Radioisotope Studies Research Articles

Pharmacokinetic modeling of phagocytic activity of the liver using superparamagnetic iron oxide nanoparticles in dynamic MR imaging.

The purpose of this study was to determine whether phagocytic activity is measurable by dynamic superparamagnetic iron oxide-enhanced MR imaging. For these experiments on New Zealand White rabbits, which were randomly allocated to normal and silica treated groups, we performed a dynamic MR study and radioisotope study with Tc99m-phytate. In this dynamic MR study, the ratio (Rv) of the distribution volumes of iron oxide (Vm/Ve) could be obtained by applying three- compartment model to the data obtained from the kidney and liver simultaneously. Changes in Rv caused by silica injection and by dosing superparamagnetic iron oxide, AMI-25, were evaluated. In the dynamic MR study using a Beagle dog model the input function could be calculated from data obtained from the hepatic artery and portal vein. Rv's reached maximum values at around 80 minutes after the AMI-25 injection. The Rv of the normal group was 5.06 +/- 1.53 whereas the Rv of the silica treated group was 2.13 +/- 1.20. The results were similar to tissue count data obtained by radioisope study. The Rv value was not dependent on the injected dose of AMI-25. The rate of transport constants (k1, k2, k3) could not be estimated using the 3 compartment model regardless of obtaining the input function. We conclude that Rv may be an quantitative index of decreased phagocytic activity in the liver as determined by dynamic superparamagnetic iron oxide- enhanced MRI.

In Situ Radioisotopic Study of the Active Sites of Sulfide CoMo Catalysts and the Mechanism of Thiophene Hydrodesulfurization

The mechanism of thiophene hydrodesulfurization over sulfide catalysts for hydrotreating and the effect of the catalyst composition and feed on the number, distribution, and performance of active sites were studied using 35S and 3H isotopes. Based on the results of radioisotopic study, a method for systematic testing–monitoring of sulfide Co(Ni)Mo catalysts for hydrotreating is developed. The method involves the evaluation of the fraction of the active phase surface occupied by SH groups and the ratio between the concentrations of the surface SH groups and coordinatively unsaturated sites including functioning vacancies. General conditions for the formation and functioning of active sites are formulated on the basis of the monitoring data. Criteria for evaluation of the catalyst performance under conditions of hydrodesulfurization of various kinds of crude are proposed. The results of the pilot tests of commercial catalysts suggest that the criteria proposed are suitable.

A Radioisotopic Study of the Entry of Calcium Ion into the Maize Kernel During Nixtamalization

ABSTRACTThe entry of calcium ions from the nixtamalization solution into maize kernels over time was followed in model experiments using radiolabeled calcium ions, with autoradiographic evaluation of the kernels after different cooking and steeping times. Calcium ions immediately entered the pericarp and were rapidly fixed at the outer boundary of the endosperm, especially at the external surface of the germ. Entry of calcium into the endosperm occurred gradually after long steeping times, except in the case of broken kernels, for which massive invasion by calcium was observed. After extended steeping times, a moderate amount of calcium‐45 was evident in the germ. Specific perforation of the outer layers of the grains provided a defined route of facilitated entry of calcium into the endosperm. No fundamental difference with respect to penetrability by calcium ion was seen in a comparison between flint‐type grains and grains containing only floury endosperm.

Kinetic analyses of liver phosphatidylcholine and phosphatidylethanolamine biosynthesis using 13C NMR spectroscopy

