Pre-transplant kidney quality evaluation using photoacoustic imaging during normothermic machine perfusion

Due to the shortage of kidneys donated for transplantation, surgeons are forced to use the organs with an elevated risk of poor function or even failure. Although the existing methods for pre-transplant quality evaluation have been validated over decades in population cohort studies across the world, new methods are needed as long as delayed graft function or failure in a kidney transplant occurs. In this study, we explored the potential of utilizing photoacoustic (PA) imaging during normothermic machine perfusion (NMP) as a means of evaluating kidney quality. We closely monitored twenty-two porcine kidneys using 3D PA imaging during a two-hour NMP session. Based on biochemical analyses of perfusate and produced urine, the kidneys were categorized into 'non-functional' and 'functional' groups. Our primary focus was to quantify oxygenation (sO2) within the kidney cortical layer of depths 2 mm, 4 mm, and 6 mm using two-wavelength PA imaging. Next, receiver operating characteristic (ROC) analysis was performed to determine an optimal cortical layer depth and time point for the quantification of sO2 to discriminate between functional and non-functional organs. Finally, for each depth, we assessed the correlation between sO2 and creatinine clearance (CrCl), oxygen consumption (VO2), and renal blood flow (RBF). We found that hypoxia of the renal cortex is associated with poor renal function. In addition, the determination of sO2 within the 2 mm depth of the renal cortex after 30 min of NMP effectively distinguishes between functional and non-functional kidneys. The non-functional kidneys can be detected with the sensitivity and specificity of 80% and 85% respectively, using the cut-off point of sO2 < 39%. Oxygenation significantly correlates with RBF and VO2 in all kidneys. In functional kidneys, sO2 correlated with CrCl, which is not the case for non-functional kidneys. We conclude that the presented technique has a high potential for supporting organ selection for kidney transplantation.

Photoacoustic imaging on its way toward clinical utility: a tutorial review focusing on practical application in medicine

Significance

Photoacoustic imaging (PAI) enables the visualization of optical contrast with ultrasonic imaging. It is a field of intense research, with great promise for clinical application. Understanding the principles of PAI is important for engineering research and image interpretation.

Aim

In this tutorial review, we lay out the imaging physics, instrumentation requirements, standardization, and some practical examples for (junior) researchers, who have an interest in developing PAI systems and applications for clinical translation or applying PAI in clinical research.

Approach

We discuss PAI principles and implementation in a shared context, emphasizing technical solutions that are amenable to broad clinical deployment, considering factors such as robustness, mobility, and cost in addition to image quality and quantification.

Results

Photoacoustics, capitalizing on endogenous contrast or administered contrast agents that are approved for human use, yields highly informative images in clinical settings, which can support diagnosis and interventions in the future.

Conclusion

PAI offers unique image contrast that has been demonstrated in a broad set of clinical scenarios. The transition of PAI from a "nice-to-have" to a "need-to-have" modality will require dedicated clinical studies that evaluate therapeutic decision-making based on PAI and consideration of the actual value for patients and clinicians, compared with the associated cost.

Real-time laser speckle contrast imaging measurement during normothermic machine perfusion in pretransplant kidney assessment

OBJECTIVES

Normothermic machine perfusion (NMP) provides a platform for pre-transplant kidney quality assessment that is essential for the use of marginal donor kidneys. Laser speckle contrast imaging (LSCI) presents distinct advantages as a real-time and noncontact imaging technique for measuring microcirculation. In this study, we aimed to assess the value of LSCI in visualizing renal cortical perfusion and investigate the additional value of dual-side LSCI measurements compared to single aspect measurement during NMP.

METHODS

Porcine kidneys were obtained from a slaughterhouse and then underwent NMP. LSCI was used to measure one-sided cortical perfusion in the first 100 min of NMP. Thereafter, the inferior renal artery branch was occluded to induce partial ischemia and LSCI measurements on both ventral and dorsal sides were performed.

RESULTS

LSCI fluxes correlated linearly with the renal blood flow (R2  = 0.90, p < 0.001). After renal artery branch occlusion, absence of renal cortical perfusion could be visualized and semiquantified by LSCI. The overall ischemic area percentage of the ventral and dorsal sides was comparable (median interquartile range [IQR], 38 [24-43]% vs. 29 [17-46]%, p = 0.43), but heterogenous patterns between the two aspects were observed. There was a significant difference in oxygen consumption (mean ± standard deviation [SD], 2.57 ± 0.63 vs. 1.83 ± 0.49 mLO2 /min/100 g, p < 0.001), urine output (median [IQR], 1.3 [1.1-1.7] vs. 0.8 [0.6-1.3] mL/min, p < 0.05), lactate dehydrogenase (mean ± SD, 768 ± 370 vs. 905 ± 401 U/L, p < 0.05) and AST (mean ± SD, 352 ± 285 vs. 462 ± 383 U/L, p < 0.01) before and after renal artery occlusion, while no significant difference was found in creatinine clearance, fractional excretion of sodium, total sodium reabsorption and histological damage.

CONCLUSIONS

LSCI fluxes correlated linearly with renal blood flow during NMP. Renal cortical microcirculation and absent perfusion can be visualized and semiquantified by LSCI. It provides a relative understanding of perfusion levels, allowing for a qualitative comparison between regions in the kidney. Dual-side LSCI measurements are of added value compared to single aspect measurement and renal function markers.

