Potentialities of lymphography using chromethiotrast, a new x-ray contrast medium]

A study was made of the potentialities of lymphography using a new radiopaque medium chromethiotrast (a solution of harmless fat-soluble anthraquinone dyes fixed with ethiotrast). The agent is intended for combined x-ray and visual investigation of the lymphatic system. Lymphograms of 76 patients (with Hodgkin's disease, prostatic cancer, cancer of the female organs, breast, bladder, rectal cancer, and secondary limb lymphedema) were analyzed. Chromethiotrast is easily administered in the lymphatic bed ensuring a good contrast density of the lymphatic vessels permitting the detection of their structure. Chromethiotrast is quickly discharged from the lymphatic system, causing no marked side-effects provided all precautions necessary for the administration of iodobutyric radiopaque media, are taken.     

Functional digital subtraction sialography in the diagnosis of salivary gland diseases]

Functional digital subtraction sialography with a water soluble radiopaque agent (verografin) made it possible to investigate the structure and functional changes in the salivary glands of 26 patients with a minimum injury of the glands. The method permitted a decrease in a dose of the agent 4 times as compared to routine sialography; the consumption of x-ray film was decreased 5-fold. Digital processing of images helped avoid superimposing of the cranial bone components, improving the quality of images of the salivary glands. The method is indispensable during differential diagnosis, especially at early stages of diseases of the salivary glands.     

Use of a radiopaque localizer grid to reduce radiation exposure

Background

Minimally invasive spine surgery requires placement of the skin incision at an ideal location in the patient's back by the surgeon. However, numerous fluoroscopic x-ray images are sometimes required to find the site of entry, thereby exposing patients and Operating Room personnel to additional radiation. To minimize this exposure, a radiopaque localizer grid was devised to increase planning efficiency and reduce radiation exposure.

Results

The radiopaque localizer grid was utilized to plan the point of entry for minimally invasive spine surgery. Use of the grid allowed the surgeon to accurately pinpoint the ideal entry point for the procedure with just one or two fluoroscopic X-ray images.

Conclusions

The reusable localizer grid is a simple and practical device that may be utilized to more efficiently plan an entry site on the skin, thus reducing radiation exposure. This device or a modified version may be utilized for any procedure involving the spine.     

The susceptibility of pure tubulin to high magnetic fields: a magnetic birefringence and x-ray fiber diffraction study.

The orientational behavior of microtubules assembled in strong magnetic fields has been studied. It is shown that when microtubules are assembled in a magnetic field, they align with their long axis parallel to the magnetic field. The effect of several parameters known to affect the microtubule assembly are investigated with respect to their effect on the final degree of alignment. Aligned samples of hydrated microtubules suitable for low-resolution x-ray fiber diffraction experiments have been produced, and the results obtained from the fiber diffraction experiments have been compared with the magnetic birefringence experiments. Comparisons with earlier fiber diffraction work and small-angle x-ray solution scattering experiments have been made.     

Calcified gallstone in a 3 year-old boy: a case report

ABSTRACT: BACKGROUND: Gallstones are relatively rare in children. At-risk populations include patients suffering from hemolysis syndromes. Regardless of etiology, these patients usually will present with postprandial abdominal pain, and ultrasonography is the mainstay of diagnosis. However, some gallstones are radiopaque and can be visualized on plain abdominal radiography. CASE PRESENTATION: We present the uncommon but classic plain x-ray finding of a calcified gallstone in a 3 year-old Hispanic boy. He was treated with elective laparoscopic cholecystectomy. CONCLUSIONS: Cholelithiasis is rare in children, and calcified stones that will appear on plain abdominal x-rays are even rarer. If symptomatic, cholecystectomy by a pediatric surgeon is the treatment of choice. We discuss some of the recent developments in treatment of this condition in this patient population.     

Protein structure determination in solution by NMR spectroscopy

The introduction of nuclear magnetic resonance (NMR) spectroscopy as a second method for protein structure determination at atomic resolution, in addition to x-ray diffraction in single crystals, has already led to a significant increase in the number of known protein structures. The NMR method provides data that are in many ways complementary to those obtained from x-ray crystallography and thus promises to widen our view of protein molecules, giving a clearer insight into the relation between structure and function.     

The effect of intracoronary injections of x-ray contrast media on cardiac rhythm and conductivity during different variations of myocardial blood supply]

A study of the correlation between electrophysiologic effects of intracoronary injections of radiopaque agents and anatomical features of blood supply of cardiac conduction was carried out in 60 patients with intact coronary arteries. Coronary angiography was performed in all the patients. Disorders in cardiac conduction and repolarization in the myocardium were observed in intracoronary injection of radiopaque agents, which was accompanied by the development of S-A bradycardia. A bradyarrhythmic reaction type depends on prevalence of the left or right coronary artery in the atrial blood supply and cardiac conduction. The bradyarrhythmic effect was more pronounced in injection of a radiopaque agent in the right artery than in the left one.     