Choline and ethanolamine are substrates for de novo synthesis of phosphatidylcholine (PtdC) and phosphatidylethanolamine (PtdE) through the CDP-choline and CDP-ethanolamine pathways. In liver, PtdE can also be converted to PtdC by PtdE N-methyltransferase (PEMT). We investigated these kinetics in rat liver during a 60 min infusion with 13C-labeled choline and ethanolamine. NMR analyses of liver extracts provided concentrations and 13C enrichments of phosphocholine (Pcho), phosphoethanolamine (Peth), PtdC, and PtdE. Kinetic models showed that the de novo and PEMT pathways are ‘channeled’ processes. The intermediary metabolites directly derived from exogenous choline and ethanolamine do not completely mix with the intracellular pools, but are preferentially used for phospholipid synthesis. Of the newly synthesized PtdC, about 70% was derived de novo and 30% was by PEMT. PtdC and PtdE de novo syntheses displayed different kinetics. A simple model assuming constant fluxes yielded a modest fit to the data; allowing upregulated fluxes significantly improved the fit. The ethanolamine-to-Peth flux exceeded choline-to-Pcho, and the rate of PtdE synthesis (1.04 μmol/h/g liver) was 2–3 times greater than that of PtdC de novo synthesis. The metabolic pathway information provided by these studies makes the NMR method superior to earlier radioisotope studies.

Methods determining phosphor imaging limits of quantitation in whole-body autoradiography rodent tissue distribution studies affect predictions of 14C human dosimetry

Introduction: Radioluminography, or phosphor imaging, is often used in rodent quantitative whole-body autoradiography (QWBA) studies to determine the tissue distribution and pharmacokinetic (PK) parameters of new pharmaceutical entities in rodents. The rodent tissue pharmacokinetics information are then used to predict human radiation exposure to 14C or 3H during human radioisotope mass balance studies. The human dosimetry estimation can be biased by the method used to determine the lower limit of quantitation (LOQ) of the phosphor imager. A survey of autoradiographers revealed that at least five different methods are used to determine phosphor imager LOQ. The objective of this study is to compare and evaluate the human dosimetry estimates obtained by applying those five LOQ methods to a single set of WBA data. Methods: Five different phosphor imager LOQ determination methods were applied to a single set of QWBA rodent tissue distribution data to produce five tissue concentration time profiles. Tissue PK parameters were determined for each profile and subsequently used to calculate the 14C exposure for a proposed human 14C mass balance study. Results: A threefold difference was observed among the five predictions of human 14C exposure when the five different phosphor imager LOQ values were applied to the initial data set. Discussion: The method chosen to determine the phosphor imaging LOQ for QWBA rodent tissue distribution study could impact the human 14C exposure estimates. The end result may either under- or overestimate the 14C-tissue exposure in humans during radioisotope studies, depending on the method used to determine LOQ. We recommend two approaches to reduce the variations in the determination of rodent tissue distribution pharmacokinetics: (1) Set more sampling time points to cover the terminal phase to obtain more accurate t 1/2 and (2) use Method 3 or the small sized sampling tool of Method 5 for LOQ determinations because it is a balanced approach for both simplicity and accuracy.

Stable isotope approaches, applications, and issues related to polyunsaturated fatty acid metabolism studies.

The use of stable isotope tracers for investigating fatty acid metabolism in human subjects has increased substantially over the last decade. Advances in analytical instrumentation, commercial availability of labeled substrates, and safety considerations are major reasons for this increased use of stable isotope tracers. Several experimental design options are available for using either deuterium or carbon-13 as tracers for fatty acid and lipid studies. Options include feeding a pulse dose of labeled fat or a mixture containing two or more labeled fats. Multiple doses of the labeled fat can be fed at timed intervals to increase enrichments. Administration by injection or continuous intravenous infusion is an alternative. Another option is to use diets containing foods from plants that have slightly higher natural carbon-13 enrichment. Each basic experimental design has its specific strengths, and the best choice of experimental design depends on the study objectives. Stable isotope studies have been used to address a variety of questions related to unsaturated fatty acid metabolism in humans. Examples are provided that illustrate the use of stable isotopes to investigate oxidation of docosahexaenoic acid, desaturation of linoleic and linolenic acids in infants and adults, incorporation of long-chain n-6 and n-3 fatty acids, bioequivalency of linolenic acid in primates, 13C nuclear magnetic resonance spectra of arachidonic acid in living rat brain, and effect of triacylglycerol structure on absorption. Radioisotope and stable isotope tracer studies in animals and humans are responsible for much of our understanding of fatty acid and lipid metabolism. However, tracer studies have limitations, and there are some unresolved issues associated with isotope studies. Examples of unresolved issues are quantification of isotope data, validity of in vivo fatty acid metabolite results, kinetic modeling, subject variability, and use of blood lipid data as a reflection of tissue lipid metabolism. Resolving these issues, developing novel methodology, and applying stable isotope tracer methods to questions related to PUFA metabolism are broad areas of interesting and challenging research opportunities.

