Effect of hemoglobin on the development ofPseudomonas aeruginosa infection

The disease caused by injection ofP. aeruginosa suspension in a hemoglobin solution was more severe (greater weight loss and larger abscesses in primary foci) than that induced by the same dose of the microbe in Hanks' solution (control). It was supposed that in the control the viability of the microorganisms was suppressed by iron deficiency in surrounding tissues, which was particularly pronounced upon accumulation in a limited space of great numbers of bacterial cells competing with each other for iron. Iron released from hemoglobin provides better conditions for the development ofP. aeruginosa. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 3, pp. 351–352, March, 1997     

Evaluation of ciprofloxacin in the treatment ofPseudomonas aeruginosa infections

The efficacy and safety of ciprofloxacin in the treatment ofPseudomonas aeruginosa infections was evaluated in 72 patients suffering from upper urinary tract infection (19 patients), deep soft tissue infection (16), chronic osteomyelitis (12), abscess (7), chronic otitis media (6), otitis externa (3) and bronchopneumonia (9). Forty-eight patients received an oral dose of 500 mg or 750 mg b.i.d. and five patients an i.v. dose of 200 mg b.i.d., while 19 patients were given both oral and parenteral doses. The duration of therapy ranged from seven days to more than four months. The MICs of ciprofloxacin for thePseudomonas aeruginosa strains isolated were in the range < 0.06–2 mg/l; 36% of the strains were resistant to all other available antibiotics. At follow-up after a minimum of six months the clinical success rate was 75% and the infecting organism was permanently eradicated in 49% of the patients. In nine patients the organism developed resistance, particularly when the initial MIC was higher than 0.5 mg/l. No significant adverse reactions were observed. Ciprofloxacin is the first antipseudomonal antimicrobial agent which can be administered orally and therefore fulfills a need in chemotherapy.     

Use of ciprofloxacin in the treatment ofPseudomonas aeruginosa infections

The therapeutic efficacy and safety of ciprofloxacin was studied in 30 patients withPseudomonas aeruginosa infections. In 20 patients ciprofloxacin was given alone and in 10 patients (including 8 compromized hosts) in combination with an aminoglycoside (9) or azlocillin (1). Ciprofloxacin was given in doses of 500 mg orally or 200–300 mg i. v. every 12 h. In patients receiving only ciprofloxacin clinical cure with eradication of bacteria was obtained in 15 patients (75%) with infections of bone and joint (6), skin and soft tissue (4), lung (2), middle ear (2) and CSF (1). Two patients with lymphoma andPseudomonas aeruginosa pneumonia died. In patients receiving combination therapy a definite therapeutic success was achieved in four (40%). Three patients withPseudomonas aeruginosa septicemia died. In seven patients nine bacterial strains with decreasing susceptibility of ciprofloxacin (increase in MIC from 0.5g/ml to 2–16 g/ml) were selected (6Pseudomonas aeruginosa, 1Enterobacter cloacae, 1Serratia marcescens, 1Staphylococcus aureus). Ciprofloxacin was well tolerated. This new quinolone seems to be suitable for single drug treatment ofPseudomonas aeruginosa infections in patients with normal host defense mechanisms, while its therapeutic potential in compromized hosts requires further evaluation.     

Evaluation of the E test in testing susceptibility ofPseudomonas aeruginosa to tobramycin

The E test, a new technique for measuring MICs of antimicrobial agents with the ease of disc diffusion tests, was evaluated in testing the susceptibility of 94 clinical isolates ofPseudomonas aeruginosa to tobramycin. The use of the E test was found acceptable; 93 % of the MIC results were within one log₂ dilution step and 100 % were within two log₂ dilution steps when the MICs obtained by the E test were compared to those obtained by the conventional agar dilution method. When the E test was compared to the broth microdilution method the corresponding figures were 84 % and 100 %, respectively.     

In vivo production of exotoxin A and its role in endogenous Pseudomonas aeruginosa septicemia in mice.

We have examined the production of Pseudomonas aeruginosa exotoxin A (ETA) and its role in endogenous bacteremia in mice. Mice given P. aeruginosa D4 orally died of bacteremia between days 10 and 13 following cyclophosphamide-induced leukocytopenia. In this model, serum endotoxin was detected beginning on day 7 by the Limulus assay and P. aeruginosa was cultured from blood beginning on day 9. ETA and tumor necrosis factor alpha (TNF) were also detected in serum by enzyme-linked immunosorbent assay beginning on day 9. Purified ETA did not stimulate the production of TNF in normal mice primed with a synthetic derivative of muramyl dipeptide in the absence of endotoxin. However, ETA enhanced and primed endotoxin-induced TNF production in mice. The mortality rate of mice given ETA mutant PAO-PRI (5.0%) was significantly lower than that of mice given the parent strain (78.8%). These data indicate that ETA may be an important factor in the occurrence of P. aeruginosa bacteremia and/or the death of mice. Also, ETA may be responsible for enhancing the production of a lethal dose of TNF in the presence of endotoxin in P. aeruginosa bacteremia.     