Body measurements correlation and x-ray imaging of three Hystrix javanica fetuses in different fetal development stages

Hystrix javanica is endemic species in Indonesia. Study about fetal development of Hystrix javanica are very rare because of sample limitation. This study was carried out to describe the morphometrics and x-ray analysis of three fetuses in different stage to give basic information about fetal development of Hystrix javanica. Three fetus samples fixed in Bouin’s solution was used in this study. Observation was carried out to identify the characteristic of three fetus samples. This included the pattern of hair, body measurements, body volume, and body weight. X-ray analysis was carried out to know the ossification process in the fetal development. Statistical analysis was carried out using Microsoft 365® Excel program software. Three fetus samples had different specific hair pattern, that was hairless, smooth hairs, and smooth hairs with dense-non dense pattern. Body volume of 1^st, 2^nd, and 3^rd fetus were 23mL, 90mL, and 170mL, respectively. Body weight of 1^st, 2^nd, and 3^rd fetus were 19.5g, 79.22g, and 153.18g, respectively. Pearson’s correlation analysis shown strong relationship between total body length, front body length, back body length, horizontal body diameter, vertical body diameter, head length, and head diameter against body volume and body weight of three fetuses. Significant positive correlation was shown between horizontal body diameter, vertical body diameter, and head diameter against body volume and body length with P value < 0.05. Faint radiopaque images showed in the 2^nd fetus sample and strong radiopaque images showed in the 3^rd fetus sample. Radiopaque images were identified in the teeth, cranium, vertebrae, and extremities bones. In this study we concluded that there was a specific hair pattern in different fetal stage. All body measurements have positive correlation with body volume and body weight and x-ray analysis shown that the ossification of the bone was started to happen while the smooth hair was growth.     

Re-analysis of magic angle spinning nuclear magnetic resonance determination of interlamellar waters in lipid bilayer dispersions.

A recent method to obtain the number of water molecules of hydration of multilamellar lipid vesicles using magic angle spinning nuclear magnetic resonance has been re-examined. The previous interpretation divided the water into bulk and interlamellar water and ignored water in defects (lakes) that are intrinsic to multilamellar lipid vesicles; the result was inconsistent with x-ray results for the lipid DOPC. The new interpretation takes advantage of the reduction of lake water with increased spinning and it uses osmotic pressure measurements to determine the loss of interlamellar water. The new result for DOPC from magic angle spinning is consistent with x-ray results.     

Synthesis and characterization of radiopaque iodine-containing degradable PVA hydrogels

Poly (vinyl alcohol) (PVA) hydrogels are highly attractive for biomedical applications, especially for controlled release of drugs and proteins. Recently, degradable PVA hydrogels have been described, having the advantage that the material disappears over time from the implantation site. Herein, we report the synthesis of radiopaque degradable PVA, which gives a further advantage that the position of the hydrogel can precisely be determined by X-ray fluoroscopy. Radiopacity has been introduced by replacing 0.5% of the pendent alcohol groups on the PVA with 4-iodobenzoylchloride. This level of substitution rendered the polymer adequately radiopaque. The subsequent modification of 0.8% of the pendent hydroxyl groups with an ester acrylate functional group allowed for cross-linking of the macromers. The radiopaque hydrogels degraded over a time span of 140 days. Rheology data suggested that the macromer solutions were appropriate for injection.     

A study of the in vitro and in vivo interaction of barium sulphate particles with gastro-intestinal mucus.

The in vivo interaction of various radiopaques with mucus was investigated by a determination of the pH-mobility curves of the treated particles. It was found that mucus covered the radiopaque particles both in vivo and in vitro. This interaction was not affected by the nature of the radiopaque or by the state of the mucous membrane. The changed state of the mucus was modified by the diet of the rat from which it was derived. The results are discussed with reference to the technique used in the administration of radiopaques.     

Strategies for the uses of lanthanide NMR shift probes in the determination of protein structure in solutio. Application to the EF calcium binding site of carp parvalbumin.