Ultrasound-guided breast biopsy using an adapted automated cone-based ultrasound scanner: a feasibility study

BACKGROUND

Among available breast biopsy techniques, ultrasound (US)-guided biopsy is preferable because it is relatively inexpensive and provides live imaging feedback. The availability of magnetic resonance imaging (MRI)-3D US image fusion would facilitate US-guided biopsy even for US occult lesions to reduce the need for expensive and time-consuming MRI-guided biopsy. In this paper, we propose a novel Automated Cone-based Breast Ultrasound Scanning and Biopsy System (ACBUS-BS) to scan and biopsy breasts of women in prone position. It is based on a previously developed system, called ACBUS, that facilitates MRI-3D US image fusion imaging of the breast employing a conical container filled with coupling medium.

PURPOSE

The purpose of this study was to introduce the ABCUS-BS system and demonstrate its feasibility for biopsy of US occult lesions.

METHOD

The biopsy procedure with the ACBUS-BS comprises four steps: target localization, positioning, preparation, and biopsy. The biopsy outcome can be impacted by 5 types of errors: due to lesion segmentation, MRI-3D US registration, navigation, lesion tracking during repositioning, and US inaccuracy (due to sound speed difference between the sample and the one used for image reconstruction). For the quantification, we use a soft custom-made polyvinyl alcohol phantom (PVA) containing eight lesions (three US-occult and five US-visible lesions of 10 mm in diameter) and a commercial breast mimicking phantom with a median stiffness of 7.6 and 28 kPa, respectively. Errors of all types were quantified using the custom-made phantom. The error due to lesion tracking was also quantified with the commercial phantom. Finally, the technology was validated by biopsying the custom-made phantom and comparing the size of the biopsied material to the original lesion size. The average size of the 10-mm-sized lesions in the biopsy specimen was 7.00 ± 0.92 mm (6.33 ± 1.16 mm for US occult lesions, and 7.40 ± 0.55 mm for US-visible lesions).

RESULTS

For the PVA phantom, the errors due to registration, navigation, lesion tracking during repositioning, and US inaccuracy were 1.33, 0.30, 2.12, and 0.55 mm. The total error was 4.01 mm. For the commercial phantom, the error due to lesion tracking was estimated at 1.10 mm, and the total error was 4.11 mm. Given these results, the system is expected to successfully biopsy lesions larger than 8.22 mm in diameter. Patient studies will have to be carried out to confirm this in vivo.

CONCLUSION

The ACBUS-BS facilitates US-guided biopsy of lesions detected in pre-MRI and therefore might offer a low-cost alternative to MRI-guided biopsy. We demonstrated the feasibility of the approach by successfully taking biopsies of five US-visible and three US-occult lesions embedded in a soft breast-shaped phantom.

Quantitative Evaluation of an Automated Cone-Based Breast Ultrasound Scanner for MRI-3D US Image Fusion

Breast cancer is one of the most diagnosed types of cancer worldwide. Volumetric ultrasound breast imaging, combined with MRI can improve lesion detection rate, reduce examination time, and improve lesion diagnosis. However, to our knowledge, there are no 3D US breast imaging systems available that facilitate 3D US - MRI image fusion. In this paper, a novel Automated Cone-based Breast Ultrasound System (ACBUS) is introduced. The system facilitates volumetric ultrasound acquisition of the breast in a prone position without deforming it by the US transducer. Quality of ACBUS images for reconstructions at different voxel sizes (0.25 and 0.50 mm isotropic) was compared to quality of the Automated Breast Volumetric Scanner (ABVS) (Siemens Ultrasound, Issaquah, WA, USA) in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and resolution using a custom made phantom. The ACBUS image data were registered to MRI image data utilizing surface matching and the registration accuracy was quantified using an internal marker. The technology was also evaluated in vivo. The phantom-based quantitative analysis demonstrated that ACBUS can deliver volumetric breast images with an image quality similar to the images delivered by a currently commercially available Siemens ABVS. We demonstrate on the phantom and in vivo that ACBUS enables adequate MRI-3D US fusion. To our conclusion, ACBUS might be a suitable candidate for a second-look breast US exam, patient follow-up, and US guided biopsy planning.

Chemical bonding between thorium atoms and a carbon hexagon in carbon nanomaterials

We explore the unusual nature of chemical bonding of thorium atoms with a ring of six carbon atoms (hexagon) in novel carbon materials. Our ab initio calculations of Th-based metallofullerenes (Th@C60 and Th@C20) and Th bound to benzene or coronene at the Hartree-Fock level with the second order perturbation (MP2) correction accounting for the van der Waals interactions demonstrate that the optimal position of the thorium atom is where it faces the center of a hexagon and is located at a distance of 2.01-2.07 Å from the center. For Th encapsulated in C60 it is found at 2.01 Å, whereas the other local energy minima are shifted to larger energies (0.22 eV and higher). Inside C60 the highest local minimum at 1.17 eV is observed when Th faces the center of the five member carbon ring (pentagon). Based on our calculations for Th with benzene and coronene where the global minimum for Th corresponds to its position at 2.05 Å (benzene) or 2.02 Å (coronene) from the hexagon center, we conclude that a well pronounced minimum is likely to be present in graphene and in a single wall carbon nanotube. The ground state of Th is singlet, and other high spin states (triplet and quintet) lie higher in energy (>1.62 eV). We discuss a potential use of carbon nanomaterials with the 229Th isotope having its nuclear transition in the optical range, for metrological purposes.