Experimental model of syringomyelia in rabbits

We studied the possibility of reproducing syringomyelia in rabbits by injection of serum from patients with syringomyelia. Clinical signs of syringomyelia and morphological changes in the central nervous system (cavities, dilatation of the cerebrospinal channel, neurodegeneration, gliosis) developed in laboratory animals over 60–120 days. This laboratory model is easily reproducible, stable, and maximally similar to the natural disease, which suggests it for the studies of the pathogenesis and development of new therapeutic methods. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 4, pp. 478–480, April, 2007     

Experimental model of acute ischemia of the retina in rats

We studied the development of retinal ischemia in rat eye after laser coagulation of blood vessels. Typical signs of ischemia manifested in the retina after 24 h: development of stable retinal edema, decrease in the b/a index (ratio of the electroretinogram b and awave amplitudes) to 1–2 units, pronounced disorders in the retinal microcirculation system, leading to ischemia of the inner layers of the retina. The proposed model is convenient for studies of the development of acute retinal ischemia, is easily realized, and reproduces some acute ischemic diseases of the retina. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 145, No. 6, pp. 634–637, June, 2008     

血清miR-16与新生儿败血症患儿心功能障碍及炎症反应的关系

目的探究血清miR-16与新生儿败血症患儿心功能障碍及炎症反应的相关性。方法回顾性分析119例新生儿败血症患儿(败血症组)的临床资料,另选取100例同期住院的普通感染新生儿(对照组)作为对照,评估2组患儿心功能、血清炎症因子及血清miR-16表达水平。根据左室射血分数(LVEF)将败血症组患儿分为心功能障碍组及无心功能障碍组,采用多因素Logistic回归分析血清miR-16表达水平对新生儿败血症患儿发生心功能障碍的影响,采用受试者工作特征(ROC)曲线分析血清miR-16表达水平对新生儿败血症患儿发生心功能障碍的诊断价值,采用Pearson法分析新生儿败血症患儿血清miR-16表达水平与炎症因子及心肌损伤标志分子的相关性。结果败血症组患儿的血清miR-16表达水平显著高于对照组患儿(P<0.001)。心功能障碍组患儿的血清miR-16表达、白细胞介素-6(IL-6)、C反应蛋白(CRP)、心肌肌钙蛋白Ⅰ(cTnⅠ)、乳酸脱氢酶(LDH)、肌酸激酶心肌同工酶(CK-MB)、心脏型脂肪酸结合蛋白(H-FABP)水平及QT离散度、Tie指数均显著高于无心功能障碍组患儿,而LVEF则显著低于无心功能障碍组患儿(P<0.001)。多因素Logistic回归分析显示,血清miR-16表达水平是新生儿败血症患儿发生心功能障碍的独立危险因素(P<0.05)。经ROC曲线分析,采用血清miR-16表达水平诊断新生儿败血症患儿发生心功能障碍的曲线下面积(AUC)为0.901(95%CI0.846~0.956),特异度和灵敏度分别为80.7%和85.5%。经Pearson相关性分析,新生儿败血症患儿的血清miR-16表达水平与IL-6、CRP、cTnⅠ、LDH、CK-MB、H-FABP水平呈显著正相关性(r=0.439、0.341、0.325、0.842、0.683、0.705,P<0.001)。结论新生儿败血症患儿血清miR-16升高与炎症反应有关,检测血清miR-16表达水平对新生儿败血症患儿发生心功能障碍有一定诊断价值。     

Utility of lytic bacteriophage in the treatment of multidrug-resistant Pseudomonas aeruginosa septicemia in mice

