Fragmentation of purified mammalian DNA molecules by ultrasound below human therapeutic doses

Summary Because of the increasing medical use of ultrasound, especially in obstetrical diagnosis, it has become important to check its genetic harmlessness. Purified calf thymus DNA in solution was exposed to both therapeutic and obstetrical diagnostic doses of ultrasound. Intensities lower than those used in therapy have a drastic effect on purified DNA in solution, although intensities used in obstetrical diagnosis caused no visible effect.     

颈项透明层厚度超声联合无创DNA对孕妇胎儿染色体非整倍体异常诊断效能的影响

摘要 目的：探讨颈项透明层(nuchal translucency,NT)厚度超声联合无创DNA对孕妇胎儿染色体非整倍体异常诊断效能的影响。方法：2018年7月到2020年4月选择在本院进行产前筛查的孕妇120例,所有孕妇都给予NT厚度超声联合无创DNA检查,采用羊水穿刺分析检测结果为阳性的胎儿情况。结果：120例胎儿的NT厚度为0.8~10 mm,平均厚度为1.57±0.41 mm;不同孕妇年龄的NT厚度对比差异无统计学意义(P>0.05)。以羊水穿刺检测结果为金标准,120例胎儿中检出染色体非整倍体异常7例,NT超声检出12例,无创DNA检出13例,联合检出14例。NT超声、无创DNA与联合诊断的染色体非整倍体异常敏感性为57.1%、85.7%和100.0%,特异性为92.9%、93.8%和93.8%。检测结果为阳性的14例胎儿中,还包括3例淋巴水囊瘤,2例单脐动脉伴胎儿宫内发育迟缓,1例胎儿双肾畸形,1例胎儿并腿畸形。结论：颈项透明层厚度超声联合无创DNA在孕妇胎儿染色体非整倍体异常中的诊断具有操作简便、无创伤等特点,诊断敏感性与特异性都比较高,可对临床医生遗传咨询有一定的参考价值。     

Reactive oxygen species and DNA damage after ultrasound exposure

The aim of this work was to detect the formation of hydrogen peroxide and hydroxyl radicals after ultrasound (US) exposure and test the hypothesis that reactive oxygen species induced by ultrasound can contribute to DNA damage. Formation of reactive oxygen species was observed in incubated medium after sonication with 1 MHz continuous ultrasound at the intensities of 0.61-2.44 W/cm2. Free radicals and hydrogen peroxide produced by ultrasound exposure of cells can lead to DNA damage. Comet assay was used to assess the effect of ultrasound on the level of nuclear DNA damage. The nucleated erythrocytes from fish were exposed in vitro to ultrasound at the same intensities and frequency. It was noticed that ultrasound in all used intensities induced DNA damage. The effect was not eliminated by the addition of catalase, which indicates that DNA damage was not caused by hydrogen peroxide only. The results showed that the DNA damage can be repair and this mechanism was the most effective after 30 and 60 min after sonication. Furthermore, the ultrasound-induced DNA damage in the presence of sonosensitizer (Zn- and AlCl-phthalocyanine) was studied. It was noticed that phthalocyaniens (Pcs) alone or with ultrasound did not induce significant changes in the level of DNA damage.     

The ultrasonic degradation of biological macromolecules under conditions of stable cavitation. I. Theory,methods, and application to deoxyribonucleic acid

Solutions of calf thymus DNA have been degraded in the presence of vibrating air bubbles in ultrasonic fields of low power which would not normally induce ultrasonic cavitation. The DNA was degraded to a limiting intrinsic viscosity, after which further irradiation by ultrasound had little or no effect. This limiting intrinsic viscosity decreased with increase in the ultrasonic intensity. Previously developed theories have-been adapted to calculate the maximum velocity gradient associated with the streaming of the solution around such vibrating air bubbles. The tensile force which is induced and which acts on the DNA has been calculated on the basis of current theories of degradation by hydrodynamic shear. These calculations indicate that the degradation of the DNA by ultrasound under conditions of “stable cavitation” is mainly the result of the shearing forces engendered in the solution around the oscillating bubbles.     

