate fresh water fishes and found to be pathogenic in laboratory condition. Puntius ticto and P. conchonius were more sensitive than Carassius auratus. Nemacheilus rupicola was found immune to all the Pythium species. Fungal species were also found variable in their parasitic capability.
Zusammenfassung: Unter Laborbedingungen wurde die Fáhigkeit zum Parasitismus bei Süßwasserfischen gemäßigter Breiten mit 8 Arten der Gattung Pythium (P. aphanidermatum, P. debaryanum, P. inflatum, P. echinulatum, P. pulcharum, P. spinosum, P. undulatum und P. vaxans) geprüft. Puntius ticto und P. conchonius reagierten empfindlicherals Carassius auratus. Nemachilus rupicola war gegen alle Pythium-Arten immun. Auch die einzelnen Pilz-Spezies wiesen eine unterschiedliche Fáhigkeit zum Parasitismus auf.     

Prevalence of biofilm formation in clinical isolates of Candida species causing bloodstream infection

Candida species are the fourth most common cause of nosocomial invasive infections. Biofilm formation is recognised as one virulence factor of Candida species. A total of 243 Candida albicans, 81 C. glabrata, 33 C. parapsilosis, 14 C. dubliniensis, 8 C. tropicalis, 8 C. lusitaniae, 5 C. krusei and 1 C. pelliculosa isolates causing bloodstream infections were evaluated for biofilm formation. The biofilm formed on silicone elastomer preincubated with human serum was quantified by estimation of the metabolic activity through XTT assay and visualised by light and scanning electron microscopy. Forty per cent of the C. albicans isolates formed biofilm compared to 88.7% of the non‐albicans Candida isolates (P < 0.0001). Among non‐albicans Candida spp., biofilm formation was most commonly observed in C. tropicalis and C. lusitaniae (100%), followed by C. glabrata (95%), C. dubliniensis (85.7%) and C. parapsilosis (66.7%). A quantitative correlation was observed between the amount of biofilm observed microscopically, and that determined by metabolic activity measurements. The biofilms of all Candida species were composed of basal yeast cells with the exception of C. parapsilosis which produced biofilms consisting of pseudohyphae and aggregated yeast cells. These results suggest that biofilm formation as a virulence factor might have a higher significance for non‐albicans Candida species than for C. albicans.     

小管形成实验在肿瘤微血管形成中的应用研究

肿瘤的增殖与侵袭有赖于肿瘤新生微血管的形成,破坏或者抑制此过程就能切断肿瘤生长的“营养与能源”,因此肿瘤血管生成抑制因子、抗血管生成的药物及研究方法已成为人们研究的热点。本文就小管形成实验在肿瘤微血管生成的应用及影响小管实验管腔形成的各项因素做一综述。     

Inhibition of Heinz Body Induction in an inVitro Model and Total Antioxidant Activity of Medicinal Thai Plants

Herbs have been used for medicinal purposes for centuries and known to possess antioxidant properties that ‍may help to reduce the risk of chronic diseases, cardiovascular disease, and cancer. We screen aqueous extracts from ‍20 medicinal plants in Thailand that were believed to possess anti-tumor activity, help immune-stimulating property ‍and maintain blood stasis. The antioxidant activities were investigated in two bioassays. Firstly, we demonstrated ‍inhibition of Heinz bodies induction caused by oxidants under in vitro condition. The percentages of Heinz body ‍inhibition activity in plant extracts from Terminalia citrina, Cassia timoriensis, and Derris elliptica were the highest ‍followed by Anamirta cocculus, and Oroxylum indicum respectively. In addition, we investigated total antioxidant ‍activity in plant extracts by improved ABTS radical cation decolorization assay. The total antioxidant activity of the ‍extract from Terminalia citrina was also the highest activity followed by Ficus pubigera, Derris elliptica, Anamirta ‍cocculus, Caesalpinia sappan, and Oroxylum indicum respectively. Our results suggest medicinal Thai plants as ‍valuable sources of antioxidants, which may have a potential anti-carcinogenic activity.     