BIOSYNTHESIS OF ASCORBIC ACID IN PLANTS: A Renaissance.

The structure of the familiar antioxidant L-ascorbic acid (vitamin C) was described in 1933 yet remarkably, its biosynthesis in plants remained elusive until only recently. It became clear from radioisotopic labeling studies in the 1950s that plant ascorbic acid biosynthesis does not proceed in toto via a route similar to that in mammals. The description in 1996 of an Arabidopsis thaliana mutant deficient in ascorbic acid prompted renewed research effort in this area, and subsequently in 1998 a new pathway was discovered that is backed by strong biochemical and molecular genetic evidence. This pathway proceeds through the intermediates GDP-D-mannose, L-galactose, and L-galactono-1,4-lactone. Much research has focused on the properties of the terminal enzyme responsible for conversion of the aldonolactone to ascorbate, and on related enzymes in both mammals and fungi. Two of the plant biosynthetic genes have been studied at the molecular level and additional ascorbate-deficient A. thaliana mutants may hold the key to other proteins involved in plant ascorbate metabolism. An analysis of the biosynthesis of ascorbate and its analogues in algae and fungi as well as the study of alternative proposed pathways should broaden our understanding of ascorbate metabolism in plants. With a biosynthetic pathway in hand, research on areas such as the control of ascorbate biosynthesis and the physiological roles of ascorbate should progress rapidly.

Assessment of peripheral arterial vascular disease with radionuclide techniques

Various radioisotopic imaging techniques for noninvasive detection of vessel stenosis and for functional investigation of reduced blood flow and follow-up have been developed during the last decade in peripheral vascular disease (PVD), with the aim of replacing invasive techniques and complementing standardized methods. Radionuclide assessment of PVD is divided into 2 major groups: imaging of perfusion and metabolic investigations. The measurement of arterial blood flow and muscle perfusion is intended to show the morphology, to evaluate the functional consequences of PVD, and to quantify the latter. The application of radiolabeled tracers was developed as a noninvasive alternative to angiography in morphologic imaging. Treadmill testing has been used to assess the functional effects of reduced blood flow in PVD where the onset of pain indicates the stage of disease, but the results can be confused by other symptoms. Scintigraphic measurement of muscle perfusion should detect insufficient nutritional blood flow in peripheral muscle and thus have a higher specificity for PVD than treadmill testing alone. Although there are very promising theoretical and experimental data in animals, the clinical use of radionuclide investigations is limited by different technical problems, such as methodologic differentiation between skin and muscle perfusion, the lack of controlled and prospective studies, and incomplete correlation with other standardized routine techniques. Among the great number of radioisotopic metabolic imaging techniques, only radiolabeled platelets and lipoproteins, to some extent, have shown a limited potential clinical use. Some other approaches seem to have a high potential from a theoretical point of view. They are limited, however, by a great number of problems. Correlation with sonographic or magnetic resonance imaging (MRI) findings may identify a potential metabolic value. Correlation with angiography reflecting the extent of the disease makes no sense. So far with PVD, neither radioisotopic perfusion studies nor metabolic imaging techniques are able to achieve a level of routine application or wider meaningful interpretation of the clinical condition of a specific patient. Competing techniques are easier to perform, less expensive, faster, more widely available, and do not carry the radiation burden. Positron emission tomography is still in its early stages of application, with great theoretical potential but at a high price. A great deal of work is still required to transform in vitro and experimental experience into more meaningful routine radioisotopic investigations in patients with PVD.