The specific cleavage of DNA with ultrasound

Cleavages of double-stranded DNA fragments of known base pair sequence upon ultrasound irradiation at 22 and 44 kHz were studied by gel electrophoresis. The cleavage rate is found to be strongly dependent on the DNA fragment length, pH, temperature and ionic strength of the solution under study. The cleavage of double-stranded DNA occurs predominantly at sites containing alternating 5'-CpG-3' sequences. The breakage of phosphatediester bond takes place between C and G in such a way that phosphate group at the 5'-end of the guanine residue remain intact. The cleavage rate at a given DNA site is found to depend on base pair sequences at adjacent sites. Distinctly different cleavage patterns are observed when free DNA and DNA complexes with cys-diammine-Pt-bridged bis-netropsin were irradiated by ultrasound. The observed effect can be attributed to local DNA conformation changes induced upon complex formation between ligand and DNA.     

A morphometric analysis of the fetal craniofacies by ultrasound: fetal cephalometry

We present here a set of 24 standardized linear measurements that describe the growth of different craniofacial structures in the normal fetus from 16 to 36 weeks of gestation. These measurements were taken from 89 pregnant women, who had from 1 to 3 ultrasonographic evaluations during the pregnancy (16, 26, and 36 weeks of gestation). All the values presented here were obtained using the technique described by Escobar et al. The mean and standard deviation was calculated for each measurement and was used to estimate the normal growth pattern of each variable. Approximate confidence intervals for the mean of each variable were constructed for use in identifying unusually low or high values. The confidence intervals are available in graphic form by request. These data will not only contribute to an understanding of fetal craniofacial growth and development in utero, but in addition, it will help to make the diagnoses of mild craniofacial anomalies that would not be detected by the routine ultrasonographic examination. We suggest that this procedure should be included if not in all routine obstetrical ultrasound evaluations, then at least in the more extensive level II obstetrical ultrasound.     

Damage in DNA irradiated with 1.2 MHz ultrasound and its effect on template activity of DNA for RNA synthesis

When aqueous DNA solution was irradiated with 1.2 MHz continuous ultrasound in the presence of cysteamine, the number of ultrasound-induced double-strand breaks of DNA was not influenced, but the number of ultrasound-induced single-strand breaks of DNA was reduced to about one-fifth that of the irradiated control. When the effect of cysteamine on the template activity of the ultrasound-irradiated DNA was investigated, the cysteamine was found to exert a leveling effect on the linear decrease of the template activity against ultrasonic intensity. Since cysteamine was known as an effective radical scavenger, the results of the experiment were regarded to suggest that (1) the double-strand breaks were exclusively induced by the mechanical effect of ultrasound, (2) the majority of single-strand breaks were produced by water radicals arising from cavitation, (3) the initial part in the decrease of the template activity was due to the double-strand breaks arising from mechanical effect, and (4) the further decrease of the template activity depended mainly on the single-strand breaks arising from water radicals.     

Sister-chromatid exchanges in mouse embryos after exposure to ultrasound in utero

Mouse embryos at 2 stages of development were exposed to ultrasound. The bone-marrow cells of the mother, the whole embryo, and the embryonic liver cells were analyzed. There was no consistent increase of sister-chromatid exchanges. Furthermore, the thermal effect of ultrasound did not appear to influence the frequency. Thus, ultrasound doses much higher than those used in clinical diagnosis do not induce cytogenetic damage as assayed by sister-chromatid exchanges.     