[Surgical-associated expansion of the jaws with asymmetric deformations]

One of the most common abnormalities in the development of the jaw is the narrowing of the alveolar process of the maxilla. In childhood, the elimination of such a deformation is quite common. But with age, the only effective option is the inclusion of a surgical procedure in the rehabilitation plan. The medial and parasagittal osteotomy of the maxilla for the purpose of its expansion by a distraction device has a number of important nuances which can significantly affect the result. These include: localization of sagittal osteotomy of the palate and alveolar process; the direction of cutting the walls of the maxillary sinus; type of fixation of the device (dental-borne or bone-borne). The article summarizes the experience of 74 surgical-associated expansions of the jaws with asymmetric deformations performed over 2 years. A retrospective analysis according to cone beam computed tomography is given. of complex treatment with the inclusion of sparing osteotomy of the maxilla in the rehabilitation plan and a differentiated approach to performing surgical manipulation allow to achieve optimal aesthetic and functional results and to correct the asymmetry to the greatest extent.

Influence of Natural Polyphenols on Isolated Yeast Dipodascus magnusii Mitochondria

The effect of stilbene polyphenols (resveratrol and pinosilvin) and flavonoids (dihydromyricetin, epigallocatechin, and dihydroquercetin) on producing the reactive oxygen species (ROS) due to cell respiration using the isolated mitochondria of the fungus Dipodascus (Endomyces) magnusii was studied. It was shown that the inhibition of the ROS generation with stilbenes is related to both the oxygen consumption inhibition and their antioxidant properties. The degree of manifestation of polyphenol antioxidant properties depended on the number of hydroxyl groups in a polyphenol molecule. Of the flavonoids tested, dihydromyricetin was most active in reducing the ROS generation, but its inhibitory effect on oxygen consumption by mitochondria was significantly lower as compared to that of the stilbenes. The data obtained show that the mechanism of reducing the ROS generation with polyphenols is associated with both the respiratory inhibition and their antioxidant properties.

A New Recombinant Strain of Yarrowia lipolytica Producing Encapsulated Phytase from Obesumbacterium proteus

A new recombinant strain of Yarrowia lipolytica synthesizing encapsulated highly thermostable phytase of Obesumbacterium proteus, which is recommended for use as a premix component of feed compositions in animal husbandry, was obtained.

[Comparative biomechanical study of surgically assisted rapid palatal expansion with tooth-borne and bone-borne expanders]

The study objective was to compare the biomechanics of surgically assisted rapid palatal expansion (SARPE) with tooth-borne and bone-borne expanders. Materials include a sample of 54 cone-beam CT of 27 patients who underwent SARPE (bone-borne, n=21; tooth-borne, n=6) before treatment and at expander removal. Expansion efficacy was estimated by interapecal and intercoronal distances between maxillary canines, premolars and first molars as well as Coronal-Apical Index (CAI = coronal expansion (mm)/apical expansion (mm)). CAI varied between 1.5 and 2.0 in the group of patients with bone-borne appliances, and from 2.3 to 2.6 in the tooth-borne appliances group. The maximal amount of vestibular coronal declination was revealed in premolars by the use of tooth-borne appliances. Bone-borne appliances allowed lateralization of maxilla and the most prominent effect of tooth shift in a vestibular direction, which may be seen as the most important factors in a relapse prevention.

[The choice of coating materials for vestibuloplasty and pre- and postoperative use of pain and sedative medications depending on patient emotional features]

The purpose of the message was the comparison of change in the width and quality of keratinized tissue created in the lower vestibuloplasty area. Preliminary results of the case-control study involving 71 patients showed that autotransplantation managed to create the necessary buffer zone with the desired thickness of the mucosa and is particularly justified in cases of «washing board effect». However, the method is technically complicated and more expensive and painfull for patients. The use of alternative materials of artificial origin, such as «Mucograft» and bloodstatic and desinfecting sponge simplifies the procedure technique thereby reducing operational risk but often does not lead to the formation of a fully keratinized gingiva.

Novel efficient promoter of the mitochondrial porin, voltage-dependent anion channel (VDAC), in the genome of the Yarrowia lipolytica yeast

This article presents the characteristics of the highly inducible promoter of the gene encoding the mitochondrial porin, the voltage-dependent anion channel (VDAC). This promoter is recommended for use in new genetic constructs both in basic research for assessing the adaptive strategy of lower eukaryotes under adverse conditions and in designing new highly competitive transformants producing economically important compounds (proteins, lipids, and organic acids) on its basis.

«Surgery first» or two stage complex rehabilitation plan for patients with malocclusions

The article considers stages of complex rehabilitation treatment plans of patients with bite anomalies. The study included 515 patients with various complex malocclusions. Two and conventional three stage treatment plans are described. The article suggests indications for the two stage treatment protocol. The evaluation of efficiency and stability of achieved treatment results obtained with a help of the system of quantitative analysis of dentooralfacial disorders is presented.