Biofilm production in oral Candida isolates from HIV‐positive individuals from Pune,India

Biofilm formation is implicated as a potential virulence factor in Candida species and carries important clinical repercussions because of their increased resistance to antifungal treatment, ability to withstand host defences and to serve as a reservoir for continuing infections. The present study was undertaken to determine the biofilm production among oral Candida isolates from HIV‐positive and HIV‐negative individuals from Pune, India. Biofilm formation was determined using the spectrophotometric or microtitre plate method in 182 Candida isolates, of which 154 were from HIV‐positive and 28 were from HIV‐negative individuals. A total of 63.2% of the Candida isolates were biofilm producers. Significantly increased biofilm forming abilities both qualitatively as well as quantitatively were observed in Candida isolates from HIV‐positive individuals (66.2%) compared to isolates from HIV‐negative ones (46.4%), (P– 0.041). Eighty‐one (59.6%) C. albicans isolates and 34 (73.9%) non –C. albicans Candida (NCAC) showed biofilm positivity. The NCAC showed significantly greater intensity of biofilm formation compared to the C. albicans, P– 0.032. Our results thus show the enhanced biofilm forming abilities of oral Candida isolates from HIV‐infected individuals compared to HIV‐uninfected ones and highlight the important role played by biofilm formation in the pathogenesis of NCAC isolates.     

Usefulness of postoperative hip irradiation in the prevention of heterotopic bone formation in a high risk group of patients

Heterotopic ossification is a complication of total hip arthroplasty in 14 to 30% of patients. Significant functional impairment will occur in up to 28% of patients with ectopic bone. The high risk group includes those with preexisiting heterotopic bone in either hip, those suffering from hypertrophic osteoarthritis or ankylosing spondylitis and patients who have had multiple procedures on the hip. Fifty-eight patients (67 hips) were irradiated after surgical removal of ectopic bone (53 hips) or received radiation prophylaxis of heterotopic ossification (14 hips). Ninety-five percent of patients had either no bone visible or insignificant amounts of ectopic bone visible on postoperative hip X-rays. Only 5% of patients showed significant persistence of ectopic bone. Postoperative hip function was dramatically improved compared to preoperative function in all patients treated. The importance of early commencement of irradiation is emphasized.     

Effect of acute and chronic ethanol intake on metastasis formation in rat liver

The effect of acute ethanol intoxication and prolonged intake of ethanol on metastasis formation in the liver was studied in the rat. The tumour cells used were derived from a pharmacologically induced colon carcinoma (NGW 1) and were injected intraportally. Acute ethanol intoxication at the time of injection was associated with a liver weight of 13.29 +/- 0.89 gm two weeks later, compared to 8.43 +/- 0.51 gm in controls. Daily intake of ethanol for eight weeks resulted in a mild reduction of platelets. The liver weight in two groups was 7.31 +/- 0.50 gm and 12.19 +/- 1.40 gm three weeks after intraportal injection of cancer cells as compared to 9.53 +/- 1.11 gm and 19.63 +/- 1.67 gm in controls. The results indirectly supported the hypothesis that acute ethanol intoxication causes increased platelet activity and confirmed earlier results showing the importance of platelets for metastasis formation.     

A systematic review of seroma formation following drain-free mastectomy

BackgroundSeroma is a common complication after mastectomy. The aim of this review is to elucidate whether closed suction drainage can safely be omitted in patients undergoing mastectomy when assessing seroma formation and its complications. The second aim is to assess the influence of flap fixation on seroma related complications, as there is existing evidence showing that combining mastectomy with flap fixation may make the use of drainage systems obsolete.Search & selectionA review of the literature was performed and articles that compared mastectomy with drainage and mastectomy without drainage were selected. Due to the small number of eligible studies, no selection based on whether flap fixation was performed was possible. If outcome was described in terms of seroma formation or seroma related complications, papers were eligible for inclusion. Studies older than 20 years, animal studies, studies not written in English and studies with male patients were excluded.ResultsA total of eight articles were eligible for inclusion. Four prospective studies and four retrospective studies were included. In four studies, flap fixation was performed. Frequency of seroma formation as well as seroma that required intervention was reported. The included studies demonstrated that omitting closed suction drainage does not lead to a higher incidence of seroma formation in patients undergoing mastectomy.ConclusionDespite substantial heterogeneity, there is evidence that drainage can safely be omitted without exacerbating seroma formation and its complications. A well-powered, randomized controlled trial evaluating the effect of drainage omission on seroma formation, with or without flap fixation, is needed.     