Capacities of transabdominal ultrasound study in the diagnosis of polyps of the stomach and colon

The data obtained from studies of 84 patients with polyps of the stomach and colonic were used to consider the capacities of transabdominal and transrectal ultrasound studies and their diagnostic efficiency in the diagnosis of polyps of the stomach and colon. The ultrasound semiotics of polyps of the gastric and colon was described. A place of transabdominal ultrasound sonography (US) in the algorithm of radiation and endoscopic studies was established. This investigation led to the conclusion that transabdominal US, along with indirect diagnosis, permits solution of number of fundamental problems facing prior to polypectomy--these are primarily to define the nature of a detected polyp (epithelial and non-epithelial), based on an analysis of the laminar structure of the wall of an organ at the polyp base, a possible polyp malignancy and the degree of invasion into the depths of the gastric wall, as well as to detect a feeding vessel (in the CDC mode) and to predict the likelihood of possible complications. It is advisable to use transabdominal US in a complex of diagnostic techniques for polyps of the stomach and colon.     

Uterine evaluation and gestation diagnosis in owl monkey (Aotus azarai infulatus) using the B mode ultrasound

BACKGROUND: Gynecological and obstetrical ultrasonography has become an indispensable tool in the routine management, health evaluation and research on captive non-human primates. METHODS: Ultrasound was used to evaluate the uterus and estimate the gestation of owl monkeys. Twelve couples were selected, where five were primiparous and seven multiparous females from the National Primate Center reproductive colony, Ananindeua-PA, Brazil. The procedures were carried out using the GE Logiq 100 MP, equipped with a 7.5 MHz linear probe. RESULTS: The females showed a simple uterus, of elongated shape, regular outline and homogeneous echogenic texture. In the uterine measurements craniocaudal diameter, dorsoventral diameter and uterine volume (UV), significant differences were identified (P < 0.05) between ultrasound examinations of primiparous and multiparous females. The UV showed a positive correlation with the number of births. The gestational sac and the embryonic echo were visible between 28 and 38 days after mating. Between 48 and 68 days after mating, embryonic death was identified in all the gestations. CONCLUSIONS: The chemical (use of tranquilizers) and husbandry factors (capture stress) may be related to the prenatal death. The establishing methods of conditioning the female to the ultrasonographic exam may offer a solution to this problem.     

超声弹性成像与超声造影对肝肿瘤的诊断效果对比

目的:分析超声弹性成像与超声造影对肝肿瘤的诊断效果。方法:收集我院2015年3月至2016年3月收治的肝肿瘤患者76例,术前均行超声弹性成像和超声造影检查,比较超声弹性成像和超声造影与病理诊断(黄金标准)的结果。结果:超声弹性成像与病理检查结果比较无统计学差异(P0.05);超声造影与病理检查结果无统计学差异(P0.05);超声弹性成像和超声造影的敏感性、特异性、准确性无统计学差异(P0.05)。结论:超声弹性成像、超声造影对肝肿瘤诊断中均有重要价值,建议二者联合检测,提高肝肿瘤检出准确率。     

A role and a place of ultrasound diagnosis of acute ileus

The main purpose of the authors is to present their view of a place of present-day ultrasonography in the diagnosis of acute small and large intestinal obstruction. A comparatively sizable material covering 218 verified cases of acute ileus, including 77 patients with large intestinal obstruction and 141 patients with impaired passage of the intestinal contents along the small bowel was used to outline the aspects of ultrasound techniques and the symptomatology of ileus, by differentiating its some types. Along with the general assessment of the methodological and semiotic aspects of ultrasound diagnosis of acute uleus, the authors emphasizes a role of sonography in the detection of large intestinal obstruction by outlining their modified procedure of ultrasound irrigoscopy. For greater objectivization of their positive assessment of the place of ultrasound in the diagnosis of acute ileus and large intestinal obstruction, the authors comparatively studied X-ray and ultrasound studies to reveal this pathology. In addition to their purely personal assessment of a role of ultrasound in the diagnosis of large intestinal obstruction, the lecture also shows its authors' opinion as to the organizational issues associated with the necessity of correcting the existing diagnostic algorithm to detect large intestinal obstruction.     