Drug resistance is the major cause of increase in morbidity and mortality in neonates. One thousand six hundred forty-seven suspected septicemic neonates were subjected for microbiological analysis over a period of 5 years. Forty-two P. aeruginosa were isolated and the antibiogram revealed that 28 P. aeruginosa were resistant to almost all the common drugs used (multidrug-resistant). The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. As a result, a novel and most effective approaches for treating infection caused by multidrug-resistant bacteria are urgently required. In this context, one intriguing approach is to use bacteriophages (viruses that kill bacteria) in the treatment of infection caused by drug-resistant bacteria. In the present study, the utility of lytic bacteriophages to rescue septicemic mice with multidrug-resistant (MDR) P. aeruginosa infection was evaluated. MDR P. aeruginosa was used to induce septicemia in mice by intraperitoneal (i.p.) injection of 10 7 CFU. The resulting bacteremia was fatal within 48 hrs. The phage strain used in this study had lytic activity against a wide range of clinical isolates of MDR P. aeruginosa. A single i.p. injection of 3 x 10 9 PFU of the phage strain, administered 45 min after the bacterial challenge, was sufficient to rescue 100% of the animals. Even when treatment was delayed to the point where all animals were moribund, approximately 50% of them were rescued by a single injection of this phage preparation. The ability of this phage to rescue septicemic mice was demonstrated to be due to the functional capabilities of the phage and not to a nonspecific immune effect. The rescue of septicemic mice could be affected only by phage strains able to grow in vitro on the bacterial host used to infect the animals and when such strains are heat-inactivated, they lose their ability to rescue the infected mice. Multidrug-resistant bacteria have opened a second window for phage therapy. It would seem timely to begin to look afresh at this approach. A scientific methodology can make phage therapy as a stand-alone therapy for infections that are fully resistant to antibiotics.     

Experimental Rhodotorulosis infection in rats

The low pathogenicity of Rhodotorula spp. is probably related to its reduced ability to grow at 37 °C, an attribute typically enhancing virulence of pathogenic strains. Animal experimentation is a valuable tool to study the pathogenesis of unusual human mycosis, such as Rhodotorula infection. The authors describe the first experimental model of disseminated Rhodotorula infection described in the literature and comment the relevant histopathologic aspects of the infection. Our results showed that the most affected organs by R. mucilaginosa were the lungs, spleen, and especially the liver which presented severe degree of infection. Considering the animals were highly immunocompromised, histopathology of the involved affected organs revealed few epithelioid cells and multinuclear giant cells in association with abundant yeast forms with occasional granuloma formation.     

Deciphering the role of ectosomes in cancer development and progression: focus on the proteome

Ectosomes are small heterogeneous membrane vesicles generated by budding from the plasma membrane in a variety of cell types and, more frequently, in tumor cells. They are shed into the extracellular space and are proposed as a novel form of intracellular communication in which information is transmitted from the originating cell to recipient cells without direct cell-to-cell contact. This review focuses on a single population of extracellular vesicles—ectosomes. We summarize recent studies of tumor-derived ectosomes which examine their biogenesis and protein cargo, and their influence on different aspects of cancer progression. We discuss possible clinical implications involving ectosomes as potential biomarkers, diagnostic tools and treatment targets in oncology. The unique composition of the molecules (cargo) that ectosomes carry, and their functional role, depends largely on the state of their originating cell. Through horizontal transfer of a variety of biologically active molecules (including proteins, lipids and nucleic acids) between donor and recipient cells, tumor-derived ectosomes may play functional roles in oncogenic transformation, tumor progression, invasion, metastasis, angiogenesis promotion, escape from immune surveillance, and drug resistance, thereby facilitating disease progression. The presence of tumor-derived ectosomes in body fluids such as the blood and urine of cancer patients makes them potentially useful prognostic and predictive biomarkers. Tumor-derived ectosomes also offer possible targets for multiple therapeutic strategies.     

Quantitative analysis of the development of experimentally induced post surgical adhesions: a microstereological study

The aim of this study was to quantitatively define the development of post surgical adhesions (PSAs) in a well characterized experimental model and identify possible windows of pathogenesis where pharmaceutical intervention may be most effective. PSAs were induced, in an established rabbit uterine horn model, using standardized reproducible injury, in 17 experimental groups, each with 8 experimental sites and these PSAs were sampled from 30 seconds to 42 days post surgery. Using design based, unbiased stereology, mean volumes of PSAs and associated tissue damage and reaction per experimental site were calculated for each sample time point. PSA development followed the normal pattern of wound healing with surrounding adjacent tissue having a profound influence and interaction. There was a direct relationship between volume of damage (initial and subsequent) and the volume of injury tissue generated. In vivo weak fibrinous PSAs were present from 10 min following injury, with tenacious fibrinous PSAs present from 1 h and onwards. PSA development can be classified into two distinct stages: (i) PSA modelling - occurring during the first 16 h, in which maximum rate of PSA construction is achieved; and (ii) PSA remodelling - from 16 h onwards. Considering this, PSA prevention should ideally be initiated immediately post injury to prevent PSA modelling or, alternatively, during PSA modelling.     