Modified gene lacZ encoding β-galactosidase as efficient transcriptional reporter for the Yarrowia lipolytica yeast

A modified variant of the β-galactosidase gene from Escherichia coli (lacZ) has been obtained. This was designed for building transcriptional reporter constructs, the product of which possesses a higher proteolytic resistance in the Yarrowia lipolytica yeasts. The study of the activity of mitochondrial voltagedependent porin (voltage-dependent anion channel, VDAC) showed a high efficiency of the reporter system based on the designed lacZ reporter compared to the wild-type lacZ gene.

Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions

In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the u̇l-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets.

[Comparative study of long term result of auto- and allografts for keratinized gingiva restoration in vestibuloplasty area on the lower jaw]

The purpose of the study was to assess the changes in the width and quality of keratinized tissue created in the area of vestibuloplasty on the lower jaw. Preliminary results of the study showed that autotransplantation method allows creating proper buffer zone with the desired mucosa thickness and is particularly justified in cases of "washing board" effect. However, the method is technically more demanding and is more expensive and painfull for patients. The use of alternative materials of artificial origin, such as "Mucograft" and "Tachocomb" simplifies the execution of operation, thereby reducing operational risk, but often does not lead to the formation of a fully keratinized gingiva.

Synthetic neoglycoconjugates of cell-surface phosphoglycans of Leishmania as potential anti-parasite carbohydrate vaccines

Leishmania are a genus of sandfly-transmitted protozoan parasites that cause a spectrum of debilitating and often fatal diseases in humans throughout the tropics and subtropics. During the parasite life cycle, Leishmania survive and proliferate in highly hostile environments. Their survival strategies involve the formation of an elaborate and dense cell-surface glycocalyx composed of diverse stage-specific glycoconjugates that form a protective barrier. Phosphoglycans constitute the variable structural and functional domain of major cell-surface lipophosphoglycan and secreted proteophosphoglycans. In this paper, we discuss structural aspects of various phosphoglycans from Leishmania with the major emphasis on the chemical preparation of neoglycoconjugates (neoglycoproteins and neoglycolipids) based on Leishmania lipophosphoglycan structures as well as the immunological evaluation for some of them as potential anti-leishmaniasis vaccines.

[The long-term follow-up results of the colon cancer treatment]

Results of treatment of 298 patients with colon cancer in the absence of distant metastases were analyzed. The long-term follow-up results were obtained after up to 20 years; 10 years follow-up results were obtained in 95% of the operated patients. The survival rate was significantly dependant on the stage of the disease, i.e., on the presence of regional lymph nodes invasion. Authors conclude, that possibilities of surgical treatment in further improvement of survival rates are to certain limited and exhausted. Therefore, further workout of perioperative combined chemo- and radiotherapy of patients with colon cancer is expected to improve the results.

[Long-term results of surgery and preoperative hypoxyradiotherapy for colorectal cancer]

Combined treatment for colorectal cancer involving preoperative hypooxyradiotherapy was used to boost targeted irradiation of tumor cells. End results were significantly improved due to the decrease in the number of distant metastases even in cases of poor prognosis because of lymph node involvement.

[Polyradiomodification as component of combined treatment of rectal cancer: rationale and results]

The report discusses our 30-year experience with surgical and combined treatment of rectal cancer. In cases of preoperative radiotherapy, loco-regional frequency of relapse dropped to 9.6% as compared with surgery (16.3%). After preoperative thermoradiotherapy it fell to 4.6%; polyradiomodification - 0.5% (3-year follow-up). Distant metastasis formation rates were: after polyradiomodification--1.5%, radiotherapy--9.6%, and thermo-radiotherapy--6%. Recurrence-free survival rates (3 years) were: polyradiomodification--97.3%, thermo-radiotherapy--75.9%, radiotherapy--71.1%, and surgery--58%. Data on regimens and dosage of polyradiomodification alongside radiation damage for different combinations of treatment are presented.

[Interaction of influenza A and B viruses with a carbon-containing sorbent]

The investigation demonstrated that influenza A and B viruses actively interacted with a sorbent obtained from modified oxygen-containing graphite via hydrothermal treatment irrespective of the antigenic structure of surface proteins. Virionic sorption occurred in a wide range of temperatures from 8 to 34 degrees C for 15 min or more. After interaction with the sorbent, the titer of a virus decreased 4- to 256-fold. The immobilized viruses were able to interact with homologous antibodies and immune sera. Desorption of viruses with the sorbent was extremely slight. In addition to viruses, the proteins of nonviral nature--those of allantoic hen embryo liquid, immune serum, and 1% bovine serum albumin--could be immobilized to the sorbent.

[Combined treatment for rectal cancer using different radiomodification means]

The paper presents an evaluation of the results of surgical and combined treatment received by 961 patients at the Center's Clinics within 28 years. The analysis was based on 3 protocols of prospective randomized study. It dealt with assessment of the end results of surgical and combined treatment for operable rectal cancer using one preoperative hyperfractonated STD of 5-25 Gy. That was combined with local microwave hyperthermia and two radio modifiers--local microwave hyperthermia+intrarectal administration of a preparation containing metronidazolum. Due to the latter factor, the rate of 3-year relapse-free survival rose considerably. Also, loco-regional and distant metastasis incidence was cut down due to superior ablasticity of surgery.