Effect of exogenous siderophores on iron uptake activity of marine bacteria under iron-limited conditions.

More than 60% of species examined from a total of 421 strains of heterotrophic marine bacteria which were isolated from marine sponges and seawater were observed to have no detectable siderophore production even when Fe(III) was present in the culture medium at a concentration of 1.0 pM. The growth of one such non-siderophore-producing strain, alpha proteobacterium V0210, was stimulated under iron-limited conditions with the addition of an isolated exogenous siderophore, N,N'-bis (2,3-dihydroxybenzoyl)-O-serylserine from a Vibrio sp. Growth was also stimulated by the addition of three exogenous siderophore extracts from siderophore-producing bacteria. Radioisotope studies using (59)Fe showed that the iron uptake ability of V0210 increased only with the addition of exogenous siderophores. Biosynthesis of a hydroxamate siderophore by V0210 was shown by paper electrophoresis and chemical assays for the detection of hydroxamates and catechols. An 85-kDa iron-regulated outer membrane protein was induced only under iron-limited conditions in the presence of exogenous siderophores. This is the first report of bacterial iron uptake through an induced siderophore in response to exogenous siderophores. Our results suggest that siderophores are necessary signaling compounds for growth and for iron uptake by some non-siderophore-producing marine bacteria under iron-limited conditions.

Submandibular Gland Transfer: A New Method of Preventing Radiation‐Induced Xerostomia

Radiation-induced xerostomia is a significant morbidity of radiation therapy in the management of patients with head and neck cancers. We have recently reported a method of transfer of one submandibular gland to the submental space in a small pilot series of eligible surgical patients. The submental space was shielded during postoperative radiation therapy. The transferred gland continued to function after the completion of radiation therapy and none of the patients developed xerostomia. The purpose of this article is to present the technique of submandibular gland transfer in detail and to evaluate the postoperative survival and function of the transferred submandibular glands. Prospective clinical trial. The submandibular gland was transferred on eligible patients as part of their surgical intervention. The patients were followed clinically, with salivary flow and radioisotope studies. We performed the surgical transfer of the submandibular salivary gland in 24 of 25 patients placed on the protocol. All the glands survived transfer and functioned well postoperatively as demonstrated on the salivary flow and the radioisotope studies. The surgical transfer was relatively simple and added 45 minutes to the surgical procedure. There were no complications attributed to the submandibular gland transfer. We have successfully demonstrated that the submandibular gland can be surgically transferred to the submental space with its function preserved. The gland seems to continue functioning even after radiation therapy with the appropriate shielding. This surgical transfer procedure has the potential to change the way we currently manage patients with head and neck cancer.