The homologous sequences observed for many calcium binding proteins such as parvalbumin, troponin C, the myosin light chains, and calmodulin has lead to the hypothesis that these proteins have homologous structures at the level of their calcium binding sites. This paper discusses the development of a nuclear magnetic resonance (NMR) technique which will enable us to test this structural hypothesis in solution. The technique involves the substitution of a paramagnetic lanthanide ion for the calcium ion which results in lanthanide induced shifts and broadening in the 1H NMR spectrum of the protein. These shifts are sensitive monitors of the precise geometrical orientation of each proton nucleus relative to the metal. The values of several parameters in the equation relating the NMR shifts to the structure are however known as priori. We have attempted to determine these parameters, the orientation and principal elements of the magnetic susceptibility tensor of the protein bound metal, by studying the lanthanide induced shifts for the protein parvalbumin whose structure has been determined by x-ray crystallographic techniques. The interaction of the lanthanide ytterbium with parvalbumin results in high resolution NMR spectra exhibiting a series of resonances with shifts spread over the range 32 to -19 ppm. The orientation and principal elements of the ytterbium magnetic susceptibility tensor have been determined using three assigned NMR resonances, the His-26 C2 and C4 protons and the amino terminal acetyl protons, and seven methyl groups; all with known geometry relative to the EF calcium binding site. The elucidation of these parameters has allowed us to compare the observed spectrum of the nuclei surrounding the EF calcium binding site of parvalbumin with that calculated from the x-ray structure. A significant number of the calculated shifts are larger than any of the observed shifts. We feel that a refinement of the x-ray based proton coordinates will be possible utilizing the geometric information contained in the lanthanide shifted NMR spectrum.     

Prospects for use of iodine-free radiopaques for cholecystocholangiography

By using the compounds tantalum and lanthanum, a new radiopaque substance (ROS) was synthesized at the Institute for Chemistry of Solids, Urals Branch of the Russian Academy of Sciences. Experiments on laboratory animals provided evidence that there was no acute or chronic toxicity of helium-based lanthanum orthotantalate. The specific radiopaque properties of the agent versus iodine- and barium-containing ROSs were studied in in vitro and in vivo experiments. The radiodiagnostic properties and locally irritant effect of the test ROS versus iodine-containing agents were evaluated in dogs at cholecystocholangiography.     

The possible use of new technologies for treating some diseases at the atomic-molecular level

Transitions from the normal to the pathological state can be studied at the atomic-molecular level simultaneously with treatment with electron spin resonance electrodialysis and nuclear magnetic resonance electrodialysis under the conditions of biological specimen cultivation, with simultaneous recording of microcalorimetry parameters. It is reasonable to test the possibility of application of some diagnostic recording devices as therapeutic agents. Modeling of the conditions of x-ray tomography permits these devices to also be used to determine the safety of x-ray tomography at the atomic-molecular level. This work shows the possibility of studying early rearrangements and states at the premorbid stage.     

Neutron and x-ray scatter studies of the histone octamer and amino and carboxyl domain trimmed octamers

The structure of the nucleosome has been under intense investigation using neutron crystallography, x-ray crystallography, and neutron solution scattering. However the dimension of the histone octamer inside the nucleosome is still a subject of controversy. The radius of gyration (Rg) of the octamer obtained from solution neutron scattering of core particles at 63% 2H2O, 37% 1H2O is 33 A, and x-ray crystallography study of isolated histone octamer gives a Rg of 32.5 A, while the reported values using x-ray crystallography of core particles from two individual studies are 29.7 and 30.4 A, respectively. We report here studies of isolated histone octamer and trypsin-limited digested octamer using both neutron solution scattering and small angle x-ray scattering. The Rg of the octamer obtained is 33 A, whereas that of the trimmed octamer is 29.8 A, similar to the structure obtained from the crystals of the core particles. The N-terminal domains of the core histones in the octamer have been shown by high resolution nuclear magnetic resonance (Schroth, G.P., Yau, P., Imai, B.S., Gatewood, J.M., and Bradbury, E.M. (1990) FEBS Lett. 268, 117-120) to be mobile and flexible; it is likely that these regions are disordered and "not seen" by x-ray crystallography.     

Injectable polymeric microspheres with X-ray visibility. Preparation,properties, and potential utility as new traceable bulking agents