Potentialities of transabdominal ultrasound study in the diagnosis of gastric peptic ulcer

The results of examination in 44 patients with gastric peptic ulcer were used to consider the potentialities of a transabdominal ultrasound study in the diagnosis and monitoring of gastric ulcerations. The ultrasound semiotics of gastric ulcers is described in the paper. A role of transabdominal ultrasound study in the algorithm of radiation and instrumental studies of gastric ulcer is defined. The inclusion of this study into the algorithm of diagnosis and monitoring of gastric peptic ulcer will make it possible not only to diagnose gastric ulcerations better, but to follow up their cicatrization. It is expedient to include a transabdominal ultrasound study as one of the diagnostic techniques for gastric peptic ulcer.     

Sonography and sociality: obstetrical ultrasound imaging in urban Vietnam

This article is about new reproductive technologies, maternal anxieties, and existential uncertainties. It explores the question of why pregnant women in Vietnam's capital, Hanoi, have become avid consumers of obstetrical ultrasound scanning even while expressing profound doubts regarding the reliability and safety of this new technology of pregnancy. Through a phenomenological analysis of the social production of women's sense of reproductive risks and uncertainties, the article shows how Hanoian women's paradoxical stances toward ultrasound imaging can be explained through a consideration of embodied and historically generated experiences within everyday local worlds. The article argues that the "scientific stories" of fetal well-being and normality that are produced through ultrasonography are challenged by vivid and continual exchanges in everyday lives of stories of the inherent uncertainties of existence in general and of human reproduction in particular.     

Prenatal diagnosis of limb and digital abnormalities. Evaluation of the activity of the Port Royal University Clinic from 1979 to 1983. Apropos of 30 cases

Since 1979, thanks to high level ultrasonography systematic ultrasonic examinations between the 18th and the 22nd week of pregnancy have permitted to prediagnose limb and extremity abnormalities. Embryoscopy and foetoscopy can be used as additional techniques. This paper reports the activity results of the Port Royal Maternity hospital, between 1979 and 1983. In this hospital's Prenatal diagnosis Center, ultrasonographists, obstetricians, geneticists, surgeons, pediatricians and foetopathologists work together fruitfully. 16 limb abnormalities and 14 extremity abnormalities were detected there. We describe the circumstances of their detection, the diagnostic methods used, and the obstetrical attitude chosen.     

Different effects of polylysine and polyarginine on the transition to a condensed state of DNA in polyethyleneglycol/salt solution.

Circular dichroism spectroscopy has been used to investigate the influence of polylysine and polyarginine on the transition to a condensed state of DNA brought about by high concentrations of polyethyleneglycol and salt. From the dependence on DNA concentration of the CD signals, the anomalous CD of free DNA in polyethyleneglycol/salt solution was attributed to the intermolecular association of DNA molecules. The CD spectral changes in polyethyleneglycol/salt solution of the DNA - polylysine complex were indistinguishable from those of free DNA while the DNA-polyarginine complex suffered much smaller spectral changes as compared with free DNA, at low DNA concentrations where time-independent CD spectra were observed in polyethyleneglycol/salt solution for both the complexed and free DNA. The repression of the spectral change by the latter complex was more remarkable at higher ratios of polyarginine to DNA. The facts indicate that, whereas polylysine binding has little influence on the intermolecular structural transition of double-stranded DNA into a compact molecular configuration in polyethyleneglycol/salt solution, polyarginine binding has an effect of inhibiting the transition.     

Effects of ultrasound on DNA and RNA synthesis in preimplantation mouse embryos.