New approaches to the removal of protein-bound toxins from blood plasma of uremic patients

The article is devoted to the theoretical aspects of the development of the effective method for the removal of protein-bound uremic toxins. It is shown that the methods of flow and differential scanning microcalorimetry are sufficient enough for the evaluation of the degree of ligand loading of human serum albumin with protein-bound uremic toxins. The molecules of albumin isolated from blood plasma of the patients being kept on chronic dialysis are demonstrating significant alterations of conformation and complex-forming properties, the correction of which by conventional methods of extracorporeal detoxification (exhaustive dialysis, treatment on synthetic SCN carbons) are practically ineffective. Deliganding of uremic albumin may be successfully performed on conventional carbon haemosorbents upon preliminary separation of blood plasma and its dilution with acetate buffer 1:1 at pH = 5.08. Treatment of the whole blood of patients onto new mass-fractal deliganding carbon, i.e., hemosorbents of HSGD trademark. These HSGD haemosorbents quite effectively could be used for restoration of main parameters of uremic HAS molecules conformation and ligand-binding activity simultaneously with hemodialysis upon the protection by locally performed citrate anticoagulation as an easier and cheaper method for the removal of protein-bound uremic toxins.

[Use of combined treatment of rectal cancer involving metastases to regional lymph nodes]

Use of combined pre- and intraoperative radiotherapy for rectal cancer involving metastases to regional lymph nodes failed to lower incidence of loco-regional recurrences or improve 5-year results, as compared with pre-operative radiotherapy alone. Besides, distant metastasis rates remained rather high (ca.30%). However, pre-operative radiotherapy plus local SHF-hyperthermia were followed by a significant drop in loco-regional recurrence incidence (to 2.3%), as compared with surgery alone and combined treatment using pre-operative hyper-fractionated-radiotherapy (TTD 25 Gy). Distant metastasis rates dropped to 25%. Also, 5-year survival increased significantly.

Anisotropic packing and one-dimensional fluctuations of C60 molecules in carbon nanotubes

The confinement of a C60 molecule encapsulated in a cylindrical nanotube depends on the tube radius. In small tubes with radius RT approximately < 7 A, a fivefold axis of the molecule coincides with the tube axis. The interaction between C60 molecules in the nanotube is then described by a O2-rotor model on a 1D liquid chain with coupling between orientational and displacive correlations. This coupling leads to chain contraction. The structure factor of the 1D liquid is derived. In tubes with a larger radius the molecular centers of mass are displaced off the tube axis. The distinction of two groups of peapods with on- and off-axis molecules suggests an explanation of the apparent splitting of Ag modes of C60 in nanotubes measured by resonant Raman scattering.

Mathematical Model of Binding of Albumin—Bilirubin Complex to the Surface of Carbon Pyropolymer

We proposed a mathematical model and estimated the parameters of adsorption of albumin-bilirubin complex to the surface of carbon pyropolymer. Design data corresponded to the results of experimental studies. Our findings indicate that modeling of this process should take into account fractal properties of the surface of carbon pyropolymer.

Superexchange and electron correlations in alkali fullerides AC60, A=K, Rb, Cs

Superexchange interactions in alkali fullerides AC(60) are derived for C(60) molecular ions separated by interstitial alkali-metal ions. We use a multiconfiguration approach which comprises the lowest molecular orbital states of the C(60) molecule and the excited s and d states of the alkali-metal atom A. Interactions are described by the valence bond (Heitler-London) method for a complex (C(60)-A-C(60))(-) with two valence electrons. The electronic charge transfer between the alkali-metal atom and a neighboring C(60) molecule is not complete. The occupation probability of excited d and s states of the alkali atom is not negligible. In correspondence with the relative positions of the C(60) molecules and A atoms in the polymer crystal, we consider 180 degrees and 90 degrees (angle) superexchange pathways. For the former case the ground state is found to be a spin singlet separated from a triplet at approximately 20 K. For T<20 K there appear strong spin correlations for the 180 degrees superexchange pathway. The results are related to spin lattice relaxation experiments on CsC(60) in the polymerized and in the quenched cubic phase.

Valence electronic charge density of distorted C60- monomers in polymerized KC60 and RbC60

We investigate the valence electronic charge density of the C(60) (-) monomers in (C(60) (-))(n) polymer chains in K- and RbC(60) by means of a nonorthogonal tight-binding formalism using experimental data on the positions of the carbon atoms. Various configurations of the C(60) cages are considered. Starting from the ideal icosahedral C(60) structure and moving to the realistic, experimentally determined spatial configuration of the C(60) cages in K- and RbC(60), we observe a systematic increase of the electric quadrupole moments on the C(60) (-) monomers. We also confirm the validity of factorizing the charge density of a C(60) (-) monomer into an angular and a radial part.