The copolymer of methyl methacrylate (MMA) and 2-[2',3',5'-triiodobenzoyl]oxoethyl methacrylate (1), ratio 3:1 (mass:mass), was prepared via a free-radical polymerization in bulk. The copolymer (M(w) = 97.8 kD and M(n) = 41.5 kD) was dissolved in chloroform and subsequently transformed into beads with a diameter in the micrometer range, using a solvent evaporation technique. The resulting microbeads were characterized by different techniques, including NMR spectroscopy, differential scanning calorimetry, gel permeation chromatography, and scanning electron microscopy. The latter technique was used as the basis for statistical analysis of the bead size. Typically, an average diameter of 96 microm and a standard deviation of 21 microm were obtained. The beads were also subjected to some preliminary tests regarding cytotoxicity. The copolymer of MMA and 1 contains covalently bound iodine. Therefore, the material is intrinsically radiopaque, i.e., capable of absorbing X-radiation while no contrast additive is needed. Our interest in these microspheres stems primarily from their possible utility as injectable and afterward traceable (radiopaque) bulking agents, e.g., for use in urology for the treatment of female stress incontinence due to sphincter deficiency. As a first test into this direction, a sample of the microbeads was mixed with ethylene glycol, and the resulting suspension was studied with respect to injectability and radiopacity. The results suggest that the radiopaque microbeads may provide access to improved bulking agents. Further modification of the surface may be necessary in order to suppress the migratory aptitude of the radiopaque polymeric microspheres in vivo.     

The use of cerebral ventriculography for verification of intracerebroventricular cannula placement in the live rat

A technique using cerebral ventriculography for verification of intracerebroventricular cannula placement in the live rat is described. A radiopaque contrast medium, diatrizoate meglumine, was injected into the right lateral ventricle through a cannula stereotaxically implanted into the brain. Radiographic visualization of the radiopaque contrast material in the lateral ventricle and the subarachnoid space verified cannula placement. Transient muscular spasms were observed in about 38% of the injected rats but no lasting changes were observed in the behavior or appearance of these rats.     

Comparative characteristics of radiation imaging methods in the diagnosis of sacroiliitis

Patients with sacroiliac joint, injuries, ankylosing spondyloarthritis, or spondyloarthropathy of various genesis were examined. Pelvis x-ray, spiral computed tomography (CT), and magnetic resonance imaging (MRI) were performed. MRI was found to have advantages in the detection and evaluation of the pattern of detectable bone changes. It is inexpedient to use traditional x-ray study and CT for the detection of edematous-infiltrative changes in both osseous and fibrous and soft tissue elements of the joint since the sensitivity of these techniques is insufficient to detect. To analyze detectable changes, it is expedient to use a unified MRI protocol that involves the characteristics of osseous, fibrous, and soft tissue structures of the joint.     

Are Human Peripheral Nerves Sensitive to X-Ray Imaging?

Diagnostic imaging techniques play an important role in assessing the exact location, cause, and extent of a nerve lesion, thus allowing clinicians to diagnose and manage more effectively a variety of pathological conditions, such as entrapment syndromes, traumatic injuries, and space-occupying lesions. Ultrasound and nuclear magnetic resonance imaging are becoming useful methods for this purpose, but they still lack spatial resolution. In this regard, recent phase contrast x-ray imaging experiments of peripheral nerve allowed the visualization of each nerve fiber surrounded by its myelin sheath as clearly as optical microscopy. In the present study, we attempted to produce high-resolution x-ray phase contrast images of a human sciatic nerve by using synchrotron radiation propagation-based imaging. The images showed high contrast and high spatial resolution, allowing clear identification of each fascicle structure and surrounding connective tissue. The outstanding result is the detection of such structures by phase contrast x-ray tomography of a thick human sciatic nerve section. This may further enable the identification of diverse pathological patterns, such as Wallerian degeneration, hypertrophic neuropathy, inflammatory infiltration, leprosy neuropathy and amyloid deposits. To the best of our knowledge, this is the first successful phase contrast x-ray imaging experiment of a human peripheral nerve sample. Our long-term goal is to develop peripheral nerve imaging methods that could supersede biopsy procedures.     

X-ray diffraction studies on the absolute configuration of alpha- and beta-anordrins

The molecular structures and absolute configurations of alpha- and beta-anordrins are reported. Pure alpha- and beta-epimers were obtained with recrystallization and column chromatography combined with high-pressure liquid chromatography methods; they were identified by high-resolution infrared and mass spectra and 1H and 13C nuclear magnetic resonance. By single crystal x-ray diffraction analysis, the crystals of alpha- and beta-epimers were found to belong to the orthorhombic space groups P2(1)2(1)2(1) and P2(1)2(1)2, respectively. The molecular structures of these two epimers were determined. The absolute configurations were deduced by conformation analysis, 1H nuclear magnetic resonance, and comparison with the absolute configuration of the starting material. The absolute configurations of asymmetric centers of alpha- and beta-epimers were observed to be 2R, 5S, 8R, 9S, 10S, 13S, 14S, 17R, and 2S, 5S, 8R, 9S, 10S, 13S, 14S, 17R, respectively. These results were confirmed by the x-ray diffraction determination of the absolute configuration of 2 alpha,17 alpha-diethynyl-A-nor-5 alpha- androstane-2 beta, 17 beta-diol dichloroacetate.