Infección de bypass de Dacron aorto-tronco braquiocefálico

We describe apatient that underwent surgical reconstruction of inniminate artery for atrherosclerotic occlusive disease elevenyears ago (aorto-brachiocephalic trunkDacron by-pass), and now he presents a pre-sterno tumouration. We suspect a vascular prosthetic infection so we do: blood and biochemical tests, bascteriological cultures, anatomopatologic study, thoracic CT scan, radioisotopic study with leukocytes labels with technicium 99 m , supraortic trunks eco-Doppler andsupraortic arteriography. We did surgery in two times: in a first time we did an extra-anatomic revasculation consisted of carotid-carotid by-pass and right primitive carotid-right subclavian by-pass, both of them with vena safena. In a second time we took off the aorto-brachiocephlaic Dacronprosthesis. After one year the by-pass were permeable and the patient was asymptomatic. Presentamos el caso de un paciente portador de un bypass aorto-tronco braquiocefálico conprótesis de Dacron permeable clínicamente realizado hace 11 años por síndrome de robo de subclavia sintomático, que acude a nuestro centro por presentar tumoración fluctu ante no pulsátil en la horquilla esternal de dos semanas de evolución. Ante la sospecha de infección de laprótesis se realizan los siguientes estudios: analítica general, citologíay microbiología de material de la tumoración, TAC torácica, gammagrafía con leucocitos marcados con tecnecio 99 m , ecografía Doppler de troncos supraórticos y arteriografía de troncos supraórticos. Se realizó intervención quirúrgica en dos tiempos, en un primer tiempo se revascularizó la carótida y la subclavia derecha mediante bypass carótido-carotídeo retrofaríngeoy carótidosubclavio con vena safena; en un segundo tiempo se retiró la prótesis de Dacron aorto-tronco braquiocefálico. Al año de seguimiento los injertos se mantienen permeables y el paciente permanece asintomático. Apresentamos o caso de um doente portador de um bypass aorto-tronco-braquiocefálico com prótese de Dacron clinicamente permeável, realizado há 11 anos por síndroma de subtracçâo da subclávia, sintomático, o doente recorre ao nosso centro por apresentar tumefacçâo flutuante nao pulsátil nafórcula esternal com duas semanas de evoluçâo. Perante a suspeita de infecçâo da prótese, realizam-se os seguintes estudos: analises de rotina, citologia e microbiologia do material da tumefacçâo, TAC torácico, gamagrafia com leucócitos marcados com tecnécio 99 m , eco-Doppler dos troncos supra-aórticos e arteriografia dos troncos supra-aórticos. A intervençâo cirúrgica realizou-se em dois tempos, n um primeiro tempo revascularizou-se a carótida e a subclávia direita por bypass carótido-carotídeo retrofaríngeo e carótido-subclávio com veia safena; no segundo momento retirou-se a prótese de Dacron aorto-tronco braquiocefálico. Ao ano de seguimento os enxertos estâo perme-áveis e o doente permanece assintomático.

Size-fractionated primary production and nitrogen uptake during a North Atlantic phytoplankton bloom: implications for carbon export estimates

A Lagrangian experiment was set up at 47°N 20°W in the northeast Atlantic as part of the Joint Global Ocean Flux Study (JGOFS) programme. As an integral part of the programme, this study investigated the uptake of carbon and nitrogen into different algal size classes, and quantified the export of carbon using 15 N stable isotope and 14 C radioisotope studies. Good quality f-ratio field data is of fundamental importance to multi-compartment nitrogen-based upper ocean ecosystem modelling of carbon fluxes: this study provides an appraisal of current north Atlantic field measurements making comparisons with our findings. A phytoplankton bloom was tracked for 18 d from 1 May 1990. Waters were initially well-mixed with surface nutrients of 4–6 mmol NO 3 m −3 and 1.5–2.5 mmol SiO 4 m −3 and surface biomass of 1–1.5 mg chl a m −3, indicating the likely onset of a bloom. Increased insolation and vertical stability produced a diatom-dominated bloom with a surface biomass peak of 3.5 mg chl a m −3, decreased nutrient values (0.5 mmol NO 3 m −3, 0.35 mmol SiO 4 m −3), and maximum integrated carbon uptake values of 1970 mg C m −2 d −1 on 17 May. Maximum nitrogen uptake values of 251 mg NO 3 m −2 d −1 were measured on 14 May during the greatest flagellate growth phase. Integrated production rates over the experiment ranged from 0.5 to 1.0 g C m −2 d −1, and carbon export was estimated at 480 (using NO 3 uptake and Redfield ratios) or 570 (using integrated C assimilation values and the mean weighted f-ratio) mg C m −2 d −1. The decoupling of maximum carbon and nitrogen uptake rates over a three-day period indicates that it may not be appropriate to use Redfield ratios to convert nitrate-estimated new production to carbon export values, even over time scales of a month. Primary production values are comparable to 1989 North Atlantic Bloom Experiment (NABE) data, despite the fact that phytoplanktonic taxonomic data for the 1990 bloom were very different from the more typical bloom conditions of 1989. Throughout the experiment the greatest biomass occurred in the 1–5 μm size range, which accounted for an average of 50% of the total production and >50% of nitrate uptake and ammonium uptake. In addition, both the net- and nanoplankton communities preferentially assimilated nitrate, which challenges the assumption that new production can be directly equated to export production on the time-scale of weeks.