[Evaluation of morbidity and etiological structure of acute and chronic viral hepatitis in the Sakha Republic (Yakutiia)]

The morbidity of viral hepatitis was epidemiologically analyzed and the etiological structure of severe and chronic viral hepatitis was studied in the Republic of Sakha (Yakutia). Acute viral hepatitis B, whose portion is 43.5%, was found to be of the key significance within the structure of acute viral hepatitis (AVH). Acute viral hepatitis C (with 4.7% in the AVH structure) is by far more rare. The latter is close to the value registered in other Russia's regions. Apart from the prevalence of viral hepatitis B (32.4%) an exceptionally high share of chronic hepatitis delta (24.5%) was established for the etiological structure of chronic viral hepatitis, which is a specificity of the discussed region. The epidemic situation in the Republic of Sakha (Yakutia) was stated to be linked with the mentioned extra dangerous diseases, which requires appropriate emergency measures with the prevention vaccination program against hepatitis B being a priority.

[Viral hepatitis in different population groups of Republic of Sakha (Iakutia)]

A survey for the presence of markers of viral hepatitis B, delta, C and E among different groups of the population of the arctic and agricultural zones of the Republic of Sakha (Yakutia), as well as in Yakutsk, was carried out. The survey revealed that viral hepatitides with the parenteral mechanism of the transmission of infective agents were widely spread among the population. In the arctic zone HBsAg was detected in persons aged 20 years and older in 10.8-17.1% of cases. On the average, in the arctic zone antibodies to virus delta were detected in 2.4% of cases. In different regions of the agricultural zone the detection rate of HBsAg was also high (10.4-23.8%). In the Namsk and Vilyui regions delta infection was registered among adolescents (15-19 years of age) in 8.7 and 22.4% of cases respectively. In the Mountainous region anti-delta antibodies were detected among persons aged 20 years and older in 31% of cases. The survey showed the presence of considerable differences in the detection rate of the markers of hepatitis B, depending on the ethnic origin of the examined patients. Similar tendencies were found to exist with respect to delta infection.

An efficient and stereoselective synthesis of beta-D-Arap-(1-->2)-beta-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-alpha-D-Manp, a tetrasaccharide fragment of Leishmania major lipophosphoglycan

A tetrasaccharide fragment of Leishmania major lipophosphoglycan (which seems to be involved in a biological mechanism for the parasite transmission) has been synthesised using the thioglycoside, trichloroacetimidate and halide-exchange glycosylation procedures and step-wise chain elongation strategy.

[Deletion of YNZ22 and ALU-VPA/MYCL1 loci in human colonic adenocarcinoma and postoperative prognosis]

Since deletions of the short arm of chromosome 17 are the most common genetic defects in human colorectal carcinoma (CC), we tested the YNZ22 locus (D17S30, 17p13.3) for loss of heterozygosity (LH) in adenocarcinoma and in the normal colonic mucosa of 49 CC patients, and studied the association of LH with clinicomorphological features of the tumor. Allele frequency distribution of YNZ22 did not differ for the patients and healthy people. LH in YNZ22 in the tumor was found in 33% (13/39) of all informative cases, its frequency being thrice higher in men than in women (chi 2 = 5.21, p = 0.022). The defect was associated with moderate or poor histological differentiation (P2 = 0.0055) and polyploidy > 3n (P2 = 0.0035) of tumor cells and with high incidence of post-surgery relapse or metastasis. Analysis of both YNZ22 and Alu-VpA/MycL1 (1p34.3) loci in the tumor allowed reliable relapse prognosis in 76% of the CC patients. The probability of post-surgery relapse or metastasis was estimated at no less than 67% for patients with LH in at least one of the two loci in the tumor, and at somewhat more than 20% for patients without LH.

[Anatomic resection of spleen in experiment]

The study was carried out in 35 dogs. Basic surgical techniques developed experimentally for organ-saving operations on the spleen are presented. Methods of lobar and segmental resections of the spleen based on detailed study of variants of branching of splenic artery and vein are described. Angiography visualized sharply splenic arteries after lobar and segmental resections, including the stumps of transected arteries. Ultrasonic examination, performed before operation and in different terms after it (3-360 days), specified the size, shape echostructure and anatomic relationship of the spleen with adjacent organs before and after operation.

[Actual nutrition and vitamin status of school children in the Orla region]

The actual nutrition and vitamin provision in 14-17-year-old schoolchildren in Oryol and the Oryol Region were studied within the framework of the working programme. Sanitary recommendations for vitamin prophylaxis were developed. Evidence is provided for the biomedical efficiency of vitamin prophylaxis.

Theory of distinct crystal structures of polymerized fullerides AC60, A = K, Rb, Cs: the specific role of alkalis

The polymer phases of AC60 form distinct crystal structures characterized by the mutual orientations of the (C( -)(60))(n) chains. We show that the direct electric quadrupole interaction between chains always favors the orthorhombic structure Pmnn with alternating chain orientations. However, the specific quadrupolar polarizability of the alkali metal ions leads to an indirect interchain coupling which favors the monoclinic structure I2/m with equal chain orientations. The competition between direct and indirect interactions explains the structural difference between KC60 and RbC60, CsC60.