Dosimetry of hip irradiation for the prevention of heterotopic bone formation after arthroplasty

Purpose: The dosimetry of hip irradiation for the prevention of heterotopic bone formation following arthroplasty is complicated by the use of custom shielding in the treatment portal, and the fact that irradiation is usually required during a 48 hour period following surgery. Both the machine output and depth dose factors of the resulting fields are modified by the presence of the shielding blocks. A simplified dosimetric approach, based on correction factors for both the output and depth dose as a function of field geometry is presented for various megavoltage energy beams.

Materials and Methods: Measurements of relative dose factors (RDF) and percentage depth dose (PDD) were carried out for different combinations of field size, block size and separation between adjacent blocks. Both RDF and PDD measurements were made in a water phantom. Ratios of RDF and PDD were obtained by dividing individual measurements or curves by the corresponding values for the open field (i.e., without blocks). The average values of these ratios constitute the correction factors to be applied for a given MU or treatment time calculation.

Results: Extensive RDF and PDD measurements reveal that for the field and block dimensions of interest the correction factors for RDF can be parameterized as a function of separation between two adjacent blocks and beam energy alone and the depth correction factors are additionally only a function of depth. The correction factors for depth dose are equally valid for fixed source-skin distance techniques (that use PDD) and fixed source-axis distance techniques (that use TMR).

Conclusion: A simple model for the calculation of output in hip irradiation is presented for the situation where the use of computer-based algorithms may not be practical. The model accurately predicts the RDF of the treatment portal to within 2% and the PDD to within 2% for the range of field sizes, block sizes, block gaps and beam energies of interest ignoring other variables.     

The effects of parathyroid hormone fragments on bone formation and their lack of effects on the initiation of colon carcinogenesis in rats as indicated by preneoplastic aberrant crypt formation

The parathyroid hormone (PTH) and some of its fragments and analogs stimulate bone growth in various animal models and humans and one of them (hPTH-(1–34)) has been approved by the USFDA for treating osteoporosis. However, there are reports that PTH can stimulate the PI-3 kinase/mitogen-activated protein kinases-mediated proliferation of rat enterocytes and that primary hyperparathyroidism in humans is associated with an increased incidence of colon cancer. Here we have investigated the ability of two PTH fragments, hPTH-(1–34)NH₂ and [Leu²⁷]cyclo(Glu²²-Lys²⁶)hPTH-(1–31)NH₂ to initiate colon carcinogenesis or increase the initiatory activity of the widely used colon carcinogen azoxymethane (AOM). The initiation of colon carcinogenesis by AOM was indicated by the very early appearance of aberrant crypt foci. While both PTH peptides strongly stimulated femoral bone formation, they did not cause the appearance of ACFs or affect the number or the distribution along the colon of AOM-induced ACFs. Nor did AOM affect the PTHs’ ability to stimulate bone formation. Thus, a relatively short PTH treatment that is long enough to strongly stimulate bone formation does not initiate colon carcinogenesis in rats.     

IL-17在NSCLC淋巴管形成和侵袭中的作用

目的 探讨白细胞介素-17(IL-17)在非小细胞肺癌(NSCLC)淋巴管形成和侵袭中的作用.方法 收集手术切除的NSCLC组织标本40例,采用免疫组织化学法检测NSCLC组织中IL-17表达情况及淋巴管密度;采用MTT实验检测IL-17对淋巴管内皮细胞(LEC)增殖的影响;采用Transwell实验和淋巴管形成实验检测IL-17对LEC细胞迁移和管样结构形成的影响.结果 IL-17蛋白阳性表达患者的淋巴管密度高于IL-17蛋白阴性表达患者(P﹤0.05);0、0.5、1.0、5.0和10.0 ng/ml IL-17对LEC增殖活力的影响比较,差异无统计学意义(P﹥0.05);对照组和IL-17组透膜细胞数比较,差异无统计学意义(P﹥0.05);LLC组透膜细胞数为(58.70±12.52)个,高于对照组和IL-17组(P﹤0.05);LLC+IL-17组透膜细胞数最高,为(98.82±20.16)个,高于对照组、IL-17组和LLC组(P﹤0.05);对照组和IL-17组管样结构分支数比较,差异无统计学意义(P﹥0.05);LLC组管样结构分支数高于对照组和IL-17组(P﹤0.05);LLC+IL-17组管样结构分支数最高,为(155.82±29.92)个,高于对照组、IL-17组和LLC组(P﹤0.05).结论 IL-17对LEC的增殖、迁移和管样结构形成无直接的促进作用,但可通过对NSCLC细胞的作用间接促进LEC的侵袭和转移.     