Ultrasound is used extensively to monitor the growth of ovarian follicles in in vitro fertilization and embryo transfer (IVF-ET) programs, as well as to follow the progress of early pregnancy. There have been scattered reports in the literature that exposure to ultrasound may have an adverse effect on reproduction in the rat (Bologne et al: CR Soc Biol 177:381-387, 1983; Demoulin et al: Ann NY Acad Sci 442:146-152, 1985), and also in humans (Demoulin et al: Ann NY Acad Sci 442: 146-152, 1985). We report here that diagnostic levels of pulsed ultrasound did not affect either the number of embryos produced, or the ability to incorporate labelled precursors into DNA and RNA, respectively. Measurements of temperature elevation of ovaries exposed to ultrasound showed that neither controls nor experimental tissue exhibited temperature elevation greater than 1 degree C.     

Ultrasound Mediated Delivery of Compounds into Petunia Protoplasts and Cells

The effects of ultrasound on uptake of foreign substance by Petunia protoplasts were studied using calceln (3, 6-dihydroxy-2,4- bis-[N, N-di (carboxymethyl)—aminoethyl fluoran] and DNA. Neither the protoplasts nor cells took up the calcein, but treatment with ultrasound facilitated the uptake. Pronounced stimulation of uptake was observed with protoplasts but only moderate stimulation was observed with the cells. The ultrasound uptake was dependent on sound frequency, temperature and duration of treatment. Uptake increased with treatment time but prolong treatment caused the rupture of protoplasts. Ultrasound also facilitated uptake of DNA by cells of Petunia. In this study the plasmid pBI 121.2 carrying a reporter, β-glucuronidase (GUS)’gene was used. Transient expression of this gene was an indicator of DNA uptake. Survived protoplasts and cells subjected to ultrasound treatment divided and formed microcalli in agarose medium.     

Spin trapping of precursors of thymine damage in X-irradiated DNA

A spin-trapping method combined with ESR spectroscopy was utilized to obtain evidence for the presence of precursor radicals leading to damage in X-irradiated DNA. Two technical improvements were introduced to the conventional spin-trapping method to make possible its application to large molecules such as DNA: prior to X irradiation, sonolysis of aqueous DNA solution by 19.5-kHz ultrasound was made to get a highly concentrated DNA solution and to lower the viscosity of the solution; after precursor radicals in X-irradiated DNA were trapped by a spin-trapping reagent, the DNA was digested to oligonucleotides by DNase I to get an ESR spectrum with a well-resolved hyperfine structure. Thus, it was recognized that the ESR spectrum obtained after X irradiation of the aqueous solution containing DNA and the nitroso spin-trapping reagent 2-methyl-2-nitrosopropane consisted of at least three sets of signals in the DNA. Identification of free radicals was made by comparing the spectrum with that of thymidine, which was precisely examined by a spin-trapping method combining two kinds of spin traps (nitroso and nitrone compounds) with liquid chromatography. As a result, all the signals were identified as the spin adducts of radicals produced at the thymine base moiety of DNA. The 5-hydroxy-5,6-dihydrothymin-6-yl radical was identified as a precursor of 5,6-dihydroxy-5,6-dihydrothymine (thymine glycol), the 6-hydroxy-5,6-dihydrothymin-5-yl radical as a precursor of 6-hydroxy-5,6-dihydrothymine, and the 5-methyleneuracil radical as a precursor of 5-(hydroxymethyl) uracil.     

NMR studies of conformational states and dynamics of DNA

The application of high resolution NMR techniques to the investigation of DNA double helices in solution is currently in a rapid state of change as a result of advances in three different fields. First, new methods (cloning, enzymatic degradation, sonication, and chemical synthesis) have been developed for producing large quantities of short DNA suitable for NMR studies. Second, there have been major advances in the field of NMR in terms of the introduction of new pulse techniques and improvements in instrumentation. Finally, as a result of recent X-ray diffraction studies on short DNA helices and the discovery of left-handed Z-DNA there is heightened interest in the study of DNA structures in solution and the effect of sequence on structure. In the present review, we discuss the way in which NMR techniques have been used to probe various aspects of the DNA properties, including base pairing structure, dynamics of breathing, effect of sequence on DNA structure, internal molecular motions, the effect of environment on the DNA, and the interaction of DNA with small ligands.