Characterization of the elongating alpha-D-mannosyl phosphate transferase from three species of Leishmania using synthetic acceptor substrate analogues

Leishmania express lipophosphoglycans and proteophosphoglycans that contain Galbeta1-4Manalpha1-P phosphosaccharide repeat structures assembled by the sequential addition of Manalpha1-P and betaGal. The synthetic acceptor substrate Galbeta1-4Manalpha1-P-decenyl and a series of analogues were used to probe Leishmania alpha-D-mannosyl phosphate transferase activity. We show that the activity detected with Galbeta1-4Manalpha1-P-decenyl is the elongating alpha-D-mannosyl phosphate transferase associated with lipophosphoglycan biosynthesis (eMPT(LPG)). Differences in the apparent K(m) values for the donor and acceptor substrates were found using L. major, L. mexicana, and L. donovani promastigote membranes, but total activity correlated with the number of lipophosphoglycan repeats. Further comparisons showed that lesion-derived L. mexicana amastigotes, that do not express lipophosphoglycan, lack eMPT(LPG) and that nondividing L. major metacyclic promastigotes contain 5-fold less eMPT(LPG) activity than dividing procyclic promastigotes. The fine specificity of promastigote eMPT(LPG) activity was determined using 24 synthetic analogues of Galbeta1-4Manalpha1-P-decenyl. The three species gave similar results: the negative charge of the phosphodiester and the C-6 hydroxyl of the alphaMan residue are essential for substrate recognition, the latter most likely acting as a hydrogen bond acceptor. The C-6' hydroxyl of the betaGal residue is required for substrate recognition as well as for catalysis. The rate of Manalpha1-P transfer declines with increasing acceptor substrate chain length. The presence of a monosaccharide substituent at the C-3 position of the terminal betaGal residue abrogates Man-P transfer, showing that chain elongation must precede side chain modification during lipophosphoglycan biosynthesis. In contrast, substitution of the penultimate phosphosaccharide repeat does not abrogate transfer but is slightly stimulatory in L. mexicana and inhibitory in L. major.

[Preoperative thermoradiotherapy in the combined treatment of rectal tumors is the inferior ampullar segmentŏ]

Data on the examination of 260 radically-treated patients with rectal tumors in the inferior ampullar segment are presented. 107 patients received surgery alone, another 75--preoperative radiotherapy, while still another 78--preoperative thermoradiotherapy. Combined treatment of stage III tumors significantly reduced recurrence incidence and was followed by significant increase in recurrence-free survival rates. In cases of tumor disseminated to the regional lymph nodes, recurrence-free survival was observed after preoperative thermoradiation only.

C-reactive protein binds to phosphorylated carbohydrates

C-reactive protein (CRP) is a major acute phase protein in man. In order to more fully understand the physiological role of this serum protein, we have demonstrated high avidity binding for a defined chemically synthesized carbo-hydrate ligand which represents the repeating disaccharide of lipophosphoglycan, the major surface glycoconjugate of the unicellular parasite Leishmania donovani. Increasing the number of phosphorylated disaccharides in a molecule from one up to seven did not increase the avidity for CRP, however increasing this to 10 potential CRP binding sites did. In order to define the important features of this complex and variable structure for CRP binding we competed CRP binding to whole Leishmania parasites with amino, sulfated, phosphorylated, and unsubstituted monosaccharides, of which only phosphorylated monosaccharides were able to inhibit. Both the carbohydrate and the position of phosphorylation influenced the avidity for CRP. Synthetic oligosaccharides and phospho-oligosaccharides of various lengths and conformations were used to define the structural requirements for CRP recognition. The optimum structure for recognition of a single phosphate group was between two monosaccharide pyranose rings, and within a linear rather than a cyclic molecule. This stresses the importance of the interaction of the CRP binding site with both the carbohydrate and the phosphate group. CRP function may be mediated via the recognition of large arrays of phosphorylated carbohydrates as are characteristic of the surface of microorganisms.

Extracellular signal-related kinase (ERK) and p38 mitogen-activated protein (MAP) kinases differentially regulate the lipopolysaccharide-mediated induction of inducible nitric oxide synthase and IL-12 in macrophages: Leishmania phosphoglycans subvert macrophage IL-12 production by targeting ERK MAP kinase

Macrophage activation by cytokines or microbial products such as LPS results in the induction and release of several key immune effector molecules including NO and IL-12. These have been shown to play crucial roles in the development of immunity to intracellular pathogens such as Leishmania. The molecular mechanisms underlying the induction of these effector molecules are not fully understood. We now show that the extracellular signal-related kinase (ERK) and p38 mitogen-activated protein (MAP) kinases play differential roles in the regulation of LPS-stimulated inducible NO synthase and IL-12 gene expression. In macrophages, LPS stimulates the simultaneous activation of all three classes of MAP kinases, ERK, c-jun N-terminal kinase, and p38, albeit with differential activation kinetics. However, studies using inhibitors selective for ERK (PD98059) and p38 (SB203580) show that while p38 plays an essential role in the induction of inducible NO synthase, ERK MAP kinases play only a minor role in promoting NO generation. In contrast, while p38 promotes induction of IL-12 (p40) mRNA, ERK activation suppresses LPS-mediated IL-12 transcription. The biological relevance of these regulatory signals is demonstrated by our finding that Leishmania lipophosphoglycans, which promote parasite survival, act by stimulating ERK MAP kinase to inhibit macrophage IL-12 production. Thus, as ERK and p38 MAP kinases differentially regulate the induction of the macrophage effector molecules, inducible NO synthase and IL-12, these kinases are potential targets not only for the development of novel strategies to combat intracellular pathogens but also for therapeutic immunomodulation.