A randomized controlled trial of psychotherapy in patients with chronic functional dyspepsia

Background & Aims: This study aimed to determine whether brief psychodynamic-interpersonal (PI) psychotherapy is more efficacious than a psychological control for patients with chronic, intractable functional dyspepsia (FD), and whether patients with abnormal gastric function respond differently than those with normal gastric function. Methods: Ninety-five consecutive patients with chronic symptoms of FD who had failed to respond to conventional pharmacologic treatments were approached. Thirty-seven received PI psychotherapy, and 36 the control condition (supportive therapy). Patients completed self-report questionnaires before and after treatment and 12 months later. The patients' gastroenterologists, who were blind to the study groups, conducted independent ratings before and after treatment. Forty-nine patients also underwent a radioisotope gastric emptying study. An intention-to-treat analysis was used with baseline scores as covariates. Results: At the end of treatment, there were significant advantages for PI psychotherapy compared with controls for the gastroenterologists' (P = 0.002) and patients' total symptom score (P = 0.015). One year after treatment, the symptomatic scores were similar. However, a subanalysis showed that PI therapy was superior to the control condition at 1 year, when patients with severe heartburn were excluded. There was no difference in outcome between patients with normal and abnormal gastric emptying. Conclusions: PI therapy may have both short- and long-term effects in patients with dyspepsia, but further evaluation is required. Its cost-effectiveness needs to be determined.GASTROENTEROLOGY 2000;119:661-669

Hydrogen radioisotopic labelling studies using muonium: properties of thiyl radicals potentially relevant to cellular membrane damage

Hydrogen radioisotopic labelling studies using muonium: properties of thiyl radicals potentially relevant to cellular membrane damage

Rhinoscintigraphy: a simple radioisotope technique to study the mucociliary system.

This was a radioisotope study of nasal mucociliary clearance of total and subtotal nasal obstruction. Rhinoscintigraphy was performed by insufflating 1.85 MBq (69 mCi) Tc-99m MAA in 20 patients. Six cases were regarded as the control group, because the presence of small spurs does not affect nasal patency. The remaining 14 patients had various rhinopathic conditions. Two regions of interest were selected, one in the nasal cavity and one in the pharynx. Mucociliary transport speed was calculated. This parameter appeared to be a sensitive index for the assessment of the degree of mucociliary alteration. It showed that polyposis impairs mucociliary transport most severely, thus confirming the results of other published studies. Rhinoscintigraphy proved to be a reliable, easily reproducible, and harmless method, so it may be used for follow-up examinations in patients who have had surgery of the nose and paranasal sinuses, and for drug therapy of rhinopathic conditions.

Accelerated tissue regeneration through incorporation of basic fibroblast growth factor-impregnated gelatin microspheres into artificial dermis