Q61R和V112A突变的HRAS基因在NIH小鼠体内诱发肿瘤的实验研究

目的：分析含有HRAS（V112A）基因及其G12C、G12C、Q61R和G12C/G12C/Q61R突变体的质粒DNA在NIH小鼠体内的致癌性。方法：从人结肠癌DiFi细胞中扩增含有V112A突变的HRAS（V112A）基因,采用PCR点突变法在HRAS（V112A）中分别引入G12C[HRAS（V112A/G12C）]、G12C[HRAS（V112A/G12C）]、Q61R[HRAS（V112A/Q61R）]或3位点联合突变[HRAS（V112A/G12C/G12C/Q61R）],将HRAS（V112A）及上述突变基因克隆入真核表达载体pCDNA3.1（+）,Western blot确证HRAS（V112A）及各突变体可体外表达后,每种质粒按每只100 μg剂量皮内注射6~8周龄雌性NIH小鼠,阴性对照组注射PBS,每组8只小鼠,持续观察小鼠致瘤情况。注射后4个月,取小鼠瘤样组织分别采用PCR和Western blot方法检测病变组织中的HRAS基因及其表达产物。结果：从DiFi细胞中成功扩增出含有V112A突变的HRAS（V112A）基因,并构建4个突变体,体外转染结果表明各HRAS均可在L929细胞中表达。重组质粒注射小鼠后,HRAS（V112A）组有4只小鼠注射后4个月于注射部位出现增生样改变,该病变在1个月后自愈;HRAS（V112A/Q61R）组有1只小鼠于注射后4个月出现明显的瘤样增生。至观察期末,HRAS（V112A/G12C）、HRAS（V112A/G12C）和HRAS（V112A/G12C/G12C/Q61R）组小鼠均未出现可见增生样结节。病变组织的PCR和Western blot检测结果表明HRAS（V112A）组小鼠增生样组织和HRAS（V112A/Q61R）组小鼠肿瘤组织中均有对应的HRAS基因存在和表达。结论：HRAS（V112A）可在NIH小鼠体内导致注射部位皮肤的增生样改变,含有Q61R突变的HRAS（V112A）可在NIH小鼠体内诱导肿瘤形成,含有G12C、G12C及G12C/G12C/Q61R突变的HRAS（V112A）在小鼠体内不会引起明显病变。     

Rimonabant inhibits human colon cancer cell growth and reduces the formation of precancerous lesions in the mouse colon

The selective CB1 receptor antagonist rimonabant (SR141716) was shown to perform a number of biological effects in several pathological conditions. Emerging findings demonstrate that rimonabant exerts antitumor action in thyroid tumors and breast cancer cells. In our study, human colorectal cancer cells (DLD‐1, CaCo‐2 and SW620) were treated with rimonabant and analyzed for markers of cell proliferation, cell viability and cell cycle progression. Rimonabant significantly reduced cell growth and induced cell death. In addition, rimonabant was able to alter cell cycle distribution in all the cell lines tested. Particularly, rimonabant produced a G2/M cell cycle arrest in DLD‐1 cells without inducing apoptosis or necrosis. The G2/M phase arrest was characterized by a parallel enhancement of the number of mitoses associated to elevated DNA double strand breaks and chromosome misjoining events, hallmarks of mitotic catastrophe. Protein expression analyses of Cyclin B1, PARP‐1, Aurora B and phosphorylated p38/MAPK and Chk1 demonstrated that rimonabant‐induced mitotic catastrophe is mediated by interfering with the spindle assembly checkpoint and the DNA damage checkpoint. Moreover, in the mouse model of azoxymethane‐induced colon carcinogenesis, rimonabant significantly decreased aberrant crypt foci (ACF) formation, which precedes colorectal cancer. Our findings suggest that rimonabant is able to inhibit colorectal cancer cell growth at different stages of colon cancer pathogenesis inducing mitotic catastrophe in vitro. © 2009 UICC.     