The preparation of neoglycoconjugates containing inter-saccharide phosphodiester linkages as potential anti-Leishmania vaccines

The Leishmania express complex glycoconjugates containing phosphosaccharide repeat units at all stages of their life-cycle. One of these molecules, lipophosphoglycan (LPG) has been suggested to be a vaccine candidate. To assess the immunological properties of Leishmania phosphosaccharides, we have prepared neoglycoproteins and neoglycolipids containing synthetic Leishmania phosphosaccharide repeats. The coupling procedure uses the dec-9-enyl spacer of previously synthesised phosphosaccharides for linkage to protein and phospholipid. This alkene moiety is converted by ozonolysis to an aldehyde which is then attached to protein and phospholipid amino groups by reductive amination. The procedure produces neoglycoconjugates in good yield and without compromising the labile phosphodiester linkages within the phosphosaccharide chains.

Regulation of the miniature plasma membrane Ca(2+) channel I(min) by inositol 1,4,5-trisphosphate receptors

I(min) is a plasma membrane-located, Ca(2+)-selective channel that is activated by store depletion and regulated by inositol 1,4, 5-trisphosphate (IP(3)). In the present work we examined the coupling between I(min) and IP(3) receptors in excised plasma membrane patches from A431 cells. I(min) was recorded in cell-attached mode and the patches were excised into medium containing IP(3). In about 50% of experiments excision caused the loss of activation of I(min) by IP(3.) In the remaining patches activation of I(min) by IP(3) was lost upon extensive washes of the patch surface. The ability of IP(3) to activate I(min) was restored by treating the patches with rat cerebellar microsomes reach in IP(3) receptors but not by control forebrain microsomes. The re-activated I(min) had the same kinetic properties as I(min) when it is activated by Ca(2+)-mobilizing agonists in intact cells and by IP(3) in excised plasma membrane patches and it was inhibited by the I(crac) inhibitor SKF95365. We propose that I(min) is a form of I(crac) and is gated by IP(3) receptors.

[Adjuvant radiotherapy in the combined treatment of rectal cancer]

Radiotherapy was given postoperatively to 37 out of 81 patients with metastases into the regional lymph nodes (stage C after Dukes) to prevent relapse. All the patients had undergone radical surgery. No significant decrease in relapse incidence could be achieved unless an absorbed dose of 40 Gy was received postoperatively. However, combined treatment failed to produce a significant rise in five-year survival due to deaths from distant metastases.

Regulation of macrophage IL-12 synthesis by Leishmania phosphoglycans

It is now generally accepted that IFN-gamma, secreted by Th1 cells, is the most potent cytokine leading to macrophage activation and host resistance against infection with the intracellular protozoan parasite Leishmania. It is also established that IL-12 is a critical cytokine involved in the differentiation and expansion of Th1 cells. Therefore, the ability of Leishmania parasites to actively suppress IL-12 production by host macrophages may be an important strategy for parasite survival. Here we report that a major parasite cell surface molecule, phosphoglycan (PG), of Leishmania could selectively inhibit the synthesis of IL-12(p40, p70) by activated murine macrophages. Furthermore, synthetic PG (sPG) was able to inhibit IL-12 release in a dose-dependent manner. Inhibition was dependent on the galactose(beta1-4)mannose(alpha1)-PO4 repeating units and not the glycophosphoinositol lipid anchor of lipophosphoglycan. At the concentration used, sPG had no effect on the release of TNF-alpha or IL-6 in activated macrophages. The inhibition of IL-12(p40) production was at the transcriptional level, but was not mediated through NF kappaB inhibition. These data demonstrate that PG may be an important molecule for the establishment and survival of the parasite in permissive hosts.

[Growth of stable clones of mouse fibroblast cell line C3H10T1/2 expressing the human retinoblastoma gene product]

Phosphorylation and dephosphorylation of the retinoblastoma gene product (pRB) are recognized as necessary events in the cell cycle progression. To study the role of pRB in regulation of cell proliferation, the stable cell lines with constitutive expression of the exogenous RB gene can be employed. In order to obtain such cell lines in this work C3H10T1/2 mouse fibroblasts were infected with defective retrovirus encompassing the RB and Neo gene conferring resistance to geniticine (G418). The pRB production and its phosphorylation pattern were analyzed by immunoblotting in cell lysates considering well known data on correlation between pRB phosphorylation pattern and its electrophoretic mobility. Cell lines subjected to G418 selection with the following cloning procedure were identical to the control cells expressing beta-galactosidase, when compared for pRB production and phosphorylation in the cell cycle stages characterized by hyperphosphorylated pRB. However, cells of the experimental cell lines hypophosphorylated pRB much faster and accumulated much more underphosphorylated protein compared to the control cell lines. The doubling time of the cells was not affected either by changes in the pRB phosphorylation pattern or by its overproduction during separate cell cycle stages. These results suggest that maintaining of the physiological level of pRB phosphorylation in cycling cells is strictly controlled and is considered to be a more important condition of the cell cycle progression than pRB dephosphorylation.