The objective of this study was to evaluate the effect of incorporation of basic fibroblast growth factor (bFGF)-impregnated gelatin microspheres into an artificial dermis on the regeneration of dermis-like tissues. When used in the free form in vivo, bFGF cannot induce sufficient wound healing activity, because of its short half-life. Therefore, sustained release of bFGF was achieved by impregnation into biodegradable gelatin microspheres. A radioisotope study revealed that incorporation of bFGF-impregnated gelatin microspheres significantly prolonged in vivo retention of bFGF in the artificial dermis. Artificial dermis with incorporated bFGF-impregnated gelatin microspheres or bFGF in solution was implanted into full-thickness skin defects on the back of guinea pigs (1.5 cm×1.5 cm) ( n=4). Incorporation of bFGF into the artificial dermis accelerated fibroblast proliferation and capillary formation in a dose-dependent manner. However, the accelerated effects were more significant with the incorporation of bFGF-impregnated gelatin microspheres than with free bFGF at doses of 50 μg or higher. We conclude that the gelatin microsphere is a promising tool to accelerate bFGF-induced tissue regeneration in artificial dermis.

Hydrogen radioisotopic labelling studies using muonium: properties of thiyl radicals potentially relevant to cellular membrane damage

Thiyl radicals (RS·) are formed labelled with muonium atoms (a radioisotope of hydrogen with a positive muon as the nucleus) and detected using the muon spin rotation (MuSR) method. This approach is shown to be extremely effective in the study of thiyl radicals, in non-aqueous (membrane-like) environments, from which details of the structures of these reactive free radicals and their reaction kinetics were determined. In this regard, the method is superior to conventional ESR spectroscopy, to which thiyl radicals are undetectable in liquid solution, and to pulse-radiolysis experiments, which are limited to aqueous media; the rate constants for the reactions of thiyl radicals with lipids but also with antioxidants such as β-carotene and (SH)glutathione are found to be enhanced in non-aqueous media. Copyright © 2000 John Wiley & Sons, Ltd.

Tc-99m MAG3 evaluation of recipients with dual adult cadaveric renal allografts. Simultaneous transplantation of both kidneys from marginal donors.

The application of Tc-99m mercaptoacetyl triglycine (MAG3) renal scintigraphy in patients who had simultaneous unilateral retroperitoneal transplant of both kidneys from marginal adult cadaveric donors is assessed. Eighteen patients who had this unusual form of kidney transplant were monitored and evaluated by Tc-99m MAG3 renal scintigraphy. More than 60 of the radioisotopic studies, including immediate postoperative and subsequent follow-up examinations, were performed among these patients. In all the studies, the two transplanted kidneys were not equally well visualized by this scintigraphic procedure because of the inherent difference in their depth from the body surface, a feature of this particular surgical design. Despite this limitation, the efficacy of the scintigraphic procedure for such dual renal allografts appears to be similar to that established for kidney transplants performed in the conventional manner. To use the scintigraphic procedure effectively, certain sensible and logical adjustments are needed for the comparative visual and semiquantitative assessments of the two kidneys in this special form of transplantation.

Lipid distress-syndrome in surgery

The paper reviews the results of treatment of lipid distress-syndrome manifested in obliterating atherosclerosis, gallbladder cholesterosis, chronic abdominal ischemia, lipid pancreatitis, and lipid hepatosis. New diagnostic methods for these diseases are described. The efficiency of partial ileal bypass and conservative treatment with mineral oil-pectin emulsion Fishant in correcting dyslipoproteinemia is demonstrated. The therapeutic results are confirmed by radioisotopic and ultrasonic studies.

Diagnosis and treatment of diabetic foot infections.

Prompt clinical diagnosis and timely treatment are the hallmarks of the proper care of diabetic patients with foot infections. The importance of careful clinical foot examination cannot be overemphasized. When infection is suspected, effort should be made to search for deeper infections, especially osteomyelitis. Numerous imaging techniques are available, but their cost-effectiveness has not been fully determined. Radiography of the foot is less sensitive but can provide useful information at a lower cost. Radio-isotope studies have not yielded consistent results, but the newer techniques deserve attention. Microbiological diagnosis should be attempted using only deep tissue culture, including bone biopsy. The primary aim of treatment of the infected foot is to restore ambulation. Timely surgical intervention and appropriate antimicrobial therapy can reduce the incidence of above-ankle amputation and reduce the length of hospital stay.