Risk factors to cause tooth formation anomalies in chemotherapy of paediatric cancers

This study aimed to investigate the risk factors of tooth formation anomalies in anti‐cancer chemotherapies. Long‐term survivors treated by conventional chemotherapy (n = 26), conventional chemotherapy with high‐dose chemotherapy (HDC) (n = 14), and HDC with total body irradiation (TBI) (n = 6) were analysed for the incidence of tooth agenesis, microdonts, and short‐rooted teeth. The tooth agenesis and/or microdonts were found in second premolars and second molars, but not in first molars or central incisors. The ratio of subjects with tooth agenesis and/or microdonts was 66.7% and 18.2% in subjects administered conventional chemotherapy at <4 years and ≥4 years of age, respectively, while it was 100% and 25% in subjects administered HDC at <4 years and ≥4 years of age. The incidence of tooth formation anomalies did not related with the duration of conventional chemotherapy but increased by HDC. The incidence of tooth formation anomalies did not show significantly differences between the HDC with and without TBI groups, and was higher in busulfan‐administered subjects than in subjects given cyclophosphamide. It may be concluded that the high‐risk group of tooth agenesis is the subjects with HDC under 4 years of age. However, protocols of conventional chemotherapy are not an important risk factor to cause the tooth formation anomalies.     

Inhibitory activity of thymol against the formation and viability of Candida albicans hyphae

As the capacity of Candida albicans to produce hyphae is considered an important virulence factor in the pathogenesis of candiasis, the aim of this study was to investigate whether thymol, the major component of thyme oil, can interfere with the filamentous forms of Candida albicans and their viability. The morphological transition from yeasts to filamentous forms was investigated by analysing the morphological index (MI), which classifies the differentiated forms and blastoconidia; viability was investigated by means of fluorescence microscopy using a new SYTO-9 and propidium iodide method previously used to stain only blastoconidia. Without thymol, there was an average of 94.00 +/- 3.06% hyphal forms. After 6 h of incubation with 1x MIC (125 microg ml(-1)), 1/2x MIC and 1/4x MIC of thymol, filamentation was, respectively, 14.33 +/- 8.25%, 28.33 +/- 7.17% and 45.67 +/- 8.09% in comparison with control (all statistically significant). In the absence of thymol, viable cells accounted for an average of 93.00 +/- 4.00% whereas, after 6 h of incubation with 1x MIC, 1/2x MIC and 1/4x MIC of thymol, the presence of 54.33 +/- 1.86%, 29.00 +/- 3.61% and 23.00 +/- 2.52% of yellow-orange coloured forms indicated damaged membranes and reduced viability. Our findings show that thymol interferes with the formation and viability of hyphae. This can be attributed to the characteristics of thymol disturbing Candida cell membranes and metabolism, probably by affecting fungal cell-wall synthesising enzymes.     

非小细胞肺癌血管生成的螺旋CT增强扫描检测

 目的　评价螺旋CT增强扫描检测非小细胞肺癌（NSCLC）血管生成及血流动力学特点,为肿瘤研究和临床诊断及治疗提供更多信息。方法　对病理证实的152例NSCLC患者,进行螺旋CT双期增强扫描,分析血流灌注的特点。并将病灶增强形态表现与组织学相对照,对其相关性进行分析。结果　癌灶CT强化峰值（PV）低分化>中分化>高分化,其中45～70 HU 63例,20～45 HU 78例,10～20 HU 11例。异常小动脉67例,异常血湖（窦）显影23例,花蕊状35例。结论　根据螺旋CT双期增强扫描可准确检出和量化癌灶血管生成,对临床治疗NSCLC方案的制订和肿瘤综合治疗有很高的指导价值。