一种在生物医学工程科研中有实用价值的实验设计方法——均匀设计与正交实验设计联用的实验设计方法

提出了一种在生物医学工程研究领域中有实用价值的优化实验设计方法。通过比较均匀设计与正交实验设计各自的特点，提出了将两种实验设计方法联合使用的一种新的实验设计方法，对其理论基础和使用方法及特点进行了阐述，并通过实验证明该方法的有效性。该方法具有均匀设计适用于多因素多水平和实验次数少的特点，回避了均匀设计只能用计算机分析软件才能对数据进行分析的不足，同时保留了正交实验设计应用面广，可以对实验结果进行简单直观地分析的特点，适合于生物医学工程学的科学研究。     

兔子宫壁组织力学特性的实验研究

目的 研究兔子宫壁组织的生物力学特性,并对分娩与未分娩组兔子宫壁力学特性进行比较.方法 以14只新西兰雌性大白兔为研究对象,取其子宫壁组织为拉伸试样,分娩与未分娩分组对照,用WDW4100微机控制电子万能实验机进行拉伸实验,测定其极限强度、应力应变关系;蠕变实验和应力松弛实验测定其黏弹性特征.结果 兔子宫壁组织表现出明显的黏弹性特征,应力应变呈指数关系;分娩组的平均极限应力为0.119MPa,未分娩组的平均极限应力为0.444MPa;分娩组的蠕变和松弛实验均明显比未分娩组低.结论 分娩与未分娩的兔子宫壁组织生物力学特性有明显的差别,对临床上研究人类子宫壁组织有一定的参考价值,有助于妇产科学的发展.     

不同种鼠对实验脑型疟发生的影响研究

目的比较昆明小鼠和C57BL/6小鼠作为种鼠对实验脑型疟模型的影响。方法分别以伯氏疟原虫ANKA株感染C57BL/6小鼠和昆明小鼠作为传代用种鼠,当种鼠原虫率为5%～15%时接种子代C57BL/6小鼠,观察两组小鼠原虫率、脑型疟发生率以及死亡率。同时,通过脑组织切片和脑部淋巴细胞的流式检测,观察两组发生脑型疟小鼠的脑部微血管中感染疟原虫红细胞和CD8＋T细胞的粘附情况,另外,通过感染CD8＋TKO小鼠,证实CD8＋T细胞在两组小鼠发生脑型疟中的作用。结果用昆明小鼠作为种鼠的实验组的原虫率和脑型疟发生率均明显高于用C57BL/6小鼠作为种鼠的实验组,发生脑型疟小鼠的脑部组织切片发现,脑部微血管可见明显的感染疟原虫红细胞的粘附和CD8＋T淋巴细胞浸润;而用昆明小鼠作为种鼠感染CD8＋T细胞缺失的C57BL/6小鼠并不能诱导实验脑型疟的发生。结论与C57BL/6小鼠相比,昆明小鼠作为种鼠的实验组的脑型疟发病率更高,而且感染疟原虫红细胞和CD8＋T细胞在脑部微血管内的粘附也是该脑型疟发生的主要因素,因此,更适合用于实验脑型疟模型的建立及其机制的探讨。     

Experimental liver metastasis: Standards for local cell implantation to study isolated tumor growth in mice

Experimental hepatic metastasis of colorectal tumors is frequently studied by local intrahepatic tumor cell implantation. However, although a variety of factors of the implantation procedure may markedly influence tumor growth characteristics, standards are not defined yet. Herein, we studied the effect of different modes of cell implantation on tumor growth and angiogenesis by in vivo fluorescence microscopy and histology seven days after grafting colorectal CT26.WT tumor cells into the left liver lobe of syngeneic BALB/c mice. We demonstrate that (i) radial growth of cells implanted within the central area of the lobe is inhibited by a regularly observed fissura which crosses at midline the surface of the lobe; (ii) cells suspended during implantation in RPMI show an uncontrolled overwhelming growth 40-fold of those suspended in PBS; (iii) cell implantation in 100 μl and 20 μl suspension medium is significantly more complicated by rupture of the liver capsule, uncontrolled intraparenchymal cell spread and recoil of the cells through the injection canal compared to cells suspended in 10 μl; (iv) the frequency of metastasis within the injection canal and at the puncture site is significantly reduced using 32G compared to 27G or 29G needles; (v) occlusion of the puncture site by acrylic glue or electric coagulation completely abolishes peritoneal tumor spread compared to no treatment or gentle compression by cotton gauze. We conclude that a standardized growth of isolated metastases is best achieved by implanting CT26.WT cells in a 10 μ l PBS blister subcapsularly into the paramedian area of the lower surface of the left liver lobe, using a 32-gauge needle and closing the puncture site with acrylic glue.